> But why I am getting a proper scaled and filtered image on other cores like Snes9X,
> etc using the same shaders that cause problem on MAME, btw I am testing this on
> RetroArch using the libretro versions...
> I though it would be the same on the other emulators but only MAME experience this
Complain to the RA guys then, they can maybe add some ugly hack to do it since that's what they're all about doing anyway, ugly "user-pleasing" hacks without caring what the damage is.
The MAME RA port is absolutely abysmal anyway, so them breaking it further for the sake of things like this won't make much difference.
Also you should probably have stated that from the beginning anyway, because if you had I wouldn't have bothered to reply at all.
MAME isn't Snes9x or anything else, MAME is MAME, MAME does things the way MAME does them because it has to consider a lot more use cases which would break the kind of cheap hacks you might otherwise get away with. As I said already, the shaders make far too many assumptions to work in all cases with a proper emulation model like MAME. MAME can't assume you're only going to run SNES emulation and therefore that certain things will never happen, the problem is the shaders expect certain assumptions to be made.
No different to why MAME isn't going to do high resolution PSX rendering or widescreen patches, because it's at odds with doing things properly and would require hacks etc. to work. Just because something else does it, doesn't mean it's a good idea or that MAME will do it, or that MAME will be compromised to work with bad assumptions made by other software (in this case the shaders)