Blender Git Loki

Fix for [#23375] "texture2D in custom 2D filters can get texture outside of game, resulting in ugliness" reported by Jacob F.

The 2D Filter system now only copies the game viewport instead of the whole window. This prevents 2D Filters from grabbing data outside of the game viewport. The textures for 2D filters are now also not forced to be powers of two (if NPOT textures are supported), which can save a little bit of VRAM.