Revisit singular vertex fix for FarSubdivisionTables

The previous fix pointed far indexing tables to the origin vertex
of duped singular verts.

This fix goes one step further and actually shifts all vertex indexing
to start at the end of the coarse mesh vertices, using the space for
data that was previously occupied by duplicated singular verts.

The consequence is that client code no longer needs to duplicate vertex
data in vertex buffers (huzzah !).

- fix FarSubdivisionTablesFactory to shift factory vertex table offsets using Hbr's
  singular verts map
- fix schema table factories (Catmark, Loop...) to correctly use these offsets
- remove vertex data duplication code from osdPolySmooth example
- remove some (unrelated) cruft from glViewer example
- shape_utils unfortunately still needs to dubplicate the singular verts to
  allow the coarse edge drawing in our example viewers to work correctly
  (although it could be fixed to avoid data duplication too...)

fixes #241

examples/glViewer/viewer.cpp

@@ -215,8 +215,7 @@ Stopwatch g_fpsTimer;
 
 // geometry
 std::vector<float> g_orgPositions,
-                   g_positions,
-                   g_normals;
+                   g_positions;
 
 Scheme             g_scheme;
 
@@ -620,9 +619,7 @@ createOsdMesh( const std::string &shape, int level, int kernel, Scheme scheme=kC
     OsdHbrMesh * hmesh = simpleHbr<OpenSubdiv::OsdVertex>(shape.c_str(), scheme, g_orgPositions,
                                                           g_displayStyle == kFaceVaryingColor);
 
-    g_normals.resize(g_orgPositions.size(),0.0f);
     g_positions.resize(g_orgPositions.size(),0.0f);
-    calcNormals( hmesh, g_orgPositions, g_normals );
 
     // save coarse topology (used for coarse mesh drawing)
     g_coarseEdges.clear();

examples/osdPolySmooth/osdPolySmooth.cpp

@@ -813,13 +813,6 @@ MStatus OsdPolySmooth::compute( const MPlug& plug, MDataBlock& data ) {
                 float const * vertex3fArray = inMeshFn.getRawPoints(&returnStatus);
                 vertexBuffer->UpdateData(vertex3fArray, 0, numVertices );
 
-                // Hbr dupes singular vertices during Mesh::Finish() - we need
-                // to duplicate their positions in the vertex buffer.
-                std::vector<std::pair<int, int> > const splits = hbrMesh->GetSplitVertices();
-                for (int i=0; i<(int)splits.size(); ++i) {
-                    vertexBuffer->UpdateData(&vertex3fArray[0]+splits[i].second*numVertexElements, splits[i].first, 1);
-                }
-
                 // == Delete HBR
                 // Can now delete the hbrMesh as we will only be referencing the farMesh from this point on
                 delete hbrMesh;

opensubdiv/far/bilinearSubdivisionTablesFactory.h

@@ -101,8 +101,7 @@ FarBilinearSubdivisionTablesFactory<T,U>::Create( FarMeshFactory<T,U> * meshFact
     for (int level=1; level<=maxlevel; ++level) {
 
         // pointer to the first vertex corresponding to this level
-        vertexOffset = tablesFactory._vertVertIdx[level-1] +
-            (int)tablesFactory._vertVertsList[level-1].size();
+        vertexOffset = tablesFactory._faceVertIdx[level];
         result->_vertsOffsets[level] = vertexOffset;
 
         // Face vertices

opensubdiv/far/catmarkSubdivisionTablesFactory.h

@@ -110,8 +110,7 @@ FarCatmarkSubdivisionTablesFactory<T,U>::Create( FarMeshFactory<T,U> * meshFacto
     for (int level=1; level<=maxlevel; ++level) {
 
         // pointer to the first vertex corresponding to this level
-        vertexOffset = tablesFactory._vertVertIdx[level-1] +
-            (int)tablesFactory._vertVertsList[level-1].size();
+        vertexOffset = tablesFactory._faceVertIdx[level];
         result->_vertsOffsets[level] = vertexOffset;
 
         // Face vertices

opensubdiv/far/loopSubdivisionTablesFactory.h

@@ -103,8 +103,7 @@ FarLoopSubdivisionTablesFactory<T,U>::Create( FarMeshFactory<T,U> * meshFactory,
     for (int level=1; level<=maxlevel; ++level) {
 
         // pointer to the first vertex corresponding to this level
-        vertexOffset = tablesFactory._vertVertIdx[level-1] +
-            (int)tablesFactory._vertVertsList[level-1].size();
+        vertexOffset = tablesFactory._edgeVertIdx[level];
         result->_vertsOffsets[level] = vertexOffset;
 
         // Edge vertices

opensubdiv/far/subdivisionTablesFactory.h

@@ -171,6 +171,9 @@ FarSubdivisionTablesFactory<T,U>::FarSubdivisionTablesFactory( HbrMesh<T> const
         }
     }
 
+    int nsingulars = (int)mesh->GetSplitVertices().size();
+    vertCounts[0] -= nsingulars;
+
     // Per-level offset to the first vertex of each type in the global vertex map
     _vertVertsList[0].reserve( vertCounts[0] );
     for (int l=1; l<(maxlevel+1); ++l) {

regression/common/shape_utils.h

@@ -778,7 +778,8 @@ copyVertexPositions( shape const * sh, OpenSubdiv::HbrMesh<T> * mesh, std::vecto
 
     std::copy(sh->verts.begin(), sh->verts.end(), verts.begin());
 
-    // Sometimes Hbr dupes some vertices during Mesh::Finish()
+    // Sometimes Hbr dupes some vertices during Mesh::Finish() and our example 
+    // code uses those vertices to draw coarse control cages and such
     std::vector<std::pair<int, int> > const splits = mesh->GetSplitVertices();
     for (int i=0; i<(int)splits.size(); ++i) {
         memcpy(&verts[splits[i].first*3], &sh->verts[splits[i].second*3], 3*sizeof(float));