[Mesa-dev] [PATCH] i915: fallback to swrast when gl_PointSize met

[Yuanhan Liu]

On Wed, Feb 22, 2012 at 12:24:11PM -0800, Eric Anholt wrote:
> On Tue, 21 Feb 2012 23:21:07 +0800, Liu Aleaxander <aleaxander at gmail.com> wrote:
> > This patch(the way to fix this issue) is a little weird, as we already
> > fallbacked to swrast when handling gl_PointSize(in vertex shader).
> > Sounds that we didn't fallback enough;) This patch servers as fixing the
> > gl_PointSize issue on Pineview platform.
> > 
> > Since the patch is a little weird, I thought a while for another fix:
> > get the point size at intelRenderStart() (or somewhere else before
> > vtbl.emit_state()) by reading the vertex program output. This is so
> > tricky that I droped this fix.
> > 
> > Any better thoughts(or even fixes) are welcome and appreciate.
> > 
> > This patch would fix piglit glsl-vs-point-size on Pineview(when the GL
> > version 2.0 requirement is removed).
> 
> It looks like to do this right in hardware, you just need to emit
> _TNL_ATTRIB_PSZ with S4_VFMT_POINT_WIDTH in i915ValidateFragmentProgram
> just before COLOR0.

I tried it and it worked. This is so *cool*!

Thanks for the nice tip. Will make a patch for that.

Thanks,
Yuanhan Liu