Stop displaying layers with non-invertible transforms.

cc/layers/layer_impl_unittest.cc

 // Copyright 2011 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/layer_impl.h"
 
 #include "cc/output/filter_operation.h"
 #include "cc/output/filter_operations.h"
 #include "cc/test/fake_impl_proxy.h"
 #include "cc/test/fake_layer_tree_host_impl.h"
@@ skipping 368 matching lines @@
         } else {
           EXPECT_NE(SkColorGetA(safe_color), 255u)
               << "Flags: " << contents_opaque << ", " << layer_opaque << ", "
               << host_opaque << "\n";
         }
       }
     }
   }
 }
 
+TEST(LayerImplTest, TransformInvertibility) {
+  FakeImplProxy proxy;
+  TestSharedBitmapManager shared_bitmap_manager;
+  FakeLayerTreeHostImpl host_impl(&proxy, &shared_bitmap_manager);
+
+  scoped_ptr<LayerImpl> layer = LayerImpl::Create(host_impl.active_tree(), 1);
+  EXPECT_TRUE(layer->transform().IsInvertible());
+  EXPECT_TRUE(layer->transform_is_invertible());
+
+  gfx::Transform transform;
+  transform.Scale3d(
+      SkDoubleToMScalar(1.0), SkDoubleToMScalar(1.0), SkDoubleToMScalar(0.0));
+  layer->SetTransform(transform);
+  EXPECT_FALSE(layer->transform().IsInvertible());
+  EXPECT_FALSE(layer->transform_is_invertible());
+
+  transform.MakeIdentity();
+  transform.ApplyPerspectiveDepth(SkDoubleToMScalar(100.0));
+  transform.RotateAboutZAxis(75.0);
+  transform.RotateAboutXAxis(32.2);
+  transform.RotateAboutZAxis(-75.0);
+  transform.Translate3d(SkDoubleToMScalar(50.5),
+                        SkDoubleToMScalar(42.42),
+                        SkDoubleToMScalar(-100.25));
+
+  layer->SetTransform(transform);
+  EXPECT_TRUE(layer->transform().IsInvertible());
+  EXPECT_TRUE(layer->transform_is_invertible());
+}
+
 class LayerImplScrollTest : public testing::Test {
  public:
   LayerImplScrollTest()
       : host_impl_(&proxy_, &shared_bitmap_manager_), root_id_(7) {
     host_impl_.active_tree()->SetRootLayer(
         LayerImpl::Create(host_impl_.active_tree(), root_id_));
     host_impl_.active_tree()->root_layer()->AddChild(
         LayerImpl::Create(host_impl_.active_tree(), root_id_ + 1));
     layer()->SetScrollClipLayer(root_id_);
     // Set the max scroll offset by noting that the root layer has bounds (1,1),
@@ skipping 244 matching lines @@
   layer()->set_user_scrollable_vertical(false);
   layer()->SetScrollOffset(scroll_offset);
   gfx::Vector2dF unscrolled = layer()->ScrollBy(scroll_delta);
 
   EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 8.5f), unscrolled);
   EXPECT_VECTOR_EQ(gfx::Vector2dF(30.5f, 5), layer()->TotalScrollOffset());
 }
 
 }  // namespace
 }  // namespace cc