[jsd1982]

It should be possible to have the PPU emulation capture all of the final register state per pixel (or scanline if accuracy isn't paramount) and have the GPU render each pixel using only that state, doing the layer blending, color math, and mode 7 calculations as necessary. Based on MVG's video breaking down the draw commands performed it doesn't look like that's how Super ZSNES have implemented their PPU - it seems to render tile by tile for BGs (and OBJ?) and line by line for mode 7. That'll be a bit inaccurate but it's likely necessary to implement some of their visual enhancement tricks.

[BearOso]

I came up with something similar to your idea, a GPU compute PPU for future Snes9x. What they're doing is using legacy fixed-function API to draw quads, then blend a bump map on with the final image. It's weird. We have the tools to do some really cool things with GPUs, but they chose this. I'm more impressed by all the post-processing shaders people have come up with for all the other emulators.