interpolate

gistfile1.diff

commit cd56dd7408797189cb5c909618ad4e0d22610f35
Author: Nathan Woodrow <[email protected]>
Date:   Sun Jul 29 22:32:17 2012 +1000

    Add interoplate to QgsGeometry

diff --git a/python/core/qgsgeometry.sip b/python/core/qgsgeometry.sip
index ae805d8..cbd08c2 100644
--- a/python/core/qgsgeometry.sip
+++ b/python/core/qgsgeometry.sip
@@ -297,6 +297,8 @@ not disjoint with existing polygons of the feature*/
 
     /** Returns the smallest convex polygon that contains all the points in the geometry. */
     QgsGeometry* convexHull() /Factory/;
+
+    QgsGeometry* interpolate( double distance );
     
     /** Returns a geometry representing the points shared by this geometry and other. */
     QgsGeometry* intersection(QgsGeometry* geometry) /Factory/;
diff --git a/src/core/qgsgeometry.cpp b/src/core/qgsgeometry.cpp
index ad1b041..2437c48 100644
--- a/src/core/qgsgeometry.cpp
+++ b/src/core/qgsgeometry.cpp
@@ -6409,6 +6409,24 @@ QgsGeometry* QgsGeometry::convexHull()
   CATCH_GEOS( 0 )
 }
 
+QgsGeometry* QgsGeometry::interpolate( double distance )
+{
+    if ( !mGeos )
+    {
+      exportWkbToGeos();
+    }
+    if ( !mGeos )
+    {
+      return 0;
+    }
+
+    try
+    {
+       return fromGeosGeom( GEOSInterpolate( mGeos, distance ) );
+    }
+    CATCH_GEOS( 0 )
+}
+
 QgsGeometry* QgsGeometry::intersection( QgsGeometry* geometry )
 {
   if ( !geometry )
diff --git a/src/core/qgsgeometry.h b/src/core/qgsgeometry.h
index 78ac89a..acdf66a 100644
--- a/src/core/qgsgeometry.h
+++ b/src/core/qgsgeometry.h
@@ -343,6 +343,8 @@ class CORE_EXPORT QgsGeometry
     /** Returns the smallest convex polygon that contains all the points in the geometry. */
     QgsGeometry* convexHull();
 
+    QgsGeometry* interpolate( double distance );
+
     /** Returns a geometry representing the points shared by this geometry and other. */
     QgsGeometry* intersection( QgsGeometry* geometry );