XBRZ OpenGL ES Optimizations

[kinglir]

Hi All,

First let me say that PPSSPP is awesome and all developers involved should be really proud.

I looked at XBRZ code briefly and would like to ask about color format-related performance (mobile devices).

1. It uses RGBA 32 bit. OpenGL ES textures cannot use 32 bit, so it means you perform 2 conversions per frame - to the scaler and back from the scaler ?

2. What about games that don't need RGBA and RGB (no Alpha) is good enough ? Doesn't it perform more work than needed ?

Thanks again

[Henrik]

OpenGL ES textures can actually use 32-bit just fine so that's not an issue (although it does require a lot of memory bandwidth which may not be ideal for mobile devices).

Probably a little bit more work but hardly worth fixing. Ideally we should reimplement XBRZ to run on the GPU instead, that would be a much bigger performance improvement, probably.