The point of this change is to allow greater flexibility and reduce
confusion.
When instanced meshes are implemented, MeshTools::interleave() can be
used for creating interleaved buffers with per-instance data and then
the call to Mesh::setCount() will be harmful and/or confusing, becuase
the user would in fact want to call Mesh::setInstanceCount() instead.
Similarly, MeshTools::compressIndices() can be used to create index
buffer for more than one mesh.
GL 4.4 has ARB_buffer_storage, which (in relatively distant future) will
mean that the current way of Buffer::setData() will be deprecated in
favor of Buffer::setStorage(), similarly as Texture::setStorage()
replaced Texture::setImage(). Thus any function which calls
Buffer::setData() internally is not future-proof.
The old MeshTools::compressIndices() and MeshTools::interleave()
overloads are marked as deprecated and will be removed in future
release.
Only one value from these two was used in the end, wasting precious
bytes. Also these two values were used to differentiate between indexed
and non-indexed mesh (instead of relying on actual index buffer being
bound), which was very confusing. This approach looks more clean. The
MeshView class is not yet updated, as the change would expose some
features that aren't possible in current implementation (base vertex
specification).
Merged Mesh::setVertexCount() and Mesh::setIndexCount() into one
Mesh::setCount(), the two original functions are now guarded aliases to
the new one, are marked as deprecated and will be removed in future
release, similarly for the getters.
In particular, if the mesh is indexed, setVertexCount() does nothing and
vertexCount() returns 0. The setIndexCount() and indexCount() do and
return the same regardless of whether the mesh is indexed or not.
Vladimír Vondruš