Disable single channel renderability for ANGLE ES2

Bug: 720325

Change-Id: Ib55c7a0c59a23b8dc012e04b626010de7da2921b
Reviewed-on: https://skia-review.googlesource.com/18485
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>

3 files changed, 10 insertions, 2 deletions

diff --git a/src/gpu/gl/GrGLCaps.cpp b/src/gpu/gl/GrGLCaps.cpp
index ba5ad6e31e..5aca304194 100644
--- a/src/gpu/gl/GrGLCaps.cpp
+++ b/src/gpu/gl/GrGLCaps.cpp
@@ -1800,10 +1800,13 @@ void GrGLCaps::initConfigTable(const GrContextOptions& contextOptions,
             GR_GL_ALPHA;
         fConfigTable[kAlpha_8_GrPixelConfig].fSwizzle = GrSwizzle::AAAA();
     }
-    if (this->textureRedSupport() ||
+    if ((this->textureRedSupport() &&
+                (ctxInfo.renderer() != kANGLE_GrGLRenderer || kGLES_GrGLStandard != standard)) ||
         (kStandard_MSFBOType == this->msFBOType() && ctxInfo.renderer() != kOSMesa_GrGLRenderer)) {
+        // ES2 ANGLE seems to disallow single channel renderability (despite advertising the
+        // "GL_EXT_texture_rg" extension.
         // OpenGL 3.0+ (and GL_ARB_framebuffer_object) supports ALPHA8 as renderable.
-        // However, osmesa fails if it used even when GL_ARB_framebuffer_object is present.
+        // However, osmesa fails if it is used even when GL_ARB_framebuffer_object is present.
         // Core profile removes ALPHA8 support, but we should have chosen R8 in that case.
         fConfigTable[kAlpha_8_GrPixelConfig].fFlags |= allRenderFlags;
     }
diff --git a/src/gpu/gl/GrGLUtil.cpp b/src/gpu/gl/GrGLUtil.cpp
index 41c57eb1e1..cf4615ad86 100644
--- a/src/gpu/gl/GrGLUtil.cpp
+++ b/src/gpu/gl/GrGLUtil.cpp
@@ -330,6 +330,10 @@ GrGLRenderer GrGLGetRendererFromString(const char* rendererString) {
         if (0 == strncmp(rendererString, kMaliTStr, SK_ARRAY_COUNT(kMaliTStr) - 1)) {
             return kMaliT_GrGLRenderer;
         }
+        static const char kANGLEStr[] = "ANGLE";
+        if (0 == strncmp(rendererString, kANGLEStr, SK_ARRAY_COUNT(kANGLEStr) - 1)) {
+            return kANGLE_GrGLRenderer;
+        }
     }
     return kOther_GrGLRenderer;
 }
diff --git a/src/gpu/gl/GrGLUtil.h b/src/gpu/gl/GrGLUtil.h
index 261a4cd22d..fc2594a3a0 100644
--- a/src/gpu/gl/GrGLUtil.h
+++ b/src/gpu/gl/GrGLUtil.h
@@ -58,6 +58,7 @@ enum GrGLRenderer {
     kIntel6xxx_GrGLRenderer,
     /** T-6xx, T-7xx, or T-8xx */
     kMaliT_GrGLRenderer,
+    kANGLE_GrGLRenderer,
     kOther_GrGLRenderer
 };