fix for FB fetch on nexus 10 ES3.0

src/gpu/gl/GrGLCaps.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGLCaps.h"
 
@@ skipping 32 matching lines @@
     fImagingSupport = false;
     fTwoFormatLimit = false;
     fFragCoordsConventionSupport = false;
     fVertexArrayObjectSupport = false;
     fES2CompatibilitySupport = false;
     fUseNonVBOVertexAndIndexDynamicData = false;
     fIsCoreProfile = false;
     fFullClearIsFree = false;
     fDropsTileOnZeroDivide = false;
     fFBFetchSupport = false;
+    fFBFetchNeedsCustomOutput = false;
     fFBFetchColorName = NULL;
     fFBFetchExtensionString = NULL;
 
     fReadPixelsSupportedCache.reset();
 }
 
 GrGLCaps::GrGLCaps(const GrGLCaps& caps) : GrDrawTargetCaps() {
     *this = caps;
 }
 
@@ skipping 23 matching lines @@
     fImagingSupport = caps.fImagingSupport;
     fTwoFormatLimit = caps.fTwoFormatLimit;
     fFragCoordsConventionSupport = caps.fFragCoordsConventionSupport;
     fVertexArrayObjectSupport = caps.fVertexArrayObjectSupport;
     fES2CompatibilitySupport = caps.fES2CompatibilitySupport;
     fUseNonVBOVertexAndIndexDynamicData = caps.fUseNonVBOVertexAndIndexDynamicData;
     fIsCoreProfile = caps.fIsCoreProfile;
     fFullClearIsFree = caps.fFullClearIsFree;
     fDropsTileOnZeroDivide = caps.fDropsTileOnZeroDivide;
     fFBFetchSupport = caps.fFBFetchSupport;
+    fFBFetchNeedsCustomOutput = caps.fFBFetchNeedsCustomOutput;
     fFBFetchColorName = caps.fFBFetchColorName;
     fFBFetchExtensionString = caps.fFBFetchExtensionString;
 
     return *this;
 }
 
 bool GrGLCaps::init(const GrGLContextInfo& ctxInfo, const GrGLInterface* gli) {
 
     this->reset();
     if (!ctxInfo.isInitialized()) {
@@ skipping 137 matching lines @@
 
     if (kGL_GrGLStandard == standard) {
         fES2CompatibilitySupport = ctxInfo.hasExtension("GL_ARB_ES2_compatibility");
     }
     else {
         fES2CompatibilitySupport = true;
     }
 
     if (kGLES_GrGLStandard == standard) {
         if (ctxInfo.hasExtension("GL_EXT_shader_framebuffer_fetch")) {
+            fFBFetchNeedsCustomOutput = (version >= GR_GL_VER(3, 0));
             fFBFetchSupport = true;
             fFBFetchColorName = "gl_LastFragData[0]";
             fFBFetchExtensionString = "GL_EXT_shader_framebuffer_fetch";
         } else if (ctxInfo.hasExtension("GL_NV_shader_framebuffer_fetch")) {
+            // Actually, we haven't seen an ES3.0 device with this extension yet, so we don't know
+            fFBFetchNeedsCustomOutput = false;
             fFBFetchSupport = true;
             fFBFetchColorName = "gl_LastFragData[0]";
             fFBFetchExtensionString = "GL_NV_shader_framebuffer_fetch";
         } else if (ctxInfo.hasExtension("GL_ARM_shader_framebuffer_fetch")) {
             // The arm extension also requires an additional flag which we will set onResetContext
-            // This is all temporary.
+            fFBFetchNeedsCustomOutput = false;
             fFBFetchSupport = true;
             fFBFetchColorName = "gl_LastFragColorARM";
             fFBFetchExtensionString = "GL_ARM_shader_framebuffer_fetch";
         }
     }
 
     // Adreno GPUs have a tendency to drop tiles when there is a divide-by-zero in a shader
     fDropsTileOnZeroDivide = kQualcomm_GrGLVendor == ctxInfo.vendor();
 
     this->initFSAASupport(ctxInfo, gli);
@@ skipping 754 matching lines @@
     r.appendf("Two Format Limit: %s\n", (fTwoFormatLimit ? "YES": "NO"));
     r.appendf("Fragment coord conventions support: %s\n",
              (fFragCoordsConventionSupport ? "YES": "NO"));
     r.appendf("Vertex array object support: %s\n", (fVertexArrayObjectSupport ? "YES": "NO"));
     r.appendf("Use non-VBO for dynamic data: %s\n",
              (fUseNonVBOVertexAndIndexDynamicData ? "YES" : "NO"));
     r.appendf("Full screen clear is free: %s\n", (fFullClearIsFree ? "YES" : "NO"));
     r.appendf("Drops tile on zero divide: %s\n", (fDropsTileOnZeroDivide ? "YES" : "NO"));
     return r;
 }