?? ogrmultipolygon.cpp
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/******************************************************************************
* $Id: ogrmultipolygon.cpp 10646 2007-01-18 02:38:10Z warmerdam $
*
* Project: OpenGIS Simple Features Reference Implementation
* Purpose: The OGRMultiPolygon 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: ogrmultipolygon.cpp 10646 2007-01-18 02:38:10Z warmerdam $");
/************************************************************************/
/* OGRMultiPolygon() */
/************************************************************************/
OGRMultiPolygon::OGRMultiPolygon()
{
}
/************************************************************************/
/* getGeometryType() */
/************************************************************************/
OGRwkbGeometryType OGRMultiPolygon::getGeometryType() const
{
if( getCoordinateDimension() == 3 )
return wkbMultiPolygon25D;
else
return wkbMultiPolygon;
}
/************************************************************************/
/* getGeometryName() */
/************************************************************************/
const char * OGRMultiPolygon::getGeometryName() const
{
return "MULTIPOLYGON";
}
/************************************************************************/
/* addGeometryDirectly() */
/************************************************************************/
OGRErr OGRMultiPolygon::addGeometryDirectly( OGRGeometry * poNewGeom )
{
if( poNewGeom->getGeometryType() != wkbPolygon
&& poNewGeom->getGeometryType() != wkbPolygon25D )
return OGRERR_UNSUPPORTED_GEOMETRY_TYPE;
return OGRGeometryCollection::addGeometryDirectly( poNewGeom );
}
/************************************************************************/
/* clone() */
/************************************************************************/
OGRGeometry *OGRMultiPolygon::clone() const
{
OGRMultiPolygon *poNewGC;
poNewGC = new OGRMultiPolygon;
poNewGC->assignSpatialReference( getSpatialReference() );
for( int i = 0; i < getNumGeometries(); i++ )
{
poNewGC->addGeometry( getGeometryRef(i) );
}
return poNewGC;
}
/************************************************************************/
/* importFromWkt() */
/* */
/* Instantiate from well known text format. Currently this is */
/* `MULTIPOLYGON ((x y, x y, ...),(x y, ...),...)'. */
/************************************************************************/
OGRErr OGRMultiPolygon::importFromWkt( char ** ppszInput )
{
char szToken[OGR_WKT_TOKEN_MAX];
const char *pszInput = *ppszInput;
OGRErr eErr = OGRERR_NONE;
/* -------------------------------------------------------------------- */
/* Clear existing rings. */
/* -------------------------------------------------------------------- */
empty();
/* -------------------------------------------------------------------- */
/* Read and verify the MULTIPOLYGON keyword token. */
/* -------------------------------------------------------------------- */
pszInput = OGRWktReadToken( pszInput, szToken );
if( !EQUAL(szToken,getGeometryName()) )
return OGRERR_CORRUPT_DATA;
/* -------------------------------------------------------------------- */
/* The next character should be a ( indicating the start of the */
/* list of polygons. */
/* -------------------------------------------------------------------- */
pszInput = OGRWktReadToken( pszInput, szToken );
if( EQUAL(szToken,"EMPTY") )
{
*ppszInput = (char *) pszInput;
return OGRERR_NONE;
}
if( szToken[0] != '(' )
return OGRERR_CORRUPT_DATA;
/* -------------------------------------------------------------------- */
/* If the next token is EMPTY, then verify that we have proper */
/* EMPTY format will a trailing closing bracket. */
/* -------------------------------------------------------------------- */
OGRWktReadToken( pszInput, szToken );
if( EQUAL(szToken,"EMPTY") )
{
pszInput = OGRWktReadToken( pszInput, szToken );
pszInput = OGRWktReadToken( pszInput, szToken );
*ppszInput = (char *) pszInput;
if( !EQUAL(szToken,")") )
return OGRERR_CORRUPT_DATA;
else
return OGRERR_NONE;
}
/* ==================================================================== */
/* Read each polygon in turn. Note that we try to reuse the same */
/* point list buffer from ring to ring to cut down on */
/* allocate/deallocate overhead. */
/* ==================================================================== */
OGRRawPoint *paoPoints = NULL;
int nMaxPoints = 0;
double *padfZ = NULL;
do
{
OGRPolygon *poPolygon = new OGRPolygon();
/* -------------------------------------------------------------------- */
/* The next character should be a ( indicating the start of the */
/* list of polygons. */
/* -------------------------------------------------------------------- */
pszInput = OGRWktReadToken( pszInput, szToken );
if( szToken[0] != '(' )
{
eErr = OGRERR_CORRUPT_DATA;
break;
}
/* -------------------------------------------------------------------- */
/* Loop over each ring in this polygon. */
/* -------------------------------------------------------------------- */
do
{
int nPoints = 0;
/* -------------------------------------------------------------------- */
/* Read points for one line from input. */
/* -------------------------------------------------------------------- */
pszInput = OGRWktReadPoints( pszInput, &paoPoints, &padfZ, &nMaxPoints,
&nPoints );
if( pszInput == NULL )
{
eErr = OGRERR_CORRUPT_DATA;
break;
}
/* -------------------------------------------------------------------- */
/* Create the new line, and add to collection. */
/* -------------------------------------------------------------------- */
OGRLinearRing *poLine;
poLine = new OGRLinearRing();
poLine->setPoints( nPoints, paoPoints, padfZ );
poPolygon->addRingDirectly( poLine );
/* -------------------------------------------------------------------- */
/* Read the delimeter following the ring. */
/* -------------------------------------------------------------------- */
pszInput = OGRWktReadToken( pszInput, szToken );
} while( szToken[0] == ',' && eErr == OGRERR_NONE );
/* -------------------------------------------------------------------- */
/* Verify that we have a closing bracket. */
/* -------------------------------------------------------------------- */
if( eErr == OGRERR_NONE )
{
if( szToken[0] != ')' )
eErr = OGRERR_CORRUPT_DATA;
else
pszInput = OGRWktReadToken( pszInput, szToken );
}
/* -------------------------------------------------------------------- */
/* Add the polygon to the MULTIPOLYGON. */
/* -------------------------------------------------------------------- */
if( eErr == OGRERR_NONE )
eErr = addGeometryDirectly( poPolygon );
} while( szToken[0] == ',' && eErr == OGRERR_NONE );
/* -------------------------------------------------------------------- */
/* freak if we don't get a closing bracket. */
/* -------------------------------------------------------------------- */
CPLFree( paoPoints );
CPLFree( padfZ );
if( eErr != OGRERR_NONE )
return eErr;
if( szToken[0] != ')' )
return OGRERR_CORRUPT_DATA;
*ppszInput = (char *) pszInput;
return OGRERR_NONE;
}
/************************************************************************/
/* exportToWkt() */
/* */
/* Translate this structure into it's well known text format */
/* equivelent. This could be made alot more CPU efficient! */
/************************************************************************/
OGRErr OGRMultiPolygon::exportToWkt( char ** ppszDstText ) const
{
char **papszLines;
int iLine, nCumulativeLength = 0, nValidPolys=0;
OGRErr eErr;
/* -------------------------------------------------------------------- */
/* Build a list of strings containing the stuff for each ring. */
/* -------------------------------------------------------------------- */
papszLines = (char **) CPLCalloc(sizeof(char *),getNumGeometries());
for( iLine = 0; iLine < getNumGeometries(); iLine++ )
{
eErr = getGeometryRef(iLine)->exportToWkt( &(papszLines[iLine]) );
if( eErr != OGRERR_NONE )
return eErr;
if( !EQUALN(papszLines[iLine],"POLYGON (", 9) )
{
CPLDebug( "OGR", "OGRMultiPolygon::exportToWkt() - skipping %s.",
papszLines[iLine] );
CPLFree( papszLines[iLine] );
papszLines[iLine] = NULL;
continue;
}
nCumulativeLength += strlen(papszLines[iLine] + 8);
nValidPolys++;
}
/* -------------------------------------------------------------------- */
/* Return MULTIPOLYGON EMPTY if we get no valid polygons. */
/* -------------------------------------------------------------------- */
if( nValidPolys == 0 )
{
*ppszDstText = CPLStrdup("MULTIPOLYGON EMPTY");
return OGRERR_NONE;
}
/* -------------------------------------------------------------------- */
/* Allocate exactly the right amount of space for the */
/* aggregated string. */
/* -------------------------------------------------------------------- */
*ppszDstText = (char *) VSIMalloc(nCumulativeLength+getNumGeometries()+20);
if( *ppszDstText == NULL )
return OGRERR_NOT_ENOUGH_MEMORY;
/* -------------------------------------------------------------------- */
/* Build up the string, freeing temporary strings as we go. */
/* -------------------------------------------------------------------- */
strcpy( *ppszDstText, "MULTIPOLYGON (" );
for( iLine = 0; iLine < getNumGeometries(); iLine++ )
{
if( papszLines[iLine] == NULL )
continue;
if( iLine > 0 )
strcat( *ppszDstText, "," );
strcat( *ppszDstText, papszLines[iLine] + 8 );
VSIFree( papszLines[iLine] );
}
strcat( *ppszDstText, ")" );
CPLFree( papszLines );
return OGRERR_NONE;
}
/************************************************************************/
/* get_Area() */
/************************************************************************/
/**
* Compute area of multipolygon.
*
* The area is computed as the sum of the areas of all polygon members
* in this collection.
*
* @return computed area.
*/
double OGRMultiPolygon::get_Area() const
{
double dfArea = 0.0;
int iPoly;
for( iPoly = 0; iPoly < getNumGeometries(); iPoly++ )
{
OGRPolygon *poPoly = (OGRPolygon *) getGeometryRef( iPoly );
dfArea += poPoly->get_Area();
}
return dfArea;
}
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