On Tue, Jun 12, 2012 at 01:50:08PM +0200, Christoph Bumiller wrote: > > First question: how many depths should be computed, and for which > > coordinates? Which of these values is associated with which sample? > > One for each sample point. The depth buffer will be multisampled as well. > Coverage sampling (CSAA) where you have extra coverage samples that do > NOT (necessarily) correspond to color sample locations are not covered > by the GL spec, it's vendor-specific.
Ok. So that means that if the shader writes z, you have to do full supersampling then. > > Second question: how many samples should be shaded, and for which > > coordinates? What is the impact of depth testing failure? > > As many as the user requested via glMinSampleShading, and the sample > locations to choose seem to be up to the implementation. Do you know what's usually expected? Center of collapsed samples, one of the samples, center of the pixel? > > Third question: what happens when a variable has a "sample" qualifier > > in the fragment shader? Or "centroid"? > > "When interpolating variables declared using sample in when MULTISAMPLE > is enabled, the fragment shader will be invoked separately for each (!) > covered sample and the variable will be sampled at the corresponding > sample point." So a "sample" anywhere means full supersampling, ok. Thanks, OG. _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
