#9480: New 'pointOnSurface' method for QgsGeometry

Author: ahuarte47

python/core/qgsgeometry.sip

@@ -322,6 +322,9 @@ class QgsGeometry
     * and for point based geometries, the point itself is returned */
     QgsGeometry* centroid() /Factory/;
 
+    /** Returns a point within a geometry */
+    QgsGeometry* pointOnSurface();
+
     /** Returns the smallest convex polygon that contains all the points in the geometry. */
     QgsGeometry* convexHull() /Factory/;
 

src/core/qgsgeometry.cpp

@@ -145,6 +145,7 @@ static GEOSInit geosinit;
 #define GEOSArea(g, a) GEOSArea( (GEOSGeometry*) g, a )
 #define GEOSTopologyPreserveSimplify(g, t) GEOSTopologyPreserveSimplify( (GEOSGeometry*) g, t )
 #define GEOSGetCentroid(g) GEOSGetCentroid( (GEOSGeometry*) g )
+#define GEOSPointOnSurface(g) GEOSPointOnSurface( (GEOSGeometry*) g )
 
 #define GEOSCoordSeq_getSize(cs,n) GEOSCoordSeq_getSize( (GEOSCoordSequence *) cs, n )
 #define GEOSCoordSeq_getX(cs,i,x) GEOSCoordSeq_getX( (GEOSCoordSequence *)cs, i, x )
@@ -5623,6 +5624,21 @@ QgsGeometry* QgsGeometry::centroid()
   CATCH_GEOS( 0 )
 }
 
+QgsGeometry* QgsGeometry::pointOnSurface()
+{
+  if ( mDirtyGeos )
+    exportWkbToGeos();
+
+  if ( !mGeos )
+    return 0;
+
+  try
+  {
+    return fromGeosGeom( GEOSPointOnSurface( mGeos ) );
+  }
+  CATCH_GEOS( 0 )
+}
+
 QgsGeometry* QgsGeometry::convexHull()
 {
   if ( mDirtyGeos )

src/core/qgsgeometry.h

@@ -363,6 +363,9 @@ class CORE_EXPORT QgsGeometry
     * and for point based geometries, the point itself is returned */
     QgsGeometry* centroid();
 
+    /** Returns a point within a geometry */
+    QgsGeometry* pointOnSurface();
+
     /** Returns the smallest convex polygon that contains all the points in the geometry. */
     QgsGeometry* convexHull();