> But the OpenGL spec says that the fog color is calculated on a _pixel_ > basis and not on a _vertex_ basis. Indeed the result is different, > especially in long polygons that span from the front way to the back. Does 4 do pixel-based fog?
> Mach64 is able to do the fog properly, i.e., on a pixel basis, but _not_ Why? I know - it's only ATI who can answer this question...:) > when alpha blending since it uses the path on chip. So the problem is only > what to do when both fog and alpha blending are enabled. Are there many apps using this effects together? > The solution of using these depending of the contents of a env var is a > compromise so that gamers achieve a better gameplay sacrifying a little > the visual quality and the OpenGL conformance. Actually, end users in 80% (or 99%?) do not specially care about conformance. The visual quality really matters. > There are other situations as this one. Leif checked on Unreal and there > is one (also when alpha blending) that happens and according with his > experiments reverting to software leads to a severe performance hit. It was predictable, wasn't it? And any predictions about _visual_ difference between these two methods? Will users see the difference easily? Say, if you get 10* speedup with 5% worse quality (I do not really know how to measure it though:) - almost nobody will really use SW mode. > > Cool! And the default version will be HW-based non-conformant, won't it? > This is very subjective, but if we assume that DRI aims to be OpenGL > conformant, I vote for sw-based conformant... :)) I see your point. Again "real life vs standards":). It's time for new poll on dri.sourceforge.net:) > > BTW, I can seriously recommend 3ddesktop as a test tool. It supports > > several effects (blending, textures, etc. with on/off switching) so its > > behavior could give a lot of hints to the developers. > I'll check it. Thanks a lot. I'm not lobbying it. I just like it - and would like it to work properly on Mach64 - today I have a lot of problems with it - which I don't have in pure SW mode. Cheers, Sergey _______________________________________________ Dri-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/dri-devel
