Transform animations should not collapse by default when interpolating

cc/animation/transform_operations.cc

 // 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.
 
 // Needed on Windows to get |M_PI| from <cmath>
 #ifdef _WIN32
 #define _USE_MATH_DEFINES
 #endif
 
 #include "cc/animation/transform_operations.h"
@@ skipping 19 matching lines @@
   decomposed_transform_dirty_ = other.decomposed_transform_dirty_;
   if (!decomposed_transform_dirty_) {
     decomposed_transform_.reset(
         new gfx::DecomposedTransform(*other.decomposed_transform_.get()));
   }
 }
 
 TransformOperations::~TransformOperations() {
 }
 
+TransformOperations& TransformOperations::operator=(
+    const TransformOperations& other) {
+  operations_ = other.operations_;
+  decomposed_transform_dirty_ = other.decomposed_transform_dirty_;
+  if (!decomposed_transform_dirty_) {
+    decomposed_transform_.reset(
+        new gfx::DecomposedTransform(*other.decomposed_transform_.get()));
+  }
+  return *this;
+}
+
 gfx::Transform TransformOperations::Apply() const {
   gfx::Transform to_return;
   for (size_t i = 0; i < operations_.size(); ++i)
     to_return.PreconcatTransform(operations_[i].matrix);
   return to_return;
 }
 
-gfx::Transform TransformOperations::Blend(const TransformOperations& from,
-                                          SkMScalar progress) const {
-  gfx::Transform to_return;
+TransformOperations TransformOperations::Blend(const TransformOperations& from,
+                                               SkMScalar progress) const {
+  TransformOperations to_return;
   BlendInternal(from, progress, &to_return);
   return to_return;
 }
 
 bool TransformOperations::BlendedBoundsForBox(const gfx::BoxF& box,
                                               const TransformOperations& from,
                                               SkMScalar min_progress,
                                               SkMScalar max_progress,
                                               gfx::BoxF* bounds) const {
   *bounds = box;
@@ skipping 125 matching lines @@
   for (size_t i = 0; i < operations_.size(); ++i) {
     if (operations_[i].type != other.operations_[i].type)
       return false;
   }
 
   return true;
 }
 
 bool TransformOperations::CanBlendWith(
     const TransformOperations& other) const {
-  gfx::Transform dummy;
+  TransformOperations dummy;
   return BlendInternal(other, 0.5, &dummy);
 }
 
 void TransformOperations::AppendTranslate(SkMScalar x,
                                           SkMScalar y,
                                           SkMScalar z) {
   TransformOperation to_add;
   to_add.matrix.Translate3d(x, y, z);
   to_add.type = TransformOperation::TRANSFORM_OPERATION_TRANSLATE;
   to_add.translate.x = x;
   to_add.translate.y = y;
   to_add.translate.z = z;
   operations_.push_back(to_add);
   decomposed_transform_dirty_ = true;
 }
 
 void TransformOperations::AppendRotate(SkMScalar x,
                                        SkMScalar y,
                                        SkMScalar z,
                                        SkMScalar degrees) {
   TransformOperation to_add;
-  to_add.matrix.RotateAbout(gfx::Vector3dF(x, y, z), degrees);
   to_add.type = TransformOperation::TRANSFORM_OPERATION_ROTATE;
   to_add.rotate.axis.x = x;
   to_add.rotate.axis.y = y;
   to_add.rotate.axis.z = z;
   to_add.rotate.angle = degrees;
+  to_add.Bake();
   operations_.push_back(to_add);
   decomposed_transform_dirty_ = true;
 }
 
 void TransformOperations::AppendScale(SkMScalar x, SkMScalar y, SkMScalar z) {
   TransformOperation to_add;
-  to_add.matrix.Scale3d(x, y, z);
   to_add.type = TransformOperation::TRANSFORM_OPERATION_SCALE;
   to_add.scale.x = x;
   to_add.scale.y = y;
   to_add.scale.z = z;
+  to_add.Bake();
   operations_.push_back(to_add);
   decomposed_transform_dirty_ = true;
 }
 
 void TransformOperations::AppendSkew(SkMScalar x, SkMScalar y) {
   TransformOperation to_add;
-  to_add.matrix.Skew(x, y);
   to_add.type = TransformOperation::TRANSFORM_OPERATION_SKEW;
   to_add.skew.x = x;
   to_add.skew.y = y;
+  to_add.Bake();
   operations_.push_back(to_add);
   decomposed_transform_dirty_ = true;
 }
 
 void TransformOperations::AppendPerspective(SkMScalar depth) {
   TransformOperation to_add;
-  to_add.matrix.ApplyPerspectiveDepth(depth);
   to_add.type = TransformOperation::TRANSFORM_OPERATION_PERSPECTIVE;
   to_add.perspective_depth = depth;
+  to_add.Bake();
   operations_.push_back(to_add);
   decomposed_transform_dirty_ = true;
 }
 
 void TransformOperations::AppendMatrix(const gfx::Transform& matrix) {
   TransformOperation to_add;
   to_add.matrix = matrix;
   to_add.type = TransformOperation::TRANSFORM_OPERATION_MATRIX;
   operations_.push_back(to_add);
   decomposed_transform_dirty_ = true;
 }
 
 void TransformOperations::AppendIdentity() {
   operations_.push_back(TransformOperation());
 }
 
 bool TransformOperations::IsIdentity() const {
   for (size_t i = 0; i < operations_.size(); ++i) {
     if (!operations_[i].IsIdentity())
       return false;
   }
   return true;
 }
 
+void TransformOperations::Append(const TransformOperation& operation) {
+  operations_.push_back(operation);
+}
+
 bool TransformOperations::BlendInternal(const TransformOperations& from,
                                         SkMScalar progress,
-                                        gfx::Transform* result) const {
+                                        TransformOperations* result) const {
   bool from_identity = from.IsIdentity();
   bool to_identity = IsIdentity();
   if (from_identity && to_identity)
     return true;
 
   if (MatchesTypes(from)) {
     size_t num_operations =
         std::max(from_identity ? 0 : from.operations_.size(),
                  to_identity ? 0 : operations_.size());
     for (size_t i = 0; i < num_operations; ++i) {
-      gfx::Transform blended;
+      TransformOperation blended;
       if (!TransformOperation::BlendTransformOperations(
-          from_identity ? 0 : &from.operations_[i],
-          to_identity ? 0 : &operations_[i],
-          progress,
-          &blended))
-          return false;
-      result->PreconcatTransform(blended);
+              from_identity ? 0 : &from.operations_[i],
+              to_identity ? 0 : &operations_[i], progress, &blended)) {
+        return false;
+      }
+      result->Append(blended);
     }
     return true;
   }
 
   if (!ComputeDecomposedTransform() || !from.ComputeDecomposedTransform())
     return false;
 
   gfx::DecomposedTransform to_return;
   to_return = gfx::BlendDecomposedTransforms(*decomposed_transform_.get(),
                                              *from.decomposed_transform_.get(),
                                              progress);
 
-  *result = ComposeTransform(to_return);
+  result->AppendMatrix(ComposeTransform(to_return));
   return true;
 }
 
 bool TransformOperations::ComputeDecomposedTransform() const {
   if (decomposed_transform_dirty_) {
     if (!decomposed_transform_)
       decomposed_transform_.reset(new gfx::DecomposedTransform());
     gfx::Transform transform = Apply();
     if (!gfx::DecomposeTransform(decomposed_transform_.get(), transform))
       return false;
     decomposed_transform_dirty_ = false;
   }
   return true;
 }
 
 }  // namespace cc