To encapsulate endcap functions from public API, add methods to
tell the number of patch points needed (GetNumLocalPoints()) and
to compute those patch points as a result of change of basis from
the refined vertices (ComputeLocalPointValues()).
ComputeLocalPointValues takes contiguous source data of all levels
including level0 control vertices.
All examples, regression tests and tutorials directly looked into
opensubdiv source directory to grab the header files. This is somewhat
convenient during development but they can mistakenly access private
header files.
With this change, when OPENSUBDIV_INCLUDE_DIR is given to cmake,
it will be used as an include search path to build examples etc.
Otherwise it follows the same behavior as before.
Also replaces include references to the files in regression dir
to be relative, and cleanups some copy-paste patterns.
As a preparation for retiring DrawContext, move SupportsAdaptiveTessellation
method to examples/common/glUtils, which is renamed and namespaced
from gl_common.{cpp,h} to be consistent to other files.
Same renamings applied to other example files.
This examples is rewritten as a more comprehensive example
of Far and Osd APIs to generate batched index buffer and
vertex buffer, as well as sharing same topology and stencil
table among multiple objects.
Also this change includes an experimental code path of using
glMultiDrawElementsIndirect. It's currently incomplete due to
the missing interface of osd tessellation shader.
