commit 924b7de2c7c039cc5f01eda2a41363f1b803c840
author Ian Ewell <ewell@google.com> Thu Jan 21 13:54:28 2016 -0500
committer Ian Ewell <ewell@google.com> Thu Jan 21 22:41:02 2016 +0000
tree b5006590310d7a20e741e2d52e264e8db45ed4fa
parent d544cc9ff4a48adb2b0013e8abc9b9dd51bc8d18

Always write to gl_Position when compiling shaders with
SH_GLSL_COMPATIBILITY_OUTPUT.

BUG=angleproject:1277

Change-Id: Ib820a46151637e8c61e94b966b970de46ccca6b9
Reviewed-on: https://chromium-review.googlesource.com/323160
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tryjob-Request: Jamie Madill <jmadill@chromium.org>
Tested-by: Ian Ewell <ewell@google.com>

src/compiler/translator/Compiler.cpp

diff --git a/src/compiler/translator/Compiler.cpp b/src/compiler/translator/Compiler.cpp
index 18c977f..18524ce 100644
--- a/src/compiler/translator/Compiler.cpp
+++ b/src/compiler/translator/Compiler.cpp
@@ -322,7 +322,10 @@
         if (success && (compileOptions & SH_CLAMP_INDIRECT_ARRAY_BOUNDS))
             arrayBoundsClamper.MarkIndirectArrayBoundsForClamping(root);
 
-        if (success && shaderType == GL_VERTEX_SHADER && (compileOptions & SH_INIT_GL_POSITION))
+        // gl_Position is always written in compatibility output mode
+        if (success && shaderType == GL_VERTEX_SHADER &&
+            ((compileOptions & SH_INIT_GL_POSITION) ||
+             (outputType == SH_GLSL_COMPATIBILITY_OUTPUT)))
             initializeGLPosition(root);
 
         // This pass might emit short circuits so keep it before the short circuit unfolding