- fixed missing PatchDescriptor functionality for Loop triangle
- add new PatchDescriptor::Type for Gregory triangle
- extended PatchParam boundary mask from 4 to 5 bits (!)
- added new PatchParam methods for parameterization of triangles
- extended PatchMap to support triangular patches
- added basis evaluation for triangular patch types
These are now redundant since all bspline patches are encoded in
the patch tables consistently using 16 point indices with boundary
and corner edges indicated in the boundary mask of the patch params.
- extend Far::PatchTables data structures & interfaces to store requisite
information for channels of face-varying bi-cubic patches
- implement gather function in Far::PatchTablesFactory to populate face-varying
channels with adaptive patches
- extend accessor interface in Vtr::Level
- propagate code fall-out throughout OpenSubdiv code base, examples & tutorials
- extend vtrViewer code to visualize tessellated bi-cubic face-varying patches
- renamed Sdc::Type to SchemeType and TypeTraits to SchemeTypeTraits
- renamed TYPE_ prefix to SCHEME_
- updated all usage within core library
- updated all usage in examples, tutorials, etc.
- split Far::PatchDescriptor into its own class (mirrors Far::PatchParam)
- hide PatchArray as a private internal structure
- add public accessors patterned after Far::TopologyRefiner (returning Vtr::Arrays)
- propagate new API to all dependent code
note: some direct table accessors have not been removed *yet* - see code for details
