Making the stream buffer resident increases GPU usage significantly on
some games. This seems to be addressed invalidating the stream buffer
with InvalidateBufferData instead of using a Unmap + Map (with
invalidation flags).
Make stream buffer and cached buffers as resident and query their
address. This allows us to use GPU addresses for several proprietary
Nvidia extensions.
Instead of using as template argument a shared pointer, use the
underlying type and manage shared pointers explicitly. This can make
removing shared pointers from the cache more easy.
While we are at it, make some misc style changes and general
improvements (like insert_or_assign instead of operator[] + operator=).
Namespaces all OpenGL code under the OpenGL namespace.
Prevents polluting the global namespace and allows clear distinction
between other renderers' code in the future.
