Implement mix-blend-mode in GL renderer using shaders.

This implementation brings in several improvements for blending:
- it's done faster, due to reducing the number of readbacks.
- the backdrop doesn't suffer any transformation, so the result is more
  correct.
- the results are similar to the ones obtained using the software paths.
- blending is always applied after filters, even when the filters
  can be expressed using a color matrix.

The initial experiment: https://codereview.chromium.org/555133002/.

BUG=243223

Review URL: https://codereview.chromium.org/658483003

Cr-Commit-Position: refs/heads/master@{#300657}

cc/layers/delegated_renderer_layer_impl_unittest.cc

@@ -1416,7 +1416,12 @@ TEST_F(DelegatedRendererLayerImplTest, Occlusion) {
                                         pass1_id,
                                         gfx::Rect(layer_size),
                                         gfx::Transform());
-  AddRenderPassQuad(pass1, pass2, 0, FilterOperations(), transform);
+  AddRenderPassQuad(pass1,
+                    pass2,
+                    0,
+                    FilterOperations(),
+                    transform,
+                    SkXfermode::kSrcOver_Mode);
   delegated_renderer_layer_impl->SetFrameDataForRenderPasses(
       1.f, &delegated_render_passes);
 

cc/output/gl_renderer.h

@@ -153,7 +153,8 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
   gfx::Rect GetBackdropBoundingBoxForRenderPassQuad(
       DrawingFrame* frame,
       const RenderPassDrawQuad* quad,
-      const gfx::Transform& contents_device_transform);
+      const gfx::Transform& contents_device_transform,
+      bool use_aa);
   scoped_ptr<ScopedResource> GetBackdropTexture(const gfx::Rect& bounding_rect);
 
   static bool ShouldApplyBackgroundFilters(DrawingFrame* frame,
@@ -166,7 +167,6 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
       DrawingFrame* frame,
       const RenderPassDrawQuad* quad,
       const gfx::Transform& contents_device_transform_inverse,
-      ScopedResource* background_texture,
       skia::RefPtr<SkImage> backdrop_bitmap,
       const gfx::Rect& backdrop_bounding_rect);
 
@@ -328,22 +328,28 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
 
   const TileCheckerboardProgram* GetTileCheckerboardProgram();
 
-  const RenderPassProgram* GetRenderPassProgram(
-      TexCoordPrecision precision);
-  const RenderPassProgramAA* GetRenderPassProgramAA(
-      TexCoordPrecision precision);
+  const RenderPassProgram* GetRenderPassProgram(TexCoordPrecision precision,
+                                                BlendMode blend_mode);
+  const RenderPassProgramAA* GetRenderPassProgramAA(TexCoordPrecision precision,
+                                                    BlendMode blend_mode);
   const RenderPassMaskProgram* GetRenderPassMaskProgram(
-      TexCoordPrecision precision);
+      TexCoordPrecision precision,
+      BlendMode blend_mode);
   const RenderPassMaskProgramAA* GetRenderPassMaskProgramAA(
-      TexCoordPrecision precision);
+      TexCoordPrecision precision,
+      BlendMode blend_mode);
   const RenderPassColorMatrixProgram* GetRenderPassColorMatrixProgram(
-      TexCoordPrecision precision);
+      TexCoordPrecision precision,
+      BlendMode blend_mode);
   const RenderPassColorMatrixProgramAA* GetRenderPassColorMatrixProgramAA(
-      TexCoordPrecision precision);
+      TexCoordPrecision precision,
+      BlendMode blend_mode);
   const RenderPassMaskColorMatrixProgram* GetRenderPassMaskColorMatrixProgram(
-      TexCoordPrecision precision);
+      TexCoordPrecision precision,
+      BlendMode blend_mode);
   const RenderPassMaskColorMatrixProgramAA*
-      GetRenderPassMaskColorMatrixProgramAA(TexCoordPrecision precision);
+  GetRenderPassMaskColorMatrixProgramAA(TexCoordPrecision precision,
+                                        BlendMode blend_mode);
 
   const TextureProgram* GetTextureProgram(
       TexCoordPrecision precision);
@@ -388,18 +394,21 @@ class CC_EXPORT GLRenderer : public DirectRenderer {
       nonpremultiplied_texture_background_program_[NumTexCoordPrecisions];
   TextureProgram texture_io_surface_program_[NumTexCoordPrecisions];
 
-  RenderPassProgram render_pass_program_[NumTexCoordPrecisions];
-  RenderPassProgramAA render_pass_program_aa_[NumTexCoordPrecisions];
-  RenderPassMaskProgram render_pass_mask_program_[NumTexCoordPrecisions];
-  RenderPassMaskProgramAA render_pass_mask_program_aa_[NumTexCoordPrecisions];
+  RenderPassProgram render_pass_program_[NumTexCoordPrecisions][NumBlendModes];
+  RenderPassProgramAA
+      render_pass_program_aa_[NumTexCoordPrecisions][NumBlendModes];
+  RenderPassMaskProgram
+      render_pass_mask_program_[NumTexCoordPrecisions][NumBlendModes];
+  RenderPassMaskProgramAA
+      render_pass_mask_program_aa_[NumTexCoordPrecisions][NumBlendModes];
   RenderPassColorMatrixProgram
-      render_pass_color_matrix_program_[NumTexCoordPrecisions];
-  RenderPassColorMatrixProgramAA
-      render_pass_color_matrix_program_aa_[NumTexCoordPrecisions];
-  RenderPassMaskColorMatrixProgram
-      render_pass_mask_color_matrix_program_[NumTexCoordPrecisions];
-  RenderPassMaskColorMatrixProgramAA
-      render_pass_mask_color_matrix_program_aa_[NumTexCoordPrecisions];
+      render_pass_color_matrix_program_[NumTexCoordPrecisions][NumBlendModes];
+  RenderPassColorMatrixProgramAA render_pass_color_matrix_program_aa_
+      [NumTexCoordPrecisions][NumBlendModes];
+  RenderPassMaskColorMatrixProgram render_pass_mask_color_matrix_program_
+      [NumTexCoordPrecisions][NumBlendModes];
+  RenderPassMaskColorMatrixProgramAA render_pass_mask_color_matrix_program_aa_
+      [NumTexCoordPrecisions][NumBlendModes];
 
   VideoYUVProgram video_yuv_program_[NumTexCoordPrecisions];
   VideoYUVAProgram video_yuva_program_[NumTexCoordPrecisions];

cc/output/program_binding.h

@@ -58,13 +58,16 @@ class ProgramBinding : public ProgramBindingBase {
 
   void Initialize(ContextProvider* context_provider,
                   TexCoordPrecision precision,
-                  SamplerType sampler) {
+                  SamplerType sampler,
+                  BlendMode blend_mode = BlendModeNormal) {
     DCHECK(context_provider);
     DCHECK(!initialized_);
 
     if (context_provider->IsContextLost())
       return;
 
+    fragment_shader_.set_blend_mode(blend_mode);
+
     if (!ProgramBindingBase::Init(
             context_provider->ContextGL(),
             vertex_shader_.GetShaderString(),

cc/output/shader.h

@@ -38,6 +38,25 @@ enum SamplerType {
   NumSamplerTypes = 4
 };
 
+enum BlendMode {
+  BlendModeNormal,
+  BlendModeOverlay,
+  BlendModeDarken,
+  BlendModeLighten,
+  BlendModeColorDodge,
+  BlendModeColorBurn,
+  BlendModeHardLight,
+  BlendModeSoftLight,
+  BlendModeDifference,
+  BlendModeExclusion,
+  BlendModeMultiply,
+  BlendModeHue,
+  BlendModeSaturation,
+  BlendModeColor,
+  BlendModeLuminosity,
+  NumBlendModes
+};
+
 // Note: The highp_threshold_cache must be provided by the caller to make
 // the caching multi-thread/context safe in an easy low-overhead manner.
 // The caller must make sure to clear highp_threshold_cache to 0, so it can be
@@ -279,7 +298,32 @@ class VertexShaderVideoTransform {
   DISALLOW_COPY_AND_ASSIGN(VertexShaderVideoTransform);
 };
 
-class FragmentTexAlphaBinding {
+class FragmentTexBlendMode {
+ public:
+  int backdrop_location() const { return backdrop_location_; }
+  int backdrop_rect_location() const { return backdrop_rect_location_; }
+
+  BlendMode blend_mode() const { return blend_mode_; }
+  void set_blend_mode(BlendMode blend_mode) { blend_mode_ = blend_mode; }
+  bool is_default_blend_mode() const { return blend_mode_ == BlendModeNormal; }
+
+ protected:
+  FragmentTexBlendMode();
+
+  std::string SetBlendModeFunctions(std::string shader_string) const;
+
+  int backdrop_location_;
+  int backdrop_rect_location_;
+
+ private:
+  BlendMode blend_mode_;
+
+  std::string GetHelperFunctions() const;
+  std::string GetBlendFunction() const;
+  std::string GetBlendFunctionBodyForRGB() const;
+};
+
+class FragmentTexAlphaBinding : public FragmentTexBlendMode {
  public:
   FragmentTexAlphaBinding();
 
@@ -297,7 +341,7 @@ class FragmentTexAlphaBinding {
   DISALLOW_COPY_AND_ASSIGN(FragmentTexAlphaBinding);
 };
 
-class FragmentTexColorMatrixAlphaBinding {
+class FragmentTexColorMatrixAlphaBinding : public FragmentTexBlendMode {
  public:
     FragmentTexColorMatrixAlphaBinding();
 
@@ -317,7 +361,7 @@ class FragmentTexColorMatrixAlphaBinding {
     int color_offset_location_;
 };
 
-class FragmentTexOpaqueBinding {
+class FragmentTexOpaqueBinding : public FragmentTexBlendMode {
  public:
   FragmentTexOpaqueBinding();
 
@@ -335,7 +379,7 @@ class FragmentTexOpaqueBinding {
   DISALLOW_COPY_AND_ASSIGN(FragmentTexOpaqueBinding);
 };
 
-class FragmentTexBackgroundBinding {
+class FragmentTexBackgroundBinding : public FragmentTexBlendMode {
  public:
   FragmentTexBackgroundBinding();
 
@@ -417,7 +461,7 @@ class FragmentShaderRGBATexSwizzleOpaque : public FragmentTexOpaqueBinding {
       TexCoordPrecision precision, SamplerType sampler) const;
 };
 
-class FragmentShaderRGBATexAlphaAA {
+class FragmentShaderRGBATexAlphaAA : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaAA();
 
@@ -437,7 +481,7 @@ class FragmentShaderRGBATexAlphaAA {
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderRGBATexAlphaAA);
 };
 
-class FragmentTexClampAlphaAABinding {
+class FragmentTexClampAlphaAABinding : public FragmentTexBlendMode {
  public:
   FragmentTexClampAlphaAABinding();
 
@@ -473,7 +517,7 @@ class FragmentShaderRGBATexClampSwizzleAlphaAA
       TexCoordPrecision precision, SamplerType sampler) const;
 };
 
-class FragmentShaderRGBATexAlphaMask {
+class FragmentShaderRGBATexAlphaMask : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaMask();
   std::string GetShaderString(
@@ -502,7 +546,7 @@ class FragmentShaderRGBATexAlphaMask {
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderRGBATexAlphaMask);
 };
 
-class FragmentShaderRGBATexAlphaMaskAA {
+class FragmentShaderRGBATexAlphaMaskAA : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaMaskAA();
   std::string GetShaderString(
@@ -531,7 +575,8 @@ class FragmentShaderRGBATexAlphaMaskAA {
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderRGBATexAlphaMaskAA);
 };
 
-class FragmentShaderRGBATexAlphaMaskColorMatrixAA {
+class FragmentShaderRGBATexAlphaMaskColorMatrixAA
+    : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaMaskColorMatrixAA();
   std::string GetShaderString(
@@ -562,7 +607,7 @@ class FragmentShaderRGBATexAlphaMaskColorMatrixAA {
   int color_offset_location_;
 };
 
-class FragmentShaderRGBATexAlphaColorMatrixAA {
+class FragmentShaderRGBATexAlphaColorMatrixAA : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaColorMatrixAA();
   std::string GetShaderString(
@@ -583,7 +628,7 @@ class FragmentShaderRGBATexAlphaColorMatrixAA {
   int color_offset_location_;
 };
 
-class FragmentShaderRGBATexAlphaMaskColorMatrix {
+class FragmentShaderRGBATexAlphaMaskColorMatrix : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaMaskColorMatrix();
   std::string GetShaderString(
@@ -614,7 +659,7 @@ class FragmentShaderRGBATexAlphaMaskColorMatrix {
   int color_offset_location_;
 };
 
-class FragmentShaderYUVVideo {
+class FragmentShaderYUVVideo : public FragmentTexBlendMode {
  public:
   FragmentShaderYUVVideo();
   std::string GetShaderString(
@@ -641,8 +686,7 @@ class FragmentShaderYUVVideo {
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderYUVVideo);
 };
 
-
-class FragmentShaderYUVAVideo {
+class FragmentShaderYUVAVideo : public FragmentTexBlendMode {
  public:
   FragmentShaderYUVAVideo();
   std::string GetShaderString(
@@ -672,7 +716,7 @@ class FragmentShaderYUVAVideo {
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderYUVAVideo);
 };
 
-class FragmentShaderColor {
+class FragmentShaderColor : public FragmentTexBlendMode {
  public:
   FragmentShaderColor();
   std::string GetShaderString(
@@ -689,7 +733,7 @@ class FragmentShaderColor {
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderColor);
 };
 
-class FragmentShaderColorAA {
+class FragmentShaderColorAA : public FragmentTexBlendMode {
  public:
   FragmentShaderColorAA();
   std::string GetShaderString(
@@ -706,7 +750,7 @@ class FragmentShaderColorAA {
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderColorAA);
 };
 
-class FragmentShaderCheckerboard {
+class FragmentShaderCheckerboard : public FragmentTexBlendMode {
  public:
   FragmentShaderCheckerboard();
   std::string GetShaderString(

cc/output/software_renderer.cc

@@ -239,14 +239,16 @@ void SoftwareRenderer::DoDrawQuad(DrawingFrame* frame, const DrawQuad* quad) {
   current_canvas_->setMatrix(sk_device_matrix);
 
   current_paint_.reset();
-  if (!IsScaleAndIntegerTranslate(sk_device_matrix)) {
+  if (settings_->force_antialiasing ||
+      !IsScaleAndIntegerTranslate(sk_device_matrix)) {
     // TODO(danakj): Until we can enable AA only on exterior edges of the
     // layer, disable AA if any interior edges are present. crbug.com/248175
     bool all_four_edges_are_exterior = quad->IsTopEdge() &&
                                        quad->IsLeftEdge() &&
                                        quad->IsBottomEdge() &&
                                        quad->IsRightEdge();
-    if (settings_->allow_antialiasing && all_four_edges_are_exterior)
+    if (settings_->allow_antialiasing &&
+        (settings_->force_antialiasing || all_four_edges_are_exterior))
       current_paint_.setAntiAlias(true);
     current_paint_.setFilterLevel(SkPaint::kLow_FilterLevel);
   }

cc/test/render_pass_test_utils.cc

@@ -111,7 +111,8 @@ void AddRenderPassQuad(TestRenderPass* to_pass,
                        TestRenderPass* contributing_pass,
                        ResourceProvider::ResourceId mask_resource_id,
                        const FilterOperations& filters,
-                       gfx::Transform transform) {
+                       gfx::Transform transform,
+                       SkXfermode::Mode blend_mode) {
   gfx::Rect output_rect = contributing_pass->output_rect;
   SharedQuadState* shared_state = to_pass->CreateAndAppendSharedQuadState();
   shared_state->SetAll(transform,
@@ -120,7 +121,7 @@ void AddRenderPassQuad(TestRenderPass* to_pass,
                        output_rect,
                        false,
                        1,
-                       SkXfermode::kSrcOver_Mode,
+                       blend_mode,
                        0);
   RenderPassDrawQuad* quad =
       to_pass->CreateAndAppendDrawQuad<RenderPassDrawQuad>();

cc/test/render_pass_test_utils.h

@@ -53,7 +53,8 @@ void AddRenderPassQuad(TestRenderPass* toPass,
                        TestRenderPass* contributing_pass,
                        ResourceProvider::ResourceId mask_resource_id,
                        const FilterOperations& filters,
-                       gfx::Transform transform);
+                       gfx::Transform transform,
+                       SkXfermode::Mode blend_mode);
 
 }  // namespace cc
 

cc/trees/layer_tree_settings.cc

@@ -15,6 +15,7 @@ namespace cc {
 LayerTreeSettings::LayerTreeSettings()
     : impl_side_painting(false),
       allow_antialiasing(true),
+      force_antialiasing(false),
       throttle_frame_production(true),
       single_thread_proxy_scheduler(true),
       begin_frame_scheduling_enabled(false),

cc/trees/layer_tree_settings.h

@@ -20,6 +20,7 @@ class CC_EXPORT LayerTreeSettings {
 
   bool impl_side_painting;
   bool allow_antialiasing;
+  bool force_antialiasing;
   bool throttle_frame_production;
   bool single_thread_proxy_scheduler;
   bool begin_frame_scheduling_enabled;