commit 89dd8f37017f55dca821a8b9cf33f4fb09532d70
author Qiankun Miao <qiankun.miao@intel.com> Wed Nov 09 12:59:30 2016 +0000
committer Commit Bot <commit-bot@chromium.org> Thu Nov 10 16:41:25 2016 +0000
tree 214cce542269fb9031d966e94f1d5e1f8f42db7b
parent d9c6f50118a0647451ba40c0743c82712d96cd45

Remove invariant declaration in vertex shader for translation from ESSL 3.00 to GLSL <= 4.1

This is a follow-up patch of
https://chromium-review.googlesource.com/408569. This CL removes
invariant declaration in ESSL 3.00 vertex shader, such like:
"
out vec4 foo;
invariant foo;
"

This CL also adds the workarounds in libANGLE.

BUG=chromium:639760
TEST=webgl2_conformance

Change-Id: I568ab51a9a2f5da10d1aff0b63aae8805097e081
Reviewed-on: https://chromium-review.googlesource.com/409157
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>

src/compiler/translator/Compiler.cpp

diff --git a/src/compiler/translator/Compiler.cpp b/src/compiler/translator/Compiler.cpp
index 08806bc..53b021a 100644
--- a/src/compiler/translator/Compiler.cpp
+++ b/src/compiler/translator/Compiler.cpp
@@ -103,6 +103,22 @@
             output == SH_GLSL_400_CORE_OUTPUT || output == SH_GLSL_410_CORE_OUTPUT);
 }
 
+bool RemoveInvariant(sh::GLenum shaderType,
+                     int shaderVersion,
+                     ShShaderOutput outputType,
+                     ShCompileOptions compileOptions)
+{
+    if ((compileOptions & SH_DONT_REMOVE_INVARIANT_FOR_FRAGMENT_INPUT) == 0 &&
+        shaderType == GL_FRAGMENT_SHADER && IsGLSL420OrNewer(outputType))
+        return true;
+
+    if ((compileOptions & SH_REMOVE_INVARIANT_AND_CENTROID_FOR_ESSL3) != 0 &&
+        shaderVersion >= 300 && shaderType == GL_VERTEX_SHADER && IsGLSL410OrOlder(outputType))
+        return true;
+
+    return false;
+}
+
 size_t GetGlobalMaxTokenSize(ShShaderSpec spec)
 {
     // WebGL defines a max token legnth of 256, while ES2 leaves max token
@@ -394,8 +410,7 @@
              (outputType == SH_GLSL_COMPATIBILITY_OUTPUT)))
             initializeGLPosition(root);
 
-        if (success && !(compileOptions & SH_DONT_REMOVE_INVARIANT_FOR_FRAGMENT_INPUT) &&
-            shaderType == GL_FRAGMENT_SHADER && IsGLSL420OrNewer(outputType))
+        if (success && RemoveInvariant(shaderType, shaderVersion, outputType, compileOptions))
             sh::RemoveInvariantDeclaration(root);
 
         // This pass might emit short circuits so keep it before the short circuit unfolding