mix-blend-mode implementation for accelerated layers

cc/quads/shared_quad_state.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/quads/shared_quad_state.h"
 
 #include "base/values.h"
 #include "cc/base/math_util.h"
 #include "cc/debug/traced_value.h"
 
 namespace cc {
 
-SharedQuadState::SharedQuadState() : is_clipped(false), opacity(0.f) {}
+namespace {
+
+const char* BlendModeToString(SkXfermode::Mode blendMode) {
+  switch (blendMode) {
+  case SkXfermode::kMultiply_Mode:    return "multiply";
+  case SkXfermode::kScreen_Mode:      return "screen";
+  case SkXfermode::kOverlay_Mode:     return "overlay";
+  case SkXfermode::kDarken_Mode:      return "darken";
+  case SkXfermode::kLighten_Mode:     return "lighten";
+  case SkXfermode::kColorDodge_Mode:  return "color-dodge";
+  case SkXfermode::kColorBurn_Mode:   return "color-burn";
+  case SkXfermode::kHardLight_Mode:   return "hard-light";
+  case SkXfermode::kSoftLight_Mode:   return "soft-light";
+  case SkXfermode::kDifference_Mode:  return "difference";
+  case SkXfermode::kExclusion_Mode:   return "exclusion";
+  case SkXfermode::kHue_Mode:         return "hue";
+  case SkXfermode::kSaturation_Mode:  return "saturation";
+  case SkXfermode::kColor_Mode:       return "color";
+  case SkXfermode::kLuminosity_Mode:  return "luminosity";
+  default:                            return "normal";
+  }
+}
+
+}  // namespace
+
+SharedQuadState::SharedQuadState() : is_clipped(false),
+                                     opacity(0.f),
+                                     blend_mode(SkXfermode::kSrcOver_Mode) {}
 
 SharedQuadState::~SharedQuadState() {
   TRACE_EVENT_OBJECT_DELETED_WITH_ID(
       TRACE_DISABLED_BY_DEFAULT("cc.debug.quads"),
       "cc::SharedQuadState", this);
 }
 
 scoped_ptr<SharedQuadState> SharedQuadState::Create() {
   return make_scoped_ptr(new SharedQuadState);
 }
 
 scoped_ptr<SharedQuadState> SharedQuadState::Copy() const {
   return make_scoped_ptr(new SharedQuadState(*this));
 }
 
 void SharedQuadState::SetAll(
     const gfx::Transform& content_to_target_transform,
     gfx::Size content_bounds,
     gfx::Rect visible_content_rect,
     gfx::Rect clip_rect,
     bool is_clipped,
-    float opacity) {
+    float opacity,
+    SkXfermode::Mode blend_mode) {
   this->content_to_target_transform = content_to_target_transform;
   this->content_bounds = content_bounds;
   this->visible_content_rect = visible_content_rect;
   this->clip_rect = clip_rect;
   this->is_clipped = is_clipped;
   this->opacity = opacity;
+  this->blend_mode = blend_mode;
 }
 
 scoped_ptr<base::Value> SharedQuadState::AsValue() const {
   scoped_ptr<base::DictionaryValue> value(new base::DictionaryValue());
   value->Set("transform",
              MathUtil::AsValue(content_to_target_transform).release());
   value->Set("layer_content_bounds",
              MathUtil::AsValue(content_bounds).release());
   value->Set("layer_visible_content_rect",
              MathUtil::AsValue(visible_content_rect).release());
   value->SetBoolean("is_clipped", is_clipped);
   value->Set("clip_rect", MathUtil::AsValue(clip_rect).release());
   value->SetDouble("opacity", opacity);
+  value->SetString("blend_mode", BlendModeToString(blend_mode));
   TracedValue::MakeDictIntoImplicitSnapshotWithCategory(
       TRACE_DISABLED_BY_DEFAULT("cc.debug.quads"),
       value.get(), "cc::SharedQuadState", this);
   return value.PassAs<base::Value>();
 }
 
 }  // namespace cc