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Better approach to split lines. Fixes bug #4618

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This commit is contained in:
Marco Hugentobler 2013-02-08 16:56:50 +01:00
parent e635f04bcc
commit c90870d095
1 changed files with 23 additions and 23 deletions
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46
src/core/qgsgeometry.cpp
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@ -6225,45 +6225,45 @@ int QgsGeometry::splitLinearGeometry( GEOSGeometry *splitLine, QList<QgsGeometry
return 1;
}
//first union all the polygon rings together (to get them noded, see JTS developer guide)
GEOSGeometry* nodedGeometry = nodeGeometries( splitLine, mGeos );
if ( !nodedGeometry )
//check that split line has no linear intersection
int linearIntersect = GEOSRelatePattern( mGeos, splitLine, "1********" );
if ( linearIntersect > 0 )
{
return 3; //an error occured during noding
return 3;
}
GEOSGeometry *mergedLines = GEOSLineMerge( nodedGeometry );
if ( !mergedLines )
{
GEOSGeom_destroy( nodedGeometry );
return 4;
}
GEOSGeometry* splitGeom = GEOSDifference( mGeos, splitLine );
QVector<GEOSGeometry*> lineGeoms;
QVector<GEOSGeometry*> testedGeometries;
for ( int i = 0; i < GEOSGetNumGeometries( mergedLines ); i++ )
int splitType = GEOSGeomTypeId( splitGeom );
if ( splitType == GEOS_MULTILINESTRING )
{
const GEOSGeometry *testing = GEOSGetGeometryN( mergedLines, i );
if ( lineContainedInLine( testing, mGeos ) == 1 )
int nGeoms = GEOSGetNumGeometries( splitGeom );
for ( int i = 0; i < nGeoms; ++i )
{
testedGeometries << GEOSGeom_clone( testing );
lineGeoms << GEOSGeom_clone( GEOSGetGeometryN( splitGeom, i ) );
}
}
else
{
lineGeoms << GEOSGeom_clone( splitGeom );
}
mergeGeometriesMultiTypeSplit( testedGeometries );
mergeGeometriesMultiTypeSplit( lineGeoms );
if ( testedGeometries.size() > 0 )
if ( lineGeoms.size() > 0 )
{
GEOSGeom_destroy( mGeos );
mGeos = testedGeometries[0];
mGeos = lineGeoms[0];
mDirtyWkb = true;
}
for ( int i = 1; i < testedGeometries.size(); ++i )
newGeometries << fromGeosGeom( testedGeometries[i] );
for ( int i = 1; i < lineGeoms.size(); ++i )
{
newGeometries << fromGeosGeom( lineGeoms[i] );
}
GEOSGeom_destroy( nodedGeometry );
GEOSGeom_destroy( mergedLines );
GEOSGeom_destroy( splitGeom );
return 0;
}