Cleanup texture code.
Implement additional functions.
Cleanup
Outline GL sampler caches.
Add sampler object extension usage for GL3
Cleanup
Fix segfault, need a separate method that waits till GL is initialized.
Cleanup
Cleanup
Cleanup, isfont is no longer a solution.
Cleanup
Cleanup
Add some Direct3D texture code.
Implement screen_set_viewport for Direct3D11
Add some DX11 surface code.
Cleanup
Cleans up parameter string implementations putting them where they belong.
Cleanup
Add missing include.
Remove platform dependent include.