Commit fcb6b5a5c55ee35d232f35bcfa9c35aefc00f89e
2020-11-25T22:16:15
Vulkan: Fix precision transformation for geometry shaders When a varying precision mismatch is present between two stages, the SPIR-V transformer transforms the following: in precision1 type1 inVar; out precision2 type2 outVar; void main() { f(inVar); outVar = g(); } to: in precision3 type1 inVarModified; out precision4 type2 outVarModified; precision1 type1 inVarTurnedPrivate; precision2 type2 outVarTurnedPrivate; void main() { // Input preamble inVarTurnedPrivate = inVarModified; f(inVarTurnedPrivate); outVarTurnedPrivate = g(); // Output preamble outVarModified = outVarTurnedPrivate; } This doesn't work for geometry shaders as they take the varying outputs on EmitVertex() as opposed to return from main. This change simply places the output preamble before every EmitVertex() instead of at the end of the shader, if it's a geometry shader. Bug: angleproject:5403 Change-Id: Ie395a3270c6903c54b49f64a26bc5297044cbaeb Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2561939 Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>