[Feature][OGR] Support Triangle, TIN and PolyhedralSurface geometry types by mapping them to Triangle and MultiPolygon respectively

Author: manisandro

src/core/qgsogrutils.cpp

@@ -221,6 +221,64 @@ QgsGeometry QgsOgrUtils::ogrGeometryToQgsGeometry( OGRGeometryH geom )
   unsigned char *wkb = new unsigned char[memorySize];
   OGR_G_ExportToWkb( geom, ( OGRwkbByteOrder ) QgsApplication::endian(), wkb );
 
+  // Read original geometry type
+  uint32_t origGeomType;
+  memcpy( &origGeomType, wkb + 1, sizeof( uint32_t ) );
+  bool hasZ = ( origGeomType >= 1000 && origGeomType < 2000 ) || ( origGeomType >= 3000 && origGeomType < 4000 );
+  bool hasM = ( origGeomType >= 2000 && origGeomType < 3000 ) || ( origGeomType >= 3000 && origGeomType < 4000 );
+
+  // PolyhedralSurface and TINs are not supported, map them to multipolygons...
+  if ( origGeomType % 1000 == 16 ) // is TIN, TINZ, TINM or TINZM
+  {
+    // TIN has the same wkb layout as a multipolygon, just need to overwrite the geom types...
+    int nDims = 2 + hasZ + hasM;
+    uint32_t newMultiType = static_cast<uint32_t>( QgsWkbTypes::zmType( QgsWkbTypes::MultiPolygon, hasZ, hasM ) );
+    uint32_t newSingleType = static_cast<uint32_t>( QgsWkbTypes::zmType( QgsWkbTypes::Polygon, hasZ, hasM ) );
+    unsigned char *wkbptr = wkb;
+
+    // Endianness
+    wkbptr += 1;
+
+    // Overwrite geom type
+    memcpy( wkbptr, &newMultiType, sizeof( uint32_t ) );
+    wkbptr += 4;
+
+    // Geom count
+    uint32_t numGeoms;
+    memcpy( &numGeoms, wkb + 5, sizeof( uint32_t ) );
+    wkbptr += 4;
+
+    // For each part, overwrite the geometry type to polygon (Z|M)
+    for ( uint32_t i = 0; i < numGeoms; ++i )
+    {
+      // Endianness
+      wkbptr += 1;
+
+      // Overwrite geom type
+      memcpy( wkbptr, &newSingleType, sizeof( uint32_t ) );
+      wkbptr += sizeof( uint32_t );
+
+      // skip coordinates
+      uint32_t nRings;
+      memcpy( &nRings, wkbptr, sizeof( uint32_t ) );
+      wkbptr += sizeof( uint32_t );
+
+      for ( uint32_t j = 0; j < nRings; ++j )
+      {
+        uint32_t nPoints;
+        memcpy( &nPoints, wkbptr, sizeof( uint32_t ) );
+        wkbptr += sizeof( uint32_t ) + sizeof( double ) * nDims * nPoints;
+      }
+    }
+  }
+  else if ( origGeomType % 1000 == 15 ) // PolyhedralSurface, PolyhedralSurfaceZ, PolyhedralSurfaceM or PolyhedralSurfaceZM
+  {
+    // PolyhedralSurface has the same wkb layout as a MultiPolygon, just need to overwrite the geom type...
+    uint32_t newType = static_cast<uint32_t>( QgsWkbTypes::zmType( QgsWkbTypes::MultiPolygon, hasZ, hasM ) );
+    // Overwrite geom type
+    memcpy( wkb + 1, &newType, sizeof( uint32_t ) );
+  }
+
   QgsGeometry g;
   g.fromWkb( wkb, memorySize );
   return g;

src/providers/ogr/qgsogrprovider.cpp

@@ -765,6 +765,17 @@ QStringList QgsOgrProvider::subLayers() const
         fCount[wkbUnknown] = 0;
       }
 
+      // List TIN and PolyhedralSurface as MultiPolygon
+      if ( fCount.contains( wkbTIN ) )
+      {
+        fCount[wkbMultiPolygon] = fCount.value( wkbMultiPolygon ) + fCount[wkbTIN];
+        fCount.remove( wkbTIN );
+      }
+      if ( fCount.contains( wkbPolyhedralSurface ) )
+      {
+        fCount[wkbMultiPolygon] = fCount.value( wkbMultiPolygon ) + fCount[wkbPolyhedralSurface];
+        fCount.remove( wkbPolyhedralSurface );
+      }
       // When there are CurvePolygons, promote Polygons
       if ( fCount.contains( wkbPolygon ) && fCount.contains( wkbCurvePolygon ) )
       {
@@ -1164,6 +1175,14 @@ QgsWkbTypes::Type QgsOgrProvider::wkbType() const
   {
     wkb = QgsWkbTypes::multiType( wkb );
   }
+  if ( wkb % 1000 == 15 ) // is PolyhedralSurface, PolyhedralSurfaceZ, PolyhedralSurfaceM or PolyhedralSurfaceZM => map to MultiPolygon
+  {
+    wkb = static_cast<QgsWkbTypes::Type>( wkb - 9 );
+  }
+  else if ( wkb % 1000 == 16 ) // is TIN, TINZ, TINM or TINZM => map to MultiPolygon
+  {
+    wkb = static_cast<QgsWkbTypes::Type>( wkb - 10 );
+  }
   return wkb;
 }
 

tests/src/python/test_provider_ogr.py

@@ -17,7 +17,7 @@
 import sys
 import tempfile
 
-from qgis.core import QgsVectorLayer, QgsVectorDataProvider, QgsWkbTypes, QgsFeature
+from qgis.core import QgsVectorLayer, QgsVectorDataProvider, QgsWkbTypes, QgsFeature, QgsFeatureRequest
 from qgis.testing import (
     start_app,
     unittest
@@ -255,6 +255,43 @@ def testGdbFilter(self):
         while it.nextFeature(f):
             self.assertTrue(f.attribute("text") == "shape 2")
 
+    def testTriangleTINPolyhedralSurface(self):
+        """ Test support for Triangles (mapped to Polygons) """
+        testsets = (
+            ("Triangle((0 0, 0 1, 1 1, 0 0))", QgsWkbTypes.Triangle, "Triangle ((0 0, 0 1, 1 1, 0 0))"),
+            ("Triangle Z((0 0 1, 0 1 2, 1 1 3, 0 0 1))", QgsWkbTypes.TriangleZ, "TriangleZ ((0 0 1, 0 1 2, 1 1 3, 0 0 1))"),
+            ("Triangle M((0 0 4, 0 1 5, 1 1 6, 0 0 4))", QgsWkbTypes.TriangleM, "TriangleM ((0 0 4, 0 1 5, 1 1 6, 0 0 4))"),
+            ("Triangle ZM((0 0 0 1, 0 1 2 3, 1 1 4 5, 0 0 0 1))", QgsWkbTypes.TriangleZM, "TriangleZM ((0 0 0 1, 0 1 2 3, 1 1 4 5, 0 0 0 1))"),
+
+            ("TIN (((0 0, 0 1, 1 1, 0 0)),((0 0, 1 0, 1 1, 0 0)))", QgsWkbTypes.MultiPolygon, "MultiPolygon (((0 0, 0 1, 1 1, 0 0)),((0 0, 1 0, 1 1, 0 0)))"),
+            ("TIN Z(((0 0 0, 0 1 1, 1 1 1, 0 0 0)),((0 0 0, 1 0 0, 1 1 1, 0 0 0)))", QgsWkbTypes.MultiPolygonZ, "MultiPolygonZ (((0 0 0, 0 1 1, 1 1 1, 0 0 0)),((0 0 0, 1 0 0, 1 1 1, 0 0 0)))"),
+            ("TIN M(((0 0 0, 0 1 2, 1 1 3, 0 0 0)),((0 0 0, 1 0 4, 1 1 3, 0 0 0)))", QgsWkbTypes.MultiPolygonM, "MultiPolygonM (((0 0 0, 0 1 2, 1 1 3, 0 0 0)),((0 0 0, 1 0 4, 1 1 3, 0 0 0)))"),
+            ("TIN ZM(((0 0 0 0, 0 1 1 2, 1 1 1 3, 0 0 0 0)),((0 0 0 0, 1 0 0 4, 1 1 1 3, 0 0 0 0)))", QgsWkbTypes.MultiPolygonZM, "MultiPolygonZM (((0 0 0 0, 0 1 1 2, 1 1 1 3, 0 0 0 0)),((0 0 0 0, 1 0 0 4, 1 1 1 3, 0 0 0 0)))"),
+
+            ("PolyhedralSurface (((0 0, 0 1, 1 1, 0 0)),((0 0, 1 0, 1 1, 0 0)))", QgsWkbTypes.MultiPolygon, "MultiPolygon (((0 0, 0 1, 1 1, 0 0)),((0 0, 1 0, 1 1, 0 0)))"),
+            ("PolyhedralSurface Z(((0 0 0, 0 1 1, 1 1 1, 0 0 0)),((0 0 0, 1 0 0, 1 1 1, 0 0 0)))", QgsWkbTypes.MultiPolygonZ, "MultiPolygonZ (((0 0 0, 0 1 1, 1 1 1, 0 0 0)),((0 0 0, 1 0 0, 1 1 1, 0 0 0)))"),
+            ("PolyhedralSurface M(((0 0 0, 0 1 2, 1 1 3, 0 0 0)),((0 0 0, 1 0 4, 1 1 3, 0 0 0)))", QgsWkbTypes.MultiPolygonM, "MultiPolygonM (((0 0 0, 0 1 2, 1 1 3, 0 0 0)),((0 0 0, 1 0 4, 1 1 3, 0 0 0)))"),
+            ("PolyhedralSurface ZM(((0 0 0 0, 0 1 1 2, 1 1 1 3, 0 0 0 0)),((0 0 0 0, 1 0 0 4, 1 1 1 3, 0 0 0 0)))", QgsWkbTypes.MultiPolygonZM, "MultiPolygonZM (((0 0 0 0, 0 1 1 2, 1 1 1 3, 0 0 0 0)),((0 0 0 0, 1 0 0 4, 1 1 1 3, 0 0 0 0)))")
+        )
+        for row in testsets:
+            datasource = os.path.join(self.basetestpath, 'test.csv')
+            with open(datasource, 'wt') as f:
+                f.write('id,WKT\n')
+                f.write('1,"%s"' % row[0])
+
+            vl = QgsVectorLayer(datasource, 'test', 'ogr')
+            self.assertTrue(vl.isValid())
+            self.assertEqual(vl.wkbType(), row[1])
+
+            f = QgsFeature()
+            self.assertTrue(vl.getFeatures(QgsFeatureRequest(1)).nextFeature(f))
+            self.assertTrue(f.geometry())
+            self.assertEqual(f.geometry().geometry().asWkt(), row[2])
+
+    """PolyhedralSurface, Tin => mapped to MultiPolygon
+          Triangle => mapped to Polygon
+      """
+
 
 if __name__ == '__main__':
     unittest.main()