tepples wrote:
Would it help to use a pixel shader for palette lookup so that you don't have to store eight copies of the pattern table in memory at once?
I actually do use a fragment shader to interpret the textures I'm generating, which does perform a palette lookup on a texture that is 32 pixels wide by 1 pixel tall. I actually encode the pixel value, attribute, and bg or spr in the rgb values of the actual textures. Without the shader turned on, everything looks sickly greenish/red/blue hues, haha.
I've been trying to think of a way to delegate all of the ppu decoding to the shader since that is performed in parallel on the gpu for each pixel (afaik), however the bandwidth needed for uploading 8k to the gpu every frame, though small, might be prohibitive? I'm not sure. #longtermgoals. It'd be neat if I could get that to work though, because then suddenly live CHR-RAM updates would be possible. Right now, I can only support it during transitions.