ultimatepp/bazaar/plugin/geotiff/libgeotiff/ogr/ogrlinearring.cpp
cxl b67920c1ca bazaar: plugin/geotiff
git-svn-id: svn://ultimatepp.org/upp/trunk@7587 f0d560ea-af0d-0410-9eb7-867de7ffcac7
2014-08-12 18:56:26 +00:00

558 lines
18 KiB
C++

/******************************************************************************
* $Id: ogrlinearring.cpp 15517 2008-10-11 18:34:03Z rouault $
*
* Project: OpenGIS Simple Features Reference Implementation
* Purpose: The OGRLinearRing geometry class.
* Author: Frank Warmerdam, warmerdam@pobox.com
*
******************************************************************************
* Copyright (c) 1999, Frank Warmerdam
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
****************************************************************************/
#include "ogr_geometry.h"
#include "ogr_p.h"
CPL_CVSID("$Id: ogrlinearring.cpp 15517 2008-10-11 18:34:03Z rouault $");
/************************************************************************/
/* OGRLinearRing() */
/************************************************************************/
OGRLinearRing::OGRLinearRing()
{
}
/************************************************************************/
/* ~OGRLinearRing() */
/************************************************************************/
OGRLinearRing::~OGRLinearRing()
{
}
/************************************************************************/
/* OGRLinearRing() */
/************************************************************************/
OGRLinearRing::OGRLinearRing( OGRLinearRing * poSrcRing )
{
if( poSrcRing == NULL )
{
CPLDebug( "OGR", "OGRLinearRing::OGRLinearRing(OGRLinearRing*poSrcRing) - passed in ring is NULL!" );
return;
}
setNumPoints( poSrcRing->getNumPoints() );
memcpy( paoPoints, poSrcRing->paoPoints,
sizeof(OGRRawPoint) * getNumPoints() );
if( poSrcRing->padfZ )
{
Make3D();
memcpy( padfZ, poSrcRing->padfZ, sizeof(double) * getNumPoints() );
}
}
/************************************************************************/
/* getGeometryName() */
/************************************************************************/
const char * OGRLinearRing::getGeometryName() const
{
return "LINEARRING";
}
/************************************************************************/
/* WkbSize() */
/* */
/* Disable this method. */
/************************************************************************/
int OGRLinearRing::WkbSize() const
{
return 0;
}
/************************************************************************/
/* importFromWkb() */
/* */
/* Disable method for this class. */
/************************************************************************/
OGRErr OGRLinearRing::importFromWkb( unsigned char *pabyData, int nSize )
{
(void) pabyData;
(void) nSize;
return OGRERR_UNSUPPORTED_OPERATION;
}
/************************************************************************/
/* exportToWkb() */
/* */
/* Disable method for this class. */
/************************************************************************/
OGRErr OGRLinearRing::exportToWkb( OGRwkbByteOrder eByteOrder,
unsigned char * pabyData ) const
{
(void) eByteOrder;
(void) pabyData;
return OGRERR_UNSUPPORTED_OPERATION;
}
/************************************************************************/
/* _importFromWkb() */
/* */
/* Helper method for OGRPolygon. NOT A NORMAL importFromWkb() */
/* method! */
/************************************************************************/
OGRErr OGRLinearRing::_importFromWkb( OGRwkbByteOrder eByteOrder, int b3D,
unsigned char * pabyData,
int nBytesAvailable )
{
if( nBytesAvailable < 4 && nBytesAvailable != -1 )
return OGRERR_NOT_ENOUGH_DATA;
/* -------------------------------------------------------------------- */
/* Get the vertex count. */
/* -------------------------------------------------------------------- */
int nNewNumPoints;
memcpy( &nNewNumPoints, pabyData, 4 );
if( OGR_SWAP( eByteOrder ) )
nNewNumPoints = CPL_SWAP32(nNewNumPoints);
/* Check if the wkb stream buffer is big enough to store
* fetched number of points.
* 16 or 24 - size of point structure
*/
int nPointSize = (b3D ? 24 : 16);
int nBufferMinSize = nPointSize * nNewNumPoints;
if( nBufferMinSize > nBytesAvailable && nBytesAvailable > 0 )
{
CPLError( CE_Failure, CPLE_AppDefined,
"Length of input WKB is too small" );
return OGRERR_NOT_ENOUGH_DATA;
}
/* (Re)Allocation of paoPoints buffer. */
setNumPoints( nNewNumPoints );
if( b3D )
Make3D();
else
Make2D();
/* -------------------------------------------------------------------- */
/* Get the vertices */
/* -------------------------------------------------------------------- */
int i = 0;
int nBytesToCopy = 0;
if( !b3D )
{
nBytesToCopy = 16 * nPointCount;
if( nBytesToCopy > nBytesAvailable && nBytesAvailable > 0 )
{
CPLError( CE_Failure, CPLE_AppDefined,
"WKB buffer with OGRLinearRing points is too small! \
\n\tWKB stream may be corrupted or it is EWKB stream which is not supported");
return OGRERR_NOT_ENOUGH_DATA;
}
memcpy( paoPoints, pabyData + 4, nBytesToCopy );
}
else
{
for( int i = 0; i < nPointCount; i++ )
{
nBytesToCopy = 24;
if( nBytesToCopy > nBytesAvailable && nBytesAvailable > 0 )
{
CPLError( CE_Failure, CPLE_AppDefined,
"WKB buffer with OGRLinearRing points is too small! \
\n\tWKB stream may be corrupted or it is EWKB stream which is not supported");
return OGRERR_NOT_ENOUGH_DATA;
}
if ( nBytesAvailable > 0 )
nBytesAvailable -= nBytesToCopy;
memcpy( &(paoPoints[i].x), pabyData + 4 + 24 * i, 8 );
memcpy( &(paoPoints[i].y), pabyData + 4 + 24 * i + 8, 8 );
memcpy( padfZ + i, pabyData + 4 + 24 * i + 16, 8 );
}
}
/* -------------------------------------------------------------------- */
/* Byte swap if needed. */
/* -------------------------------------------------------------------- */
if( OGR_SWAP( eByteOrder ) )
{
for( i = 0; i < nPointCount; i++ )
{
CPL_SWAPDOUBLE( &(paoPoints[i].x) );
CPL_SWAPDOUBLE( &(paoPoints[i].y) );
if( b3D )
{
CPL_SWAPDOUBLE( padfZ + i );
}
}
}
return OGRERR_NONE;
}
/************************************************************************/
/* _exportToWkb() */
/* */
/* Helper method for OGRPolygon. THIS IS NOT THE NORMAL */
/* exportToWkb() METHOD! */
/************************************************************************/
OGRErr OGRLinearRing::_exportToWkb( OGRwkbByteOrder eByteOrder, int b3D,
unsigned char * pabyData ) const
{
int i, nWords;
/* -------------------------------------------------------------------- */
/* Copy in the raw data. */
/* -------------------------------------------------------------------- */
memcpy( pabyData, &nPointCount, 4 );
/* -------------------------------------------------------------------- */
/* Copy in the raw data. */
/* -------------------------------------------------------------------- */
if( b3D )
{
nWords = 3 * nPointCount;
for( i = 0; i < nPointCount; i++ )
{
memcpy( pabyData+4+i*24, &(paoPoints[i].x), 8 );
memcpy( pabyData+4+i*24+8, &(paoPoints[i].y), 8 );
if( padfZ == NULL )
memset( pabyData+4+i*24+16, 0, 8 );
else
memcpy( pabyData+4+i*24+16, padfZ + i, 8 );
}
}
else
{
nWords = 2 * nPointCount;
memcpy( pabyData+4, paoPoints, 16 * nPointCount );
}
/* -------------------------------------------------------------------- */
/* Swap if needed. */
/* -------------------------------------------------------------------- */
if( OGR_SWAP( eByteOrder ) )
{
int nCount;
nCount = CPL_SWAP32( nPointCount );
memcpy( pabyData, &nCount, 4 );
for( i = 0; i < nWords; i++ )
{
CPL_SWAPDOUBLE( pabyData + 4 + 8 * i );
}
}
return OGRERR_NONE;
}
/************************************************************************/
/* _WkbSize() */
/* */
/* Helper method for OGRPolygon. NOT THE NORMAL WkbSize() METHOD! */
/************************************************************************/
int OGRLinearRing::_WkbSize( int b3D ) const
{
if( b3D )
return 4 + 24 * nPointCount;
else
return 4 + 16 * nPointCount;
}
/************************************************************************/
/* clone() */
/* */
/* We override the OGRCurve clone() to ensure that we get the */
/* correct virtual table. */
/************************************************************************/
OGRGeometry *OGRLinearRing::clone() const
{
OGRLinearRing *poNewLinearRing;
poNewLinearRing = new OGRLinearRing();
poNewLinearRing->assignSpatialReference( getSpatialReference() );
poNewLinearRing->setPoints( nPointCount, paoPoints, padfZ );
return poNewLinearRing;
}
/************************************************************************/
/* isClockwise() */
/************************************************************************/
/**
* Returns TRUE if the ring has clockwise winding.
*
* @return TRUE if clockwise otherwise FALSE.
*/
int OGRLinearRing::isClockwise() const
{
double dfSum = 0.0;
for( int iVert = 0; iVert < nPointCount-1; iVert++ )
{
dfSum += paoPoints[iVert].x * paoPoints[iVert+1].y
- paoPoints[iVert].y * paoPoints[iVert+1].x;
}
dfSum += paoPoints[nPointCount-1].x * paoPoints[0].y
- paoPoints[nPointCount-1].y * paoPoints[0].x;
return dfSum < 0.0;
}
/************************************************************************/
/* reverseWindingOrder() */
/************************************************************************/
void OGRLinearRing::reverseWindingOrder()
{
int pos = 0;
OGRPoint tempPoint;
for( int i = 0; i < nPointCount / 2; i++ )
{
getPoint( i, &tempPoint );
pos = nPointCount - i - 1;
setPoint( i, getX(pos), getY(pos), getZ(pos) );
setPoint( pos, tempPoint.getX(), tempPoint.getY(), tempPoint.getZ() );
}
}
/************************************************************************/
/* closeRing() */
/************************************************************************/
void OGRLinearRing::closeRings()
{
if( nPointCount < 2 )
return;
if( getX(0) != getX(nPointCount-1)
|| getY(0) != getY(nPointCount-1)
|| getZ(0) != getZ(nPointCount-1) )
{
/* Avoid implicit change of coordinate dimensionality
* if z=0.0 and dim=2
*/
if( getCoordinateDimension() == 2 )
addPoint( getX(0), getY(0) );
else
addPoint( getX(0), getY(0), getZ(0) );
}
}
/************************************************************************/
/* get_Area() */
/************************************************************************/
/**
* Compute area of ring.
*
* The area is computed according to Green's Theorem:
*
* Area is "Sum(x(i)*y(i+1) - x(i+1)*y(i))/2" for i = 0 to pointCount-1,
* assuming the last point is a duplicate of the first.
*
* @return computed area.
*/
double OGRLinearRing::get_Area() const
{
double dfAreaSum = 0.0;
int i;
for( i = 0; i < nPointCount-1; i++ )
{
dfAreaSum += 0.5 * ( paoPoints[i].x * paoPoints[i+1].y
- paoPoints[i+1].x * paoPoints[i].y );
}
dfAreaSum += 0.5 * ( paoPoints[nPointCount-1].x * paoPoints[0].y
- paoPoints[0].x * paoPoints[nPointCount-1].y );
return fabs(dfAreaSum);
}
/************************************************************************/
/* isPointInRing() */
/************************************************************************/
OGRBoolean OGRLinearRing::isPointInRing(const OGRPoint* poPoint, int bTestEnvelope) const
{
if ( NULL == poPoint )
{
CPLDebug( "OGR", "OGRLinearRing::isPointInRing(const OGRPoint* poPoint) - passed point is NULL!" );
return 0;
}
const int iNumPoints = getNumPoints();
// Simple validation
if ( iNumPoints < 4 )
return 0;
const double dfTestX = poPoint->getX();
const double dfTestY = poPoint->getY();
// Fast test if point is inside extent of the ring
if (bTestEnvelope)
{
OGREnvelope extent;
getEnvelope(&extent);
if ( !( dfTestX >= extent.MinX && dfTestX <= extent.MaxX
&& dfTestY >= extent.MinY && dfTestY <= extent.MaxY ) )
{
return 0;
}
}
// For every point p in ring,
// test if ray starting from given point crosses segment (p - 1, p)
int iNumCrossings = 0;
for ( int iPoint = 1; iPoint < iNumPoints; iPoint++ )
{
const int iPointPrev = iPoint - 1;
const double x1 = getX(iPoint) - dfTestX;
const double y1 = getY(iPoint) - dfTestY;
const double x2 = getX(iPointPrev) - dfTestX;
const double y2 = getY(iPointPrev) - dfTestY;
if( ( ( y1 > 0 ) && ( y2 <= 0 ) ) || ( ( y2 > 0 ) && ( y1 <= 0 ) ) )
{
// Check if ray intersects with segment of the ring
const double dfIntersection = ( x1 * y2 - x2 * y1 ) / (y2 - y1);
if ( 0.0 < dfIntersection )
{
// Count intersections
iNumCrossings++;
}
}
}
// If iNumCrossings number is even, given point is outside the ring,
// when the crossings number is odd, the point is inside the ring.
return ( ( iNumCrossings % 2 ) == 1 ? 1 : 0 );
}
/************************************************************************/
/* isPointOnRingBoundary() */
/************************************************************************/
OGRBoolean OGRLinearRing::isPointOnRingBoundary(const OGRPoint* poPoint, int bTestEnvelope) const
{
if ( NULL == poPoint )
{
CPLDebug( "OGR", "OGRLinearRing::isPointOnRingBoundary(const OGRPoint* poPoint) - passed point is NULL!" );
return 0;
}
const int iNumPoints = getNumPoints();
// Simple validation
if ( iNumPoints < 4 )
return 0;
const double dfTestX = poPoint->getX();
const double dfTestY = poPoint->getY();
// Fast test if point is inside extent of the ring
OGREnvelope extent;
getEnvelope(&extent);
if ( !( dfTestX >= extent.MinX && dfTestX <= extent.MaxX
&& dfTestY >= extent.MinY && dfTestY <= extent.MaxY ) )
{
return 0;
}
for ( int iPoint = 1; iPoint < iNumPoints; iPoint++ )
{
const int iPointPrev = iPoint - 1;
const double x1 = getX(iPoint) - dfTestX;
const double y1 = getY(iPoint) - dfTestY;
const double x2 = getX(iPointPrev) - dfTestX;
const double y2 = getY(iPointPrev) - dfTestY;
/* If iPoint and iPointPrev are the same, go on */
if (x1 == x2 && y1 == y2)
{
continue;
}
/* If the point is on the segment, return immediatly */
/* FIXME? If the test point is not exactly identical to one of */
/* the vertices of the ring, but somewhere on a segment, there's */
/* little chance that we get 0. So that should be tested against some epsilon */
if ( x1 * y2 - x2 * y1 == 0 )
{
return 1;
}
}
return 0;
}