Add support for flattening in GeometryMapper.

third_party/WebKit/Source/platform/graphics/paint/GeometryMapperTest.cpp

 // Copyright 2016 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 "platform/graphics/paint/GeometryMapper.h"
 
 #include "platform/geometry/GeometryTestHelpers.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/graphics/BoxReflection.h"
 #include "platform/graphics/filters/SkiaImageFilterBuilder.h"
@@ skipping 258 matching lines @@
   bool hasRadius = false;
   CHECK_MAPPINGS(input, output, output, final, FloatClipRect(), localState,
                  rootPropertyTreeState(), hasRadius);
 
   // Check the cached matrix for the intermediate transform.
   EXPECT_EQ(
       rotateTransform,
       *getTransform(transform1.get(), rootPropertyTreeState().transform()));
 }
 
+TEST_F(GeometryMapperTest, NestedTransformsFlattening) {
+  TransformationMatrix rotateTransform;
+  rotateTransform.rotate3d(45, 0, 0);
+  RefPtr<TransformPaintPropertyNode> transform1 =
+      TransformPaintPropertyNode::create(rootPropertyTreeState().transform(),
+                                         rotateTransform, FloatPoint3D());
+
+  TransformationMatrix inverseRotateTransform;
+  inverseRotateTransform.rotate3d(-45, 0, 0);
+  RefPtr<TransformPaintPropertyNode> transform2 =
+      TransformPaintPropertyNode::create(transform1, inverseRotateTransform,
+                                         FloatPoint3D(),
+                                         true);  // Flattens
+
+  PropertyTreeState localState = rootPropertyTreeState();
+  localState.setTransform(transform2.get());
+
+  FloatRect input(0, 0, 100, 100);
+  rotateTransform.flattenTo2d();
+  TransformationMatrix final = rotateTransform * inverseRotateTransform;
+  FloatRect output = final.mapRect(input);
+  bool hasRadius = false;
+  CHECK_MAPPINGS(input, output, output, final, FloatClipRect(), localState,
+                 rootPropertyTreeState(), hasRadius);
+}
+
 TEST_F(GeometryMapperTest, NestedTransformsScaleAndTranslation) {
   TransformationMatrix scaleTransform;
   scaleTransform.scale(2);
   RefPtr<TransformPaintPropertyNode> transform1 =
       TransformPaintPropertyNode::create(rootPropertyTreeState().transform(),
                                          scaleTransform, FloatPoint3D());
 
   TransformationMatrix translateTransform;
   translateTransform.translate(100, 0);
   RefPtr<TransformPaintPropertyNode> transform2 =
@@ skipping 523 matching lines @@
   output = filters.mapRect(output);
   EXPECT_EQ(FloatRect(-50, -50, 210, 210), output);
   // 4. clipAboveEffect
   output.intersect(clipAboveEffect->clipRect().rect());
   EXPECT_EQ(FloatRect(-50, -50, 150, 150), output);
   // 5. transformAboveEffect
   output = transformAboveEffect->matrix().mapRect(output);
   EXPECT_EQ(FloatRect(-150, -150, 450, 450), output);
 
   bool hasRadius = false;
-  CHECK_MAPPINGS(
-      input, output, FloatRect(0, 0, 300, 300),
-      transformAboveEffect->matrix() * transformBelowEffect->matrix(),
-      FloatClipRect(FloatRect(30, 30, 270, 270)), localState,
-      rootPropertyTreeState(), hasRadius);
+  TransformationMatrix combinedTransform =
+      transformAboveEffect->matrix() * transformBelowEffect->matrix();
+  CHECK_MAPPINGS(input, output, FloatRect(0, 0, 300, 300), combinedTransform,
+                 FloatClipRect(FloatRect(30, 30, 270, 270)), localState,
+                 rootPropertyTreeState(), hasRadius);
 }
 
 TEST_F(GeometryMapperTest, ReflectionWithPaintOffset) {
   CompositorFilterOperations filters;
   filters.appendReferenceFilter(SkiaImageFilterBuilder::buildBoxReflectFilter(
       BoxReflection(BoxReflection::HorizontalReflection, 0), nullptr));
   RefPtr<EffectPaintPropertyNode> effect = EffectPaintPropertyNode::create(
       rootPropertyTreeState().effect(), rootPropertyTreeState().transform(),
       rootPropertyTreeState().clip(), ColorFilterNone, filters, 1.0,
       SkBlendMode::kSrcOver, CompositingReasonNone, CompositorElementId(),
       FloatPoint(100, 100));
 
   PropertyTreeState localState = rootPropertyTreeState();
   localState.setEffect(effect);
 
   FloatRect input(100, 100, 50, 50);
   // Reflection is at (50, 100, 50, 50).
   FloatRect output(50, 100, 100, 50);
 
   bool hasRadius = false;
   CHECK_MAPPINGS(input, output, input, TransformationMatrix(), FloatClipRect(),
                  localState, rootPropertyTreeState(), hasRadius);
 }
 
 }  // namespace blink