diff --git a/uppsrc/plugin/box2d/Box2D.h b/uppsrc/plugin/box2d/Box2D.h new file mode 100644 index 000000000..2e480dcb9 --- /dev/null +++ b/uppsrc/plugin/box2d/Box2D.h @@ -0,0 +1,62 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef BOX2D_H +#define BOX2D_H + +/** +\mainpage Box2D API Documentation + +\section intro_sec Getting Started + +For documentation please see http://box2d.org/documentation.html + +For discussion please visit http://box2d.org/forum +*/ + +// These include files constitute the main Box2D API + +#include "b2Settings.h" + +#include "b2CircleShape.h" +#include "b2PolygonShape.h" + +#include "b2BroadPhase.h" +#include "b2Distance.h" +#include "b2DynamicTree.h" +#include "b2TimeOfImpact.h" + +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2WorldCallbacks.h" +#include "b2TimeStep.h" +#include "b2World.h" + +#include "b2Contact.h" + +#include "b2DistanceJoint.h" +#include "b2FrictionJoint.h" +#include "b2GearJoint.h" +#include "b2LineJoint.h" +#include "b2MouseJoint.h" +#include "b2PrismaticJoint.h" +#include "b2PulleyJoint.h" +#include "b2RevoluteJoint.h" +#include "b2WeldJoint.h" + +#endif diff --git a/uppsrc/plugin/box2d/b2BlockAllocator.cpp b/uppsrc/plugin/box2d/b2BlockAllocator.cpp new file mode 100644 index 000000000..fb73d369a --- /dev/null +++ b/uppsrc/plugin/box2d/b2BlockAllocator.cpp @@ -0,0 +1,205 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2BlockAllocator.h" +#include +#include +#include +#include + +int32 b2BlockAllocator::s_blockSizes[b2_blockSizes] = +{ + 16, // 0 + 32, // 1 + 64, // 2 + 96, // 3 + 128, // 4 + 160, // 5 + 192, // 6 + 224, // 7 + 256, // 8 + 320, // 9 + 384, // 10 + 448, // 11 + 512, // 12 + 640, // 13 +}; +uint8 b2BlockAllocator::s_blockSizeLookup[b2_maxBlockSize + 1]; +bool b2BlockAllocator::s_blockSizeLookupInitialized; + +struct b2Chunk +{ + int32 blockSize; + b2Block* blocks; +}; + +struct b2Block +{ + b2Block* next; +}; + +b2BlockAllocator::b2BlockAllocator() +{ + b2Assert(b2_blockSizes < UCHAR_MAX); + + m_chunkSpace = b2_chunkArrayIncrement; + m_chunkCount = 0; + m_chunks = (b2Chunk*)b2Alloc(m_chunkSpace * sizeof(b2Chunk)); + + memset(m_chunks, 0, m_chunkSpace * sizeof(b2Chunk)); + memset(m_freeLists, 0, sizeof(m_freeLists)); + + if (s_blockSizeLookupInitialized == false) + { + int32 j = 0; + for (int32 i = 1; i <= b2_maxBlockSize; ++i) + { + b2Assert(j < b2_blockSizes); + if (i <= s_blockSizes[j]) + { + s_blockSizeLookup[i] = (uint8)j; + } + else + { + ++j; + s_blockSizeLookup[i] = (uint8)j; + } + } + + s_blockSizeLookupInitialized = true; + } +} + +b2BlockAllocator::~b2BlockAllocator() +{ + for (int32 i = 0; i < m_chunkCount; ++i) + { + b2Free(m_chunks[i].blocks); + } + + b2Free(m_chunks); +} + +void* b2BlockAllocator::Allocate(int32 size) +{ + if (size == 0) + return NULL; + + b2Assert(0 < size && size <= b2_maxBlockSize); + + int32 index = s_blockSizeLookup[size]; + b2Assert(0 <= index && index < b2_blockSizes); + + if (m_freeLists[index]) + { + b2Block* block = m_freeLists[index]; + m_freeLists[index] = block->next; + return block; + } + else + { + if (m_chunkCount == m_chunkSpace) + { + b2Chunk* oldChunks = m_chunks; + m_chunkSpace += b2_chunkArrayIncrement; + m_chunks = (b2Chunk*)b2Alloc(m_chunkSpace * sizeof(b2Chunk)); + memcpy(m_chunks, oldChunks, m_chunkCount * sizeof(b2Chunk)); + memset(m_chunks + m_chunkCount, 0, b2_chunkArrayIncrement * sizeof(b2Chunk)); + b2Free(oldChunks); + } + + b2Chunk* chunk = m_chunks + m_chunkCount; + chunk->blocks = (b2Block*)b2Alloc(b2_chunkSize); +#if defined(_DEBUG) + memset(chunk->blocks, 0xcd, b2_chunkSize); +#endif + int32 blockSize = s_blockSizes[index]; + chunk->blockSize = blockSize; + int32 blockCount = b2_chunkSize / blockSize; + b2Assert(blockCount * blockSize <= b2_chunkSize); + for (int32 i = 0; i < blockCount - 1; ++i) + { + b2Block* block = (b2Block*)((int8*)chunk->blocks + blockSize * i); + b2Block* next = (b2Block*)((int8*)chunk->blocks + blockSize * (i + 1)); + block->next = next; + } + b2Block* last = (b2Block*)((int8*)chunk->blocks + blockSize * (blockCount - 1)); + last->next = NULL; + + m_freeLists[index] = chunk->blocks->next; + ++m_chunkCount; + + return chunk->blocks; + } +} + +void b2BlockAllocator::Free(void* p, int32 size) +{ + if (size == 0) + { + return; + } + + b2Assert(0 < size && size <= b2_maxBlockSize); + + int32 index = s_blockSizeLookup[size]; + b2Assert(0 <= index && index < b2_blockSizes); + +#ifdef _DEBUG + // Verify the memory address and size is valid. + int32 blockSize = s_blockSizes[index]; + bool found = false; + for (int32 i = 0; i < m_chunkCount; ++i) + { + b2Chunk* chunk = m_chunks + i; + if (chunk->blockSize != blockSize) + { + b2Assert( (int8*)p + blockSize <= (int8*)chunk->blocks || + (int8*)chunk->blocks + b2_chunkSize <= (int8*)p); + } + else + { + if ((int8*)chunk->blocks <= (int8*)p && (int8*)p + blockSize <= (int8*)chunk->blocks + b2_chunkSize) + { + found = true; + } + } + } + + b2Assert(found); + + memset(p, 0xfd, blockSize); +#endif + + b2Block* block = (b2Block*)p; + block->next = m_freeLists[index]; + m_freeLists[index] = block; +} + +void b2BlockAllocator::Clear() +{ + for (int32 i = 0; i < m_chunkCount; ++i) + { + b2Free(m_chunks[i].blocks); + } + + m_chunkCount = 0; + memset(m_chunks, 0, m_chunkSpace * sizeof(b2Chunk)); + + memset(m_freeLists, 0, sizeof(m_freeLists)); +} diff --git a/uppsrc/plugin/box2d/b2BlockAllocator.h b/uppsrc/plugin/box2d/b2BlockAllocator.h new file mode 100644 index 000000000..9603922a7 --- /dev/null +++ b/uppsrc/plugin/box2d/b2BlockAllocator.h @@ -0,0 +1,59 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_BLOCK_ALLOCATOR_H +#define B2_BLOCK_ALLOCATOR_H + +#include "b2Settings.h" + +const int32 b2_chunkSize = 4096; +const int32 b2_maxBlockSize = 640; +const int32 b2_blockSizes = 14; +const int32 b2_chunkArrayIncrement = 128; + +struct b2Block; +struct b2Chunk; + +// This is a small object allocator used for allocating small +// objects that persist for more than one time step. +// See: http://www.codeproject.com/useritems/Small_Block_Allocator.asp +class b2BlockAllocator +{ +public: + b2BlockAllocator(); + ~b2BlockAllocator(); + + void* Allocate(int32 size); + void Free(void* p, int32 size); + + void Clear(); + +private: + + b2Chunk* m_chunks; + int32 m_chunkCount; + int32 m_chunkSpace; + + b2Block* m_freeLists[b2_blockSizes]; + + static int32 s_blockSizes[b2_blockSizes]; + static uint8 s_blockSizeLookup[b2_maxBlockSize + 1]; + static bool s_blockSizeLookupInitialized; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2Body.cpp b/uppsrc/plugin/box2d/b2Body.cpp new file mode 100644 index 000000000..aacdd38f5 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Body.cpp @@ -0,0 +1,470 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2World.h" +#include "b2Contact.h" +#include "b2Joint.h" + +b2Body::b2Body(const b2BodyDef* bd, b2World* world) +{ + b2Assert(bd->position.IsValid()); + b2Assert(bd->linearVelocity.IsValid()); + b2Assert(b2IsValid(bd->angle)); + b2Assert(b2IsValid(bd->angularVelocity)); + b2Assert(b2IsValid(bd->inertiaScale) && bd->inertiaScale >= 0.0f); + b2Assert(b2IsValid(bd->angularDamping) && bd->angularDamping >= 0.0f); + b2Assert(b2IsValid(bd->linearDamping) && bd->linearDamping >= 0.0f); + + m_flags = 0; + + if (bd->bullet) + { + m_flags |= e_bulletFlag; + } + if (bd->fixedRotation) + { + m_flags |= e_fixedRotationFlag; + } + if (bd->allowSleep) + { + m_flags |= e_autoSleepFlag; + } + if (bd->awake) + { + m_flags |= e_awakeFlag; + } + if (bd->active) + { + m_flags |= e_activeFlag; + } + + m_world = world; + + m_xf.position = bd->position; + m_xf.R.Set(bd->angle); + + m_sweep.localCenter.SetZero(); + m_sweep.a0 = m_sweep.a = bd->angle; + m_sweep.c0 = m_sweep.c = b2Mul(m_xf, m_sweep.localCenter); + + m_jointList = NULL; + m_contactList = NULL; + m_prev = NULL; + m_next = NULL; + + m_linearVelocity = bd->linearVelocity; + m_angularVelocity = bd->angularVelocity; + + m_linearDamping = bd->linearDamping; + m_angularDamping = bd->angularDamping; + + m_force.SetZero(); + m_torque = 0.0f; + + m_sleepTime = 0.0f; + + m_type = bd->type; + + if (m_type == b2_dynamicBody) + { + m_mass = 1.0f; + m_invMass = 1.0f; + } + else + { + m_mass = 0.0f; + m_invMass = 0.0f; + } + + m_I = 0.0f; + m_invI = 0.0f; + + m_userData = bd->userData; + + m_fixtureList = NULL; + m_fixtureCount = 0; +} + +b2Body::~b2Body() +{ + // shapes and joints are destroyed in b2World::Destroy +} + +void b2Body::SetType(b2BodyType type) +{ + if (m_type == type) + { + return; + } + + m_type = type; + + ResetMassData(); + + if (m_type == b2_staticBody) + { + m_linearVelocity.SetZero(); + m_angularVelocity = 0.0f; + } + + SetAwake(true); + + m_force.SetZero(); + m_torque = 0.0f; + + // Since the body type changed, we need to flag contacts for filtering. + for (b2ContactEdge* ce = m_contactList; ce; ce = ce->next) + { + ce->contact->FlagForFiltering(); + } +} + +b2Fixture* b2Body::CreateFixture(const b2FixtureDef* def) +{ + b2Assert(m_world->IsLocked() == false); + if (m_world->IsLocked() == true) + { + return NULL; + } + + b2BlockAllocator* allocator = &m_world->m_blockAllocator; + + void* memory = allocator->Allocate(sizeof(b2Fixture)); + b2Fixture* fixture = new (memory) b2Fixture; + fixture->Create(allocator, this, def); + + if (m_flags & e_activeFlag) + { + b2BroadPhase* broadPhase = &m_world->m_contactManager.m_broadPhase; + fixture->CreateProxy(broadPhase, m_xf); + } + + fixture->m_next = m_fixtureList; + m_fixtureList = fixture; + ++m_fixtureCount; + + fixture->m_body = this; + + // Adjust mass properties if needed. + if (fixture->m_density > 0.0f) + { + ResetMassData(); + } + + // Let the world know we have a new fixture. This will cause new contacts + // to be created at the beginning of the next time step. + m_world->m_flags |= b2World::e_newFixture; + + return fixture; +} + +b2Fixture* b2Body::CreateFixture(const b2Shape* shape, float32 density) +{ + b2FixtureDef def; + def.shape = shape; + def.density = density; + + return CreateFixture(&def); +} + +void b2Body::DestroyFixture(b2Fixture* fixture) +{ + b2Assert(m_world->IsLocked() == false); + if (m_world->IsLocked() == true) + { + return; + } + + b2Assert(fixture->m_body == this); + + // Remove the fixture from this body's singly linked list. + b2Assert(m_fixtureCount > 0); + b2Fixture** node = &m_fixtureList; + bool found = false; + while (*node != NULL) + { + if (*node == fixture) + { + *node = fixture->m_next; + found = true; + break; + } + + node = &(*node)->m_next; + } + + // You tried to remove a shape that is not attached to this body. + b2Assert(found); + + // Destroy any contacts associated with the fixture. + b2ContactEdge* edge = m_contactList; + while (edge) + { + b2Contact* c = edge->contact; + edge = edge->next; + + b2Fixture* fixtureA = c->GetFixtureA(); + b2Fixture* fixtureB = c->GetFixtureB(); + + if (fixture == fixtureA || fixture == fixtureB) + { + // This destroys the contact and removes it from + // this body's contact list. + m_world->m_contactManager.Destroy(c); + } + } + + b2BlockAllocator* allocator = &m_world->m_blockAllocator; + + if (m_flags & e_activeFlag) + { + b2Assert(fixture->m_proxyId != b2BroadPhase::e_nullProxy); + b2BroadPhase* broadPhase = &m_world->m_contactManager.m_broadPhase; + fixture->DestroyProxy(broadPhase); + } + else + { + b2Assert(fixture->m_proxyId == b2BroadPhase::e_nullProxy); + } + + fixture->Destroy(allocator); + fixture->m_body = NULL; + fixture->m_next = NULL; + fixture->~b2Fixture(); + allocator->Free(fixture, sizeof(b2Fixture)); + + --m_fixtureCount; + + // Reset the mass data. + ResetMassData(); +} + +void b2Body::ResetMassData() +{ + // Compute mass data from shapes. Each shape has its own density. + m_mass = 0.0f; + m_invMass = 0.0f; + m_I = 0.0f; + m_invI = 0.0f; + m_sweep.localCenter.SetZero(); + + // Static and kinematic bodies have zero mass. + if (m_type == b2_staticBody || m_type == b2_kinematicBody) + { + m_sweep.c0 = m_sweep.c = m_xf.position; + return; + } + + b2Assert(m_type == b2_dynamicBody); + + // Accumulate mass over all fixtures. + b2Vec2 center = b2Vec2_zero; + for (b2Fixture* f = m_fixtureList; f; f = f->m_next) + { + if (f->m_density == 0.0f) + { + continue; + } + + b2MassData massData; + f->GetMassData(&massData); + m_mass += massData.mass; + center += massData.mass * massData.center; + m_I += massData.I; + } + + // Compute center of mass. + if (m_mass > 0.0f) + { + m_invMass = 1.0f / m_mass; + center *= m_invMass; + } + else + { + // Force all dynamic bodies to have a positive mass. + m_mass = 1.0f; + m_invMass = 1.0f; + } + + if (m_I > 0.0f && (m_flags & e_fixedRotationFlag) == 0) + { + // Center the inertia about the center of mass. + m_I -= m_mass * b2Dot(center, center); + b2Assert(m_I > 0.0f); + m_invI = 1.0f / m_I; + + } + else + { + m_I = 0.0f; + m_invI = 0.0f; + } + + // Move center of mass. + b2Vec2 oldCenter = m_sweep.c; + m_sweep.localCenter = center; + m_sweep.c0 = m_sweep.c = b2Mul(m_xf, m_sweep.localCenter); + + // Update center of mass velocity. + m_linearVelocity += b2Cross(m_angularVelocity, m_sweep.c - oldCenter); +} + +void b2Body::SetMassData(const b2MassData* massData) +{ + b2Assert(m_world->IsLocked() == false); + if (m_world->IsLocked() == true) + { + return; + } + + if (m_type != b2_dynamicBody) + { + return; + } + + m_invMass = 0.0f; + m_I = 0.0f; + m_invI = 0.0f; + + m_mass = massData->mass; + if (m_mass <= 0.0f) + { + m_mass = 1.0f; + } + + m_invMass = 1.0f / m_mass; + + if (massData->I > 0.0f && (m_flags & b2Body::e_fixedRotationFlag) == 0) + { + m_I = massData->I - m_mass * b2Dot(massData->center, massData->center); + b2Assert(m_I > 0.0f); + m_invI = 1.0f / m_I; + } + + // Move center of mass. + b2Vec2 oldCenter = m_sweep.c; + m_sweep.localCenter = massData->center; + m_sweep.c0 = m_sweep.c = b2Mul(m_xf, m_sweep.localCenter); + + // Update center of mass velocity. + m_linearVelocity += b2Cross(m_angularVelocity, m_sweep.c - oldCenter); +} + +bool b2Body::ShouldCollide(const b2Body* other) const +{ + // At least one body should be dynamic. + if (m_type != b2_dynamicBody && other->m_type != b2_dynamicBody) + { + return false; + } + + // Does a joint prevent collision? + for (b2JointEdge* jn = m_jointList; jn; jn = jn->next) + { + if (jn->other == other) + { + if (jn->joint->m_collideConnected == false) + { + return false; + } + } + } + + return true; +} + +void b2Body::SetTransform(const b2Vec2& position, float32 angle) +{ + b2Assert(m_world->IsLocked() == false); + if (m_world->IsLocked() == true) + { + return; + } + + m_xf.R.Set(angle); + m_xf.position = position; + + m_sweep.c0 = m_sweep.c = b2Mul(m_xf, m_sweep.localCenter); + m_sweep.a0 = m_sweep.a = angle; + + b2BroadPhase* broadPhase = &m_world->m_contactManager.m_broadPhase; + for (b2Fixture* f = m_fixtureList; f; f = f->m_next) + { + f->Synchronize(broadPhase, m_xf, m_xf); + } + + m_world->m_contactManager.FindNewContacts(); +} + +void b2Body::SynchronizeFixtures() +{ + b2Transform xf1; + xf1.R.Set(m_sweep.a0); + xf1.position = m_sweep.c0 - b2Mul(xf1.R, m_sweep.localCenter); + + b2BroadPhase* broadPhase = &m_world->m_contactManager.m_broadPhase; + for (b2Fixture* f = m_fixtureList; f; f = f->m_next) + { + f->Synchronize(broadPhase, xf1, m_xf); + } +} + +void b2Body::SetActive(bool flag) +{ + if (flag == IsActive()) + { + return; + } + + if (flag) + { + m_flags |= e_activeFlag; + + // Create all proxies. + b2BroadPhase* broadPhase = &m_world->m_contactManager.m_broadPhase; + for (b2Fixture* f = m_fixtureList; f; f = f->m_next) + { + f->CreateProxy(broadPhase, m_xf); + } + + // Contacts are created the next time step. + } + else + { + m_flags &= ~e_activeFlag; + + // Destroy all proxies. + b2BroadPhase* broadPhase = &m_world->m_contactManager.m_broadPhase; + for (b2Fixture* f = m_fixtureList; f; f = f->m_next) + { + f->DestroyProxy(broadPhase); + } + + // Destroy the attached contacts. + b2ContactEdge* ce = m_contactList; + while (ce) + { + b2ContactEdge* ce0 = ce; + ce = ce->next; + m_world->m_contactManager.Destroy(ce0->contact); + } + m_contactList = NULL; + } +} \ No newline at end of file diff --git a/uppsrc/plugin/box2d/b2Body.h b/uppsrc/plugin/box2d/b2Body.h new file mode 100644 index 000000000..54c9af24d --- /dev/null +++ b/uppsrc/plugin/box2d/b2Body.h @@ -0,0 +1,802 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_BODY_H +#define B2_BODY_H + +#include "b2Math.h" +#include "b2Shape.h" +#include + +class b2Fixture; +class b2Joint; +class b2Contact; +class b2Controller; +class b2World; +struct b2FixtureDef; +struct b2JointEdge; +struct b2ContactEdge; + +/// The body type. +/// static: zero mass, zero velocity, may be manually moved +/// kinematic: zero mass, non-zero velocity set by user, moved by solver +/// dynamic: positive mass, non-zero velocity determined by forces, moved by solver +enum b2BodyType +{ + b2_staticBody = 0, + b2_kinematicBody, + b2_dynamicBody, +}; + +/// A body definition holds all the data needed to construct a rigid body. +/// You can safely re-use body definitions. Shapes are added to a body after construction. +struct b2BodyDef +{ + /// This constructor sets the body definition default values. + b2BodyDef() + { + userData = NULL; + position.Set(0.0f, 0.0f); + angle = 0.0f; + linearVelocity.Set(0.0f, 0.0f); + angularVelocity = 0.0f; + linearDamping = 0.0f; + angularDamping = 0.0f; + allowSleep = true; + awake = true; + fixedRotation = false; + bullet = false; + type = b2_staticBody; + active = true; + inertiaScale = 1.0f; + } + + /// The body type: static, kinematic, or dynamic. + /// Note: if a dynamic body would have zero mass, the mass is set to one. + b2BodyType type; + + /// The world position of the body. Avoid creating bodies at the origin + /// since this can lead to many overlapping shapes. + b2Vec2 position; + + /// The world angle of the body in radians. + float32 angle; + + /// The linear velocity of the body's origin in world co-ordinates. + b2Vec2 linearVelocity; + + /// The angular velocity of the body. + float32 angularVelocity; + + /// Linear damping is use to reduce the linear velocity. The damping parameter + /// can be larger than 1.0f but the damping effect becomes sensitive to the + /// time step when the damping parameter is large. + float32 linearDamping; + + /// Angular damping is use to reduce the angular velocity. The damping parameter + /// can be larger than 1.0f but the damping effect becomes sensitive to the + /// time step when the damping parameter is large. + float32 angularDamping; + + /// Set this flag to false if this body should never fall asleep. Note that + /// this increases CPU usage. + bool allowSleep; + + /// Is this body initially awake or sleeping? + bool awake; + + /// Should this body be prevented from rotating? Useful for characters. + bool fixedRotation; + + /// Is this a fast moving body that should be prevented from tunneling through + /// other moving bodies? Note that all bodies are prevented from tunneling through + /// kinematic and static bodies. This setting is only considered on dynamic bodies. + /// @warning You should use this flag sparingly since it increases processing time. + bool bullet; + + /// Does this body start out active? + bool active; + + /// Use this to store application specific body data. + void* userData; + + /// Experimental: scales the inertia tensor. + float32 inertiaScale; +}; + +/// A rigid body. These are created via b2World::CreateBody. +class b2Body +{ +public: + /// Creates a fixture and attach it to this body. Use this function if you need + /// to set some fixture parameters, like friction. Otherwise you can create the + /// fixture directly from a shape. + /// If the density is non-zero, this function automatically updates the mass of the body. + /// Contacts are not created until the next time step. + /// @param def the fixture definition. + /// @warning This function is locked during callbacks. + b2Fixture* CreateFixture(const b2FixtureDef* def); + + /// Creates a fixture from a shape and attach it to this body. + /// This is a convenience function. Use b2FixtureDef if you need to set parameters + /// like friction, restitution, user data, or filtering. + /// If the density is non-zero, this function automatically updates the mass of the body. + /// @param shape the shape to be cloned. + /// @param density the shape density (set to zero for static bodies). + /// @warning This function is locked during callbacks. + b2Fixture* CreateFixture(const b2Shape* shape, float32 density); + + /// Destroy a fixture. This removes the fixture from the broad-phase and + /// destroys all contacts associated with this fixture. This will + /// automatically adjust the mass of the body if the body is dynamic and the + /// fixture has positive density. + /// All fixtures attached to a body are implicitly destroyed when the body is destroyed. + /// @param fixture the fixture to be removed. + /// @warning This function is locked during callbacks. + void DestroyFixture(b2Fixture* fixture); + + /// Set the position of the body's origin and rotation. + /// This breaks any contacts and wakes the other bodies. + /// Manipulating a body's transform may cause non-physical behavior. + /// @param position the world position of the body's local origin. + /// @param angle the world rotation in radians. + void SetTransform(const b2Vec2& position, float32 angle); + + /// Get the body transform for the body's origin. + /// @return the world transform of the body's origin. + const b2Transform& GetTransform() const; + + /// Get the world body origin position. + /// @return the world position of the body's origin. + const b2Vec2& GetPosition() const; + + /// Get the angle in radians. + /// @return the current world rotation angle in radians. + float32 GetAngle() const; + + /// Get the world position of the center of mass. + const b2Vec2& GetWorldCenter() const; + + /// Get the local position of the center of mass. + const b2Vec2& GetLocalCenter() const; + + /// Set the linear velocity of the center of mass. + /// @param v the new linear velocity of the center of mass. + void SetLinearVelocity(const b2Vec2& v); + + /// Get the linear velocity of the center of mass. + /// @return the linear velocity of the center of mass. + b2Vec2 GetLinearVelocity() const; + + /// Set the angular velocity. + /// @param omega the new angular velocity in radians/second. + void SetAngularVelocity(float32 omega); + + /// Get the angular velocity. + /// @return the angular velocity in radians/second. + float32 GetAngularVelocity() const; + + /// Apply a force at a world point. If the force is not + /// applied at the center of mass, it will generate a torque and + /// affect the angular velocity. This wakes up the body. + /// @param force the world force vector, usually in Newtons (N). + /// @param point the world position of the point of application. + void ApplyForce(const b2Vec2& force, const b2Vec2& point); + + /// Apply a torque. This affects the angular velocity + /// without affecting the linear velocity of the center of mass. + /// This wakes up the body. + /// @param torque about the z-axis (out of the screen), usually in N-m. + void ApplyTorque(float32 torque); + + /// Apply an impulse at a point. This immediately modifies the velocity. + /// It also modifies the angular velocity if the point of application + /// is not at the center of mass. This wakes up the body. + /// @param impulse the world impulse vector, usually in N-seconds or kg-m/s. + /// @param point the world position of the point of application. + void ApplyLinearImpulse(const b2Vec2& impulse, const b2Vec2& point); + + /// Apply an angular impulse. + /// @param impulse the angular impulse in units of kg*m*m/s + void ApplyAngularImpulse(float32 impulse); + + /// Get the total mass of the body. + /// @return the mass, usually in kilograms (kg). + float32 GetMass() const; + + /// Get the rotational inertia of the body about the local origin. + /// @return the rotational inertia, usually in kg-m^2. + float32 GetInertia() const; + + /// Get the mass data of the body. + /// @return a struct containing the mass, inertia and center of the body. + void GetMassData(b2MassData* data) const; + + /// Set the mass properties to override the mass properties of the fixtures. + /// Note that this changes the center of mass position. + /// Note that creating or destroying fixtures can also alter the mass. + /// This function has no effect if the body isn't dynamic. + /// @param massData the mass properties. + void SetMassData(const b2MassData* data); + + /// This resets the mass properties to the sum of the mass properties of the fixtures. + /// This normally does not need to be called unless you called SetMassData to override + /// the mass and you later want to reset the mass. + void ResetMassData(); + + /// Get the world coordinates of a point given the local coordinates. + /// @param localPoint a point on the body measured relative the the body's origin. + /// @return the same point expressed in world coordinates. + b2Vec2 GetWorldPoint(const b2Vec2& localPoint) const; + + /// Get the world coordinates of a vector given the local coordinates. + /// @param localVector a vector fixed in the body. + /// @return the same vector expressed in world coordinates. + b2Vec2 GetWorldVector(const b2Vec2& localVector) const; + + /// Gets a local point relative to the body's origin given a world point. + /// @param a point in world coordinates. + /// @return the corresponding local point relative to the body's origin. + b2Vec2 GetLocalPoint(const b2Vec2& worldPoint) const; + + /// Gets a local vector given a world vector. + /// @param a vector in world coordinates. + /// @return the corresponding local vector. + b2Vec2 GetLocalVector(const b2Vec2& worldVector) const; + + /// Get the world linear velocity of a world point attached to this body. + /// @param a point in world coordinates. + /// @return the world velocity of a point. + b2Vec2 GetLinearVelocityFromWorldPoint(const b2Vec2& worldPoint) const; + + /// Get the world velocity of a local point. + /// @param a point in local coordinates. + /// @return the world velocity of a point. + b2Vec2 GetLinearVelocityFromLocalPoint(const b2Vec2& localPoint) const; + + /// Get the linear damping of the body. + float32 GetLinearDamping() const; + + /// Set the linear damping of the body. + void SetLinearDamping(float32 linearDamping); + + /// Get the angular damping of the body. + float32 GetAngularDamping() const; + + /// Set the angular damping of the body. + void SetAngularDamping(float32 angularDamping); + + /// Set the type of this body. This may alter the mass and velocity. + void SetType(b2BodyType type); + + /// Get the type of this body. + b2BodyType GetType() const; + + /// Should this body be treated like a bullet for continuous collision detection? + void SetBullet(bool flag); + + /// Is this body treated like a bullet for continuous collision detection? + bool IsBullet() const; + + /// You can disable sleeping on this body. If you disable sleeping, the + /// body will be woken. + void SetSleepingAllowed(bool flag); + + /// Is this body allowed to sleep + bool IsSleepingAllowed() const; + + /// Set the sleep state of the body. A sleeping body has very + /// low CPU cost. + /// @param flag set to true to put body to sleep, false to wake it. + void SetAwake(bool flag); + + /// Get the sleeping state of this body. + /// @return true if the body is sleeping. + bool IsAwake() const; + + /// Set the active state of the body. An inactive body is not + /// simulated and cannot be collided with or woken up. + /// If you pass a flag of true, all fixtures will be added to the + /// broad-phase. + /// If you pass a flag of false, all fixtures will be removed from + /// the broad-phase and all contacts will be destroyed. + /// Fixtures and joints are otherwise unaffected. You may continue + /// to create/destroy fixtures and joints on inactive bodies. + /// Fixtures on an inactive body are implicitly inactive and will + /// not participate in collisions, ray-casts, or queries. + /// Joints connected to an inactive body are implicitly inactive. + /// An inactive body is still owned by a b2World object and remains + /// in the body list. + void SetActive(bool flag); + + /// Get the active state of the body. + bool IsActive() const; + + /// Set this body to have fixed rotation. This causes the mass + /// to be reset. + void SetFixedRotation(bool flag); + + /// Does this body have fixed rotation? + bool IsFixedRotation() const; + + /// Get the list of all fixtures attached to this body. + b2Fixture* GetFixtureList(); + const b2Fixture* GetFixtureList() const; + + /// Get the list of all joints attached to this body. + b2JointEdge* GetJointList(); + const b2JointEdge* GetJointList() const; + + /// Get the list of all contacts attached to this body. + /// @warning this list changes during the time step and you may + /// miss some collisions if you don't use b2ContactListener. + b2ContactEdge* GetContactList(); + const b2ContactEdge* GetContactList() const; + + /// Get the next body in the world's body list. + b2Body* GetNext(); + const b2Body* GetNext() const; + + /// Get the user data pointer that was provided in the body definition. + void* GetUserData() const; + + /// Set the user data. Use this to store your application specific data. + void SetUserData(void* data); + + /// Get the parent world of this body. + b2World* GetWorld(); + const b2World* GetWorld() const; + +private: + + friend class b2World; + friend class b2Island; + friend class b2ContactManager; + friend class b2ContactSolver; + friend class b2TOISolver; + + friend class b2DistanceJoint; + friend class b2GearJoint; + friend class b2LineJoint; + friend class b2MouseJoint; + friend class b2PrismaticJoint; + friend class b2PulleyJoint; + friend class b2RevoluteJoint; + friend class b2WeldJoint; + friend class b2FrictionJoint; + + // m_flags + enum + { + e_islandFlag = 0x0001, + e_awakeFlag = 0x0002, + e_autoSleepFlag = 0x0004, + e_bulletFlag = 0x0008, + e_fixedRotationFlag = 0x0010, + e_activeFlag = 0x0020, + e_toiFlag = 0x0040, + }; + + b2Body(const b2BodyDef* bd, b2World* world); + ~b2Body(); + + void SynchronizeFixtures(); + void SynchronizeTransform(); + + // This is used to prevent connected bodies from colliding. + // It may lie, depending on the collideConnected flag. + bool ShouldCollide(const b2Body* other) const; + + void Advance(float32 t); + + b2BodyType m_type; + + uint16 m_flags; + + int32 m_islandIndex; + + b2Transform m_xf; // the body origin transform + b2Sweep m_sweep; // the swept motion for CCD + + b2Vec2 m_linearVelocity; + float32 m_angularVelocity; + + b2Vec2 m_force; + float32 m_torque; + + b2World* m_world; + b2Body* m_prev; + b2Body* m_next; + + b2Fixture* m_fixtureList; + int32 m_fixtureCount; + + b2JointEdge* m_jointList; + b2ContactEdge* m_contactList; + + float32 m_mass, m_invMass; + + // Rotational inertia about the center of mass. + float32 m_I, m_invI; + + float32 m_linearDamping; + float32 m_angularDamping; + + float32 m_sleepTime; + + void* m_userData; +}; + +inline b2BodyType b2Body::GetType() const +{ + return m_type; +} + +inline const b2Transform& b2Body::GetTransform() const +{ + return m_xf; +} + +inline const b2Vec2& b2Body::GetPosition() const +{ + return m_xf.position; +} + +inline float32 b2Body::GetAngle() const +{ + return m_sweep.a; +} + +inline const b2Vec2& b2Body::GetWorldCenter() const +{ + return m_sweep.c; +} + +inline const b2Vec2& b2Body::GetLocalCenter() const +{ + return m_sweep.localCenter; +} + +inline void b2Body::SetLinearVelocity(const b2Vec2& v) +{ + if (m_type == b2_staticBody) + { + return; + } + + if (b2Dot(v,v) > 0.0f) + { + SetAwake(true); + } + + m_linearVelocity = v; +} + +inline b2Vec2 b2Body::GetLinearVelocity() const +{ + return m_linearVelocity; +} + +inline void b2Body::SetAngularVelocity(float32 w) +{ + if (m_type == b2_staticBody) + { + return; + } + + if (w * w > 0.0f) + { + SetAwake(true); + } + + m_angularVelocity = w; +} + +inline float32 b2Body::GetAngularVelocity() const +{ + return m_angularVelocity; +} + +inline float32 b2Body::GetMass() const +{ + return m_mass; +} + +inline float32 b2Body::GetInertia() const +{ + return m_I + m_mass * b2Dot(m_sweep.localCenter, m_sweep.localCenter); +} + +inline void b2Body::GetMassData(b2MassData* data) const +{ + data->mass = m_mass; + data->I = m_I + m_mass * b2Dot(m_sweep.localCenter, m_sweep.localCenter); + data->center = m_sweep.localCenter; +} + +inline b2Vec2 b2Body::GetWorldPoint(const b2Vec2& localPoint) const +{ + return b2Mul(m_xf, localPoint); +} + +inline b2Vec2 b2Body::GetWorldVector(const b2Vec2& localVector) const +{ + return b2Mul(m_xf.R, localVector); +} + +inline b2Vec2 b2Body::GetLocalPoint(const b2Vec2& worldPoint) const +{ + return b2MulT(m_xf, worldPoint); +} + +inline b2Vec2 b2Body::GetLocalVector(const b2Vec2& worldVector) const +{ + return b2MulT(m_xf.R, worldVector); +} + +inline b2Vec2 b2Body::GetLinearVelocityFromWorldPoint(const b2Vec2& worldPoint) const +{ + return m_linearVelocity + b2Cross(m_angularVelocity, worldPoint - m_sweep.c); +} + +inline b2Vec2 b2Body::GetLinearVelocityFromLocalPoint(const b2Vec2& localPoint) const +{ + return GetLinearVelocityFromWorldPoint(GetWorldPoint(localPoint)); +} + +inline float32 b2Body::GetLinearDamping() const +{ + return m_linearDamping; +} + +inline void b2Body::SetLinearDamping(float32 linearDamping) +{ + m_linearDamping = linearDamping; +} + +inline float32 b2Body::GetAngularDamping() const +{ + return m_angularDamping; +} + +inline void b2Body::SetAngularDamping(float32 angularDamping) +{ + m_angularDamping = angularDamping; +} + +inline void b2Body::SetBullet(bool flag) +{ + if (flag) + { + m_flags |= e_bulletFlag; + } + else + { + m_flags &= ~e_bulletFlag; + } +} + +inline bool b2Body::IsBullet() const +{ + return (m_flags & e_bulletFlag) == e_bulletFlag; +} + +inline void b2Body::SetAwake(bool flag) +{ + if (flag) + { + if ((m_flags & e_awakeFlag) == 0) + { + m_flags |= e_awakeFlag; + m_sleepTime = 0.0f; + } + } + else + { + m_flags &= ~e_awakeFlag; + m_sleepTime = 0.0f; + m_linearVelocity.SetZero(); + m_angularVelocity = 0.0f; + m_force.SetZero(); + m_torque = 0.0f; + } +} + +inline bool b2Body::IsAwake() const +{ + return (m_flags & e_awakeFlag) == e_awakeFlag; +} + +inline bool b2Body::IsActive() const +{ + return (m_flags & e_activeFlag) == e_activeFlag; +} + +inline void b2Body::SetFixedRotation(bool flag) +{ + if (flag) + { + m_flags |= e_fixedRotationFlag; + } + else + { + m_flags &= ~e_fixedRotationFlag; + } + + ResetMassData(); +} + +inline bool b2Body::IsFixedRotation() const +{ + return (m_flags & e_fixedRotationFlag) == e_fixedRotationFlag; +} + +inline void b2Body::SetSleepingAllowed(bool flag) +{ + if (flag) + { + m_flags |= e_autoSleepFlag; + } + else + { + m_flags &= ~e_autoSleepFlag; + SetAwake(true); + } +} + +inline bool b2Body::IsSleepingAllowed() const +{ + return (m_flags & e_autoSleepFlag) == e_autoSleepFlag; +} + +inline b2Fixture* b2Body::GetFixtureList() +{ + return m_fixtureList; +} + +inline const b2Fixture* b2Body::GetFixtureList() const +{ + return m_fixtureList; +} + +inline b2JointEdge* b2Body::GetJointList() +{ + return m_jointList; +} + +inline const b2JointEdge* b2Body::GetJointList() const +{ + return m_jointList; +} + +inline b2ContactEdge* b2Body::GetContactList() +{ + return m_contactList; +} + +inline const b2ContactEdge* b2Body::GetContactList() const +{ + return m_contactList; +} + +inline b2Body* b2Body::GetNext() +{ + return m_next; +} + +inline const b2Body* b2Body::GetNext() const +{ + return m_next; +} + +inline void b2Body::SetUserData(void* data) +{ + m_userData = data; +} + +inline void* b2Body::GetUserData() const +{ + return m_userData; +} + +inline void b2Body::ApplyForce(const b2Vec2& force, const b2Vec2& point) +{ + if (m_type != b2_dynamicBody) + { + return; + } + + if (IsAwake() == false) + { + SetAwake(true); + } + + m_force += force; + m_torque += b2Cross(point - m_sweep.c, force); +} + +inline void b2Body::ApplyTorque(float32 torque) +{ + if (m_type != b2_dynamicBody) + { + return; + } + + if (IsAwake() == false) + { + SetAwake(true); + } + + m_torque += torque; +} + +inline void b2Body::ApplyLinearImpulse(const b2Vec2& impulse, const b2Vec2& point) +{ + if (m_type != b2_dynamicBody) + { + return; + } + + if (IsAwake() == false) + { + SetAwake(true); + } + m_linearVelocity += m_invMass * impulse; + m_angularVelocity += m_invI * b2Cross(point - m_sweep.c, impulse); +} + +inline void b2Body::ApplyAngularImpulse(float32 impulse) +{ + if (m_type != b2_dynamicBody) + { + return; + } + + if (IsAwake() == false) + { + SetAwake(true); + } + m_angularVelocity += m_invI * impulse; +} + +inline void b2Body::SynchronizeTransform() +{ + m_xf.R.Set(m_sweep.a); + m_xf.position = m_sweep.c - b2Mul(m_xf.R, m_sweep.localCenter); +} + +inline void b2Body::Advance(float32 t) +{ + // Advance to the new safe time. + m_sweep.Advance(t); + m_sweep.c = m_sweep.c0; + m_sweep.a = m_sweep.a0; + SynchronizeTransform(); +} + +inline b2World* b2Body::GetWorld() +{ + return m_world; +} + +inline const b2World* b2Body::GetWorld() const +{ + return m_world; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2BroadPhase.cpp b/uppsrc/plugin/box2d/b2BroadPhase.cpp new file mode 100644 index 000000000..fdc252b40 --- /dev/null +++ b/uppsrc/plugin/box2d/b2BroadPhase.cpp @@ -0,0 +1,116 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2BroadPhase.h" +#include + +b2BroadPhase::b2BroadPhase() +{ + m_proxyCount = 0; + + m_pairCapacity = 16; + m_pairCount = 0; + m_pairBuffer = (b2Pair*)b2Alloc(m_pairCapacity * sizeof(b2Pair)); + + m_moveCapacity = 16; + m_moveCount = 0; + m_moveBuffer = (int32*)b2Alloc(m_moveCapacity * sizeof(int32)); +} + +b2BroadPhase::~b2BroadPhase() +{ + b2Free(m_moveBuffer); + b2Free(m_pairBuffer); +} + +int32 b2BroadPhase::CreateProxy(const b2AABB& aabb, void* userData) +{ + int32 proxyId = m_tree.CreateProxy(aabb, userData); + ++m_proxyCount; + BufferMove(proxyId); + return proxyId; +} + +void b2BroadPhase::DestroyProxy(int32 proxyId) +{ + UnBufferMove(proxyId); + --m_proxyCount; + m_tree.DestroyProxy(proxyId); +} + +void b2BroadPhase::MoveProxy(int32 proxyId, const b2AABB& aabb, const b2Vec2& displacement) +{ + bool buffer = m_tree.MoveProxy(proxyId, aabb, displacement); + if (buffer) + { + BufferMove(proxyId); + } +} + +void b2BroadPhase::BufferMove(int32 proxyId) +{ + if (m_moveCount == m_moveCapacity) + { + int32* oldBuffer = m_moveBuffer; + m_moveCapacity *= 2; + m_moveBuffer = (int32*)b2Alloc(m_moveCapacity * sizeof(int32)); + memcpy(m_moveBuffer, oldBuffer, m_moveCount * sizeof(int32)); + b2Free(oldBuffer); + } + + m_moveBuffer[m_moveCount] = proxyId; + ++m_moveCount; +} + +void b2BroadPhase::UnBufferMove(int32 proxyId) +{ + for (int32 i = 0; i < m_moveCount; ++i) + { + if (m_moveBuffer[i] == proxyId) + { + m_moveBuffer[i] = e_nullProxy; + return; + } + } +} + +// This is called from b2DynamicTree::Query when we are gathering pairs. +bool b2BroadPhase::QueryCallback(int32 proxyId) +{ + // A proxy cannot form a pair with itself. + if (proxyId == m_queryProxyId) + { + return true; + } + + // Grow the pair buffer as needed. + if (m_pairCount == m_pairCapacity) + { + b2Pair* oldBuffer = m_pairBuffer; + m_pairCapacity *= 2; + m_pairBuffer = (b2Pair*)b2Alloc(m_pairCapacity * sizeof(b2Pair)); + memcpy(m_pairBuffer, oldBuffer, m_pairCount * sizeof(b2Pair)); + b2Free(oldBuffer); + } + + m_pairBuffer[m_pairCount].proxyIdA = b2Min(proxyId, m_queryProxyId); + m_pairBuffer[m_pairCount].proxyIdB = b2Max(proxyId, m_queryProxyId); + ++m_pairCount; + + return true; +} diff --git a/uppsrc/plugin/box2d/b2BroadPhase.h b/uppsrc/plugin/box2d/b2BroadPhase.h new file mode 100644 index 000000000..b7fb315f8 --- /dev/null +++ b/uppsrc/plugin/box2d/b2BroadPhase.h @@ -0,0 +1,229 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_BROAD_PHASE_H +#define B2_BROAD_PHASE_H + +#include "b2Settings.h" +#include "b2Collision.h" +#include "b2DynamicTree.h" +#include + +struct b2Pair +{ + int32 proxyIdA; + int32 proxyIdB; + int32 next; +}; + +/// The broad-phase is used for computing pairs and performing volume queries and ray casts. +/// This broad-phase does not persist pairs. Instead, this reports potentially new pairs. +/// It is up to the client to consume the new pairs and to track subsequent overlap. +class b2BroadPhase +{ +public: + + enum + { + e_nullProxy = -1, + }; + + b2BroadPhase(); + ~b2BroadPhase(); + + /// Create a proxy with an initial AABB. Pairs are not reported until + /// UpdatePairs is called. + int32 CreateProxy(const b2AABB& aabb, void* userData); + + /// Destroy a proxy. It is up to the client to remove any pairs. + void DestroyProxy(int32 proxyId); + + /// Call MoveProxy as many times as you like, then when you are done + /// call UpdatePairs to finalized the proxy pairs (for your time step). + void MoveProxy(int32 proxyId, const b2AABB& aabb, const b2Vec2& displacement); + + /// Get the fat AABB for a proxy. + const b2AABB& GetFatAABB(int32 proxyId) const; + + /// Get user data from a proxy. Returns NULL if the id is invalid. + void* GetUserData(int32 proxyId) const; + + /// Test overlap of fat AABBs. + bool TestOverlap(int32 proxyIdA, int32 proxyIdB) const; + + /// Get the number of proxies. + int32 GetProxyCount() const; + + /// Update the pairs. This results in pair callbacks. This can only add pairs. + template + void UpdatePairs(T* callback); + + /// Query an AABB for overlapping proxies. The callback class + /// is called for each proxy that overlaps the supplied AABB. + template + void Query(T* callback, const b2AABB& aabb) const; + + /// Ray-cast against the proxies in the tree. This relies on the callback + /// to perform a exact ray-cast in the case were the proxy contains a shape. + /// The callback also performs the any collision filtering. This has performance + /// roughly equal to k * log(n), where k is the number of collisions and n is the + /// number of proxies in the tree. + /// @param input the ray-cast input data. The ray extends from p1 to p1 + maxFraction * (p2 - p1). + /// @param callback a callback class that is called for each proxy that is hit by the ray. + template + void RayCast(T* callback, const b2RayCastInput& input) const; + + /// Compute the height of the embedded tree. + int32 ComputeHeight() const; + +private: + + friend class b2DynamicTree; + + void BufferMove(int32 proxyId); + void UnBufferMove(int32 proxyId); + + bool QueryCallback(int32 proxyId); + + b2DynamicTree m_tree; + + int32 m_proxyCount; + + int32* m_moveBuffer; + int32 m_moveCapacity; + int32 m_moveCount; + + b2Pair* m_pairBuffer; + int32 m_pairCapacity; + int32 m_pairCount; + + int32 m_queryProxyId; +}; + +/// This is used to sort pairs. +inline bool b2PairLessThan(const b2Pair& pair1, const b2Pair& pair2) +{ + if (pair1.proxyIdA < pair2.proxyIdA) + { + return true; + } + + if (pair1.proxyIdA == pair2.proxyIdA) + { + return pair1.proxyIdB < pair2.proxyIdB; + } + + return false; +} + +inline void* b2BroadPhase::GetUserData(int32 proxyId) const +{ + return m_tree.GetUserData(proxyId); +} + +inline bool b2BroadPhase::TestOverlap(int32 proxyIdA, int32 proxyIdB) const +{ + const b2AABB& aabbA = m_tree.GetFatAABB(proxyIdA); + const b2AABB& aabbB = m_tree.GetFatAABB(proxyIdB); + return b2TestOverlap(aabbA, aabbB); +} + +inline const b2AABB& b2BroadPhase::GetFatAABB(int32 proxyId) const +{ + return m_tree.GetFatAABB(proxyId); +} + +inline int32 b2BroadPhase::GetProxyCount() const +{ + return m_proxyCount; +} + +inline int32 b2BroadPhase::ComputeHeight() const +{ + return m_tree.ComputeHeight(); +} + +template +void b2BroadPhase::UpdatePairs(T* callback) +{ + // Reset pair buffer + m_pairCount = 0; + + // Perform tree queries for all moving proxies. + for (int32 i = 0; i < m_moveCount; ++i) + { + m_queryProxyId = m_moveBuffer[i]; + if (m_queryProxyId == e_nullProxy) + { + continue; + } + + // We have to query the tree with the fat AABB so that + // we don't fail to create a pair that may touch later. + const b2AABB& fatAABB = m_tree.GetFatAABB(m_queryProxyId); + + // Query tree, create pairs and add them pair buffer. + m_tree.Query(this, fatAABB); + } + + // Reset move buffer + m_moveCount = 0; + + // Sort the pair buffer to expose duplicates. + std::sort(m_pairBuffer, m_pairBuffer + m_pairCount, b2PairLessThan); + + // Send the pairs back to the client. + int32 i = 0; + while (i < m_pairCount) + { + b2Pair* primaryPair = m_pairBuffer + i; + void* userDataA = m_tree.GetUserData(primaryPair->proxyIdA); + void* userDataB = m_tree.GetUserData(primaryPair->proxyIdB); + + callback->AddPair(userDataA, userDataB); + ++i; + + // Skip any duplicate pairs. + while (i < m_pairCount) + { + b2Pair* pair = m_pairBuffer + i; + if (pair->proxyIdA != primaryPair->proxyIdA || pair->proxyIdB != primaryPair->proxyIdB) + { + break; + } + ++i; + } + } + + // Try to keep the tree balanced. + m_tree.Rebalance(4); +} + +template +inline void b2BroadPhase::Query(T* callback, const b2AABB& aabb) const +{ + m_tree.Query(callback, aabb); +} + +template +inline void b2BroadPhase::RayCast(T* callback, const b2RayCastInput& input) const +{ + m_tree.RayCast(callback, input); +} + +#endif diff --git a/uppsrc/plugin/box2d/b2CircleContact.cpp b/uppsrc/plugin/box2d/b2CircleContact.cpp new file mode 100644 index 000000000..958a0ab7c --- /dev/null +++ b/uppsrc/plugin/box2d/b2CircleContact.cpp @@ -0,0 +1,52 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2CircleContact.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2WorldCallbacks.h" +#include "b2BlockAllocator.h" +#include "b2TimeOfImpact.h" + +#include + +b2Contact* b2CircleContact::Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator) +{ + void* mem = allocator->Allocate(sizeof(b2CircleContact)); + return new (mem) b2CircleContact(fixtureA, fixtureB); +} + +void b2CircleContact::Destroy(b2Contact* contact, b2BlockAllocator* allocator) +{ + ((b2CircleContact*)contact)->~b2CircleContact(); + allocator->Free(contact, sizeof(b2CircleContact)); +} + +b2CircleContact::b2CircleContact(b2Fixture* fixtureA, b2Fixture* fixtureB) + : b2Contact(fixtureA, fixtureB) +{ + b2Assert(m_fixtureA->GetType() == b2Shape::e_circle); + b2Assert(m_fixtureB->GetType() == b2Shape::e_circle); +} + +void b2CircleContact::Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB) +{ + b2CollideCircles(manifold, + (b2CircleShape*)m_fixtureA->GetShape(), xfA, + (b2CircleShape*)m_fixtureB->GetShape(), xfB); +} diff --git a/uppsrc/plugin/box2d/b2CircleContact.h b/uppsrc/plugin/box2d/b2CircleContact.h new file mode 100644 index 000000000..f597d50f3 --- /dev/null +++ b/uppsrc/plugin/box2d/b2CircleContact.h @@ -0,0 +1,38 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_CIRCLE_CONTACT_H +#define B2_CIRCLE_CONTACT_H + +#include "b2Contact.h" + +class b2BlockAllocator; + +class b2CircleContact : public b2Contact +{ +public: + static b2Contact* Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator); + static void Destroy(b2Contact* contact, b2BlockAllocator* allocator); + + b2CircleContact(b2Fixture* fixtureA, b2Fixture* fixtureB); + ~b2CircleContact() {} + + void Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB); +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2CircleShape.cpp b/uppsrc/plugin/box2d/b2CircleShape.cpp new file mode 100644 index 000000000..0df4938ed --- /dev/null +++ b/uppsrc/plugin/box2d/b2CircleShape.cpp @@ -0,0 +1,89 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2CircleShape.h" +#include + +b2Shape* b2CircleShape::Clone(b2BlockAllocator* allocator) const +{ + void* mem = allocator->Allocate(sizeof(b2CircleShape)); + b2CircleShape* clone = new (mem) b2CircleShape; + *clone = *this; + return clone; +} + +bool b2CircleShape::TestPoint(const b2Transform& transform, const b2Vec2& p) const +{ + b2Vec2 center = transform.position + b2Mul(transform.R, m_p); + b2Vec2 d = p - center; + return b2Dot(d, d) <= m_radius * m_radius; +} + +// Collision Detection in Interactive 3D Environments by Gino van den Bergen +// From Section 3.1.2 +// x = s + a * r +// norm(x) = radius +bool b2CircleShape::RayCast(b2RayCastOutput* output, const b2RayCastInput& input, const b2Transform& transform) const +{ + b2Vec2 position = transform.position + b2Mul(transform.R, m_p); + b2Vec2 s = input.p1 - position; + float32 b = b2Dot(s, s) - m_radius * m_radius; + + // Solve quadratic equation. + b2Vec2 r = input.p2 - input.p1; + float32 c = b2Dot(s, r); + float32 rr = b2Dot(r, r); + float32 sigma = c * c - rr * b; + + // Check for negative discriminant and short segment. + if (sigma < 0.0f || rr < b2_epsilon) + { + return false; + } + + // Find the point of intersection of the line with the circle. + float32 a = -(c + b2Sqrt(sigma)); + + // Is the intersection point on the segment? + if (0.0f <= a && a <= input.maxFraction * rr) + { + a /= rr; + output->fraction = a; + output->normal = s + a * r; + output->normal.Normalize(); + return true; + } + + return false; +} + +void b2CircleShape::ComputeAABB(b2AABB* aabb, const b2Transform& transform) const +{ + b2Vec2 p = transform.position + b2Mul(transform.R, m_p); + aabb->lowerBound.Set(p.x - m_radius, p.y - m_radius); + aabb->upperBound.Set(p.x + m_radius, p.y + m_radius); +} + +void b2CircleShape::ComputeMass(b2MassData* massData, float32 density) const +{ + massData->mass = density * b2_pi * m_radius * m_radius; + massData->center = m_p; + + // inertia about the local origin + massData->I = massData->mass * (0.5f * m_radius * m_radius + b2Dot(m_p, m_p)); +} diff --git a/uppsrc/plugin/box2d/b2CircleShape.h b/uppsrc/plugin/box2d/b2CircleShape.h new file mode 100644 index 000000000..379d141d9 --- /dev/null +++ b/uppsrc/plugin/box2d/b2CircleShape.h @@ -0,0 +1,87 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_CIRCLE_SHAPE_H +#define B2_CIRCLE_SHAPE_H + +#include "b2Shape.h" + +/// A circle shape. +class b2CircleShape : public b2Shape +{ +public: + b2CircleShape(); + + /// Implement b2Shape. + b2Shape* Clone(b2BlockAllocator* allocator) const; + + /// Implement b2Shape. + bool TestPoint(const b2Transform& transform, const b2Vec2& p) const; + + /// Implement b2Shape. + bool RayCast(b2RayCastOutput* output, const b2RayCastInput& input, const b2Transform& transform) const; + + /// @see b2Shape::ComputeAABB + void ComputeAABB(b2AABB* aabb, const b2Transform& transform) const; + + /// @see b2Shape::ComputeMass + void ComputeMass(b2MassData* massData, float32 density) const; + + /// Get the supporting vertex index in the given direction. + int32 GetSupport(const b2Vec2& d) const; + + /// Get the supporting vertex in the given direction. + const b2Vec2& GetSupportVertex(const b2Vec2& d) const; + + /// Get the vertex count. + int32 GetVertexCount() const { return 1; } + + /// Get a vertex by index. Used by b2Distance. + const b2Vec2& GetVertex(int32 index) const; + + /// Position + b2Vec2 m_p; +}; + +inline b2CircleShape::b2CircleShape() +{ + m_type = e_circle; + m_radius = 0.0f; + m_p.SetZero(); +} + +inline int32 b2CircleShape::GetSupport(const b2Vec2 &d) const +{ + B2_NOT_USED(d); + return 0; +} + +inline const b2Vec2& b2CircleShape::GetSupportVertex(const b2Vec2 &d) const +{ + B2_NOT_USED(d); + return m_p; +} + +inline const b2Vec2& b2CircleShape::GetVertex(int32 index) const +{ + B2_NOT_USED(index); + b2Assert(index == 0); + return m_p; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2CollideCircle.cpp b/uppsrc/plugin/box2d/b2CollideCircle.cpp new file mode 100644 index 000000000..d0ecd3aff --- /dev/null +++ b/uppsrc/plugin/box2d/b2CollideCircle.cpp @@ -0,0 +1,154 @@ +/* +* Copyright (c) 2007-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Collision.h" +#include "b2CircleShape.h" +#include "b2PolygonShape.h" + +void b2CollideCircles( + b2Manifold* manifold, + const b2CircleShape* circleA, const b2Transform& xfA, + const b2CircleShape* circleB, const b2Transform& xfB) +{ + manifold->pointCount = 0; + + b2Vec2 pA = b2Mul(xfA, circleA->m_p); + b2Vec2 pB = b2Mul(xfB, circleB->m_p); + + b2Vec2 d = pB - pA; + float32 distSqr = b2Dot(d, d); + float32 rA = circleA->m_radius, rB = circleB->m_radius; + float32 radius = rA + rB; + if (distSqr > radius * radius) + { + return; + } + + manifold->type = b2Manifold::e_circles; + manifold->localPoint = circleA->m_p; + manifold->localNormal.SetZero(); + manifold->pointCount = 1; + + manifold->points[0].localPoint = circleB->m_p; + manifold->points[0].id.key = 0; +} + +void b2CollidePolygonAndCircle( + b2Manifold* manifold, + const b2PolygonShape* polygonA, const b2Transform& xfA, + const b2CircleShape* circleB, const b2Transform& xfB) +{ + manifold->pointCount = 0; + + // Compute circle position in the frame of the polygon. + b2Vec2 c = b2Mul(xfB, circleB->m_p); + b2Vec2 cLocal = b2MulT(xfA, c); + + // Find the min separating edge. + int32 normalIndex = 0; + float32 separation = -b2_maxFloat; + float32 radius = polygonA->m_radius + circleB->m_radius; + int32 vertexCount = polygonA->m_vertexCount; + const b2Vec2* vertices = polygonA->m_vertices; + const b2Vec2* normals = polygonA->m_normals; + + for (int32 i = 0; i < vertexCount; ++i) + { + float32 s = b2Dot(normals[i], cLocal - vertices[i]); + + if (s > radius) + { + // Early out. + return; + } + + if (s > separation) + { + separation = s; + normalIndex = i; + } + } + + // Vertices that subtend the incident face. + int32 vertIndex1 = normalIndex; + int32 vertIndex2 = vertIndex1 + 1 < vertexCount ? vertIndex1 + 1 : 0; + b2Vec2 v1 = vertices[vertIndex1]; + b2Vec2 v2 = vertices[vertIndex2]; + + // If the center is inside the polygon ... + if (separation < b2_epsilon) + { + manifold->pointCount = 1; + manifold->type = b2Manifold::e_faceA; + manifold->localNormal = normals[normalIndex]; + manifold->localPoint = 0.5f * (v1 + v2); + manifold->points[0].localPoint = circleB->m_p; + manifold->points[0].id.key = 0; + return; + } + + // Compute barycentric coordinates + float32 u1 = b2Dot(cLocal - v1, v2 - v1); + float32 u2 = b2Dot(cLocal - v2, v1 - v2); + if (u1 <= 0.0f) + { + if (b2DistanceSquared(cLocal, v1) > radius * radius) + { + return; + } + + manifold->pointCount = 1; + manifold->type = b2Manifold::e_faceA; + manifold->localNormal = cLocal - v1; + manifold->localNormal.Normalize(); + manifold->localPoint = v1; + manifold->points[0].localPoint = circleB->m_p; + manifold->points[0].id.key = 0; + } + else if (u2 <= 0.0f) + { + if (b2DistanceSquared(cLocal, v2) > radius * radius) + { + return; + } + + manifold->pointCount = 1; + manifold->type = b2Manifold::e_faceA; + manifold->localNormal = cLocal - v2; + manifold->localNormal.Normalize(); + manifold->localPoint = v2; + manifold->points[0].localPoint = circleB->m_p; + manifold->points[0].id.key = 0; + } + else + { + b2Vec2 faceCenter = 0.5f * (v1 + v2); + float32 separation = b2Dot(cLocal - faceCenter, normals[vertIndex1]); + if (separation > radius) + { + return; + } + + manifold->pointCount = 1; + manifold->type = b2Manifold::e_faceA; + manifold->localNormal = normals[vertIndex1]; + manifold->localPoint = faceCenter; + manifold->points[0].localPoint = circleB->m_p; + manifold->points[0].id.key = 0; + } +} diff --git a/uppsrc/plugin/box2d/b2CollidePolygon.cpp b/uppsrc/plugin/box2d/b2CollidePolygon.cpp new file mode 100644 index 000000000..2879a4646 --- /dev/null +++ b/uppsrc/plugin/box2d/b2CollidePolygon.cpp @@ -0,0 +1,306 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Collision.h" +#include "b2PolygonShape.h" + +// Find the separation between poly1 and poly2 for a give edge normal on poly1. +static float32 b2EdgeSeparation(const b2PolygonShape* poly1, const b2Transform& xf1, int32 edge1, + const b2PolygonShape* poly2, const b2Transform& xf2) +{ + int32 count1 = poly1->m_vertexCount; + const b2Vec2* vertices1 = poly1->m_vertices; + const b2Vec2* normals1 = poly1->m_normals; + + int32 count2 = poly2->m_vertexCount; + const b2Vec2* vertices2 = poly2->m_vertices; + + b2Assert(0 <= edge1 && edge1 < count1); + + // Convert normal from poly1's frame into poly2's frame. + b2Vec2 normal1World = b2Mul(xf1.R, normals1[edge1]); + b2Vec2 normal1 = b2MulT(xf2.R, normal1World); + + // Find support vertex on poly2 for -normal. + int32 index = 0; + float32 minDot = b2_maxFloat; + + for (int32 i = 0; i < count2; ++i) + { + float32 dot = b2Dot(vertices2[i], normal1); + if (dot < minDot) + { + minDot = dot; + index = i; + } + } + + b2Vec2 v1 = b2Mul(xf1, vertices1[edge1]); + b2Vec2 v2 = b2Mul(xf2, vertices2[index]); + float32 separation = b2Dot(v2 - v1, normal1World); + return separation; +} + +// Find the max separation between poly1 and poly2 using edge normals from poly1. +static float32 b2FindMaxSeparation(int32* edgeIndex, + const b2PolygonShape* poly1, const b2Transform& xf1, + const b2PolygonShape* poly2, const b2Transform& xf2) +{ + int32 count1 = poly1->m_vertexCount; + const b2Vec2* normals1 = poly1->m_normals; + + // Vector pointing from the centroid of poly1 to the centroid of poly2. + b2Vec2 d = b2Mul(xf2, poly2->m_centroid) - b2Mul(xf1, poly1->m_centroid); + b2Vec2 dLocal1 = b2MulT(xf1.R, d); + + // Find edge normal on poly1 that has the largest projection onto d. + int32 edge = 0; + float32 maxDot = -b2_maxFloat; + for (int32 i = 0; i < count1; ++i) + { + float32 dot = b2Dot(normals1[i], dLocal1); + if (dot > maxDot) + { + maxDot = dot; + edge = i; + } + } + + // Get the separation for the edge normal. + float32 s = b2EdgeSeparation(poly1, xf1, edge, poly2, xf2); + + // Check the separation for the previous edge normal. + int32 prevEdge = edge - 1 >= 0 ? edge - 1 : count1 - 1; + float32 sPrev = b2EdgeSeparation(poly1, xf1, prevEdge, poly2, xf2); + + // Check the separation for the next edge normal. + int32 nextEdge = edge + 1 < count1 ? edge + 1 : 0; + float32 sNext = b2EdgeSeparation(poly1, xf1, nextEdge, poly2, xf2); + + // Find the best edge and the search direction. + int32 bestEdge; + float32 bestSeparation; + int32 increment; + if (sPrev > s && sPrev > sNext) + { + increment = -1; + bestEdge = prevEdge; + bestSeparation = sPrev; + } + else if (sNext > s) + { + increment = 1; + bestEdge = nextEdge; + bestSeparation = sNext; + } + else + { + *edgeIndex = edge; + return s; + } + + // Perform a local search for the best edge normal. + for ( ; ; ) + { + if (increment == -1) + edge = bestEdge - 1 >= 0 ? bestEdge - 1 : count1 - 1; + else + edge = bestEdge + 1 < count1 ? bestEdge + 1 : 0; + + s = b2EdgeSeparation(poly1, xf1, edge, poly2, xf2); + + if (s > bestSeparation) + { + bestEdge = edge; + bestSeparation = s; + } + else + { + break; + } + } + + *edgeIndex = bestEdge; + return bestSeparation; +} + +static void b2FindIncidentEdge(b2ClipVertex c[2], + const b2PolygonShape* poly1, const b2Transform& xf1, int32 edge1, + const b2PolygonShape* poly2, const b2Transform& xf2) +{ + int32 count1 = poly1->m_vertexCount; + const b2Vec2* normals1 = poly1->m_normals; + + int32 count2 = poly2->m_vertexCount; + const b2Vec2* vertices2 = poly2->m_vertices; + const b2Vec2* normals2 = poly2->m_normals; + + b2Assert(0 <= edge1 && edge1 < count1); + + // Get the normal of the reference edge in poly2's frame. + b2Vec2 normal1 = b2MulT(xf2.R, b2Mul(xf1.R, normals1[edge1])); + + // Find the incident edge on poly2. + int32 index = 0; + float32 minDot = b2_maxFloat; + for (int32 i = 0; i < count2; ++i) + { + float32 dot = b2Dot(normal1, normals2[i]); + if (dot < minDot) + { + minDot = dot; + index = i; + } + } + + // Build the clip vertices for the incident edge. + int32 i1 = index; + int32 i2 = i1 + 1 < count2 ? i1 + 1 : 0; + + c[0].v = b2Mul(xf2, vertices2[i1]); + c[0].id.features.referenceEdge = (uint8)edge1; + c[0].id.features.incidentEdge = (uint8)i1; + c[0].id.features.incidentVertex = 0; + + c[1].v = b2Mul(xf2, vertices2[i2]); + c[1].id.features.referenceEdge = (uint8)edge1; + c[1].id.features.incidentEdge = (uint8)i2; + c[1].id.features.incidentVertex = 1; +} + +// Find edge normal of max separation on A - return if separating axis is found +// Find edge normal of max separation on B - return if separation axis is found +// Choose reference edge as min(minA, minB) +// Find incident edge +// Clip + +// The normal points from 1 to 2 +void b2CollidePolygons(b2Manifold* manifold, + const b2PolygonShape* polyA, const b2Transform& xfA, + const b2PolygonShape* polyB, const b2Transform& xfB) +{ + manifold->pointCount = 0; + float32 totalRadius = polyA->m_radius + polyB->m_radius; + + int32 edgeA = 0; + float32 separationA = b2FindMaxSeparation(&edgeA, polyA, xfA, polyB, xfB); + if (separationA > totalRadius) + return; + + int32 edgeB = 0; + float32 separationB = b2FindMaxSeparation(&edgeB, polyB, xfB, polyA, xfA); + if (separationB > totalRadius) + return; + + const b2PolygonShape* poly1; // reference polygon + const b2PolygonShape* poly2; // incident polygon + b2Transform xf1, xf2; + int32 edge1; // reference edge + uint8 flip; + const float32 k_relativeTol = 0.98f; + const float32 k_absoluteTol = 0.001f; + + if (separationB > k_relativeTol * separationA + k_absoluteTol) + { + poly1 = polyB; + poly2 = polyA; + xf1 = xfB; + xf2 = xfA; + edge1 = edgeB; + manifold->type = b2Manifold::e_faceB; + flip = 1; + } + else + { + poly1 = polyA; + poly2 = polyB; + xf1 = xfA; + xf2 = xfB; + edge1 = edgeA; + manifold->type = b2Manifold::e_faceA; + flip = 0; + } + + b2ClipVertex incidentEdge[2]; + b2FindIncidentEdge(incidentEdge, poly1, xf1, edge1, poly2, xf2); + + int32 count1 = poly1->m_vertexCount; + const b2Vec2* vertices1 = poly1->m_vertices; + + b2Vec2 v11 = vertices1[edge1]; + b2Vec2 v12 = edge1 + 1 < count1 ? vertices1[edge1+1] : vertices1[0]; + + b2Vec2 localTangent = v12 - v11; + localTangent.Normalize(); + + b2Vec2 localNormal = b2Cross(localTangent, 1.0f); + b2Vec2 planePoint = 0.5f * (v11 + v12); + + b2Vec2 tangent = b2Mul(xf1.R, localTangent); + b2Vec2 normal = b2Cross(tangent, 1.0f); + + v11 = b2Mul(xf1, v11); + v12 = b2Mul(xf1, v12); + + // Face offset. + float32 frontOffset = b2Dot(normal, v11); + + // Side offsets, extended by polytope skin thickness. + float32 sideOffset1 = -b2Dot(tangent, v11) + totalRadius; + float32 sideOffset2 = b2Dot(tangent, v12) + totalRadius; + + // Clip incident edge against extruded edge1 side edges. + b2ClipVertex clipPoints1[2]; + b2ClipVertex clipPoints2[2]; + int np; + + // Clip to box side 1 + np = b2ClipSegmentToLine(clipPoints1, incidentEdge, -tangent, sideOffset1); + + if (np < 2) + return; + + // Clip to negative box side 1 + np = b2ClipSegmentToLine(clipPoints2, clipPoints1, tangent, sideOffset2); + + if (np < 2) + { + return; + } + + // Now clipPoints2 contains the clipped points. + manifold->localNormal = localNormal; + manifold->localPoint = planePoint; + + int32 pointCount = 0; + for (int32 i = 0; i < b2_maxManifoldPoints; ++i) + { + float32 separation = b2Dot(normal, clipPoints2[i].v) - frontOffset; + + if (separation <= totalRadius) + { + b2ManifoldPoint* cp = manifold->points + pointCount; + cp->localPoint = b2MulT(xf2, clipPoints2[i].v); + cp->id = clipPoints2[i].id; + cp->id.features.flip = flip; + ++pointCount; + } + } + + manifold->pointCount = pointCount; +} diff --git a/uppsrc/plugin/box2d/b2Collision.cpp b/uppsrc/plugin/box2d/b2Collision.cpp new file mode 100644 index 000000000..95a5c0859 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Collision.cpp @@ -0,0 +1,250 @@ +/* +* Copyright (c) 2007-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Collision.h" +#include "b2Distance.h" + +void b2WorldManifold::Initialize(const b2Manifold* manifold, + const b2Transform& xfA, float32 radiusA, + const b2Transform& xfB, float32 radiusB) +{ + if (manifold->pointCount == 0) + { + return; + } + + switch (manifold->type) + { + case b2Manifold::e_circles: + { + normal.Set(1.0f, 0.0f); + b2Vec2 pointA = b2Mul(xfA, manifold->localPoint); + b2Vec2 pointB = b2Mul(xfB, manifold->points[0].localPoint); + if (b2DistanceSquared(pointA, pointB) > b2_epsilon * b2_epsilon) + { + normal = pointB - pointA; + normal.Normalize(); + } + + b2Vec2 cA = pointA + radiusA * normal; + b2Vec2 cB = pointB - radiusB * normal; + points[0] = 0.5f * (cA + cB); + } + break; + + case b2Manifold::e_faceA: + { + normal = b2Mul(xfA.R, manifold->localNormal); + b2Vec2 planePoint = b2Mul(xfA, manifold->localPoint); + + for (int32 i = 0; i < manifold->pointCount; ++i) + { + b2Vec2 clipPoint = b2Mul(xfB, manifold->points[i].localPoint); + b2Vec2 cA = clipPoint + (radiusA - b2Dot(clipPoint - planePoint, normal)) * normal; + b2Vec2 cB = clipPoint - radiusB * normal; + points[i] = 0.5f * (cA + cB); + } + } + break; + + case b2Manifold::e_faceB: + { + normal = b2Mul(xfB.R, manifold->localNormal); + b2Vec2 planePoint = b2Mul(xfB, manifold->localPoint); + + for (int32 i = 0; i < manifold->pointCount; ++i) + { + b2Vec2 clipPoint = b2Mul(xfA, manifold->points[i].localPoint); + b2Vec2 cB = clipPoint + (radiusB - b2Dot(clipPoint - planePoint, normal)) * normal; + b2Vec2 cA = clipPoint - radiusA * normal; + points[i] = 0.5f * (cA + cB); + } + + // Ensure normal points from A to B. + normal = -normal; + } + break; + } +} + +void b2GetPointStates(b2PointState state1[b2_maxManifoldPoints], b2PointState state2[b2_maxManifoldPoints], + const b2Manifold* manifold1, const b2Manifold* manifold2) +{ + for (int32 i = 0; i < b2_maxManifoldPoints; ++i) + { + state1[i] = b2_nullState; + state2[i] = b2_nullState; + } + + // Detect persists and removes. + for (int32 i = 0; i < manifold1->pointCount; ++i) + { + b2ContactID id = manifold1->points[i].id; + + state1[i] = b2_removeState; + + for (int32 j = 0; j < manifold2->pointCount; ++j) + { + if (manifold2->points[j].id.key == id.key) + { + state1[i] = b2_persistState; + break; + } + } + } + + // Detect persists and adds. + for (int32 i = 0; i < manifold2->pointCount; ++i) + { + b2ContactID id = manifold2->points[i].id; + + state2[i] = b2_addState; + + for (int32 j = 0; j < manifold1->pointCount; ++j) + { + if (manifold1->points[j].id.key == id.key) + { + state2[i] = b2_persistState; + break; + } + } + } +} + +// From Real-time Collision Detection, p179. +bool b2AABB::RayCast(b2RayCastOutput* output, const b2RayCastInput& input) const +{ + float32 tmin = -b2_maxFloat; + float32 tmax = b2_maxFloat; + + b2Vec2 p = input.p1; + b2Vec2 d = input.p2 - input.p1; + b2Vec2 absD = b2Abs(d); + + b2Vec2 normal; + + for (int32 i = 0; i < 2; ++i) + { + if (absD(i) < b2_epsilon) + { + // Parallel. + if (p(i) < lowerBound(i) || upperBound(i) < p(i)) + { + return false; + } + } + else + { + float32 inv_d = 1.0f / d(i); + float32 t1 = (lowerBound(i) - p(i)) * inv_d; + float32 t2 = (upperBound(i) - p(i)) * inv_d; + + // Sign of the normal vector. + float32 s = -1.0f; + + if (t1 > t2) + { + b2Swap(t1, t2); + s = 1.0f; + } + + // Push the min up + if (t1 > tmin) + { + normal.SetZero(); + normal(i) = s; + tmin = t1; + } + + // Pull the max down + tmax = b2Min(tmax, t2); + + if (tmin > tmax) + { + return false; + } + } + } + + // Does the ray start inside the box? + // Does the ray intersect beyond the max fraction? + if (tmin < 0.0f || input.maxFraction < tmin) + { + return false; + } + + // Intersection. + output->fraction = tmin; + output->normal = normal; + return true; +} + +// Sutherland-Hodgman clipping. +int32 b2ClipSegmentToLine(b2ClipVertex vOut[2], const b2ClipVertex vIn[2], + const b2Vec2& normal, float32 offset) +{ + // Start with no output points + int32 numOut = 0; + + // Calculate the distance of end points to the line + float32 distance0 = b2Dot(normal, vIn[0].v) - offset; + float32 distance1 = b2Dot(normal, vIn[1].v) - offset; + + // If the points are behind the plane + if (distance0 <= 0.0f) vOut[numOut++] = vIn[0]; + if (distance1 <= 0.0f) vOut[numOut++] = vIn[1]; + + // If the points are on different sides of the plane + if (distance0 * distance1 < 0.0f) + { + // Find intersection point of edge and plane + float32 interp = distance0 / (distance0 - distance1); + vOut[numOut].v = vIn[0].v + interp * (vIn[1].v - vIn[0].v); + if (distance0 > 0.0f) + { + vOut[numOut].id = vIn[0].id; + } + else + { + vOut[numOut].id = vIn[1].id; + } + ++numOut; + } + + return numOut; +} + +bool b2TestOverlap(const b2Shape* shapeA, const b2Shape* shapeB, + const b2Transform& xfA, const b2Transform& xfB) +{ + b2DistanceInput input; + input.proxyA.Set(shapeA); + input.proxyB.Set(shapeB); + input.transformA = xfA; + input.transformB = xfB; + input.useRadii = true; + + b2SimplexCache cache; + cache.count = 0; + + b2DistanceOutput output; + + b2Distance(&output, &cache, &input); + + return output.distance < 10.0f * b2_epsilon; +} diff --git a/uppsrc/plugin/box2d/b2Collision.h b/uppsrc/plugin/box2d/b2Collision.h new file mode 100644 index 000000000..99c2b8384 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Collision.h @@ -0,0 +1,240 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_COLLISION_H +#define B2_COLLISION_H + +#include "b2Math.h" +#include + +/// @file +/// Structures and functions used for computing contact points, distance +/// queries, and TOI queries. + +class b2Shape; +class b2CircleShape; +class b2PolygonShape; + +const uint8 b2_nullFeature = UCHAR_MAX; + +/// Contact ids to facilitate warm starting. +union b2ContactID +{ + /// The features that intersect to form the contact point + struct Features + { + uint8 referenceEdge; ///< The edge that defines the outward contact normal. + uint8 incidentEdge; ///< The edge most anti-parallel to the reference edge. + uint8 incidentVertex; ///< The vertex (0 or 1) on the incident edge that was clipped. + uint8 flip; ///< A value of 1 indicates that the reference edge is on shape2. + } features; + uint32 key; ///< Used to quickly compare contact ids. +}; + +/// A manifold point is a contact point belonging to a contact +/// manifold. It holds details related to the geometry and dynamics +/// of the contact points. +/// The local point usage depends on the manifold type: +/// -e_circles: the local center of circleB +/// -e_faceA: the local center of cirlceB or the clip point of polygonB +/// -e_faceB: the clip point of polygonA +/// This structure is stored across time steps, so we keep it small. +/// Note: the impulses are used for internal caching and may not +/// provide reliable contact forces, especially for high speed collisions. +struct b2ManifoldPoint +{ + b2Vec2 localPoint; ///< usage depends on manifold type + float32 normalImpulse; ///< the non-penetration impulse + float32 tangentImpulse; ///< the friction impulse + b2ContactID id; ///< uniquely identifies a contact point between two shapes +}; + +/// A manifold for two touching convex shapes. +/// Box2D supports multiple types of contact: +/// - clip point versus plane with radius +/// - point versus point with radius (circles) +/// The local point usage depends on the manifold type: +/// -e_circles: the local center of circleA +/// -e_faceA: the center of faceA +/// -e_faceB: the center of faceB +/// Similarly the local normal usage: +/// -e_circles: not used +/// -e_faceA: the normal on polygonA +/// -e_faceB: the normal on polygonB +/// We store contacts in this way so that position correction can +/// account for movement, which is critical for continuous physics. +/// All contact scenarios must be expressed in one of these types. +/// This structure is stored across time steps, so we keep it small. +struct b2Manifold +{ + enum Type + { + e_circles, + e_faceA, + e_faceB + }; + + b2ManifoldPoint points[b2_maxManifoldPoints]; ///< the points of contact + b2Vec2 localNormal; ///< not use for Type::e_points + b2Vec2 localPoint; ///< usage depends on manifold type + Type type; + int32 pointCount; ///< the number of manifold points +}; + +/// This is used to compute the current state of a contact manifold. +struct b2WorldManifold +{ + /// Evaluate the manifold with supplied transforms. This assumes + /// modest motion from the original state. This does not change the + /// point count, impulses, etc. The radii must come from the shapes + /// that generated the manifold. + void Initialize(const b2Manifold* manifold, + const b2Transform& xfA, float32 radiusA, + const b2Transform& xfB, float32 radiusB); + + b2Vec2 normal; ///< world vector pointing from A to B + b2Vec2 points[b2_maxManifoldPoints]; ///< world contact point (point of intersection) +}; + +/// This is used for determining the state of contact points. +enum b2PointState +{ + b2_nullState, ///< point does not exist + b2_addState, ///< point was added in the update + b2_persistState, ///< point persisted across the update + b2_removeState ///< point was removed in the update +}; + +/// Compute the point states given two manifolds. The states pertain to the transition from manifold1 +/// to manifold2. So state1 is either persist or remove while state2 is either add or persist. +void b2GetPointStates(b2PointState state1[b2_maxManifoldPoints], b2PointState state2[b2_maxManifoldPoints], + const b2Manifold* manifold1, const b2Manifold* manifold2); + +/// Used for computing contact manifolds. +struct b2ClipVertex +{ + b2Vec2 v; + b2ContactID id; +}; + +/// Ray-cast input data. The ray extends from p1 to p1 + maxFraction * (p2 - p1). +struct b2RayCastInput +{ + b2Vec2 p1, p2; + float32 maxFraction; +}; + +/// Ray-cast output data. The ray hits at p1 + fraction * (p2 - p1), where p1 and p2 +/// come from b2RayCastInput. +struct b2RayCastOutput +{ + b2Vec2 normal; + float32 fraction; +}; + +/// An axis aligned bounding box. +struct b2AABB +{ + /// Verify that the bounds are sorted. + bool IsValid() const; + + /// Get the center of the AABB. + b2Vec2 GetCenter() const + { + return 0.5f * (lowerBound + upperBound); + } + + /// Get the extents of the AABB (half-widths). + b2Vec2 GetExtents() const + { + return 0.5f * (upperBound - lowerBound); + } + + /// Combine two AABBs into this one. + void Combine(const b2AABB& aabb1, const b2AABB& aabb2) + { + lowerBound = b2Min(aabb1.lowerBound, aabb2.lowerBound); + upperBound = b2Max(aabb1.upperBound, aabb2.upperBound); + } + + /// Does this aabb contain the provided AABB. + bool Contains(const b2AABB& aabb) const + { + bool result = true; + result = result && lowerBound.x <= aabb.lowerBound.x; + result = result && lowerBound.y <= aabb.lowerBound.y; + result = result && aabb.upperBound.x <= upperBound.x; + result = result && aabb.upperBound.y <= upperBound.y; + return result; + } + + bool RayCast(b2RayCastOutput* output, const b2RayCastInput& input) const; + + b2Vec2 lowerBound; ///< the lower vertex + b2Vec2 upperBound; ///< the upper vertex +}; + +/// Compute the collision manifold between two circles. +void b2CollideCircles(b2Manifold* manifold, + const b2CircleShape* circle1, const b2Transform& xf1, + const b2CircleShape* circle2, const b2Transform& xf2); + +/// Compute the collision manifold between a polygon and a circle. +void b2CollidePolygonAndCircle(b2Manifold* manifold, + const b2PolygonShape* polygon, const b2Transform& xf1, + const b2CircleShape* circle, const b2Transform& xf2); + +/// Compute the collision manifold between two polygons. +void b2CollidePolygons(b2Manifold* manifold, + const b2PolygonShape* polygon1, const b2Transform& xf1, + const b2PolygonShape* polygon2, const b2Transform& xf2); + +/// Clipping for contact manifolds. +int32 b2ClipSegmentToLine(b2ClipVertex vOut[2], const b2ClipVertex vIn[2], + const b2Vec2& normal, float32 offset); + +/// Determine if two generic shapes overlap. +bool b2TestOverlap(const b2Shape* shapeA, const b2Shape* shapeB, + const b2Transform& xfA, const b2Transform& xfB); + +// ---------------- Inline Functions ------------------------------------------ + +inline bool b2AABB::IsValid() const +{ + b2Vec2 d = upperBound - lowerBound; + bool valid = d.x >= 0.0f && d.y >= 0.0f; + valid = valid && lowerBound.IsValid() && upperBound.IsValid(); + return valid; +} + +inline bool b2TestOverlap(const b2AABB& a, const b2AABB& b) +{ + b2Vec2 d1, d2; + d1 = b.lowerBound - a.upperBound; + d2 = a.lowerBound - b.upperBound; + + if (d1.x > 0.0f || d1.y > 0.0f) + return false; + + if (d2.x > 0.0f || d2.y > 0.0f) + return false; + + return true; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2Contact.cpp b/uppsrc/plugin/box2d/b2Contact.cpp new file mode 100644 index 000000000..1f237c0a8 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Contact.cpp @@ -0,0 +1,226 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Contact.h" +#include "b2CircleContact.h" +#include "b2PolygonAndCircleContact.h" +#include "b2PolygonContact.h" +#include "b2ContactSolver.h" + +#include "b2Collision.h" +#include "b2TimeOfImpact.h" +#include "b2Shape.h" +#include "b2BlockAllocator.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2World.h" + +b2ContactRegister b2Contact::s_registers[b2Shape::e_typeCount][b2Shape::e_typeCount]; +bool b2Contact::s_initialized = false; + +void b2Contact::InitializeRegisters() +{ + AddType(b2CircleContact::Create, b2CircleContact::Destroy, b2Shape::e_circle, b2Shape::e_circle); + AddType(b2PolygonAndCircleContact::Create, b2PolygonAndCircleContact::Destroy, b2Shape::e_polygon, b2Shape::e_circle); + AddType(b2PolygonContact::Create, b2PolygonContact::Destroy, b2Shape::e_polygon, b2Shape::e_polygon); +} + +void b2Contact::AddType(b2ContactCreateFcn* createFcn, b2ContactDestroyFcn* destoryFcn, + b2Shape::Type type1, b2Shape::Type type2) +{ + b2Assert(b2Shape::e_unknown < type1 && type1 < b2Shape::e_typeCount); + b2Assert(b2Shape::e_unknown < type2 && type2 < b2Shape::e_typeCount); + + s_registers[type1][type2].createFcn = createFcn; + s_registers[type1][type2].destroyFcn = destoryFcn; + s_registers[type1][type2].primary = true; + + if (type1 != type2) + { + s_registers[type2][type1].createFcn = createFcn; + s_registers[type2][type1].destroyFcn = destoryFcn; + s_registers[type2][type1].primary = false; + } +} + +b2Contact* b2Contact::Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator) +{ + if (s_initialized == false) + { + InitializeRegisters(); + s_initialized = true; + } + + b2Shape::Type type1 = fixtureA->GetType(); + b2Shape::Type type2 = fixtureB->GetType(); + + b2Assert(b2Shape::e_unknown < type1 && type1 < b2Shape::e_typeCount); + b2Assert(b2Shape::e_unknown < type2 && type2 < b2Shape::e_typeCount); + + b2ContactCreateFcn* createFcn = s_registers[type1][type2].createFcn; + if (createFcn) + { + if (s_registers[type1][type2].primary) + { + return createFcn(fixtureA, fixtureB, allocator); + } + else + { + return createFcn(fixtureB, fixtureA, allocator); + } + } + else + { + return NULL; + } +} + +void b2Contact::Destroy(b2Contact* contact, b2BlockAllocator* allocator) +{ + b2Assert(s_initialized == true); + + if (contact->m_manifold.pointCount > 0) + { + contact->GetFixtureA()->GetBody()->SetAwake(true); + contact->GetFixtureB()->GetBody()->SetAwake(true); + } + + b2Shape::Type typeA = contact->GetFixtureA()->GetType(); + b2Shape::Type typeB = contact->GetFixtureB()->GetType(); + + b2Assert(b2Shape::e_unknown < typeA && typeB < b2Shape::e_typeCount); + b2Assert(b2Shape::e_unknown < typeA && typeB < b2Shape::e_typeCount); + + b2ContactDestroyFcn* destroyFcn = s_registers[typeA][typeB].destroyFcn; + destroyFcn(contact, allocator); +} + +b2Contact::b2Contact(b2Fixture* fA, b2Fixture* fB) +{ + m_flags = e_enabledFlag; + + m_fixtureA = fA; + m_fixtureB = fB; + + m_manifold.pointCount = 0; + + m_prev = NULL; + m_next = NULL; + + m_nodeA.contact = NULL; + m_nodeA.prev = NULL; + m_nodeA.next = NULL; + m_nodeA.other = NULL; + + m_nodeB.contact = NULL; + m_nodeB.prev = NULL; + m_nodeB.next = NULL; + m_nodeB.other = NULL; + + m_toiCount = 0; +} + +// Update the contact manifold and touching status. +// Note: do not assume the fixture AABBs are overlapping or are valid. +void b2Contact::Update(b2ContactListener* listener) +{ + b2Manifold oldManifold = m_manifold; + + // Re-enable this contact. + m_flags |= e_enabledFlag; + + bool touching = false; + bool wasTouching = (m_flags & e_touchingFlag) == e_touchingFlag; + + bool sensorA = m_fixtureA->IsSensor(); + bool sensorB = m_fixtureB->IsSensor(); + bool sensor = sensorA || sensorB; + + b2Body* bodyA = m_fixtureA->GetBody(); + b2Body* bodyB = m_fixtureB->GetBody(); + const b2Transform& xfA = bodyA->GetTransform(); + const b2Transform& xfB = bodyB->GetTransform(); + + // Is this contact a sensor? + if (sensor) + { + const b2Shape* shapeA = m_fixtureA->GetShape(); + const b2Shape* shapeB = m_fixtureB->GetShape(); + touching = b2TestOverlap(shapeA, shapeB, xfA, xfB); + + // Sensors don't generate manifolds. + m_manifold.pointCount = 0; + } + else + { + Evaluate(&m_manifold, xfA, xfB); + touching = m_manifold.pointCount > 0; + + // Match old contact ids to new contact ids and copy the + // stored impulses to warm start the solver. + for (int32 i = 0; i < m_manifold.pointCount; ++i) + { + b2ManifoldPoint* mp2 = m_manifold.points + i; + mp2->normalImpulse = 0.0f; + mp2->tangentImpulse = 0.0f; + b2ContactID id2 = mp2->id; + + for (int32 j = 0; j < oldManifold.pointCount; ++j) + { + b2ManifoldPoint* mp1 = oldManifold.points + j; + + if (mp1->id.key == id2.key) + { + mp2->normalImpulse = mp1->normalImpulse; + mp2->tangentImpulse = mp1->tangentImpulse; + break; + } + } + } + + if (touching != wasTouching) + { + bodyA->SetAwake(true); + bodyB->SetAwake(true); + } + } + + if (touching) + { + m_flags |= e_touchingFlag; + } + else + { + m_flags &= ~e_touchingFlag; + } + + if (wasTouching == false && touching == true && listener) + { + listener->BeginContact(this); + } + + if (wasTouching == true && touching == false && listener) + { + listener->EndContact(this); + } + + if (sensor == false && touching && listener) + { + listener->PreSolve(this, &oldManifold); + } +} diff --git a/uppsrc/plugin/box2d/b2Contact.h b/uppsrc/plugin/box2d/b2Contact.h new file mode 100644 index 000000000..dba081f8c --- /dev/null +++ b/uppsrc/plugin/box2d/b2Contact.h @@ -0,0 +1,242 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_CONTACT_H +#define B2_CONTACT_H + +#include "b2Math.h" +#include "b2Collision.h" +#include "b2Shape.h" +#include "b2Contact.h" +#include "b2Fixture.h" + +class b2Body; +class b2Contact; +class b2Fixture; +class b2World; +class b2BlockAllocator; +class b2StackAllocator; +class b2ContactListener; + +typedef b2Contact* b2ContactCreateFcn(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator); +typedef void b2ContactDestroyFcn(b2Contact* contact, b2BlockAllocator* allocator); + +struct b2ContactRegister +{ + b2ContactCreateFcn* createFcn; + b2ContactDestroyFcn* destroyFcn; + bool primary; +}; + +/// A contact edge is used to connect bodies and contacts together +/// in a contact graph where each body is a node and each contact +/// is an edge. A contact edge belongs to a doubly linked list +/// maintained in each attached body. Each contact has two contact +/// nodes, one for each attached body. +struct b2ContactEdge +{ + b2Body* other; ///< provides quick access to the other body attached. + b2Contact* contact; ///< the contact + b2ContactEdge* prev; ///< the previous contact edge in the body's contact list + b2ContactEdge* next; ///< the next contact edge in the body's contact list +}; + +/// The class manages contact between two shapes. A contact exists for each overlapping +/// AABB in the broad-phase (except if filtered). Therefore a contact object may exist +/// that has no contact points. +class b2Contact +{ +public: + + /// Get the contact manifold. Do not modify the manifold unless you understand the + /// internals of Box2D. + b2Manifold* GetManifold(); + const b2Manifold* GetManifold() const; + + /// Get the world manifold. + void GetWorldManifold(b2WorldManifold* worldManifold) const; + + /// Is this contact touching? + bool IsTouching() const; + + /// Enable/disable this contact. This can be used inside the pre-solve + /// contact listener. The contact is only disabled for the current + /// time step (or sub-step in continuous collisions). + void SetEnabled(bool flag); + + /// Has this contact been disabled? + bool IsEnabled() const; + + /// Get the next contact in the world's contact list. + b2Contact* GetNext(); + const b2Contact* GetNext() const; + + /// Get the first fixture in this contact. + b2Fixture* GetFixtureA(); + const b2Fixture* GetFixtureA() const; + + /// Get the second fixture in this contact. + b2Fixture* GetFixtureB(); + const b2Fixture* GetFixtureB() const; + + /// Evaluate this contact with your own manifold and transforms. + virtual void Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB) = 0; + +protected: + friend class b2ContactManager; + friend class b2World; + friend class b2ContactSolver; + friend class b2Body; + friend class b2Fixture; + + // Flags stored in m_flags + enum + { + // Used when crawling contact graph when forming islands. + e_islandFlag = 0x0001, + + // Set when the shapes are touching. + e_touchingFlag = 0x0002, + + // This contact can be disabled (by user) + e_enabledFlag = 0x0004, + + // This contact needs filtering because a fixture filter was changed. + e_filterFlag = 0x0008, + + // This bullet contact had a TOI event + e_bulletHitFlag = 0x0010, + + }; + + /// Flag this contact for filtering. Filtering will occur the next time step. + void FlagForFiltering(); + + static void AddType(b2ContactCreateFcn* createFcn, b2ContactDestroyFcn* destroyFcn, + b2Shape::Type typeA, b2Shape::Type typeB); + static void InitializeRegisters(); + static b2Contact* Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator); + static void Destroy(b2Contact* contact, b2Shape::Type typeA, b2Shape::Type typeB, b2BlockAllocator* allocator); + static void Destroy(b2Contact* contact, b2BlockAllocator* allocator); + + b2Contact() : m_fixtureA(NULL), m_fixtureB(NULL) {} + b2Contact(b2Fixture* fixtureA, b2Fixture* fixtureB); + virtual ~b2Contact() {} + + void Update(b2ContactListener* listener); + + static b2ContactRegister s_registers[b2Shape::e_typeCount][b2Shape::e_typeCount]; + static bool s_initialized; + + uint32 m_flags; + + // World pool and list pointers. + b2Contact* m_prev; + b2Contact* m_next; + + // Nodes for connecting bodies. + b2ContactEdge m_nodeA; + b2ContactEdge m_nodeB; + + b2Fixture* m_fixtureA; + b2Fixture* m_fixtureB; + + b2Manifold m_manifold; + + int32 m_toiCount; +// float32 m_toi; +}; + +inline b2Manifold* b2Contact::GetManifold() +{ + return &m_manifold; +} + +inline const b2Manifold* b2Contact::GetManifold() const +{ + return &m_manifold; +} + +inline void b2Contact::GetWorldManifold(b2WorldManifold* worldManifold) const +{ + const b2Body* bodyA = m_fixtureA->GetBody(); + const b2Body* bodyB = m_fixtureB->GetBody(); + const b2Shape* shapeA = m_fixtureA->GetShape(); + const b2Shape* shapeB = m_fixtureB->GetShape(); + + worldManifold->Initialize(&m_manifold, bodyA->GetTransform(), shapeA->m_radius, bodyB->GetTransform(), shapeB->m_radius); +} + +inline void b2Contact::SetEnabled(bool flag) +{ + if (flag) + { + m_flags |= e_enabledFlag; + } + else + { + m_flags &= ~e_enabledFlag; + } +} + +inline bool b2Contact::IsEnabled() const +{ + return (m_flags & e_enabledFlag) == e_enabledFlag; +} + +inline bool b2Contact::IsTouching() const +{ + return (m_flags & e_touchingFlag) == e_touchingFlag; +} + +inline b2Contact* b2Contact::GetNext() +{ + return m_next; +} + +inline const b2Contact* b2Contact::GetNext() const +{ + return m_next; +} + +inline b2Fixture* b2Contact::GetFixtureA() +{ + return m_fixtureA; +} + +inline const b2Fixture* b2Contact::GetFixtureA() const +{ + return m_fixtureA; +} + +inline b2Fixture* b2Contact::GetFixtureB() +{ + return m_fixtureB; +} + +inline const b2Fixture* b2Contact::GetFixtureB() const +{ + return m_fixtureB; +} + +inline void b2Contact::FlagForFiltering() +{ + m_flags |= e_filterFlag; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2ContactManager.cpp b/uppsrc/plugin/box2d/b2ContactManager.cpp new file mode 100644 index 000000000..b232a11ca --- /dev/null +++ b/uppsrc/plugin/box2d/b2ContactManager.cpp @@ -0,0 +1,266 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2ContactManager.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2WorldCallbacks.h" +#include "b2Contact.h" + +b2ContactFilter b2_defaultFilter; +b2ContactListener b2_defaultListener; + +b2ContactManager::b2ContactManager() +{ + m_contactList = NULL; + m_contactCount = 0; + m_contactFilter = &b2_defaultFilter; + m_contactListener = &b2_defaultListener; + m_allocator = NULL; +} + +void b2ContactManager::Destroy(b2Contact* c) +{ + b2Fixture* fixtureA = c->GetFixtureA(); + b2Fixture* fixtureB = c->GetFixtureB(); + b2Body* bodyA = fixtureA->GetBody(); + b2Body* bodyB = fixtureB->GetBody(); + + if (m_contactListener && c->IsTouching()) + { + m_contactListener->EndContact(c); + } + + // Remove from the world. + if (c->m_prev) + { + c->m_prev->m_next = c->m_next; + } + + if (c->m_next) + { + c->m_next->m_prev = c->m_prev; + } + + if (c == m_contactList) + { + m_contactList = c->m_next; + } + + // Remove from body 1 + if (c->m_nodeA.prev) + { + c->m_nodeA.prev->next = c->m_nodeA.next; + } + + if (c->m_nodeA.next) + { + c->m_nodeA.next->prev = c->m_nodeA.prev; + } + + if (&c->m_nodeA == bodyA->m_contactList) + { + bodyA->m_contactList = c->m_nodeA.next; + } + + // Remove from body 2 + if (c->m_nodeB.prev) + { + c->m_nodeB.prev->next = c->m_nodeB.next; + } + + if (c->m_nodeB.next) + { + c->m_nodeB.next->prev = c->m_nodeB.prev; + } + + if (&c->m_nodeB == bodyB->m_contactList) + { + bodyB->m_contactList = c->m_nodeB.next; + } + + // Call the factory. + b2Contact::Destroy(c, m_allocator); + --m_contactCount; +} + +// This is the top level collision call for the time step. Here +// all the narrow phase collision is processed for the world +// contact list. +void b2ContactManager::Collide() +{ + // Update awake contacts. + b2Contact* c = m_contactList; + while (c) + { + b2Fixture* fixtureA = c->GetFixtureA(); + b2Fixture* fixtureB = c->GetFixtureB(); + b2Body* bodyA = fixtureA->GetBody(); + b2Body* bodyB = fixtureB->GetBody(); + + if (bodyA->IsAwake() == false && bodyB->IsAwake() == false) + { + c = c->GetNext(); + continue; + } + + // Is this contact flagged for filtering? + if (c->m_flags & b2Contact::e_filterFlag) + { + // Should these bodies collide? + if (bodyB->ShouldCollide(bodyA) == false) + { + b2Contact* cNuke = c; + c = cNuke->GetNext(); + Destroy(cNuke); + continue; + } + + // Check user filtering. + if (m_contactFilter && m_contactFilter->ShouldCollide(fixtureA, fixtureB) == false) + { + b2Contact* cNuke = c; + c = cNuke->GetNext(); + Destroy(cNuke); + continue; + } + + // Clear the filtering flag. + c->m_flags &= ~b2Contact::e_filterFlag; + } + + int32 proxyIdA = fixtureA->m_proxyId; + int32 proxyIdB = fixtureB->m_proxyId; + bool overlap = m_broadPhase.TestOverlap(proxyIdA, proxyIdB); + + // Here we destroy contacts that cease to overlap in the broad-phase. + if (overlap == false) + { + b2Contact* cNuke = c; + c = cNuke->GetNext(); + Destroy(cNuke); + continue; + } + + // The contact persists. + c->Update(m_contactListener); + c = c->GetNext(); + } +} + +void b2ContactManager::FindNewContacts() +{ + m_broadPhase.UpdatePairs(this); +} + +void b2ContactManager::AddPair(void* proxyUserDataA, void* proxyUserDataB) +{ + b2Fixture* fixtureA = (b2Fixture*)proxyUserDataA; + b2Fixture* fixtureB = (b2Fixture*)proxyUserDataB; + + b2Body* bodyA = fixtureA->GetBody(); + b2Body* bodyB = fixtureB->GetBody(); + + // Are the fixtures on the same body? + if (bodyA == bodyB) + { + return; + } + + // Does a contact already exist? + b2ContactEdge* edge = bodyB->GetContactList(); + while (edge) + { + if (edge->other == bodyA) + { + b2Fixture* fA = edge->contact->GetFixtureA(); + b2Fixture* fB = edge->contact->GetFixtureB(); + if (fA == fixtureA && fB == fixtureB) + { + // A contact already exists. + return; + } + + if (fA == fixtureB && fB == fixtureA) + { + // A contact already exists. + return; + } + } + + edge = edge->next; + } + + // Does a joint override collision? Is at least one body dynamic? + if (bodyB->ShouldCollide(bodyA) == false) + { + return; + } + + // Check user filtering. + if (m_contactFilter && m_contactFilter->ShouldCollide(fixtureA, fixtureB) == false) + { + return; + } + + // Call the factory. + b2Contact* c = b2Contact::Create(fixtureA, fixtureB, m_allocator); + + // Contact creation may swap fixtures. + fixtureA = c->GetFixtureA(); + fixtureB = c->GetFixtureB(); + bodyA = fixtureA->GetBody(); + bodyB = fixtureB->GetBody(); + + // Insert into the world. + c->m_prev = NULL; + c->m_next = m_contactList; + if (m_contactList != NULL) + { + m_contactList->m_prev = c; + } + m_contactList = c; + + // Connect to island graph. + + // Connect to body A + c->m_nodeA.contact = c; + c->m_nodeA.other = bodyB; + + c->m_nodeA.prev = NULL; + c->m_nodeA.next = bodyA->m_contactList; + if (bodyA->m_contactList != NULL) + { + bodyA->m_contactList->prev = &c->m_nodeA; + } + bodyA->m_contactList = &c->m_nodeA; + + // Connect to body B + c->m_nodeB.contact = c; + c->m_nodeB.other = bodyA; + + c->m_nodeB.prev = NULL; + c->m_nodeB.next = bodyB->m_contactList; + if (bodyB->m_contactList != NULL) + { + bodyB->m_contactList->prev = &c->m_nodeB; + } + bodyB->m_contactList = &c->m_nodeB; + + ++m_contactCount; +} diff --git a/uppsrc/plugin/box2d/b2ContactManager.h b/uppsrc/plugin/box2d/b2ContactManager.h new file mode 100644 index 000000000..275cdaf84 --- /dev/null +++ b/uppsrc/plugin/box2d/b2ContactManager.h @@ -0,0 +1,52 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_CONTACT_MANAGER_H +#define B2_CONTACT_MANAGER_H + +#include "b2BroadPhase.h" + +class b2Contact; +class b2ContactFilter; +class b2ContactListener; +class b2BlockAllocator; + +// Delegate of b2World. +class b2ContactManager +{ +public: + b2ContactManager(); + + // Broad-phase callback. + void AddPair(void* proxyUserDataA, void* proxyUserDataB); + + void FindNewContacts(); + + void Destroy(b2Contact* c); + + void Collide(); + + b2BroadPhase m_broadPhase; + b2Contact* m_contactList; + int32 m_contactCount; + b2ContactFilter* m_contactFilter; + b2ContactListener* m_contactListener; + b2BlockAllocator* m_allocator; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2ContactSolver.cpp b/uppsrc/plugin/box2d/b2ContactSolver.cpp new file mode 100644 index 000000000..4d920d89b --- /dev/null +++ b/uppsrc/plugin/box2d/b2ContactSolver.cpp @@ -0,0 +1,623 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2ContactSolver.h" +#include "b2Contact.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2World.h" +#include "b2StackAllocator.h" + +#define B2_DEBUG_SOLVER 0 + +b2ContactSolver::b2ContactSolver(b2Contact** contacts, int32 contactCount, + b2StackAllocator* allocator, float32 impulseRatio) +{ + m_allocator = allocator; + + m_constraintCount = contactCount; + m_constraints = (b2ContactConstraint*)m_allocator->Allocate(m_constraintCount * sizeof(b2ContactConstraint)); + + for (int32 i = 0; i < m_constraintCount; ++i) + { + b2Contact* contact = contacts[i]; + + b2Fixture* fixtureA = contact->m_fixtureA; + b2Fixture* fixtureB = contact->m_fixtureB; + b2Shape* shapeA = fixtureA->GetShape(); + b2Shape* shapeB = fixtureB->GetShape(); + float32 radiusA = shapeA->m_radius; + float32 radiusB = shapeB->m_radius; + b2Body* bodyA = fixtureA->GetBody(); + b2Body* bodyB = fixtureB->GetBody(); + b2Manifold* manifold = contact->GetManifold(); + + float32 friction = b2MixFriction(fixtureA->GetFriction(), fixtureB->GetFriction()); + float32 restitution = b2MixRestitution(fixtureA->GetRestitution(), fixtureB->GetRestitution()); + + b2Vec2 vA = bodyA->m_linearVelocity; + b2Vec2 vB = bodyB->m_linearVelocity; + float32 wA = bodyA->m_angularVelocity; + float32 wB = bodyB->m_angularVelocity; + + b2Assert(manifold->pointCount > 0); + + b2WorldManifold worldManifold; + worldManifold.Initialize(manifold, bodyA->m_xf, radiusA, bodyB->m_xf, radiusB); + + b2ContactConstraint* cc = m_constraints + i; + cc->bodyA = bodyA; + cc->bodyB = bodyB; + cc->manifold = manifold; + cc->normal = worldManifold.normal; + cc->pointCount = manifold->pointCount; + cc->friction = friction; + + cc->localNormal = manifold->localNormal; + cc->localPoint = manifold->localPoint; + cc->radius = radiusA + radiusB; + cc->type = manifold->type; + + for (int32 j = 0; j < cc->pointCount; ++j) + { + b2ManifoldPoint* cp = manifold->points + j; + b2ContactConstraintPoint* ccp = cc->points + j; + + ccp->normalImpulse = impulseRatio * cp->normalImpulse; + ccp->tangentImpulse = impulseRatio * cp->tangentImpulse; + + ccp->localPoint = cp->localPoint; + + ccp->rA = worldManifold.points[j] - bodyA->m_sweep.c; + ccp->rB = worldManifold.points[j] - bodyB->m_sweep.c; + + float32 rnA = b2Cross(ccp->rA, cc->normal); + float32 rnB = b2Cross(ccp->rB, cc->normal); + rnA *= rnA; + rnB *= rnB; + + float32 kNormal = bodyA->m_invMass + bodyB->m_invMass + bodyA->m_invI * rnA + bodyB->m_invI * rnB; + + b2Assert(kNormal > b2_epsilon); + ccp->normalMass = 1.0f / kNormal; + + b2Vec2 tangent = b2Cross(cc->normal, 1.0f); + + float32 rtA = b2Cross(ccp->rA, tangent); + float32 rtB = b2Cross(ccp->rB, tangent); + rtA *= rtA; + rtB *= rtB; + + float32 kTangent = bodyA->m_invMass + bodyB->m_invMass + bodyA->m_invI * rtA + bodyB->m_invI * rtB; + + b2Assert(kTangent > b2_epsilon); + ccp->tangentMass = 1.0f / kTangent; + + // Setup a velocity bias for restitution. + ccp->velocityBias = 0.0f; + float32 vRel = b2Dot(cc->normal, vB + b2Cross(wB, ccp->rB) - vA - b2Cross(wA, ccp->rA)); + if (vRel < -b2_velocityThreshold) + { + ccp->velocityBias = -restitution * vRel; + } + } + + // If we have two points, then prepare the block solver. + if (cc->pointCount == 2) + { + b2ContactConstraintPoint* ccp1 = cc->points + 0; + b2ContactConstraintPoint* ccp2 = cc->points + 1; + + float32 invMassA = bodyA->m_invMass; + float32 invIA = bodyA->m_invI; + float32 invMassB = bodyB->m_invMass; + float32 invIB = bodyB->m_invI; + + float32 rn1A = b2Cross(ccp1->rA, cc->normal); + float32 rn1B = b2Cross(ccp1->rB, cc->normal); + float32 rn2A = b2Cross(ccp2->rA, cc->normal); + float32 rn2B = b2Cross(ccp2->rB, cc->normal); + + float32 k11 = invMassA + invMassB + invIA * rn1A * rn1A + invIB * rn1B * rn1B; + float32 k22 = invMassA + invMassB + invIA * rn2A * rn2A + invIB * rn2B * rn2B; + float32 k12 = invMassA + invMassB + invIA * rn1A * rn2A + invIB * rn1B * rn2B; + + // Ensure a reasonable condition number. + const float32 k_maxConditionNumber = 100.0f; + if (k11 * k11 < k_maxConditionNumber * (k11 * k22 - k12 * k12)) + { + // K is safe to invert. + cc->K.col1.Set(k11, k12); + cc->K.col2.Set(k12, k22); + cc->normalMass = cc->K.GetInverse(); + } + else + { + // The constraints are redundant, just use one. + // TODO_ERIN use deepest? + cc->pointCount = 1; + } + } + } +} + +b2ContactSolver::~b2ContactSolver() +{ + m_allocator->Free(m_constraints); +} + +void b2ContactSolver::WarmStart() +{ + // Warm start. + for (int32 i = 0; i < m_constraintCount; ++i) + { + b2ContactConstraint* c = m_constraints + i; + + b2Body* bodyA = c->bodyA; + b2Body* bodyB = c->bodyB; + float32 invMassA = bodyA->m_invMass; + float32 invIA = bodyA->m_invI; + float32 invMassB = bodyB->m_invMass; + float32 invIB = bodyB->m_invI; + b2Vec2 normal = c->normal; + b2Vec2 tangent = b2Cross(normal, 1.0f); + + for (int32 j = 0; j < c->pointCount; ++j) + { + b2ContactConstraintPoint* ccp = c->points + j; + b2Vec2 P = ccp->normalImpulse * normal + ccp->tangentImpulse * tangent; + bodyA->m_angularVelocity -= invIA * b2Cross(ccp->rA, P); + bodyA->m_linearVelocity -= invMassA * P; + bodyB->m_angularVelocity += invIB * b2Cross(ccp->rB, P); + bodyB->m_linearVelocity += invMassB * P; + } + } +} + +void b2ContactSolver::SolveVelocityConstraints() +{ + for (int32 i = 0; i < m_constraintCount; ++i) + { + b2ContactConstraint* c = m_constraints + i; + b2Body* bodyA = c->bodyA; + b2Body* bodyB = c->bodyB; + float32 wA = bodyA->m_angularVelocity; + float32 wB = bodyB->m_angularVelocity; + b2Vec2 vA = bodyA->m_linearVelocity; + b2Vec2 vB = bodyB->m_linearVelocity; + float32 invMassA = bodyA->m_invMass; + float32 invIA = bodyA->m_invI; + float32 invMassB = bodyB->m_invMass; + float32 invIB = bodyB->m_invI; + b2Vec2 normal = c->normal; + b2Vec2 tangent = b2Cross(normal, 1.0f); + float32 friction = c->friction; + + b2Assert(c->pointCount == 1 || c->pointCount == 2); + + // Solve tangent constraints + for (int32 j = 0; j < c->pointCount; ++j) + { + b2ContactConstraintPoint* ccp = c->points + j; + + // Relative velocity at contact + b2Vec2 dv = vB + b2Cross(wB, ccp->rB) - vA - b2Cross(wA, ccp->rA); + + // Compute tangent force + float32 vt = b2Dot(dv, tangent); + float32 lambda = ccp->tangentMass * (-vt); + + // b2Clamp the accumulated force + float32 maxFriction = friction * ccp->normalImpulse; + float32 newImpulse = b2Clamp(ccp->tangentImpulse + lambda, -maxFriction, maxFriction); + lambda = newImpulse - ccp->tangentImpulse; + + // Apply contact impulse + b2Vec2 P = lambda * tangent; + + vA -= invMassA * P; + wA -= invIA * b2Cross(ccp->rA, P); + + vB += invMassB * P; + wB += invIB * b2Cross(ccp->rB, P); + + ccp->tangentImpulse = newImpulse; + } + + // Solve normal constraints + if (c->pointCount == 1) + { + b2ContactConstraintPoint* ccp = c->points + 0; + + // Relative velocity at contact + b2Vec2 dv = vB + b2Cross(wB, ccp->rB) - vA - b2Cross(wA, ccp->rA); + + // Compute normal impulse + float32 vn = b2Dot(dv, normal); + float32 lambda = -ccp->normalMass * (vn - ccp->velocityBias); + + // b2Clamp the accumulated impulse + float32 newImpulse = b2Max(ccp->normalImpulse + lambda, 0.0f); + lambda = newImpulse - ccp->normalImpulse; + + // Apply contact impulse + b2Vec2 P = lambda * normal; + vA -= invMassA * P; + wA -= invIA * b2Cross(ccp->rA, P); + + vB += invMassB * P; + wB += invIB * b2Cross(ccp->rB, P); + ccp->normalImpulse = newImpulse; + } + else + { + // Block solver developed in collaboration with Dirk Gregorius (back in 01/07 on Box2D_Lite). + // Build the mini LCP for this contact patch + // + // vn = A * x + b, vn >= 0, , vn >= 0, x >= 0 and vn_i * x_i = 0 with i = 1..2 + // + // A = J * W * JT and J = ( -n, -r1 x n, n, r2 x n ) + // b = vn_0 - velocityBias + // + // The system is solved using the "Total enumeration method" (s. Murty). The complementary constraint vn_i * x_i + // implies that we must have in any solution either vn_i = 0 or x_i = 0. So for the 2D contact problem the cases + // vn1 = 0 and vn2 = 0, x1 = 0 and x2 = 0, x1 = 0 and vn2 = 0, x2 = 0 and vn1 = 0 need to be tested. The first valid + // solution that satisfies the problem is chosen. + // + // In order to account of the accumulated impulse 'a' (because of the iterative nature of the solver which only requires + // that the accumulated impulse is clamped and not the incremental impulse) we change the impulse variable (x_i). + // + // Substitute: + // + // x = x' - a + // + // Plug into above equation: + // + // vn = A * x + b + // = A * (x' - a) + b + // = A * x' + b - A * a + // = A * x' + b' + // b' = b - A * a; + + b2ContactConstraintPoint* cp1 = c->points + 0; + b2ContactConstraintPoint* cp2 = c->points + 1; + + b2Vec2 a(cp1->normalImpulse, cp2->normalImpulse); + b2Assert(a.x >= 0.0f && a.y >= 0.0f); + + // Relative velocity at contact + b2Vec2 dv1 = vB + b2Cross(wB, cp1->rB) - vA - b2Cross(wA, cp1->rA); + b2Vec2 dv2 = vB + b2Cross(wB, cp2->rB) - vA - b2Cross(wA, cp2->rA); + + // Compute normal velocity + float32 vn1 = b2Dot(dv1, normal); + float32 vn2 = b2Dot(dv2, normal); + + b2Vec2 b; + b.x = vn1 - cp1->velocityBias; + b.y = vn2 - cp2->velocityBias; + b -= b2Mul(c->K, a); + + const float32 k_errorTol = 1e-3f; + B2_NOT_USED(k_errorTol); + + for (;;) + { + // + // Case 1: vn = 0 + // + // 0 = A * x' + b' + // + // Solve for x': + // + // x' = - inv(A) * b' + // + b2Vec2 x = - b2Mul(c->normalMass, b); + + if (x.x >= 0.0f && x.y >= 0.0f) + { + // Resubstitute for the incremental impulse + b2Vec2 d = x - a; + + // Apply incremental impulse + b2Vec2 P1 = d.x * normal; + b2Vec2 P2 = d.y * normal; + vA -= invMassA * (P1 + P2); + wA -= invIA * (b2Cross(cp1->rA, P1) + b2Cross(cp2->rA, P2)); + + vB += invMassB * (P1 + P2); + wB += invIB * (b2Cross(cp1->rB, P1) + b2Cross(cp2->rB, P2)); + + // Accumulate + cp1->normalImpulse = x.x; + cp2->normalImpulse = x.y; + +#if B2_DEBUG_SOLVER == 1 + // Postconditions + dv1 = vB + b2Cross(wB, cp1->rB) - vA - b2Cross(wA, cp1->rA); + dv2 = vB + b2Cross(wB, cp2->rB) - vA - b2Cross(wA, cp2->rA); + + // Compute normal velocity + vn1 = b2Dot(dv1, normal); + vn2 = b2Dot(dv2, normal); + + b2Assert(b2Abs(vn1 - cp1->velocityBias) < k_errorTol); + b2Assert(b2Abs(vn2 - cp2->velocityBias) < k_errorTol); +#endif + break; + } + + // + // Case 2: vn1 = 0 and x2 = 0 + // + // 0 = a11 * x1' + a12 * 0 + b1' + // vn2 = a21 * x1' + a22 * 0 + b2' + // + x.x = - cp1->normalMass * b.x; + x.y = 0.0f; + vn1 = 0.0f; + vn2 = c->K.col1.y * x.x + b.y; + + if (x.x >= 0.0f && vn2 >= 0.0f) + { + // Resubstitute for the incremental impulse + b2Vec2 d = x - a; + + // Apply incremental impulse + b2Vec2 P1 = d.x * normal; + b2Vec2 P2 = d.y * normal; + vA -= invMassA * (P1 + P2); + wA -= invIA * (b2Cross(cp1->rA, P1) + b2Cross(cp2->rA, P2)); + + vB += invMassB * (P1 + P2); + wB += invIB * (b2Cross(cp1->rB, P1) + b2Cross(cp2->rB, P2)); + + // Accumulate + cp1->normalImpulse = x.x; + cp2->normalImpulse = x.y; + +#if B2_DEBUG_SOLVER == 1 + // Postconditions + dv1 = vB + b2Cross(wB, cp1->rB) - vA - b2Cross(wA, cp1->rA); + + // Compute normal velocity + vn1 = b2Dot(dv1, normal); + + b2Assert(b2Abs(vn1 - cp1->velocityBias) < k_errorTol); +#endif + break; + } + + + // + // Case 3: vn2 = 0 and x1 = 0 + // + // vn1 = a11 * 0 + a12 * x2' + b1' + // 0 = a21 * 0 + a22 * x2' + b2' + // + x.x = 0.0f; + x.y = - cp2->normalMass * b.y; + vn1 = c->K.col2.x * x.y + b.x; + vn2 = 0.0f; + + if (x.y >= 0.0f && vn1 >= 0.0f) + { + // Resubstitute for the incremental impulse + b2Vec2 d = x - a; + + // Apply incremental impulse + b2Vec2 P1 = d.x * normal; + b2Vec2 P2 = d.y * normal; + vA -= invMassA * (P1 + P2); + wA -= invIA * (b2Cross(cp1->rA, P1) + b2Cross(cp2->rA, P2)); + + vB += invMassB * (P1 + P2); + wB += invIB * (b2Cross(cp1->rB, P1) + b2Cross(cp2->rB, P2)); + + // Accumulate + cp1->normalImpulse = x.x; + cp2->normalImpulse = x.y; + +#if B2_DEBUG_SOLVER == 1 + // Postconditions + dv2 = vB + b2Cross(wB, cp2->rB) - vA - b2Cross(wA, cp2->rA); + + // Compute normal velocity + vn2 = b2Dot(dv2, normal); + + b2Assert(b2Abs(vn2 - cp2->velocityBias) < k_errorTol); +#endif + break; + } + + // + // Case 4: x1 = 0 and x2 = 0 + // + // vn1 = b1 + // vn2 = b2; + x.x = 0.0f; + x.y = 0.0f; + vn1 = b.x; + vn2 = b.y; + + if (vn1 >= 0.0f && vn2 >= 0.0f ) + { + // Resubstitute for the incremental impulse + b2Vec2 d = x - a; + + // Apply incremental impulse + b2Vec2 P1 = d.x * normal; + b2Vec2 P2 = d.y * normal; + vA -= invMassA * (P1 + P2); + wA -= invIA * (b2Cross(cp1->rA, P1) + b2Cross(cp2->rA, P2)); + + vB += invMassB * (P1 + P2); + wB += invIB * (b2Cross(cp1->rB, P1) + b2Cross(cp2->rB, P2)); + + // Accumulate + cp1->normalImpulse = x.x; + cp2->normalImpulse = x.y; + + break; + } + + // No solution, give up. This is hit sometimes, but it doesn't seem to matter. + break; + } + } + + bodyA->m_linearVelocity = vA; + bodyA->m_angularVelocity = wA; + bodyB->m_linearVelocity = vB; + bodyB->m_angularVelocity = wB; + } +} + +void b2ContactSolver::StoreImpulses() +{ + for (int32 i = 0; i < m_constraintCount; ++i) + { + b2ContactConstraint* c = m_constraints + i; + b2Manifold* m = c->manifold; + + for (int32 j = 0; j < c->pointCount; ++j) + { + m->points[j].normalImpulse = c->points[j].normalImpulse; + m->points[j].tangentImpulse = c->points[j].tangentImpulse; + } + } +} + +struct b2PositionSolverManifold +{ + void Initialize(b2ContactConstraint* cc, int32 index) + { + b2Assert(cc->pointCount > 0); + + switch (cc->type) + { + case b2Manifold::e_circles: + { + b2Vec2 pointA = cc->bodyA->GetWorldPoint(cc->localPoint); + b2Vec2 pointB = cc->bodyB->GetWorldPoint(cc->points[0].localPoint); + if (b2DistanceSquared(pointA, pointB) > b2_epsilon * b2_epsilon) + { + normal = pointB - pointA; + normal.Normalize(); + } + else + { + normal.Set(1.0f, 0.0f); + } + + point = 0.5f * (pointA + pointB); + separation = b2Dot(pointB - pointA, normal) - cc->radius; + } + break; + + case b2Manifold::e_faceA: + { + normal = cc->bodyA->GetWorldVector(cc->localNormal); + b2Vec2 planePoint = cc->bodyA->GetWorldPoint(cc->localPoint); + + b2Vec2 clipPoint = cc->bodyB->GetWorldPoint(cc->points[index].localPoint); + separation = b2Dot(clipPoint - planePoint, normal) - cc->radius; + point = clipPoint; + } + break; + + case b2Manifold::e_faceB: + { + normal = cc->bodyB->GetWorldVector(cc->localNormal); + b2Vec2 planePoint = cc->bodyB->GetWorldPoint(cc->localPoint); + + b2Vec2 clipPoint = cc->bodyA->GetWorldPoint(cc->points[index].localPoint); + separation = b2Dot(clipPoint - planePoint, normal) - cc->radius; + point = clipPoint; + + // Ensure normal points from A to B + normal = -normal; + } + break; + } + } + + b2Vec2 normal; + b2Vec2 point; + float32 separation; +}; + +// Sequential solver. +bool b2ContactSolver::SolvePositionConstraints(float32 baumgarte) +{ + float32 minSeparation = 0.0f; + + for (int32 i = 0; i < m_constraintCount; ++i) + { + b2ContactConstraint* c = m_constraints + i; + b2Body* bodyA = c->bodyA; + b2Body* bodyB = c->bodyB; + + float32 invMassA = bodyA->m_mass * bodyA->m_invMass; + float32 invIA = bodyA->m_mass * bodyA->m_invI; + float32 invMassB = bodyB->m_mass * bodyB->m_invMass; + float32 invIB = bodyB->m_mass * bodyB->m_invI; + + // Solve normal constraints + for (int32 j = 0; j < c->pointCount; ++j) + { + b2PositionSolverManifold psm; + psm.Initialize(c, j); + b2Vec2 normal = psm.normal; + + b2Vec2 point = psm.point; + float32 separation = psm.separation; + + b2Vec2 rA = point - bodyA->m_sweep.c; + b2Vec2 rB = point - bodyB->m_sweep.c; + + // Track max constraint error. + minSeparation = b2Min(minSeparation, separation); + + // Prevent large corrections and allow slop. + float32 C = b2Clamp(baumgarte * (separation + b2_linearSlop), -b2_maxLinearCorrection, 0.0f); + + // Compute the effective mass. + float32 rnA = b2Cross(rA, normal); + float32 rnB = b2Cross(rB, normal); + float32 K = invMassA + invMassB + invIA * rnA * rnA + invIB * rnB * rnB; + + // Compute normal impulse + float32 impulse = K > 0.0f ? - C / K : 0.0f; + + b2Vec2 P = impulse * normal; + + bodyA->m_sweep.c -= invMassA * P; + bodyA->m_sweep.a -= invIA * b2Cross(rA, P); + bodyA->SynchronizeTransform(); + + bodyB->m_sweep.c += invMassB * P; + bodyB->m_sweep.a += invIB * b2Cross(rB, P); + bodyB->SynchronizeTransform(); + } + } + + // We can't expect minSpeparation >= -b2_linearSlop because we don't + // push the separation above -b2_linearSlop. + return minSeparation >= -1.5f * b2_linearSlop; +} diff --git a/uppsrc/plugin/box2d/b2ContactSolver.h b/uppsrc/plugin/box2d/b2ContactSolver.h new file mode 100644 index 000000000..df6c99d02 --- /dev/null +++ b/uppsrc/plugin/box2d/b2ContactSolver.h @@ -0,0 +1,78 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_CONTACT_SOLVER_H +#define B2_CONTACT_SOLVER_H + +#include "b2Math.h" +#include "b2Collision.h" +#include "b2Island.h" + +class b2Contact; +class b2Body; +class b2StackAllocator; + +struct b2ContactConstraintPoint +{ + b2Vec2 localPoint; + b2Vec2 rA; + b2Vec2 rB; + float32 normalImpulse; + float32 tangentImpulse; + float32 normalMass; + float32 tangentMass; + float32 velocityBias; +}; + +struct b2ContactConstraint +{ + b2ContactConstraintPoint points[b2_maxManifoldPoints]; + b2Vec2 localNormal; + b2Vec2 localPoint; + b2Vec2 normal; + b2Mat22 normalMass; + b2Mat22 K; + b2Body* bodyA; + b2Body* bodyB; + b2Manifold::Type type; + float32 radius; + float32 friction; + int32 pointCount; + b2Manifold* manifold; +}; + +class b2ContactSolver +{ +public: + b2ContactSolver(b2Contact** contacts, int32 contactCount, + b2StackAllocator* allocator, float32 impulseRatio); + + ~b2ContactSolver(); + + void WarmStart(); + void SolveVelocityConstraints(); + void StoreImpulses(); + + bool SolvePositionConstraints(float32 baumgarte); + + b2StackAllocator* m_allocator; + b2ContactConstraint* m_constraints; + int m_constraintCount; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2Distance.cpp b/uppsrc/plugin/box2d/b2Distance.cpp new file mode 100644 index 000000000..74c58aa12 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Distance.cpp @@ -0,0 +1,571 @@ +/* +* Copyright (c) 2007-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Distance.h" +#include "b2CircleShape.h" +#include "b2PolygonShape.h" + +// GJK using Voronoi regions (Christer Ericson) and Barycentric coordinates. +int32 b2_gjkCalls, b2_gjkIters, b2_gjkMaxIters; + +void b2DistanceProxy::Set(const b2Shape* shape) +{ + switch (shape->GetType()) + { + case b2Shape::e_circle: + { + const b2CircleShape* circle = (b2CircleShape*)shape; + m_vertices = &circle->m_p; + m_count = 1; + m_radius = circle->m_radius; + } + break; + + case b2Shape::e_polygon: + { + const b2PolygonShape* polygon = (b2PolygonShape*)shape; + m_vertices = polygon->m_vertices; + m_count = polygon->m_vertexCount; + m_radius = polygon->m_radius; + } + break; + + default: + b2Assert(false); + } +} + + +struct b2SimplexVertex +{ + b2Vec2 wA; // support point in proxyA + b2Vec2 wB; // support point in proxyB + b2Vec2 w; // wB - wA + float32 a; // barycentric coordinate for closest point + int32 indexA; // wA index + int32 indexB; // wB index +}; + +struct b2Simplex +{ + void ReadCache( const b2SimplexCache* cache, + const b2DistanceProxy* proxyA, const b2Transform& transformA, + const b2DistanceProxy* proxyB, const b2Transform& transformB) + { + b2Assert(cache->count <= 3); + + // Copy data from cache. + m_count = cache->count; + b2SimplexVertex* vertices = &m_v1; + for (int32 i = 0; i < m_count; ++i) + { + b2SimplexVertex* v = vertices + i; + v->indexA = cache->indexA[i]; + v->indexB = cache->indexB[i]; + b2Vec2 wALocal = proxyA->GetVertex(v->indexA); + b2Vec2 wBLocal = proxyB->GetVertex(v->indexB); + v->wA = b2Mul(transformA, wALocal); + v->wB = b2Mul(transformB, wBLocal); + v->w = v->wB - v->wA; + v->a = 0.0f; + } + + // Compute the new simplex metric, if it is substantially different than + // old metric then flush the simplex. + if (m_count > 1) + { + float32 metric1 = cache->metric; + float32 metric2 = GetMetric(); + if (metric2 < 0.5f * metric1 || 2.0f * metric1 < metric2 || metric2 < b2_epsilon) + { + // Reset the simplex. + m_count = 0; + } + } + + // If the cache is empty or invalid ... + if (m_count == 0) + { + b2SimplexVertex* v = vertices + 0; + v->indexA = 0; + v->indexB = 0; + b2Vec2 wALocal = proxyA->GetVertex(0); + b2Vec2 wBLocal = proxyB->GetVertex(0); + v->wA = b2Mul(transformA, wALocal); + v->wB = b2Mul(transformB, wBLocal); + v->w = v->wB - v->wA; + m_count = 1; + } + } + + void WriteCache(b2SimplexCache* cache) const + { + cache->metric = GetMetric(); + cache->count = uint16(m_count); + const b2SimplexVertex* vertices = &m_v1; + for (int32 i = 0; i < m_count; ++i) + { + cache->indexA[i] = uint8(vertices[i].indexA); + cache->indexB[i] = uint8(vertices[i].indexB); + } + } + + b2Vec2 GetSearchDirection() const + { + switch (m_count) + { + case 1: + return -m_v1.w; + + case 2: + { + b2Vec2 e12 = m_v2.w - m_v1.w; + float32 sgn = b2Cross(e12, -m_v1.w); + if (sgn > 0.0f) + { + // Origin is left of e12. + return b2Cross(1.0f, e12); + } + else + { + // Origin is right of e12. + return b2Cross(e12, 1.0f); + } + } + + default: + b2Assert(false); + return b2Vec2_zero; + } + } + + b2Vec2 GetClosestPoint() const + { + switch (m_count) + { + case 0: + b2Assert(false); + return b2Vec2_zero; + + case 1: + return m_v1.w; + + case 2: + return m_v1.a * m_v1.w + m_v2.a * m_v2.w; + + case 3: + return b2Vec2_zero; + + default: + b2Assert(false); + return b2Vec2_zero; + } + } + + void GetWitnessPoints(b2Vec2* pA, b2Vec2* pB) const + { + switch (m_count) + { + case 0: + b2Assert(false); + break; + + case 1: + *pA = m_v1.wA; + *pB = m_v1.wB; + break; + + case 2: + *pA = m_v1.a * m_v1.wA + m_v2.a * m_v2.wA; + *pB = m_v1.a * m_v1.wB + m_v2.a * m_v2.wB; + break; + + case 3: + *pA = m_v1.a * m_v1.wA + m_v2.a * m_v2.wA + m_v3.a * m_v3.wA; + *pB = *pA; + break; + + default: + b2Assert(false); + break; + } + } + + float32 GetMetric() const + { + switch (m_count) + { + case 0: + b2Assert(false); + return 0.0; + + case 1: + return 0.0f; + + case 2: + return b2Distance(m_v1.w, m_v2.w); + + case 3: + return b2Cross(m_v2.w - m_v1.w, m_v3.w - m_v1.w); + + default: + b2Assert(false); + return 0.0f; + } + } + + void Solve2(); + void Solve3(); + + b2SimplexVertex m_v1, m_v2, m_v3; + int32 m_count; +}; + + +// Solve a line segment using barycentric coordinates. +// +// p = a1 * w1 + a2 * w2 +// a1 + a2 = 1 +// +// The vector from the origin to the closest point on the line is +// perpendicular to the line. +// e12 = w2 - w1 +// dot(p, e) = 0 +// a1 * dot(w1, e) + a2 * dot(w2, e) = 0 +// +// 2-by-2 linear system +// [1 1 ][a1] = [1] +// [w1.e12 w2.e12][a2] = [0] +// +// Define +// d12_1 = dot(w2, e12) +// d12_2 = -dot(w1, e12) +// d12 = d12_1 + d12_2 +// +// Solution +// a1 = d12_1 / d12 +// a2 = d12_2 / d12 +void b2Simplex::Solve2() +{ + b2Vec2 w1 = m_v1.w; + b2Vec2 w2 = m_v2.w; + b2Vec2 e12 = w2 - w1; + + // w1 region + float32 d12_2 = -b2Dot(w1, e12); + if (d12_2 <= 0.0f) + { + // a2 <= 0, so we clamp it to 0 + m_v1.a = 1.0f; + m_count = 1; + return; + } + + // w2 region + float32 d12_1 = b2Dot(w2, e12); + if (d12_1 <= 0.0f) + { + // a1 <= 0, so we clamp it to 0 + m_v2.a = 1.0f; + m_count = 1; + m_v1 = m_v2; + return; + } + + // Must be in e12 region. + float32 inv_d12 = 1.0f / (d12_1 + d12_2); + m_v1.a = d12_1 * inv_d12; + m_v2.a = d12_2 * inv_d12; + m_count = 2; +} + +// Possible regions: +// - points[2] +// - edge points[0]-points[2] +// - edge points[1]-points[2] +// - inside the triangle +void b2Simplex::Solve3() +{ + b2Vec2 w1 = m_v1.w; + b2Vec2 w2 = m_v2.w; + b2Vec2 w3 = m_v3.w; + + // Edge12 + // [1 1 ][a1] = [1] + // [w1.e12 w2.e12][a2] = [0] + // a3 = 0 + b2Vec2 e12 = w2 - w1; + float32 w1e12 = b2Dot(w1, e12); + float32 w2e12 = b2Dot(w2, e12); + float32 d12_1 = w2e12; + float32 d12_2 = -w1e12; + + // Edge13 + // [1 1 ][a1] = [1] + // [w1.e13 w3.e13][a3] = [0] + // a2 = 0 + b2Vec2 e13 = w3 - w1; + float32 w1e13 = b2Dot(w1, e13); + float32 w3e13 = b2Dot(w3, e13); + float32 d13_1 = w3e13; + float32 d13_2 = -w1e13; + + // Edge23 + // [1 1 ][a2] = [1] + // [w2.e23 w3.e23][a3] = [0] + // a1 = 0 + b2Vec2 e23 = w3 - w2; + float32 w2e23 = b2Dot(w2, e23); + float32 w3e23 = b2Dot(w3, e23); + float32 d23_1 = w3e23; + float32 d23_2 = -w2e23; + + // Triangle123 + float32 n123 = b2Cross(e12, e13); + + float32 d123_1 = n123 * b2Cross(w2, w3); + float32 d123_2 = n123 * b2Cross(w3, w1); + float32 d123_3 = n123 * b2Cross(w1, w2); + + // w1 region + if (d12_2 <= 0.0f && d13_2 <= 0.0f) + { + m_v1.a = 1.0f; + m_count = 1; + return; + } + + // e12 + if (d12_1 > 0.0f && d12_2 > 0.0f && d123_3 <= 0.0f) + { + float32 inv_d12 = 1.0f / (d12_1 + d12_2); + m_v1.a = d12_1 * inv_d12; + m_v2.a = d12_2 * inv_d12; + m_count = 2; + return; + } + + // e13 + if (d13_1 > 0.0f && d13_2 > 0.0f && d123_2 <= 0.0f) + { + float32 inv_d13 = 1.0f / (d13_1 + d13_2); + m_v1.a = d13_1 * inv_d13; + m_v3.a = d13_2 * inv_d13; + m_count = 2; + m_v2 = m_v3; + return; + } + + // w2 region + if (d12_1 <= 0.0f && d23_2 <= 0.0f) + { + m_v2.a = 1.0f; + m_count = 1; + m_v1 = m_v2; + return; + } + + // w3 region + if (d13_1 <= 0.0f && d23_1 <= 0.0f) + { + m_v3.a = 1.0f; + m_count = 1; + m_v1 = m_v3; + return; + } + + // e23 + if (d23_1 > 0.0f && d23_2 > 0.0f && d123_1 <= 0.0f) + { + float32 inv_d23 = 1.0f / (d23_1 + d23_2); + m_v2.a = d23_1 * inv_d23; + m_v3.a = d23_2 * inv_d23; + m_count = 2; + m_v1 = m_v3; + return; + } + + // Must be in triangle123 + float32 inv_d123 = 1.0f / (d123_1 + d123_2 + d123_3); + m_v1.a = d123_1 * inv_d123; + m_v2.a = d123_2 * inv_d123; + m_v3.a = d123_3 * inv_d123; + m_count = 3; +} + +void b2Distance(b2DistanceOutput* output, + b2SimplexCache* cache, + const b2DistanceInput* input) +{ + ++b2_gjkCalls; + + const b2DistanceProxy* proxyA = &input->proxyA; + const b2DistanceProxy* proxyB = &input->proxyB; + + b2Transform transformA = input->transformA; + b2Transform transformB = input->transformB; + + // Initialize the simplex. + b2Simplex simplex; + simplex.ReadCache(cache, proxyA, transformA, proxyB, transformB); + + // Get simplex vertices as an array. + b2SimplexVertex* vertices = &simplex.m_v1; + const int32 k_maxIters = 20; + + // These store the vertices of the last simplex so that we + // can check for duplicates and prevent cycling. + int32 saveA[3], saveB[3]; + int32 saveCount = 0; + + b2Vec2 closestPoint = simplex.GetClosestPoint(); + float32 distanceSqr1 = closestPoint.LengthSquared(); + float32 distanceSqr2 = distanceSqr1; + + // Main iteration loop. + int32 iter = 0; + while (iter < k_maxIters) + { + // Copy simplex so we can identify duplicates. + saveCount = simplex.m_count; + for (int32 i = 0; i < saveCount; ++i) + { + saveA[i] = vertices[i].indexA; + saveB[i] = vertices[i].indexB; + } + + switch (simplex.m_count) + { + case 1: + break; + + case 2: + simplex.Solve2(); + break; + + case 3: + simplex.Solve3(); + break; + + default: + b2Assert(false); + } + + // If we have 3 points, then the origin is in the corresponding triangle. + if (simplex.m_count == 3) + { + break; + } + + // Compute closest point. + b2Vec2 p = simplex.GetClosestPoint(); + distanceSqr2 = p.LengthSquared(); + + // Ensure progress + if (distanceSqr2 >= distanceSqr1) + { + //break; + } + distanceSqr1 = distanceSqr2; + + // Get search direction. + b2Vec2 d = simplex.GetSearchDirection(); + + // Ensure the search direction is numerically fit. + if (d.LengthSquared() < b2_epsilon * b2_epsilon) + { + // The origin is probably contained by a line segment + // or triangle. Thus the shapes are overlapped. + + // We can't return zero here even though there may be overlap. + // In case the simplex is a point, segment, or triangle it is difficult + // to determine if the origin is contained in the CSO or very close to it. + break; + } + + // Compute a tentative new simplex vertex using support points. + b2SimplexVertex* vertex = vertices + simplex.m_count; + vertex->indexA = proxyA->GetSupport(b2MulT(transformA.R, -d)); + vertex->wA = b2Mul(transformA, proxyA->GetVertex(vertex->indexA)); + b2Vec2 wBLocal; + vertex->indexB = proxyB->GetSupport(b2MulT(transformB.R, d)); + vertex->wB = b2Mul(transformB, proxyB->GetVertex(vertex->indexB)); + vertex->w = vertex->wB - vertex->wA; + + // Iteration count is equated to the number of support point calls. + ++iter; + ++b2_gjkIters; + + // Check for duplicate support points. This is the main termination criteria. + bool duplicate = false; + for (int32 i = 0; i < saveCount; ++i) + { + if (vertex->indexA == saveA[i] && vertex->indexB == saveB[i]) + { + duplicate = true; + break; + } + } + + // If we found a duplicate support point we must exit to avoid cycling. + if (duplicate) + { + break; + } + + // New vertex is ok and needed. + ++simplex.m_count; + } + + b2_gjkMaxIters = b2Max(b2_gjkMaxIters, iter); + + // Prepare output. + simplex.GetWitnessPoints(&output->pointA, &output->pointB); + output->distance = b2Distance(output->pointA, output->pointB); + output->iterations = iter; + + // Cache the simplex. + simplex.WriteCache(cache); + + // Apply radii if requested. + if (input->useRadii) + { + float32 rA = proxyA->m_radius; + float32 rB = proxyB->m_radius; + + if (output->distance > rA + rB && output->distance > b2_epsilon) + { + // Shapes are still no overlapped. + // Move the witness points to the outer surface. + output->distance -= rA + rB; + b2Vec2 normal = output->pointB - output->pointA; + normal.Normalize(); + output->pointA += rA * normal; + output->pointB -= rB * normal; + } + else + { + // Shapes are overlapped when radii are considered. + // Move the witness points to the middle. + b2Vec2 p = 0.5f * (output->pointA + output->pointB); + output->pointA = p; + output->pointB = p; + output->distance = 0.0f; + } + } +} diff --git a/uppsrc/plugin/box2d/b2Distance.h b/uppsrc/plugin/box2d/b2Distance.h new file mode 100644 index 000000000..929ce215a --- /dev/null +++ b/uppsrc/plugin/box2d/b2Distance.h @@ -0,0 +1,141 @@ + +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_DISTANCE_H +#define B2_DISTANCE_H + +#include "b2Math.h" +#include + +class b2Shape; + +/// A distance proxy is used by the GJK algorithm. +/// It encapsulates any shape. +struct b2DistanceProxy +{ + b2DistanceProxy() : m_vertices(NULL), m_count(0), m_radius(0.0f) {} + + /// Initialize the proxy using the given shape. The shape + /// must remain in scope while the proxy is in use. + void Set(const b2Shape* shape); + + /// Get the supporting vertex index in the given direction. + int32 GetSupport(const b2Vec2& d) const; + + /// Get the supporting vertex in the given direction. + const b2Vec2& GetSupportVertex(const b2Vec2& d) const; + + /// Get the vertex count. + int32 GetVertexCount() const; + + /// Get a vertex by index. Used by b2Distance. + const b2Vec2& GetVertex(int32 index) const; + + const b2Vec2* m_vertices; + int32 m_count; + float32 m_radius; +}; + +/// Used to warm start b2Distance. +/// Set count to zero on first call. +struct b2SimplexCache +{ + float32 metric; ///< length or area + uint16 count; + uint8 indexA[3]; ///< vertices on shape A + uint8 indexB[3]; ///< vertices on shape B +}; + +/// Input for b2Distance. +/// You have to option to use the shape radii +/// in the computation. Even +struct b2DistanceInput +{ + b2DistanceProxy proxyA; + b2DistanceProxy proxyB; + b2Transform transformA; + b2Transform transformB; + bool useRadii; +}; + +/// Output for b2Distance. +struct b2DistanceOutput +{ + b2Vec2 pointA; ///< closest point on shapeA + b2Vec2 pointB; ///< closest point on shapeB + float32 distance; + int32 iterations; ///< number of GJK iterations used +}; + +/// Compute the closest points between two shapes. Supports any combination of: +/// b2CircleShape, b2PolygonShape, b2EdgeShape. The simplex cache is input/output. +/// On the first call set b2SimplexCache.count to zero. +void b2Distance(b2DistanceOutput* output, + b2SimplexCache* cache, + const b2DistanceInput* input); + + +////////////////////////////////////////////////////////////////////////// + +inline int32 b2DistanceProxy::GetVertexCount() const +{ + return m_count; +} + +inline const b2Vec2& b2DistanceProxy::GetVertex(int32 index) const +{ + b2Assert(0 <= index && index < m_count); + return m_vertices[index]; +} + +inline int32 b2DistanceProxy::GetSupport(const b2Vec2& d) const +{ + int32 bestIndex = 0; + float32 bestValue = b2Dot(m_vertices[0], d); + for (int32 i = 1; i < m_count; ++i) + { + float32 value = b2Dot(m_vertices[i], d); + if (value > bestValue) + { + bestIndex = i; + bestValue = value; + } + } + + return bestIndex; +} + +inline const b2Vec2& b2DistanceProxy::GetSupportVertex(const b2Vec2& d) const +{ + int32 bestIndex = 0; + float32 bestValue = b2Dot(m_vertices[0], d); + for (int32 i = 1; i < m_count; ++i) + { + float32 value = b2Dot(m_vertices[i], d); + if (value > bestValue) + { + bestIndex = i; + bestValue = value; + } + } + + return m_vertices[bestIndex]; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2DistanceJoint.cpp b/uppsrc/plugin/box2d/b2DistanceJoint.cpp new file mode 100644 index 000000000..ab1549604 --- /dev/null +++ b/uppsrc/plugin/box2d/b2DistanceJoint.cpp @@ -0,0 +1,211 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2DistanceJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// 1-D constrained system +// m (v2 - v1) = lambda +// v2 + (beta/h) * x1 + gamma * lambda = 0, gamma has units of inverse mass. +// x2 = x1 + h * v2 + +// 1-D mass-damper-spring system +// m (v2 - v1) + h * d * v2 + h * k * + +// C = norm(p2 - p1) - L +// u = (p2 - p1) / norm(p2 - p1) +// Cdot = dot(u, v2 + cross(w2, r2) - v1 - cross(w1, r1)) +// J = [-u -cross(r1, u) u cross(r2, u)] +// K = J * invM * JT +// = invMass1 + invI1 * cross(r1, u)^2 + invMass2 + invI2 * cross(r2, u)^2 + +void b2DistanceJointDef::Initialize(b2Body* b1, b2Body* b2, + const b2Vec2& anchor1, const b2Vec2& anchor2) +{ + bodyA = b1; + bodyB = b2; + localAnchorA = bodyA->GetLocalPoint(anchor1); + localAnchorB = bodyB->GetLocalPoint(anchor2); + b2Vec2 d = anchor2 - anchor1; + length = d.Length(); +} + + +b2DistanceJoint::b2DistanceJoint(const b2DistanceJointDef* def) +: b2Joint(def) +{ + m_localAnchor1 = def->localAnchorA; + m_localAnchor2 = def->localAnchorB; + m_length = def->length; + m_frequencyHz = def->frequencyHz; + m_dampingRatio = def->dampingRatio; + m_impulse = 0.0f; + m_gamma = 0.0f; + m_bias = 0.0f; +} + +void b2DistanceJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + // Compute the effective mass matrix. + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + m_u = b2->m_sweep.c + r2 - b1->m_sweep.c - r1; + + // Handle singularity. + float32 length = m_u.Length(); + if (length > b2_linearSlop) + { + m_u *= 1.0f / length; + } + else + { + m_u.Set(0.0f, 0.0f); + } + + float32 cr1u = b2Cross(r1, m_u); + float32 cr2u = b2Cross(r2, m_u); + float32 invMass = b1->m_invMass + b1->m_invI * cr1u * cr1u + b2->m_invMass + b2->m_invI * cr2u * cr2u; + + m_mass = invMass != 0.0f ? 1.0f / invMass : 0.0f; + + if (m_frequencyHz > 0.0f) + { + float32 C = length - m_length; + + // Frequency + float32 omega = 2.0f * b2_pi * m_frequencyHz; + + // Damping coefficient + float32 d = 2.0f * m_mass * m_dampingRatio * omega; + + // Spring stiffness + float32 k = m_mass * omega * omega; + + // magic formulas + m_gamma = step.dt * (d + step.dt * k); + m_gamma = m_gamma != 0.0f ? 1.0f / m_gamma : 0.0f; + m_bias = C * step.dt * k * m_gamma; + + m_mass = invMass + m_gamma; + m_mass = m_mass != 0.0f ? 1.0f / m_mass : 0.0f; + } + + if (step.warmStarting) + { + // Scale the impulse to support a variable time step. + m_impulse *= step.dtRatio; + + b2Vec2 P = m_impulse * m_u; + b1->m_linearVelocity -= b1->m_invMass * P; + b1->m_angularVelocity -= b1->m_invI * b2Cross(r1, P); + b2->m_linearVelocity += b2->m_invMass * P; + b2->m_angularVelocity += b2->m_invI * b2Cross(r2, P); + } + else + { + m_impulse = 0.0f; + } +} + +void b2DistanceJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + B2_NOT_USED(step); + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + // Cdot = dot(u, v + cross(w, r)) + b2Vec2 v1 = b1->m_linearVelocity + b2Cross(b1->m_angularVelocity, r1); + b2Vec2 v2 = b2->m_linearVelocity + b2Cross(b2->m_angularVelocity, r2); + float32 Cdot = b2Dot(m_u, v2 - v1); + + float32 impulse = -m_mass * (Cdot + m_bias + m_gamma * m_impulse); + m_impulse += impulse; + + b2Vec2 P = impulse * m_u; + b1->m_linearVelocity -= b1->m_invMass * P; + b1->m_angularVelocity -= b1->m_invI * b2Cross(r1, P); + b2->m_linearVelocity += b2->m_invMass * P; + b2->m_angularVelocity += b2->m_invI * b2Cross(r2, P); +} + +bool b2DistanceJoint::SolvePositionConstraints(float32 baumgarte) +{ + B2_NOT_USED(baumgarte); + + if (m_frequencyHz > 0.0f) + { + // There is no position correction for soft distance constraints. + return true; + } + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + b2Vec2 d = b2->m_sweep.c + r2 - b1->m_sweep.c - r1; + + float32 length = d.Normalize(); + float32 C = length - m_length; + C = b2Clamp(C, -b2_maxLinearCorrection, b2_maxLinearCorrection); + + float32 impulse = -m_mass * C; + m_u = d; + b2Vec2 P = impulse * m_u; + + b1->m_sweep.c -= b1->m_invMass * P; + b1->m_sweep.a -= b1->m_invI * b2Cross(r1, P); + b2->m_sweep.c += b2->m_invMass * P; + b2->m_sweep.a += b2->m_invI * b2Cross(r2, P); + + b1->SynchronizeTransform(); + b2->SynchronizeTransform(); + + return b2Abs(C) < b2_linearSlop; +} + +b2Vec2 b2DistanceJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchor1); +} + +b2Vec2 b2DistanceJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchor2); +} + +b2Vec2 b2DistanceJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 F = (inv_dt * m_impulse) * m_u; + return F; +} + +float32 b2DistanceJoint::GetReactionTorque(float32 inv_dt) const +{ + B2_NOT_USED(inv_dt); + return 0.0f; +} diff --git a/uppsrc/plugin/box2d/b2DistanceJoint.h b/uppsrc/plugin/box2d/b2DistanceJoint.h new file mode 100644 index 000000000..f3b9fe021 --- /dev/null +++ b/uppsrc/plugin/box2d/b2DistanceJoint.h @@ -0,0 +1,140 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_DISTANCE_JOINT_H +#define B2_DISTANCE_JOINT_H + +#include "b2Joint.h" + +/// Distance joint definition. This requires defining an +/// anchor point on both bodies and the non-zero length of the +/// distance joint. The definition uses local anchor points +/// so that the initial configuration can violate the constraint +/// slightly. This helps when saving and loading a game. +/// @warning Do not use a zero or short length. +struct b2DistanceJointDef : public b2JointDef +{ + b2DistanceJointDef() + { + type = e_distanceJoint; + localAnchorA.Set(0.0f, 0.0f); + localAnchorB.Set(0.0f, 0.0f); + length = 1.0f; + frequencyHz = 0.0f; + dampingRatio = 0.0f; + } + + /// Initialize the bodies, anchors, and length using the world + /// anchors. + void Initialize(b2Body* bodyA, b2Body* bodyB, + const b2Vec2& anchorA, const b2Vec2& anchorB); + + /// The local anchor point relative to body1's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to body2's origin. + b2Vec2 localAnchorB; + + /// The natural length between the anchor points. + float32 length; + + /// The mass-spring-damper frequency in Hertz. + float32 frequencyHz; + + /// The damping ratio. 0 = no damping, 1 = critical damping. + float32 dampingRatio; +}; + +/// A distance joint constrains two points on two bodies +/// to remain at a fixed distance from each other. You can view +/// this as a massless, rigid rod. +class b2DistanceJoint : public b2Joint +{ +public: + + b2Vec2 GetAnchorA() const; + b2Vec2 GetAnchorB() const; + + b2Vec2 GetReactionForce(float32 inv_dt) const; + float32 GetReactionTorque(float32 inv_dt) const; + + /// Set/get the natural length. + /// Manipulating the length can lead to non-physical behavior when the frequency is zero. + void SetLength(float32 length); + float32 GetLength() const; + + // Set/get frequency in Hz. + void SetFrequency(float32 hz); + float32 GetFrequency() const; + + // Set/get damping ratio. + void SetDampingRatio(float32 ratio); + float32 GetDampingRatio() const; + +protected: + + friend class b2Joint; + b2DistanceJoint(const b2DistanceJointDef* data); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + bool SolvePositionConstraints(float32 baumgarte); + + b2Vec2 m_localAnchor1; + b2Vec2 m_localAnchor2; + b2Vec2 m_u; + float32 m_frequencyHz; + float32 m_dampingRatio; + float32 m_gamma; + float32 m_bias; + float32 m_impulse; + float32 m_mass; + float32 m_length; +}; + +inline void b2DistanceJoint::SetLength(float32 length) +{ + m_length = length; +} + +inline float32 b2DistanceJoint::GetLength() const +{ + return m_length; +} + +inline void b2DistanceJoint::SetFrequency(float32 hz) +{ + m_frequencyHz = hz; +} + +inline float32 b2DistanceJoint::GetFrequency() const +{ + return m_frequencyHz; +} + +inline void b2DistanceJoint::SetDampingRatio(float32 ratio) +{ + m_dampingRatio = ratio; +} + +inline float32 b2DistanceJoint::GetDampingRatio() const +{ + return m_dampingRatio; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2DynamicTree.cpp b/uppsrc/plugin/box2d/b2DynamicTree.cpp new file mode 100644 index 000000000..d549f432b --- /dev/null +++ b/uppsrc/plugin/box2d/b2DynamicTree.cpp @@ -0,0 +1,365 @@ +/* +* Copyright (c) 2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2DynamicTree.h" +#include +#include + +b2DynamicTree::b2DynamicTree() +{ + m_root = b2_nullNode; + + m_nodeCapacity = 16; + m_nodeCount = 0; + m_nodes = (b2DynamicTreeNode*)b2Alloc(m_nodeCapacity * sizeof(b2DynamicTreeNode)); + memset(m_nodes, 0, m_nodeCapacity * sizeof(b2DynamicTreeNode)); + + // Build a linked list for the free list. + for (int32 i = 0; i < m_nodeCapacity - 1; ++i) + { + m_nodes[i].next = i + 1; + } + m_nodes[m_nodeCapacity-1].next = b2_nullNode; + m_freeList = 0; + + m_path = 0; + + m_insertionCount = 0; +} + +b2DynamicTree::~b2DynamicTree() +{ + // This frees the entire tree in one shot. + b2Free(m_nodes); +} + +// Allocate a node from the pool. Grow the pool if necessary. +int32 b2DynamicTree::AllocateNode() +{ + // Expand the node pool as needed. + if (m_freeList == b2_nullNode) + { + b2Assert(m_nodeCount == m_nodeCapacity); + + // The free list is empty. Rebuild a bigger pool. + b2DynamicTreeNode* oldNodes = m_nodes; + m_nodeCapacity *= 2; + m_nodes = (b2DynamicTreeNode*)b2Alloc(m_nodeCapacity * sizeof(b2DynamicTreeNode)); + memcpy(m_nodes, oldNodes, m_nodeCount * sizeof(b2DynamicTreeNode)); + b2Free(oldNodes); + + // Build a linked list for the free list. The parent + // pointer becomes the "next" pointer. + for (int32 i = m_nodeCount; i < m_nodeCapacity - 1; ++i) + { + m_nodes[i].next = i + 1; + } + m_nodes[m_nodeCapacity-1].next = b2_nullNode; + m_freeList = m_nodeCount; + } + + // Peel a node off the free list. + int32 nodeId = m_freeList; + m_freeList = m_nodes[nodeId].next; + m_nodes[nodeId].parent = b2_nullNode; + m_nodes[nodeId].child1 = b2_nullNode; + m_nodes[nodeId].child2 = b2_nullNode; + ++m_nodeCount; + return nodeId; +} + +// Return a node to the pool. +void b2DynamicTree::FreeNode(int32 nodeId) +{ + b2Assert(0 <= nodeId && nodeId < m_nodeCapacity); + b2Assert(0 < m_nodeCount); + m_nodes[nodeId].next = m_freeList; + m_freeList = nodeId; + --m_nodeCount; +} + +// Create a proxy in the tree as a leaf node. We return the index +// of the node instead of a pointer so that we can grow +// the node pool. +int32 b2DynamicTree::CreateProxy(const b2AABB& aabb, void* userData) +{ + int32 proxyId = AllocateNode(); + + // Fatten the aabb. + b2Vec2 r(b2_aabbExtension, b2_aabbExtension); + m_nodes[proxyId].aabb.lowerBound = aabb.lowerBound - r; + m_nodes[proxyId].aabb.upperBound = aabb.upperBound + r; + m_nodes[proxyId].userData = userData; + + InsertLeaf(proxyId); + + // Rebalance if necessary. + int32 iterationCount = m_nodeCount >> 4; + int32 tryCount = 0; + int32 height = ComputeHeight(); + while (height > 64 && tryCount < 10) + { + Rebalance(iterationCount); + height = ComputeHeight(); + ++tryCount; + } + + return proxyId; +} + +void b2DynamicTree::DestroyProxy(int32 proxyId) +{ + b2Assert(0 <= proxyId && proxyId < m_nodeCapacity); + b2Assert(m_nodes[proxyId].IsLeaf()); + + RemoveLeaf(proxyId); + FreeNode(proxyId); +} + +bool b2DynamicTree::MoveProxy(int32 proxyId, const b2AABB& aabb, const b2Vec2& displacement) +{ + b2Assert(0 <= proxyId && proxyId < m_nodeCapacity); + + b2Assert(m_nodes[proxyId].IsLeaf()); + + if (m_nodes[proxyId].aabb.Contains(aabb)) + { + return false; + } + + RemoveLeaf(proxyId); + + // Extend AABB. + b2AABB b = aabb; + b2Vec2 r(b2_aabbExtension, b2_aabbExtension); + b.lowerBound = b.lowerBound - r; + b.upperBound = b.upperBound + r; + + // Predict AABB displacement. + b2Vec2 d = b2_aabbMultiplier * displacement; + + if (d.x < 0.0f) + { + b.lowerBound.x += d.x; + } + else + { + b.upperBound.x += d.x; + } + + if (d.y < 0.0f) + { + b.lowerBound.y += d.y; + } + else + { + b.upperBound.y += d.y; + } + + m_nodes[proxyId].aabb = b; + + InsertLeaf(proxyId); + return true; +} + +void b2DynamicTree::InsertLeaf(int32 leaf) +{ + ++m_insertionCount; + + if (m_root == b2_nullNode) + { + m_root = leaf; + m_nodes[m_root].parent = b2_nullNode; + return; + } + + // Find the best sibling for this node. + b2Vec2 center = m_nodes[leaf].aabb.GetCenter(); + int32 sibling = m_root; + if (m_nodes[sibling].IsLeaf() == false) + { + do + { + int32 child1 = m_nodes[sibling].child1; + int32 child2 = m_nodes[sibling].child2; + + b2Vec2 delta1 = b2Abs(m_nodes[child1].aabb.GetCenter() - center); + b2Vec2 delta2 = b2Abs(m_nodes[child2].aabb.GetCenter() - center); + + float32 norm1 = delta1.x + delta1.y; + float32 norm2 = delta2.x + delta2.y; + + if (norm1 < norm2) + { + sibling = child1; + } + else + { + sibling = child2; + } + + } + while(m_nodes[sibling].IsLeaf() == false); + } + + // Create a parent for the siblings. + int32 node1 = m_nodes[sibling].parent; + int32 node2 = AllocateNode(); + m_nodes[node2].parent = node1; + m_nodes[node2].userData = NULL; + m_nodes[node2].aabb.Combine(m_nodes[leaf].aabb, m_nodes[sibling].aabb); + + if (node1 != b2_nullNode) + { + if (m_nodes[m_nodes[sibling].parent].child1 == sibling) + { + m_nodes[node1].child1 = node2; + } + else + { + m_nodes[node1].child2 = node2; + } + + m_nodes[node2].child1 = sibling; + m_nodes[node2].child2 = leaf; + m_nodes[sibling].parent = node2; + m_nodes[leaf].parent = node2; + + do + { + if (m_nodes[node1].aabb.Contains(m_nodes[node2].aabb)) + { + break; + } + + m_nodes[node1].aabb.Combine(m_nodes[m_nodes[node1].child1].aabb, m_nodes[m_nodes[node1].child2].aabb); + node2 = node1; + node1 = m_nodes[node1].parent; + } + while(node1 != b2_nullNode); + } + else + { + m_nodes[node2].child1 = sibling; + m_nodes[node2].child2 = leaf; + m_nodes[sibling].parent = node2; + m_nodes[leaf].parent = node2; + m_root = node2; + } +} + +void b2DynamicTree::RemoveLeaf(int32 leaf) +{ + if (leaf == m_root) + { + m_root = b2_nullNode; + return; + } + + int32 node2 = m_nodes[leaf].parent; + int32 node1 = m_nodes[node2].parent; + int32 sibling; + if (m_nodes[node2].child1 == leaf) + { + sibling = m_nodes[node2].child2; + } + else + { + sibling = m_nodes[node2].child1; + } + + if (node1 != b2_nullNode) + { + // Destroy node2 and connect node1 to sibling. + if (m_nodes[node1].child1 == node2) + { + m_nodes[node1].child1 = sibling; + } + else + { + m_nodes[node1].child2 = sibling; + } + m_nodes[sibling].parent = node1; + FreeNode(node2); + + // Adjust ancestor bounds. + while (node1 != b2_nullNode) + { + b2AABB oldAABB = m_nodes[node1].aabb; + m_nodes[node1].aabb.Combine(m_nodes[m_nodes[node1].child1].aabb, m_nodes[m_nodes[node1].child2].aabb); + + if (oldAABB.Contains(m_nodes[node1].aabb)) + { + break; + } + + node1 = m_nodes[node1].parent; + } + } + else + { + m_root = sibling; + m_nodes[sibling].parent = b2_nullNode; + FreeNode(node2); + } +} + +void b2DynamicTree::Rebalance(int32 iterations) +{ + if (m_root == b2_nullNode) + { + return; + } + + for (int32 i = 0; i < iterations; ++i) + { + int32 node = m_root; + + uint32 bit = 0; + while (m_nodes[node].IsLeaf() == false) + { + int32* children = &m_nodes[node].child1; + node = children[(m_path >> bit) & 1]; + bit = (bit + 1) & (8* sizeof(uint32) - 1); + } + ++m_path; + + RemoveLeaf(node); + InsertLeaf(node); + } +} + +// Compute the height of a sub-tree. +int32 b2DynamicTree::ComputeHeight(int32 nodeId) const +{ + if (nodeId == b2_nullNode) + { + return 0; + } + + b2Assert(0 <= nodeId && nodeId < m_nodeCapacity); + b2DynamicTreeNode* node = m_nodes + nodeId; + int32 height1 = ComputeHeight(node->child1); + int32 height2 = ComputeHeight(node->child2); + return 1 + b2Max(height1, height2); +} + +int32 b2DynamicTree::ComputeHeight() const +{ + return ComputeHeight(m_root); +} diff --git a/uppsrc/plugin/box2d/b2DynamicTree.h b/uppsrc/plugin/box2d/b2DynamicTree.h new file mode 100644 index 000000000..c8d9d8997 --- /dev/null +++ b/uppsrc/plugin/box2d/b2DynamicTree.h @@ -0,0 +1,286 @@ +/* +* Copyright (c) 2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_DYNAMIC_TREE_H +#define B2_DYNAMIC_TREE_H + +#include "b2Collision.h" + +/// A dynamic AABB tree broad-phase, inspired by Nathanael Presson's btDbvt. + +#define b2_nullNode (-1) + +/// A node in the dynamic tree. The client does not interact with this directly. +struct b2DynamicTreeNode +{ + bool IsLeaf() const + { + return child1 == b2_nullNode; + } + + /// This is the fattened AABB. + b2AABB aabb; + + //int32 userData; + void* userData; + + union + { + int32 parent; + int32 next; + }; + + int32 child1; + int32 child2; +}; + +/// A dynamic tree arranges data in a binary tree to accelerate +/// queries such as volume queries and ray casts. Leafs are proxies +/// with an AABB. In the tree we expand the proxy AABB by b2_fatAABBFactor +/// so that the proxy AABB is bigger than the client object. This allows the client +/// object to move by small amounts without triggering a tree update. +/// +/// Nodes are pooled and relocatable, so we use node indices rather than pointers. +class b2DynamicTree +{ +public: + + /// Constructing the tree initializes the node pool. + b2DynamicTree(); + + /// Destroy the tree, freeing the node pool. + ~b2DynamicTree(); + + /// Create a proxy. Provide a tight fitting AABB and a userData pointer. + int32 CreateProxy(const b2AABB& aabb, void* userData); + + /// Destroy a proxy. This asserts if the id is invalid. + void DestroyProxy(int32 proxyId); + + /// Move a proxy with a swepted AABB. If the proxy has moved outside of its fattened AABB, + /// then the proxy is removed from the tree and re-inserted. Otherwise + /// the function returns immediately. + /// @return true if the proxy was re-inserted. + bool MoveProxy(int32 proxyId, const b2AABB& aabb1, const b2Vec2& displacement); + + /// Perform some iterations to re-balance the tree. + void Rebalance(int32 iterations); + + /// Get proxy user data. + /// @return the proxy user data or 0 if the id is invalid. + void* GetUserData(int32 proxyId) const; + + /// Get the fat AABB for a proxy. + const b2AABB& GetFatAABB(int32 proxyId) const; + + /// Compute the height of the tree. + int32 ComputeHeight() const; + + /// Query an AABB for overlapping proxies. The callback class + /// is called for each proxy that overlaps the supplied AABB. + template + void Query(T* callback, const b2AABB& aabb) const; + + /// Ray-cast against the proxies in the tree. This relies on the callback + /// to perform a exact ray-cast in the case were the proxy contains a shape. + /// The callback also performs the any collision filtering. This has performance + /// roughly equal to k * log(n), where k is the number of collisions and n is the + /// number of proxies in the tree. + /// @param input the ray-cast input data. The ray extends from p1 to p1 + maxFraction * (p2 - p1). + /// @param callback a callback class that is called for each proxy that is hit by the ray. + template + void RayCast(T* callback, const b2RayCastInput& input) const; + +private: + + int32 AllocateNode(); + void FreeNode(int32 node); + + void InsertLeaf(int32 node); + void RemoveLeaf(int32 node); + + int32 ComputeHeight(int32 nodeId) const; + + int32 m_root; + + b2DynamicTreeNode* m_nodes; + int32 m_nodeCount; + int32 m_nodeCapacity; + + int32 m_freeList; + + /// This is used incrementally traverse the tree for re-balancing. + uint32 m_path; + + int32 m_insertionCount; +}; + +inline void* b2DynamicTree::GetUserData(int32 proxyId) const +{ + b2Assert(0 <= proxyId && proxyId < m_nodeCapacity); + return m_nodes[proxyId].userData; +} + +inline const b2AABB& b2DynamicTree::GetFatAABB(int32 proxyId) const +{ + b2Assert(0 <= proxyId && proxyId < m_nodeCapacity); + return m_nodes[proxyId].aabb; +} + +template +inline void b2DynamicTree::Query(T* callback, const b2AABB& aabb) const +{ + const int32 k_stackSize = 128; + int32 stack[k_stackSize]; + + int32 count = 0; + stack[count++] = m_root; + + while (count > 0) + { + int32 nodeId = stack[--count]; + if (nodeId == b2_nullNode) + { + continue; + } + + const b2DynamicTreeNode* node = m_nodes + nodeId; + + if (b2TestOverlap(node->aabb, aabb)) + { + if (node->IsLeaf()) + { + bool proceed = callback->QueryCallback(nodeId); + if (proceed == false) + { + return; + } + } + else + { + if (count < k_stackSize) + { + stack[count++] = node->child1; + } + + if (count < k_stackSize) + { + stack[count++] = node->child2; + } + } + } + } +} + +template +inline void b2DynamicTree::RayCast(T* callback, const b2RayCastInput& input) const +{ + b2Vec2 p1 = input.p1; + b2Vec2 p2 = input.p2; + b2Vec2 r = p2 - p1; + b2Assert(r.LengthSquared() > 0.0f); + r.Normalize(); + + // v is perpendicular to the segment. + b2Vec2 v = b2Cross(1.0f, r); + b2Vec2 abs_v = b2Abs(v); + + // Separating axis for segment (Gino, p80). + // |dot(v, p1 - c)| > dot(|v|, h) + + float32 maxFraction = input.maxFraction; + + // Build a bounding box for the segment. + b2AABB segmentAABB; + { + b2Vec2 t = p1 + maxFraction * (p2 - p1); + segmentAABB.lowerBound = b2Min(p1, t); + segmentAABB.upperBound = b2Max(p1, t); + } + + const int32 k_stackSize = 128; + int32 stack[k_stackSize]; + + int32 count = 0; + stack[count++] = m_root; + + while (count > 0) + { + int32 nodeId = stack[--count]; + if (nodeId == b2_nullNode) + { + continue; + } + + const b2DynamicTreeNode* node = m_nodes + nodeId; + + if (b2TestOverlap(node->aabb, segmentAABB) == false) + { + continue; + } + + // Separating axis for segment (Gino, p80). + // |dot(v, p1 - c)| > dot(|v|, h) + b2Vec2 c = node->aabb.GetCenter(); + b2Vec2 h = node->aabb.GetExtents(); + float32 separation = b2Abs(b2Dot(v, p1 - c)) - b2Dot(abs_v, h); + if (separation > 0.0f) + { + continue; + } + + if (node->IsLeaf()) + { + b2RayCastInput subInput; + subInput.p1 = input.p1; + subInput.p2 = input.p2; + subInput.maxFraction = maxFraction; + + float32 value = callback->RayCastCallback(subInput, nodeId); + + if (value == 0.0f) + { + // The client has terminated the ray cast. + return; + } + + if (value > 0.0f) + { + // Update segment bounding box. + maxFraction = value; + b2Vec2 t = p1 + maxFraction * (p2 - p1); + segmentAABB.lowerBound = b2Min(p1, t); + segmentAABB.upperBound = b2Max(p1, t); + } + } + else + { + if (count < k_stackSize) + { + stack[count++] = node->child1; + } + + if (count < k_stackSize) + { + stack[count++] = node->child2; + } + } + } +} + +#endif diff --git a/uppsrc/plugin/box2d/b2Fixture.cpp b/uppsrc/plugin/box2d/b2Fixture.cpp new file mode 100644 index 000000000..3f59b85bb --- /dev/null +++ b/uppsrc/plugin/box2d/b2Fixture.cpp @@ -0,0 +1,163 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Fixture.h" +#include "b2Contact.h" +#include "b2CircleShape.h" +#include "b2PolygonShape.h" +#include "b2BroadPhase.h" +#include "b2Collision.h" +#include "b2BlockAllocator.h" + + +b2Fixture::b2Fixture() +{ + m_userData = NULL; + m_body = NULL; + m_next = NULL; + m_proxyId = b2BroadPhase::e_nullProxy; + m_shape = NULL; + m_density = 0.0f; +} + +b2Fixture::~b2Fixture() +{ + b2Assert(m_shape == NULL); + b2Assert(m_proxyId == b2BroadPhase::e_nullProxy); +} + +void b2Fixture::Create(b2BlockAllocator* allocator, b2Body* body, const b2FixtureDef* def) +{ + m_userData = def->userData; + m_friction = def->friction; + m_restitution = def->restitution; + + m_body = body; + m_next = NULL; + + m_filter = def->filter; + + m_isSensor = def->isSensor; + + m_shape = def->shape->Clone(allocator); + + m_density = def->density; +} + +void b2Fixture::Destroy(b2BlockAllocator* allocator) +{ + // The proxy must be destroyed before calling this. + b2Assert(m_proxyId == b2BroadPhase::e_nullProxy); + + // Free the child shape. + switch (m_shape->m_type) + { + case b2Shape::e_circle: + { + b2CircleShape* s = (b2CircleShape*)m_shape; + s->~b2CircleShape(); + allocator->Free(s, sizeof(b2CircleShape)); + } + break; + + case b2Shape::e_polygon: + { + b2PolygonShape* s = (b2PolygonShape*)m_shape; + s->~b2PolygonShape(); + allocator->Free(s, sizeof(b2PolygonShape)); + } + break; + + default: + b2Assert(false); + break; + } + + m_shape = NULL; +} + +void b2Fixture::CreateProxy(b2BroadPhase* broadPhase, const b2Transform& xf) +{ + b2Assert(m_proxyId == b2BroadPhase::e_nullProxy); + + // Create proxy in the broad-phase. + m_shape->ComputeAABB(&m_aabb, xf); + m_proxyId = broadPhase->CreateProxy(m_aabb, this); +} + +void b2Fixture::DestroyProxy(b2BroadPhase* broadPhase) +{ + if (m_proxyId == b2BroadPhase::e_nullProxy) + { + return; + } + + // Destroy proxy in the broad-phase. + broadPhase->DestroyProxy(m_proxyId); + m_proxyId = b2BroadPhase::e_nullProxy; +} + +void b2Fixture::Synchronize(b2BroadPhase* broadPhase, const b2Transform& transform1, const b2Transform& transform2) +{ + if (m_proxyId == b2BroadPhase::e_nullProxy) + { + return; + } + + // Compute an AABB that covers the swept shape (may miss some rotation effect). + b2AABB aabb1, aabb2; + m_shape->ComputeAABB(&aabb1, transform1); + m_shape->ComputeAABB(&aabb2, transform2); + + m_aabb.Combine(aabb1, aabb2); + + b2Vec2 displacement = transform2.position - transform1.position; + + broadPhase->MoveProxy(m_proxyId, m_aabb, displacement); +} + +void b2Fixture::SetFilterData(const b2Filter& filter) +{ + m_filter = filter; + + if (m_body == NULL) + { + return; + } + + // Flag associated contacts for filtering. + b2ContactEdge* edge = m_body->GetContactList(); + while (edge) + { + b2Contact* contact = edge->contact; + b2Fixture* fixtureA = contact->GetFixtureA(); + b2Fixture* fixtureB = contact->GetFixtureB(); + if (fixtureA == this || fixtureB == this) + { + contact->FlagForFiltering(); + } + + edge = edge->next; + } +} + +void b2Fixture::SetSensor(bool sensor) +{ + m_isSensor = sensor; +} + diff --git a/uppsrc/plugin/box2d/b2Fixture.h b/uppsrc/plugin/box2d/b2Fixture.h new file mode 100644 index 000000000..b6c7d94ec --- /dev/null +++ b/uppsrc/plugin/box2d/b2Fixture.h @@ -0,0 +1,326 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_FIXTURE_H +#define B2_FIXTURE_H + +#include "b2Body.h" +#include "b2Collision.h" +#include "b2Shape.h" + +class b2BlockAllocator; +class b2Body; +class b2BroadPhase; + +/// This holds contact filtering data. +struct b2Filter +{ + /// The collision category bits. Normally you would just set one bit. + uint16 categoryBits; + + /// The collision mask bits. This states the categories that this + /// shape would accept for collision. + uint16 maskBits; + + /// Collision groups allow a certain group of objects to never collide (negative) + /// or always collide (positive). Zero means no collision group. Non-zero group + /// filtering always wins against the mask bits. + int16 groupIndex; +}; + +/// A fixture definition is used to create a fixture. This class defines an +/// abstract fixture definition. You can reuse fixture definitions safely. +struct b2FixtureDef +{ + /// The constructor sets the default fixture definition values. + b2FixtureDef() + { + shape = NULL; + userData = NULL; + friction = 0.2f; + restitution = 0.0f; + density = 0.0f; + filter.categoryBits = 0x0001; + filter.maskBits = 0xFFFF; + filter.groupIndex = 0; + isSensor = false; + } + + virtual ~b2FixtureDef() {} + + /// The shape, this must be set. The shape will be cloned, so you + /// can create the shape on the stack. + const b2Shape* shape; + + /// Use this to store application specific fixture data. + void* userData; + + /// The friction coefficient, usually in the range [0,1]. + float32 friction; + + /// The restitution (elasticity) usually in the range [0,1]. + float32 restitution; + + /// The density, usually in kg/m^2. + float32 density; + + /// A sensor shape collects contact information but never generates a collision + /// response. + bool isSensor; + + /// Contact filtering data. + b2Filter filter; +}; + + +/// A fixture is used to attach a shape to a body for collision detection. A fixture +/// inherits its transform from its parent. Fixtures hold additional non-geometric data +/// such as friction, collision filters, etc. +/// Fixtures are created via b2Body::CreateFixture. +/// @warning you cannot reuse fixtures. +class b2Fixture +{ +public: + /// Get the type of the child shape. You can use this to down cast to the concrete shape. + /// @return the shape type. + b2Shape::Type GetType() const; + + /// Get the child shape. You can modify the child shape, however you should not change the + /// number of vertices because this will crash some collision caching mechanisms. + /// Manipulating the shape may lead to non-physical behavior. + b2Shape* GetShape(); + const b2Shape* GetShape() const; + + /// Set if this fixture is a sensor. + void SetSensor(bool sensor); + + /// Is this fixture a sensor (non-solid)? + /// @return the true if the shape is a sensor. + bool IsSensor() const; + + /// Set the contact filtering data. This will not update contacts until the next time + /// step when either parent body is active and awake. + void SetFilterData(const b2Filter& filter); + + /// Get the contact filtering data. + const b2Filter& GetFilterData() const; + + /// Get the parent body of this fixture. This is NULL if the fixture is not attached. + /// @return the parent body. + b2Body* GetBody(); + const b2Body* GetBody() const; + + /// Get the next fixture in the parent body's fixture list. + /// @return the next shape. + b2Fixture* GetNext(); + const b2Fixture* GetNext() const; + + /// Get the user data that was assigned in the fixture definition. Use this to + /// store your application specific data. + void* GetUserData() const; + + /// Set the user data. Use this to store your application specific data. + void SetUserData(void* data); + + /// Test a point for containment in this fixture. + /// @param xf the shape world transform. + /// @param p a point in world coordinates. + bool TestPoint(const b2Vec2& p) const; + + /// Cast a ray against this shape. + /// @param output the ray-cast results. + /// @param input the ray-cast input parameters. + bool RayCast(b2RayCastOutput* output, const b2RayCastInput& input) const; + + /// Get the mass data for this fixture. The mass data is based on the density and + /// the shape. The rotational inertia is about the shape's origin. This operation + /// may be expensive. + void GetMassData(b2MassData* massData) const; + + /// Set the density of this fixture. This will _not_ automatically adjust the mass + /// of the body. You must call b2Body::ResetMassData to update the body's mass. + void SetDensity(float32 density); + + /// Get the density of this fixture. + float32 GetDensity() const; + + /// Get the coefficient of friction. + float32 GetFriction() const; + + /// Set the coefficient of friction. + void SetFriction(float32 friction); + + /// Get the coefficient of restitution. + float32 GetRestitution() const; + + /// Set the coefficient of restitution. + void SetRestitution(float32 restitution); + + /// Get the fixture's AABB. This AABB may be enlarge and/or stale. + /// If you need a more accurate AABB, compute it using the shape and + /// the body transform. + const b2AABB& GetAABB() const; + +protected: + + friend class b2Body; + friend class b2World; + friend class b2Contact; + friend class b2ContactManager; + + b2Fixture(); + ~b2Fixture(); + + // We need separation create/destroy functions from the constructor/destructor because + // the destructor cannot access the allocator (no destructor arguments allowed by C++). + void Create(b2BlockAllocator* allocator, b2Body* body, const b2FixtureDef* def); + void Destroy(b2BlockAllocator* allocator); + + // These support body activation/deactivation. + void CreateProxy(b2BroadPhase* broadPhase, const b2Transform& xf); + void DestroyProxy(b2BroadPhase* broadPhase); + + void Synchronize(b2BroadPhase* broadPhase, const b2Transform& xf1, const b2Transform& xf2); + + b2AABB m_aabb; + + float32 m_density; + + b2Fixture* m_next; + b2Body* m_body; + + b2Shape* m_shape; + + float32 m_friction; + float32 m_restitution; + + int32 m_proxyId; + b2Filter m_filter; + + bool m_isSensor; + + void* m_userData; +}; + +inline b2Shape::Type b2Fixture::GetType() const +{ + return m_shape->GetType(); +} + +inline b2Shape* b2Fixture::GetShape() +{ + return m_shape; +} + +inline const b2Shape* b2Fixture::GetShape() const +{ + return m_shape; +} + +inline bool b2Fixture::IsSensor() const +{ + return m_isSensor; +} + +inline const b2Filter& b2Fixture::GetFilterData() const +{ + return m_filter; +} + +inline void* b2Fixture::GetUserData() const +{ + return m_userData; +} + +inline void b2Fixture::SetUserData(void* data) +{ + m_userData = data; +} + +inline b2Body* b2Fixture::GetBody() +{ + return m_body; +} + +inline const b2Body* b2Fixture::GetBody() const +{ + return m_body; +} + +inline b2Fixture* b2Fixture::GetNext() +{ + return m_next; +} + +inline const b2Fixture* b2Fixture::GetNext() const +{ + return m_next; +} + +inline void b2Fixture::SetDensity(float32 density) +{ + b2Assert(b2IsValid(density) && density >= 0.0f); + m_density = density; +} + +inline float32 b2Fixture::GetDensity() const +{ + return m_density; +} + +inline float32 b2Fixture::GetFriction() const +{ + return m_friction; +} + +inline void b2Fixture::SetFriction(float32 friction) +{ + m_friction = friction; +} + +inline float32 b2Fixture::GetRestitution() const +{ + return m_restitution; +} + +inline void b2Fixture::SetRestitution(float32 restitution) +{ + m_restitution = restitution; +} + +inline bool b2Fixture::TestPoint(const b2Vec2& p) const +{ + return m_shape->TestPoint(m_body->GetTransform(), p); +} + +inline bool b2Fixture::RayCast(b2RayCastOutput* output, const b2RayCastInput& input) const +{ + return m_shape->RayCast(output, input, m_body->GetTransform()); +} + +inline void b2Fixture::GetMassData(b2MassData* massData) const +{ + m_shape->ComputeMass(massData, m_density); +} + +inline const b2AABB& b2Fixture::GetAABB() const +{ + return m_aabb; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2FrictionJoint.cpp b/uppsrc/plugin/box2d/b2FrictionJoint.cpp new file mode 100644 index 000000000..ab8865b7f --- /dev/null +++ b/uppsrc/plugin/box2d/b2FrictionJoint.cpp @@ -0,0 +1,229 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2FrictionJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// Point-to-point constraint +// Cdot = v2 - v1 +// = v2 + cross(w2, r2) - v1 - cross(w1, r1) +// J = [-I -r1_skew I r2_skew ] +// Identity used: +// w k % (rx i + ry j) = w * (-ry i + rx j) + +// Angle constraint +// Cdot = w2 - w1 +// J = [0 0 -1 0 0 1] +// K = invI1 + invI2 + +void b2FrictionJointDef::Initialize(b2Body* bA, b2Body* bB, const b2Vec2& anchor) +{ + bodyA = bA; + bodyB = bB; + localAnchorA = bodyA->GetLocalPoint(anchor); + localAnchorB = bodyB->GetLocalPoint(anchor); +} + +b2FrictionJoint::b2FrictionJoint(const b2FrictionJointDef* def) +: b2Joint(def) +{ + m_localAnchorA = def->localAnchorA; + m_localAnchorB = def->localAnchorB; + + m_linearImpulse.SetZero(); + m_angularImpulse = 0.0f; + + m_maxForce = def->maxForce; + m_maxTorque = def->maxTorque; +} + +void b2FrictionJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* bA = m_bodyA; + b2Body* bB = m_bodyB; + + // Compute the effective mass matrix. + b2Vec2 rA = b2Mul(bA->GetTransform().R, m_localAnchorA - bA->GetLocalCenter()); + b2Vec2 rB = b2Mul(bB->GetTransform().R, m_localAnchorB - bB->GetLocalCenter()); + + // J = [-I -r1_skew I r2_skew] + // [ 0 -1 0 1] + // r_skew = [-ry; rx] + + // Matlab + // K = [ mA+r1y^2*iA+mB+r2y^2*iB, -r1y*iA*r1x-r2y*iB*r2x, -r1y*iA-r2y*iB] + // [ -r1y*iA*r1x-r2y*iB*r2x, mA+r1x^2*iA+mB+r2x^2*iB, r1x*iA+r2x*iB] + // [ -r1y*iA-r2y*iB, r1x*iA+r2x*iB, iA+iB] + + float32 mA = bA->m_invMass, mB = bB->m_invMass; + float32 iA = bA->m_invI, iB = bB->m_invI; + + b2Mat22 K1; + K1.col1.x = mA + mB; K1.col2.x = 0.0f; + K1.col1.y = 0.0f; K1.col2.y = mA + mB; + + b2Mat22 K2; + K2.col1.x = iA * rA.y * rA.y; K2.col2.x = -iA * rA.x * rA.y; + K2.col1.y = -iA * rA.x * rA.y; K2.col2.y = iA * rA.x * rA.x; + + b2Mat22 K3; + K3.col1.x = iB * rB.y * rB.y; K3.col2.x = -iB * rB.x * rB.y; + K3.col1.y = -iB * rB.x * rB.y; K3.col2.y = iB * rB.x * rB.x; + + b2Mat22 K = K1 + K2 + K3; + m_linearMass = K.GetInverse(); + + m_angularMass = iA + iB; + if (m_angularMass > 0.0f) + { + m_angularMass = 1.0f / m_angularMass; + } + + if (step.warmStarting) + { + // Scale impulses to support a variable time step. + m_linearImpulse *= step.dtRatio; + m_angularImpulse *= step.dtRatio; + + b2Vec2 P(m_linearImpulse.x, m_linearImpulse.y); + + bA->m_linearVelocity -= mA * P; + bA->m_angularVelocity -= iA * (b2Cross(rA, P) + m_angularImpulse); + + bB->m_linearVelocity += mB * P; + bB->m_angularVelocity += iB * (b2Cross(rB, P) + m_angularImpulse); + } + else + { + m_linearImpulse.SetZero(); + m_angularImpulse = 0.0f; + } +} + +void b2FrictionJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + B2_NOT_USED(step); + + b2Body* bA = m_bodyA; + b2Body* bB = m_bodyB; + + b2Vec2 vA = bA->m_linearVelocity; + float32 wA = bA->m_angularVelocity; + b2Vec2 vB = bB->m_linearVelocity; + float32 wB = bB->m_angularVelocity; + + float32 mA = bA->m_invMass, mB = bB->m_invMass; + float32 iA = bA->m_invI, iB = bB->m_invI; + + b2Vec2 rA = b2Mul(bA->GetTransform().R, m_localAnchorA - bA->GetLocalCenter()); + b2Vec2 rB = b2Mul(bB->GetTransform().R, m_localAnchorB - bB->GetLocalCenter()); + + // Solve angular friction + { + float32 Cdot = wB - wA; + float32 impulse = -m_angularMass * Cdot; + + float32 oldImpulse = m_angularImpulse; + float32 maxImpulse = step.dt * m_maxTorque; + m_angularImpulse = b2Clamp(m_angularImpulse + impulse, -maxImpulse, maxImpulse); + impulse = m_angularImpulse - oldImpulse; + + wA -= iA * impulse; + wB += iB * impulse; + } + + // Solve linear friction + { + b2Vec2 Cdot = vB + b2Cross(wB, rB) - vA - b2Cross(wA, rA); + + b2Vec2 impulse = -b2Mul(m_linearMass, Cdot); + b2Vec2 oldImpulse = m_linearImpulse; + m_linearImpulse += impulse; + + float32 maxImpulse = step.dt * m_maxForce; + + if (m_linearImpulse.LengthSquared() > maxImpulse * maxImpulse) + { + m_linearImpulse.Normalize(); + m_linearImpulse *= maxImpulse; + } + + impulse = m_linearImpulse - oldImpulse; + + vA -= mA * impulse; + wA -= iA * b2Cross(rA, impulse); + + vB += mB * impulse; + wB += iB * b2Cross(rB, impulse); + } + + bA->m_linearVelocity = vA; + bA->m_angularVelocity = wA; + bB->m_linearVelocity = vB; + bB->m_angularVelocity = wB; +} + +bool b2FrictionJoint::SolvePositionConstraints(float32 baumgarte) +{ + B2_NOT_USED(baumgarte); + + return true; +} + +b2Vec2 b2FrictionJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchorA); +} + +b2Vec2 b2FrictionJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchorB); +} + +b2Vec2 b2FrictionJoint::GetReactionForce(float32 inv_dt) const +{ + return inv_dt * m_linearImpulse; +} + +float32 b2FrictionJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_angularImpulse; +} + +void b2FrictionJoint::SetMaxForce(float32 force) +{ + b2Assert(b2IsValid(force) && force >= 0.0f); + m_maxForce = force; +} + +float32 b2FrictionJoint::GetMaxForce() const +{ + return m_maxForce; +} + +void b2FrictionJoint::SetMaxTorque(float32 torque) +{ + b2Assert(b2IsValid(torque) && torque >= 0.0f); + m_maxTorque = torque; +} + +float32 b2FrictionJoint::GetMaxTorque() const +{ + return m_maxTorque; +} diff --git a/uppsrc/plugin/box2d/b2FrictionJoint.h b/uppsrc/plugin/box2d/b2FrictionJoint.h new file mode 100644 index 000000000..d914c24e9 --- /dev/null +++ b/uppsrc/plugin/box2d/b2FrictionJoint.h @@ -0,0 +1,99 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_FRICTION_JOINT_H +#define B2_FRICTION_JOINT_H + +#include "b2Joint.h" + +/// Friction joint definition. +struct b2FrictionJointDef : public b2JointDef +{ + b2FrictionJointDef() + { + type = e_frictionJoint; + localAnchorA.SetZero(); + localAnchorB.SetZero(); + maxForce = 0.0f; + maxTorque = 0.0f; + } + + /// Initialize the bodies, anchors, axis, and reference angle using the world + /// anchor and world axis. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor); + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The maximum friction force in N. + float32 maxForce; + + /// The maximum friction torque in N-m. + float32 maxTorque; +}; + +/// Friction joint. This is used for top-down friction. +/// It provides 2D translational friction and angular friction. +class b2FrictionJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const; + b2Vec2 GetAnchorB() const; + + b2Vec2 GetReactionForce(float32 inv_dt) const; + float32 GetReactionTorque(float32 inv_dt) const; + + /// Set the maximum friction force in N. + void SetMaxForce(float32 force); + + /// Get the maximum friction force in N. + float32 GetMaxForce() const; + + /// Set the maximum friction torque in N*m. + void SetMaxTorque(float32 torque); + + /// Get the maximum friction torque in N*m. + float32 GetMaxTorque() const; + +protected: + + friend class b2Joint; + + b2FrictionJoint(const b2FrictionJointDef* def); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + bool SolvePositionConstraints(float32 baumgarte); + + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + + b2Mat22 m_linearMass; + float32 m_angularMass; + + b2Vec2 m_linearImpulse; + float32 m_angularImpulse; + + float32 m_maxForce; + float32 m_maxTorque; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2GearJoint.cpp b/uppsrc/plugin/box2d/b2GearJoint.cpp new file mode 100644 index 000000000..ada246b40 --- /dev/null +++ b/uppsrc/plugin/box2d/b2GearJoint.cpp @@ -0,0 +1,259 @@ +/* +* Copyright (c) 2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2GearJoint.h" +#include "b2RevoluteJoint.h" +#include "b2PrismaticJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// Gear Joint: +// C0 = (coordinate1 + ratio * coordinate2)_initial +// C = C0 - (cordinate1 + ratio * coordinate2) = 0 +// Cdot = -(Cdot1 + ratio * Cdot2) +// J = -[J1 ratio * J2] +// K = J * invM * JT +// = J1 * invM1 * J1T + ratio * ratio * J2 * invM2 * J2T +// +// Revolute: +// coordinate = rotation +// Cdot = angularVelocity +// J = [0 0 1] +// K = J * invM * JT = invI +// +// Prismatic: +// coordinate = dot(p - pg, ug) +// Cdot = dot(v + cross(w, r), ug) +// J = [ug cross(r, ug)] +// K = J * invM * JT = invMass + invI * cross(r, ug)^2 + +b2GearJoint::b2GearJoint(const b2GearJointDef* def) +: b2Joint(def) +{ + b2JointType type1 = def->joint1->GetType(); + b2JointType type2 = def->joint2->GetType(); + + b2Assert(type1 == e_revoluteJoint || type1 == e_prismaticJoint); + b2Assert(type2 == e_revoluteJoint || type2 == e_prismaticJoint); + b2Assert(def->joint1->GetBodyA()->GetType() == b2_staticBody); + b2Assert(def->joint2->GetBodyA()->GetType() == b2_staticBody); + + m_revolute1 = NULL; + m_prismatic1 = NULL; + m_revolute2 = NULL; + m_prismatic2 = NULL; + + float32 coordinate1, coordinate2; + + m_ground1 = def->joint1->GetBodyA(); + m_bodyA = def->joint1->GetBodyB(); + if (type1 == e_revoluteJoint) + { + m_revolute1 = (b2RevoluteJoint*)def->joint1; + m_groundAnchor1 = m_revolute1->m_localAnchor1; + m_localAnchor1 = m_revolute1->m_localAnchor2; + coordinate1 = m_revolute1->GetJointAngle(); + } + else + { + m_prismatic1 = (b2PrismaticJoint*)def->joint1; + m_groundAnchor1 = m_prismatic1->m_localAnchor1; + m_localAnchor1 = m_prismatic1->m_localAnchor2; + coordinate1 = m_prismatic1->GetJointTranslation(); + } + + m_ground2 = def->joint2->GetBodyA(); + m_bodyB = def->joint2->GetBodyB(); + if (type2 == e_revoluteJoint) + { + m_revolute2 = (b2RevoluteJoint*)def->joint2; + m_groundAnchor2 = m_revolute2->m_localAnchor1; + m_localAnchor2 = m_revolute2->m_localAnchor2; + coordinate2 = m_revolute2->GetJointAngle(); + } + else + { + m_prismatic2 = (b2PrismaticJoint*)def->joint2; + m_groundAnchor2 = m_prismatic2->m_localAnchor1; + m_localAnchor2 = m_prismatic2->m_localAnchor2; + coordinate2 = m_prismatic2->GetJointTranslation(); + } + + m_ratio = def->ratio; + + m_constant = coordinate1 + m_ratio * coordinate2; + + m_impulse = 0.0f; +} + +void b2GearJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* g1 = m_ground1; + b2Body* g2 = m_ground2; + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + float32 K = 0.0f; + m_J.SetZero(); + + if (m_revolute1) + { + m_J.angularA = -1.0f; + K += b1->m_invI; + } + else + { + b2Vec2 ug = b2Mul(g1->GetTransform().R, m_prismatic1->m_localXAxis1); + b2Vec2 r = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + float32 crug = b2Cross(r, ug); + m_J.linearA = -ug; + m_J.angularA = -crug; + K += b1->m_invMass + b1->m_invI * crug * crug; + } + + if (m_revolute2) + { + m_J.angularB = -m_ratio; + K += m_ratio * m_ratio * b2->m_invI; + } + else + { + b2Vec2 ug = b2Mul(g2->GetTransform().R, m_prismatic2->m_localXAxis1); + b2Vec2 r = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + float32 crug = b2Cross(r, ug); + m_J.linearB = -m_ratio * ug; + m_J.angularB = -m_ratio * crug; + K += m_ratio * m_ratio * (b2->m_invMass + b2->m_invI * crug * crug); + } + + // Compute effective mass. + m_mass = K > 0.0f ? 1.0f / K : 0.0f; + + if (step.warmStarting) + { + // Warm starting. + b1->m_linearVelocity += b1->m_invMass * m_impulse * m_J.linearA; + b1->m_angularVelocity += b1->m_invI * m_impulse * m_J.angularA; + b2->m_linearVelocity += b2->m_invMass * m_impulse * m_J.linearB; + b2->m_angularVelocity += b2->m_invI * m_impulse * m_J.angularB; + } + else + { + m_impulse = 0.0f; + } +} + +void b2GearJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + B2_NOT_USED(step); + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + float32 Cdot = m_J.Compute( b1->m_linearVelocity, b1->m_angularVelocity, + b2->m_linearVelocity, b2->m_angularVelocity); + + float32 impulse = m_mass * (-Cdot); + m_impulse += impulse; + + b1->m_linearVelocity += b1->m_invMass * impulse * m_J.linearA; + b1->m_angularVelocity += b1->m_invI * impulse * m_J.angularA; + b2->m_linearVelocity += b2->m_invMass * impulse * m_J.linearB; + b2->m_angularVelocity += b2->m_invI * impulse * m_J.angularB; +} + +bool b2GearJoint::SolvePositionConstraints(float32 baumgarte) +{ + B2_NOT_USED(baumgarte); + + float32 linearError = 0.0f; + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + float32 coordinate1, coordinate2; + if (m_revolute1) + { + coordinate1 = m_revolute1->GetJointAngle(); + } + else + { + coordinate1 = m_prismatic1->GetJointTranslation(); + } + + if (m_revolute2) + { + coordinate2 = m_revolute2->GetJointAngle(); + } + else + { + coordinate2 = m_prismatic2->GetJointTranslation(); + } + + float32 C = m_constant - (coordinate1 + m_ratio * coordinate2); + + float32 impulse = m_mass * (-C); + + b1->m_sweep.c += b1->m_invMass * impulse * m_J.linearA; + b1->m_sweep.a += b1->m_invI * impulse * m_J.angularA; + b2->m_sweep.c += b2->m_invMass * impulse * m_J.linearB; + b2->m_sweep.a += b2->m_invI * impulse * m_J.angularB; + + b1->SynchronizeTransform(); + b2->SynchronizeTransform(); + + // TODO_ERIN not implemented + return linearError < b2_linearSlop; +} + +b2Vec2 b2GearJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchor1); +} + +b2Vec2 b2GearJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchor2); +} + +b2Vec2 b2GearJoint::GetReactionForce(float32 inv_dt) const +{ + // TODO_ERIN not tested + b2Vec2 P = m_impulse * m_J.linearB; + return inv_dt * P; +} + +float32 b2GearJoint::GetReactionTorque(float32 inv_dt) const +{ + // TODO_ERIN not tested + b2Vec2 r = b2Mul(m_bodyB->GetTransform().R, m_localAnchor2 - m_bodyB->GetLocalCenter()); + b2Vec2 P = m_impulse * m_J.linearB; + float32 L = m_impulse * m_J.angularB - b2Cross(r, P); + return inv_dt * L; +} + +void b2GearJoint::SetRatio(float32 ratio) +{ + b2Assert(b2IsValid(ratio)); + m_ratio = ratio; +} + +float32 b2GearJoint::GetRatio() const +{ + return m_ratio; +} diff --git a/uppsrc/plugin/box2d/b2GearJoint.h b/uppsrc/plugin/box2d/b2GearJoint.h new file mode 100644 index 000000000..4f00e3660 --- /dev/null +++ b/uppsrc/plugin/box2d/b2GearJoint.h @@ -0,0 +1,111 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_GEAR_JOINT_H +#define B2_GEAR_JOINT_H + +#include "b2Joint.h" + +class b2RevoluteJoint; +class b2PrismaticJoint; + +/// Gear joint definition. This definition requires two existing +/// revolute or prismatic joints (any combination will work). +/// The provided joints must attach a dynamic body to a static body. +struct b2GearJointDef : public b2JointDef +{ + b2GearJointDef() + { + type = e_gearJoint; + joint1 = NULL; + joint2 = NULL; + ratio = 1.0f; + } + + /// The first revolute/prismatic joint attached to the gear joint. + b2Joint* joint1; + + /// The second revolute/prismatic joint attached to the gear joint. + b2Joint* joint2; + + /// The gear ratio. + /// @see b2GearJoint for explanation. + float32 ratio; +}; + +/// A gear joint is used to connect two joints together. Either joint +/// can be a revolute or prismatic joint. You specify a gear ratio +/// to bind the motions together: +/// coordinate1 + ratio * coordinate2 = constant +/// The ratio can be negative or positive. If one joint is a revolute joint +/// and the other joint is a prismatic joint, then the ratio will have units +/// of length or units of 1/length. +/// @warning The revolute and prismatic joints must be attached to +/// fixed bodies (which must be body1 on those joints). +class b2GearJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const; + b2Vec2 GetAnchorB() const; + + b2Vec2 GetReactionForce(float32 inv_dt) const; + float32 GetReactionTorque(float32 inv_dt) const; + + /// Set/Get the gear ratio. + void SetRatio(float32 ratio); + float32 GetRatio() const; + +protected: + + friend class b2Joint; + b2GearJoint(const b2GearJointDef* data); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + bool SolvePositionConstraints(float32 baumgarte); + + b2Body* m_ground1; + b2Body* m_ground2; + + // One of these is NULL. + b2RevoluteJoint* m_revolute1; + b2PrismaticJoint* m_prismatic1; + + // One of these is NULL. + b2RevoluteJoint* m_revolute2; + b2PrismaticJoint* m_prismatic2; + + b2Vec2 m_groundAnchor1; + b2Vec2 m_groundAnchor2; + + b2Vec2 m_localAnchor1; + b2Vec2 m_localAnchor2; + + b2Jacobian m_J; + + float32 m_constant; + float32 m_ratio; + + // Effective mass + float32 m_mass; + + // Impulse for accumulation/warm starting. + float32 m_impulse; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2Island.cpp b/uppsrc/plugin/box2d/b2Island.cpp new file mode 100644 index 000000000..a7abd1f5f --- /dev/null +++ b/uppsrc/plugin/box2d/b2Island.cpp @@ -0,0 +1,374 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Island.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2World.h" +#include "b2Contact.h" +#include "b2ContactSolver.h" +#include "b2Joint.h" +#include "b2StackAllocator.h" + +/* +Position Correction Notes +========================= +I tried the several algorithms for position correction of the 2D revolute joint. +I looked at these systems: +- simple pendulum (1m diameter sphere on massless 5m stick) with initial angular velocity of 100 rad/s. +- suspension bridge with 30 1m long planks of length 1m. +- multi-link chain with 30 1m long links. + +Here are the algorithms: + +Baumgarte - A fraction of the position error is added to the velocity error. There is no +separate position solver. + +Pseudo Velocities - After the velocity solver and position integration, +the position error, Jacobian, and effective mass are recomputed. Then +the velocity constraints are solved with pseudo velocities and a fraction +of the position error is added to the pseudo velocity error. The pseudo +velocities are initialized to zero and there is no warm-starting. After +the position solver, the pseudo velocities are added to the positions. +This is also called the First Order World method or the Position LCP method. + +Modified Nonlinear Gauss-Seidel (NGS) - Like Pseudo Velocities except the +position error is re-computed for each constraint and the positions are updated +after the constraint is solved. The radius vectors (aka Jacobians) are +re-computed too (otherwise the algorithm has horrible instability). The pseudo +velocity states are not needed because they are effectively zero at the beginning +of each iteration. Since we have the current position error, we allow the +iterations to terminate early if the error becomes smaller than b2_linearSlop. + +Full NGS or just NGS - Like Modified NGS except the effective mass are re-computed +each time a constraint is solved. + +Here are the results: +Baumgarte - this is the cheapest algorithm but it has some stability problems, +especially with the bridge. The chain links separate easily close to the root +and they jitter as they struggle to pull together. This is one of the most common +methods in the field. The big drawback is that the position correction artificially +affects the momentum, thus leading to instabilities and false bounce. I used a +bias factor of 0.2. A larger bias factor makes the bridge less stable, a smaller +factor makes joints and contacts more spongy. + +Pseudo Velocities - the is more stable than the Baumgarte method. The bridge is +stable. However, joints still separate with large angular velocities. Drag the +simple pendulum in a circle quickly and the joint will separate. The chain separates +easily and does not recover. I used a bias factor of 0.2. A larger value lead to +the bridge collapsing when a heavy cube drops on it. + +Modified NGS - this algorithm is better in some ways than Baumgarte and Pseudo +Velocities, but in other ways it is worse. The bridge and chain are much more +stable, but the simple pendulum goes unstable at high angular velocities. + +Full NGS - stable in all tests. The joints display good stiffness. The bridge +still sags, but this is better than infinite forces. + +Recommendations +Pseudo Velocities are not really worthwhile because the bridge and chain cannot +recover from joint separation. In other cases the benefit over Baumgarte is small. + +Modified NGS is not a robust method for the revolute joint due to the violent +instability seen in the simple pendulum. Perhaps it is viable with other constraint +types, especially scalar constraints where the effective mass is a scalar. + +This leaves Baumgarte and Full NGS. Baumgarte has small, but manageable instabilities +and is very fast. I don't think we can escape Baumgarte, especially in highly +demanding cases where high constraint fidelity is not needed. + +Full NGS is robust and easy on the eyes. I recommend this as an option for +higher fidelity simulation and certainly for suspension bridges and long chains. +Full NGS might be a good choice for ragdolls, especially motorized ragdolls where +joint separation can be problematic. The number of NGS iterations can be reduced +for better performance without harming robustness much. + +Each joint in a can be handled differently in the position solver. So I recommend +a system where the user can select the algorithm on a per joint basis. I would +probably default to the slower Full NGS and let the user select the faster +Baumgarte method in performance critical scenarios. +*/ + +/* +Cache Performance + +The Box2D solvers are dominated by cache misses. Data structures are designed +to increase the number of cache hits. Much of misses are due to random access +to body data. The constraint structures are iterated over linearly, which leads +to few cache misses. + +The bodies are not accessed during iteration. Instead read only data, such as +the mass values are stored with the constraints. The mutable data are the constraint +impulses and the bodies velocities/positions. The impulses are held inside the +constraint structures. The body velocities/positions are held in compact, temporary +arrays to increase the number of cache hits. Linear and angular velocity are +stored in a single array since multiple arrays lead to multiple misses. +*/ + +/* +2D Rotation + +R = [cos(theta) -sin(theta)] + [sin(theta) cos(theta) ] + +thetaDot = omega + +Let q1 = cos(theta), q2 = sin(theta). +R = [q1 -q2] + [q2 q1] + +q1Dot = -thetaDot * q2 +q2Dot = thetaDot * q1 + +q1_new = q1_old - dt * w * q2 +q2_new = q2_old + dt * w * q1 +then normalize. + +This might be faster than computing sin+cos. +However, we can compute sin+cos of the same angle fast. +*/ + +b2Island::b2Island( + int32 bodyCapacity, + int32 contactCapacity, + int32 jointCapacity, + b2StackAllocator* allocator, + b2ContactListener* listener) +{ + m_bodyCapacity = bodyCapacity; + m_contactCapacity = contactCapacity; + m_jointCapacity = jointCapacity; + m_bodyCount = 0; + m_contactCount = 0; + m_jointCount = 0; + + m_allocator = allocator; + m_listener = listener; + + m_bodies = (b2Body**)m_allocator->Allocate(bodyCapacity * sizeof(b2Body*)); + m_contacts = (b2Contact**)m_allocator->Allocate(contactCapacity * sizeof(b2Contact*)); + m_joints = (b2Joint**)m_allocator->Allocate(jointCapacity * sizeof(b2Joint*)); + + m_velocities = (b2Velocity*)m_allocator->Allocate(m_bodyCapacity * sizeof(b2Velocity)); + m_positions = (b2Position*)m_allocator->Allocate(m_bodyCapacity * sizeof(b2Position)); +} + +b2Island::~b2Island() +{ + // Warning: the order should reverse the constructor order. + m_allocator->Free(m_positions); + m_allocator->Free(m_velocities); + m_allocator->Free(m_joints); + m_allocator->Free(m_contacts); + m_allocator->Free(m_bodies); +} + +void b2Island::Solve(const b2TimeStep& step, const b2Vec2& gravity, bool allowSleep) +{ + // Integrate velocities and apply damping. + for (int32 i = 0; i < m_bodyCount; ++i) + { + b2Body* b = m_bodies[i]; + + if (b->GetType() != b2_dynamicBody) + { + continue; + } + + // Integrate velocities. + b->m_linearVelocity += step.dt * (gravity + b->m_invMass * b->m_force); + b->m_angularVelocity += step.dt * b->m_invI * b->m_torque; + + // Apply damping. + // ODE: dv/dt + c * v = 0 + // Solution: v(t) = v0 * exp(-c * t) + // Time step: v(t + dt) = v0 * exp(-c * (t + dt)) = v0 * exp(-c * t) * exp(-c * dt) = v * exp(-c * dt) + // v2 = exp(-c * dt) * v1 + // Taylor expansion: + // v2 = (1.0f - c * dt) * v1 + b->m_linearVelocity *= b2Clamp(1.0f - step.dt * b->m_linearDamping, 0.0f, 1.0f); + b->m_angularVelocity *= b2Clamp(1.0f - step.dt * b->m_angularDamping, 0.0f, 1.0f); + } + + // Partition contacts so that contacts with static bodies are solved last. + int32 i1 = -1; + for (int32 i2 = 0; i2 < m_contactCount; ++i2) + { + b2Fixture* fixtureA = m_contacts[i2]->GetFixtureA(); + b2Fixture* fixtureB = m_contacts[i2]->GetFixtureB(); + b2Body* bodyA = fixtureA->GetBody(); + b2Body* bodyB = fixtureB->GetBody(); + bool nonStatic = bodyA->GetType() != b2_staticBody && bodyB->GetType() != b2_staticBody; + if (nonStatic) + { + ++i1; + b2Swap(m_contacts[i1], m_contacts[i2]); + } + } + + // Initialize velocity constraints. + b2ContactSolver contactSolver(m_contacts, m_contactCount, m_allocator, step.dtRatio); + contactSolver.WarmStart(); + for (int32 i = 0; i < m_jointCount; ++i) + { + m_joints[i]->InitVelocityConstraints(step); + } + + // Solve velocity constraints. + for (int32 i = 0; i < step.velocityIterations; ++i) + { + for (int32 j = 0; j < m_jointCount; ++j) + { + m_joints[j]->SolveVelocityConstraints(step); + } + + contactSolver.SolveVelocityConstraints(); + } + + // Post-solve (store impulses for warm starting). + contactSolver.StoreImpulses(); + + // Integrate positions. + for (int32 i = 0; i < m_bodyCount; ++i) + { + b2Body* b = m_bodies[i]; + + if (b->GetType() == b2_staticBody) + { + continue; + } + + // Check for large velocities. + b2Vec2 translation = step.dt * b->m_linearVelocity; + if (b2Dot(translation, translation) > b2_maxTranslationSquared) + { + float32 ratio = b2_maxTranslation / translation.Length(); + b->m_linearVelocity *= ratio; + } + + float32 rotation = step.dt * b->m_angularVelocity; + if (rotation * rotation > b2_maxRotationSquared) + { + float32 ratio = b2_maxRotation / b2Abs(rotation); + b->m_angularVelocity *= ratio; + } + + // Store positions for continuous collision. + b->m_sweep.c0 = b->m_sweep.c; + b->m_sweep.a0 = b->m_sweep.a; + + // Integrate + b->m_sweep.c += step.dt * b->m_linearVelocity; + b->m_sweep.a += step.dt * b->m_angularVelocity; + + // Compute new transform + b->SynchronizeTransform(); + + // Note: shapes are synchronized later. + } + + // Iterate over constraints. + for (int32 i = 0; i < step.positionIterations; ++i) + { + bool contactsOkay = contactSolver.SolvePositionConstraints(b2_contactBaumgarte); + + bool jointsOkay = true; + for (int32 i = 0; i < m_jointCount; ++i) + { + bool jointOkay = m_joints[i]->SolvePositionConstraints(b2_contactBaumgarte); + jointsOkay = jointsOkay && jointOkay; + } + + if (contactsOkay && jointsOkay) + { + // Exit early if the position errors are small. + break; + } + } + + Report(contactSolver.m_constraints); + + if (allowSleep) + { + float32 minSleepTime = b2_maxFloat; + + const float32 linTolSqr = b2_linearSleepTolerance * b2_linearSleepTolerance; + const float32 angTolSqr = b2_angularSleepTolerance * b2_angularSleepTolerance; + + for (int32 i = 0; i < m_bodyCount; ++i) + { + b2Body* b = m_bodies[i]; + if (b->GetType() == b2_staticBody) + { + continue; + } + + if ((b->m_flags & b2Body::e_autoSleepFlag) == 0) + { + b->m_sleepTime = 0.0f; + minSleepTime = 0.0f; + } + + if ((b->m_flags & b2Body::e_autoSleepFlag) == 0 || + b->m_angularVelocity * b->m_angularVelocity > angTolSqr || + b2Dot(b->m_linearVelocity, b->m_linearVelocity) > linTolSqr) + { + b->m_sleepTime = 0.0f; + minSleepTime = 0.0f; + } + else + { + b->m_sleepTime += step.dt; + minSleepTime = b2Min(minSleepTime, b->m_sleepTime); + } + } + + if (minSleepTime >= b2_timeToSleep) + { + for (int32 i = 0; i < m_bodyCount; ++i) + { + b2Body* b = m_bodies[i]; + b->SetAwake(false); + } + } + } +} + +void b2Island::Report(const b2ContactConstraint* constraints) +{ + if (m_listener == NULL) + { + return; + } + + for (int32 i = 0; i < m_contactCount; ++i) + { + b2Contact* c = m_contacts[i]; + + const b2ContactConstraint* cc = constraints + i; + + b2ContactImpulse impulse; + for (int32 j = 0; j < cc->pointCount; ++j) + { + impulse.normalImpulses[j] = cc->points[j].normalImpulse; + impulse.tangentImpulses[j] = cc->points[j].tangentImpulse; + } + + m_listener->PostSolve(c, &impulse); + } +} diff --git a/uppsrc/plugin/box2d/b2Island.h b/uppsrc/plugin/box2d/b2Island.h new file mode 100644 index 000000000..e1731f527 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Island.h @@ -0,0 +1,105 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_ISLAND_H +#define B2_ISLAND_H + +#include "b2Math.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +class b2Contact; +class b2Joint; +class b2StackAllocator; +class b2ContactListener; +struct b2ContactConstraint; + +/// This is an internal structure. +struct b2Position +{ + b2Vec2 x; + float32 a; +}; + +/// This is an internal structure. +struct b2Velocity +{ + b2Vec2 v; + float32 w; +}; + +/// This is an internal class. +class b2Island +{ +public: + b2Island(int32 bodyCapacity, int32 contactCapacity, int32 jointCapacity, + b2StackAllocator* allocator, b2ContactListener* listener); + ~b2Island(); + + void Clear() + { + m_bodyCount = 0; + m_contactCount = 0; + m_jointCount = 0; + } + + void Solve(const b2TimeStep& step, const b2Vec2& gravity, bool allowSleep); + + void Add(b2Body* body) + { + b2Assert(m_bodyCount < m_bodyCapacity); + body->m_islandIndex = m_bodyCount; + m_bodies[m_bodyCount++] = body; + } + + void Add(b2Contact* contact) + { + b2Assert(m_contactCount < m_contactCapacity); + m_contacts[m_contactCount++] = contact; + } + + void Add(b2Joint* joint) + { + b2Assert(m_jointCount < m_jointCapacity); + m_joints[m_jointCount++] = joint; + } + + void Report(const b2ContactConstraint* constraints); + + b2StackAllocator* m_allocator; + b2ContactListener* m_listener; + + b2Body** m_bodies; + b2Contact** m_contacts; + b2Joint** m_joints; + + b2Position* m_positions; + b2Velocity* m_velocities; + + int32 m_bodyCount; + int32 m_jointCount; + int32 m_contactCount; + + int32 m_bodyCapacity; + int32 m_contactCapacity; + int32 m_jointCapacity; + + int32 m_positionIterationCount; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2Joint.cpp b/uppsrc/plugin/box2d/b2Joint.cpp new file mode 100644 index 000000000..c2a6219db --- /dev/null +++ b/uppsrc/plugin/box2d/b2Joint.cpp @@ -0,0 +1,186 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Joint.h" +#include "b2DistanceJoint.h" +#include "b2LineJoint.h" +#include "b2MouseJoint.h" +#include "b2RevoluteJoint.h" +#include "b2PrismaticJoint.h" +#include "b2PulleyJoint.h" +#include "b2GearJoint.h" +#include "b2WeldJoint.h" +#include "b2FrictionJoint.h" +#include "b2Body.h" +#include "b2World.h" +#include "b2BlockAllocator.h" + +#include + +b2Joint* b2Joint::Create(const b2JointDef* def, b2BlockAllocator* allocator) +{ + b2Joint* joint = NULL; + + switch (def->type) + { + case e_distanceJoint: + { + void* mem = allocator->Allocate(sizeof(b2DistanceJoint)); + joint = new (mem) b2DistanceJoint((b2DistanceJointDef*)def); + } + break; + + case e_mouseJoint: + { + void* mem = allocator->Allocate(sizeof(b2MouseJoint)); + joint = new (mem) b2MouseJoint((b2MouseJointDef*)def); + } + break; + + case e_prismaticJoint: + { + void* mem = allocator->Allocate(sizeof(b2PrismaticJoint)); + joint = new (mem) b2PrismaticJoint((b2PrismaticJointDef*)def); + } + break; + + case e_revoluteJoint: + { + void* mem = allocator->Allocate(sizeof(b2RevoluteJoint)); + joint = new (mem) b2RevoluteJoint((b2RevoluteJointDef*)def); + } + break; + + case e_pulleyJoint: + { + void* mem = allocator->Allocate(sizeof(b2PulleyJoint)); + joint = new (mem) b2PulleyJoint((b2PulleyJointDef*)def); + } + break; + + case e_gearJoint: + { + void* mem = allocator->Allocate(sizeof(b2GearJoint)); + joint = new (mem) b2GearJoint((b2GearJointDef*)def); + } + break; + + case e_lineJoint: + { + void* mem = allocator->Allocate(sizeof(b2LineJoint)); + joint = new (mem) b2LineJoint((b2LineJointDef*)def); + } + break; + + case e_weldJoint: + { + void* mem = allocator->Allocate(sizeof(b2WeldJoint)); + joint = new (mem) b2WeldJoint((b2WeldJointDef*)def); + } + break; + + case e_frictionJoint: + { + void* mem = allocator->Allocate(sizeof(b2FrictionJoint)); + joint = new (mem) b2FrictionJoint((b2FrictionJointDef*)def); + } + break; + + default: + b2Assert(false); + break; + } + + return joint; +} + +void b2Joint::Destroy(b2Joint* joint, b2BlockAllocator* allocator) +{ + joint->~b2Joint(); + switch (joint->m_type) + { + case e_distanceJoint: + allocator->Free(joint, sizeof(b2DistanceJoint)); + break; + + case e_mouseJoint: + allocator->Free(joint, sizeof(b2MouseJoint)); + break; + + case e_prismaticJoint: + allocator->Free(joint, sizeof(b2PrismaticJoint)); + break; + + case e_revoluteJoint: + allocator->Free(joint, sizeof(b2RevoluteJoint)); + break; + + case e_pulleyJoint: + allocator->Free(joint, sizeof(b2PulleyJoint)); + break; + + case e_gearJoint: + allocator->Free(joint, sizeof(b2GearJoint)); + break; + + case e_lineJoint: + allocator->Free(joint, sizeof(b2LineJoint)); + break; + + case e_weldJoint: + allocator->Free(joint, sizeof(b2WeldJoint)); + break; + + case e_frictionJoint: + allocator->Free(joint, sizeof(b2FrictionJoint)); + break; + + default: + b2Assert(false); + break; + } +} + +b2Joint::b2Joint(const b2JointDef* def) +{ + b2Assert(def->bodyA != def->bodyB); + + m_type = def->type; + m_prev = NULL; + m_next = NULL; + m_bodyA = def->bodyA; + m_bodyB = def->bodyB; + m_collideConnected = def->collideConnected; + m_islandFlag = false; + m_userData = def->userData; + + m_edgeA.joint = NULL; + m_edgeA.other = NULL; + m_edgeA.prev = NULL; + m_edgeA.next = NULL; + + m_edgeB.joint = NULL; + m_edgeB.other = NULL; + m_edgeB.prev = NULL; + m_edgeB.next = NULL; +} + +bool b2Joint::IsActive() const +{ + return m_bodyA->IsActive() && m_bodyB->IsActive(); +} diff --git a/uppsrc/plugin/box2d/b2Joint.h b/uppsrc/plugin/box2d/b2Joint.h new file mode 100644 index 000000000..c3ac1ccf0 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Joint.h @@ -0,0 +1,226 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_JOINT_H +#define B2_JOINT_H + +#include "b2Math.h" + +class b2Body; +class b2Joint; +struct b2TimeStep; +class b2BlockAllocator; + +enum b2JointType +{ + e_unknownJoint, + e_revoluteJoint, + e_prismaticJoint, + e_distanceJoint, + e_pulleyJoint, + e_mouseJoint, + e_gearJoint, + e_lineJoint, + e_weldJoint, + e_frictionJoint, +}; + +enum b2LimitState +{ + e_inactiveLimit, + e_atLowerLimit, + e_atUpperLimit, + e_equalLimits +}; + +struct b2Jacobian +{ + b2Vec2 linearA; + float32 angularA; + b2Vec2 linearB; + float32 angularB; + + void SetZero(); + void Set(const b2Vec2& x1, float32 a1, const b2Vec2& x2, float32 a2); + float32 Compute(const b2Vec2& x1, float32 a1, const b2Vec2& x2, float32 a2); +}; + +/// A joint edge is used to connect bodies and joints together +/// in a joint graph where each body is a node and each joint +/// is an edge. A joint edge belongs to a doubly linked list +/// maintained in each attached body. Each joint has two joint +/// nodes, one for each attached body. +struct b2JointEdge +{ + b2Body* other; ///< provides quick access to the other body attached. + b2Joint* joint; ///< the joint + b2JointEdge* prev; ///< the previous joint edge in the body's joint list + b2JointEdge* next; ///< the next joint edge in the body's joint list +}; + +/// Joint definitions are used to construct joints. +struct b2JointDef +{ + b2JointDef() + { + type = e_unknownJoint; + userData = NULL; + bodyA = NULL; + bodyB = NULL; + collideConnected = false; + } + + /// The joint type is set automatically for concrete joint types. + b2JointType type; + + /// Use this to attach application specific data to your joints. + void* userData; + + /// The first attached body. + b2Body* bodyA; + + /// The second attached body. + b2Body* bodyB; + + /// Set this flag to true if the attached bodies should collide. + bool collideConnected; +}; + +/// The base joint class. Joints are used to constraint two bodies together in +/// various fashions. Some joints also feature limits and motors. +class b2Joint +{ +public: + + /// Get the type of the concrete joint. + b2JointType GetType() const; + + /// Get the first body attached to this joint. + b2Body* GetBodyA(); + + /// Get the second body attached to this joint. + b2Body* GetBodyB(); + + /// Get the anchor point on bodyA in world coordinates. + virtual b2Vec2 GetAnchorA() const = 0; + + /// Get the anchor point on bodyB in world coordinates. + virtual b2Vec2 GetAnchorB() const = 0; + + /// Get the reaction force on body2 at the joint anchor in Newtons. + virtual b2Vec2 GetReactionForce(float32 inv_dt) const = 0; + + /// Get the reaction torque on body2 in N*m. + virtual float32 GetReactionTorque(float32 inv_dt) const = 0; + + /// Get the next joint the world joint list. + b2Joint* GetNext(); + + /// Get the user data pointer. + void* GetUserData() const; + + /// Set the user data pointer. + void SetUserData(void* data); + + /// Short-cut function to determine if either body is inactive. + bool IsActive() const; + +protected: + friend class b2World; + friend class b2Body; + friend class b2Island; + + static b2Joint* Create(const b2JointDef* def, b2BlockAllocator* allocator); + static void Destroy(b2Joint* joint, b2BlockAllocator* allocator); + + b2Joint(const b2JointDef* def); + virtual ~b2Joint() {} + + virtual void InitVelocityConstraints(const b2TimeStep& step) = 0; + virtual void SolveVelocityConstraints(const b2TimeStep& step) = 0; + + // This returns true if the position errors are within tolerance. + virtual bool SolvePositionConstraints(float32 baumgarte) = 0; + + b2JointType m_type; + b2Joint* m_prev; + b2Joint* m_next; + b2JointEdge m_edgeA; + b2JointEdge m_edgeB; + b2Body* m_bodyA; + b2Body* m_bodyB; + + bool m_islandFlag; + bool m_collideConnected; + + void* m_userData; + + // Cache here per time step to reduce cache misses. + b2Vec2 m_localCenterA, m_localCenterB; + float32 m_invMassA, m_invIA; + float32 m_invMassB, m_invIB; +}; + +inline void b2Jacobian::SetZero() +{ + linearA.SetZero(); angularA = 0.0f; + linearB.SetZero(); angularB = 0.0f; +} + +inline void b2Jacobian::Set(const b2Vec2& x1, float32 a1, const b2Vec2& x2, float32 a2) +{ + linearA = x1; angularA = a1; + linearB = x2; angularB = a2; +} + +inline float32 b2Jacobian::Compute(const b2Vec2& x1, float32 a1, const b2Vec2& x2, float32 a2) +{ + return b2Dot(linearA, x1) + angularA * a1 + b2Dot(linearB, x2) + angularB * a2; +} + +inline b2JointType b2Joint::GetType() const +{ + return m_type; +} + +inline b2Body* b2Joint::GetBodyA() +{ + return m_bodyA; +} + +inline b2Body* b2Joint::GetBodyB() +{ + return m_bodyB; +} + +inline b2Joint* b2Joint::GetNext() +{ + return m_next; +} + +inline void* b2Joint::GetUserData() const +{ + return m_userData; +} + +inline void b2Joint::SetUserData(void* data) +{ + m_userData = data; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2LineJoint.cpp b/uppsrc/plugin/box2d/b2LineJoint.cpp new file mode 100644 index 000000000..f73506f92 --- /dev/null +++ b/uppsrc/plugin/box2d/b2LineJoint.cpp @@ -0,0 +1,591 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2LineJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// Linear constraint (point-to-line) +// d = p2 - p1 = x2 + r2 - x1 - r1 +// C = dot(perp, d) +// Cdot = dot(d, cross(w1, perp)) + dot(perp, v2 + cross(w2, r2) - v1 - cross(w1, r1)) +// = -dot(perp, v1) - dot(cross(d + r1, perp), w1) + dot(perp, v2) + dot(cross(r2, perp), v2) +// J = [-perp, -cross(d + r1, perp), perp, cross(r2,perp)] +// +// K = J * invM * JT +// +// J = [-a -s1 a s2] +// a = perp +// s1 = cross(d + r1, a) = cross(p2 - x1, a) +// s2 = cross(r2, a) = cross(p2 - x2, a) + + +// Motor/Limit linear constraint +// C = dot(ax1, d) +// Cdot = = -dot(ax1, v1) - dot(cross(d + r1, ax1), w1) + dot(ax1, v2) + dot(cross(r2, ax1), v2) +// J = [-ax1 -cross(d+r1,ax1) ax1 cross(r2,ax1)] + +// Block Solver +// We develop a block solver that includes the joint limit. This makes the limit stiff (inelastic) even +// when the mass has poor distribution (leading to large torques about the joint anchor points). +// +// The Jacobian has 3 rows: +// J = [-uT -s1 uT s2] // linear +// [-vT -a1 vT a2] // limit +// +// u = perp +// v = axis +// s1 = cross(d + r1, u), s2 = cross(r2, u) +// a1 = cross(d + r1, v), a2 = cross(r2, v) + +// M * (v2 - v1) = JT * df +// J * v2 = bias +// +// v2 = v1 + invM * JT * df +// J * (v1 + invM * JT * df) = bias +// K * df = bias - J * v1 = -Cdot +// K = J * invM * JT +// Cdot = J * v1 - bias +// +// Now solve for f2. +// df = f2 - f1 +// K * (f2 - f1) = -Cdot +// f2 = invK * (-Cdot) + f1 +// +// Clamp accumulated limit impulse. +// lower: f2(2) = max(f2(2), 0) +// upper: f2(2) = min(f2(2), 0) +// +// Solve for correct f2(1) +// K(1,1) * f2(1) = -Cdot(1) - K(1,2) * f2(2) + K(1,1:2) * f1 +// = -Cdot(1) - K(1,2) * f2(2) + K(1,1) * f1(1) + K(1,2) * f1(2) +// K(1,1) * f2(1) = -Cdot(1) - K(1,2) * (f2(2) - f1(2)) + K(1,1) * f1(1) +// f2(1) = invK(1,1) * (-Cdot(1) - K(1,2) * (f2(2) - f1(2))) + f1(1) +// +// Now compute impulse to be applied: +// df = f2 - f1 + +void b2LineJointDef::Initialize(b2Body* b1, b2Body* b2, const b2Vec2& anchor, const b2Vec2& axis) +{ + bodyA = b1; + bodyB = b2; + localAnchorA = bodyA->GetLocalPoint(anchor); + localAnchorB = bodyB->GetLocalPoint(anchor); + localAxisA = bodyA->GetLocalVector(axis); +} + +b2LineJoint::b2LineJoint(const b2LineJointDef* def) +: b2Joint(def) +{ + m_localAnchor1 = def->localAnchorA; + m_localAnchor2 = def->localAnchorB; + m_localXAxis1 = def->localAxisA; + m_localYAxis1 = b2Cross(1.0f, m_localXAxis1); + + m_impulse.SetZero(); + m_motorMass = 0.0; + m_motorImpulse = 0.0f; + + m_lowerTranslation = def->lowerTranslation; + m_upperTranslation = def->upperTranslation; + m_maxMotorForce = def->maxMotorForce; + m_motorSpeed = def->motorSpeed; + m_enableLimit = def->enableLimit; + m_enableMotor = def->enableMotor; + m_limitState = e_inactiveLimit; + + m_axis.SetZero(); + m_perp.SetZero(); +} + +void b2LineJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + m_localCenterA = b1->GetLocalCenter(); + m_localCenterB = b2->GetLocalCenter(); + + b2Transform xf1 = b1->GetTransform(); + b2Transform xf2 = b2->GetTransform(); + + // Compute the effective masses. + b2Vec2 r1 = b2Mul(xf1.R, m_localAnchor1 - m_localCenterA); + b2Vec2 r2 = b2Mul(xf2.R, m_localAnchor2 - m_localCenterB); + b2Vec2 d = b2->m_sweep.c + r2 - b1->m_sweep.c - r1; + + m_invMassA = b1->m_invMass; + m_invIA = b1->m_invI; + m_invMassB = b2->m_invMass; + m_invIB = b2->m_invI; + + // Compute motor Jacobian and effective mass. + { + m_axis = b2Mul(xf1.R, m_localXAxis1); + m_a1 = b2Cross(d + r1, m_axis); + m_a2 = b2Cross(r2, m_axis); + + m_motorMass = m_invMassA + m_invMassB + m_invIA * m_a1 * m_a1 + m_invIB * m_a2 * m_a2; + if (m_motorMass > b2_epsilon) + { + m_motorMass = 1.0f / m_motorMass; + } + else + { + m_motorMass = 0.0f; + } + } + + // Prismatic constraint. + { + m_perp = b2Mul(xf1.R, m_localYAxis1); + + m_s1 = b2Cross(d + r1, m_perp); + m_s2 = b2Cross(r2, m_perp); + + float32 m1 = m_invMassA, m2 = m_invMassB; + float32 i1 = m_invIA, i2 = m_invIB; + + float32 k11 = m1 + m2 + i1 * m_s1 * m_s1 + i2 * m_s2 * m_s2; + float32 k12 = i1 * m_s1 * m_a1 + i2 * m_s2 * m_a2; + float32 k22 = m1 + m2 + i1 * m_a1 * m_a1 + i2 * m_a2 * m_a2; + + m_K.col1.Set(k11, k12); + m_K.col2.Set(k12, k22); + } + + // Compute motor and limit terms. + if (m_enableLimit) + { + float32 jointTranslation = b2Dot(m_axis, d); + if (b2Abs(m_upperTranslation - m_lowerTranslation) < 2.0f * b2_linearSlop) + { + m_limitState = e_equalLimits; + } + else if (jointTranslation <= m_lowerTranslation) + { + if (m_limitState != e_atLowerLimit) + { + m_limitState = e_atLowerLimit; + m_impulse.y = 0.0f; + } + } + else if (jointTranslation >= m_upperTranslation) + { + if (m_limitState != e_atUpperLimit) + { + m_limitState = e_atUpperLimit; + m_impulse.y = 0.0f; + } + } + else + { + m_limitState = e_inactiveLimit; + m_impulse.y = 0.0f; + } + } + else + { + m_limitState = e_inactiveLimit; + } + + if (m_enableMotor == false) + { + m_motorImpulse = 0.0f; + } + + if (step.warmStarting) + { + // Account for variable time step. + m_impulse *= step.dtRatio; + m_motorImpulse *= step.dtRatio; + + b2Vec2 P = m_impulse.x * m_perp + (m_motorImpulse + m_impulse.y) * m_axis; + float32 L1 = m_impulse.x * m_s1 + (m_motorImpulse + m_impulse.y) * m_a1; + float32 L2 = m_impulse.x * m_s2 + (m_motorImpulse + m_impulse.y) * m_a2; + + b1->m_linearVelocity -= m_invMassA * P; + b1->m_angularVelocity -= m_invIA * L1; + + b2->m_linearVelocity += m_invMassB * P; + b2->m_angularVelocity += m_invIB * L2; + } + else + { + m_impulse.SetZero(); + m_motorImpulse = 0.0f; + } +} + +void b2LineJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 v1 = b1->m_linearVelocity; + float32 w1 = b1->m_angularVelocity; + b2Vec2 v2 = b2->m_linearVelocity; + float32 w2 = b2->m_angularVelocity; + + // Solve linear motor constraint. + if (m_enableMotor && m_limitState != e_equalLimits) + { + float32 Cdot = b2Dot(m_axis, v2 - v1) + m_a2 * w2 - m_a1 * w1; + float32 impulse = m_motorMass * (m_motorSpeed - Cdot); + float32 oldImpulse = m_motorImpulse; + float32 maxImpulse = step.dt * m_maxMotorForce; + m_motorImpulse = b2Clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse); + impulse = m_motorImpulse - oldImpulse; + + b2Vec2 P = impulse * m_axis; + float32 L1 = impulse * m_a1; + float32 L2 = impulse * m_a2; + + v1 -= m_invMassA * P; + w1 -= m_invIA * L1; + + v2 += m_invMassB * P; + w2 += m_invIB * L2; + } + + float32 Cdot1 = b2Dot(m_perp, v2 - v1) + m_s2 * w2 - m_s1 * w1; + + if (m_enableLimit && m_limitState != e_inactiveLimit) + { + // Solve prismatic and limit constraint in block form. + float32 Cdot2 = b2Dot(m_axis, v2 - v1) + m_a2 * w2 - m_a1 * w1; + b2Vec2 Cdot(Cdot1, Cdot2); + + b2Vec2 f1 = m_impulse; + b2Vec2 df = m_K.Solve(-Cdot); + m_impulse += df; + + if (m_limitState == e_atLowerLimit) + { + m_impulse.y = b2Max(m_impulse.y, 0.0f); + } + else if (m_limitState == e_atUpperLimit) + { + m_impulse.y = b2Min(m_impulse.y, 0.0f); + } + + // f2(1) = invK(1,1) * (-Cdot(1) - K(1,2) * (f2(2) - f1(2))) + f1(1) + float32 b = -Cdot1 - (m_impulse.y - f1.y) * m_K.col2.x; + float32 f2r; + if (m_K.col1.x != 0.0f) + { + f2r = b / m_K.col1.x + f1.x; + } + else + { + f2r = f1.x; + } + + m_impulse.x = f2r; + + df = m_impulse - f1; + + b2Vec2 P = df.x * m_perp + df.y * m_axis; + float32 L1 = df.x * m_s1 + df.y * m_a1; + float32 L2 = df.x * m_s2 + df.y * m_a2; + + v1 -= m_invMassA * P; + w1 -= m_invIA * L1; + + v2 += m_invMassB * P; + w2 += m_invIB * L2; + } + else + { + // Limit is inactive, just solve the prismatic constraint in block form. + float32 df; + if (m_K.col1.x != 0.0f) + { + df = - Cdot1 / m_K.col1.x; + } + else + { + df = 0.0f; + } + m_impulse.x += df; + + b2Vec2 P = df * m_perp; + float32 L1 = df * m_s1; + float32 L2 = df * m_s2; + + v1 -= m_invMassA * P; + w1 -= m_invIA * L1; + + v2 += m_invMassB * P; + w2 += m_invIB * L2; + } + + b1->m_linearVelocity = v1; + b1->m_angularVelocity = w1; + b2->m_linearVelocity = v2; + b2->m_angularVelocity = w2; +} + +bool b2LineJoint::SolvePositionConstraints(float32 baumgarte) +{ + B2_NOT_USED(baumgarte); + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 c1 = b1->m_sweep.c; + float32 a1 = b1->m_sweep.a; + + b2Vec2 c2 = b2->m_sweep.c; + float32 a2 = b2->m_sweep.a; + + // Solve linear limit constraint. + float32 linearError = 0.0f, angularError = 0.0f; + bool active = false; + float32 C2 = 0.0f; + + b2Mat22 R1(a1), R2(a2); + + b2Vec2 r1 = b2Mul(R1, m_localAnchor1 - m_localCenterA); + b2Vec2 r2 = b2Mul(R2, m_localAnchor2 - m_localCenterB); + b2Vec2 d = c2 + r2 - c1 - r1; + + if (m_enableLimit) + { + m_axis = b2Mul(R1, m_localXAxis1); + + m_a1 = b2Cross(d + r1, m_axis); + m_a2 = b2Cross(r2, m_axis); + + float32 translation = b2Dot(m_axis, d); + if (b2Abs(m_upperTranslation - m_lowerTranslation) < 2.0f * b2_linearSlop) + { + // Prevent large angular corrections + C2 = b2Clamp(translation, -b2_maxLinearCorrection, b2_maxLinearCorrection); + linearError = b2Abs(translation); + active = true; + } + else if (translation <= m_lowerTranslation) + { + // Prevent large linear corrections and allow some slop. + C2 = b2Clamp(translation - m_lowerTranslation + b2_linearSlop, -b2_maxLinearCorrection, 0.0f); + linearError = m_lowerTranslation - translation; + active = true; + } + else if (translation >= m_upperTranslation) + { + // Prevent large linear corrections and allow some slop. + C2 = b2Clamp(translation - m_upperTranslation - b2_linearSlop, 0.0f, b2_maxLinearCorrection); + linearError = translation - m_upperTranslation; + active = true; + } + } + + m_perp = b2Mul(R1, m_localYAxis1); + + m_s1 = b2Cross(d + r1, m_perp); + m_s2 = b2Cross(r2, m_perp); + + b2Vec2 impulse; + float32 C1; + C1 = b2Dot(m_perp, d); + + linearError = b2Max(linearError, b2Abs(C1)); + angularError = 0.0f; + + if (active) + { + float32 m1 = m_invMassA, m2 = m_invMassB; + float32 i1 = m_invIA, i2 = m_invIB; + + float32 k11 = m1 + m2 + i1 * m_s1 * m_s1 + i2 * m_s2 * m_s2; + float32 k12 = i1 * m_s1 * m_a1 + i2 * m_s2 * m_a2; + float32 k22 = m1 + m2 + i1 * m_a1 * m_a1 + i2 * m_a2 * m_a2; + + m_K.col1.Set(k11, k12); + m_K.col2.Set(k12, k22); + + b2Vec2 C; + C.x = C1; + C.y = C2; + + impulse = m_K.Solve(-C); + } + else + { + float32 m1 = m_invMassA, m2 = m_invMassB; + float32 i1 = m_invIA, i2 = m_invIB; + + float32 k11 = m1 + m2 + i1 * m_s1 * m_s1 + i2 * m_s2 * m_s2; + + float32 impulse1; + if (k11 != 0.0f) + { + impulse1 = - C1 / k11; + } + else + { + impulse1 = 0.0f; + } + + impulse.x = impulse1; + impulse.y = 0.0f; + } + + b2Vec2 P = impulse.x * m_perp + impulse.y * m_axis; + float32 L1 = impulse.x * m_s1 + impulse.y * m_a1; + float32 L2 = impulse.x * m_s2 + impulse.y * m_a2; + + c1 -= m_invMassA * P; + a1 -= m_invIA * L1; + c2 += m_invMassB * P; + a2 += m_invIB * L2; + + // TODO_ERIN remove need for this. + b1->m_sweep.c = c1; + b1->m_sweep.a = a1; + b2->m_sweep.c = c2; + b2->m_sweep.a = a2; + b1->SynchronizeTransform(); + b2->SynchronizeTransform(); + + return linearError <= b2_linearSlop && angularError <= b2_angularSlop; +} + +b2Vec2 b2LineJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchor1); +} + +b2Vec2 b2LineJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchor2); +} + +b2Vec2 b2LineJoint::GetReactionForce(float32 inv_dt) const +{ + return inv_dt * (m_impulse.x * m_perp + (m_motorImpulse + m_impulse.y) * m_axis); +} + +float32 b2LineJoint::GetReactionTorque(float32 inv_dt) const +{ + B2_NOT_USED(inv_dt); + return 0.0f; +} + +float32 b2LineJoint::GetJointTranslation() const +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 p1 = b1->GetWorldPoint(m_localAnchor1); + b2Vec2 p2 = b2->GetWorldPoint(m_localAnchor2); + b2Vec2 d = p2 - p1; + b2Vec2 axis = b1->GetWorldVector(m_localXAxis1); + + float32 translation = b2Dot(d, axis); + return translation; +} + +float32 b2LineJoint::GetJointSpeed() const +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + b2Vec2 p1 = b1->m_sweep.c + r1; + b2Vec2 p2 = b2->m_sweep.c + r2; + b2Vec2 d = p2 - p1; + b2Vec2 axis = b1->GetWorldVector(m_localXAxis1); + + b2Vec2 v1 = b1->m_linearVelocity; + b2Vec2 v2 = b2->m_linearVelocity; + float32 w1 = b1->m_angularVelocity; + float32 w2 = b2->m_angularVelocity; + + float32 speed = b2Dot(d, b2Cross(w1, axis)) + b2Dot(axis, v2 + b2Cross(w2, r2) - v1 - b2Cross(w1, r1)); + return speed; +} + +bool b2LineJoint::IsLimitEnabled() const +{ + return m_enableLimit; +} + +void b2LineJoint::EnableLimit(bool flag) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableLimit = flag; +} + +float32 b2LineJoint::GetLowerLimit() const +{ + return m_lowerTranslation; +} + +float32 b2LineJoint::GetUpperLimit() const +{ + return m_upperTranslation; +} + +void b2LineJoint::SetLimits(float32 lower, float32 upper) +{ + b2Assert(lower <= upper); + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_lowerTranslation = lower; + m_upperTranslation = upper; +} + +bool b2LineJoint::IsMotorEnabled() const +{ + return m_enableMotor; +} + +void b2LineJoint::EnableMotor(bool flag) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableMotor = flag; +} + +void b2LineJoint::SetMotorSpeed(float32 speed) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_motorSpeed = speed; +} + +void b2LineJoint::SetMaxMotorForce(float32 force) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_maxMotorForce = force; +} + +float32 b2LineJoint::GetMotorForce() const +{ + return m_motorImpulse; +} + + + + + diff --git a/uppsrc/plugin/box2d/b2LineJoint.h b/uppsrc/plugin/box2d/b2LineJoint.h new file mode 100644 index 000000000..f3f1510f4 --- /dev/null +++ b/uppsrc/plugin/box2d/b2LineJoint.h @@ -0,0 +1,170 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_LINE_JOINT_H +#define B2_LINE_JOINT_H + +#include "b2Joint.h" + +/// Line joint definition. This requires defining a line of +/// motion using an axis and an anchor point. The definition uses local +/// anchor points and a local axis so that the initial configuration +/// can violate the constraint slightly. The joint translation is zero +/// when the local anchor points coincide in world space. Using local +/// anchors and a local axis helps when saving and loading a game. +struct b2LineJointDef : public b2JointDef +{ + b2LineJointDef() + { + type = e_lineJoint; + localAnchorA.SetZero(); + localAnchorB.SetZero(); + localAxisA.Set(1.0f, 0.0f); + enableLimit = false; + lowerTranslation = 0.0f; + upperTranslation = 0.0f; + enableMotor = false; + maxMotorForce = 0.0f; + motorSpeed = 0.0f; + } + + /// Initialize the bodies, anchors, axis, and reference angle using the world + /// anchor and world axis. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor, const b2Vec2& axis); + + /// The local anchor point relative to body1's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to body2's origin. + b2Vec2 localAnchorB; + + /// The local translation axis in body1. + b2Vec2 localAxisA; + + /// Enable/disable the joint limit. + bool enableLimit; + + /// The lower translation limit, usually in meters. + float32 lowerTranslation; + + /// The upper translation limit, usually in meters. + float32 upperTranslation; + + /// Enable/disable the joint motor. + bool enableMotor; + + /// The maximum motor torque, usually in N-m. + float32 maxMotorForce; + + /// The desired motor speed in radians per second. + float32 motorSpeed; +}; + +/// A line joint. This joint provides two degrees of freedom: translation +/// along an axis fixed in body1 and rotation in the plane. You can use a +/// joint limit to restrict the range of motion and a joint motor to drive +/// the motion or to model joint friction. +class b2LineJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const; + b2Vec2 GetAnchorB() const; + + b2Vec2 GetReactionForce(float32 inv_dt) const; + float32 GetReactionTorque(float32 inv_dt) const; + + /// Get the current joint translation, usually in meters. + float32 GetJointTranslation() const; + + /// Get the current joint translation speed, usually in meters per second. + float32 GetJointSpeed() const; + + /// Is the joint limit enabled? + bool IsLimitEnabled() const; + + /// Enable/disable the joint limit. + void EnableLimit(bool flag); + + /// Get the lower joint limit, usually in meters. + float32 GetLowerLimit() const; + + /// Get the upper joint limit, usually in meters. + float32 GetUpperLimit() const; + + /// Set the joint limits, usually in meters. + void SetLimits(float32 lower, float32 upper); + + /// Is the joint motor enabled? + bool IsMotorEnabled() const; + + /// Enable/disable the joint motor. + void EnableMotor(bool flag); + + /// Set the motor speed, usually in meters per second. + void SetMotorSpeed(float32 speed); + + /// Get the motor speed, usually in meters per second. + float32 GetMotorSpeed() const; + + /// Set/Get the maximum motor force, usually in N. + void SetMaxMotorForce(float32 force); + float32 GetMaxMotorForce() const; + + /// Get the current motor force, usually in N. + float32 GetMotorForce() const; + +protected: + + friend class b2Joint; + b2LineJoint(const b2LineJointDef* def); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + bool SolvePositionConstraints(float32 baumgarte); + + b2Vec2 m_localAnchor1; + b2Vec2 m_localAnchor2; + b2Vec2 m_localXAxis1; + b2Vec2 m_localYAxis1; + + b2Vec2 m_axis, m_perp; + float32 m_s1, m_s2; + float32 m_a1, m_a2; + + b2Mat22 m_K; + b2Vec2 m_impulse; + + float32 m_motorMass; // effective mass for motor/limit translational constraint. + float32 m_motorImpulse; + + float32 m_lowerTranslation; + float32 m_upperTranslation; + float32 m_maxMotorForce; + float32 m_motorSpeed; + + bool m_enableLimit; + bool m_enableMotor; + b2LimitState m_limitState; +}; + +inline float32 b2LineJoint::GetMotorSpeed() const +{ + return m_motorSpeed; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2Math.cpp b/uppsrc/plugin/box2d/b2Math.cpp new file mode 100644 index 000000000..95d76c416 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Math.cpp @@ -0,0 +1,55 @@ +/* +* Copyright (c) 2007-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Math.h" + +const b2Vec2 b2Vec2_zero(0.0f, 0.0f); +const b2Mat22 b2Mat22_identity(1.0f, 0.0f, 0.0f, 1.0f); +const b2Transform b2Transform_identity(b2Vec2_zero, b2Mat22_identity); + +/// Solve A * x = b, where b is a column vector. This is more efficient +/// than computing the inverse in one-shot cases. +b2Vec3 b2Mat33::Solve33(const b2Vec3& b) const +{ + float32 det = b2Dot(col1, b2Cross(col2, col3)); + if (det != 0.0f) + { + det = 1.0f / det; + } + b2Vec3 x; + x.x = det * b2Dot(b, b2Cross(col2, col3)); + x.y = det * b2Dot(col1, b2Cross(b, col3)); + x.z = det * b2Dot(col1, b2Cross(col2, b)); + return x; +} + +/// Solve A * x = b, where b is a column vector. This is more efficient +/// than computing the inverse in one-shot cases. +b2Vec2 b2Mat33::Solve22(const b2Vec2& b) const +{ + float32 a11 = col1.x, a12 = col2.x, a21 = col1.y, a22 = col2.y; + float32 det = a11 * a22 - a12 * a21; + if (det != 0.0f) + { + det = 1.0f / det; + } + b2Vec2 x; + x.x = det * (a22 * b.x - a12 * b.y); + x.y = det * (a11 * b.y - a21 * b.x); + return x; +} diff --git a/uppsrc/plugin/box2d/b2Math.h b/uppsrc/plugin/box2d/b2Math.h new file mode 100644 index 000000000..cfc0673b1 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Math.h @@ -0,0 +1,624 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_MATH_H +#define B2_MATH_H + +#include "b2Settings.h" + +#include +#include +#include +#include + +/// This function is used to ensure that a floating point number is +/// not a NaN or infinity. +inline bool b2IsValid(float32 x) +{ + if (x != x) + { + // NaN. + return false; + } + + float32 infinity = std::numeric_limits::infinity(); + return -infinity < x && x < infinity; +} + +/// This is a approximate yet fast inverse square-root. +inline float32 b2InvSqrt(float32 x) +{ + union + { + float32 x; + int32 i; + } convert; + + convert.x = x; + float32 xhalf = 0.5f * x; + convert.i = 0x5f3759df - (convert.i >> 1); + x = convert.x; + x = x * (1.5f - xhalf * x * x); + return x; +} + +#define b2Sqrt(x) sqrtf(x) +#define b2Atan2(y, x) atan2f(y, x) + +inline float32 b2Abs(float32 a) +{ + return a > 0.0f ? a : -a; +} + +/// A 2D column vector. +struct b2Vec2 +{ + /// Default constructor does nothing (for performance). + b2Vec2() {} + + /// Construct using coordinates. + b2Vec2(float32 x, float32 y) : x(x), y(y) {} + + /// Set this vector to all zeros. + void SetZero() { x = 0.0f; y = 0.0f; } + + /// Set this vector to some specified coordinates. + void Set(float32 x_, float32 y_) { x = x_; y = y_; } + + /// Negate this vector. + b2Vec2 operator -() const { b2Vec2 v; v.Set(-x, -y); return v; } + + /// Read from and indexed element. + float32 operator () (int32 i) const + { + return (&x)[i]; + } + + /// Write to an indexed element. + float32& operator () (int32 i) + { + return (&x)[i]; + } + + /// Add a vector to this vector. + void operator += (const b2Vec2& v) + { + x += v.x; y += v.y; + } + + /// Subtract a vector from this vector. + void operator -= (const b2Vec2& v) + { + x -= v.x; y -= v.y; + } + + /// Multiply this vector by a scalar. + void operator *= (float32 a) + { + x *= a; y *= a; + } + + /// Get the length of this vector (the norm). + float32 Length() const + { + return b2Sqrt(x * x + y * y); + } + + /// Get the length squared. For performance, use this instead of + /// b2Vec2::Length (if possible). + float32 LengthSquared() const + { + return x * x + y * y; + } + + /// Convert this vector into a unit vector. Returns the length. + float32 Normalize() + { + float32 length = Length(); + if (length < b2_epsilon) + { + return 0.0f; + } + float32 invLength = 1.0f / length; + x *= invLength; + y *= invLength; + + return length; + } + + /// Does this vector contain finite coordinates? + bool IsValid() const + { + return b2IsValid(x) && b2IsValid(y); + } + + float32 x, y; +}; + +/// A 2D column vector with 3 elements. +struct b2Vec3 +{ + /// Default constructor does nothing (for performance). + b2Vec3() {} + + /// Construct using coordinates. + b2Vec3(float32 x, float32 y, float32 z) : x(x), y(y), z(z) {} + + /// Set this vector to all zeros. + void SetZero() { x = 0.0f; y = 0.0f; z = 0.0f; } + + /// Set this vector to some specified coordinates. + void Set(float32 x_, float32 y_, float32 z_) { x = x_; y = y_; z = z_; } + + /// Negate this vector. + b2Vec3 operator -() const { b2Vec3 v; v.Set(-x, -y, -z); return v; } + + /// Add a vector to this vector. + void operator += (const b2Vec3& v) + { + x += v.x; y += v.y; z += v.z; + } + + /// Subtract a vector from this vector. + void operator -= (const b2Vec3& v) + { + x -= v.x; y -= v.y; z -= v.z; + } + + /// Multiply this vector by a scalar. + void operator *= (float32 s) + { + x *= s; y *= s; z *= s; + } + + float32 x, y, z; +}; + +/// A 2-by-2 matrix. Stored in column-major order. +struct b2Mat22 +{ + /// The default constructor does nothing (for performance). + b2Mat22() {} + + /// Construct this matrix using columns. + b2Mat22(const b2Vec2& c1, const b2Vec2& c2) + { + col1 = c1; + col2 = c2; + } + + /// Construct this matrix using scalars. + b2Mat22(float32 a11, float32 a12, float32 a21, float32 a22) + { + col1.x = a11; col1.y = a21; + col2.x = a12; col2.y = a22; + } + + /// Construct this matrix using an angle. This matrix becomes + /// an orthonormal rotation matrix. + explicit b2Mat22(float32 angle) + { + // TODO_ERIN compute sin+cos together. + float32 c = cosf(angle), s = sinf(angle); + col1.x = c; col2.x = -s; + col1.y = s; col2.y = c; + } + + /// Initialize this matrix using columns. + void Set(const b2Vec2& c1, const b2Vec2& c2) + { + col1 = c1; + col2 = c2; + } + + /// Initialize this matrix using an angle. This matrix becomes + /// an orthonormal rotation matrix. + void Set(float32 angle) + { + float32 c = cosf(angle), s = sinf(angle); + col1.x = c; col2.x = -s; + col1.y = s; col2.y = c; + } + + /// Set this to the identity matrix. + void SetIdentity() + { + col1.x = 1.0f; col2.x = 0.0f; + col1.y = 0.0f; col2.y = 1.0f; + } + + /// Set this matrix to all zeros. + void SetZero() + { + col1.x = 0.0f; col2.x = 0.0f; + col1.y = 0.0f; col2.y = 0.0f; + } + + /// Extract the angle from this matrix (assumed to be + /// a rotation matrix). + float32 GetAngle() const + { + return b2Atan2(col1.y, col1.x); + } + + b2Mat22 GetInverse() const + { + float32 a = col1.x, b = col2.x, c = col1.y, d = col2.y; + b2Mat22 B; + float32 det = a * d - b * c; + if (det != 0.0f) + { + det = 1.0f / det; + } + B.col1.x = det * d; B.col2.x = -det * b; + B.col1.y = -det * c; B.col2.y = det * a; + return B; + } + + /// Solve A * x = b, where b is a column vector. This is more efficient + /// than computing the inverse in one-shot cases. + b2Vec2 Solve(const b2Vec2& b) const + { + float32 a11 = col1.x, a12 = col2.x, a21 = col1.y, a22 = col2.y; + float32 det = a11 * a22 - a12 * a21; + if (det != 0.0f) + { + det = 1.0f / det; + } + b2Vec2 x; + x.x = det * (a22 * b.x - a12 * b.y); + x.y = det * (a11 * b.y - a21 * b.x); + return x; + } + + b2Vec2 col1, col2; +}; + +/// A 3-by-3 matrix. Stored in column-major order. +struct b2Mat33 +{ + /// The default constructor does nothing (for performance). + b2Mat33() {} + + /// Construct this matrix using columns. + b2Mat33(const b2Vec3& c1, const b2Vec3& c2, const b2Vec3& c3) + { + col1 = c1; + col2 = c2; + col3 = c3; + } + + /// Set this matrix to all zeros. + void SetZero() + { + col1.SetZero(); + col2.SetZero(); + col3.SetZero(); + } + + /// Solve A * x = b, where b is a column vector. This is more efficient + /// than computing the inverse in one-shot cases. + b2Vec3 Solve33(const b2Vec3& b) const; + + /// Solve A * x = b, where b is a column vector. This is more efficient + /// than computing the inverse in one-shot cases. Solve only the upper + /// 2-by-2 matrix equation. + b2Vec2 Solve22(const b2Vec2& b) const; + + b2Vec3 col1, col2, col3; +}; + +/// A transform contains translation and rotation. It is used to represent +/// the position and orientation of rigid frames. +struct b2Transform +{ + /// The default constructor does nothing (for performance). + b2Transform() {} + + /// Initialize using a position vector and a rotation matrix. + b2Transform(const b2Vec2& position, const b2Mat22& R) : position(position), R(R) {} + + /// Set this to the identity transform. + void SetIdentity() + { + position.SetZero(); + R.SetIdentity(); + } + + /// Set this based on the position and angle. + void Set(const b2Vec2& p, float32 angle) + { + position = p; + R.Set(angle); + } + + /// Calculate the angle that the rotation matrix represents. + float32 GetAngle() const + { + return b2Atan2(R.col1.y, R.col1.x); + } + + b2Vec2 position; + b2Mat22 R; +}; + +/// This describes the motion of a body/shape for TOI computation. +/// Shapes are defined with respect to the body origin, which may +/// no coincide with the center of mass. However, to support dynamics +/// we must interpolate the center of mass position. +struct b2Sweep +{ + /// Get the interpolated transform at a specific time. + /// @param alpha is a factor in [0,1], where 0 indicates t0. + void GetTransform(b2Transform* xf, float32 alpha) const; + + /// Advance the sweep forward, yielding a new initial state. + /// @param t the new initial time. + void Advance(float32 t); + + /// Normalize the angles. + void Normalize(); + + b2Vec2 localCenter; ///< local center of mass position + b2Vec2 c0, c; ///< center world positions + float32 a0, a; ///< world angles +}; + + +extern const b2Vec2 b2Vec2_zero; +extern const b2Mat22 b2Mat22_identity; +extern const b2Transform b2Transform_identity; + +/// Perform the dot product on two vectors. +inline float32 b2Dot(const b2Vec2& a, const b2Vec2& b) +{ + return a.x * b.x + a.y * b.y; +} + +/// Perform the cross product on two vectors. In 2D this produces a scalar. +inline float32 b2Cross(const b2Vec2& a, const b2Vec2& b) +{ + return a.x * b.y - a.y * b.x; +} + +/// Perform the cross product on a vector and a scalar. In 2D this produces +/// a vector. +inline b2Vec2 b2Cross(const b2Vec2& a, float32 s) +{ + return b2Vec2(s * a.y, -s * a.x); +} + +/// Perform the cross product on a scalar and a vector. In 2D this produces +/// a vector. +inline b2Vec2 b2Cross(float32 s, const b2Vec2& a) +{ + return b2Vec2(-s * a.y, s * a.x); +} + +/// Multiply a matrix times a vector. If a rotation matrix is provided, +/// then this transforms the vector from one frame to another. +inline b2Vec2 b2Mul(const b2Mat22& A, const b2Vec2& v) +{ + return b2Vec2(A.col1.x * v.x + A.col2.x * v.y, A.col1.y * v.x + A.col2.y * v.y); +} + +/// Multiply a matrix transpose times a vector. If a rotation matrix is provided, +/// then this transforms the vector from one frame to another (inverse transform). +inline b2Vec2 b2MulT(const b2Mat22& A, const b2Vec2& v) +{ + return b2Vec2(b2Dot(v, A.col1), b2Dot(v, A.col2)); +} + +/// Add two vectors component-wise. +inline b2Vec2 operator + (const b2Vec2& a, const b2Vec2& b) +{ + return b2Vec2(a.x + b.x, a.y + b.y); +} + +/// Subtract two vectors component-wise. +inline b2Vec2 operator - (const b2Vec2& a, const b2Vec2& b) +{ + return b2Vec2(a.x - b.x, a.y - b.y); +} + +inline b2Vec2 operator * (float32 s, const b2Vec2& a) +{ + return b2Vec2(s * a.x, s * a.y); +} + +inline bool operator == (const b2Vec2& a, const b2Vec2& b) +{ + return a.x == b.x && a.y == b.y; +} + +inline float32 b2Distance(const b2Vec2& a, const b2Vec2& b) +{ + b2Vec2 c = a - b; + return c.Length(); +} + +inline float32 b2DistanceSquared(const b2Vec2& a, const b2Vec2& b) +{ + b2Vec2 c = a - b; + return b2Dot(c, c); +} + +inline b2Vec3 operator * (float32 s, const b2Vec3& a) +{ + return b2Vec3(s * a.x, s * a.y, s * a.z); +} + +/// Add two vectors component-wise. +inline b2Vec3 operator + (const b2Vec3& a, const b2Vec3& b) +{ + return b2Vec3(a.x + b.x, a.y + b.y, a.z + b.z); +} + +/// Subtract two vectors component-wise. +inline b2Vec3 operator - (const b2Vec3& a, const b2Vec3& b) +{ + return b2Vec3(a.x - b.x, a.y - b.y, a.z - b.z); +} + +/// Perform the dot product on two vectors. +inline float32 b2Dot(const b2Vec3& a, const b2Vec3& b) +{ + return a.x * b.x + a.y * b.y + a.z * b.z; +} + +/// Perform the cross product on two vectors. +inline b2Vec3 b2Cross(const b2Vec3& a, const b2Vec3& b) +{ + return b2Vec3(a.y * b.z - a.z * b.y, a.z * b.x - a.x * b.z, a.x * b.y - a.y * b.x); +} + +inline b2Mat22 operator + (const b2Mat22& A, const b2Mat22& B) +{ + return b2Mat22(A.col1 + B.col1, A.col2 + B.col2); +} + +// A * B +inline b2Mat22 b2Mul(const b2Mat22& A, const b2Mat22& B) +{ + return b2Mat22(b2Mul(A, B.col1), b2Mul(A, B.col2)); +} + +// A^T * B +inline b2Mat22 b2MulT(const b2Mat22& A, const b2Mat22& B) +{ + b2Vec2 c1(b2Dot(A.col1, B.col1), b2Dot(A.col2, B.col1)); + b2Vec2 c2(b2Dot(A.col1, B.col2), b2Dot(A.col2, B.col2)); + return b2Mat22(c1, c2); +} + +/// Multiply a matrix times a vector. +inline b2Vec3 b2Mul(const b2Mat33& A, const b2Vec3& v) +{ + return v.x * A.col1 + v.y * A.col2 + v.z * A.col3; +} + +inline b2Vec2 b2Mul(const b2Transform& T, const b2Vec2& v) +{ + float32 x = T.position.x + T.R.col1.x * v.x + T.R.col2.x * v.y; + float32 y = T.position.y + T.R.col1.y * v.x + T.R.col2.y * v.y; + + return b2Vec2(x, y); +} + +inline b2Vec2 b2MulT(const b2Transform& T, const b2Vec2& v) +{ + return b2MulT(T.R, v - T.position); +} + +inline b2Vec2 b2Abs(const b2Vec2& a) +{ + return b2Vec2(b2Abs(a.x), b2Abs(a.y)); +} + +inline b2Mat22 b2Abs(const b2Mat22& A) +{ + return b2Mat22(b2Abs(A.col1), b2Abs(A.col2)); +} + +template +inline T b2Min(T a, T b) +{ + return a < b ? a : b; +} + +inline b2Vec2 b2Min(const b2Vec2& a, const b2Vec2& b) +{ + return b2Vec2(b2Min(a.x, b.x), b2Min(a.y, b.y)); +} + +template +inline T b2Max(T a, T b) +{ + return a > b ? a : b; +} + +inline b2Vec2 b2Max(const b2Vec2& a, const b2Vec2& b) +{ + return b2Vec2(b2Max(a.x, b.x), b2Max(a.y, b.y)); +} + +template +inline T b2Clamp(T a, T low, T high) +{ + return b2Max(low, b2Min(a, high)); +} + +inline b2Vec2 b2Clamp(const b2Vec2& a, const b2Vec2& low, const b2Vec2& high) +{ + return b2Max(low, b2Min(a, high)); +} + +template inline void b2Swap(T& a, T& b) +{ + T tmp = a; + a = b; + b = tmp; +} + +/// "Next Largest Power of 2 +/// Given a binary integer value x, the next largest power of 2 can be computed by a SWAR algorithm +/// that recursively "folds" the upper bits into the lower bits. This process yields a bit vector with +/// the same most significant 1 as x, but all 1's below it. Adding 1 to that value yields the next +/// largest power of 2. For a 32-bit value:" +inline uint32 b2NextPowerOfTwo(uint32 x) +{ + x |= (x >> 1); + x |= (x >> 2); + x |= (x >> 4); + x |= (x >> 8); + x |= (x >> 16); + return x + 1; +} + +inline bool b2IsPowerOfTwo(uint32 x) +{ + bool result = x > 0 && (x & (x - 1)) == 0; + return result; +} + +inline void b2Sweep::GetTransform(b2Transform* xf, float32 alpha) const +{ + xf->position = (1.0f - alpha) * c0 + alpha * c; + float32 angle = (1.0f - alpha) * a0 + alpha * a; + xf->R.Set(angle); + + // Shift to origin + xf->position -= b2Mul(xf->R, localCenter); +} + +inline void b2Sweep::Advance(float32 t) +{ + c0 = (1.0f - t) * c0 + t * c; + a0 = (1.0f - t) * a0 + t * a; +} + +/// Normalize an angle in radians to be between -pi and pi +inline void b2Sweep::Normalize() +{ + float32 twoPi = 2.0f * b2_pi; + float32 d = twoPi * floorf(a0 / twoPi); + a0 -= d; + a -= d; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2MouseJoint.cpp b/uppsrc/plugin/box2d/b2MouseJoint.cpp new file mode 100644 index 000000000..12c0fba1c --- /dev/null +++ b/uppsrc/plugin/box2d/b2MouseJoint.cpp @@ -0,0 +1,197 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2MouseJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// p = attached point, m = mouse point +// C = p - m +// Cdot = v +// = v + cross(w, r) +// J = [I r_skew] +// Identity used: +// w k % (rx i + ry j) = w * (-ry i + rx j) + +b2MouseJoint::b2MouseJoint(const b2MouseJointDef* def) +: b2Joint(def) +{ + b2Assert(def->target.IsValid()); + b2Assert(b2IsValid(def->maxForce) && def->maxForce >= 0.0f); + b2Assert(b2IsValid(def->frequencyHz) && def->frequencyHz >= 0.0f); + b2Assert(b2IsValid(def->dampingRatio) && def->dampingRatio >= 0.0f); + + m_target = def->target; + m_localAnchor = b2MulT(m_bodyB->GetTransform(), m_target); + + m_maxForce = def->maxForce; + m_impulse.SetZero(); + + m_frequencyHz = def->frequencyHz; + m_dampingRatio = def->dampingRatio; + + m_beta = 0.0f; + m_gamma = 0.0f; +} + +void b2MouseJoint::SetTarget(const b2Vec2& target) +{ + if (m_bodyB->IsAwake() == false) + { + m_bodyB->SetAwake(true); + } + m_target = target; +} + +const b2Vec2& b2MouseJoint::GetTarget() const +{ + return m_target; +} + +void b2MouseJoint::SetMaxForce(float32 force) +{ + m_maxForce = force; +} + +float32 b2MouseJoint::GetMaxForce() const +{ + return m_maxForce; +} + +void b2MouseJoint::SetFrequency(float32 hz) +{ + m_frequencyHz = hz; +} + +float32 b2MouseJoint::GetFrequency() const +{ + return m_frequencyHz; +} + +void b2MouseJoint::SetDampingRatio(float32 ratio) +{ + m_dampingRatio = ratio; +} + +float32 b2MouseJoint::GetDampingRatio() const +{ + return m_dampingRatio; +} + +void b2MouseJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b = m_bodyB; + + float32 mass = b->GetMass(); + + // Frequency + float32 omega = 2.0f * b2_pi * m_frequencyHz; + + // Damping coefficient + float32 d = 2.0f * mass * m_dampingRatio * omega; + + // Spring stiffness + float32 k = mass * (omega * omega); + + // magic formulas + // gamma has units of inverse mass. + // beta has units of inverse time. + b2Assert(d + step.dt * k > b2_epsilon); + m_gamma = step.dt * (d + step.dt * k); + if (m_gamma != 0.0f) + { + m_gamma = 1.0f / m_gamma; + } + m_beta = step.dt * k * m_gamma; + + // Compute the effective mass matrix. + b2Vec2 r = b2Mul(b->GetTransform().R, m_localAnchor - b->GetLocalCenter()); + + // K = [(1/m1 + 1/m2) * eye(2) - skew(r1) * invI1 * skew(r1) - skew(r2) * invI2 * skew(r2)] + // = [1/m1+1/m2 0 ] + invI1 * [r1.y*r1.y -r1.x*r1.y] + invI2 * [r1.y*r1.y -r1.x*r1.y] + // [ 0 1/m1+1/m2] [-r1.x*r1.y r1.x*r1.x] [-r1.x*r1.y r1.x*r1.x] + float32 invMass = b->m_invMass; + float32 invI = b->m_invI; + + b2Mat22 K1; + K1.col1.x = invMass; K1.col2.x = 0.0f; + K1.col1.y = 0.0f; K1.col2.y = invMass; + + b2Mat22 K2; + K2.col1.x = invI * r.y * r.y; K2.col2.x = -invI * r.x * r.y; + K2.col1.y = -invI * r.x * r.y; K2.col2.y = invI * r.x * r.x; + + b2Mat22 K = K1 + K2; + K.col1.x += m_gamma; + K.col2.y += m_gamma; + + m_mass = K.GetInverse(); + + m_C = b->m_sweep.c + r - m_target; + + // Cheat with some damping + b->m_angularVelocity *= 0.98f; + + // Warm starting. + m_impulse *= step.dtRatio; + b->m_linearVelocity += invMass * m_impulse; + b->m_angularVelocity += invI * b2Cross(r, m_impulse); +} + +void b2MouseJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b = m_bodyB; + + b2Vec2 r = b2Mul(b->GetTransform().R, m_localAnchor - b->GetLocalCenter()); + + // Cdot = v + cross(w, r) + b2Vec2 Cdot = b->m_linearVelocity + b2Cross(b->m_angularVelocity, r); + b2Vec2 impulse = b2Mul(m_mass, -(Cdot + m_beta * m_C + m_gamma * m_impulse)); + + b2Vec2 oldImpulse = m_impulse; + m_impulse += impulse; + float32 maxImpulse = step.dt * m_maxForce; + if (m_impulse.LengthSquared() > maxImpulse * maxImpulse) + { + m_impulse *= maxImpulse / m_impulse.Length(); + } + impulse = m_impulse - oldImpulse; + + b->m_linearVelocity += b->m_invMass * impulse; + b->m_angularVelocity += b->m_invI * b2Cross(r, impulse); +} + +b2Vec2 b2MouseJoint::GetAnchorA() const +{ + return m_target; +} + +b2Vec2 b2MouseJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchor); +} + +b2Vec2 b2MouseJoint::GetReactionForce(float32 inv_dt) const +{ + return inv_dt * m_impulse; +} + +float32 b2MouseJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * 0.0f; +} diff --git a/uppsrc/plugin/box2d/b2MouseJoint.h b/uppsrc/plugin/box2d/b2MouseJoint.h new file mode 100644 index 000000000..33bbd65ca --- /dev/null +++ b/uppsrc/plugin/box2d/b2MouseJoint.h @@ -0,0 +1,114 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_MOUSE_JOINT_H +#define B2_MOUSE_JOINT_H + +#include "b2Joint.h" + +/// Mouse joint definition. This requires a world target point, +/// tuning parameters, and the time step. +struct b2MouseJointDef : public b2JointDef +{ + b2MouseJointDef() + { + type = e_mouseJoint; + target.Set(0.0f, 0.0f); + maxForce = 0.0f; + frequencyHz = 5.0f; + dampingRatio = 0.7f; + } + + /// The initial world target point. This is assumed + /// to coincide with the body anchor initially. + b2Vec2 target; + + /// The maximum constraint force that can be exerted + /// to move the candidate body. Usually you will express + /// as some multiple of the weight (multiplier * mass * gravity). + float32 maxForce; + + /// The response speed. + float32 frequencyHz; + + /// The damping ratio. 0 = no damping, 1 = critical damping. + float32 dampingRatio; +}; + +/// A mouse joint is used to make a point on a body track a +/// specified world point. This a soft constraint with a maximum +/// force. This allows the constraint to stretch and without +/// applying huge forces. +/// NOTE: this joint is not documented in the manual because it was +/// developed to be used in the testbed. If you want to learn how to +/// use the mouse joint, look at the testbed. +class b2MouseJoint : public b2Joint +{ +public: + + /// Implements b2Joint. + b2Vec2 GetAnchorA() const; + + /// Implements b2Joint. + b2Vec2 GetAnchorB() const; + + /// Implements b2Joint. + b2Vec2 GetReactionForce(float32 inv_dt) const; + + /// Implements b2Joint. + float32 GetReactionTorque(float32 inv_dt) const; + + /// Use this to update the target point. + void SetTarget(const b2Vec2& target); + const b2Vec2& GetTarget() const; + + /// Set/get the maximum force in Newtons. + void SetMaxForce(float32 force); + float32 GetMaxForce() const; + + /// Set/get the frequency in Hertz. + void SetFrequency(float32 hz); + float32 GetFrequency() const; + + /// Set/get the damping ratio (dimensionless). + void SetDampingRatio(float32 ratio); + float32 GetDampingRatio() const; + +protected: + friend class b2Joint; + + b2MouseJoint(const b2MouseJointDef* def); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + bool SolvePositionConstraints(float32 baumgarte) { B2_NOT_USED(baumgarte); return true; } + + b2Vec2 m_localAnchor; + b2Vec2 m_target; + b2Vec2 m_impulse; + + b2Mat22 m_mass; // effective mass for point-to-point constraint. + b2Vec2 m_C; // position error + float32 m_maxForce; + float32 m_frequencyHz; + float32 m_dampingRatio; + float32 m_beta; + float32 m_gamma; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2PolygonAndCircleContact.cpp b/uppsrc/plugin/box2d/b2PolygonAndCircleContact.cpp new file mode 100644 index 000000000..f647c87b9 --- /dev/null +++ b/uppsrc/plugin/box2d/b2PolygonAndCircleContact.cpp @@ -0,0 +1,52 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2PolygonAndCircleContact.h" +#include "b2BlockAllocator.h" +#include "b2TimeOfImpact.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2WorldCallbacks.h" + +#include + +b2Contact* b2PolygonAndCircleContact::Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator) +{ + void* mem = allocator->Allocate(sizeof(b2PolygonAndCircleContact)); + return new (mem) b2PolygonAndCircleContact(fixtureA, fixtureB); +} + +void b2PolygonAndCircleContact::Destroy(b2Contact* contact, b2BlockAllocator* allocator) +{ + ((b2PolygonAndCircleContact*)contact)->~b2PolygonAndCircleContact(); + allocator->Free(contact, sizeof(b2PolygonAndCircleContact)); +} + +b2PolygonAndCircleContact::b2PolygonAndCircleContact(b2Fixture* fixtureA, b2Fixture* fixtureB) +: b2Contact(fixtureA, fixtureB) +{ + b2Assert(m_fixtureA->GetType() == b2Shape::e_polygon); + b2Assert(m_fixtureB->GetType() == b2Shape::e_circle); +} + +void b2PolygonAndCircleContact::Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB) +{ + b2CollidePolygonAndCircle( manifold, + (b2PolygonShape*)m_fixtureA->GetShape(), xfA, + (b2CircleShape*)m_fixtureB->GetShape(), xfB); +} diff --git a/uppsrc/plugin/box2d/b2PolygonAndCircleContact.h b/uppsrc/plugin/box2d/b2PolygonAndCircleContact.h new file mode 100644 index 000000000..7f43e6d46 --- /dev/null +++ b/uppsrc/plugin/box2d/b2PolygonAndCircleContact.h @@ -0,0 +1,38 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_POLYGON_AND_CIRCLE_CONTACT_H +#define B2_POLYGON_AND_CIRCLE_CONTACT_H + +#include "b2Contact.h" + +class b2BlockAllocator; + +class b2PolygonAndCircleContact : public b2Contact +{ +public: + static b2Contact* Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator); + static void Destroy(b2Contact* contact, b2BlockAllocator* allocator); + + b2PolygonAndCircleContact(b2Fixture* fixtureA, b2Fixture* fixtureB); + ~b2PolygonAndCircleContact() {} + + void Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB); +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2PolygonContact.cpp b/uppsrc/plugin/box2d/b2PolygonContact.cpp new file mode 100644 index 000000000..98070eaab --- /dev/null +++ b/uppsrc/plugin/box2d/b2PolygonContact.cpp @@ -0,0 +1,52 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2PolygonContact.h" +#include "b2BlockAllocator.h" +#include "b2TimeOfImpact.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2WorldCallbacks.h" + +#include + +b2Contact* b2PolygonContact::Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator) +{ + void* mem = allocator->Allocate(sizeof(b2PolygonContact)); + return new (mem) b2PolygonContact(fixtureA, fixtureB); +} + +void b2PolygonContact::Destroy(b2Contact* contact, b2BlockAllocator* allocator) +{ + ((b2PolygonContact*)contact)->~b2PolygonContact(); + allocator->Free(contact, sizeof(b2PolygonContact)); +} + +b2PolygonContact::b2PolygonContact(b2Fixture* fixtureA, b2Fixture* fixtureB) + : b2Contact(fixtureA, fixtureB) +{ + b2Assert(m_fixtureA->GetType() == b2Shape::e_polygon); + b2Assert(m_fixtureB->GetType() == b2Shape::e_polygon); +} + +void b2PolygonContact::Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB) +{ + b2CollidePolygons( manifold, + (b2PolygonShape*)m_fixtureA->GetShape(), xfA, + (b2PolygonShape*)m_fixtureB->GetShape(), xfB); +} diff --git a/uppsrc/plugin/box2d/b2PolygonContact.h b/uppsrc/plugin/box2d/b2PolygonContact.h new file mode 100644 index 000000000..e70e8458c --- /dev/null +++ b/uppsrc/plugin/box2d/b2PolygonContact.h @@ -0,0 +1,38 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_POLYGON_CONTACT_H +#define B2_POLYGON_CONTACT_H + +#include "b2Contact.h" + +class b2BlockAllocator; + +class b2PolygonContact : public b2Contact +{ +public: + static b2Contact* Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator); + static void Destroy(b2Contact* contact, b2BlockAllocator* allocator); + + b2PolygonContact(b2Fixture* fixtureA, b2Fixture* fixtureB); + ~b2PolygonContact() {} + + void Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB); +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2PolygonShape.cpp b/uppsrc/plugin/box2d/b2PolygonShape.cpp new file mode 100644 index 000000000..38ac5286c --- /dev/null +++ b/uppsrc/plugin/box2d/b2PolygonShape.cpp @@ -0,0 +1,434 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2PolygonShape.h" +#include + +b2Shape* b2PolygonShape::Clone(b2BlockAllocator* allocator) const +{ + void* mem = allocator->Allocate(sizeof(b2PolygonShape)); + b2PolygonShape* clone = new (mem) b2PolygonShape; + *clone = *this; + return clone; +} + +void b2PolygonShape::SetAsBox(float32 hx, float32 hy) +{ + m_vertexCount = 4; + m_vertices[0].Set(-hx, -hy); + m_vertices[1].Set( hx, -hy); + m_vertices[2].Set( hx, hy); + m_vertices[3].Set(-hx, hy); + m_normals[0].Set(0.0f, -1.0f); + m_normals[1].Set(1.0f, 0.0f); + m_normals[2].Set(0.0f, 1.0f); + m_normals[3].Set(-1.0f, 0.0f); + m_centroid.SetZero(); +} + +void b2PolygonShape::SetAsBox(float32 hx, float32 hy, const b2Vec2& center, float32 angle) +{ + m_vertexCount = 4; + m_vertices[0].Set(-hx, -hy); + m_vertices[1].Set( hx, -hy); + m_vertices[2].Set( hx, hy); + m_vertices[3].Set(-hx, hy); + m_normals[0].Set(0.0f, -1.0f); + m_normals[1].Set(1.0f, 0.0f); + m_normals[2].Set(0.0f, 1.0f); + m_normals[3].Set(-1.0f, 0.0f); + m_centroid = center; + + b2Transform xf; + xf.position = center; + xf.R.Set(angle); + + // Transform vertices and normals. + for (int32 i = 0; i < m_vertexCount; ++i) + { + m_vertices[i] = b2Mul(xf, m_vertices[i]); + m_normals[i] = b2Mul(xf.R, m_normals[i]); + } +} + +void b2PolygonShape::SetAsEdge(const b2Vec2& v1, const b2Vec2& v2) +{ + m_vertexCount = 2; + m_vertices[0] = v1; + m_vertices[1] = v2; + m_centroid = 0.5f * (v1 + v2); + m_normals[0] = b2Cross(v2 - v1, 1.0f); + m_normals[0].Normalize(); + m_normals[1] = -m_normals[0]; +} + +static b2Vec2 ComputeCentroid(const b2Vec2* vs, int32 count) +{ + b2Assert(count >= 2); + + b2Vec2 c; c.Set(0.0f, 0.0f); + float32 area = 0.0f; + + if (count == 2) + { + c = 0.5f * (vs[0] + vs[1]); + return c; + } + + // pRef is the reference point for forming triangles. + // It's location doesn't change the result (except for rounding error). + b2Vec2 pRef(0.0f, 0.0f); +#if 0 + // This code would put the reference point inside the polygon. + for (int32 i = 0; i < count; ++i) + { + pRef += vs[i]; + } + pRef *= 1.0f / count; +#endif + + const float32 inv3 = 1.0f / 3.0f; + + for (int32 i = 0; i < count; ++i) + { + // Triangle vertices. + b2Vec2 p1 = pRef; + b2Vec2 p2 = vs[i]; + b2Vec2 p3 = i + 1 < count ? vs[i+1] : vs[0]; + + b2Vec2 e1 = p2 - p1; + b2Vec2 e2 = p3 - p1; + + float32 D = b2Cross(e1, e2); + + float32 triangleArea = 0.5f * D; + area += triangleArea; + + // Area weighted centroid + c += triangleArea * inv3 * (p1 + p2 + p3); + } + + // Centroid + b2Assert(area > b2_epsilon); + c *= 1.0f / area; + return c; +} + +void b2PolygonShape::Set(const b2Vec2* vertices, int32 count) +{ + b2Assert(2 <= count && count <= b2_maxPolygonVertices); + m_vertexCount = count; + + // Copy vertices. + for (int32 i = 0; i < m_vertexCount; ++i) + { + m_vertices[i] = vertices[i]; + } + + // Compute normals. Ensure the edges have non-zero length. + for (int32 i = 0; i < m_vertexCount; ++i) + { + int32 i1 = i; + int32 i2 = i + 1 < m_vertexCount ? i + 1 : 0; + b2Vec2 edge = m_vertices[i2] - m_vertices[i1]; + b2Assert(edge.LengthSquared() > b2_epsilon * b2_epsilon); + m_normals[i] = b2Cross(edge, 1.0f); + m_normals[i].Normalize(); + } + +#ifdef _DEBUG + // Ensure the polygon is convex and the interior + // is to the left of each edge. + for (int32 i = 0; i < m_vertexCount; ++i) + { + int32 i1 = i; + int32 i2 = i + 1 < m_vertexCount ? i + 1 : 0; + b2Vec2 edge = m_vertices[i2] - m_vertices[i1]; + + for (int32 j = 0; j < m_vertexCount; ++j) + { + // Don't check vertices on the current edge. + if (j == i1 || j == i2) + { + continue; + } + + b2Vec2 r = m_vertices[j] - m_vertices[i1]; + + // Your polygon is non-convex (it has an indentation) or + // has colinear edges. + float32 s = b2Cross(edge, r); + b2Assert(s > 0.0f); + } + } +#endif + + // Compute the polygon centroid. + m_centroid = ComputeCentroid(m_vertices, m_vertexCount); +} + +bool b2PolygonShape::TestPoint(const b2Transform& xf, const b2Vec2& p) const +{ + b2Vec2 pLocal = b2MulT(xf.R, p - xf.position); + + for (int32 i = 0; i < m_vertexCount; ++i) + { + float32 dot = b2Dot(m_normals[i], pLocal - m_vertices[i]); + if (dot > 0.0f) + { + return false; + } + } + + return true; +} + +bool b2PolygonShape::RayCast(b2RayCastOutput* output, const b2RayCastInput& input, const b2Transform& xf) const +{ + // Put the ray into the polygon's frame of reference. + b2Vec2 p1 = b2MulT(xf.R, input.p1 - xf.position); + b2Vec2 p2 = b2MulT(xf.R, input.p2 - xf.position); + b2Vec2 d = p2 - p1; + + if (m_vertexCount == 2) + { + b2Vec2 v1 = m_vertices[0]; + b2Vec2 v2 = m_vertices[1]; + b2Vec2 normal = m_normals[0]; + + // q = p1 + t * d + // dot(normal, q - v1) = 0 + // dot(normal, p1 - v1) + t * dot(normal, d) = 0 + float32 numerator = b2Dot(normal, v1 - p1); + float32 denominator = b2Dot(normal, d); + + if (denominator == 0.0f) + { + return false; + } + + float32 t = numerator / denominator; + if (t < 0.0f || 1.0f < t) + { + return false; + } + + b2Vec2 q = p1 + t * d; + + // q = v1 + s * r + // s = dot(q - v1, r) / dot(r, r) + b2Vec2 r = v2 - v1; + float32 rr = b2Dot(r, r); + if (rr == 0.0f) + { + return false; + } + + float32 s = b2Dot(q - v1, r) / rr; + if (s < 0.0f || 1.0f < s) + { + return false; + } + + output->fraction = t; + if (numerator > 0.0f) + { + output->normal = -normal; + } + else + { + output->normal = normal; + } + return true; + } + else + { + float32 lower = 0.0f, upper = input.maxFraction; + + int32 index = -1; + + for (int32 i = 0; i < m_vertexCount; ++i) + { + // p = p1 + a * d + // dot(normal, p - v) = 0 + // dot(normal, p1 - v) + a * dot(normal, d) = 0 + float32 numerator = b2Dot(m_normals[i], m_vertices[i] - p1); + float32 denominator = b2Dot(m_normals[i], d); + + if (denominator == 0.0f) + { + if (numerator < 0.0f) + { + return false; + } + } + else + { + // Note: we want this predicate without division: + // lower < numerator / denominator, where denominator < 0 + // Since denominator < 0, we have to flip the inequality: + // lower < numerator / denominator <==> denominator * lower > numerator. + if (denominator < 0.0f && numerator < lower * denominator) + { + // Increase lower. + // The segment enters this half-space. + lower = numerator / denominator; + index = i; + } + else if (denominator > 0.0f && numerator < upper * denominator) + { + // Decrease upper. + // The segment exits this half-space. + upper = numerator / denominator; + } + } + + // The use of epsilon here causes the assert on lower to trip + // in some cases. Apparently the use of epsilon was to make edge + // shapes work, but now those are handled separately. + //if (upper < lower - b2_epsilon) + if (upper < lower) + { + return false; + } + } + + b2Assert(0.0f <= lower && lower <= input.maxFraction); + + if (index >= 0) + { + output->fraction = lower; + output->normal = b2Mul(xf.R, m_normals[index]); + return true; + } + } + + return false; +} + +void b2PolygonShape::ComputeAABB(b2AABB* aabb, const b2Transform& xf) const +{ + b2Vec2 lower = b2Mul(xf, m_vertices[0]); + b2Vec2 upper = lower; + + for (int32 i = 1; i < m_vertexCount; ++i) + { + b2Vec2 v = b2Mul(xf, m_vertices[i]); + lower = b2Min(lower, v); + upper = b2Max(upper, v); + } + + b2Vec2 r(m_radius, m_radius); + aabb->lowerBound = lower - r; + aabb->upperBound = upper + r; +} + +void b2PolygonShape::ComputeMass(b2MassData* massData, float32 density) const +{ + // Polygon mass, centroid, and inertia. + // Let rho be the polygon density in mass per unit area. + // Then: + // mass = rho * int(dA) + // centroid.x = (1/mass) * rho * int(x * dA) + // centroid.y = (1/mass) * rho * int(y * dA) + // I = rho * int((x*x + y*y) * dA) + // + // We can compute these integrals by summing all the integrals + // for each triangle of the polygon. To evaluate the integral + // for a single triangle, we make a change of variables to + // the (u,v) coordinates of the triangle: + // x = x0 + e1x * u + e2x * v + // y = y0 + e1y * u + e2y * v + // where 0 <= u && 0 <= v && u + v <= 1. + // + // We integrate u from [0,1-v] and then v from [0,1]. + // We also need to use the Jacobian of the transformation: + // D = cross(e1, e2) + // + // Simplification: triangle centroid = (1/3) * (p1 + p2 + p3) + // + // The rest of the derivation is handled by computer algebra. + + b2Assert(m_vertexCount >= 2); + + // A line segment has zero mass. + if (m_vertexCount == 2) + { + massData->center = 0.5f * (m_vertices[0] + m_vertices[1]); + massData->mass = 0.0f; + massData->I = 0.0f; + return; + } + + b2Vec2 center; center.Set(0.0f, 0.0f); + float32 area = 0.0f; + float32 I = 0.0f; + + // pRef is the reference point for forming triangles. + // It's location doesn't change the result (except for rounding error). + b2Vec2 pRef(0.0f, 0.0f); +#if 0 + // This code would put the reference point inside the polygon. + for (int32 i = 0; i < m_vertexCount; ++i) + { + pRef += m_vertices[i]; + } + pRef *= 1.0f / count; +#endif + + const float32 k_inv3 = 1.0f / 3.0f; + + for (int32 i = 0; i < m_vertexCount; ++i) + { + // Triangle vertices. + b2Vec2 p1 = pRef; + b2Vec2 p2 = m_vertices[i]; + b2Vec2 p3 = i + 1 < m_vertexCount ? m_vertices[i+1] : m_vertices[0]; + + b2Vec2 e1 = p2 - p1; + b2Vec2 e2 = p3 - p1; + + float32 D = b2Cross(e1, e2); + + float32 triangleArea = 0.5f * D; + area += triangleArea; + + // Area weighted centroid + center += triangleArea * k_inv3 * (p1 + p2 + p3); + + float32 px = p1.x, py = p1.y; + float32 ex1 = e1.x, ey1 = e1.y; + float32 ex2 = e2.x, ey2 = e2.y; + + float32 intx2 = k_inv3 * (0.25f * (ex1*ex1 + ex2*ex1 + ex2*ex2) + (px*ex1 + px*ex2)) + 0.5f*px*px; + float32 inty2 = k_inv3 * (0.25f * (ey1*ey1 + ey2*ey1 + ey2*ey2) + (py*ey1 + py*ey2)) + 0.5f*py*py; + + I += D * (intx2 + inty2); + } + + // Total mass + massData->mass = density * area; + + // Center of mass + b2Assert(area > b2_epsilon); + center *= 1.0f / area; + massData->center = center; + + // Inertia tensor relative to the local origin. + massData->I = density * I; +} diff --git a/uppsrc/plugin/box2d/b2PolygonShape.h b/uppsrc/plugin/box2d/b2PolygonShape.h new file mode 100644 index 000000000..0f6fe48b8 --- /dev/null +++ b/uppsrc/plugin/box2d/b2PolygonShape.h @@ -0,0 +1,131 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_POLYGON_SHAPE_H +#define B2_POLYGON_SHAPE_H + +#include "b2Shape.h" + +/// A convex polygon. It is assumed that the interior of the polygon is to +/// the left of each edge. +class b2PolygonShape : public b2Shape +{ +public: + b2PolygonShape(); + + /// Implement b2Shape. + b2Shape* Clone(b2BlockAllocator* allocator) const; + + /// Copy vertices. This assumes the vertices define a convex polygon. + /// It is assumed that the exterior is the the right of each edge. + void Set(const b2Vec2* vertices, int32 vertexCount); + + /// Build vertices to represent an axis-aligned box. + /// @param hx the half-width. + /// @param hy the half-height. + void SetAsBox(float32 hx, float32 hy); + + /// Build vertices to represent an oriented box. + /// @param hx the half-width. + /// @param hy the half-height. + /// @param center the center of the box in local coordinates. + /// @param angle the rotation of the box in local coordinates. + void SetAsBox(float32 hx, float32 hy, const b2Vec2& center, float32 angle); + + /// Set this as a single edge. + void SetAsEdge(const b2Vec2& v1, const b2Vec2& v2); + + /// @see b2Shape::TestPoint + bool TestPoint(const b2Transform& transform, const b2Vec2& p) const; + + /// Implement b2Shape. + bool RayCast(b2RayCastOutput* output, const b2RayCastInput& input, const b2Transform& transform) const; + + /// @see b2Shape::ComputeAABB + void ComputeAABB(b2AABB* aabb, const b2Transform& transform) const; + + /// @see b2Shape::ComputeMass + void ComputeMass(b2MassData* massData, float32 density) const; + + /// Get the supporting vertex index in the given direction. + int32 GetSupport(const b2Vec2& d) const; + + /// Get the supporting vertex in the given direction. + const b2Vec2& GetSupportVertex(const b2Vec2& d) const; + + /// Get the vertex count. + int32 GetVertexCount() const { return m_vertexCount; } + + /// Get a vertex by index. + const b2Vec2& GetVertex(int32 index) const; + + b2Vec2 m_centroid; + b2Vec2 m_vertices[b2_maxPolygonVertices]; + b2Vec2 m_normals[b2_maxPolygonVertices]; + int32 m_vertexCount; +}; + +inline b2PolygonShape::b2PolygonShape() +{ + m_type = e_polygon; + m_radius = b2_polygonRadius; + m_vertexCount = 0; + m_centroid.SetZero(); +} + +inline int32 b2PolygonShape::GetSupport(const b2Vec2& d) const +{ + int32 bestIndex = 0; + float32 bestValue = b2Dot(m_vertices[0], d); + for (int32 i = 1; i < m_vertexCount; ++i) + { + float32 value = b2Dot(m_vertices[i], d); + if (value > bestValue) + { + bestIndex = i; + bestValue = value; + } + } + + return bestIndex; +} + +inline const b2Vec2& b2PolygonShape::GetSupportVertex(const b2Vec2& d) const +{ + int32 bestIndex = 0; + float32 bestValue = b2Dot(m_vertices[0], d); + for (int32 i = 1; i < m_vertexCount; ++i) + { + float32 value = b2Dot(m_vertices[i], d); + if (value > bestValue) + { + bestIndex = i; + bestValue = value; + } + } + + return m_vertices[bestIndex]; +} + +inline const b2Vec2& b2PolygonShape::GetVertex(int32 index) const +{ + b2Assert(0 <= index && index < m_vertexCount); + return m_vertices[index]; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2PrismaticJoint.cpp b/uppsrc/plugin/box2d/b2PrismaticJoint.cpp new file mode 100644 index 000000000..8b7e810bf --- /dev/null +++ b/uppsrc/plugin/box2d/b2PrismaticJoint.cpp @@ -0,0 +1,586 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2PrismaticJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// Linear constraint (point-to-line) +// d = p2 - p1 = x2 + r2 - x1 - r1 +// C = dot(perp, d) +// Cdot = dot(d, cross(w1, perp)) + dot(perp, v2 + cross(w2, r2) - v1 - cross(w1, r1)) +// = -dot(perp, v1) - dot(cross(d + r1, perp), w1) + dot(perp, v2) + dot(cross(r2, perp), v2) +// J = [-perp, -cross(d + r1, perp), perp, cross(r2,perp)] +// +// Angular constraint +// C = a2 - a1 + a_initial +// Cdot = w2 - w1 +// J = [0 0 -1 0 0 1] +// +// K = J * invM * JT +// +// J = [-a -s1 a s2] +// [0 -1 0 1] +// a = perp +// s1 = cross(d + r1, a) = cross(p2 - x1, a) +// s2 = cross(r2, a) = cross(p2 - x2, a) + + +// Motor/Limit linear constraint +// C = dot(ax1, d) +// Cdot = = -dot(ax1, v1) - dot(cross(d + r1, ax1), w1) + dot(ax1, v2) + dot(cross(r2, ax1), v2) +// J = [-ax1 -cross(d+r1,ax1) ax1 cross(r2,ax1)] + +// Block Solver +// We develop a block solver that includes the joint limit. This makes the limit stiff (inelastic) even +// when the mass has poor distribution (leading to large torques about the joint anchor points). +// +// The Jacobian has 3 rows: +// J = [-uT -s1 uT s2] // linear +// [0 -1 0 1] // angular +// [-vT -a1 vT a2] // limit +// +// u = perp +// v = axis +// s1 = cross(d + r1, u), s2 = cross(r2, u) +// a1 = cross(d + r1, v), a2 = cross(r2, v) + +// M * (v2 - v1) = JT * df +// J * v2 = bias +// +// v2 = v1 + invM * JT * df +// J * (v1 + invM * JT * df) = bias +// K * df = bias - J * v1 = -Cdot +// K = J * invM * JT +// Cdot = J * v1 - bias +// +// Now solve for f2. +// df = f2 - f1 +// K * (f2 - f1) = -Cdot +// f2 = invK * (-Cdot) + f1 +// +// Clamp accumulated limit impulse. +// lower: f2(3) = max(f2(3), 0) +// upper: f2(3) = min(f2(3), 0) +// +// Solve for correct f2(1:2) +// K(1:2, 1:2) * f2(1:2) = -Cdot(1:2) - K(1:2,3) * f2(3) + K(1:2,1:3) * f1 +// = -Cdot(1:2) - K(1:2,3) * f2(3) + K(1:2,1:2) * f1(1:2) + K(1:2,3) * f1(3) +// K(1:2, 1:2) * f2(1:2) = -Cdot(1:2) - K(1:2,3) * (f2(3) - f1(3)) + K(1:2,1:2) * f1(1:2) +// f2(1:2) = invK(1:2,1:2) * (-Cdot(1:2) - K(1:2,3) * (f2(3) - f1(3))) + f1(1:2) +// +// Now compute impulse to be applied: +// df = f2 - f1 + +void b2PrismaticJointDef::Initialize(b2Body* b1, b2Body* b2, const b2Vec2& anchor, const b2Vec2& axis) +{ + bodyA = b1; + bodyB = b2; + localAnchorA = bodyA->GetLocalPoint(anchor); + localAnchorB = bodyB->GetLocalPoint(anchor); + localAxis1 = bodyA->GetLocalVector(axis); + referenceAngle = bodyB->GetAngle() - bodyA->GetAngle(); +} + +b2PrismaticJoint::b2PrismaticJoint(const b2PrismaticJointDef* def) +: b2Joint(def) +{ + m_localAnchor1 = def->localAnchorA; + m_localAnchor2 = def->localAnchorB; + m_localXAxis1 = def->localAxis1; + m_localYAxis1 = b2Cross(1.0f, m_localXAxis1); + m_refAngle = def->referenceAngle; + + m_impulse.SetZero(); + m_motorMass = 0.0; + m_motorImpulse = 0.0f; + + m_lowerTranslation = def->lowerTranslation; + m_upperTranslation = def->upperTranslation; + m_maxMotorForce = def->maxMotorForce; + m_motorSpeed = def->motorSpeed; + m_enableLimit = def->enableLimit; + m_enableMotor = def->enableMotor; + m_limitState = e_inactiveLimit; + + m_axis.SetZero(); + m_perp.SetZero(); +} + +void b2PrismaticJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + m_localCenterA = b1->GetLocalCenter(); + m_localCenterB = b2->GetLocalCenter(); + + b2Transform xf1 = b1->GetTransform(); + b2Transform xf2 = b2->GetTransform(); + + // Compute the effective masses. + b2Vec2 r1 = b2Mul(xf1.R, m_localAnchor1 - m_localCenterA); + b2Vec2 r2 = b2Mul(xf2.R, m_localAnchor2 - m_localCenterB); + b2Vec2 d = b2->m_sweep.c + r2 - b1->m_sweep.c - r1; + + m_invMassA = b1->m_invMass; + m_invIA = b1->m_invI; + m_invMassB = b2->m_invMass; + m_invIB = b2->m_invI; + + // Compute motor Jacobian and effective mass. + { + m_axis = b2Mul(xf1.R, m_localXAxis1); + m_a1 = b2Cross(d + r1, m_axis); + m_a2 = b2Cross(r2, m_axis); + + m_motorMass = m_invMassA + m_invMassB + m_invIA * m_a1 * m_a1 + m_invIB * m_a2 * m_a2; + if (m_motorMass > b2_epsilon) + { + m_motorMass = 1.0f / m_motorMass; + } + } + + // Prismatic constraint. + { + m_perp = b2Mul(xf1.R, m_localYAxis1); + + m_s1 = b2Cross(d + r1, m_perp); + m_s2 = b2Cross(r2, m_perp); + + float32 m1 = m_invMassA, m2 = m_invMassB; + float32 i1 = m_invIA, i2 = m_invIB; + + float32 k11 = m1 + m2 + i1 * m_s1 * m_s1 + i2 * m_s2 * m_s2; + float32 k12 = i1 * m_s1 + i2 * m_s2; + float32 k13 = i1 * m_s1 * m_a1 + i2 * m_s2 * m_a2; + float32 k22 = i1 + i2; + float32 k23 = i1 * m_a1 + i2 * m_a2; + float32 k33 = m1 + m2 + i1 * m_a1 * m_a1 + i2 * m_a2 * m_a2; + + m_K.col1.Set(k11, k12, k13); + m_K.col2.Set(k12, k22, k23); + m_K.col3.Set(k13, k23, k33); + } + + // Compute motor and limit terms. + if (m_enableLimit) + { + float32 jointTranslation = b2Dot(m_axis, d); + if (b2Abs(m_upperTranslation - m_lowerTranslation) < 2.0f * b2_linearSlop) + { + m_limitState = e_equalLimits; + } + else if (jointTranslation <= m_lowerTranslation) + { + if (m_limitState != e_atLowerLimit) + { + m_limitState = e_atLowerLimit; + m_impulse.z = 0.0f; + } + } + else if (jointTranslation >= m_upperTranslation) + { + if (m_limitState != e_atUpperLimit) + { + m_limitState = e_atUpperLimit; + m_impulse.z = 0.0f; + } + } + else + { + m_limitState = e_inactiveLimit; + m_impulse.z = 0.0f; + } + } + else + { + m_limitState = e_inactiveLimit; + m_impulse.z = 0.0f; + } + + if (m_enableMotor == false) + { + m_motorImpulse = 0.0f; + } + + if (step.warmStarting) + { + // Account for variable time step. + m_impulse *= step.dtRatio; + m_motorImpulse *= step.dtRatio; + + b2Vec2 P = m_impulse.x * m_perp + (m_motorImpulse + m_impulse.z) * m_axis; + float32 L1 = m_impulse.x * m_s1 + m_impulse.y + (m_motorImpulse + m_impulse.z) * m_a1; + float32 L2 = m_impulse.x * m_s2 + m_impulse.y + (m_motorImpulse + m_impulse.z) * m_a2; + + b1->m_linearVelocity -= m_invMassA * P; + b1->m_angularVelocity -= m_invIA * L1; + + b2->m_linearVelocity += m_invMassB * P; + b2->m_angularVelocity += m_invIB * L2; + } + else + { + m_impulse.SetZero(); + m_motorImpulse = 0.0f; + } +} + +void b2PrismaticJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 v1 = b1->m_linearVelocity; + float32 w1 = b1->m_angularVelocity; + b2Vec2 v2 = b2->m_linearVelocity; + float32 w2 = b2->m_angularVelocity; + + // Solve linear motor constraint. + if (m_enableMotor && m_limitState != e_equalLimits) + { + float32 Cdot = b2Dot(m_axis, v2 - v1) + m_a2 * w2 - m_a1 * w1; + float32 impulse = m_motorMass * (m_motorSpeed - Cdot); + float32 oldImpulse = m_motorImpulse; + float32 maxImpulse = step.dt * m_maxMotorForce; + m_motorImpulse = b2Clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse); + impulse = m_motorImpulse - oldImpulse; + + b2Vec2 P = impulse * m_axis; + float32 L1 = impulse * m_a1; + float32 L2 = impulse * m_a2; + + v1 -= m_invMassA * P; + w1 -= m_invIA * L1; + + v2 += m_invMassB * P; + w2 += m_invIB * L2; + } + + b2Vec2 Cdot1; + Cdot1.x = b2Dot(m_perp, v2 - v1) + m_s2 * w2 - m_s1 * w1; + Cdot1.y = w2 - w1; + + if (m_enableLimit && m_limitState != e_inactiveLimit) + { + // Solve prismatic and limit constraint in block form. + float32 Cdot2; + Cdot2 = b2Dot(m_axis, v2 - v1) + m_a2 * w2 - m_a1 * w1; + b2Vec3 Cdot(Cdot1.x, Cdot1.y, Cdot2); + + b2Vec3 f1 = m_impulse; + b2Vec3 df = m_K.Solve33(-Cdot); + m_impulse += df; + + if (m_limitState == e_atLowerLimit) + { + m_impulse.z = b2Max(m_impulse.z, 0.0f); + } + else if (m_limitState == e_atUpperLimit) + { + m_impulse.z = b2Min(m_impulse.z, 0.0f); + } + + // f2(1:2) = invK(1:2,1:2) * (-Cdot(1:2) - K(1:2,3) * (f2(3) - f1(3))) + f1(1:2) + b2Vec2 b = -Cdot1 - (m_impulse.z - f1.z) * b2Vec2(m_K.col3.x, m_K.col3.y); + b2Vec2 f2r = m_K.Solve22(b) + b2Vec2(f1.x, f1.y); + m_impulse.x = f2r.x; + m_impulse.y = f2r.y; + + df = m_impulse - f1; + + b2Vec2 P = df.x * m_perp + df.z * m_axis; + float32 L1 = df.x * m_s1 + df.y + df.z * m_a1; + float32 L2 = df.x * m_s2 + df.y + df.z * m_a2; + + v1 -= m_invMassA * P; + w1 -= m_invIA * L1; + + v2 += m_invMassB * P; + w2 += m_invIB * L2; + } + else + { + // Limit is inactive, just solve the prismatic constraint in block form. + b2Vec2 df = m_K.Solve22(-Cdot1); + m_impulse.x += df.x; + m_impulse.y += df.y; + + b2Vec2 P = df.x * m_perp; + float32 L1 = df.x * m_s1 + df.y; + float32 L2 = df.x * m_s2 + df.y; + + v1 -= m_invMassA * P; + w1 -= m_invIA * L1; + + v2 += m_invMassB * P; + w2 += m_invIB * L2; + } + + b1->m_linearVelocity = v1; + b1->m_angularVelocity = w1; + b2->m_linearVelocity = v2; + b2->m_angularVelocity = w2; +} + +bool b2PrismaticJoint::SolvePositionConstraints(float32 baumgarte) +{ + B2_NOT_USED(baumgarte); + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 c1 = b1->m_sweep.c; + float32 a1 = b1->m_sweep.a; + + b2Vec2 c2 = b2->m_sweep.c; + float32 a2 = b2->m_sweep.a; + + // Solve linear limit constraint. + float32 linearError = 0.0f, angularError = 0.0f; + bool active = false; + float32 C2 = 0.0f; + + b2Mat22 R1(a1), R2(a2); + + b2Vec2 r1 = b2Mul(R1, m_localAnchor1 - m_localCenterA); + b2Vec2 r2 = b2Mul(R2, m_localAnchor2 - m_localCenterB); + b2Vec2 d = c2 + r2 - c1 - r1; + + if (m_enableLimit) + { + m_axis = b2Mul(R1, m_localXAxis1); + + m_a1 = b2Cross(d + r1, m_axis); + m_a2 = b2Cross(r2, m_axis); + + float32 translation = b2Dot(m_axis, d); + if (b2Abs(m_upperTranslation - m_lowerTranslation) < 2.0f * b2_linearSlop) + { + // Prevent large angular corrections + C2 = b2Clamp(translation, -b2_maxLinearCorrection, b2_maxLinearCorrection); + linearError = b2Abs(translation); + active = true; + } + else if (translation <= m_lowerTranslation) + { + // Prevent large linear corrections and allow some slop. + C2 = b2Clamp(translation - m_lowerTranslation + b2_linearSlop, -b2_maxLinearCorrection, 0.0f); + linearError = m_lowerTranslation - translation; + active = true; + } + else if (translation >= m_upperTranslation) + { + // Prevent large linear corrections and allow some slop. + C2 = b2Clamp(translation - m_upperTranslation - b2_linearSlop, 0.0f, b2_maxLinearCorrection); + linearError = translation - m_upperTranslation; + active = true; + } + } + + m_perp = b2Mul(R1, m_localYAxis1); + + m_s1 = b2Cross(d + r1, m_perp); + m_s2 = b2Cross(r2, m_perp); + + b2Vec3 impulse; + b2Vec2 C1; + C1.x = b2Dot(m_perp, d); + C1.y = a2 - a1 - m_refAngle; + + linearError = b2Max(linearError, b2Abs(C1.x)); + angularError = b2Abs(C1.y); + + if (active) + { + float32 m1 = m_invMassA, m2 = m_invMassB; + float32 i1 = m_invIA, i2 = m_invIB; + + float32 k11 = m1 + m2 + i1 * m_s1 * m_s1 + i2 * m_s2 * m_s2; + float32 k12 = i1 * m_s1 + i2 * m_s2; + float32 k13 = i1 * m_s1 * m_a1 + i2 * m_s2 * m_a2; + float32 k22 = i1 + i2; + float32 k23 = i1 * m_a1 + i2 * m_a2; + float32 k33 = m1 + m2 + i1 * m_a1 * m_a1 + i2 * m_a2 * m_a2; + + m_K.col1.Set(k11, k12, k13); + m_K.col2.Set(k12, k22, k23); + m_K.col3.Set(k13, k23, k33); + + b2Vec3 C; + C.x = C1.x; + C.y = C1.y; + C.z = C2; + + impulse = m_K.Solve33(-C); + } + else + { + float32 m1 = m_invMassA, m2 = m_invMassB; + float32 i1 = m_invIA, i2 = m_invIB; + + float32 k11 = m1 + m2 + i1 * m_s1 * m_s1 + i2 * m_s2 * m_s2; + float32 k12 = i1 * m_s1 + i2 * m_s2; + float32 k22 = i1 + i2; + + m_K.col1.Set(k11, k12, 0.0f); + m_K.col2.Set(k12, k22, 0.0f); + + b2Vec2 impulse1 = m_K.Solve22(-C1); + impulse.x = impulse1.x; + impulse.y = impulse1.y; + impulse.z = 0.0f; + } + + b2Vec2 P = impulse.x * m_perp + impulse.z * m_axis; + float32 L1 = impulse.x * m_s1 + impulse.y + impulse.z * m_a1; + float32 L2 = impulse.x * m_s2 + impulse.y + impulse.z * m_a2; + + c1 -= m_invMassA * P; + a1 -= m_invIA * L1; + c2 += m_invMassB * P; + a2 += m_invIB * L2; + + // TODO_ERIN remove need for this. + b1->m_sweep.c = c1; + b1->m_sweep.a = a1; + b2->m_sweep.c = c2; + b2->m_sweep.a = a2; + b1->SynchronizeTransform(); + b2->SynchronizeTransform(); + + return linearError <= b2_linearSlop && angularError <= b2_angularSlop; +} + +b2Vec2 b2PrismaticJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchor1); +} + +b2Vec2 b2PrismaticJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchor2); +} + +b2Vec2 b2PrismaticJoint::GetReactionForce(float32 inv_dt) const +{ + return inv_dt * (m_impulse.x * m_perp + (m_motorImpulse + m_impulse.z) * m_axis); +} + +float32 b2PrismaticJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_impulse.y; +} + +float32 b2PrismaticJoint::GetJointTranslation() const +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 p1 = b1->GetWorldPoint(m_localAnchor1); + b2Vec2 p2 = b2->GetWorldPoint(m_localAnchor2); + b2Vec2 d = p2 - p1; + b2Vec2 axis = b1->GetWorldVector(m_localXAxis1); + + float32 translation = b2Dot(d, axis); + return translation; +} + +float32 b2PrismaticJoint::GetJointSpeed() const +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + b2Vec2 p1 = b1->m_sweep.c + r1; + b2Vec2 p2 = b2->m_sweep.c + r2; + b2Vec2 d = p2 - p1; + b2Vec2 axis = b1->GetWorldVector(m_localXAxis1); + + b2Vec2 v1 = b1->m_linearVelocity; + b2Vec2 v2 = b2->m_linearVelocity; + float32 w1 = b1->m_angularVelocity; + float32 w2 = b2->m_angularVelocity; + + float32 speed = b2Dot(d, b2Cross(w1, axis)) + b2Dot(axis, v2 + b2Cross(w2, r2) - v1 - b2Cross(w1, r1)); + return speed; +} + +bool b2PrismaticJoint::IsLimitEnabled() const +{ + return m_enableLimit; +} + +void b2PrismaticJoint::EnableLimit(bool flag) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableLimit = flag; +} + +float32 b2PrismaticJoint::GetLowerLimit() const +{ + return m_lowerTranslation; +} + +float32 b2PrismaticJoint::GetUpperLimit() const +{ + return m_upperTranslation; +} + +void b2PrismaticJoint::SetLimits(float32 lower, float32 upper) +{ + b2Assert(lower <= upper); + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_lowerTranslation = lower; + m_upperTranslation = upper; +} + +bool b2PrismaticJoint::IsMotorEnabled() const +{ + return m_enableMotor; +} + +void b2PrismaticJoint::EnableMotor(bool flag) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableMotor = flag; +} + +void b2PrismaticJoint::SetMotorSpeed(float32 speed) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_motorSpeed = speed; +} + +void b2PrismaticJoint::SetMaxMotorForce(float32 force) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_maxMotorForce = force; +} + +float32 b2PrismaticJoint::GetMotorForce() const +{ + return m_motorImpulse; +} diff --git a/uppsrc/plugin/box2d/b2PrismaticJoint.h b/uppsrc/plugin/box2d/b2PrismaticJoint.h new file mode 100644 index 000000000..68b49440c --- /dev/null +++ b/uppsrc/plugin/box2d/b2PrismaticJoint.h @@ -0,0 +1,175 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_PRISMATIC_JOINT_H +#define B2_PRISMATIC_JOINT_H + +#include "b2Joint.h" + +/// Prismatic joint definition. This requires defining a line of +/// motion using an axis and an anchor point. The definition uses local +/// anchor points and a local axis so that the initial configuration +/// can violate the constraint slightly. The joint translation is zero +/// when the local anchor points coincide in world space. Using local +/// anchors and a local axis helps when saving and loading a game. +/// @warning at least one body should by dynamic with a non-fixed rotation. +struct b2PrismaticJointDef : public b2JointDef +{ + b2PrismaticJointDef() + { + type = e_prismaticJoint; + localAnchorA.SetZero(); + localAnchorB.SetZero(); + localAxis1.Set(1.0f, 0.0f); + referenceAngle = 0.0f; + enableLimit = false; + lowerTranslation = 0.0f; + upperTranslation = 0.0f; + enableMotor = false; + maxMotorForce = 0.0f; + motorSpeed = 0.0f; + } + + /// Initialize the bodies, anchors, axis, and reference angle using the world + /// anchor and world axis. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor, const b2Vec2& axis); + + /// The local anchor point relative to body1's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to body2's origin. + b2Vec2 localAnchorB; + + /// The local translation axis in body1. + b2Vec2 localAxis1; + + /// The constrained angle between the bodies: body2_angle - body1_angle. + float32 referenceAngle; + + /// Enable/disable the joint limit. + bool enableLimit; + + /// The lower translation limit, usually in meters. + float32 lowerTranslation; + + /// The upper translation limit, usually in meters. + float32 upperTranslation; + + /// Enable/disable the joint motor. + bool enableMotor; + + /// The maximum motor torque, usually in N-m. + float32 maxMotorForce; + + /// The desired motor speed in radians per second. + float32 motorSpeed; +}; + +/// A prismatic joint. This joint provides one degree of freedom: translation +/// along an axis fixed in body1. Relative rotation is prevented. You can +/// use a joint limit to restrict the range of motion and a joint motor to +/// drive the motion or to model joint friction. +class b2PrismaticJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const; + b2Vec2 GetAnchorB() const; + + b2Vec2 GetReactionForce(float32 inv_dt) const; + float32 GetReactionTorque(float32 inv_dt) const; + + /// Get the current joint translation, usually in meters. + float32 GetJointTranslation() const; + + /// Get the current joint translation speed, usually in meters per second. + float32 GetJointSpeed() const; + + /// Is the joint limit enabled? + bool IsLimitEnabled() const; + + /// Enable/disable the joint limit. + void EnableLimit(bool flag); + + /// Get the lower joint limit, usually in meters. + float32 GetLowerLimit() const; + + /// Get the upper joint limit, usually in meters. + float32 GetUpperLimit() const; + + /// Set the joint limits, usually in meters. + void SetLimits(float32 lower, float32 upper); + + /// Is the joint motor enabled? + bool IsMotorEnabled() const; + + /// Enable/disable the joint motor. + void EnableMotor(bool flag); + + /// Set the motor speed, usually in meters per second. + void SetMotorSpeed(float32 speed); + + /// Get the motor speed, usually in meters per second. + float32 GetMotorSpeed() const; + + /// Set the maximum motor force, usually in N. + void SetMaxMotorForce(float32 force); + + /// Get the current motor force, usually in N. + float32 GetMotorForce() const; + +protected: + friend class b2Joint; + friend class b2GearJoint; + b2PrismaticJoint(const b2PrismaticJointDef* def); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + bool SolvePositionConstraints(float32 baumgarte); + + b2Vec2 m_localAnchor1; + b2Vec2 m_localAnchor2; + b2Vec2 m_localXAxis1; + b2Vec2 m_localYAxis1; + float32 m_refAngle; + + b2Vec2 m_axis, m_perp; + float32 m_s1, m_s2; + float32 m_a1, m_a2; + + b2Mat33 m_K; + b2Vec3 m_impulse; + + float32 m_motorMass; // effective mass for motor/limit translational constraint. + float32 m_motorImpulse; + + float32 m_lowerTranslation; + float32 m_upperTranslation; + float32 m_maxMotorForce; + float32 m_motorSpeed; + + bool m_enableLimit; + bool m_enableMotor; + b2LimitState m_limitState; +}; + +inline float32 b2PrismaticJoint::GetMotorSpeed() const +{ + return m_motorSpeed; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2PulleyJoint.cpp b/uppsrc/plugin/box2d/b2PulleyJoint.cpp new file mode 100644 index 000000000..0a5cd39f5 --- /dev/null +++ b/uppsrc/plugin/box2d/b2PulleyJoint.cpp @@ -0,0 +1,427 @@ +/* +* Copyright (c) 2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2PulleyJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// Pulley: +// length1 = norm(p1 - s1) +// length2 = norm(p2 - s2) +// C0 = (length1 + ratio * length2)_initial +// C = C0 - (length1 + ratio * length2) >= 0 +// u1 = (p1 - s1) / norm(p1 - s1) +// u2 = (p2 - s2) / norm(p2 - s2) +// Cdot = -dot(u1, v1 + cross(w1, r1)) - ratio * dot(u2, v2 + cross(w2, r2)) +// J = -[u1 cross(r1, u1) ratio * u2 ratio * cross(r2, u2)] +// K = J * invM * JT +// = invMass1 + invI1 * cross(r1, u1)^2 + ratio^2 * (invMass2 + invI2 * cross(r2, u2)^2) +// +// Limit: +// C = maxLength - length +// u = (p - s) / norm(p - s) +// Cdot = -dot(u, v + cross(w, r)) +// K = invMass + invI * cross(r, u)^2 +// 0 <= impulse + +void b2PulleyJointDef::Initialize(b2Body* b1, b2Body* b2, + const b2Vec2& ga1, const b2Vec2& ga2, + const b2Vec2& anchor1, const b2Vec2& anchor2, + float32 r) +{ + bodyA = b1; + bodyB = b2; + groundAnchorA = ga1; + groundAnchorB = ga2; + localAnchorA = bodyA->GetLocalPoint(anchor1); + localAnchorB = bodyB->GetLocalPoint(anchor2); + b2Vec2 d1 = anchor1 - ga1; + lengthA = d1.Length(); + b2Vec2 d2 = anchor2 - ga2; + lengthB = d2.Length(); + ratio = r; + b2Assert(ratio > b2_epsilon); + float32 C = lengthA + ratio * lengthB; + maxLengthA = C - ratio * b2_minPulleyLength; + maxLengthB = (C - b2_minPulleyLength) / ratio; +} + +b2PulleyJoint::b2PulleyJoint(const b2PulleyJointDef* def) +: b2Joint(def) +{ + m_groundAnchor1 = def->groundAnchorA; + m_groundAnchor2 = def->groundAnchorB; + m_localAnchor1 = def->localAnchorA; + m_localAnchor2 = def->localAnchorB; + + b2Assert(def->ratio != 0.0f); + m_ratio = def->ratio; + + m_constant = def->lengthA + m_ratio * def->lengthB; + + m_maxLength1 = b2Min(def->maxLengthA, m_constant - m_ratio * b2_minPulleyLength); + m_maxLength2 = b2Min(def->maxLengthB, (m_constant - b2_minPulleyLength) / m_ratio); + + m_impulse = 0.0f; + m_limitImpulse1 = 0.0f; + m_limitImpulse2 = 0.0f; +} + +void b2PulleyJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + b2Vec2 p1 = b1->m_sweep.c + r1; + b2Vec2 p2 = b2->m_sweep.c + r2; + + b2Vec2 s1 = m_groundAnchor1; + b2Vec2 s2 = m_groundAnchor2; + + // Get the pulley axes. + m_u1 = p1 - s1; + m_u2 = p2 - s2; + + float32 length1 = m_u1.Length(); + float32 length2 = m_u2.Length(); + + if (length1 > b2_linearSlop) + { + m_u1 *= 1.0f / length1; + } + else + { + m_u1.SetZero(); + } + + if (length2 > b2_linearSlop) + { + m_u2 *= 1.0f / length2; + } + else + { + m_u2.SetZero(); + } + + float32 C = m_constant - length1 - m_ratio * length2; + if (C > 0.0f) + { + m_state = e_inactiveLimit; + m_impulse = 0.0f; + } + else + { + m_state = e_atUpperLimit; + } + + if (length1 < m_maxLength1) + { + m_limitState1 = e_inactiveLimit; + m_limitImpulse1 = 0.0f; + } + else + { + m_limitState1 = e_atUpperLimit; + } + + if (length2 < m_maxLength2) + { + m_limitState2 = e_inactiveLimit; + m_limitImpulse2 = 0.0f; + } + else + { + m_limitState2 = e_atUpperLimit; + } + + // Compute effective mass. + float32 cr1u1 = b2Cross(r1, m_u1); + float32 cr2u2 = b2Cross(r2, m_u2); + + m_limitMass1 = b1->m_invMass + b1->m_invI * cr1u1 * cr1u1; + m_limitMass2 = b2->m_invMass + b2->m_invI * cr2u2 * cr2u2; + m_pulleyMass = m_limitMass1 + m_ratio * m_ratio * m_limitMass2; + b2Assert(m_limitMass1 > b2_epsilon); + b2Assert(m_limitMass2 > b2_epsilon); + b2Assert(m_pulleyMass > b2_epsilon); + m_limitMass1 = 1.0f / m_limitMass1; + m_limitMass2 = 1.0f / m_limitMass2; + m_pulleyMass = 1.0f / m_pulleyMass; + + if (step.warmStarting) + { + // Scale impulses to support variable time steps. + m_impulse *= step.dtRatio; + m_limitImpulse1 *= step.dtRatio; + m_limitImpulse2 *= step.dtRatio; + + // Warm starting. + b2Vec2 P1 = -(m_impulse + m_limitImpulse1) * m_u1; + b2Vec2 P2 = (-m_ratio * m_impulse - m_limitImpulse2) * m_u2; + b1->m_linearVelocity += b1->m_invMass * P1; + b1->m_angularVelocity += b1->m_invI * b2Cross(r1, P1); + b2->m_linearVelocity += b2->m_invMass * P2; + b2->m_angularVelocity += b2->m_invI * b2Cross(r2, P2); + } + else + { + m_impulse = 0.0f; + m_limitImpulse1 = 0.0f; + m_limitImpulse2 = 0.0f; + } +} + +void b2PulleyJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + B2_NOT_USED(step); + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + if (m_state == e_atUpperLimit) + { + b2Vec2 v1 = b1->m_linearVelocity + b2Cross(b1->m_angularVelocity, r1); + b2Vec2 v2 = b2->m_linearVelocity + b2Cross(b2->m_angularVelocity, r2); + + float32 Cdot = -b2Dot(m_u1, v1) - m_ratio * b2Dot(m_u2, v2); + float32 impulse = m_pulleyMass * (-Cdot); + float32 oldImpulse = m_impulse; + m_impulse = b2Max(0.0f, m_impulse + impulse); + impulse = m_impulse - oldImpulse; + + b2Vec2 P1 = -impulse * m_u1; + b2Vec2 P2 = -m_ratio * impulse * m_u2; + b1->m_linearVelocity += b1->m_invMass * P1; + b1->m_angularVelocity += b1->m_invI * b2Cross(r1, P1); + b2->m_linearVelocity += b2->m_invMass * P2; + b2->m_angularVelocity += b2->m_invI * b2Cross(r2, P2); + } + + if (m_limitState1 == e_atUpperLimit) + { + b2Vec2 v1 = b1->m_linearVelocity + b2Cross(b1->m_angularVelocity, r1); + + float32 Cdot = -b2Dot(m_u1, v1); + float32 impulse = -m_limitMass1 * Cdot; + float32 oldImpulse = m_limitImpulse1; + m_limitImpulse1 = b2Max(0.0f, m_limitImpulse1 + impulse); + impulse = m_limitImpulse1 - oldImpulse; + + b2Vec2 P1 = -impulse * m_u1; + b1->m_linearVelocity += b1->m_invMass * P1; + b1->m_angularVelocity += b1->m_invI * b2Cross(r1, P1); + } + + if (m_limitState2 == e_atUpperLimit) + { + b2Vec2 v2 = b2->m_linearVelocity + b2Cross(b2->m_angularVelocity, r2); + + float32 Cdot = -b2Dot(m_u2, v2); + float32 impulse = -m_limitMass2 * Cdot; + float32 oldImpulse = m_limitImpulse2; + m_limitImpulse2 = b2Max(0.0f, m_limitImpulse2 + impulse); + impulse = m_limitImpulse2 - oldImpulse; + + b2Vec2 P2 = -impulse * m_u2; + b2->m_linearVelocity += b2->m_invMass * P2; + b2->m_angularVelocity += b2->m_invI * b2Cross(r2, P2); + } +} + +bool b2PulleyJoint::SolvePositionConstraints(float32 baumgarte) +{ + B2_NOT_USED(baumgarte); + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 s1 = m_groundAnchor1; + b2Vec2 s2 = m_groundAnchor2; + + float32 linearError = 0.0f; + + if (m_state == e_atUpperLimit) + { + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + b2Vec2 p1 = b1->m_sweep.c + r1; + b2Vec2 p2 = b2->m_sweep.c + r2; + + // Get the pulley axes. + m_u1 = p1 - s1; + m_u2 = p2 - s2; + + float32 length1 = m_u1.Length(); + float32 length2 = m_u2.Length(); + + if (length1 > b2_linearSlop) + { + m_u1 *= 1.0f / length1; + } + else + { + m_u1.SetZero(); + } + + if (length2 > b2_linearSlop) + { + m_u2 *= 1.0f / length2; + } + else + { + m_u2.SetZero(); + } + + float32 C = m_constant - length1 - m_ratio * length2; + linearError = b2Max(linearError, -C); + + C = b2Clamp(C + b2_linearSlop, -b2_maxLinearCorrection, 0.0f); + float32 impulse = -m_pulleyMass * C; + + b2Vec2 P1 = -impulse * m_u1; + b2Vec2 P2 = -m_ratio * impulse * m_u2; + + b1->m_sweep.c += b1->m_invMass * P1; + b1->m_sweep.a += b1->m_invI * b2Cross(r1, P1); + b2->m_sweep.c += b2->m_invMass * P2; + b2->m_sweep.a += b2->m_invI * b2Cross(r2, P2); + + b1->SynchronizeTransform(); + b2->SynchronizeTransform(); + } + + if (m_limitState1 == e_atUpperLimit) + { + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 p1 = b1->m_sweep.c + r1; + + m_u1 = p1 - s1; + float32 length1 = m_u1.Length(); + + if (length1 > b2_linearSlop) + { + m_u1 *= 1.0f / length1; + } + else + { + m_u1.SetZero(); + } + + float32 C = m_maxLength1 - length1; + linearError = b2Max(linearError, -C); + C = b2Clamp(C + b2_linearSlop, -b2_maxLinearCorrection, 0.0f); + float32 impulse = -m_limitMass1 * C; + + b2Vec2 P1 = -impulse * m_u1; + b1->m_sweep.c += b1->m_invMass * P1; + b1->m_sweep.a += b1->m_invI * b2Cross(r1, P1); + + b1->SynchronizeTransform(); + } + + if (m_limitState2 == e_atUpperLimit) + { + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + b2Vec2 p2 = b2->m_sweep.c + r2; + + m_u2 = p2 - s2; + float32 length2 = m_u2.Length(); + + if (length2 > b2_linearSlop) + { + m_u2 *= 1.0f / length2; + } + else + { + m_u2.SetZero(); + } + + float32 C = m_maxLength2 - length2; + linearError = b2Max(linearError, -C); + C = b2Clamp(C + b2_linearSlop, -b2_maxLinearCorrection, 0.0f); + float32 impulse = -m_limitMass2 * C; + + b2Vec2 P2 = -impulse * m_u2; + b2->m_sweep.c += b2->m_invMass * P2; + b2->m_sweep.a += b2->m_invI * b2Cross(r2, P2); + + b2->SynchronizeTransform(); + } + + return linearError < b2_linearSlop; +} + +b2Vec2 b2PulleyJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchor1); +} + +b2Vec2 b2PulleyJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchor2); +} + +b2Vec2 b2PulleyJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 P = m_impulse * m_u2; + return inv_dt * P; +} + +float32 b2PulleyJoint::GetReactionTorque(float32 inv_dt) const +{ + B2_NOT_USED(inv_dt); + return 0.0f; +} + +b2Vec2 b2PulleyJoint::GetGroundAnchorA() const +{ + return m_groundAnchor1; +} + +b2Vec2 b2PulleyJoint::GetGroundAnchorB() const +{ + return m_groundAnchor2; +} + +float32 b2PulleyJoint::GetLength1() const +{ + b2Vec2 p = m_bodyA->GetWorldPoint(m_localAnchor1); + b2Vec2 s = m_groundAnchor1; + b2Vec2 d = p - s; + return d.Length(); +} + +float32 b2PulleyJoint::GetLength2() const +{ + b2Vec2 p = m_bodyB->GetWorldPoint(m_localAnchor2); + b2Vec2 s = m_groundAnchor2; + b2Vec2 d = p - s; + return d.Length(); +} + +float32 b2PulleyJoint::GetRatio() const +{ + return m_ratio; +} diff --git a/uppsrc/plugin/box2d/b2PulleyJoint.h b/uppsrc/plugin/box2d/b2PulleyJoint.h new file mode 100644 index 000000000..dbccf0db1 --- /dev/null +++ b/uppsrc/plugin/box2d/b2PulleyJoint.h @@ -0,0 +1,148 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_PULLEY_JOINT_H +#define B2_PULLEY_JOINT_H + +#include "b2Joint.h" + +const float32 b2_minPulleyLength = 2.0f; + +/// Pulley joint definition. This requires two ground anchors, +/// two dynamic body anchor points, max lengths for each side, +/// and a pulley ratio. +struct b2PulleyJointDef : public b2JointDef +{ + b2PulleyJointDef() + { + type = e_pulleyJoint; + groundAnchorA.Set(-1.0f, 1.0f); + groundAnchorB.Set(1.0f, 1.0f); + localAnchorA.Set(-1.0f, 0.0f); + localAnchorB.Set(1.0f, 0.0f); + lengthA = 0.0f; + maxLengthA = 0.0f; + lengthB = 0.0f; + maxLengthB = 0.0f; + ratio = 1.0f; + collideConnected = true; + } + + /// Initialize the bodies, anchors, lengths, max lengths, and ratio using the world anchors. + void Initialize(b2Body* bodyA, b2Body* bodyB, + const b2Vec2& groundAnchorA, const b2Vec2& groundAnchorB, + const b2Vec2& anchorA, const b2Vec2& anchorB, + float32 ratio); + + /// The first ground anchor in world coordinates. This point never moves. + b2Vec2 groundAnchorA; + + /// The second ground anchor in world coordinates. This point never moves. + b2Vec2 groundAnchorB; + + /// The local anchor point relative to bodyA's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to bodyB's origin. + b2Vec2 localAnchorB; + + /// The a reference length for the segment attached to bodyA. + float32 lengthA; + + /// The maximum length of the segment attached to bodyA. + float32 maxLengthA; + + /// The a reference length for the segment attached to bodyB. + float32 lengthB; + + /// The maximum length of the segment attached to bodyB. + float32 maxLengthB; + + /// The pulley ratio, used to simulate a block-and-tackle. + float32 ratio; +}; + +/// The pulley joint is connected to two bodies and two fixed ground points. +/// The pulley supports a ratio such that: +/// length1 + ratio * length2 <= constant +/// Yes, the force transmitted is scaled by the ratio. +/// The pulley also enforces a maximum length limit on both sides. This is +/// useful to prevent one side of the pulley hitting the top. +class b2PulleyJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const; + b2Vec2 GetAnchorB() const; + + b2Vec2 GetReactionForce(float32 inv_dt) const; + float32 GetReactionTorque(float32 inv_dt) const; + + /// Get the first ground anchor. + b2Vec2 GetGroundAnchorA() const; + + /// Get the second ground anchor. + b2Vec2 GetGroundAnchorB() const; + + /// Get the current length of the segment attached to body1. + float32 GetLength1() const; + + /// Get the current length of the segment attached to body2. + float32 GetLength2() const; + + /// Get the pulley ratio. + float32 GetRatio() const; + +protected: + + friend class b2Joint; + b2PulleyJoint(const b2PulleyJointDef* data); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + bool SolvePositionConstraints(float32 baumgarte); + + b2Vec2 m_groundAnchor1; + b2Vec2 m_groundAnchor2; + b2Vec2 m_localAnchor1; + b2Vec2 m_localAnchor2; + + b2Vec2 m_u1; + b2Vec2 m_u2; + + float32 m_constant; + float32 m_ratio; + + float32 m_maxLength1; + float32 m_maxLength2; + + // Effective masses + float32 m_pulleyMass; + float32 m_limitMass1; + float32 m_limitMass2; + + // Impulses for accumulation/warm starting. + float32 m_impulse; + float32 m_limitImpulse1; + float32 m_limitImpulse2; + + b2LimitState m_state; + b2LimitState m_limitState1; + b2LimitState m_limitState2; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2RevoluteJoint.cpp b/uppsrc/plugin/box2d/b2RevoluteJoint.cpp new file mode 100644 index 000000000..097b7f714 --- /dev/null +++ b/uppsrc/plugin/box2d/b2RevoluteJoint.cpp @@ -0,0 +1,478 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2RevoluteJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// Point-to-point constraint +// C = p2 - p1 +// Cdot = v2 - v1 +// = v2 + cross(w2, r2) - v1 - cross(w1, r1) +// J = [-I -r1_skew I r2_skew ] +// Identity used: +// w k % (rx i + ry j) = w * (-ry i + rx j) + +// Motor constraint +// Cdot = w2 - w1 +// J = [0 0 -1 0 0 1] +// K = invI1 + invI2 + +void b2RevoluteJointDef::Initialize(b2Body* b1, b2Body* b2, const b2Vec2& anchor) +{ + bodyA = b1; + bodyB = b2; + localAnchorA = bodyA->GetLocalPoint(anchor); + localAnchorB = bodyB->GetLocalPoint(anchor); + referenceAngle = bodyB->GetAngle() - bodyA->GetAngle(); +} + +b2RevoluteJoint::b2RevoluteJoint(const b2RevoluteJointDef* def) +: b2Joint(def) +{ + m_localAnchor1 = def->localAnchorA; + m_localAnchor2 = def->localAnchorB; + m_referenceAngle = def->referenceAngle; + + m_impulse.SetZero(); + m_motorImpulse = 0.0f; + + m_lowerAngle = def->lowerAngle; + m_upperAngle = def->upperAngle; + m_maxMotorTorque = def->maxMotorTorque; + m_motorSpeed = def->motorSpeed; + m_enableLimit = def->enableLimit; + m_enableMotor = def->enableMotor; + m_limitState = e_inactiveLimit; +} + +void b2RevoluteJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + if (m_enableMotor || m_enableLimit) + { + // You cannot create a rotation limit between bodies that + // both have fixed rotation. + b2Assert(b1->m_invI > 0.0f || b2->m_invI > 0.0f); + } + + // Compute the effective mass matrix. + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + // J = [-I -r1_skew I r2_skew] + // [ 0 -1 0 1] + // r_skew = [-ry; rx] + + // Matlab + // K = [ m1+r1y^2*i1+m2+r2y^2*i2, -r1y*i1*r1x-r2y*i2*r2x, -r1y*i1-r2y*i2] + // [ -r1y*i1*r1x-r2y*i2*r2x, m1+r1x^2*i1+m2+r2x^2*i2, r1x*i1+r2x*i2] + // [ -r1y*i1-r2y*i2, r1x*i1+r2x*i2, i1+i2] + + float32 m1 = b1->m_invMass, m2 = b2->m_invMass; + float32 i1 = b1->m_invI, i2 = b2->m_invI; + + m_mass.col1.x = m1 + m2 + r1.y * r1.y * i1 + r2.y * r2.y * i2; + m_mass.col2.x = -r1.y * r1.x * i1 - r2.y * r2.x * i2; + m_mass.col3.x = -r1.y * i1 - r2.y * i2; + m_mass.col1.y = m_mass.col2.x; + m_mass.col2.y = m1 + m2 + r1.x * r1.x * i1 + r2.x * r2.x * i2; + m_mass.col3.y = r1.x * i1 + r2.x * i2; + m_mass.col1.z = m_mass.col3.x; + m_mass.col2.z = m_mass.col3.y; + m_mass.col3.z = i1 + i2; + + m_motorMass = i1 + i2; + if (m_motorMass > 0.0f) + { + m_motorMass = 1.0f / m_motorMass; + } + + if (m_enableMotor == false) + { + m_motorImpulse = 0.0f; + } + + if (m_enableLimit) + { + float32 jointAngle = b2->m_sweep.a - b1->m_sweep.a - m_referenceAngle; + if (b2Abs(m_upperAngle - m_lowerAngle) < 2.0f * b2_angularSlop) + { + m_limitState = e_equalLimits; + } + else if (jointAngle <= m_lowerAngle) + { + if (m_limitState != e_atLowerLimit) + { + m_impulse.z = 0.0f; + } + m_limitState = e_atLowerLimit; + } + else if (jointAngle >= m_upperAngle) + { + if (m_limitState != e_atUpperLimit) + { + m_impulse.z = 0.0f; + } + m_limitState = e_atUpperLimit; + } + else + { + m_limitState = e_inactiveLimit; + m_impulse.z = 0.0f; + } + } + else + { + m_limitState = e_inactiveLimit; + } + + if (step.warmStarting) + { + // Scale impulses to support a variable time step. + m_impulse *= step.dtRatio; + m_motorImpulse *= step.dtRatio; + + b2Vec2 P(m_impulse.x, m_impulse.y); + + b1->m_linearVelocity -= m1 * P; + b1->m_angularVelocity -= i1 * (b2Cross(r1, P) + m_motorImpulse + m_impulse.z); + + b2->m_linearVelocity += m2 * P; + b2->m_angularVelocity += i2 * (b2Cross(r2, P) + m_motorImpulse + m_impulse.z); + } + else + { + m_impulse.SetZero(); + m_motorImpulse = 0.0f; + } +} + +void b2RevoluteJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + b2Vec2 v1 = b1->m_linearVelocity; + float32 w1 = b1->m_angularVelocity; + b2Vec2 v2 = b2->m_linearVelocity; + float32 w2 = b2->m_angularVelocity; + + float32 m1 = b1->m_invMass, m2 = b2->m_invMass; + float32 i1 = b1->m_invI, i2 = b2->m_invI; + + // Solve motor constraint. + if (m_enableMotor && m_limitState != e_equalLimits) + { + float32 Cdot = w2 - w1 - m_motorSpeed; + float32 impulse = m_motorMass * (-Cdot); + float32 oldImpulse = m_motorImpulse; + float32 maxImpulse = step.dt * m_maxMotorTorque; + m_motorImpulse = b2Clamp(m_motorImpulse + impulse, -maxImpulse, maxImpulse); + impulse = m_motorImpulse - oldImpulse; + + w1 -= i1 * impulse; + w2 += i2 * impulse; + } + + // Solve limit constraint. + if (m_enableLimit && m_limitState != e_inactiveLimit) + { + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + // Solve point-to-point constraint + b2Vec2 Cdot1 = v2 + b2Cross(w2, r2) - v1 - b2Cross(w1, r1); + float32 Cdot2 = w2 - w1; + b2Vec3 Cdot(Cdot1.x, Cdot1.y, Cdot2); + + b2Vec3 impulse = m_mass.Solve33(-Cdot); + + if (m_limitState == e_equalLimits) + { + m_impulse += impulse; + } + else if (m_limitState == e_atLowerLimit) + { + float32 newImpulse = m_impulse.z + impulse.z; + if (newImpulse < 0.0f) + { + b2Vec2 reduced = m_mass.Solve22(-Cdot1); + impulse.x = reduced.x; + impulse.y = reduced.y; + impulse.z = -m_impulse.z; + m_impulse.x += reduced.x; + m_impulse.y += reduced.y; + m_impulse.z = 0.0f; + } + } + else if (m_limitState == e_atUpperLimit) + { + float32 newImpulse = m_impulse.z + impulse.z; + if (newImpulse > 0.0f) + { + b2Vec2 reduced = m_mass.Solve22(-Cdot1); + impulse.x = reduced.x; + impulse.y = reduced.y; + impulse.z = -m_impulse.z; + m_impulse.x += reduced.x; + m_impulse.y += reduced.y; + m_impulse.z = 0.0f; + } + } + + b2Vec2 P(impulse.x, impulse.y); + + v1 -= m1 * P; + w1 -= i1 * (b2Cross(r1, P) + impulse.z); + + v2 += m2 * P; + w2 += i2 * (b2Cross(r2, P) + impulse.z); + } + else + { + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + // Solve point-to-point constraint + b2Vec2 Cdot = v2 + b2Cross(w2, r2) - v1 - b2Cross(w1, r1); + b2Vec2 impulse = m_mass.Solve22(-Cdot); + + m_impulse.x += impulse.x; + m_impulse.y += impulse.y; + + v1 -= m1 * impulse; + w1 -= i1 * b2Cross(r1, impulse); + + v2 += m2 * impulse; + w2 += i2 * b2Cross(r2, impulse); + } + + b1->m_linearVelocity = v1; + b1->m_angularVelocity = w1; + b2->m_linearVelocity = v2; + b2->m_angularVelocity = w2; +} + +bool b2RevoluteJoint::SolvePositionConstraints(float32 baumgarte) +{ + // TODO_ERIN block solve with limit. + + B2_NOT_USED(baumgarte); + + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + + float32 angularError = 0.0f; + float32 positionError = 0.0f; + + // Solve angular limit constraint. + if (m_enableLimit && m_limitState != e_inactiveLimit) + { + float32 angle = b2->m_sweep.a - b1->m_sweep.a - m_referenceAngle; + float32 limitImpulse = 0.0f; + + if (m_limitState == e_equalLimits) + { + // Prevent large angular corrections + float32 C = b2Clamp(angle - m_lowerAngle, -b2_maxAngularCorrection, b2_maxAngularCorrection); + limitImpulse = -m_motorMass * C; + angularError = b2Abs(C); + } + else if (m_limitState == e_atLowerLimit) + { + float32 C = angle - m_lowerAngle; + angularError = -C; + + // Prevent large angular corrections and allow some slop. + C = b2Clamp(C + b2_angularSlop, -b2_maxAngularCorrection, 0.0f); + limitImpulse = -m_motorMass * C; + } + else if (m_limitState == e_atUpperLimit) + { + float32 C = angle - m_upperAngle; + angularError = C; + + // Prevent large angular corrections and allow some slop. + C = b2Clamp(C - b2_angularSlop, 0.0f, b2_maxAngularCorrection); + limitImpulse = -m_motorMass * C; + } + + b1->m_sweep.a -= b1->m_invI * limitImpulse; + b2->m_sweep.a += b2->m_invI * limitImpulse; + + b1->SynchronizeTransform(); + b2->SynchronizeTransform(); + } + + // Solve point-to-point constraint. + { + b2Vec2 r1 = b2Mul(b1->GetTransform().R, m_localAnchor1 - b1->GetLocalCenter()); + b2Vec2 r2 = b2Mul(b2->GetTransform().R, m_localAnchor2 - b2->GetLocalCenter()); + + b2Vec2 C = b2->m_sweep.c + r2 - b1->m_sweep.c - r1; + positionError = C.Length(); + + float32 invMass1 = b1->m_invMass, invMass2 = b2->m_invMass; + float32 invI1 = b1->m_invI, invI2 = b2->m_invI; + + // Handle large detachment. + const float32 k_allowedStretch = 10.0f * b2_linearSlop; + if (C.LengthSquared() > k_allowedStretch * k_allowedStretch) + { + // Use a particle solution (no rotation). + b2Vec2 u = C; u.Normalize(); + float32 m = invMass1 + invMass2; + if (m > 0.0f) + { + m = 1.0f / m; + } + b2Vec2 impulse = m * (-C); + const float32 k_beta = 0.5f; + b1->m_sweep.c -= k_beta * invMass1 * impulse; + b2->m_sweep.c += k_beta * invMass2 * impulse; + + C = b2->m_sweep.c + r2 - b1->m_sweep.c - r1; + } + + b2Mat22 K1; + K1.col1.x = invMass1 + invMass2; K1.col2.x = 0.0f; + K1.col1.y = 0.0f; K1.col2.y = invMass1 + invMass2; + + b2Mat22 K2; + K2.col1.x = invI1 * r1.y * r1.y; K2.col2.x = -invI1 * r1.x * r1.y; + K2.col1.y = -invI1 * r1.x * r1.y; K2.col2.y = invI1 * r1.x * r1.x; + + b2Mat22 K3; + K3.col1.x = invI2 * r2.y * r2.y; K3.col2.x = -invI2 * r2.x * r2.y; + K3.col1.y = -invI2 * r2.x * r2.y; K3.col2.y = invI2 * r2.x * r2.x; + + b2Mat22 K = K1 + K2 + K3; + b2Vec2 impulse = K.Solve(-C); + + b1->m_sweep.c -= b1->m_invMass * impulse; + b1->m_sweep.a -= b1->m_invI * b2Cross(r1, impulse); + + b2->m_sweep.c += b2->m_invMass * impulse; + b2->m_sweep.a += b2->m_invI * b2Cross(r2, impulse); + + b1->SynchronizeTransform(); + b2->SynchronizeTransform(); + } + + return positionError <= b2_linearSlop && angularError <= b2_angularSlop; +} + +b2Vec2 b2RevoluteJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchor1); +} + +b2Vec2 b2RevoluteJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchor2); +} + +b2Vec2 b2RevoluteJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 P(m_impulse.x, m_impulse.y); + return inv_dt * P; +} + +float32 b2RevoluteJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_impulse.z; +} + +float32 b2RevoluteJoint::GetJointAngle() const +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + return b2->m_sweep.a - b1->m_sweep.a - m_referenceAngle; +} + +float32 b2RevoluteJoint::GetJointSpeed() const +{ + b2Body* b1 = m_bodyA; + b2Body* b2 = m_bodyB; + return b2->m_angularVelocity - b1->m_angularVelocity; +} + +bool b2RevoluteJoint::IsMotorEnabled() const +{ + return m_enableMotor; +} + +void b2RevoluteJoint::EnableMotor(bool flag) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableMotor = flag; +} + +float32 b2RevoluteJoint::GetMotorTorque() const +{ + return m_motorImpulse; +} + +void b2RevoluteJoint::SetMotorSpeed(float32 speed) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_motorSpeed = speed; +} + +void b2RevoluteJoint::SetMaxMotorTorque(float32 torque) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_maxMotorTorque = torque; +} + +bool b2RevoluteJoint::IsLimitEnabled() const +{ + return m_enableLimit; +} + +void b2RevoluteJoint::EnableLimit(bool flag) +{ + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_enableLimit = flag; +} + +float32 b2RevoluteJoint::GetLowerLimit() const +{ + return m_lowerAngle; +} + +float32 b2RevoluteJoint::GetUpperLimit() const +{ + return m_upperAngle; +} + +void b2RevoluteJoint::SetLimits(float32 lower, float32 upper) +{ + b2Assert(lower <= upper); + m_bodyA->SetAwake(true); + m_bodyB->SetAwake(true); + m_lowerAngle = lower; + m_upperAngle = upper; +} diff --git a/uppsrc/plugin/box2d/b2RevoluteJoint.h b/uppsrc/plugin/box2d/b2RevoluteJoint.h new file mode 100644 index 000000000..e212f6bad --- /dev/null +++ b/uppsrc/plugin/box2d/b2RevoluteJoint.h @@ -0,0 +1,174 @@ +/* +* Copyright (c) 2006-2007 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_REVOLUTE_JOINT_H +#define B2_REVOLUTE_JOINT_H + +#include "b2Joint.h" + +/// Revolute joint definition. This requires defining an +/// anchor point where the bodies are joined. The definition +/// uses local anchor points so that the initial configuration +/// can violate the constraint slightly. You also need to +/// specify the initial relative angle for joint limits. This +/// helps when saving and loading a game. +/// The local anchor points are measured from the body's origin +/// rather than the center of mass because: +/// 1. you might not know where the center of mass will be. +/// 2. if you add/remove shapes from a body and recompute the mass, +/// the joints will be broken. +struct b2RevoluteJointDef : public b2JointDef +{ + b2RevoluteJointDef() + { + type = e_revoluteJoint; + localAnchorA.Set(0.0f, 0.0f); + localAnchorB.Set(0.0f, 0.0f); + referenceAngle = 0.0f; + lowerAngle = 0.0f; + upperAngle = 0.0f; + maxMotorTorque = 0.0f; + motorSpeed = 0.0f; + enableLimit = false; + enableMotor = false; + } + + /// Initialize the bodies, anchors, and reference angle using a world + /// anchor point. + void Initialize(b2Body* bodyA, b2Body* bodyB, const b2Vec2& anchor); + + /// The local anchor point relative to body1's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to body2's origin. + b2Vec2 localAnchorB; + + /// The body2 angle minus body1 angle in the reference state (radians). + float32 referenceAngle; + + /// A flag to enable joint limits. + bool enableLimit; + + /// The lower angle for the joint limit (radians). + float32 lowerAngle; + + /// The upper angle for the joint limit (radians). + float32 upperAngle; + + /// A flag to enable the joint motor. + bool enableMotor; + + /// The desired motor speed. Usually in radians per second. + float32 motorSpeed; + + /// The maximum motor torque used to achieve the desired motor speed. + /// Usually in N-m. + float32 maxMotorTorque; +}; + +/// A revolute joint constrains two bodies to share a common point while they +/// are free to rotate about the point. The relative rotation about the shared +/// point is the joint angle. You can limit the relative rotation with +/// a joint limit that specifies a lower and upper angle. You can use a motor +/// to drive the relative rotation about the shared point. A maximum motor torque +/// is provided so that infinite forces are not generated. +class b2RevoluteJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const; + b2Vec2 GetAnchorB() const; + + b2Vec2 GetReactionForce(float32 inv_dt) const; + float32 GetReactionTorque(float32 inv_dt) const; + + /// Get the current joint angle in radians. + float32 GetJointAngle() const; + + /// Get the current joint angle speed in radians per second. + float32 GetJointSpeed() const; + + /// Is the joint limit enabled? + bool IsLimitEnabled() const; + + /// Enable/disable the joint limit. + void EnableLimit(bool flag); + + /// Get the lower joint limit in radians. + float32 GetLowerLimit() const; + + /// Get the upper joint limit in radians. + float32 GetUpperLimit() const; + + /// Set the joint limits in radians. + void SetLimits(float32 lower, float32 upper); + + /// Is the joint motor enabled? + bool IsMotorEnabled() const; + + /// Enable/disable the joint motor. + void EnableMotor(bool flag); + + /// Set the motor speed in radians per second. + void SetMotorSpeed(float32 speed); + + /// Get the motor speed in radians per second. + float32 GetMotorSpeed() const; + + /// Set the maximum motor torque, usually in N-m. + void SetMaxMotorTorque(float32 torque); + + /// Get the current motor torque, usually in N-m. + float32 GetMotorTorque() const; + +protected: + + friend class b2Joint; + friend class b2GearJoint; + + b2RevoluteJoint(const b2RevoluteJointDef* def); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + + bool SolvePositionConstraints(float32 baumgarte); + + b2Vec2 m_localAnchor1; // relative + b2Vec2 m_localAnchor2; + b2Vec3 m_impulse; + float32 m_motorImpulse; + + b2Mat33 m_mass; // effective mass for point-to-point constraint. + float32 m_motorMass; // effective mass for motor/limit angular constraint. + + bool m_enableMotor; + float32 m_maxMotorTorque; + float32 m_motorSpeed; + + bool m_enableLimit; + float32 m_referenceAngle; + float32 m_lowerAngle; + float32 m_upperAngle; + b2LimitState m_limitState; +}; + +inline float32 b2RevoluteJoint::GetMotorSpeed() const +{ + return m_motorSpeed; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2Settings.cpp b/uppsrc/plugin/box2d/b2Settings.cpp new file mode 100644 index 000000000..7ca3e17a0 --- /dev/null +++ b/uppsrc/plugin/box2d/b2Settings.cpp @@ -0,0 +1,33 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Settings.h" +#include + +b2Version b2_version = {2, 1, 2}; + +// Memory allocators. Modify these to use your own allocator. +void* b2Alloc(int32 size) +{ + return malloc(size); +} + +void b2Free(void* mem) +{ + free(mem); +} diff --git a/uppsrc/plugin/box2d/b2Settings.h b/uppsrc/plugin/box2d/b2Settings.h new file mode 100644 index 000000000..34875b14c --- /dev/null +++ b/uppsrc/plugin/box2d/b2Settings.h @@ -0,0 +1,151 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_SETTINGS_H +#define B2_SETTINGS_H + +#include +#include + +#define B2_NOT_USED(x) ((void)(x)) +#define b2Assert(A) assert(A) + +typedef signed char int8; +typedef signed short int16; +typedef signed int int32; +typedef unsigned char uint8; +typedef unsigned short uint16; +typedef unsigned int uint32; +typedef float float32; + +#define b2_maxFloat FLT_MAX +#define b2_epsilon FLT_EPSILON +#define b2_pi 3.14159265359f + +/// @file +/// Global tuning constants based on meters-kilograms-seconds (MKS) units. +/// + +// Collision + +/// The maximum number of contact points between two convex shapes. +#define b2_maxManifoldPoints 2 + +/// The maximum number of vertices on a convex polygon. +#define b2_maxPolygonVertices 8 + +/// This is used to fatten AABBs in the dynamic tree. This allows proxies +/// to move by a small amount without triggering a tree adjustment. +/// This is in meters. +#define b2_aabbExtension 0.1f + +/// This is used to fatten AABBs in the dynamic tree. This is used to predict +/// the future position based on the current displacement. +/// This is a dimensionless multiplier. +#define b2_aabbMultiplier 2.0f + +/// A small length used as a collision and constraint tolerance. Usually it is +/// chosen to be numerically significant, but visually insignificant. +#define b2_linearSlop 0.005f + +/// A small angle used as a collision and constraint tolerance. Usually it is +/// chosen to be numerically significant, but visually insignificant. +#define b2_angularSlop (2.0f / 180.0f * b2_pi) + +/// The radius of the polygon/edge shape skin. This should not be modified. Making +/// this smaller means polygons will have an insufficient buffer for continuous collision. +/// Making it larger may create artifacts for vertex collision. +#define b2_polygonRadius (2.0f * b2_linearSlop) + + +// Dynamics + +/// Maximum number of contacts to be handled to solve a TOI impact. +#define b2_maxTOIContacts 32 + +/// A velocity threshold for elastic collisions. Any collision with a relative linear +/// velocity below this threshold will be treated as inelastic. +#define b2_velocityThreshold 1.0f + +/// The maximum linear position correction used when solving constraints. This helps to +/// prevent overshoot. +#define b2_maxLinearCorrection 0.2f + +/// The maximum angular position correction used when solving constraints. This helps to +/// prevent overshoot. +#define b2_maxAngularCorrection (8.0f / 180.0f * b2_pi) + +/// The maximum linear velocity of a body. This limit is very large and is used +/// to prevent numerical problems. You shouldn't need to adjust this. +#define b2_maxTranslation 2.0f +#define b2_maxTranslationSquared (b2_maxTranslation * b2_maxTranslation) + +/// The maximum angular velocity of a body. This limit is very large and is used +/// to prevent numerical problems. You shouldn't need to adjust this. +#define b2_maxRotation (0.5f * b2_pi) +#define b2_maxRotationSquared (b2_maxRotation * b2_maxRotation) + +/// This scale factor controls how fast overlap is resolved. Ideally this would be 1 so +/// that overlap is removed in one time step. However using values close to 1 often lead +/// to overshoot. +#define b2_contactBaumgarte 0.2f + +// Sleep + +/// The time that a body must be still before it will go to sleep. +#define b2_timeToSleep 0.5f + +/// A body cannot sleep if its linear velocity is above this tolerance. +#define b2_linearSleepTolerance 0.01f + +/// A body cannot sleep if its angular velocity is above this tolerance. +#define b2_angularSleepTolerance (2.0f / 180.0f * b2_pi) + +// Memory Allocation + +/// Implement this function to use your own memory allocator. +void* b2Alloc(int32 size); + +/// If you implement b2Alloc, you should also implement this function. +void b2Free(void* mem); + +/// Version numbering scheme. +/// See http://en.wikipedia.org/wiki/Software_versioning +struct b2Version +{ + int32 major; ///< significant changes + int32 minor; ///< incremental changes + int32 revision; ///< bug fixes +}; + +/// Current version. +extern b2Version b2_version; + +/// Friction mixing law. Feel free to customize this. +inline float32 b2MixFriction(float32 friction1, float32 friction2) +{ + return sqrtf(friction1 * friction2); +} + +/// Restitution mixing law. Feel free to customize this. +inline float32 b2MixRestitution(float32 restitution1, float32 restitution2) +{ + return restitution1 > restitution2 ? restitution1 : restitution2; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2Shape.h b/uppsrc/plugin/box2d/b2Shape.h new file mode 100644 index 000000000..b0f8ee01b --- /dev/null +++ b/uppsrc/plugin/box2d/b2Shape.h @@ -0,0 +1,95 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_SHAPE_H +#define B2_SHAPE_H + +#include "b2BlockAllocator.h" +#include "b2Math.h" +#include "b2Collision.h" + +/// This holds the mass data computed for a shape. +struct b2MassData +{ + /// The mass of the shape, usually in kilograms. + float32 mass; + + /// The position of the shape's centroid relative to the shape's origin. + b2Vec2 center; + + /// The rotational inertia of the shape about the local origin. + float32 I; +}; + +/// A shape is used for collision detection. You can create a shape however you like. +/// Shapes used for simulation in b2World are created automatically when a b2Fixture +/// is created. +class b2Shape +{ +public: + + enum Type + { + e_unknown= -1, + e_circle = 0, + e_polygon = 1, + e_typeCount = 2, + }; + + b2Shape() { m_type = e_unknown; } + virtual ~b2Shape() {} + + /// Clone the concrete shape using the provided allocator. + virtual b2Shape* Clone(b2BlockAllocator* allocator) const = 0; + + /// Get the type of this shape. You can use this to down cast to the concrete shape. + /// @return the shape type. + Type GetType() const; + + /// Test a point for containment in this shape. This only works for convex shapes. + /// @param xf the shape world transform. + /// @param p a point in world coordinates. + virtual bool TestPoint(const b2Transform& xf, const b2Vec2& p) const = 0; + + /// Cast a ray against this shape. + /// @param output the ray-cast results. + /// @param input the ray-cast input parameters. + /// @param transform the transform to be applied to the shape. + virtual bool RayCast(b2RayCastOutput* output, const b2RayCastInput& input, const b2Transform& transform) const = 0; + + /// Given a transform, compute the associated axis aligned bounding box for this shape. + /// @param aabb returns the axis aligned box. + /// @param xf the world transform of the shape. + virtual void ComputeAABB(b2AABB* aabb, const b2Transform& xf) const = 0; + + /// Compute the mass properties of this shape using its dimensions and density. + /// The inertia tensor is computed about the local origin. + /// @param massData returns the mass data for this shape. + /// @param density the density in kilograms per meter squared. + virtual void ComputeMass(b2MassData* massData, float32 density) const = 0; + + Type m_type; + float32 m_radius; +}; + +inline b2Shape::Type b2Shape::GetType() const +{ + return m_type; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2StackAllocator.cpp b/uppsrc/plugin/box2d/b2StackAllocator.cpp new file mode 100644 index 000000000..034e2255d --- /dev/null +++ b/uppsrc/plugin/box2d/b2StackAllocator.cpp @@ -0,0 +1,83 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2StackAllocator.h" +#include "b2Math.h" + +b2StackAllocator::b2StackAllocator() +{ + m_index = 0; + m_allocation = 0; + m_maxAllocation = 0; + m_entryCount = 0; +} + +b2StackAllocator::~b2StackAllocator() +{ + b2Assert(m_index == 0); + b2Assert(m_entryCount == 0); +} + +void* b2StackAllocator::Allocate(int32 size) +{ + b2Assert(m_entryCount < b2_maxStackEntries); + + b2StackEntry* entry = m_entries + m_entryCount; + entry->size = size; + if (m_index + size > b2_stackSize) + { + entry->data = (char*)b2Alloc(size); + entry->usedMalloc = true; + } + else + { + entry->data = m_data + m_index; + entry->usedMalloc = false; + m_index += size; + } + + m_allocation += size; + m_maxAllocation = b2Max(m_maxAllocation, m_allocation); + ++m_entryCount; + + return entry->data; +} + +void b2StackAllocator::Free(void* p) +{ + b2Assert(m_entryCount > 0); + b2StackEntry* entry = m_entries + m_entryCount - 1; + b2Assert(p == entry->data); + if (entry->usedMalloc) + { + b2Free(p); + } + else + { + m_index -= entry->size; + } + m_allocation -= entry->size; + --m_entryCount; + + p = NULL; +} + +int32 b2StackAllocator::GetMaxAllocation() const +{ + return m_maxAllocation; +} diff --git a/uppsrc/plugin/box2d/b2StackAllocator.h b/uppsrc/plugin/box2d/b2StackAllocator.h new file mode 100644 index 000000000..a6a557acd --- /dev/null +++ b/uppsrc/plugin/box2d/b2StackAllocator.h @@ -0,0 +1,60 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_STACK_ALLOCATOR_H +#define B2_STACK_ALLOCATOR_H + +#include "b2Settings.h" + +const int32 b2_stackSize = 100 * 1024; // 100k +const int32 b2_maxStackEntries = 32; + +struct b2StackEntry +{ + char* data; + int32 size; + bool usedMalloc; +}; + +// This is a stack allocator used for fast per step allocations. +// You must nest allocate/free pairs. The code will assert +// if you try to interleave multiple allocate/free pairs. +class b2StackAllocator +{ +public: + b2StackAllocator(); + ~b2StackAllocator(); + + void* Allocate(int32 size); + void Free(void* p); + + int32 GetMaxAllocation() const; + +private: + + char m_data[b2_stackSize]; + int32 m_index; + + int32 m_allocation; + int32 m_maxAllocation; + + b2StackEntry m_entries[b2_maxStackEntries]; + int32 m_entryCount; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2TOISolver.cpp b/uppsrc/plugin/box2d/b2TOISolver.cpp new file mode 100644 index 000000000..6541d8b98 --- /dev/null +++ b/uppsrc/plugin/box2d/b2TOISolver.cpp @@ -0,0 +1,231 @@ +/* +* Copyright (c) 2006-2010 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2TOISolver.h" +#include "b2Contact.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2StackAllocator.h" + +struct b2TOIConstraint +{ + b2Vec2 localPoints[b2_maxManifoldPoints]; + b2Vec2 localNormal; + b2Vec2 localPoint; + b2Manifold::Type type; + float32 radius; + int32 pointCount; + b2Body* bodyA; + b2Body* bodyB; +}; + +b2TOISolver::b2TOISolver(b2StackAllocator* allocator) +{ + m_allocator = allocator; + m_constraints = NULL; + m_count = NULL; + m_toiBody = NULL; +} + +b2TOISolver::~b2TOISolver() +{ + Clear(); +} + +void b2TOISolver::Clear() +{ + if (m_allocator && m_constraints) + { + m_allocator->Free(m_constraints); + m_constraints = NULL; + } +} + +void b2TOISolver::Initialize(b2Contact** contacts, int32 count, b2Body* toiBody) +{ + Clear(); + + m_count = count; + m_toiBody = toiBody; + + m_constraints = (b2TOIConstraint*) m_allocator->Allocate(m_count * sizeof(b2TOIConstraint)); + + for (int32 i = 0; i < m_count; ++i) + { + b2Contact* contact = contacts[i]; + + b2Fixture* fixtureA = contact->GetFixtureA(); + b2Fixture* fixtureB = contact->GetFixtureB(); + b2Shape* shapeA = fixtureA->GetShape(); + b2Shape* shapeB = fixtureB->GetShape(); + float32 radiusA = shapeA->m_radius; + float32 radiusB = shapeB->m_radius; + b2Body* bodyA = fixtureA->GetBody(); + b2Body* bodyB = fixtureB->GetBody(); + b2Manifold* manifold = contact->GetManifold(); + + b2Assert(manifold->pointCount > 0); + + b2TOIConstraint* constraint = m_constraints + i; + constraint->bodyA = bodyA; + constraint->bodyB = bodyB; + constraint->localNormal = manifold->localNormal; + constraint->localPoint = manifold->localPoint; + constraint->type = manifold->type; + constraint->pointCount = manifold->pointCount; + constraint->radius = radiusA + radiusB; + + for (int32 j = 0; j < constraint->pointCount; ++j) + { + b2ManifoldPoint* cp = manifold->points + j; + constraint->localPoints[j] = cp->localPoint; + } + } +} + +struct b2TOISolverManifold +{ + void Initialize(b2TOIConstraint* cc, int32 index) + { + b2Assert(cc->pointCount > 0); + + switch (cc->type) + { + case b2Manifold::e_circles: + { + b2Vec2 pointA = cc->bodyA->GetWorldPoint(cc->localPoint); + b2Vec2 pointB = cc->bodyB->GetWorldPoint(cc->localPoints[0]); + if (b2DistanceSquared(pointA, pointB) > b2_epsilon * b2_epsilon) + { + normal = pointB - pointA; + normal.Normalize(); + } + else + { + normal.Set(1.0f, 0.0f); + } + + point = 0.5f * (pointA + pointB); + separation = b2Dot(pointB - pointA, normal) - cc->radius; + } + break; + + case b2Manifold::e_faceA: + { + normal = cc->bodyA->GetWorldVector(cc->localNormal); + b2Vec2 planePoint = cc->bodyA->GetWorldPoint(cc->localPoint); + + b2Vec2 clipPoint = cc->bodyB->GetWorldPoint(cc->localPoints[index]); + separation = b2Dot(clipPoint - planePoint, normal) - cc->radius; + point = clipPoint; + } + break; + + case b2Manifold::e_faceB: + { + normal = cc->bodyB->GetWorldVector(cc->localNormal); + b2Vec2 planePoint = cc->bodyB->GetWorldPoint(cc->localPoint); + + b2Vec2 clipPoint = cc->bodyA->GetWorldPoint(cc->localPoints[index]); + separation = b2Dot(clipPoint - planePoint, normal) - cc->radius; + point = clipPoint; + + // Ensure normal points from A to B + normal = -normal; + } + break; + } + } + + b2Vec2 normal; + b2Vec2 point; + float32 separation; +}; + +// Push out the toi body to provide clearance for further simulation. +bool b2TOISolver::Solve(float32 baumgarte) +{ + float32 minSeparation = 0.0f; + + for (int32 i = 0; i < m_count; ++i) + { + b2TOIConstraint* c = m_constraints + i; + b2Body* bodyA = c->bodyA; + b2Body* bodyB = c->bodyB; + + float32 massA = bodyA->m_mass; + float32 massB = bodyB->m_mass; + + // Only the TOI body should move. + if (bodyA == m_toiBody) + { + massB = 0.0f; + } + else + { + massA = 0.0f; + } + + float32 invMassA = massA * bodyA->m_invMass; + float32 invIA = massA * bodyA->m_invI; + float32 invMassB = massB * bodyB->m_invMass; + float32 invIB = massB * bodyB->m_invI; + + // Solve normal constraints + for (int32 j = 0; j < c->pointCount; ++j) + { + b2TOISolverManifold psm; + psm.Initialize(c, j); + b2Vec2 normal = psm.normal; + + b2Vec2 point = psm.point; + float32 separation = psm.separation; + + b2Vec2 rA = point - bodyA->m_sweep.c; + b2Vec2 rB = point - bodyB->m_sweep.c; + + // Track max constraint error. + minSeparation = b2Min(minSeparation, separation); + + // Prevent large corrections and allow slop. + float32 C = b2Clamp(baumgarte * (separation + b2_linearSlop), -b2_maxLinearCorrection, 0.0f); + + // Compute the effective mass. + float32 rnA = b2Cross(rA, normal); + float32 rnB = b2Cross(rB, normal); + float32 K = invMassA + invMassB + invIA * rnA * rnA + invIB * rnB * rnB; + + // Compute normal impulse + float32 impulse = K > 0.0f ? - C / K : 0.0f; + + b2Vec2 P = impulse * normal; + + bodyA->m_sweep.c -= invMassA * P; + bodyA->m_sweep.a -= invIA * b2Cross(rA, P); + bodyA->SynchronizeTransform(); + + bodyB->m_sweep.c += invMassB * P; + bodyB->m_sweep.a += invIB * b2Cross(rB, P); + bodyB->SynchronizeTransform(); + } + } + + // We can't expect minSpeparation >= -b2_linearSlop because we don't + // push the separation above -b2_linearSlop. + return minSeparation >= -1.5f * b2_linearSlop; +} diff --git a/uppsrc/plugin/box2d/b2TOISolver.h b/uppsrc/plugin/box2d/b2TOISolver.h new file mode 100644 index 000000000..aca3a7f2b --- /dev/null +++ b/uppsrc/plugin/box2d/b2TOISolver.h @@ -0,0 +1,51 @@ +/* +* Copyright (c) 2006-2010 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_TOI_SOLVER_H +#define B2_TOI_SOLVER_H + +#include "b2Math.h" + +class b2Contact; +class b2Body; +struct b2TOIConstraint; +class b2StackAllocator; + +/// This is a pure position solver for a single movable body in contact with +/// multiple non-moving bodies. +class b2TOISolver +{ +public: + b2TOISolver(b2StackAllocator* allocator); + ~b2TOISolver(); + + void Initialize(b2Contact** contacts, int32 contactCount, b2Body* toiBody); + void Clear(); + + // Perform one solver iteration. Returns true if converged. + bool Solve(float32 baumgarte); + +private: + + b2TOIConstraint* m_constraints; + int32 m_count; + b2Body* m_toiBody; + b2StackAllocator* m_allocator; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2TimeOfImpact.cpp b/uppsrc/plugin/box2d/b2TimeOfImpact.cpp new file mode 100644 index 000000000..9e272dfe1 --- /dev/null +++ b/uppsrc/plugin/box2d/b2TimeOfImpact.cpp @@ -0,0 +1,483 @@ +/* +* Copyright (c) 2007-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2Collision.h" +#include "b2Distance.h" +#include "b2TimeOfImpact.h" +#include "b2CircleShape.h" +#include "b2PolygonShape.h" + +#include + +int32 b2_toiCalls, b2_toiIters, b2_toiMaxIters; +int32 b2_toiRootIters, b2_toiMaxRootIters; + +int32 b2_toiMaxOptIters; + +struct b2SeparationFunction +{ + enum Type + { + e_points, + e_faceA, + e_faceB + }; + + // TODO_ERIN might not need to return the separation + + float32 Initialize(const b2SimplexCache* cache, + const b2DistanceProxy* proxyA, const b2Sweep& sweepA, + const b2DistanceProxy* proxyB, const b2Sweep& sweepB) + { + m_proxyA = proxyA; + m_proxyB = proxyB; + int32 count = cache->count; + b2Assert(0 < count && count < 3); + + m_sweepA = sweepA; + m_sweepB = sweepB; + + b2Transform xfA, xfB; + m_sweepA.GetTransform(&xfA, 0.0f); + m_sweepB.GetTransform(&xfB, 0.0f); + + if (count == 1) + { + m_type = e_points; + b2Vec2 localPointA = m_proxyA->GetVertex(cache->indexA[0]); + b2Vec2 localPointB = m_proxyB->GetVertex(cache->indexB[0]); + b2Vec2 pointA = b2Mul(xfA, localPointA); + b2Vec2 pointB = b2Mul(xfB, localPointB); + m_axis = pointB - pointA; + float32 s = m_axis.Normalize(); + return s; + } + else if (cache->indexA[0] == cache->indexA[1]) + { + // Two points on B and one on A. + m_type = e_faceB; + b2Vec2 localPointB1 = proxyB->GetVertex(cache->indexB[0]); + b2Vec2 localPointB2 = proxyB->GetVertex(cache->indexB[1]); + + m_axis = b2Cross(localPointB2 - localPointB1, 1.0f); + m_axis.Normalize(); + b2Vec2 normal = b2Mul(xfB.R, m_axis); + + m_localPoint = 0.5f * (localPointB1 + localPointB2); + b2Vec2 pointB = b2Mul(xfB, m_localPoint); + + b2Vec2 localPointA = proxyA->GetVertex(cache->indexA[0]); + b2Vec2 pointA = b2Mul(xfA, localPointA); + + float32 s = b2Dot(pointA - pointB, normal); + if (s < 0.0f) + { + m_axis = -m_axis; + s = -s; + } + return s; + } + else + { + // Two points on A and one or two points on B. + m_type = e_faceA; + b2Vec2 localPointA1 = m_proxyA->GetVertex(cache->indexA[0]); + b2Vec2 localPointA2 = m_proxyA->GetVertex(cache->indexA[1]); + + m_axis = b2Cross(localPointA2 - localPointA1, 1.0f); + m_axis.Normalize(); + b2Vec2 normal = b2Mul(xfA.R, m_axis); + + m_localPoint = 0.5f * (localPointA1 + localPointA2); + b2Vec2 pointA = b2Mul(xfA, m_localPoint); + + b2Vec2 localPointB = m_proxyB->GetVertex(cache->indexB[0]); + b2Vec2 pointB = b2Mul(xfB, localPointB); + + float32 s = b2Dot(pointB - pointA, normal); + if (s < 0.0f) + { + m_axis = -m_axis; + s = -s; + } + return s; + } + } + + float32 FindMinSeparation(int32* indexA, int32* indexB, float32 t) const + { + b2Transform xfA, xfB; + m_sweepA.GetTransform(&xfA, t); + m_sweepB.GetTransform(&xfB, t); + + switch (m_type) + { + case e_points: + { + b2Vec2 axisA = b2MulT(xfA.R, m_axis); + b2Vec2 axisB = b2MulT(xfB.R, -m_axis); + + *indexA = m_proxyA->GetSupport(axisA); + *indexB = m_proxyB->GetSupport(axisB); + + b2Vec2 localPointA = m_proxyA->GetVertex(*indexA); + b2Vec2 localPointB = m_proxyB->GetVertex(*indexB); + + b2Vec2 pointA = b2Mul(xfA, localPointA); + b2Vec2 pointB = b2Mul(xfB, localPointB); + + float32 separation = b2Dot(pointB - pointA, m_axis); + return separation; + } + + case e_faceA: + { + b2Vec2 normal = b2Mul(xfA.R, m_axis); + b2Vec2 pointA = b2Mul(xfA, m_localPoint); + + b2Vec2 axisB = b2MulT(xfB.R, -normal); + + *indexA = -1; + *indexB = m_proxyB->GetSupport(axisB); + + b2Vec2 localPointB = m_proxyB->GetVertex(*indexB); + b2Vec2 pointB = b2Mul(xfB, localPointB); + + float32 separation = b2Dot(pointB - pointA, normal); + return separation; + } + + case e_faceB: + { + b2Vec2 normal = b2Mul(xfB.R, m_axis); + b2Vec2 pointB = b2Mul(xfB, m_localPoint); + + b2Vec2 axisA = b2MulT(xfA.R, -normal); + + *indexB = -1; + *indexA = m_proxyA->GetSupport(axisA); + + b2Vec2 localPointA = m_proxyA->GetVertex(*indexA); + b2Vec2 pointA = b2Mul(xfA, localPointA); + + float32 separation = b2Dot(pointA - pointB, normal); + return separation; + } + + default: + b2Assert(false); + *indexA = -1; + *indexB = -1; + return 0.0f; + } + } + + float32 Evaluate(int32 indexA, int32 indexB, float32 t) const + { + b2Transform xfA, xfB; + m_sweepA.GetTransform(&xfA, t); + m_sweepB.GetTransform(&xfB, t); + + switch (m_type) + { + case e_points: + { + b2Vec2 axisA = b2MulT(xfA.R, m_axis); + b2Vec2 axisB = b2MulT(xfB.R, -m_axis); + + b2Vec2 localPointA = m_proxyA->GetVertex(indexA); + b2Vec2 localPointB = m_proxyB->GetVertex(indexB); + + b2Vec2 pointA = b2Mul(xfA, localPointA); + b2Vec2 pointB = b2Mul(xfB, localPointB); + float32 separation = b2Dot(pointB - pointA, m_axis); + + return separation; + } + + case e_faceA: + { + b2Vec2 normal = b2Mul(xfA.R, m_axis); + b2Vec2 pointA = b2Mul(xfA, m_localPoint); + + b2Vec2 axisB = b2MulT(xfB.R, -normal); + + b2Vec2 localPointB = m_proxyB->GetVertex(indexB); + b2Vec2 pointB = b2Mul(xfB, localPointB); + + float32 separation = b2Dot(pointB - pointA, normal); + return separation; + } + + case e_faceB: + { + b2Vec2 normal = b2Mul(xfB.R, m_axis); + b2Vec2 pointB = b2Mul(xfB, m_localPoint); + + b2Vec2 axisA = b2MulT(xfA.R, -normal); + + b2Vec2 localPointA = m_proxyA->GetVertex(indexA); + b2Vec2 pointA = b2Mul(xfA, localPointA); + + float32 separation = b2Dot(pointA - pointB, normal); + return separation; + } + + default: + b2Assert(false); + return 0.0f; + } + } + + const b2DistanceProxy* m_proxyA; + const b2DistanceProxy* m_proxyB; + b2Sweep m_sweepA, m_sweepB; + Type m_type; + b2Vec2 m_localPoint; + b2Vec2 m_axis; +}; + +// CCD via the local separating axis method. This seeks progression +// by computing the largest time at which separation is maintained. +void b2TimeOfImpact(b2TOIOutput* output, const b2TOIInput* input) +{ + ++b2_toiCalls; + + output->state = b2TOIOutput::e_unknown; + output->t = input->tMax; + + const b2DistanceProxy* proxyA = &input->proxyA; + const b2DistanceProxy* proxyB = &input->proxyB; + + b2Sweep sweepA = input->sweepA; + b2Sweep sweepB = input->sweepB; + + // Large rotations can make the root finder fail, so we normalize the + // sweep angles. + sweepA.Normalize(); + sweepB.Normalize(); + + float32 tMax = input->tMax; + + float32 totalRadius = proxyA->m_radius + proxyB->m_radius; + float32 target = b2Max(b2_linearSlop, totalRadius - 3.0f * b2_linearSlop); + float32 tolerance = 0.25f * b2_linearSlop; + b2Assert(target > tolerance); + + float32 t1 = 0.0f; + const int32 k_maxIterations = 20; // TODO_ERIN b2Settings + int32 iter = 0; + + // Prepare input for distance query. + b2SimplexCache cache; + cache.count = 0; + b2DistanceInput distanceInput; + distanceInput.proxyA = input->proxyA; + distanceInput.proxyB = input->proxyB; + distanceInput.useRadii = false; + + // The outer loop progressively attempts to compute new separating axes. + // This loop terminates when an axis is repeated (no progress is made). + for(;;) + { + b2Transform xfA, xfB; + sweepA.GetTransform(&xfA, t1); + sweepB.GetTransform(&xfB, t1); + + // Get the distance between shapes. We can also use the results + // to get a separating axis. + distanceInput.transformA = xfA; + distanceInput.transformB = xfB; + b2DistanceOutput distanceOutput; + b2Distance(&distanceOutput, &cache, &distanceInput); + + // If the shapes are overlapped, we give up on continuous collision. + if (distanceOutput.distance <= 0.0f) + { + // Failure! + output->state = b2TOIOutput::e_overlapped; + output->t = 0.0f; + break; + } + + if (distanceOutput.distance < target + tolerance) + { + // Victory! + output->state = b2TOIOutput::e_touching; + output->t = t1; + break; + } + + // Initialize the separating axis. + b2SeparationFunction fcn; + fcn.Initialize(&cache, proxyA, sweepA, proxyB, sweepB); +#if 0 + // Dump the curve seen by the root finder + { + const int32 N = 100; + float32 dx = 1.0f / N; + float32 xs[N+1]; + float32 fs[N+1]; + + float32 x = 0.0f; + + for (int32 i = 0; i <= N; ++i) + { + sweepA.GetTransform(&xfA, x); + sweepB.GetTransform(&xfB, x); + float32 f = fcn.Evaluate(xfA, xfB) - target; + + printf("%g %g\n", x, f); + + xs[i] = x; + fs[i] = f; + + x += dx; + } + } +#endif + + // Compute the TOI on the separating axis. We do this by successively + // resolving the deepest point. This loop is bounded by the number of vertices. + bool done = false; + float32 t2 = tMax; + int32 pushBackIter = 0; + for (;;) + { + // Find the deepest point at t2. Store the witness point indices. + int32 indexA, indexB; + float32 s2 = fcn.FindMinSeparation(&indexA, &indexB, t2); + + // Is the final configuration separated? + if (s2 > target + tolerance) + { + // Victory! + output->state = b2TOIOutput::e_separated; + output->t = tMax; + done = true; + break; + } + + // Has the separation reached tolerance? + if (s2 > target - tolerance) + { + // Advance the sweeps + t1 = t2; + break; + } + + // Compute the initial separation of the witness points. + float32 s1 = fcn.Evaluate(indexA, indexB, t1); + + // Check for initial overlap. This might happen if the root finder + // runs out of iterations. + if (s1 < target - tolerance) + { + output->state = b2TOIOutput::e_failed; + output->t = t1; + done = true; + break; + } + + // Check for touching + if (s1 <= target + tolerance) + { + // Victory! t1 should hold the TOI (could be 0.0). + output->state = b2TOIOutput::e_touching; + output->t = t1; + done = true; + break; + } + + // Compute 1D root of: f(x) - target = 0 + int32 rootIterCount = 0; + float32 a1 = t1, a2 = t2; + for (;;) + { + // Use a mix of the secant rule and bisection. + float32 t; + if (rootIterCount & 1) + { + // Secant rule to improve convergence. + t = a1 + (target - s1) * (a2 - a1) / (s2 - s1); + } + else + { + // Bisection to guarantee progress. + t = 0.5f * (a1 + a2); + } + + float32 s = fcn.Evaluate(indexA, indexB, t); + + if (b2Abs(s - target) < tolerance) + { + // t2 holds a tentative value for t1 + t2 = t; + break; + } + + // Ensure we continue to bracket the root. + if (s > target) + { + a1 = t; + s1 = s; + } + else + { + a2 = t; + s2 = s; + } + + ++rootIterCount; + ++b2_toiRootIters; + + if (rootIterCount == 50) + { + break; + } + } + + b2_toiMaxRootIters = b2Max(b2_toiMaxRootIters, rootIterCount); + + ++pushBackIter; + + if (pushBackIter == b2_maxPolygonVertices) + { + break; + } + } + + ++iter; + ++b2_toiIters; + + if (done) + { + break; + } + + if (iter == k_maxIterations) + { + // Root finder got stuck. Semi-victory. + output->state = b2TOIOutput::e_failed; + output->t = t1; + break; + } + } + + b2_toiMaxIters = b2Max(b2_toiMaxIters, iter); +} diff --git a/uppsrc/plugin/box2d/b2TimeOfImpact.h b/uppsrc/plugin/box2d/b2TimeOfImpact.h new file mode 100644 index 000000000..5c1ca8d6c --- /dev/null +++ b/uppsrc/plugin/box2d/b2TimeOfImpact.h @@ -0,0 +1,59 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_TIME_OF_IMPACT_H +#define B2_TIME_OF_IMPACT_H + +#include "b2Math.h" +#include "b2Distance.h" +#include + +/// Input parameters for b2TimeOfImpact +struct b2TOIInput +{ + b2DistanceProxy proxyA; + b2DistanceProxy proxyB; + b2Sweep sweepA; + b2Sweep sweepB; + float32 tMax; // defines sweep interval [0, tMax] +}; + +// Output parameters for b2TimeOfImpact. +struct b2TOIOutput +{ + enum State + { + e_unknown, + e_failed, + e_overlapped, + e_touching, + e_separated + }; + + State state; + float32 t; +}; + +/// Compute the upper bound on time before two shapes penetrate. Time is represented as +/// a fraction between [0,tMax]. This uses a swept separating axis and may miss some intermediate, +/// non-tunneling collision. If you change the time interval, you should call this function +/// again. +/// Note: use b2Distance to compute the contact point and normal at the time of impact. +void b2TimeOfImpact(b2TOIOutput* output, const b2TOIInput* input); + +#endif diff --git a/uppsrc/plugin/box2d/b2TimeStep.h b/uppsrc/plugin/box2d/b2TimeStep.h new file mode 100644 index 000000000..5eddfc3c1 --- /dev/null +++ b/uppsrc/plugin/box2d/b2TimeStep.h @@ -0,0 +1,35 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_TIME_STEP_H +#define B2_TIME_STEP_H + +#include "b2Settings.h" + +/// This is an internal structure. +struct b2TimeStep +{ + float32 dt; // time step + float32 inv_dt; // inverse time step (0 if dt == 0). + float32 dtRatio; // dt * inv_dt0 + int32 velocityIterations; + int32 positionIterations; + bool warmStarting; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2WeldJoint.cpp b/uppsrc/plugin/box2d/b2WeldJoint.cpp new file mode 100644 index 000000000..551892deb --- /dev/null +++ b/uppsrc/plugin/box2d/b2WeldJoint.cpp @@ -0,0 +1,219 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2WeldJoint.h" +#include "b2Body.h" +#include "b2TimeStep.h" + +// Point-to-point constraint +// C = p2 - p1 +// Cdot = v2 - v1 +// = v2 + cross(w2, r2) - v1 - cross(w1, r1) +// J = [-I -r1_skew I r2_skew ] +// Identity used: +// w k % (rx i + ry j) = w * (-ry i + rx j) + +// Angle constraint +// C = angle2 - angle1 - referenceAngle +// Cdot = w2 - w1 +// J = [0 0 -1 0 0 1] +// K = invI1 + invI2 + +void b2WeldJointDef::Initialize(b2Body* bA, b2Body* bB, const b2Vec2& anchor) +{ + bodyA = bA; + bodyB = bB; + localAnchorA = bodyA->GetLocalPoint(anchor); + localAnchorB = bodyB->GetLocalPoint(anchor); + referenceAngle = bodyB->GetAngle() - bodyA->GetAngle(); +} + +b2WeldJoint::b2WeldJoint(const b2WeldJointDef* def) +: b2Joint(def) +{ + m_localAnchorA = def->localAnchorA; + m_localAnchorB = def->localAnchorB; + m_referenceAngle = def->referenceAngle; + + m_impulse.SetZero(); +} + +void b2WeldJoint::InitVelocityConstraints(const b2TimeStep& step) +{ + b2Body* bA = m_bodyA; + b2Body* bB = m_bodyB; + + // Compute the effective mass matrix. + b2Vec2 rA = b2Mul(bA->GetTransform().R, m_localAnchorA - bA->GetLocalCenter()); + b2Vec2 rB = b2Mul(bB->GetTransform().R, m_localAnchorB - bB->GetLocalCenter()); + + // J = [-I -r1_skew I r2_skew] + // [ 0 -1 0 1] + // r_skew = [-ry; rx] + + // Matlab + // K = [ mA+r1y^2*iA+mB+r2y^2*iB, -r1y*iA*r1x-r2y*iB*r2x, -r1y*iA-r2y*iB] + // [ -r1y*iA*r1x-r2y*iB*r2x, mA+r1x^2*iA+mB+r2x^2*iB, r1x*iA+r2x*iB] + // [ -r1y*iA-r2y*iB, r1x*iA+r2x*iB, iA+iB] + + float32 mA = bA->m_invMass, mB = bB->m_invMass; + float32 iA = bA->m_invI, iB = bB->m_invI; + + m_mass.col1.x = mA + mB + rA.y * rA.y * iA + rB.y * rB.y * iB; + m_mass.col2.x = -rA.y * rA.x * iA - rB.y * rB.x * iB; + m_mass.col3.x = -rA.y * iA - rB.y * iB; + m_mass.col1.y = m_mass.col2.x; + m_mass.col2.y = mA + mB + rA.x * rA.x * iA + rB.x * rB.x * iB; + m_mass.col3.y = rA.x * iA + rB.x * iB; + m_mass.col1.z = m_mass.col3.x; + m_mass.col2.z = m_mass.col3.y; + m_mass.col3.z = iA + iB; + + if (step.warmStarting) + { + // Scale impulses to support a variable time step. + m_impulse *= step.dtRatio; + + b2Vec2 P(m_impulse.x, m_impulse.y); + + bA->m_linearVelocity -= mA * P; + bA->m_angularVelocity -= iA * (b2Cross(rA, P) + m_impulse.z); + + bB->m_linearVelocity += mB * P; + bB->m_angularVelocity += iB * (b2Cross(rB, P) + m_impulse.z); + } + else + { + m_impulse.SetZero(); + } +} + +void b2WeldJoint::SolveVelocityConstraints(const b2TimeStep& step) +{ + B2_NOT_USED(step); + + b2Body* bA = m_bodyA; + b2Body* bB = m_bodyB; + + b2Vec2 vA = bA->m_linearVelocity; + float32 wA = bA->m_angularVelocity; + b2Vec2 vB = bB->m_linearVelocity; + float32 wB = bB->m_angularVelocity; + + float32 mA = bA->m_invMass, mB = bB->m_invMass; + float32 iA = bA->m_invI, iB = bB->m_invI; + + b2Vec2 rA = b2Mul(bA->GetTransform().R, m_localAnchorA - bA->GetLocalCenter()); + b2Vec2 rB = b2Mul(bB->GetTransform().R, m_localAnchorB - bB->GetLocalCenter()); + + // Solve point-to-point constraint + b2Vec2 Cdot1 = vB + b2Cross(wB, rB) - vA - b2Cross(wA, rA); + float32 Cdot2 = wB - wA; + b2Vec3 Cdot(Cdot1.x, Cdot1.y, Cdot2); + + b2Vec3 impulse = m_mass.Solve33(-Cdot); + m_impulse += impulse; + + b2Vec2 P(impulse.x, impulse.y); + + vA -= mA * P; + wA -= iA * (b2Cross(rA, P) + impulse.z); + + vB += mB * P; + wB += iB * (b2Cross(rB, P) + impulse.z); + + bA->m_linearVelocity = vA; + bA->m_angularVelocity = wA; + bB->m_linearVelocity = vB; + bB->m_angularVelocity = wB; +} + +bool b2WeldJoint::SolvePositionConstraints(float32 baumgarte) +{ + B2_NOT_USED(baumgarte); + + b2Body* bA = m_bodyA; + b2Body* bB = m_bodyB; + + float32 mA = bA->m_invMass, mB = bB->m_invMass; + float32 iA = bA->m_invI, iB = bB->m_invI; + + b2Vec2 rA = b2Mul(bA->GetTransform().R, m_localAnchorA - bA->GetLocalCenter()); + b2Vec2 rB = b2Mul(bB->GetTransform().R, m_localAnchorB - bB->GetLocalCenter()); + + b2Vec2 C1 = bB->m_sweep.c + rB - bA->m_sweep.c - rA; + float32 C2 = bB->m_sweep.a - bA->m_sweep.a - m_referenceAngle; + + // Handle large detachment. + const float32 k_allowedStretch = 10.0f * b2_linearSlop; + float32 positionError = C1.Length(); + float32 angularError = b2Abs(C2); + if (positionError > k_allowedStretch) + { + iA *= 1.0f; + iB *= 1.0f; + } + + m_mass.col1.x = mA + mB + rA.y * rA.y * iA + rB.y * rB.y * iB; + m_mass.col2.x = -rA.y * rA.x * iA - rB.y * rB.x * iB; + m_mass.col3.x = -rA.y * iA - rB.y * iB; + m_mass.col1.y = m_mass.col2.x; + m_mass.col2.y = mA + mB + rA.x * rA.x * iA + rB.x * rB.x * iB; + m_mass.col3.y = rA.x * iA + rB.x * iB; + m_mass.col1.z = m_mass.col3.x; + m_mass.col2.z = m_mass.col3.y; + m_mass.col3.z = iA + iB; + + b2Vec3 C(C1.x, C1.y, C2); + + b2Vec3 impulse = m_mass.Solve33(-C); + + b2Vec2 P(impulse.x, impulse.y); + + bA->m_sweep.c -= mA * P; + bA->m_sweep.a -= iA * (b2Cross(rA, P) + impulse.z); + + bB->m_sweep.c += mB * P; + bB->m_sweep.a += iB * (b2Cross(rB, P) + impulse.z); + + bA->SynchronizeTransform(); + bB->SynchronizeTransform(); + + return positionError <= b2_linearSlop && angularError <= b2_angularSlop; +} + +b2Vec2 b2WeldJoint::GetAnchorA() const +{ + return m_bodyA->GetWorldPoint(m_localAnchorA); +} + +b2Vec2 b2WeldJoint::GetAnchorB() const +{ + return m_bodyB->GetWorldPoint(m_localAnchorB); +} + +b2Vec2 b2WeldJoint::GetReactionForce(float32 inv_dt) const +{ + b2Vec2 P(m_impulse.x, m_impulse.y); + return inv_dt * P; +} + +float32 b2WeldJoint::GetReactionTorque(float32 inv_dt) const +{ + return inv_dt * m_impulse.z; +} diff --git a/uppsrc/plugin/box2d/b2WeldJoint.h b/uppsrc/plugin/box2d/b2WeldJoint.h new file mode 100644 index 000000000..f107b56ca --- /dev/null +++ b/uppsrc/plugin/box2d/b2WeldJoint.h @@ -0,0 +1,82 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_WELD_JOINT_H +#define B2_WELD_JOINT_H + +#include "b2Joint.h" + +/// Weld joint definition. You need to specify local anchor points +/// where they are attached and the relative body angle. The position +/// of the anchor points is important for computing the reaction torque. +struct b2WeldJointDef : public b2JointDef +{ + b2WeldJointDef() + { + type = e_weldJoint; + localAnchorA.Set(0.0f, 0.0f); + localAnchorB.Set(0.0f, 0.0f); + referenceAngle = 0.0f; + } + + /// Initialize the bodies, anchors, and reference angle using a world + /// anchor point. + void Initialize(b2Body* body1, b2Body* body2, const b2Vec2& anchor); + + /// The local anchor point relative to body1's origin. + b2Vec2 localAnchorA; + + /// The local anchor point relative to body2's origin. + b2Vec2 localAnchorB; + + /// The body2 angle minus body1 angle in the reference state (radians). + float32 referenceAngle; +}; + +/// A weld joint essentially glues two bodies together. A weld joint may +/// distort somewhat because the island constraint solver is approximate. +class b2WeldJoint : public b2Joint +{ +public: + b2Vec2 GetAnchorA() const; + b2Vec2 GetAnchorB() const; + + b2Vec2 GetReactionForce(float32 inv_dt) const; + float32 GetReactionTorque(float32 inv_dt) const; + +protected: + + friend class b2Joint; + + b2WeldJoint(const b2WeldJointDef* def); + + void InitVelocityConstraints(const b2TimeStep& step); + void SolveVelocityConstraints(const b2TimeStep& step); + + bool SolvePositionConstraints(float32 baumgarte); + + b2Vec2 m_localAnchorA; + b2Vec2 m_localAnchorB; + float32 m_referenceAngle; + + b2Vec3 m_impulse; + + b2Mat33 m_mass; +}; + +#endif diff --git a/uppsrc/plugin/box2d/b2World.cpp b/uppsrc/plugin/box2d/b2World.cpp new file mode 100644 index 000000000..11fd3c8a0 --- /dev/null +++ b/uppsrc/plugin/box2d/b2World.cpp @@ -0,0 +1,1076 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2World.h" +#include "b2Body.h" +#include "b2Fixture.h" +#include "b2Island.h" +#include "b2PulleyJoint.h" +#include "b2Contact.h" +#include "b2ContactSolver.h" +#include "b2TOISolver.h" +#include "b2Collision.h" +#include "b2BroadPhase.h" +#include "b2CircleShape.h" +#include "b2PolygonShape.h" +#include "b2TimeOfImpact.h" +#include + +b2World::b2World(const b2Vec2& gravity, bool doSleep) +{ + m_destructionListener = NULL; + m_debugDraw = NULL; + + m_bodyList = NULL; + m_jointList = NULL; + + m_bodyCount = 0; + m_jointCount = 0; + + m_warmStarting = true; + m_continuousPhysics = true; + + m_allowSleep = doSleep; + m_gravity = gravity; + + m_flags = e_clearForces; + + m_inv_dt0 = 0.0f; + + m_contactManager.m_allocator = &m_blockAllocator; +} + +b2World::~b2World() +{ +} + +void b2World::SetDestructionListener(b2DestructionListener* listener) +{ + m_destructionListener = listener; +} + +void b2World::SetContactFilter(b2ContactFilter* filter) +{ + m_contactManager.m_contactFilter = filter; +} + +void b2World::SetContactListener(b2ContactListener* listener) +{ + m_contactManager.m_contactListener = listener; +} + +void b2World::SetDebugDraw(b2DebugDraw* debugDraw) +{ + m_debugDraw = debugDraw; +} + +b2Body* b2World::CreateBody(const b2BodyDef* def) +{ + b2Assert(IsLocked() == false); + if (IsLocked()) + { + return NULL; + } + + void* mem = m_blockAllocator.Allocate(sizeof(b2Body)); + b2Body* b = new (mem) b2Body(def, this); + + // Add to world doubly linked list. + b->m_prev = NULL; + b->m_next = m_bodyList; + if (m_bodyList) + { + m_bodyList->m_prev = b; + } + m_bodyList = b; + ++m_bodyCount; + + return b; +} + +void b2World::DestroyBody(b2Body* b) +{ + b2Assert(m_bodyCount > 0); + b2Assert(IsLocked() == false); + if (IsLocked()) + { + return; + } + + // Delete the attached joints. + b2JointEdge* je = b->m_jointList; + while (je) + { + b2JointEdge* je0 = je; + je = je->next; + + if (m_destructionListener) + { + m_destructionListener->SayGoodbye(je0->joint); + } + + DestroyJoint(je0->joint); + } + b->m_jointList = NULL; + + // Delete the attached contacts. + b2ContactEdge* ce = b->m_contactList; + while (ce) + { + b2ContactEdge* ce0 = ce; + ce = ce->next; + m_contactManager.Destroy(ce0->contact); + } + b->m_contactList = NULL; + + // Delete the attached fixtures. This destroys broad-phase proxies. + b2Fixture* f = b->m_fixtureList; + while (f) + { + b2Fixture* f0 = f; + f = f->m_next; + + if (m_destructionListener) + { + m_destructionListener->SayGoodbye(f0); + } + + f0->DestroyProxy(&m_contactManager.m_broadPhase); + f0->Destroy(&m_blockAllocator); + f0->~b2Fixture(); + m_blockAllocator.Free(f0, sizeof(b2Fixture)); + } + b->m_fixtureList = NULL; + b->m_fixtureCount = 0; + + // Remove world body list. + if (b->m_prev) + { + b->m_prev->m_next = b->m_next; + } + + if (b->m_next) + { + b->m_next->m_prev = b->m_prev; + } + + if (b == m_bodyList) + { + m_bodyList = b->m_next; + } + + --m_bodyCount; + b->~b2Body(); + m_blockAllocator.Free(b, sizeof(b2Body)); +} + +b2Joint* b2World::CreateJoint(const b2JointDef* def) +{ + b2Assert(IsLocked() == false); + if (IsLocked()) + { + return NULL; + } + + b2Joint* j = b2Joint::Create(def, &m_blockAllocator); + + // Connect to the world list. + j->m_prev = NULL; + j->m_next = m_jointList; + if (m_jointList) + { + m_jointList->m_prev = j; + } + m_jointList = j; + ++m_jointCount; + + // Connect to the bodies' doubly linked lists. + j->m_edgeA.joint = j; + j->m_edgeA.other = j->m_bodyB; + j->m_edgeA.prev = NULL; + j->m_edgeA.next = j->m_bodyA->m_jointList; + if (j->m_bodyA->m_jointList) j->m_bodyA->m_jointList->prev = &j->m_edgeA; + j->m_bodyA->m_jointList = &j->m_edgeA; + + j->m_edgeB.joint = j; + j->m_edgeB.other = j->m_bodyA; + j->m_edgeB.prev = NULL; + j->m_edgeB.next = j->m_bodyB->m_jointList; + if (j->m_bodyB->m_jointList) j->m_bodyB->m_jointList->prev = &j->m_edgeB; + j->m_bodyB->m_jointList = &j->m_edgeB; + + b2Body* bodyA = def->bodyA; + b2Body* bodyB = def->bodyB; + + // If the joint prevents collisions, then flag any contacts for filtering. + if (def->collideConnected == false) + { + b2ContactEdge* edge = bodyB->GetContactList(); + while (edge) + { + if (edge->other == bodyA) + { + // Flag the contact for filtering at the next time step (where either + // body is awake). + edge->contact->FlagForFiltering(); + } + + edge = edge->next; + } + } + + // Note: creating a joint doesn't wake the bodies. + + return j; +} + +void b2World::DestroyJoint(b2Joint* j) +{ + b2Assert(IsLocked() == false); + if (IsLocked()) + { + return; + } + + bool collideConnected = j->m_collideConnected; + + // Remove from the doubly linked list. + if (j->m_prev) + { + j->m_prev->m_next = j->m_next; + } + + if (j->m_next) + { + j->m_next->m_prev = j->m_prev; + } + + if (j == m_jointList) + { + m_jointList = j->m_next; + } + + // Disconnect from island graph. + b2Body* bodyA = j->m_bodyA; + b2Body* bodyB = j->m_bodyB; + + // Wake up connected bodies. + bodyA->SetAwake(true); + bodyB->SetAwake(true); + + // Remove from body 1. + if (j->m_edgeA.prev) + { + j->m_edgeA.prev->next = j->m_edgeA.next; + } + + if (j->m_edgeA.next) + { + j->m_edgeA.next->prev = j->m_edgeA.prev; + } + + if (&j->m_edgeA == bodyA->m_jointList) + { + bodyA->m_jointList = j->m_edgeA.next; + } + + j->m_edgeA.prev = NULL; + j->m_edgeA.next = NULL; + + // Remove from body 2 + if (j->m_edgeB.prev) + { + j->m_edgeB.prev->next = j->m_edgeB.next; + } + + if (j->m_edgeB.next) + { + j->m_edgeB.next->prev = j->m_edgeB.prev; + } + + if (&j->m_edgeB == bodyB->m_jointList) + { + bodyB->m_jointList = j->m_edgeB.next; + } + + j->m_edgeB.prev = NULL; + j->m_edgeB.next = NULL; + + b2Joint::Destroy(j, &m_blockAllocator); + + b2Assert(m_jointCount > 0); + --m_jointCount; + + // If the joint prevents collisions, then flag any contacts for filtering. + if (collideConnected == false) + { + b2ContactEdge* edge = bodyB->GetContactList(); + while (edge) + { + if (edge->other == bodyA) + { + // Flag the contact for filtering at the next time step (where either + // body is awake). + edge->contact->FlagForFiltering(); + } + + edge = edge->next; + } + } +} + +// Find islands, integrate and solve constraints, solve position constraints +void b2World::Solve(const b2TimeStep& step) +{ + // Size the island for the worst case. + b2Island island(m_bodyCount, + m_contactManager.m_contactCount, + m_jointCount, + &m_stackAllocator, + m_contactManager.m_contactListener); + + // Clear all the island flags. + for (b2Body* b = m_bodyList; b; b = b->m_next) + { + b->m_flags &= ~b2Body::e_islandFlag; + } + for (b2Contact* c = m_contactManager.m_contactList; c; c = c->m_next) + { + c->m_flags &= ~b2Contact::e_islandFlag; + } + for (b2Joint* j = m_jointList; j; j = j->m_next) + { + j->m_islandFlag = false; + } + + // Build and simulate all awake islands. + int32 stackSize = m_bodyCount; + b2Body** stack = (b2Body**)m_stackAllocator.Allocate(stackSize * sizeof(b2Body*)); + for (b2Body* seed = m_bodyList; seed; seed = seed->m_next) + { + if (seed->m_flags & b2Body::e_islandFlag) + { + continue; + } + + if (seed->IsAwake() == false || seed->IsActive() == false) + { + continue; + } + + // The seed can be dynamic or kinematic. + if (seed->GetType() == b2_staticBody) + { + continue; + } + + // Reset island and stack. + island.Clear(); + int32 stackCount = 0; + stack[stackCount++] = seed; + seed->m_flags |= b2Body::e_islandFlag; + + // Perform a depth first search (DFS) on the constraint graph. + while (stackCount > 0) + { + // Grab the next body off the stack and add it to the island. + b2Body* b = stack[--stackCount]; + b2Assert(b->IsActive() == true); + island.Add(b); + + // Make sure the body is awake. + b->SetAwake(true); + + // To keep islands as small as possible, we don't + // propagate islands across static bodies. + if (b->GetType() == b2_staticBody) + { + continue; + } + + // Search all contacts connected to this body. + for (b2ContactEdge* ce = b->m_contactList; ce; ce = ce->next) + { + b2Contact* contact = ce->contact; + + // Has this contact already been added to an island? + if (contact->m_flags & b2Contact::e_islandFlag) + { + continue; + } + + // Is this contact solid and touching? + if (contact->IsEnabled() == false || + contact->IsTouching() == false) + { + continue; + } + + // Skip sensors. + bool sensorA = contact->m_fixtureA->m_isSensor; + bool sensorB = contact->m_fixtureB->m_isSensor; + if (sensorA || sensorB) + { + continue; + } + + island.Add(contact); + contact->m_flags |= b2Contact::e_islandFlag; + + b2Body* other = ce->other; + + // Was the other body already added to this island? + if (other->m_flags & b2Body::e_islandFlag) + { + continue; + } + + b2Assert(stackCount < stackSize); + stack[stackCount++] = other; + other->m_flags |= b2Body::e_islandFlag; + } + + // Search all joints connect to this body. + for (b2JointEdge* je = b->m_jointList; je; je = je->next) + { + if (je->joint->m_islandFlag == true) + { + continue; + } + + b2Body* other = je->other; + + // Don't simulate joints connected to inactive bodies. + if (other->IsActive() == false) + { + continue; + } + + island.Add(je->joint); + je->joint->m_islandFlag = true; + + if (other->m_flags & b2Body::e_islandFlag) + { + continue; + } + + b2Assert(stackCount < stackSize); + stack[stackCount++] = other; + other->m_flags |= b2Body::e_islandFlag; + } + } + + island.Solve(step, m_gravity, m_allowSleep); + + // Post solve cleanup. + for (int32 i = 0; i < island.m_bodyCount; ++i) + { + // Allow static bodies to participate in other islands. + b2Body* b = island.m_bodies[i]; + if (b->GetType() == b2_staticBody) + { + b->m_flags &= ~b2Body::e_islandFlag; + } + } + } + + m_stackAllocator.Free(stack); + + // Synchronize fixtures, check for out of range bodies. + for (b2Body* b = m_bodyList; b; b = b->GetNext()) + { + // If a body was not in an island then it did not move. + if ((b->m_flags & b2Body::e_islandFlag) == 0) + { + continue; + } + + if (b->GetType() == b2_staticBody) + { + continue; + } + + // Update fixtures (for broad-phase). + b->SynchronizeFixtures(); + } + + // Look for new contacts. + m_contactManager.FindNewContacts(); +} + +// Advance a dynamic body to its first time of contact +// and adjust the position to ensure clearance. +void b2World::SolveTOI(b2Body* body) +{ + // Find the minimum contact. + b2Contact* toiContact = NULL; + float32 toi = 1.0f; + b2Body* toiOther = NULL; + bool found; + int32 count; + int32 iter = 0; + + bool bullet = body->IsBullet(); + + // Iterate until all contacts agree on the minimum TOI. We have + // to iterate because the TOI algorithm may skip some intermediate + // collisions when objects rotate through each other. + do + { + count = 0; + found = false; + for (b2ContactEdge* ce = body->m_contactList; ce; ce = ce->next) + { + if (ce->contact == toiContact) + { + continue; + } + + b2Body* other = ce->other; + b2BodyType type = other->GetType(); + + // Only bullets perform TOI with dynamic bodies. + if (bullet == true) + { + // Bullets only perform TOI with bodies that have their TOI resolved. + if ((other->m_flags & b2Body::e_toiFlag) == 0) + { + continue; + } + + // No repeated hits on non-static bodies + if (type != b2_staticBody && (ce->contact->m_flags & b2Contact::e_bulletHitFlag) != 0) + { + continue; + } + } + else if (type == b2_dynamicBody) + { + continue; + } + + // Check for a disabled contact. + b2Contact* contact = ce->contact; + if (contact->IsEnabled() == false) + { + continue; + } + + // Prevent infinite looping. + if (contact->m_toiCount > 10) + { + continue; + } + + b2Fixture* fixtureA = contact->m_fixtureA; + b2Fixture* fixtureB = contact->m_fixtureB; + + // Cull sensors. + if (fixtureA->IsSensor() || fixtureB->IsSensor()) + { + continue; + } + + b2Body* bodyA = fixtureA->m_body; + b2Body* bodyB = fixtureB->m_body; + + // Compute the time of impact in interval [0, minTOI] + b2TOIInput input; + input.proxyA.Set(fixtureA->GetShape()); + input.proxyB.Set(fixtureB->GetShape()); + input.sweepA = bodyA->m_sweep; + input.sweepB = bodyB->m_sweep; + input.tMax = toi; + + b2TOIOutput output; + b2TimeOfImpact(&output, &input); + + if (output.state == b2TOIOutput::e_touching && output.t < toi) + { + toiContact = contact; + toi = output.t; + toiOther = other; + found = true; + } + + ++count; + } + + ++iter; + } while (found && count > 1 && iter < 50); + + if (toiContact == NULL) + { + body->Advance(1.0f); + return; + } + + b2Sweep backup = body->m_sweep; + body->Advance(toi); + toiContact->Update(m_contactManager.m_contactListener); + if (toiContact->IsEnabled() == false) + { + // Contact disabled. Backup and recurse. + body->m_sweep = backup; + SolveTOI(body); + } + + ++toiContact->m_toiCount; + + // Update all the valid contacts on this body and build a contact island. + b2Contact* contacts[b2_maxTOIContacts]; + count = 0; + for (b2ContactEdge* ce = body->m_contactList; ce && count < b2_maxTOIContacts; ce = ce->next) + { + b2Body* other = ce->other; + b2BodyType type = other->GetType(); + + // Only perform correction with static bodies, so the + // body won't get pushed out of the world. + if (type == b2_dynamicBody) + { + continue; + } + + // Check for a disabled contact. + b2Contact* contact = ce->contact; + if (contact->IsEnabled() == false) + { + continue; + } + + b2Fixture* fixtureA = contact->m_fixtureA; + b2Fixture* fixtureB = contact->m_fixtureB; + + // Cull sensors. + if (fixtureA->IsSensor() || fixtureB->IsSensor()) + { + continue; + } + + // The contact likely has some new contact points. The listener + // gives the user a chance to disable the contact. + if (contact != toiContact) + { + contact->Update(m_contactManager.m_contactListener); + } + + // Did the user disable the contact? + if (contact->IsEnabled() == false) + { + // Skip this contact. + continue; + } + + if (contact->IsTouching() == false) + { + continue; + } + + contacts[count] = contact; + ++count; + } + + // Reduce the TOI body's overlap with the contact island. + b2TOISolver solver(&m_stackAllocator); + solver.Initialize(contacts, count, body); + + const float32 k_toiBaumgarte = 0.75f; + bool solved = false; + for (int32 i = 0; i < 20; ++i) + { + bool contactsOkay = solver.Solve(k_toiBaumgarte); + if (contactsOkay) + { + solved = true; + break; + } + } + + if (toiOther->GetType() != b2_staticBody) + { + toiContact->m_flags |= b2Contact::e_bulletHitFlag; + } +} + +// Sequentially solve TOIs for each body. We bring each +// body to the time of contact and perform some position correction. +// Time is not conserved. +void b2World::SolveTOI() +{ + // Prepare all contacts. + for (b2Contact* c = m_contactManager.m_contactList; c; c = c->m_next) + { + // Enable the contact + c->m_flags |= b2Contact::e_enabledFlag; + + // Set the number of TOI events for this contact to zero. + c->m_toiCount = 0; + } + + // Initialize the TOI flag. + for (b2Body* body = m_bodyList; body; body = body->m_next) + { + // Kinematic, and static bodies will not be affected by the TOI event. + // If a body was not in an island then it did not move. + if ((body->m_flags & b2Body::e_islandFlag) == 0 || body->GetType() == b2_kinematicBody || body->GetType() == b2_staticBody) + { + body->m_flags |= b2Body::e_toiFlag; + } + else + { + body->m_flags &= ~b2Body::e_toiFlag; + } + } + + // Collide non-bullets. + for (b2Body* body = m_bodyList; body; body = body->m_next) + { + if (body->m_flags & b2Body::e_toiFlag) + { + continue; + } + + if (body->IsBullet() == true) + { + continue; + } + + SolveTOI(body); + + body->m_flags |= b2Body::e_toiFlag; + } + + // Collide bullets. + for (b2Body* body = m_bodyList; body; body = body->m_next) + { + if (body->m_flags & b2Body::e_toiFlag) + { + continue; + } + + if (body->IsBullet() == false) + { + continue; + } + + SolveTOI(body); + + body->m_flags |= b2Body::e_toiFlag; + } +} + +void b2World::Step(float32 dt, int32 velocityIterations, int32 positionIterations) +{ + // If new fixtures were added, we need to find the new contacts. + if (m_flags & e_newFixture) + { + m_contactManager.FindNewContacts(); + m_flags &= ~e_newFixture; + } + + m_flags |= e_locked; + + b2TimeStep step; + step.dt = dt; + step.velocityIterations = velocityIterations; + step.positionIterations = positionIterations; + if (dt > 0.0f) + { + step.inv_dt = 1.0f / dt; + } + else + { + step.inv_dt = 0.0f; + } + + step.dtRatio = m_inv_dt0 * dt; + + step.warmStarting = m_warmStarting; + + // Update contacts. This is where some contacts are destroyed. + m_contactManager.Collide(); + + // Integrate velocities, solve velocity constraints, and integrate positions. + if (step.dt > 0.0f) + { + Solve(step); + } + + // Handle TOI events. + if (m_continuousPhysics && step.dt > 0.0f) + { + SolveTOI(); + } + + if (step.dt > 0.0f) + { + m_inv_dt0 = step.inv_dt; + } + + if (m_flags & e_clearForces) + { + ClearForces(); + } + + m_flags &= ~e_locked; +} + +void b2World::ClearForces() +{ + for (b2Body* body = m_bodyList; body; body = body->GetNext()) + { + body->m_force.SetZero(); + body->m_torque = 0.0f; + } +} + +struct b2WorldQueryWrapper +{ + bool QueryCallback(int32 proxyId) + { + b2Fixture* fixture = (b2Fixture*)broadPhase->GetUserData(proxyId); + return callback->ReportFixture(fixture); + } + + const b2BroadPhase* broadPhase; + b2QueryCallback* callback; +}; + +void b2World::QueryAABB(b2QueryCallback* callback, const b2AABB& aabb) const +{ + b2WorldQueryWrapper wrapper; + wrapper.broadPhase = &m_contactManager.m_broadPhase; + wrapper.callback = callback; + m_contactManager.m_broadPhase.Query(&wrapper, aabb); +} + +struct b2WorldRayCastWrapper +{ + float32 RayCastCallback(const b2RayCastInput& input, int32 proxyId) + { + void* userData = broadPhase->GetUserData(proxyId); + b2Fixture* fixture = (b2Fixture*)userData; + b2RayCastOutput output; + bool hit = fixture->RayCast(&output, input); + + if (hit) + { + float32 fraction = output.fraction; + b2Vec2 point = (1.0f - fraction) * input.p1 + fraction * input.p2; + return callback->ReportFixture(fixture, point, output.normal, fraction); + } + + return input.maxFraction; + } + + const b2BroadPhase* broadPhase; + b2RayCastCallback* callback; +}; + +void b2World::RayCast(b2RayCastCallback* callback, const b2Vec2& point1, const b2Vec2& point2) const +{ + b2WorldRayCastWrapper wrapper; + wrapper.broadPhase = &m_contactManager.m_broadPhase; + wrapper.callback = callback; + b2RayCastInput input; + input.maxFraction = 1.0f; + input.p1 = point1; + input.p2 = point2; + m_contactManager.m_broadPhase.RayCast(&wrapper, input); +} + +void b2World::DrawShape(b2Fixture* fixture, const b2Transform& xf, const b2Color& color) +{ + switch (fixture->GetType()) + { + case b2Shape::e_circle: + { + b2CircleShape* circle = (b2CircleShape*)fixture->GetShape(); + + b2Vec2 center = b2Mul(xf, circle->m_p); + float32 radius = circle->m_radius; + b2Vec2 axis = xf.R.col1; + + m_debugDraw->DrawSolidCircle(center, radius, axis, color); + } + break; + + case b2Shape::e_polygon: + { + b2PolygonShape* poly = (b2PolygonShape*)fixture->GetShape(); + int32 vertexCount = poly->m_vertexCount; + b2Assert(vertexCount <= b2_maxPolygonVertices); + b2Vec2 vertices[b2_maxPolygonVertices]; + + for (int32 i = 0; i < vertexCount; ++i) + { + vertices[i] = b2Mul(xf, poly->m_vertices[i]); + } + + m_debugDraw->DrawSolidPolygon(vertices, vertexCount, color); + } + break; + } +} + +void b2World::DrawJoint(b2Joint* joint) +{ + b2Body* bodyA = joint->GetBodyA(); + b2Body* bodyB = joint->GetBodyB(); + const b2Transform& xf1 = bodyA->GetTransform(); + const b2Transform& xf2 = bodyB->GetTransform(); + b2Vec2 x1 = xf1.position; + b2Vec2 x2 = xf2.position; + b2Vec2 p1 = joint->GetAnchorA(); + b2Vec2 p2 = joint->GetAnchorB(); + + b2Color color(0.5f, 0.8f, 0.8f); + + switch (joint->GetType()) + { + case e_distanceJoint: + m_debugDraw->DrawSegment(p1, p2, color); + break; + + case e_pulleyJoint: + { + b2PulleyJoint* pulley = (b2PulleyJoint*)joint; + b2Vec2 s1 = pulley->GetGroundAnchorA(); + b2Vec2 s2 = pulley->GetGroundAnchorB(); + m_debugDraw->DrawSegment(s1, p1, color); + m_debugDraw->DrawSegment(s2, p2, color); + m_debugDraw->DrawSegment(s1, s2, color); + } + break; + + case e_mouseJoint: + // don't draw this + break; + + default: + m_debugDraw->DrawSegment(x1, p1, color); + m_debugDraw->DrawSegment(p1, p2, color); + m_debugDraw->DrawSegment(x2, p2, color); + } +} + +void b2World::DrawDebugData() +{ + if (m_debugDraw == NULL) + { + return; + } + + uint32 flags = m_debugDraw->GetFlags(); + + if (flags & b2DebugDraw::e_shapeBit) + { + for (b2Body* b = m_bodyList; b; b = b->GetNext()) + { + const b2Transform& xf = b->GetTransform(); + for (b2Fixture* f = b->GetFixtureList(); f; f = f->GetNext()) + { + if (b->IsActive() == false) + { + DrawShape(f, xf, b2Color(0.5f, 0.5f, 0.3f)); + } + else if (b->GetType() == b2_staticBody) + { + DrawShape(f, xf, b2Color(0.5f, 0.9f, 0.5f)); + } + else if (b->GetType() == b2_kinematicBody) + { + DrawShape(f, xf, b2Color(0.5f, 0.5f, 0.9f)); + } + else if (b->IsAwake() == false) + { + DrawShape(f, xf, b2Color(0.6f, 0.6f, 0.6f)); + } + else + { + DrawShape(f, xf, b2Color(0.9f, 0.7f, 0.7f)); + } + } + } + } + + if (flags & b2DebugDraw::e_jointBit) + { + for (b2Joint* j = m_jointList; j; j = j->GetNext()) + { + DrawJoint(j); + } + } + + if (flags & b2DebugDraw::e_pairBit) + { + b2Color color(0.3f, 0.9f, 0.9f); + for (b2Contact* c = m_contactManager.m_contactList; c; c = c->GetNext()) + { + b2Fixture* fixtureA = c->GetFixtureA(); + b2Fixture* fixtureB = c->GetFixtureB(); + + b2Vec2 cA = fixtureA->GetAABB().GetCenter(); + b2Vec2 cB = fixtureB->GetAABB().GetCenter(); + + m_debugDraw->DrawSegment(cA, cB, color); + } + } + + if (flags & b2DebugDraw::e_aabbBit) + { + b2Color color(0.9f, 0.3f, 0.9f); + b2BroadPhase* bp = &m_contactManager.m_broadPhase; + + for (b2Body* b = m_bodyList; b; b = b->GetNext()) + { + if (b->IsActive() == false) + { + continue; + } + + for (b2Fixture* f = b->GetFixtureList(); f; f = f->GetNext()) + { + b2AABB aabb = bp->GetFatAABB(f->m_proxyId); + b2Vec2 vs[4]; + vs[0].Set(aabb.lowerBound.x, aabb.lowerBound.y); + vs[1].Set(aabb.upperBound.x, aabb.lowerBound.y); + vs[2].Set(aabb.upperBound.x, aabb.upperBound.y); + vs[3].Set(aabb.lowerBound.x, aabb.upperBound.y); + + m_debugDraw->DrawPolygon(vs, 4, color); + } + } + } + + if (flags & b2DebugDraw::e_centerOfMassBit) + { + for (b2Body* b = m_bodyList; b; b = b->GetNext()) + { + b2Transform xf = b->GetTransform(); + xf.position = b->GetWorldCenter(); + m_debugDraw->DrawTransform(xf); + } + } +} + +int32 b2World::GetProxyCount() const +{ + return m_contactManager.m_broadPhase.GetProxyCount(); +} diff --git a/uppsrc/plugin/box2d/b2World.h b/uppsrc/plugin/box2d/b2World.h new file mode 100644 index 000000000..5de8a7571 --- /dev/null +++ b/uppsrc/plugin/box2d/b2World.h @@ -0,0 +1,285 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_WORLD_H +#define B2_WORLD_H + +#include "b2Math.h" +#include "b2BlockAllocator.h" +#include "b2StackAllocator.h" +#include "b2ContactManager.h" +#include "b2WorldCallbacks.h" + +struct b2AABB; +struct b2BodyDef; +struct b2JointDef; +struct b2TimeStep; +class b2Body; +class b2Fixture; +class b2Joint; + +/// The world class manages all physics entities, dynamic simulation, +/// and asynchronous queries. The world also contains efficient memory +/// management facilities. +class b2World +{ +public: + /// Construct a world object. + /// @param gravity the world gravity vector. + /// @param doSleep improve performance by not simulating inactive bodies. + b2World(const b2Vec2& gravity, bool doSleep); + + /// Destruct the world. All physics entities are destroyed and all heap memory is released. + ~b2World(); + + /// Register a destruction listener. The listener is owned by you and must + /// remain in scope. + void SetDestructionListener(b2DestructionListener* listener); + + /// Register a contact filter to provide specific control over collision. + /// Otherwise the default filter is used (b2_defaultFilter). The listener is + /// owned by you and must remain in scope. + void SetContactFilter(b2ContactFilter* filter); + + /// Register a contact event listener. The listener is owned by you and must + /// remain in scope. + void SetContactListener(b2ContactListener* listener); + + /// Register a routine for debug drawing. The debug draw functions are called + /// inside with b2World::DrawDebugData method. The debug draw object is owned + /// by you and must remain in scope. + void SetDebugDraw(b2DebugDraw* debugDraw); + + /// Create a rigid body given a definition. No reference to the definition + /// is retained. + /// @warning This function is locked during callbacks. + b2Body* CreateBody(const b2BodyDef* def); + + /// Destroy a rigid body given a definition. No reference to the definition + /// is retained. This function is locked during callbacks. + /// @warning This automatically deletes all associated shapes and joints. + /// @warning This function is locked during callbacks. + void DestroyBody(b2Body* body); + + /// Create a joint to constrain bodies together. No reference to the definition + /// is retained. This may cause the connected bodies to cease colliding. + /// @warning This function is locked during callbacks. + b2Joint* CreateJoint(const b2JointDef* def); + + /// Destroy a joint. This may cause the connected bodies to begin colliding. + /// @warning This function is locked during callbacks. + void DestroyJoint(b2Joint* joint); + + /// Take a time step. This performs collision detection, integration, + /// and constraint solution. + /// @param timeStep the amount of time to simulate, this should not vary. + /// @param velocityIterations for the velocity constraint solver. + /// @param positionIterations for the position constraint solver. + void Step( float32 timeStep, + int32 velocityIterations, + int32 positionIterations); + + /// Call this after you are done with time steps to clear the forces. You normally + /// call this after each call to Step, unless you are performing sub-steps. By default, + /// forces will be automatically cleared, so you don't need to call this function. + /// @see SetAutoClearForces + void ClearForces(); + + /// Call this to draw shapes and other debug draw data. + void DrawDebugData(); + + /// Query the world for all fixtures that potentially overlap the + /// provided AABB. + /// @param callback a user implemented callback class. + /// @param aabb the query box. + void QueryAABB(b2QueryCallback* callback, const b2AABB& aabb) const; + + /// Ray-cast the world for all fixtures in the path of the ray. Your callback + /// controls whether you get the closest point, any point, or n-points. + /// The ray-cast ignores shapes that contain the starting point. + /// @param callback a user implemented callback class. + /// @param point1 the ray starting point + /// @param point2 the ray ending point + void RayCast(b2RayCastCallback* callback, const b2Vec2& point1, const b2Vec2& point2) const; + + /// Get the world body list. With the returned body, use b2Body::GetNext to get + /// the next body in the world list. A NULL body indicates the end of the list. + /// @return the head of the world body list. + b2Body* GetBodyList(); + + /// Get the world joint list. With the returned joint, use b2Joint::GetNext to get + /// the next joint in the world list. A NULL joint indicates the end of the list. + /// @return the head of the world joint list. + b2Joint* GetJointList(); + + /// Get the world contact list. With the returned contact, use b2Contact::GetNext to get + /// the next contact in the world list. A NULL contact indicates the end of the list. + /// @return the head of the world contact list. + /// @warning contacts are + b2Contact* GetContactList(); + + /// Enable/disable warm starting. For testing. + void SetWarmStarting(bool flag) { m_warmStarting = flag; } + + /// Enable/disable continuous physics. For testing. + void SetContinuousPhysics(bool flag) { m_continuousPhysics = flag; } + + /// Get the number of broad-phase proxies. + int32 GetProxyCount() const; + + /// Get the number of bodies. + int32 GetBodyCount() const; + + /// Get the number of joints. + int32 GetJointCount() const; + + /// Get the number of contacts (each may have 0 or more contact points). + int32 GetContactCount() const; + + /// Change the global gravity vector. + void SetGravity(const b2Vec2& gravity); + + /// Get the global gravity vector. + b2Vec2 GetGravity() const; + + /// Is the world locked (in the middle of a time step). + bool IsLocked() const; + + /// Set flag to control automatic clearing of forces after each time step. + void SetAutoClearForces(bool flag); + + /// Get the flag that controls automatic clearing of forces after each time step. + bool GetAutoClearForces() const; + +private: + + // m_flags + enum + { + e_newFixture = 0x0001, + e_locked = 0x0002, + e_clearForces = 0x0004, + }; + + friend class b2Body; + friend class b2ContactManager; + friend class b2Controller; + + void Solve(const b2TimeStep& step); + void SolveTOI(); + void SolveTOI(b2Body* body); + + void DrawJoint(b2Joint* joint); + void DrawShape(b2Fixture* shape, const b2Transform& xf, const b2Color& color); + + b2BlockAllocator m_blockAllocator; + b2StackAllocator m_stackAllocator; + + int32 m_flags; + + b2ContactManager m_contactManager; + + b2Body* m_bodyList; + b2Joint* m_jointList; + + int32 m_bodyCount; + int32 m_jointCount; + + b2Vec2 m_gravity; + bool m_allowSleep; + + b2Body* m_groundBody; + + b2DestructionListener* m_destructionListener; + b2DebugDraw* m_debugDraw; + + // This is used to compute the time step ratio to + // support a variable time step. + float32 m_inv_dt0; + + // This is for debugging the solver. + bool m_warmStarting; + + // This is for debugging the solver. + bool m_continuousPhysics; +}; + +inline b2Body* b2World::GetBodyList() +{ + return m_bodyList; +} + +inline b2Joint* b2World::GetJointList() +{ + return m_jointList; +} + +inline b2Contact* b2World::GetContactList() +{ + return m_contactManager.m_contactList; +} + +inline int32 b2World::GetBodyCount() const +{ + return m_bodyCount; +} + +inline int32 b2World::GetJointCount() const +{ + return m_jointCount; +} + +inline int32 b2World::GetContactCount() const +{ + return m_contactManager.m_contactCount; +} + +inline void b2World::SetGravity(const b2Vec2& gravity) +{ + m_gravity = gravity; +} + +inline b2Vec2 b2World::GetGravity() const +{ + return m_gravity; +} + +inline bool b2World::IsLocked() const +{ + return (m_flags & e_locked) == e_locked; +} + +inline void b2World::SetAutoClearForces(bool flag) +{ + if (flag) + { + m_flags |= e_clearForces; + } + else + { + m_flags &= ~e_clearForces; + } +} + +/// Get the flag that controls automatic clearing of forces after each time step. +inline bool b2World::GetAutoClearForces() const +{ + return (m_flags & e_clearForces) == e_clearForces; +} + +#endif diff --git a/uppsrc/plugin/box2d/b2WorldCallbacks.cpp b/uppsrc/plugin/box2d/b2WorldCallbacks.cpp new file mode 100644 index 000000000..231c13ae3 --- /dev/null +++ b/uppsrc/plugin/box2d/b2WorldCallbacks.cpp @@ -0,0 +1,61 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#include "b2WorldCallbacks.h" +#include "b2Fixture.h" + +// Return true if contact calculations should be performed between these two shapes. +// If you implement your own collision filter you may want to build from this implementation. +bool b2ContactFilter::ShouldCollide(b2Fixture* fixtureA, b2Fixture* fixtureB) +{ + const b2Filter& filterA = fixtureA->GetFilterData(); + const b2Filter& filterB = fixtureB->GetFilterData(); + + if (filterA.groupIndex == filterB.groupIndex && filterA.groupIndex != 0) + { + return filterA.groupIndex > 0; + } + + bool collide = (filterA.maskBits & filterB.categoryBits) != 0 && (filterA.categoryBits & filterB.maskBits) != 0; + return collide; +} + +b2DebugDraw::b2DebugDraw() +{ + m_drawFlags = 0; +} + +void b2DebugDraw::SetFlags(uint32 flags) +{ + m_drawFlags = flags; +} + +uint32 b2DebugDraw::GetFlags() const +{ + return m_drawFlags; +} + +void b2DebugDraw::AppendFlags(uint32 flags) +{ + m_drawFlags |= flags; +} + +void b2DebugDraw::ClearFlags(uint32 flags) +{ + m_drawFlags &= ~flags; +} diff --git a/uppsrc/plugin/box2d/b2WorldCallbacks.h b/uppsrc/plugin/box2d/b2WorldCallbacks.h new file mode 100644 index 000000000..a831a17f1 --- /dev/null +++ b/uppsrc/plugin/box2d/b2WorldCallbacks.h @@ -0,0 +1,217 @@ +/* +* Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com +* +* This software is provided 'as-is', without any express or implied +* warranty. In no event will the authors be held liable for any damages +* arising from the use of this software. +* Permission is granted to anyone to use this software for any purpose, +* including commercial applications, and to alter it and redistribute it +* freely, subject to the following restrictions: +* 1. The origin of this software must not be misrepresented; you must not +* claim that you wrote the original software. If you use this software +* in a product, an acknowledgment in the product documentation would be +* appreciated but is not required. +* 2. Altered source versions must be plainly marked as such, and must not be +* misrepresented as being the original software. +* 3. This notice may not be removed or altered from any source distribution. +*/ + +#ifndef B2_WORLD_CALLBACKS_H +#define B2_WORLD_CALLBACKS_H + +#include "b2Settings.h" + +struct b2Vec2; +struct b2Transform; +class b2Fixture; +class b2Body; +class b2Joint; +class b2Contact; +struct b2ContactPoint; +struct b2ContactResult; +struct b2Manifold; + +/// Joints and fixtures are destroyed when their associated +/// body is destroyed. Implement this listener so that you +/// may nullify references to these joints and shapes. +class b2DestructionListener +{ +public: + virtual ~b2DestructionListener() {} + + /// Called when any joint is about to be destroyed due + /// to the destruction of one of its attached bodies. + virtual void SayGoodbye(b2Joint* joint) = 0; + + /// Called when any fixture is about to be destroyed due + /// to the destruction of its parent body. + virtual void SayGoodbye(b2Fixture* fixture) = 0; +}; + +/// Implement this class to provide collision filtering. In other words, you can implement +/// this class if you want finer control over contact creation. +class b2ContactFilter +{ +public: + virtual ~b2ContactFilter() {} + + /// Return true if contact calculations should be performed between these two shapes. + /// @warning for performance reasons this is only called when the AABBs begin to overlap. + virtual bool ShouldCollide(b2Fixture* fixtureA, b2Fixture* fixtureB); +}; + +/// Contact impulses for reporting. Impulses are used instead of forces because +/// sub-step forces may approach infinity for rigid body collisions. These +/// match up one-to-one with the contact points in b2Manifold. +struct b2ContactImpulse +{ + float32 normalImpulses[b2_maxManifoldPoints]; + float32 tangentImpulses[b2_maxManifoldPoints]; +}; + +/// Implement this class to get contact information. You can use these results for +/// things like sounds and game logic. You can also get contact results by +/// traversing the contact lists after the time step. However, you might miss +/// some contacts because continuous physics leads to sub-stepping. +/// Additionally you may receive multiple callbacks for the same contact in a +/// single time step. +/// You should strive to make your callbacks efficient because there may be +/// many callbacks per time step. +/// @warning You cannot create/destroy Box2D entities inside these callbacks. +class b2ContactListener +{ +public: + virtual ~b2ContactListener() {} + + /// Called when two fixtures begin to touch. + virtual void BeginContact(b2Contact* contact) { B2_NOT_USED(contact); } + + /// Called when two fixtures cease to touch. + virtual void EndContact(b2Contact* contact) { B2_NOT_USED(contact); } + + /// This is called after a contact is updated. This allows you to inspect a + /// contact before it goes to the solver. If you are careful, you can modify the + /// contact manifold (e.g. disable contact). + /// A copy of the old manifold is provided so that you can detect changes. + /// Note: this is called only for awake bodies. + /// Note: this is called even when the number of contact points is zero. + /// Note: this is not called for sensors. + /// Note: if you set the number of contact points to zero, you will not + /// get an EndContact callback. However, you may get a BeginContact callback + /// the next step. + virtual void PreSolve(b2Contact* contact, const b2Manifold* oldManifold) + { + B2_NOT_USED(contact); + B2_NOT_USED(oldManifold); + } + + /// This lets you inspect a contact after the solver is finished. This is useful + /// for inspecting impulses. + /// Note: the contact manifold does not include time of impact impulses, which can be + /// arbitrarily large if the sub-step is small. Hence the impulse is provided explicitly + /// in a separate data structure. + /// Note: this is only called for contacts that are touching, solid, and awake. + virtual void PostSolve(b2Contact* contact, const b2ContactImpulse* impulse) + { + B2_NOT_USED(contact); + B2_NOT_USED(impulse); + } +}; + +/// Callback class for AABB queries. +/// See b2World::Query +class b2QueryCallback +{ +public: + virtual ~b2QueryCallback() {} + + /// Called for each fixture found in the query AABB. + /// @return false to terminate the query. + virtual bool ReportFixture(b2Fixture* fixture) = 0; +}; + +/// Callback class for ray casts. +/// See b2World::RayCast +class b2RayCastCallback +{ +public: + virtual ~b2RayCastCallback() {} + + /// Called for each fixture found in the query. You control how the ray cast + /// proceeds by returning a float: + /// return -1: ignore this fixture and continue + /// return 0: terminate the ray cast + /// return fraction: clip the ray to this point + /// return 1: don't clip the ray and continue + /// @param fixture the fixture hit by the ray + /// @param point the point of initial intersection + /// @param normal the normal vector at the point of intersection + /// @return -1 to filter, 0 to terminate, fraction to clip the ray for + /// closest hit, 1 to continue + virtual float32 ReportFixture( b2Fixture* fixture, const b2Vec2& point, + const b2Vec2& normal, float32 fraction) = 0; +}; + +/// Color for debug drawing. Each value has the range [0,1]. +struct b2Color +{ + b2Color() {} + b2Color(float32 r, float32 g, float32 b) : r(r), g(g), b(b) {} + void Set(float32 ri, float32 gi, float32 bi) { r = ri; g = gi; b = bi; } + float32 r, g, b; +}; + +/// Implement and register this class with a b2World to provide debug drawing of physics +/// entities in your game. +class b2DebugDraw +{ +public: + b2DebugDraw(); + + virtual ~b2DebugDraw() {} + + enum + { + e_shapeBit = 0x0001, ///< draw shapes + e_jointBit = 0x0002, ///< draw joint connections + e_aabbBit = 0x0004, ///< draw axis aligned bounding boxes + e_pairBit = 0x0008, ///< draw broad-phase pairs + e_centerOfMassBit = 0x0010, ///< draw center of mass frame + }; + + /// Set the drawing flags. + void SetFlags(uint32 flags); + + /// Get the drawing flags. + uint32 GetFlags() const; + + /// Append flags to the current flags. + void AppendFlags(uint32 flags); + + /// Clear flags from the current flags. + void ClearFlags(uint32 flags); + + /// Draw a closed polygon provided in CCW order. + virtual void DrawPolygon(const b2Vec2* vertices, int32 vertexCount, const b2Color& color) = 0; + + /// Draw a solid closed polygon provided in CCW order. + virtual void DrawSolidPolygon(const b2Vec2* vertices, int32 vertexCount, const b2Color& color) = 0; + + /// Draw a circle. + virtual void DrawCircle(const b2Vec2& center, float32 radius, const b2Color& color) = 0; + + /// Draw a solid circle. + virtual void DrawSolidCircle(const b2Vec2& center, float32 radius, const b2Vec2& axis, const b2Color& color) = 0; + + /// Draw a line segment. + virtual void DrawSegment(const b2Vec2& p1, const b2Vec2& p2, const b2Color& color) = 0; + + /// Draw a transform. Choose your own length scale. + /// @param xf a transform. + virtual void DrawTransform(const b2Transform& xf) = 0; + +protected: + uint32 m_drawFlags; +}; + +#endif diff --git a/uppsrc/plugin/box2d/box2d.upp b/uppsrc/plugin/box2d/box2d.upp new file mode 100644 index 000000000..0230494d4 --- /dev/null +++ b/uppsrc/plugin/box2d/box2d.upp @@ -0,0 +1,83 @@ +description "Box2D\3770,128,128"; + +optimize_speed; + +file + Box2D.h, + Collision readonly separator, + b2BroadPhase.cpp, + b2BroadPhase.h, + b2CollideCircle.cpp, + b2CollidePolygon.cpp, + b2Collision.cpp, + b2Collision.h, + b2Distance.cpp, + b2Distance.h, + b2DynamicTree.cpp, + b2DynamicTree.h, + b2TimeOfImpact.cpp, + b2TimeOfImpact.h, + Shapes readonly separator, + b2CircleShape.cpp, + b2CircleShape.h, + b2PolygonShape.cpp, + b2PolygonShape.h, + b2Shape.h, + Common readonly separator, + b2BlockAllocator.cpp, + b2BlockAllocator.h, + b2Math.cpp, + b2Math.h, + b2Settings.cpp, + b2Settings.h, + b2StackAllocator.cpp, + b2StackAllocator.h, + Dynamics readonly separator, + b2Body.cpp, + b2Body.h, + b2ContactManager.cpp, + b2ContactManager.h, + b2Fixture.cpp, + b2Fixture.h, + b2Island.cpp, + b2Island.h, + b2TimeStep.h, + b2World.cpp, + b2World.h, + b2WorldCallbacks.cpp, + b2WorldCallbacks.h, + Contacts readonly separator, + b2CircleContact.cpp, + b2CircleContact.h, + b2Contact.cpp, + b2Contact.h, + b2ContactSolver.cpp, + b2ContactSolver.h, + b2PolygonAndCircleContact.cpp, + b2PolygonAndCircleContact.h, + b2PolygonContact.cpp, + b2PolygonContact.h, + b2TOISolver.cpp, + b2TOISolver.h, + Joints readonly separator, + b2DistanceJoint.cpp, + b2DistanceJoint.h, + b2FrictionJoint.cpp, + b2FrictionJoint.h, + b2GearJoint.cpp, + b2GearJoint.h, + b2Joint.cpp, + b2Joint.h, + b2LineJoint.cpp, + b2LineJoint.h, + b2MouseJoint.cpp, + b2MouseJoint.h, + b2PrismaticJoint.cpp, + b2PrismaticJoint.h, + b2PulleyJoint.cpp, + b2PulleyJoint.h, + b2RevoluteJoint.cpp, + b2RevoluteJoint.h, + b2WeldJoint.cpp, + b2WeldJoint.h; + diff --git a/uppsrc/plugin/box2d/fixincludes.pl b/uppsrc/plugin/box2d/fixincludes.pl new file mode 100644 index 000000000..f1a29fecd --- /dev/null +++ b/uppsrc/plugin/box2d/fixincludes.pl @@ -0,0 +1,29 @@ +@files = glob("*.cpp *.h"); + +foreach $f (@files) +{ + print("Processing $f\n"); + + open(IN, "<$f"); + + @file = ; + + close(IN); + + open(IN, ">$f"); + + foreach $line (@file) { + if($line =~ /(\)/) { + $oi = $1; + if($oi =~ /([\w\d\_]+\.h)/) + { + $ni = "\"$1\""; + $line =~ s/$oi/$ni/g; + } + print "$line"; + } + + print IN $line; + } + close IN; +} \ No newline at end of file diff --git a/uppsrc/plugin/box2d/init b/uppsrc/plugin/box2d/init new file mode 100644 index 000000000..2ea292025 --- /dev/null +++ b/uppsrc/plugin/box2d/init @@ -0,0 +1,3 @@ +#ifndef _plugin_box2d_icpp_init_stub +#define _plugin_box2d_icpp_init_stub +#endif