> Most SNES games run on a internal res of 256x224, but because some games run on
> hi-res mode 512x448 I am always stuck on an uneven stretched res of 512x224 which
> make all filters to scale the image very badly, compared to other emulators like
> Snes9X, Bsnes, etc...
> So my question is, how can I force the snes driver to display on a internal and more
> standard res of 256x224, it doesn't matter if a few games get broken in the process,
> or is there another way to have the game properly scaled...
> By the way I tried already GroovyMAME stretch option, clean, unclean, unholy
> options... nothing worked so far...
> As a last attempt I took a look at the snes.c driver on the source and the ppu.c too
> if I can tweak some lines and after compiling it I didn't get any good results
> I appreciate any help, thanks!!!!!1
this is a problem with shaders that assume things about pixels.
in reality a system doesn't have a fixed horizontal resolution, some even mix 'resolutions' between layers because different chips can output at different rates. (typical examples, Galaxian starfield and the PC-FX VDPs)
MAME drivers have to use a resolution that is the lowest multiple of all the possible selections (which is possible as they're all driven by the same clock) in order for things like mid-screen raster effects to work.
if you don't do that then you'd always have a frame delay between a game trying to use a mid-screen effect and MAME changing resolution to that, which wouldn't be correct.
proper shaders, like the CRT ones care less about pixels, much as the TV wouldn't care about pixels.