English Amiga Board - View Single Post - Coder shows possible way in which some elements of Street Fighter 2 might be possible

mcgeezer · 30 January 2021, 20:56

On the subject of the tech in the video, I would probably do it like this.

Dual Playfield mode with fetch mode x1 and 64 wide sprites.

Back playfield used for background image, Front playfield used for foreground animations. For animations I would probably just cut out the animated sections where needed and change the bitplane pointers per animation. Each scene would need some sort of driver to determine what animations need to be done and any copper effects (easy to do).

Dedicate all blitter and cpu time to reconstructing the player sprites from 16x16 tiles, 4 even sprites for the 1st player, 4 odd sprites for the 2nd player, this then allows for 16 colours dedicated per player (64 colours in total without copper effects), each player then has maxium 128x224 size.

No shifting is required because blits are placed in the hardware sprites and only copy mode is required, this negates the need to hold sprite masks and saves CPU/BLIT time massively. With hardware sprites you negate the need for double buffering - again, massive memory saver.

I'm not a fan of the genre or Street Fighter so some assumptions that I make are likely wrong. Firing objects across the playfield may be tricky, haven't thought that much ahead.

But keep in mind.... everything HAS to work in 2mb of CHIP ram otherwise - NOBODY WOULD HAVE PURCHASED THE GAME!!!!

30 January 2021, 20:56	#58
mcgeezer Registered User Join Date: Oct 2017 Location: Sunderland, England Posts: 2,702	On the subject of the tech in the video, I would probably do it like this. Dual Playfield mode with fetch mode x1 and 64 wide sprites. Back playfield used for background image, Front playfield used for foreground animations. For animations I would probably just cut out the animated sections where needed and change the bitplane pointers per animation. Each scene would need some sort of driver to determine what animations need to be done and any copper effects (easy to do). Dedicate all blitter and cpu time to reconstructing the player sprites from 16x16 tiles, 4 even sprites for the 1st player, 4 odd sprites for the 2nd player, this then allows for 16 colours dedicated per player (64 colours in total without copper effects), each player then has maxium 128x224 size. No shifting is required because blits are placed in the hardware sprites and only copy mode is required, this negates the need to hold sprite masks and saves CPU/BLIT time massively. With hardware sprites you negate the need for double buffering - again, massive memory saver. I'm not a fan of the genre or Street Fighter so some assumptions that I make are likely wrong. Firing objects across the playfield may be tricky, haven't thought that much ahead. But keep in mind.... everything HAS to work in 2mb of CHIP ram otherwise - NOBODY WOULD HAVE PURCHASED THE GAME!!!! Last edited by mcgeezer; 30 January 2021 at 21:15.