Namespaces all OpenGL code under the OpenGL namespace.
Prevents polluting the global namespace and allows clear distinction
between other renderers' code in the future.
We keep track of the current instance and update an uniform in the shaders to let them know which instance they are.
Instanced vertex arrays are not yet implemented.
Ensures both operands have the same sign in the comparison.
While we're at it, we can get rid of the redundant casting of ub_size to
an int. This type will always be trivial and alias a built-in type (not
doing so would break backwards compatibility at a standard level).
This would result in a lot of allocations and related object
construction, just to toss it all away immediately after the call.
These are definitely not intentional, and it was intended that all of
these should have been accessing the static function GetInstance()
through the name itself, not constructed instances.
All tested games that use a single texture show no regression.
Only Texture2D textures are supported right now, each shader gets its own "tex_fs/vs/gs" sampler array to maintain independent textures between shader stages, the textures themselves are reused if possible.
