Add support for all blendmodes if we have GL_KHR_blend_equation_advanced.

cc/output/gl_renderer.cc

Index: cc/output/gl_renderer.cc
diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index ac449a46f5df84bc66ffe091b6470f8c6a394cb9..da8996a83d2d876bce38fe94ccb7670a75220d77 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -339,6 +339,7 @@ GLRenderer::GLRenderer(RendererClient* client,
 
   use_sync_query_ = context_caps.gpu.sync_query;
   use_blend_minmax_ = context_caps.gpu.blend_minmax;
+  use_blend_equation_advanced_ = context_caps.gpu.blend_equation_advanced;
 
   InitializeSharedObjects();
 }
@@ -700,20 +701,77 @@ static skia::RefPtr<SkImage> ApplyImageFilter(
 }
 
 bool GLRenderer::CanApplyBlendModeUsingBlendFunc(SkXfermode::Mode blend_mode) {
-  return (use_blend_minmax_ && blend_mode == SkXfermode::kLighten_Mode) ||
-         blend_mode == SkXfermode::kScreen_Mode ||
-         blend_mode == SkXfermode::kSrcOver_Mode;
+  return use_blend_equation_advanced_ ||
+          (use_blend_minmax_ && blend_mode == SkXfermode::kLighten_Mode) ||
+          blend_mode == SkXfermode::kScreen_Mode ||
+          blend_mode == SkXfermode::kSrcOver_Mode;
 }
 
 void GLRenderer::ApplyBlendModeUsingBlendFunc(SkXfermode::Mode blend_mode) {
   DCHECK(CanApplyBlendModeUsingBlendFunc(blend_mode));
 
   // Any modes set here must be reset in RestoreBlendFuncToDefault
-  if (blend_mode == SkXfermode::kScreen_Mode) {
-    GLC(gl_, gl_->BlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ONE));
-  } else if (blend_mode == SkXfermode::kLighten_Mode) {
-    GLC(gl_, gl_->BlendFunc(GL_ONE, GL_ONE));
-    GLC(gl_, gl_->BlendEquation(GL_MAX_EXT));
+  if (use_blend_equation_advanced_) {
+      GLenum equation = GL_SRC_OVER_NV;
+
+      switch (blend_mode) {
+      case SkXfermode::kScreen_Mode:

[piman, 2014/10/16 20:13:28]

nit: indent style (run git cl format?)

[Erik Dahlström (inactive), 2014/10/17 15:33:17]

Done.

+          equation = GL_SCREEN_NV;
+          break;
+      case SkXfermode::kOverlay_Mode:
+          equation = GL_OVERLAY_NV;
+          break;
+      case SkXfermode::kDarken_Mode:
+          equation = GL_DARKEN_NV;
+          break;
+      case SkXfermode::kLighten_Mode:
+          equation = GL_LIGHTEN_NV;
+          break;
+      case SkXfermode::kColorDodge_Mode:
+          equation = GL_COLORDODGE_NV;
+          break;
+      case SkXfermode::kColorBurn_Mode:
+          equation = GL_COLORBURN_NV;
+          break;
+      case SkXfermode::kHardLight_Mode:
+          equation = GL_HARDLIGHT_NV;
+          break;
+      case SkXfermode::kSoftLight_Mode:
+          equation = GL_SOFTLIGHT_NV;
+          break;
+      case SkXfermode::kDifference_Mode:
+          equation = GL_DIFFERENCE_NV;
+          break;
+      case SkXfermode::kExclusion_Mode:
+          equation = GL_EXCLUSION_NV;
+          break;
+      case SkXfermode::kMultiply_Mode:
+          equation = GL_MULTIPLY_NV;
+          break;
+      case SkXfermode::kHue_Mode:
+          equation = GL_HSL_HUE_NV;
+          break;
+      case SkXfermode::kSaturation_Mode:
+          equation = GL_HSL_SATURATION_NV;
+          break;
+      case SkXfermode::kColor_Mode:
+          equation = GL_HSL_COLOR_NV;
+          break;
+      case SkXfermode::kLuminosity_Mode:
+          equation = GL_HSL_LUMINOSITY_NV;
+          break;
+      default:
+          return;
+      }
+
+      GLC(gl_, gl_->BlendEquation(equation));
+  } else {
+      if (blend_mode == SkXfermode::kScreen_Mode) {
+        GLC(gl_, gl_->BlendFunc(GL_ONE_MINUS_DST_COLOR, GL_ONE));
+      } else if (blend_mode == SkXfermode::kLighten_Mode) {
+        GLC(gl_, gl_->BlendFunc(GL_ONE, GL_ONE));
+        GLC(gl_, gl_->BlendEquation(GL_MAX_EXT));
+      }
   }
 }
 
@@ -721,10 +779,14 @@ void GLRenderer::RestoreBlendFuncToDefault(SkXfermode::Mode blend_mode) {
   if (blend_mode == SkXfermode::kSrcOver_Mode)
     return;
 
-  GLC(gl_, gl_->BlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA));
+  if (use_blend_equation_advanced_) {
+      GLC(gl_, gl_->BlendEquation(GL_FUNC_ADD));
+  } else {
+      GLC(gl_, gl_->BlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA));
 
-  if (blend_mode == SkXfermode::kLighten_Mode)
-    GLC(gl_, gl_->BlendEquation(GL_FUNC_ADD));
+      if (blend_mode == SkXfermode::kLighten_Mode)
+          GLC(gl_, gl_->BlendEquation(GL_FUNC_ADD));
+  }
 }
 
 static skia::RefPtr<SkImage> ApplyBlendModeWithBackdrop(
@@ -1194,8 +1256,12 @@ void GLRenderer::DrawRenderPassQuad(DrawingFrame* frame,
               contents_resource_lock->target());
   }
 
-  if (CanApplyBlendModeUsingBlendFunc(blend_mode))
-    ApplyBlendModeUsingBlendFunc(blend_mode);
+  if (CanApplyBlendModeUsingBlendFunc(blend_mode)) {
+      if (use_blend_equation_advanced_)
+          GLC(gl_, gl_->BlendBarrierNV());

[piman, 2014/10/16 20:13:29]

Is it worth skipping this if we have GL_*_blend_equation_advanced_coherent?

[Erik Dahlström (inactive), 2014/10/17 15:33:17]

Perhaps, my current card/driver setup doesn't support the coherent mode so I
can't test if that's better/faster.

+
+      ApplyBlendModeUsingBlendFunc(blend_mode);
+  }
 
   TexCoordPrecision tex_coord_precision = TexCoordPrecisionRequired(
       gl_,