BradLarson/GPUImage — pull request #1595 by jackwu95 (2014-05-28 16:47:15+00:00)
Title: Add category on GPUImage to allow replacing a sub texture of GPUPicture

This allows better memory management in terms of textures and easier re-using of GPUImagePicture's

Also has performance benefits when using a smaller sub-rect.
When you use subtexture replace, targets and options are kept for the GPUImagePicture which is also convenient.