Dixel scrolling is not a great idea. If you have enough free memory for the unrolled loop implementation, then running a single pixel scroll twice is actually faster than a single dixel scroll without screen memory contention (although dixel scrolling performs better during memory contention while running the raster scan, if my calculations are correct... I don't have an emulator right now to validate it).
In this case, isn't it more efficient to fetch a byte from memory, scroll it, then write it back, rather than do two in-place rotates?
Though it's only quick if you're shifting in A, which means you can't do EX AF,AF'... So maybe not...
For 2px scrolling, try POP: RL: RL: PUSH. I have one such routine that scrolls some 30x192 area, the resulting speed is about 31T/byte (uncontended), which is close to RL (HL) x2 with nothing in between.
Nienn Heskil wrote: ↑Tue Oct 06, 2020 4:53 pm
For 2px scrolling, try POP: RL: RL: PUSH. I have one such routine that scrolls some 30x192 area, the resulting speed is about 31T/byte (uncontended), which is close to RL (HL) x2 with nothing in between.
I don't see how this could work. Could you share your code ?
Nienn Heskil wrote: ↑Tue Oct 06, 2020 4:53 pm
For 2px scrolling, try POP: RL: RL: PUSH. I have one such routine that scrolls some 30x192 area, the resulting speed is about 31T/byte (uncontended), which is close to RL (HL) x2 with nothing in between.
I don't see how this could work. Could you share your code ?
Einar Saukas wrote: ↑Tue Oct 06, 2020 3:51 pm
if my calculations are correct... I don't have an emulator right now to validate it).
Einar I'm concerned. This is the second post I've seen from you with the above words. Are you okay? Are you being held against your will, somewhere? This is your secret code for "Help. Rescue me!", right?
Please post again with the words "emulation is for n00bs" to confirm. We will immediately create a ticket for this rescue task. You can track the progress being made towards your rescue in the ticket. Please take the time to rate this support on a scale of 1 to 10. Thank you!
