[WIP Experiment] Implement mix-blend-mode in GLRenderer using shaders.

cc/output/program_binding.h

Index: cc/output/program_binding.h
diff --git a/cc/output/program_binding.h b/cc/output/program_binding.h
index 912329ef6bf548055ad6a07de577f12040af4936..fd889293ee1e351926a231533b2a24223fb76915 100644
--- a/cc/output/program_binding.h
+++ b/cc/output/program_binding.h
@@ -98,6 +98,56 @@ class ProgramBinding : public ProgramBindingBase {
   DISALLOW_COPY_AND_ASSIGN(ProgramBinding);
 };
 
+template <class VertexShader, class FragmentShader>
+class ProgramBindingWithBlendMode : public ProgramBindingBase {
+ public:
+  ProgramBindingWithBlendMode() {}
+
+  void Initialize(ContextProvider* context_provider,
+                  TexCoordPrecision precision,
+                  SamplerType sampler,
+                  SkXfermode::Mode blend_mode) {
+    DCHECK(context_provider);
+    DCHECK(!initialized_);
+
+    if (context_provider->IsContextLost())
+      return;
+
+    if (!ProgramBindingBase::Init(
+            context_provider->ContextGL(),
+            vertex_shader_.GetShaderString(),
+            fragment_shader_.GetShaderString(precision, sampler, blend_mode))) {
+      DCHECK(context_provider->IsContextLost());
+      return;
+    }
+
+    int base_uniform_index = 0;
+    vertex_shader_.Init(
+        context_provider->ContextGL(), program_, &base_uniform_index);
+    fragment_shader_.Init(context_provider->ContextGL(),
+                          program_,
+                          &base_uniform_index,
+                          blend_mode != SkXfermode::kSrcOver_Mode);
+
+    // Link after binding uniforms
+    if (!Link(context_provider->ContextGL())) {
+      DCHECK(context_provider->IsContextLost());
+      return;
+    }
+
+    initialized_ = true;
+  }
+
+  const VertexShader& vertex_shader() const { return vertex_shader_; }

[enne (OOO), 2014/09/24 22:07:56]

Why shadow the base class with these functions and member variables?

+  const FragmentShader& fragment_shader() const { return fragment_shader_; }
+
+ private:
+  VertexShader vertex_shader_;
+  FragmentShader fragment_shader_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProgramBindingWithBlendMode);
+};
+
 }  // namespace cc
 
 #endif  // CC_OUTPUT_PROGRAM_BINDING_H_