ultimatepp/bazaar/plugin/gdal/ogr/ogrlinearring.cpp
cxl 23ff1e7e82 .gdal moved to bazaar
git-svn-id: svn://ultimatepp.org/upp/trunk@9273 f0d560ea-af0d-0410-9eb7-867de7ffcac7
2015-12-07 13:36:24 +00:00

632 lines
21 KiB
C++

/******************************************************************************
* $Id: ogrlinearring.cpp 27959 2014-11-14 18:29:21Z rouault $
*
* Project: OpenGIS Simple Features Reference Implementation
* Purpose: The OGRLinearRing geometry class.
* Author: Frank Warmerdam, warmerdam@pobox.com
*
******************************************************************************
* Copyright (c) 1999, Frank Warmerdam
* Copyright (c) 2008-2014, Even Rouault <even dot rouault at mines-paris dot org>
*
* 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 27959 2014-11-14 18:29:21Z 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(), FALSE );
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( CPL_UNUSED unsigned char *pabyData,
CPL_UNUSED int nSize,
CPL_UNUSED OGRwkbVariant eWkbVariant )
{
return OGRERR_UNSUPPORTED_OPERATION;
}
/************************************************************************/
/* exportToWkb() */
/* */
/* Disable method for this class. */
/************************************************************************/
OGRErr OGRLinearRing::exportToWkb( CPL_UNUSED OGRwkbByteOrder eByteOrder,
CPL_UNUSED unsigned char * pabyData,
CPL_UNUSED OGRwkbVariant eWkbVariant ) const
{
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);
if (nNewNumPoints < 0 || nNewNumPoints > INT_MAX / nPointSize)
return OGRERR_CORRUPT_DATA;
int nBufferMinSize = nPointSize * nNewNumPoints;
if( nBytesAvailable != -1 && nBufferMinSize > nBytesAvailable - 4 )
{
CPLError( CE_Failure, CPLE_AppDefined,
"Length of input WKB is too small" );
return OGRERR_NOT_ENOUGH_DATA;
}
/* (Re)Allocation of paoPoints buffer. */
setNumPoints( nNewNumPoints, FALSE );
if( b3D )
Make3D();
else
Make2D();
/* -------------------------------------------------------------------- */
/* Get the vertices */
/* -------------------------------------------------------------------- */
int i = 0;
if( !b3D )
{
memcpy( paoPoints, pabyData + 4, 16 * nPointCount );
}
else
{
for( int i = 0; i < nPointCount; i++ )
{
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;
}
/************************************************************************/
/* epsilonEqual() */
/************************************************************************/
static const double EPSILON = 1E-5;
static inline bool epsilonEqual(double a, double b, double eps)
{
return (::fabs(a - b) < eps);
}
/************************************************************************/
/* isClockwise() */
/************************************************************************/
/**
* \brief Returns TRUE if the ring has clockwise winding (or less than 2 points)
*
* @return TRUE if clockwise otherwise FALSE.
*/
int OGRLinearRing::isClockwise() const
{
int i, v, next;
double dx0, dy0, dx1, dy1, crossproduct;
int bUseFallback = FALSE;
if( nPointCount < 2 )
return TRUE;
/* Find the lowest rightmost vertex */
v = 0;
for ( i = 1; i < nPointCount - 1; i++ )
{
/* => v < end */
if ( paoPoints[i].y< paoPoints[v].y ||
( paoPoints[i].y== paoPoints[v].y &&
paoPoints[i].x > paoPoints[v].x ) )
{
v = i;
bUseFallback = FALSE;
}
else if ( paoPoints[i].y == paoPoints[v].y &&
paoPoints[i].x == paoPoints[v].x )
{
/* Two vertex with same coordinates are the lowest rightmost */
/* vertex! We cannot use that point as the pivot (#5342) */
bUseFallback = TRUE;
}
}
/* previous */
next = v - 1;
if ( next < 0 )
{
next = nPointCount - 1 - 1;
}
if( epsilonEqual(paoPoints[next].x, paoPoints[v].x, EPSILON) &&
epsilonEqual(paoPoints[next].y, paoPoints[v].y, EPSILON) )
{
/* Don't try to be too clever by retrying with a next point */
/* This can lead to false results as in the case of #3356 */
bUseFallback = TRUE;
}
dx0 = paoPoints[next].x - paoPoints[v].x;
dy0 = paoPoints[next].y - paoPoints[v].y;
/* following */
next = v + 1;
if ( next >= nPointCount - 1 )
{
next = 0;
}
if( epsilonEqual(paoPoints[next].x, paoPoints[v].x, EPSILON) &&
epsilonEqual(paoPoints[next].y, paoPoints[v].y, EPSILON) )
{
/* Don't try to be too clever by retrying with a next point */
/* This can lead to false results as in the case of #3356 */
bUseFallback = TRUE;
}
dx1 = paoPoints[next].x - paoPoints[v].x;
dy1 = paoPoints[next].y - paoPoints[v].y;
crossproduct = dx1 * dy0 - dx0 * dy1;
if (!bUseFallback)
{
if ( crossproduct > 0 ) /* CCW */
return FALSE;
else if ( crossproduct < 0 ) /* CW */
return TRUE;
}
/* ok, this is a degenerate case : the extent of the polygon is less than EPSILON */
/* or 2 nearly identical points were found */
/* Try with Green Formula as a fallback, but this is not a guarantee */
/* as we'll probably be affected by numerical instabilities */
double dfSum = paoPoints[0].x * (paoPoints[1].y - paoPoints[nPointCount-1].y);
for (i=1; i<nPointCount-1; i++) {
dfSum += paoPoints[i].x * (paoPoints[i+1].y - paoPoints[i-1].y);
}
dfSum += paoPoints[nPointCount-1].x * (paoPoints[0].y - paoPoints[nPointCount-2].y);
return dfSum < 0;
}
/************************************************************************/
/* reverseWindingOrder() */
/************************************************************************/
void OGRLinearRing::reverseWindingOrder()
{
int pos = 0;
OGRPoint pointA, pointB;
for( int i = 0; i < nPointCount / 2; i++ )
{
getPoint( i, &pointA );
pos = nPointCount - i - 1;
getPoint( pos, &pointB );
setPoint( i, &pointB );
setPoint( pos, &pointA );
}
}
/************************************************************************/
/* closeRing() */
/************************************************************************/
void OGRLinearRing::closeRings()
{
if( nPointCount < 2 )
return;
if( getX(0) != getX(nPointCount-1)
|| getY(0) != getY(nPointCount-1)
|| getZ(0) != getZ(nPointCount-1) )
{
OGRPoint oFirstPoint;
getPoint( 0, &oFirstPoint );
addPoint( &oFirstPoint );
}
}
/************************************************************************/
/* 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;
double prev_diff_x = getX(0) - dfTestX;
double prev_diff_y = getY(0) - dfTestY;
for ( int iPoint = 1; iPoint < iNumPoints; iPoint++ )
{
const double x1 = getX(iPoint) - dfTestX;
const double y1 = getY(iPoint) - dfTestY;
const double x2 = prev_diff_x;
const double y2 = prev_diff_y;
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++;
}
}
prev_diff_x = x1;
prev_diff_y = y1;
}
// 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
if( bTestEnvelope )
{
OGREnvelope extent;
getEnvelope(&extent);
if ( !( dfTestX >= extent.MinX && dfTestX <= extent.MaxX
&& dfTestY >= extent.MinY && dfTestY <= extent.MaxY ) )
{
return 0;
}
}
double prev_diff_x = getX(0) - dfTestX;
double prev_diff_y = getY(0) - dfTestY;
for ( int iPoint = 1; iPoint < iNumPoints; iPoint++ )
{
const double x1 = getX(iPoint) - dfTestX;
const double y1 = getY(iPoint) - dfTestY;
const double x2 = prev_diff_x;
const double y2 = prev_diff_y;
/* 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 )
{
/* If iPoint and iPointPrev are the same, go on */
if( !(x1 == x2 && y1 == y2) )
{
return 1;
}
}
prev_diff_x = x1;
prev_diff_y = y1;
}
return 0;
}
/************************************************************************/
/* CastToLineString() */
/************************************************************************/
/**
* \brief Cast to line string.
*
* The passed in geometry is consumed and a new one returned .
*
* @param poLR the input geometry - ownership is passed to the method.
* @return new geometry.
*/
OGRLineString* OGRLinearRing::CastToLineString(OGRLinearRing* poLR)
{
return TransferMembersAndDestroy(poLR, new OGRLineString());
}
/************************************************************************/
/* GetCasterToLineString() */
/************************************************************************/
OGRCurveCasterToLineString OGRLinearRing::GetCasterToLineString() const {
return (OGRCurveCasterToLineString) OGRLinearRing::CastToLineString;
}
/************************************************************************/
/* GetCasterToLinearRing() */
/************************************************************************/
OGRCurveCasterToLinearRing OGRLinearRing::GetCasterToLinearRing() const {
return (OGRCurveCasterToLinearRing) OGRGeometry::CastToIdentity;
}