Only allow change-of-basis between transform nodes on the same ancestor chain

cc/trees/property_tree_unittest.cc

 // Copyright 2014 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/trees/property_tree.h"
 
 #include "cc/test/geometry_test_utils.h"
 #include "cc/trees/draw_property_utils.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 63 matching lines @@
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
 
   transform.MakeIdentity();
   expected.MakeIdentity();
   expected.Translate(-5, -5);
   success = tree.ComputeTransform(-1, 1, &transform);
   EXPECT_TRUE(success);
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
 }
 
-TEST(PropertyTreeTest, ComputeTransformSibling) {
-  TransformTree tree;
-  TransformNode& root = *tree.Node(0);
-  root.data.local.Translate(2, 2);
-  root.data.target_id = 0;
-  tree.UpdateTransforms(0);
-
-  TransformNode child;
-  child.data.local.Translate(3, 3);
-  child.data.target_id = 0;
-
-  TransformNode sibling;
-  sibling.data.local.Translate(7, 7);
-  sibling.data.target_id = 0;
-
-  tree.Insert(child, 0);
-  tree.Insert(sibling, 0);
-
-  tree.UpdateTransforms(1);
-  tree.UpdateTransforms(2);
-
-  gfx::Transform expected;
-  gfx::Transform transform;
-
-  expected.Translate(4, 4);
-  bool success = tree.ComputeTransform(2, 1, &transform);
-  EXPECT_TRUE(success);
-  EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
-
-  transform.MakeIdentity();
-  expected.MakeIdentity();
-  expected.Translate(-4, -4);
-  success = tree.ComputeTransform(1, 2, &transform);
-  EXPECT_TRUE(success);
-  EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
-}
-
-TEST(PropertyTreeTest, ComputeTransformSiblingSingularAncestor) {
-  // In this test, we have the following tree:
-  // root
-  //   + singular
-  //     + child
-  //     + sibling
-  // Now singular has a singular transform, so we cannot use screen space
-  // transforms to compute change of basis transforms between |child| and
-  // |sibling|.
-  TransformTree tree;
-  TransformNode& root = *tree.Node(0);
-  root.data.local.Translate(2, 2);
-  root.data.target_id = 0;
-  tree.UpdateTransforms(0);
-
-  TransformNode singular;
-  singular.data.local.matrix().set(2, 2, 0.0);
-  singular.data.target_id = 0;
-
-  TransformNode child;
-  child.data.local.Translate(3, 3);
-  child.data.target_id = 0;
-
-  TransformNode sibling;
-  sibling.data.local.Translate(7, 7);
-  sibling.data.target_id = 0;
-
-  tree.Insert(singular, 0);
-  tree.Insert(child, 1);
-  tree.Insert(sibling, 1);
-
-  tree.UpdateTransforms(1);
-  tree.UpdateTransforms(2);
-  tree.UpdateTransforms(3);
-
-  gfx::Transform expected;
-  gfx::Transform transform;
-
-  expected.Translate(4, 4);
-  bool success = tree.ComputeTransform(3, 2, &transform);
-  EXPECT_TRUE(success);
-  EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
-
-  transform.MakeIdentity();
-  expected.MakeIdentity();
-  expected.Translate(-4, -4);
-  success = tree.ComputeTransform(2, 3, &transform);
-  EXPECT_TRUE(success);
-  EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
-}
-
 TEST(PropertyTreeTest, TransformsWithFlattening) {
   TransformTree tree;
 
   int grand_parent = tree.Insert(TransformNode(), 0);
   tree.Node(grand_parent)->data.content_target_id = grand_parent;
   tree.Node(grand_parent)->data.target_id = grand_parent;
 
   gfx::Transform rotation_about_x;
   rotation_about_x.RotateAboutXAxis(15);
 
@@ skipping 112 matching lines @@
   EXPECT_TRUE(success);
   EXPECT_TRANSFORMATION_MATRIX_EQ(expected, transform);
 
   // To compute this would require inverting the 0 matrix, so we cannot
   // succeed.
   success = tree.ComputeTransform(0, 1, &inverse);
   EXPECT_FALSE(success);
 }
 
 }  // namespace cc