Talk:Petit Computer 3/@comment-15296152-20140916233546/@comment-15296152-20140917052331

Well, my original idea was based on possible shader use for an SNES homebrew emulator someone is making. The SNES only had space for storing one set of scanline information for backgrounds, so SNES programs had to update within the H-Blank for each scanline to pull off the effect. With PTC3 though, this is not a problem. They can have an entire section for holding each scanline's BG information all at once, so they could still do one single polygon quad, and reference this section to render the backgrounds (one polygon quad per layer). The vertical coordinate of the screen space would decide what scanline information they'd use (gl_FragCoord.y in GLSL).