[Mesa-dev] [PATCH 04/15] i965/blorp: Use MSDISPMODE_PERSAMPLE rendering when necessary

[Olivier Galibert]

On Mon, May 21, 2012 at 07:16:35PM -0700, Paul Berry wrote:
> - Add the front-end API to allow the client to request per-sample shading
> (I assume it's glEnable(GL_HAM_SANDWICH) or something like that, in which
> case it should be easy)

There is a "MIN_SAMPLE_SHADING" value in the [0,1] interval which is
set by glMinSampleShading(clampf value).  It tells the minimum ratio
of samples that must be individually shaded.  For instance, if you're
doing 4xMSAA and mss=0.75, then you must shade at least 3 samples.

Always shading all of them as soon as mss is non-zero is compliant to
the spec.  Always shading all of them all the time is actually
compliant to the spec, as far as I can say, but would be a bad idea.

  OG.