Revert 196423 "cc: Fix anti-aliasing of axis-aligned quads."

[Reason for revert: AxisAligned unit test is failing on some of the Mac bots.]

> cc: Fix anti-aliasing of axis-aligned quads.
> 
> Axis-aligned quads with edges not aligned to pixel boundaries
> are rendered incorrectly. These quads need anti-aliasing but
> current code that determines if anti-aliasing is needed thinks
> that no axis-aligned quads need it.
> 
> This fixes the problem by adding alignment to pixel boundaries
> as an additional requirement to avoid anti-aliasing.
> 
> BUG=169374
> TEST=GLRendererPixelTest.AxisAligned,GLRendererShaderTest.DrawSolidColorShad
> 
> Review URL: https://chromiumcodereview.appspot.com/12538005

TBR=reveman@chromium.org

Review URL: https://codereview.chromium.org/14465006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@196427 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 12 insertions, 128 deletions

diff --git a/cc/output/gl_renderer.cc b/cc/output/gl_renderer.cc
index 19b215b..cf7b64b 100644
--- a/cc/output/gl_renderer.cc
+++ b/cc/output/gl_renderer.cc
@@ -81,10 +81,6 @@ bool NeedsIOSurfaceReadbackWorkaround() {
 #endif
 }
 
-// Smallest unit that impact anti-aliasing output. We use this to
-// determine when anti-aliasing is unnecessary.
-const float kAntiAliasingEpsilon = 1.0f / 1024.0f;
-
 }  // anonymous namespace
 
 scoped_ptr<GLRenderer> GLRenderer::Create(RendererClient* client,
@@ -719,8 +715,7 @@ void GLRenderer::DrawRenderPassQuad(DrawingFrame* frame,
 
   // Use anti-aliasing programs only when necessary.
   bool use_aa = (!device_quad.IsRectilinear() ||
-                 !gfx::IsNearestRectWithinDistance(device_quad.BoundingBox(),
-                                                   kAntiAliasingEpsilon));
+                 !device_quad.BoundingBox().IsExpressibleAsRect());
   if (use_aa) {
     device_layer_bounds.InflateAntiAliasingDistance();
     device_layer_edges.InflateAntiAliasingDistance();
@@ -1016,11 +1011,11 @@ bool GLRenderer::SetupQuadForAntialiasing(
       device_transform, gfx::QuadF(quad->visibleContentRect()), &clipped);
   DCHECK(!clipped);
 
+  // TODO(reveman): Axis-aligned is not enough to avoid anti-aliasing.
+  // Bounding rectangle for quad also needs to be expressible as an integer
+  // rectangle. crbug.com/169374
   bool is_axis_aligned_in_target = device_layer_quad.IsRectilinear();
-  bool is_nearest_rect_within_epsilon = is_axis_aligned_in_target &&
-      gfx::IsNearestRectWithinDistance(device_layer_quad.BoundingBox(),
-                                       kAntiAliasingEpsilon);
-  bool use_aa = !clipped && !is_nearest_rect_within_epsilon && quad->IsEdge();
+  bool use_aa = !clipped && !is_axis_aligned_in_target && quad->IsEdge();
 
   if (!use_aa)
     return false;
@@ -1205,16 +1200,13 @@ void GLRenderer::DrawContentQuad(const DrawingFrame* frame,
   // is mapped to the unit square by the vertex shader and mapped
   // back to normalized texture coordinates by the fragment shader
   // after being clamped to 0-1 range.
-  float tex_clamp_x = std::min(
-      0.5f, 0.5f * clamp_tex_rect.width() - kAntiAliasingEpsilon);
-  float tex_clamp_y = std::min(
-      0.5f, 0.5f * clamp_tex_rect.height() - kAntiAliasingEpsilon);
-  float geom_clamp_x = std::min(
-      tex_clamp_x * tex_to_geom_scale_x,
-      0.5f * clamp_geom_rect.width() - kAntiAliasingEpsilon);
-  float geom_clamp_y = std::min(
-      tex_clamp_y * tex_to_geom_scale_y,
-      0.5f * clamp_geom_rect.height() - kAntiAliasingEpsilon);
+  const float epsilon = 1.0f / 1024.0f;
+  float tex_clamp_x = std::min(0.5f, 0.5f * clamp_tex_rect.width() - epsilon);
+  float tex_clamp_y = std::min(0.5f, 0.5f * clamp_tex_rect.height() - epsilon);
+  float geom_clamp_x = std::min(tex_clamp_x * tex_to_geom_scale_x,
+                                0.5f * clamp_geom_rect.width() - epsilon);
+  float geom_clamp_y = std::min(tex_clamp_y * tex_to_geom_scale_y,
+                                0.5f * clamp_geom_rect.height() - epsilon);
   clamp_geom_rect.Inset(geom_clamp_x, geom_clamp_y, geom_clamp_x, geom_clamp_y);
   clamp_tex_rect.Inset(tex_clamp_x, tex_clamp_y, tex_clamp_x, tex_clamp_y);
 
diff --git a/cc/output/gl_renderer_pixeltest.cc b/cc/output/gl_renderer_pixeltest.cc
index 8da1b24..064b78b 100644
--- a/cc/output/gl_renderer_pixeltest.cc
+++ b/cc/output/gl_renderer_pixeltest.cc
@@ -524,58 +524,6 @@ TEST_F(GLRendererPixelTest, AntiAliasing) {
       base::FilePath(FILE_PATH_LITERAL("anti_aliasing.png")),
       ExactPixelComparator(true)));
 }
-
-TEST_F(GLRendererPixelTest, AxisAligned) {
-  gfx::Rect rect(0, 0, 200, 200);
-
-  RenderPass::Id id(1, 1);
-  gfx::Transform transform_to_root;
-  scoped_ptr<RenderPass> pass =
-      CreateTestRenderPass(id, rect, transform_to_root);
-
-  gfx::Transform red_content_to_target_transform;
-  red_content_to_target_transform.Translate(50, 50);
-  red_content_to_target_transform.Scale(
-      0.5f + 1.0f / (rect.width() * 2.0f),
-      0.5f + 1.0f / (rect.height() * 2.0f));
-  scoped_ptr<SharedQuadState> red_shared_state =
-      CreateTestSharedQuadState(red_content_to_target_transform, rect);
-
-  scoped_ptr<SolidColorDrawQuad> red = SolidColorDrawQuad::Create();
-  red->SetNew(red_shared_state.get(), rect, SK_ColorRED);
-
-  pass->quad_list.push_back(red.PassAs<DrawQuad>());
-
-  gfx::Transform yellow_content_to_target_transform;
-  yellow_content_to_target_transform.Translate(25.5f, 25.5f);
-  yellow_content_to_target_transform.Scale(0.5f, 0.5f);
-  scoped_ptr<SharedQuadState> yellow_shared_state =
-      CreateTestSharedQuadState(yellow_content_to_target_transform, rect);
-
-  scoped_ptr<SolidColorDrawQuad> yellow = SolidColorDrawQuad::Create();
-  yellow->SetNew(yellow_shared_state.get(), rect, SK_ColorYELLOW);
-
-  pass->quad_list.push_back(yellow.PassAs<DrawQuad>());
-
-  gfx::Transform blue_content_to_target_transform;
-  scoped_ptr<SharedQuadState> blue_shared_state =
-      CreateTestSharedQuadState(blue_content_to_target_transform, rect);
-
-  scoped_ptr<SolidColorDrawQuad> blue = SolidColorDrawQuad::Create();
-  blue->SetNew(blue_shared_state.get(), rect, SK_ColorBLUE);
-
-  pass->quad_list.push_back(blue.PassAs<DrawQuad>());
-
-  RenderPassList pass_list;
-  pass_list.push_back(pass.Pass());
-
-  renderer_->DrawFrame(&pass_list);
-
-  EXPECT_TRUE(PixelsMatchReference(
-      base::FilePath(FILE_PATH_LITERAL("axis_aligned.png")),
-      ExactPixelComparator(true)));
-}
-
 #endif
 
 }  // namespace
diff --git a/cc/output/gl_renderer_unittest.cc b/cc/output/gl_renderer_unittest.cc
index bbd261a..ef56cc2 100644
--- a/cc/output/gl_renderer_unittest.cc
+++ b/cc/output/gl_renderer_unittest.cc
@@ -325,12 +325,6 @@ class GLRendererShaderTest : public testing::Test {
         renderer_->render_pass_color_matrix_program_aa_->program());
   }
 
-  void TestSolidColorProgramAA() {
-    EXPECT_PROGRAM_VALID(renderer_->solid_color_program_aa_);
-    EXPECT_TRUE(renderer_->program_shadow_ ==
-        renderer_->solid_color_program_aa_->program());
-  }
-
   scoped_ptr<OutputSurface> output_surface_;
   FakeRendererClient mock_client_;
   scoped_ptr<ResourceProvider> resource_provider_;
@@ -1277,34 +1271,6 @@ TEST_F(GLRendererShaderTest, DrawRenderPassQuadShaderPermutations) {
   TestRenderPassMaskColorMatrixProgramAA();
 }
 
-TEST_F(GLRendererShaderTest, DrawSolidColorShader) {
-  gfx::Rect viewport_rect(mock_client_.DeviceViewportSize());
-  ScopedPtrVector<RenderPass>* render_passes =
-      mock_client_.render_passes_in_draw_order();
-
-  RenderPass::Id root_pass_id(1, 0);
-  TestRenderPass* root_pass;
-
-  gfx::Transform pixel_aligned_transform_causing_aa;
-  pixel_aligned_transform_causing_aa.Translate(25.5f, 25.5f);
-  pixel_aligned_transform_causing_aa.Scale(0.5f, 0.5f);
-
-  render_passes->clear();
-
-  root_pass = AddRenderPass(
-      render_passes, root_pass_id, viewport_rect, gfx::Transform());
-  AddTransformedQuad(root_pass,
-                     viewport_rect,
-                     SK_ColorYELLOW,
-                     pixel_aligned_transform_causing_aa);
-
-  renderer_->DecideRenderPassAllocationsForFrame(
-      *mock_client_.render_passes_in_draw_order());
-  renderer_->DrawFrame(mock_client_.render_passes_in_draw_order());
-
-  TestSolidColorProgramAA();
-}
-
 class OutputSurfaceMockContext : public TestWebGraphicsContext3D {
  public:
   // Specifically override methods even if they are unused (used in conjunction
diff --git a/cc/test/data/axis_aligned.png b/cc/test/data/axis_aligned.png
deleted file mode 100644
index e69de29..0000000
--- a/cc/test/data/axis_aligned.png
+++ /dev/null
diff --git a/cc/test/render_pass_test_utils.cc b/cc/test/render_pass_test_utils.cc
index 719be7f..24cb778 100644
--- a/cc/test/render_pass_test_utils.cc
+++ b/cc/test/render_pass_test_utils.cc
@@ -57,22 +57,6 @@ SolidColorDrawQuad* AddClippedQuad(TestRenderPass* pass,
   return quad_ptr;
 }
 
-SolidColorDrawQuad* AddTransformedQuad(TestRenderPass* pass,
-                                       gfx::Rect rect,
-                                       SkColor color,
-                                       const gfx::Transform& transform) {
-  MockQuadCuller quad_sink(&pass->quad_list, &pass->shared_quad_state_list);
-  AppendQuadsData data(pass->id);
-  SharedQuadState* shared_state =
-      quad_sink.UseSharedQuadState(SharedQuadState::Create());
-  shared_state->SetAll(transform, rect.size(), rect, rect, false, 1);
-  scoped_ptr<SolidColorDrawQuad> quad = SolidColorDrawQuad::Create();
-  quad->SetNew(shared_state, rect, color);
-  SolidColorDrawQuad* quad_ptr = quad.get();
-  quad_sink.Append(quad.PassAs<DrawQuad>(), &data);
-  return quad_ptr;
-}
-
 void AddRenderPassQuad(TestRenderPass* to_pass,
                        TestRenderPass* contributing_pass) {
   MockQuadCuller quad_sink(&to_pass->quad_list,
diff --git a/cc/test/render_pass_test_utils.h b/cc/test/render_pass_test_utils.h
index 01a7ca0..fdc6366 100644
--- a/cc/test/render_pass_test_utils.h
+++ b/cc/test/render_pass_test_utils.h
@@ -38,12 +38,6 @@ SolidColorDrawQuad* AddClippedQuad(TestRenderPass* pass,
                                    gfx::Rect rect,
                                    SkColor color);
 
-// Adds a solid quad with a transform to a given render pass.
-SolidColorDrawQuad* AddTransformedQuad(TestRenderPass* pass,
-                                       gfx::Rect rect,
-                                       SkColor color,
-                                       const gfx::Transform& transform);
-
 // Adds a render pass quad to an existing render pass.
 void AddRenderPassQuad(TestRenderPass* to_pass,
                        TestRenderPass* contributing_pass);