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

cc/output/shader.h

 // Copyright 2011 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.
 
 #ifndef CC_OUTPUT_SHADER_H_
 #define CC_OUTPUT_SHADER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "cc/base/cc_export.h"
+#include "third_party/skia/include/core/SkXfermode.h"
 
 namespace gfx {
 class Point;
 class Size;
 }
 
 namespace gpu {
 namespace gles2 {
 class GLES2Interface;
 }
@@ skipping 250 matching lines @@
   int matrix_location() const { return matrix_location_; }
   int tex_matrix_location() const { return tex_matrix_location_; }
 
  private:
   int matrix_location_;
   int tex_matrix_location_;
 
   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_; }
+
+  SkXfermode::Mode blend_mode() const { return blend_mode_; }
+  bool is_default_blend_mode() const {
+    return blend_mode_ == SkXfermode::kSrcOver_Mode;
+  }
+  inline static bool is_blend_mode_supported(SkXfermode::Mode blend_mode);
+
+  void SetBlendMode(SkXfermode::Mode blend_mode);
+
+ protected:
+  FragmentTexBlendMode();
+
+  std::string SetBlendModeFunctions(std::string shader_string) const;
+
+  int backdrop_location_;
+  int backdrop_rect_location_;
+
+ private:
+  SkXfermode::Mode blend_mode_;
+
+  std::string GetHelperFunctions() const;
+  std::string GetMainBlendingCode() const;
+};
+
+class FragmentTexAlphaBinding : public FragmentTexBlendMode {
  public:
   FragmentTexAlphaBinding();
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return alpha_location_; }
   int fragment_tex_transform_location() const { return -1; }
   int sampler_location() const { return sampler_location_; }
 
  private:
   int sampler_location_;
   int alpha_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentTexAlphaBinding);
 };
 
-class FragmentTexColorMatrixAlphaBinding {
+class FragmentTexColorMatrixAlphaBinding : public FragmentTexBlendMode {
  public:
     FragmentTexColorMatrixAlphaBinding();
 
     void Init(gpu::gles2::GLES2Interface* context,
               unsigned program,
               int* base_uniform_index);
     int alpha_location() const { return alpha_location_; }
     int color_matrix_location() const { return color_matrix_location_; }
     int color_offset_location() const { return color_offset_location_; }
     int fragment_tex_transform_location() const { return -1; }
     int sampler_location() const { return sampler_location_; }
 
  private:
     int sampler_location_;
     int alpha_location_;
     int color_matrix_location_;
     int color_offset_location_;
 };
 
-class FragmentTexOpaqueBinding {
+class FragmentTexOpaqueBinding : public FragmentTexBlendMode {
  public:
   FragmentTexOpaqueBinding();
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return -1; }
   int fragment_tex_transform_location() const { return -1; }
   int background_color_location() const { return -1; }
   int sampler_location() const { return sampler_location_; }
 
  private:
   int sampler_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentTexOpaqueBinding);
 };
 
-class FragmentTexBackgroundBinding {
+class FragmentTexBackgroundBinding : public FragmentTexBlendMode {
  public:
   FragmentTexBackgroundBinding();
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int background_color_location() const { return background_color_location_; }
   int sampler_location() const { return sampler_location_; }
 
  private:
@@ skipping 61 matching lines @@
       TexCoordPrecision precision, SamplerType sampler) const;
 };
 
 // Swizzles the red and blue component of sampled texel without alpha.
 class FragmentShaderRGBATexSwizzleOpaque : public FragmentTexOpaqueBinding {
  public:
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 };
 
-class FragmentShaderRGBATexAlphaAA {
+class FragmentShaderRGBATexAlphaAA : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaAA();
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   int alpha_location() const { return alpha_location_; }
   int sampler_location() const { return sampler_location_; }
 
  private:
   int sampler_location_;
   int alpha_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderRGBATexAlphaAA);
 };
 
-class FragmentTexClampAlphaAABinding {
+class FragmentTexClampAlphaAABinding : public FragmentTexBlendMode {
  public:
   FragmentTexClampAlphaAABinding();
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return alpha_location_; }
   int sampler_location() const { return sampler_location_; }
   int fragment_tex_transform_location() const {
     return fragment_tex_transform_location_;
@@ skipping 15 matching lines @@
 };
 
 // Swizzles the red and blue component of sampled texel.
 class FragmentShaderRGBATexClampSwizzleAlphaAA
     : public FragmentTexClampAlphaAABinding {
  public:
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 };
 
-class FragmentShaderRGBATexAlphaMask {
+class FragmentShaderRGBATexAlphaMask : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaMask();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return alpha_location_; }
   int sampler_location() const { return sampler_location_; }
   int mask_sampler_location() const { return mask_sampler_location_; }
   int mask_tex_coord_scale_location() const {
     return mask_tex_coord_scale_location_;
   }
   int mask_tex_coord_offset_location() const {
     return mask_tex_coord_offset_location_;
   }
 
  private:
   int sampler_location_;
   int mask_sampler_location_;
   int alpha_location_;
   int mask_tex_coord_scale_location_;
   int mask_tex_coord_offset_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderRGBATexAlphaMask);
 };
 
-class FragmentShaderRGBATexAlphaMaskAA {
+class FragmentShaderRGBATexAlphaMaskAA : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaMaskAA();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return alpha_location_; }
   int sampler_location() const { return sampler_location_; }
   int mask_sampler_location() const { return mask_sampler_location_; }
   int mask_tex_coord_scale_location() const {
     return mask_tex_coord_scale_location_;
   }
   int mask_tex_coord_offset_location() const {
     return mask_tex_coord_offset_location_;
   }
 
  private:
   int sampler_location_;
   int mask_sampler_location_;
   int alpha_location_;
   int mask_tex_coord_scale_location_;
   int mask_tex_coord_offset_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderRGBATexAlphaMaskAA);
 };
 
-class FragmentShaderRGBATexAlphaMaskColorMatrixAA {
+class FragmentShaderRGBATexAlphaMaskColorMatrixAA
+    : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaMaskColorMatrixAA();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return alpha_location_; }
   int sampler_location() const { return sampler_location_; }
@@ skipping 10 matching lines @@
  private:
   int sampler_location_;
   int mask_sampler_location_;
   int alpha_location_;
   int mask_tex_coord_scale_location_;
   int mask_tex_coord_offset_location_;
   int color_matrix_location_;
   int color_offset_location_;
 };
 
-class FragmentShaderRGBATexAlphaColorMatrixAA {
+class FragmentShaderRGBATexAlphaColorMatrixAA : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaColorMatrixAA();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return alpha_location_; }
   int sampler_location() const { return sampler_location_; }
   int color_matrix_location() const { return color_matrix_location_; }
   int color_offset_location() const { return color_offset_location_; }
 
  private:
   int sampler_location_;
   int alpha_location_;
   int color_matrix_location_;
   int color_offset_location_;
 };
 
-class FragmentShaderRGBATexAlphaMaskColorMatrix {
+class FragmentShaderRGBATexAlphaMaskColorMatrix : public FragmentTexBlendMode {
  public:
   FragmentShaderRGBATexAlphaMaskColorMatrix();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return alpha_location_; }
   int sampler_location() const { return sampler_location_; }
@@ skipping 10 matching lines @@
  private:
   int sampler_location_;
   int mask_sampler_location_;
   int alpha_location_;
   int mask_tex_coord_scale_location_;
   int mask_tex_coord_offset_location_;
   int color_matrix_location_;
   int color_offset_location_;
 };
 
-class FragmentShaderYUVVideo {
+class FragmentShaderYUVVideo : public FragmentTexBlendMode {
  public:
   FragmentShaderYUVVideo();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int y_texture_location() const { return y_texture_location_; }
   int u_texture_location() const { return u_texture_location_; }
   int v_texture_location() const { return v_texture_location_; }
   int alpha_location() const { return alpha_location_; }
   int yuv_matrix_location() const { return yuv_matrix_location_; }
   int yuv_adj_location() const { return yuv_adj_location_; }
 
  private:
   int y_texture_location_;
   int u_texture_location_;
   int v_texture_location_;
   int alpha_location_;
   int yuv_matrix_location_;
   int yuv_adj_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderYUVVideo);
 };
 
-
-class FragmentShaderYUVAVideo {
+class FragmentShaderYUVAVideo : public FragmentTexBlendMode {
  public:
   FragmentShaderYUVAVideo();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
 
   int y_texture_location() const { return y_texture_location_; }
   int u_texture_location() const { return u_texture_location_; }
   int v_texture_location() const { return v_texture_location_; }
   int a_texture_location() const { return a_texture_location_; }
   int alpha_location() const { return alpha_location_; }
   int yuv_matrix_location() const { return yuv_matrix_location_; }
   int yuv_adj_location() const { return yuv_adj_location_; }
 
  private:
   int y_texture_location_;
   int u_texture_location_;
   int v_texture_location_;
   int a_texture_location_;
   int alpha_location_;
   int yuv_matrix_location_;
   int yuv_adj_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderYUVAVideo);
 };
 
-class FragmentShaderColor {
+class FragmentShaderColor : public FragmentTexBlendMode {
  public:
   FragmentShaderColor();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int color_location() const { return color_location_; }
 
  private:
   int color_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderColor);
 };
 
-class FragmentShaderColorAA {
+class FragmentShaderColorAA : public FragmentTexBlendMode {
  public:
   FragmentShaderColorAA();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int color_location() const { return color_location_; }
 
  private:
   int color_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderColorAA);
 };
 
-class FragmentShaderCheckerboard {
+class FragmentShaderCheckerboard : public FragmentTexBlendMode {
  public:
   FragmentShaderCheckerboard();
   std::string GetShaderString(
       TexCoordPrecision precision, SamplerType sampler) const;
 
   void Init(gpu::gles2::GLES2Interface* context,
             unsigned program,
             int* base_uniform_index);
   int alpha_location() const { return alpha_location_; }
   int tex_transform_location() const { return tex_transform_location_; }
   int frequency_location() const { return frequency_location_; }
   int color_location() const { return color_location_; }
 
  private:
   int alpha_location_;
   int tex_transform_location_;
   int frequency_location_;
   int color_location_;
 
   DISALLOW_COPY_AND_ASSIGN(FragmentShaderCheckerboard);
 };
 
 }  // namespace cc
 
 #endif  // CC_OUTPUT_SHADER_H_