mix-blend-mode implementation for accelerated layers

cc/trees/layer_tree_host_pixeltest_blending.cc

Index: cc/trees/layer_tree_host_pixeltest_blending.cc
diff --git a/cc/trees/layer_tree_host_pixeltest_blending.cc b/cc/trees/layer_tree_host_pixeltest_blending.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1733e328b4631330964a6520617addef1159a9db
--- /dev/null
+++ b/cc/trees/layer_tree_host_pixeltest_blending.cc
@@ -0,0 +1,122 @@
+// Copyright 2013 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/layers/solid_color_layer.h"
+#include "cc/layers/texture_layer.h"
+#include "cc/test/layer_tree_pixel_test.h"
+
+#if !defined(OS_ANDROID)
+
+namespace cc {
+namespace {
+
+class LayerTreeHostBlendingPixelTest : public LayerTreePixelTest {};
+
+SkXfermode::Mode const blend_modes[] = {
+    SkXfermode::kSrcOver_Mode,   SkXfermode::kScreen_Mode,
+    SkXfermode::kOverlay_Mode,   SkXfermode::kDarken_Mode,
+    SkXfermode::kLighten_Mode,   SkXfermode::kColorDodge_Mode,
+    SkXfermode::kColorBurn_Mode, SkXfermode::kHardLight_Mode,
+    SkXfermode::kSoftLight_Mode, SkXfermode::kDifference_Mode,
+    SkXfermode::kExclusion_Mode, SkXfermode::kMultiply_Mode,
+    SkXfermode::kHue_Mode,       SkXfermode::kSaturation_Mode,
+    SkXfermode::kColor_Mode,     SkXfermode::kLuminosity_Mode};
+
+unsigned const blend_modes_count = arraysize(blend_modes);

[enne (OOO), 2013/11/01 18:49:02]

unsigned const => const int, here and elsewhere.  Chromium style is to only use
unsigned for bitmasks, object counts, and array indices.

Also, if you're making a const, it should be kConstStyle not hacker_style. 
(Sorry.)

[rosca, 2013/11/04 17:14:34]

Done.

+
+TEST_F(LayerTreeHostBlendingPixelTest, BlendingWithRoot) {
+  unsigned const lane_width = 15;
+  unsigned const lane_hight = blend_modes_count * lane_width;
+  unsigned const root_size = (blend_modes_count + 2) * lane_width;
+
+  scoped_refptr<SolidColorLayer> background =
+      CreateSolidColorLayer(gfx::Rect(root_size, root_size), kCSSOrange);
+
+  // Orange child layers will blend with the green background
+  for (unsigned i = 0; i < blend_modes_count; ++i) {

[enne (OOO), 2013/11/01 18:49:02]

I like these these tests a lot, thanks!

+    gfx::Rect child_rect(
+        (i + 1) * lane_width, lane_width, lane_width, lane_hight);
+    scoped_refptr<SolidColorLayer> orange =
+        CreateSolidColorLayer(child_rect, kCSSGreen);
+    background->AddChild(orange);
+    orange->SetBlendMode(blend_modes[i]);
+  }
+
+  RunPixelTest(GL_WITH_BITMAP,
+               background,
+               base::FilePath(FILE_PATH_LITERAL("blending_with_root.png")));
+}
+
+TEST_F(LayerTreeHostBlendingPixelTest, BlendingWithBackgroundFilter) {
+  unsigned const lane_width = 15;
+  unsigned const lane_hight = blend_modes_count * lane_width;
+  unsigned const root_size = (blend_modes_count + 2) * lane_width;
+
+  scoped_refptr<SolidColorLayer> background =
+      CreateSolidColorLayer(gfx::Rect(root_size, root_size), kCSSOrange);
+
+  // Orange child layers have a background filter set and they will blend with
+  // the green background
+  for (unsigned i = 0; i < blend_modes_count; ++i) {
+    gfx::Rect child_rect(
+        (i + 1) * lane_width, lane_width, lane_width, lane_hight);
+    scoped_refptr<SolidColorLayer> orange =
+        CreateSolidColorLayer(child_rect, kCSSGreen);
+    background->AddChild(orange);
+
+    FilterOperations filters;
+    filters.Append(FilterOperation::CreateGrayscaleFilter(.75));
+    orange->SetBackgroundFilters(filters);
+    orange->SetBlendMode(blend_modes[i]);
+  }
+
+  RunPixelTest(GL_WITH_BITMAP,
+               background,
+               base::FilePath(FILE_PATH_LITERAL("blending_and_filter.png")));
+}
+
+TEST_F(LayerTreeHostBlendingPixelTest, BlendingWithTransparent) {
+  unsigned const lane_width = 15;
+  unsigned const lane_hight = blend_modes_count * lane_width;

[enne (OOO), 2013/11/01 18:49:02]

hight => height

[rosca, 2013/11/04 17:14:34]

Done.

+  unsigned const root_size = (blend_modes_count + 2) * lane_width;
+
+  scoped_refptr<SolidColorLayer> root =
+      CreateSolidColorLayer(gfx::Rect(root_size, root_size), kCSSBrown);
+
+  SkBitmap bitmap;
+  bitmap.setConfig(SkBitmap::kARGB_8888_Config, root_size, root_size);
+  bitmap.allocPixels();
+  SkCanvas canvas(bitmap);
+
+  SkPaint paint;
+  paint.setColor(SK_ColorRED);
+  canvas.clear(SK_ColorTRANSPARENT);
+  gfx::Rect red_lane_quad(0, lane_width * 2, root_size, lane_width);
+  canvas.drawRect(SkRect::MakeXYWH(0, lane_width * 2, root_size, lane_width),
+                  paint);
+
+  scoped_refptr<TextureLayer> background =
+      CreateTextureLayer(gfx::Rect(root_size, root_size), bitmap);
+  root->AddChild(background);
+  background->SetIsRootForIsolatedGroup(true);
+
+  // Orange child layers will blend with the green background
+  for (unsigned i = 0; i < blend_modes_count; ++i) {
+    gfx::Rect child_rect(
+        (i + 1) * lane_width, lane_width, lane_width, lane_hight);
+    scoped_refptr<SolidColorLayer> orange =
+        CreateSolidColorLayer(child_rect, kCSSGreen);
+    background->AddChild(orange);
+    orange->SetBlendMode(blend_modes[i]);
+  }
+
+  RunPixelTest(GL_WITH_BITMAP,
+               root,
+               base::FilePath(FILE_PATH_LITERAL("blending_transparent.png")));
+}
+
+}  // namespace
+}  // namespace cc
+
+#endif  // OS_ANDROID