FBFetch refactor + arm support

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"
 #include "GrGLContext.h"
@@ skipping 216 matching lines @@
         fVertexArrayObjectSupport = version >= GR_GL_VER(3, 0) ||
                                     ctxInfo.hasExtension("GL_ARB_vertex_array_object");
     } else {
         fVertexArrayObjectSupport = version >= GR_GL_VER(3, 0) ||
                                     ctxInfo.hasExtension("GL_OES_vertex_array_object");
     }
 
     if (kGLES_GrGLStandard == standard) {
         if (ctxInfo.hasExtension("GL_EXT_shader_framebuffer_fetch")) {
             fFBFetchType = kEXT_FBFetchType;
+            fFBFetchColorName = "gl_LastFragData[0]";
+            fFBFetchExtensionString = "GL_EXT_shader_framebuffer_fetch";
         } else if (ctxInfo.hasExtension("GL_NV_shader_framebuffer_fetch")) {
             fFBFetchType = kNV_FBFetchType;
+            fFBFetchColorName = "gl_LastFragData[0]";
+            fFBFetchExtensionString = "GL_NV_shader_framebuffer_fetch";
+        } else if (ctxInfo.hasExtension("GL_ARM_shader_framebuffer_fetch")) {
+            // The arm extension requires specifically enabling MSAA fetching per sample.
+            // On some devices this may have a perf hit.  Also multiple render targets are disabled
+            GR_GL_CALL(gli, Enable(GR_GL_FETCH_PER_SAMPLE_ARM));
+            fFBFetchType = kARM_FBFetchType;
+            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);
     this->initStencilFormats(ctxInfo);
 
     /**************************************************************************
@@ skipping 523 matching lines @@
     GR_STATIC_ASSERT(3 == kES_3_0_MSFBOType);
     GR_STATIC_ASSERT(4 == kES_Apple_MSFBOType);
     GR_STATIC_ASSERT(5 == kES_IMG_MsToTexture_MSFBOType);
     GR_STATIC_ASSERT(6 == kES_EXT_MsToTexture_MSFBOType);
     GR_STATIC_ASSERT(SK_ARRAY_COUNT(kMSFBOExtStr) == kLast_MSFBOType + 1);
 
     static const char* kFBFetchTypeStr[] = {
         "None",
         "EXT",
         "NV",
+        "ARM",
     };
     GR_STATIC_ASSERT(0 == kNone_FBFetchType);
     GR_STATIC_ASSERT(1 == kEXT_FBFetchType);
     GR_STATIC_ASSERT(2 == kNV_FBFetchType);
+    GR_STATIC_ASSERT(3 == kARM_FBFetchType);
     GR_STATIC_ASSERT(SK_ARRAY_COUNT(kFBFetchTypeStr) == kLast_FBFetchType + 1);
 
     static const char* kInvalidateFBTypeStr[] = {
         "None",
         "Discard",
         "Invalidate",
     };
     GR_STATIC_ASSERT(0 == kNone_InvalidateFBType);
     GR_STATIC_ASSERT(1 == kDiscard_InvalidateFBType);
     GR_STATIC_ASSERT(2 == kInvalidate_InvalidateFBType);
@@ skipping 37 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;
 }