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Yuanhan Liu authored
This patch add the support of gl_PointCoord gl builtin variable for platform gen4 and gen5(ILK). Unlike gen6+, we don't have a hardware support of gl_PointCoord, means hardware will not calculate the interpolation coefficient for you. Instead, you should handle it yourself in sf shader stage. But badly, gl_PointCoord is a FS instead of VS builtin variable, thus it's not included in c.vue_map generated in VS stage. Thus the current code doesn't aware of this attribute. And to handle it correctly, we need add it to c.vue_map manually to let SF shader generate the needed interpolation coefficient for FS shader. SF stage has it's own copy of vue_map, thus I think it's safe to do it manually. Since handling gl_PointCoord for gen4 and gen5 platforms is somehow a little special, I added a lot of comments and hope I didn't overdo it ;) v2: add a /* _NEW_BUFFERS */ comment to note the state flag dependency and also add the _NEW_BUFFERS dirty mask (Eric). Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=45975 Piglit: glsl-fs-pointcoord and fbo-gl_pointcoord NOTE: This is a candidate for stable release branches. Signed-off-by: Yuanhan Liu <yuanhan.liu@linux.intel.com> Reviewed-by: Eric Anholt <eric@anholt.net>
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