kc3-lang/angle

2016-07-24T17:58:50

D3D11: Allow gl_PointCoord when not rendering points. ANGLE D3D11 uses a geometry shader to expand points into quads. This led to an edge case with gl_PointCoord. When the user references gl_PointCoord in the fragment shader but renders with GL_TRIANGLES or other non-point primitives, gl_PointCoord is undefined, but ANGLE would produce a link error. This would break some very odd edge-case shaders (e.g. a shader that is used with both points and triangles). We can fix this by simply adding a dummy PointCoord value to our vertex shader is all cases. If the user renders points, we ignore the PointCoord value passed to the geometry shader. If they render tris or lines and use PointCoord, the shader signatures will match, and PointCoord will even have a sane value of (0.5, 0.5). BUG=angleproject:1380 Change-Id: I322155cd3801d0241cabc9bb639a5aaa502831b3 Reviewed-on: https://chromium-review.googlesource.com/362779 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Zhenyao Mo <zmo@chromium.org> Commit-Queue: Zhenyao Mo <zmo@chromium.org>