Reland "Add workaround for unused std140 and shared uniform blocks on MacOS"
On some Mac drivers with shader version 4.1, they will
treat unused std140 and shared uniform blocks' members as inactive. However,
WebGL2.0 based on OpenGL ES3.0.4 requires all members of a named uniform block
declared with a shared or std140 layout qualifier to be considered active.
The uniform block itself is also considered active.
This workaround is to reference all members of unused std140 and shared uniform blocks
at the beginning of the vertex/fragment shader's main().
BUG=chromium:618464
TEST=UniformBufferTest.ActiveUniformBlockNumber
Change-Id: I18da4e2b61b0170068bf5ea38ce54667b0737780
Reviewed-on: https://chromium-review.googlesource.com/395648
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
diff --git a/src/compiler/translator/Compiler.h b/src/compiler/translator/Compiler.h
index be314ac..823832b 100644
--- a/src/compiler/translator/Compiler.h
+++ b/src/compiler/translator/Compiler.h
@@ -132,6 +132,10 @@
// Returns true if, after applying the packing rules in the GLSL 1.017 spec
// Appendix A, section 7, the shader does not use too many uniforms.
bool enforcePackingRestrictions();
+ // Insert statements to reference all members in unused uniform blocks with standard and shared
+ // layout. This is to work around a Mac driver that treats unused standard/shared
+ // uniform blocks as inactive.
+ void useAllMembersInUnusedStandardAndSharedBlocks(TIntermNode *root);
// Insert statements to initialize output variables in the beginning of main().
// This is to avoid undefined behaviors.
void initializeOutputVariables(TIntermNode *root);