Ah, reading my original email again is quite funny. Without thinking it through too well, and without having the time to actually check my code just then.. I ended up writing a CI equivalent :D (luckily I did remember at least that the premultiply command is CI only!)
I wrote a bit about premultiplication some time back here if it helps: http://psonice.untergrund.net/tutorials.html (scroll down a bit for the premultiplication section). Cwright: after all the GMA bashing we've done over the years, do you realise it's the same GPU as the iphone? Not sure which GMA models but at least the newer ones I think have a PowerVR SGX GPU hiding inside. I've not heard much complaint about it on iphone though, maybe it's intel's drivers sucking compared to imaginations? Or maybe it's only the newer GMA chips that have the SGX, they do seem to have improved a bit (and remember, we're talking an "upgrade" to a mobile GPU in a desktop/laptop here!) Chris On 20 Jun 2010, at 15:26, Christopher Wright wrote: >>> [cwood] > >>> vec4 output = color + Color; // urgh at the naming there! ;D >>> output.rgb *= output.a; >>> return output; > >>> [cwright] >>> use a different name, like vec4 comspositeColor. > >>> [gtoledo] >>> Thanks for that suggestion as well... not working for me though. I just >>> keep getting a "void function cannot return value", and I've tried a few >>> variations on this theme. > > > So literal :) > > a fragment shader doesn't _return_ a value (hence the "void main" at the > beginning), it sets gl_FragColor. This was probably a brevity oversight on > cwood's part, but the idea is sound -- you could alternatively do something > like this: > > vec4 compositeColor = color + Color; > compositeColor.rgb *= compositeColor.a; > gl_FragColor = compositeColor; // <--- not return > > (after more testing, it's just this shader that's exploding my machine, not > other glsl shaders in QC... no idea what's going on with that... one would > think that GMAs were the worst GPUs on the planet, with drivers to match or > something ;) > > -- > [ christopher wright ] > cwri...@kineme.net > http://kineme.net/ > > _______________________________________________ > Do not post admin requests to the list. They will be ignored. > Quartzcomposer-dev mailing list (Quartzcomposer-dev@lists.apple.com) > Help/Unsubscribe/Update your Subscription: > http://lists.apple.com/mailman/options/quartzcomposer-dev/psonice%40gmail.com > > This email sent to pson...@gmail.com _______________________________________________ Do not post admin requests to the list. They will be ignored. Quartzcomposer-dev mailing list (Quartzcomposer-dev@lists.apple.com) Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/quartzcomposer-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
