David Haywood’s MAME(tm) WIP

Sean’s Stage in SFIII New Generation uses a different compression scheme to the other games. For some reason, Capcom decided that one stage, in one game would use a different system. The Compression used on this level supports 8bpp tiles instead of 6, thus allowing for more colours, but a less efficient compression scheme. I’ve spent some time looking at this, and mostly figured out how it works. There are still a few problems, but I now have reocgnizable background tiles at least.

I’ve come up with a preliminary implementation of Full-screen zoom, used pretty heavily by JoJo and Warzard.

Right now the code assumes that the view will never be zoomed more than twice the normal visible area away, as it’s a framebuffer zoom I’d expect there to be some sensible limit in hardware such as this, although testing on the real hardware would be good.

Test source code can be found at http://mamedev.emulab.it/haze/misc/cps3_220607_fsz.zip Again I’m not posting binaries.

Note, I haven’t managed to fix the reported crash in SFIII NG, I’m looking into it now.

*edit* latest source is here
http://mamedev.emulab.it/haze/misc/cps3_250607.zip

I think I’ve fixed the palettes. There was a single bit to select which one to use (the one in the main list, or the one in the sublists)

not tested too much so far, but everything I’ve seen looks much better. The only ‘bad’ colours I can see now are where there should be shadow sprites / alpha blending effects.

I posted this on Mameworld yesterday because I couldn’t access my site.

Anyway, I’ve hooked up a preliminary spritezoom in CPS3 (this progress is in Mame0116u2) and passed the information on how it works to ElSemi so that he can implement it in his standalone emulator.

Basically each part of a sprite can specify the height / width of that part in pixels, and the number of tiles that are used to cover that height / width. Previously I was using the upper 4 bits of the height / width as the number of tiles instead. After realising that this was wrong and finding the actual # of tiles bit implementing the zoom was fairly straightforward.

JoJo / JoJo Ba have a test mode where you can test the sprites. This is only available when the game is set to ‘Developer Mode’ ( 0×7x region code in the BIOS ) As the current MAME driver is set to this while I work on it, you can access the hidden mode by holding Player 1 button 1 when entering test mode.

Warzard also uses it for the character profiles in the background on the select screen. Compare this to the shot in the previous news post.

Street Fighter 3 3rd Strike uses i during the intro for some portraits, these looked terrible with the previous preview code.

and it’s also used for the ‘Fight’ graphics at the start of the round on most of the games.

there are many other places where it’s used as Capcom made fairly extensive use of it for special effects etc. So having it implemented improves a large number of little things.

CPS3 also has ‘Line Zoom’ and ‘Frame Zoom’ Frame Zoom seems to be some kind of Framebuffer zoom, allowing the player to see a greater / smaller area of the playfield. Implenenting that *fast* in MAME could be a pain ;-) I remember having to do similar for ‘Rabbit’ and it slowing the whole thing down significantly due to the overhead of having to render and clear an extended display area. Anyway, I’ll look into it at some point, but first I’d like to look into fixing the remaining sprite palette issues both myself and ElSemi are having. He’s using one sprite colour register, I’m using the other, there must be some way to combine them, or select which one to use.

I fixed a few problems (broken fastboot hacks are bad mmmk) and Warzard now has sprites, and the Sprite positions in the other games seem more correct.

The zoom isn’t emulated on the sprites yet, hence the bad looking ones on the first shot in the backgrond.

you may have noticed the site was down for a bit yesterday, basically the bandwidth usage was killing the mameworld.info server, so Twisty disabled it for a while. Go easy on the refresh button guys ;-)