QgsGeometry QgsGeometryAnalyzer::locateBetweenMeasures( double fromMeasure, double toMeasure, const QgsGeometry& lineGeom )
{
if ( lineGeom.isEmpty() )
{
return QgsGeometry();
}
QgsMultiPolyline resultGeom;
//need to go with WKB and z coordinate until QgsGeometry supports M values
QByteArray wkb( lineGeom.exportToWkb() );
QgsConstWkbPtr wkbPtr( wkb );
wkbPtr.readHeader();
QgsWkbTypes::Type wkbType = lineGeom.wkbType();
if ( wkbType != QgsWkbTypes::LineString25D && wkbType != QgsWkbTypes::MultiLineString25D )
{
return QgsGeometry();
}
if ( wkbType == QgsWkbTypes::LineString25D )
{
locateBetweenWkbString( wkbPtr, resultGeom, fromMeasure, toMeasure );
}
else if ( wkbType == QgsWkbTypes::MultiLineString25D )
{
int nLines;
wkbPtr >> nLines;
for ( int i = 0; i < nLines; ++i )
{
wkbPtr.readHeader();
wkbPtr = locateBetweenWkbString( wkbPtr, resultGeom, fromMeasure, toMeasure );
}
}
QgsGeometry* QgsGeometryAnalyzer::locateBetweenMeasures( double fromMeasure, double toMeasure, const QgsGeometry* lineGeom )
{
if ( !lineGeom )
{
return nullptr;
}
QgsMultiPolyline resultGeom;
//need to go with WKB and z coordinate until QgsGeometry supports M values
QgsConstWkbPtr wkbPtr( lineGeom->asWkb(), lineGeom->wkbSize() );
wkbPtr.readHeader();
QGis::WkbType wkbType = lineGeom->wkbType();
if ( wkbType != QGis::WKBLineString25D && wkbType != QGis::WKBMultiLineString25D )
{
return nullptr;
}
if ( wkbType == QGis::WKBLineString25D )
{
locateBetweenWkbString( wkbPtr, resultGeom, fromMeasure, toMeasure );
}
else if ( wkbType == QGis::WKBMultiLineString25D )
{
int nLines;
wkbPtr >> nLines;
for ( int i = 0; i < nLines; ++i )
{
wkbPtr.readHeader();
wkbPtr = locateBetweenWkbString( wkbPtr, resultGeom, fromMeasure, toMeasure );
}
}
QgsGeometry* QgsGeometryAnalyzer::locateBetweenMeasures( double fromMeasure, double toMeasure, QgsGeometry* lineGeom )
{
if ( !lineGeom )
{
return 0;
}
QgsMultiPolyline resultGeom;
//need to go with WKB and z coordinate until QgsGeometry supports M values
unsigned char* lineWkb = lineGeom->asWkb();
unsigned char* ptr = lineWkb + 1;
QGis::WkbType wkbType;
memcpy( &wkbType, ptr, sizeof( wkbType ) );
ptr += sizeof( wkbType );
if ( wkbType != QGis::WKBLineString25D && wkbType != QGis::WKBMultiLineString25D )
{
return 0;
}
if ( wkbType == QGis::WKBLineString25D )
{
locateBetweenWkbString( ptr, resultGeom, fromMeasure, toMeasure );
}
else if ( wkbType == QGis::WKBMultiLineString25D )
{
int* nLines = ( int* )ptr;
ptr += sizeof( int );
for ( int i = 0; i < *nLines; ++i )
{
ptr += ( 1 + sizeof( wkbType ) );
ptr = locateBetweenWkbString( ptr, resultGeom, fromMeasure, toMeasure );
}
}
if ( resultGeom.size() < 1 )
{
return 0;
}
return QgsGeometry::fromMultiPolyline( resultGeom );
}
