Implement difference clip rects with window rectangles

src/gpu/GrCaps.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrCaps.h"
 #include "GrContextOptions.h"
+#include "GrWindowRectangles.h"
 
 GrShaderCaps::GrShaderCaps() {
     fShaderDerivativeSupport = false;
     fGeometryShaderSupport = false;
     fPathRenderingSupport = false;
     fDstReadInShaderSupport = false;
     fDualSourceBlendingSupport = false;
     fIntegerSupport = false;
     fTexelBufferSupport = false;
     fShaderPrecisionVaries = false;
@@ skipping 104 matching lines @@
     fImmediateFlush = options.fImmediateMode;
     fBufferMapThreshold = options.fBufferMapThreshold;
     fUseDrawInsteadOfPartialRenderTargetWrite = options.fUseDrawInsteadOfPartialRenderTargetWrite;
     fUseDrawInsteadOfAllRenderTargetWrites = false;
     fAvoidInstancedDrawsToFPTargets = false;
 
     fPreferVRAMUseOverFlushes = true;
 }
 
 void GrCaps::applyOptionsOverrides(const GrContextOptions& options) {
+    this->onApplyOptionsOverrides(options);
     fMaxTextureSize = SkTMin(fMaxTextureSize, options.fMaxTextureSizeOverride);
     // If the max tile override is zero, it means we should use the max texture size.
     if (!options.fMaxTileSizeOverride || options.fMaxTileSizeOverride > fMaxTextureSize) {
         fMaxTileSize = fMaxTextureSize;
     } else {
         fMaxTileSize = options.fMaxTileSizeOverride;
     }
-    this->onApplyOptionsOverrides(options);
+    if (fMaxWindowRectangles > GrWindowRectangles::kMaxWindows) {
+        fMaxWindowRectangles = GrWindowRectangles::kMaxWindows;

[csmartdalton, 2016/08/17 18:24:06]

We still cap. The cap just got moved here instead. (To the platform-independent
part. i.e. this will cap vulkan too)

kMaxWindows is 16. But I agree your suggestion of 8 makes more sense. Lets drop
to 8 and always increase later if needed.

+    }
 }
 
 static SkString map_flags_to_string(uint32_t flags) {
     SkString str;
     if (GrCaps::kNone_MapFlags == flags) {
         str = "none";
     } else {
         SkASSERT(GrCaps::kCanMap_MapFlag & flags);
         SkDEBUGCODE(flags &= ~GrCaps::kCanMap_MapFlag);
         str = "can_map";
@@ skipping 129 matching lines @@
 
     for (size_t i = 1; i < SK_ARRAY_COUNT(kConfigNames); ++i)  {
         GrPixelConfig config = static_cast<GrPixelConfig>(i);
         r.appendf("%s is uploadable to a texture: %s\n",
                   kConfigNames[i],
                   gNY[this->isConfigTexturable(config)]);
     }
 
     return r;
 }