Refactoring Rasterizer

git-svn-id: svn://ultimatepp.org/upp/trunk@820 f0d560ea-af0d-0410-9eb7-867de7ffcac7
This commit is contained in:
cxl 2009-01-28 19:06:20 +00:00
parent 3cf347c47e
commit d2d643e416
6 changed files with 546 additions and 0 deletions

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#include "ScanLine.h"
Rasterizer::Rasterizer(int cy)
{
min_y = INT_MAX;
max_y = INT_MIN;
finish = true;
current.Init();
cell.Alloc(cy);
}
inline void Rasterizer::AddCurrent()
{
if(current.area | current.cover)
cell[current_y].Add(current);
}
inline void Rasterizer::SetCurrent(int x, int y)
{
if(current.x != x || current_y != y) {
AddCurrent();
current.x = x;
current_y = y;
current.cover = current.area = 0;
}
}
inline void Rasterizer::RenderHLine(int ey, int x1, int y1, int x2, int y2)
{
int ex1 = x1 >> 8;
int ex2 = x2 >> 8;
int fx1 = x1 & 255;
int fx2 = x2 & 255;
if(y1 == y2) {
SetCurrent(ex2, ey);
return;
}
if(ex1 == ex2) {
int delta = y2 - y1;
current.cover += delta;
current.area += (fx1 + fx2) * delta;
return;
}
int p = (256 - fx1) * (y2 - y1);
int first = 256;
int incr = 1;
int dx = x2 - x1;
if(dx < 0) {
p = fx1 * (y2 - y1);
first = 0;
incr = -1;
dx = -dx;
}
int delta = p / dx;
int mod = p % dx;
if(mod < 0) {
delta--;
mod += dx;
}
current.cover += delta;
current.area += (fx1 + first) * delta;
ex1 += incr;
SetCurrent(ex1, ey);
y1 += delta;
if(ex1 != ex2) {
p = (y2 - y1 + delta) << 8;
int lift = p / dx;
int rem = p % dx;
if (rem < 0) {
lift--;
rem += dx;
}
mod -= dx;
while(ex1 != ex2) {
delta = lift;
mod += rem;
if(mod >= 0) {
mod -= dx;
delta++;
}
current.cover += delta;
current.area += delta << 8;
y1 += delta;
ex1 += incr;
SetCurrent(ex1, ey);
}
}
delta = y2 - y1;
current.cover += delta;
current.area += (fx2 + 256 - first) * delta;
}
void Rasterizer::Line(int x1, int y1, int x2, int y2)
{
enum dx_limit_e { dx_limit = 16384 << 8 };
int dx = x2 - x1;
if(dx >= dx_limit || dx <= -dx_limit) {
int cx = (x1 + x2) >> 1;
int cy = (y1 + y2) >> 1;
Line(x1, y1, cx, cy);
Line(cx, cy, x2, y2);
return;
}
int dy = y2 - y1;
int ex1 = x1 >> 8;
int ex2 = x2 >> 8;
int ey1 = y1 >> 8;
int ey2 = y2 >> 8;
int fy1 = y1 & 255;
int fy2 = y2 & 255;
int x_from, x_to;
int p, rem, mod, lift, delta, first, incr;
if(ey1 < min_y) min_y = ey1;
if(ey1 > max_y) max_y = ey1;
if(ey2 < min_y) min_y = ey2;
if(ey2 > max_y) max_y = ey2;
SetCurrent(ex1, ey1);
if(ey1 == ey2) {
RenderHLine(ey1, x1, fy1, x2, fy2);
return;
}
incr = 1;
if(dx == 0) {
int ex = x1 >> 8;
int two_fx = (x1 - (ex << 8)) << 1;
int area;
first = 256;
if(dy < 0) {
first = 0;
incr = -1;
}
x_from = x1;
delta = first - fy1;
current.cover += delta;
current.area += two_fx * delta;
ey1 += incr;
SetCurrent(ex, ey1);
delta = first + first - 256;
area = two_fx * delta;
while(ey1 != ey2) {
current.cover = delta;
current.area = area;
ey1 += incr;
SetCurrent(ex, ey1);
}
delta = fy2 - 256 + first;
current.cover += delta;
current.area += two_fx * delta;
return;
}
p = (256 - fy1) * dx;
first = 256;
if(dy < 0) {
p = fy1 * dx;
first = 0;
incr = -1;
dy = -dy;
}
delta = p / dy;
mod = p % dy;
if(mod < 0) {
delta--;
mod += dy;
}
x_from = x1 + delta;
RenderHLine(ey1, x1, fy1, x_from, first);
ey1 += incr;
SetCurrent(x_from >> 8, ey1);
if(ey1 != ey2) {
p = dx << 8;
lift = p / dy;
rem = p % dy;
if(rem < 0) {
lift--;
rem += dy;
}
mod -= dy;
while(ey1 != ey2) {
delta = lift;
mod += rem;
if(mod >= 0) {
mod -= dy;
delta++;
}
x_to = x_from + delta;
RenderHLine(ey1, x_from, 256 - first, x_to, first);
x_from = x_to;
ey1 += incr;
SetCurrent(x_from >> 8, ey1);
}
}
RenderHLine(ey1, x_from, 256 - first, x2, fy2);
}
inline unsigned Alpha(int area)
{
int cover = area >> (2 * 8 + 1 - 8);
if(cover < 0) cover = -cover;
/* if(evenodd) {
cover &= 511;
if(cover > 256)
cover = 512 - cover;
}*/
if(cover > 255) cover = 255;
return (cover + 1) / 2;
}
ScanLine Rasterizer::Get(int y)
{
if(finish) {
AddCurrent();
finish = false;
}
ScanLine r;
r.len = 0;
r.x = 0;
Vector<Cell>& cl = cell[y];
Sort(cl);
if(y < min_y || y > max_y || cl.GetCount() == 0) return r;
const Cell *c = cl;
const Cell *e = cl.End();
r.x = c->x;
int cover = 0;
while(c < e) {
int x = c->x;
int area = c->area;
cover += c->cover;
c++;
while(c < e && c->x == x) {
area += c->area;
cover += c->cover;
c++;
}
if(area)
r.data.Cat(Alpha((cover << (8 + 1)) - area));
else
r.data.Cat(0);
r.len++;
x++;
if(c < e && c->x > x) {
byte val = Alpha(cover << (8 + 1));
int n = c->x - x;
r.len += n;
while(n > 0) {
int q = min(n, 127);
r.data.Cat(q + 128);
r.data.Cat(val);
n -= q;
}
}
}
return r;
}

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#include "ScanLine.h"
ScanLine And0(const ScanLine& a, const ScanLine& b)
{
ScanLine r;
r.len = 0;
r.x = b.x;
byte aval = 0;
int acount = 0;
byte bval = 0;
int ai = 0;
int bi = 0;
int bcount = b.x - a.x;
while(bcount) {
if(ai >= a.data.GetCount())
return r;
aval = a.data[ai++];
if(aval > 128) {
acount = aval - 128;
aval = a.data[ai++];
int n = min(acount, bcount);
acount -= n;
bcount -= n;
}
else
bcount--;
}
while(ai < a.data.GetCount() && bi < b.data.GetCount()) {
if(acount == 0) {
aval = a.data[ai++];
if(aval > 128) {
acount = aval - 128;
aval = a.data[ai++];
}
}
if(bcount == 0) {
bval = b.data[bi++];
if(bval > 128) {
bcount = bval - 128;
bval = b.data[bi++];
}
}
if(acount && bcount) {
int l = min(acount, bcount);
acount -= l;
bcount -= l;
r.len += l;
while(l) {
int n = min(l, 127);
r.data.Cat(n + 128);
r.data.Cat((aval * bval) >> 7);
l -= n;
}
}
else {
r.data.Cat((aval * bval) >> 7);
r.len++;
if(acount) acount--;
if(bcount) bcount--;
}
}
return r;
}
ScanLine And(const ScanLine& a, const ScanLine& b)
{
return a.x < b.x ? And0(a, b) : And0(b, a);
}
ScanLine Pack(int x, const byte *data, int len)
{
ScanLine r;
int i = 0;
r.x = x;
r.len = 0;
while(i < len) {
int n = i;
byte val = data[i++];
while(i < len && data[i] == val)
i++;
n = i - n;
if(n > 1) {
r.len += n;
while(n) {
int q = min(n, 127);
r.data.Cat(q + 128);
r.data.Cat(val);
n -= q;
}
}
else {
r.data.Cat(val);
r.len++;
}
}
return r;
}
String ScanLine::ToString() const
{
String s;
s << "x = " << x << ", len = " << len << ": ";
for(int i = 0; i < data.GetCount(); i++) {
byte val = data[i];
if(val > 128) {
int n = val - 128;
val = data[++i];
while(n--)
s << (int)val << ", ";
}
else
s << (int)val << ", ";
}
s << "datalen: " << data.GetCount();
return s;
}
void Apply(RGBA *t, int len, const RGBA& color, const ScanLine& s)
{
t += s.x;
len -= s.x;
int si = 0;
while(len >= 0 && si < s.data.GetLength()) {
byte val = s.data[si++];
if(val > 128) {
int n = min(len, val - 128);
val = s.data[si++];
while(n--)
AlphaBlendCover7(*t++, color, val);
len -= n;
}
else
AlphaBlendCover7(*t++, color, val);
}
}

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#ifndef _ScanLine_ScanLine_h_
#define _ScanLine_ScanLine_h_
#include <CtrlLib/CtrlLib.h>
using namespace Upp;
inline RGBA Mul7(const RGBA& s, int mul)
{
RGBA t;
t.r = (mul * s.r) >> 7;
t.g = (mul * s.g) >> 7;
t.b = (mul * s.b) >> 7;
t.a = (mul * s.a) >> 7;
return t;
}
inline void AlphaBlend(RGBA& t, const RGBA& c)
{
int alpha = 256 - (c.a + (c.a >> 7));
t.r = c.r + (alpha * t.r >> 8);
t.g = c.g + (alpha * t.g >> 8);
t.b = c.b + (alpha * t.b >> 8);
t.a = c.a + (alpha * t.a >> 8);
}
inline void AlphaBlendCover7(RGBA& t, const RGBA& c, byte cover)
{
AlphaBlend(t, Mul7(c, cover));
}
struct ScanLine {
int x, len;
String data;
String ToString() const;
};
void Apply(RGBA *t, int len, const RGBA& color, const ScanLine& s);
ScanLine And(const ScanLine& a, const ScanLine& b);
ScanLine Pack(int x, const byte *data, int len);
class Rasterizer {
struct Cell : Moveable<Cell> {
int x;
int cover;
int area;
void Init() { x = 0x7FFFFFFF; cover = area = 0; }
bool operator<(const Cell& b) const { return x < b.x; }
};
struct SortedY {
unsigned start;
unsigned num;
};
Buffer< Vector<Cell> > cell;
int current_y;
Cell current;
int min_y;
int max_y;
bool finish;
void AddCurrent();
void SetCurrent(int x, int y);
void RenderHLine(int ey, int x1, int y1, int x2, int y2);
public:
void Line(int x1, int y1, int x2, int y2);
int MinY() const { return min_y; }
int MaxY() const { return max_y; }
ScanLine Get(int y);
Rasterizer(int cy);
};
#endif

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uses
Core,
CtrlLib;
file
ScanLine.h,
ScanLine.cpp,
Rasterizer.cpp,
main.cpp;
mainconfig
"" = "GUI";

5
uppdev/ScanLine/init Normal file
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#ifndef _ScanLine_icpp_init_stub
#define _ScanLine_icpp_init_stub
#include "Core/init"
#include "CtrlLib/init"
#endif

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uppdev/ScanLine/main.cpp Normal file
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#include "ScanLine.h"
struct App : TopWindow {
virtual void Paint(Draw& w) {
ScanLine a, b;
static byte line1[] = { 1, 50, 100, 128, 128, 128, 128, 128, 100, 50, 1 };
a = Pack(0, line1, __countof(line1));
ImageBuffer ib(400, 400);
Fill(~ib, White(), ib.GetLength());
Apply(ib[20], 100, Black(), a);
a.x = 10;
Apply(ib[30], 100, Blue(), a);
for(int i = 0; i < 20; i++) {
b = Pack(i, line1, __countof(line1));
Apply(ib[50 + 2 * i], 100, Black(), And(a, b));
}
Rasterizer r(400);
r.Line(100 * 256, 100 * 256, 300 * 256, 100 * 256);
r.Line(300 * 256, 100 * 256, 200 * 256, 300 * 256);
r.Line(200 * 256, 300 * 256, 100 * 256, 100 * 256);
for(int y = r.MinY(); y <= r.MaxY(); y++) {
ScanLine sl = r.Get(y);
DUMP(sl);
Apply(ib[y], 400, Black(), sl);
}
w.DrawRect(GetSize(), White());
w.DrawImage(0, 0, ib);
}
};
GUI_APP_MAIN {
App().Run();
ScanLine a, b, c;
static byte line1[] = { 1, 50, 100, 128, 128, 128, 128, 128, 100, 50, 1 };
a = Pack(0, line1, __countof(line1));
DUMP(a);
for(int i = 0; i < 16; i++) {
b = Pack(i, line1, __countof(line1));
DUMP(b);
DUMP(And(a, b));
DUMP(And(b, a));
}
#ifndef _DEBUG
int x = 0;
b = Pack(3, line1, __countof(line1));
for(int i = 0; i < 10000000; i++) {
RTIMING("And");
x += And(a, b).x;
}
#endif
}