fixed an issue where the texture was not rebuild correctly for rendering

if both REBUILD_GEOMETRY and REBUILD_TEXTURE were set in the rebuild_ flag 
and the number of faces and vertices in the mesh have not changed

closes #1670

git-svn-id: http://www.openflipper.org/svnrepo/OpenFlipper/branches/Free@16965 383ad7c9-94d9-4d36-a494-682f7c89f535

ACG/GL/DrawMesh.cc

@@ -241,8 +241,8 @@ DrawMeshT<Mesh>::rebuild()
     prevNumVerts_ = mesh_.n_vertices();
   }
 
-  // support faster update by only updating vertices
-  if (!bTriangleRebuild && !bVertexRebuild && (rebuild_ & REBUILD_GEOMETRY))
+  // support faster update by only updating vertices (do a complete update if the textures have to be rebuild)
+  if (!bTriangleRebuild && !bVertexRebuild && (rebuild_ & REBUILD_GEOMETRY) && !(rebuild_ & REBUILD_TEXTURES))
   {
     // only update vertices, i.e. update values of vertices