I'm trying to experiment with a simple split screen effect with horizontal scrolling.
From what I've learned so far, this should be a very simple technique which could be summarized in pseudo code as follows:
loop:
;wait for 1 to 0 transition (scanline 0)
;wait for 0 to 1 transition (sprite 0 hit)
;change PPU registers here (one write to $2005 for instance)
jmp loop
vblank:
;update graphics and scroll as desired
rti
Is there anything significant that is missing? I have been able to get a simple experiment working in JNES, but it doesn't seem to work in any other more accurate emulators. I'll keep plugging away at it but any advice would be greatly appreciated.
From what I've learned so far, this should be a very simple technique which could be summarized in pseudo code as follows:
loop:
;wait for 1 to 0 transition (scanline 0)
;wait for 0 to 1 transition (sprite 0 hit)
;change PPU registers here (one write to $2005 for instance)
jmp loop
vblank:
;update graphics and scroll as desired
rti
Is there anything significant that is missing? I have been able to get a simple experiment working in JNES, but it doesn't seem to work in any other more accurate emulators. I'll keep plugging away at it but any advice would be greatly appreciated.