Add support for inverse transform animations.

This allows creation of a transform and its inverse that would be used
to counter-animate some child layer.

BUG=270857

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=220124

R=vollick@chromium.org, wittman@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=220479

Review URL: https://chromiumcodereview.appspot.com/22861008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@221309 0039d316-1c4b-4281-b951-d872f2087c98

ui/compositor/compositor.gyp

@@ -123,6 +123,7 @@
         'test/test_layer_animation_observer.h',
         'test/test_utils.cc',
         'test/test_utils.h',
+        'transform_animation_curve_adapter_unittest.cc',
       ],
       'conditions': [
         # osmesa GL implementation is used on linux.

ui/compositor/layer_animation_element.cc

@@ -394,6 +394,10 @@ class ThreadedLayerAnimationElement : public LayerAnimationElement {
   }
 
  protected:
+  explicit ThreadedLayerAnimationElement(const LayerAnimationElement& element)
+    : LayerAnimationElement(element) {
+  }
+
   virtual bool OnProgress(double t,
                           LayerAnimationDelegate* delegate) OVERRIDE {
     if (t < 1.0)
@@ -563,6 +567,117 @@ class ThreadedTransformTransition : public ThreadedLayerAnimationElement {
   DISALLOW_COPY_AND_ASSIGN(ThreadedTransformTransition);
 };
 
+// InverseTransformTransision --------------------------------------------------
+
+class InverseTransformTransition : public ThreadedLayerAnimationElement {
+ public:
+  InverseTransformTransition(const gfx::Transform& base_transform,
+                             const LayerAnimationElement* uninverted_transition)
+      : ThreadedLayerAnimationElement(*uninverted_transition),
+        base_transform_(base_transform),
+        uninverted_transition_(CheckAndCast(uninverted_transition)) {
+  }
+  virtual ~InverseTransformTransition() {}
+
+ protected:
+  virtual void OnStart(LayerAnimationDelegate* delegate) OVERRIDE {
+    gfx::Transform start(delegate->GetTransformForAnimation());
+    effective_start_ = base_transform_ * start;
+
+    TargetValue target;
+    uninverted_transition_->GetTargetValue(&target);
+    base_target_ = target.transform;
+
+    set_tween_type(uninverted_transition_->tween_type());
+
+    float device_scale_factor = delegate->GetDeviceScaleFactor();
+    const gfx::Transform cc_base_start = Layer::ConvertTransformToCCTransform(
+        base_transform_,
+        device_scale_factor);
+    const gfx::Transform cc_base_target = Layer::ConvertTransformToCCTransform(
+        base_target_,
+        device_scale_factor);
+    TransformAnimationCurveAdapter base_curve(tween_type(),
+                                              cc_base_start,
+                                              cc_base_target,
+                                              duration());
+
+    const gfx::Transform cc_start = Layer::ConvertTransformToCCTransform(
+        start, device_scale_factor);
+    animation_curve_.reset(new InverseTransformCurveAdapter(
+        base_curve, cc_start, duration()));
+    computed_target_transform_ = ComputeWithBaseTransform(effective_start_,
+                                                          base_target_);
+  }
+
+  virtual void OnAbort(LayerAnimationDelegate* delegate) OVERRIDE {
+    if (delegate && Started()) {
+      ThreadedLayerAnimationElement::OnAbort(delegate);
+      delegate->SetTransformFromAnimation(ComputeCurrentTransform());
+    }
+  }
+
+  virtual void OnEnd(LayerAnimationDelegate* delegate) OVERRIDE {
+    delegate->SetTransformFromAnimation(computed_target_transform_);
+  }
+
+  virtual scoped_ptr<cc::Animation> CreateCCAnimation() OVERRIDE {
+    scoped_ptr<cc::Animation> animation(
+        cc::Animation::Create(animation_curve_->Clone(),
+                              animation_id(),
+                              animation_group_id(),
+                              cc::Animation::Transform));
+    return animation.Pass();
+  }
+
+  virtual void OnGetTarget(TargetValue* target) const OVERRIDE {
+    target->transform = computed_target_transform_;
+  }
+
+ private:
+  gfx::Transform ComputeCurrentTransform() const {
+    gfx::Transform base_current = Tween::ValueBetween(
+        Tween::CalculateValue(tween_type(), last_progressed_fraction()),
+        base_transform_,
+        base_target_);
+    return ComputeWithBaseTransform(effective_start_, base_current);
+  }
+
+  gfx::Transform ComputeWithBaseTransform(gfx::Transform start,
+                                          gfx::Transform target) const {
+    gfx::Transform to_return(gfx::Transform::kSkipInitialization);
+    DCHECK(target.GetInverse(&to_return));
+
+    to_return.PreconcatTransform(start);
+    return to_return;
+  }
+
+  static AnimatableProperties GetProperties() {
+    AnimatableProperties properties;
+    properties.insert(LayerAnimationElement::TRANSFORM);
+    return properties;
+  }
+
+  static const ThreadedTransformTransition* CheckAndCast(
+      const LayerAnimationElement* element) {
+    const AnimatableProperties& properties = element->properties();
+    DCHECK(properties.find(TRANSFORM) != properties.end());
+    return static_cast<const ThreadedTransformTransition*>(element);
+  }
+
+  gfx::Transform effective_start_;
+  gfx::Transform computed_target_transform_;
+
+  const gfx::Transform base_transform_;
+  gfx::Transform base_target_;
+
+  scoped_ptr<cc::AnimationCurve> animation_curve_;
+
+  const ThreadedTransformTransition* const uninverted_transition_;
+
+  DISALLOW_COPY_AND_ASSIGN(InverseTransformTransition);
+};
+
 }  // namespace
 
 // LayerAnimationElement::TargetValue ------------------------------------------
@@ -601,6 +716,17 @@ LayerAnimationElement::LayerAnimationElement(
       last_progressed_fraction_(0.0) {
 }
 
+LayerAnimationElement::LayerAnimationElement(
+    const LayerAnimationElement &element)
+    : first_frame_(element.first_frame_),
+      properties_(element.properties_),
+      duration_(element.duration_),
+      tween_type_(element.tween_type_),
+      animation_id_(cc::AnimationIdProvider::NextAnimationId()),
+      animation_group_id_(element.animation_group_id_),
+      last_progressed_fraction_(element.last_progressed_fraction_) {
+}
+
 LayerAnimationElement::~LayerAnimationElement() {
 }
 
@@ -728,6 +854,13 @@ LayerAnimationElement* LayerAnimationElement::CreateTransformElement(
   return new ThreadedTransformTransition(transform, duration);
 }
 
+// static
+LayerAnimationElement* LayerAnimationElement::CreateInverseTransformElement(
+    const gfx::Transform& base_transform,
+    const LayerAnimationElement* uninverted_transition) {
+  return new InverseTransformTransition(base_transform, uninverted_transition);
+}
+
 // static
 LayerAnimationElement*
 LayerAnimationElement::CreateInterpolatedTransformElement(

ui/compositor/layer_animation_element.h

@@ -57,6 +57,7 @@ class COMPOSITOR_EXPORT LayerAnimationElement {
 
   LayerAnimationElement(const AnimatableProperties& properties,
                         base::TimeDelta duration);
+
   virtual ~LayerAnimationElement();
 
   // Creates an element that transitions to the given transform. The caller owns
@@ -65,6 +66,14 @@ class COMPOSITOR_EXPORT LayerAnimationElement {
       const gfx::Transform& transform,
       base::TimeDelta duration);
 
+  // Creates an element that counters a transition to the given transform.
+  // This element maintains the invariant uninverted_transition->at(t) *
+  // this->at(t) == base_transform * this->at(t_start) for any t. The caller
+  // owns the return value.
+  static LayerAnimationElement* CreateInverseTransformElement(
+      const gfx::Transform& base_transform,
+      const LayerAnimationElement* uninverted_transition);
+
   // Creates an element that transitions to another in a way determined by an
   // interpolated transform. The element accepts ownership of the interpolated
   // transform. NB: at every step, the interpolated transform clobbers the
@@ -178,6 +187,8 @@ class COMPOSITOR_EXPORT LayerAnimationElement {
   int animation_group_id() const { return animation_group_id_; }
   void set_animation_group_id(int id) { animation_group_id_ = id; }
 
+  base::TimeDelta duration() const { return duration_; }
+
   // The fraction of the animation that has been completed after the last
   // call made to {Progress, ProgressToEnd}.
   double last_progressed_fraction() const { return last_progressed_fraction_; }
@@ -190,11 +201,11 @@ class COMPOSITOR_EXPORT LayerAnimationElement {
   virtual void OnGetTarget(TargetValue* target) const = 0;
   virtual void OnAbort(LayerAnimationDelegate* delegate) = 0;
 
-  base::TimeDelta duration() const { return duration_; }
-
   // Actually start the animation, dispatching to another thread if needed.
   virtual void RequestEffectiveStart(LayerAnimationDelegate* delegate);
 
+  LayerAnimationElement(const LayerAnimationElement& element);
+
  private:
   // For debugging purposes, we sometimes alter the duration we actually use.
   // For example, during tests we often set duration = 0, and it is sometimes
@@ -215,7 +226,7 @@ class COMPOSITOR_EXPORT LayerAnimationElement {
 
   double last_progressed_fraction_;
 
-  DISALLOW_COPY_AND_ASSIGN(LayerAnimationElement);
+  DISALLOW_ASSIGN(LayerAnimationElement);
 };
 
 }  // namespace ui

ui/compositor/layer_animation_element_unittest.cc

@@ -10,6 +10,7 @@
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/compositor/layer_animation_delegate.h"
+#include "ui/compositor/scoped_animation_duration_scale_mode.h"
 #include "ui/compositor/test/test_layer_animation_delegate.h"
 #include "ui/compositor/test/test_utils.h"
 #include "ui/gfx/rect.h"
@@ -23,7 +24,7 @@ namespace {
 // that the element can be reused after it completes.
 TEST(LayerAnimationElementTest, TransformElement) {
   TestLayerAnimationDelegate delegate;
-  gfx::Transform start_transform, target_transform, middle_transform;
+  gfx::Transform start_transform, target_transform;
   start_transform.Rotate(-30.0);
   target_transform.Rotate(30.0);
   base::TimeTicks start_time;
@@ -65,6 +66,36 @@ TEST(LayerAnimationElementTest, TransformElement) {
   CheckApproximatelyEqual(target_transform, target_value.transform);
 }
 
+// Ensures that duration is copied correctly.
+TEST(LayerAnimationElementTest, InverseElementDurationNoScale) {
+  gfx::Transform transform;
+  base::TimeDelta delta;
+
+  scoped_ptr<LayerAnimationElement> base_element(
+      LayerAnimationElement::CreateTransformElement(transform, delta));
+
+  scoped_ptr<LayerAnimationElement> inverse_element(
+      LayerAnimationElement::CreateInverseTransformElement(transform,
+                                                           base_element.get()));
+  EXPECT_EQ(base_element->duration(), inverse_element->duration());
+}
+
+// Ensures that duration is copied correctly and not double scaled.
+TEST(LayerAnimationElementTest, InverseElementDurationScaled) {
+  gfx::Transform transform;
+  base::TimeDelta delta;
+
+  ScopedAnimationDurationScaleMode faster_duration(
+      ScopedAnimationDurationScaleMode::FAST_DURATION);
+  scoped_ptr<LayerAnimationElement> base_element(
+      LayerAnimationElement::CreateTransformElement(transform, delta));
+
+  scoped_ptr<LayerAnimationElement> inverse_element(
+      LayerAnimationElement::CreateInverseTransformElement(transform,
+                                                           base_element.get()));
+  EXPECT_EQ(base_element->duration(), inverse_element->duration());
+}
+
 // Check that the bounds element progresses the delegate as expected and
 // that the element can be reused after it completes.
 TEST(LayerAnimationElementTest, BoundsElement) {

ui/compositor/test/test_utils.cc

@@ -10,13 +10,23 @@
 
 namespace ui {
 
+//TODO(avallee): Make this into a predicate and add some matrix pretty printing.
 void CheckApproximatelyEqual(const gfx::Transform& lhs,
                              const gfx::Transform& rhs) {
+  unsigned int errors = 0;
   for (int i = 0; i < 4; ++i) {
     for (int j = 0; j < 4; ++j) {
-      EXPECT_FLOAT_EQ(lhs.matrix().get(i, j), rhs.matrix().get(i, j));
+      EXPECT_FLOAT_EQ(lhs.matrix().get(i, j), rhs.matrix().get(i, j))
+        << "(i, j) = (" << i << ", " << j << "), error count: " << ++errors;
     }
   }
+
+  if (errors) {
+    ADD_FAILURE() << "Expected matrix:\n"
+                  << lhs.ToString() << "\n"
+                  << "Actual matrix:\n"
+                  << rhs.ToString();
+  }
 }
 
 void CheckApproximatelyEqual(const gfx::Rect& lhs, const gfx::Rect& rhs) {

ui/compositor/transform_animation_curve_adapter.cc

@@ -60,4 +60,53 @@ bool TransformAnimationCurveAdapter::AnimatedBoundsForBox(
   return false;
 }
 
+InverseTransformCurveAdapter::InverseTransformCurveAdapter(
+    TransformAnimationCurveAdapter base_curve,
+    gfx::Transform initial_value,
+    base::TimeDelta duration)
+    : base_curve_(base_curve),
+      initial_value_(initial_value),
+      duration_(duration) {
+  effective_initial_value_ = base_curve_.GetValue(0.0) * initial_value_;
+}
+
+InverseTransformCurveAdapter::~InverseTransformCurveAdapter() {
+}
+
+double InverseTransformCurveAdapter::Duration() const {
+  return duration_.InSeconds();
+}
+
+scoped_ptr<cc::AnimationCurve> InverseTransformCurveAdapter::Clone() const {
+  scoped_ptr<InverseTransformCurveAdapter> to_return(
+      new InverseTransformCurveAdapter(base_curve_,
+                                       initial_value_,
+                                       duration_));
+  return to_return.PassAs<cc::AnimationCurve>();
+}
+
+gfx::Transform InverseTransformCurveAdapter::GetValue(
+    double t) const {
+  if (t <= 0.0)
+    return initial_value_;
+
+  gfx::Transform base_transform = base_curve_.GetValue(t);
+  // Invert base
+  gfx::Transform to_return(gfx::Transform::kSkipInitialization);
+  bool is_invertible = base_transform.GetInverse(&to_return);
+  DCHECK(is_invertible);
+
+  to_return.PreconcatTransform(effective_initial_value_);
+  return to_return;
+}
+
+bool InverseTransformCurveAdapter::AnimatedBoundsForBox(
+    const gfx::BoxF& box,
+    gfx::BoxF* bounds) const {
+  // TODO(ajuma): Once cc::TransformOperation::BlendedBoundsForBox supports
+  // computing bounds for TransformOperationMatrix, use that to compute
+  // the bounds we need here.
+  return false;
+}
+
 }  // namespace ui

ui/compositor/transform_animation_curve_adapter.h

@@ -8,12 +8,14 @@
 #include "base/time/time.h"
 #include "cc/animation/animation_curve.h"
 #include "ui/base/animation/tween.h"
+#include "ui/compositor/compositor_export.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/transform_util.h"
 
 namespace ui {
 
-class TransformAnimationCurveAdapter :public cc::TransformAnimationCurve {
+class COMPOSITOR_EXPORT TransformAnimationCurveAdapter
+    : public cc::TransformAnimationCurve {
  public:
   TransformAnimationCurveAdapter(Tween::Type tween_type,
                                  gfx::Transform intial_value,
@@ -36,6 +38,32 @@ class TransformAnimationCurveAdapter :public cc::TransformAnimationCurve {
   gfx::DecomposedTransform decomposed_initial_value_;
   gfx::DecomposedTransform decomposed_target_value_;
   base::TimeDelta duration_;
+
+  DISALLOW_ASSIGN(TransformAnimationCurveAdapter);
+};
+
+class COMPOSITOR_EXPORT InverseTransformCurveAdapter
+    : public cc::TransformAnimationCurve {
+ public:
+  InverseTransformCurveAdapter(TransformAnimationCurveAdapter base_curve,
+                               gfx::Transform initial_value,
+                               base::TimeDelta duration);
+
+  virtual ~InverseTransformCurveAdapter();
+
+  virtual double Duration() const OVERRIDE;
+  virtual scoped_ptr<AnimationCurve> Clone() const OVERRIDE;
+  virtual gfx::Transform GetValue(double t) const OVERRIDE;
+  virtual bool AnimatedBoundsForBox(const gfx::BoxF& box,
+                                    gfx::BoxF* bounds) const OVERRIDE;
+
+ private:
+  TransformAnimationCurveAdapter base_curve_;
+  gfx::Transform initial_value_;
+  gfx::Transform effective_initial_value_;
+  base::TimeDelta duration_;
+
+  DISALLOW_ASSIGN(InverseTransformCurveAdapter);
 };
 
 }  // namespace ui

ui/compositor/transform_animation_curve_adapter_unittest.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.
+
+#include "ui/compositor/transform_animation_curve_adapter.h"
+
+#include <sstream>
+
+#include "base/time/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/compositor/test/test_utils.h"
+
+namespace ui {
+
+namespace {
+
+// Check that the inverse transform curve gives the gives a transform that when
+// applied on top of the parent transform gives the original transform
+TEST(InverseTransformCurveAdapterTest, InversesTransform) {
+  gfx::Transform parent_start, parent_target;
+  parent_start.Scale(0.5, 3.0);
+  parent_start.Translate(-20.0, 30.0);
+  parent_target.Translate(0, 100);
+
+  gfx::Transform child_transform;
+  child_transform.Rotate(-30.0);
+
+  base::TimeDelta duration = base::TimeDelta::FromSeconds(1);
+
+  const gfx::Transform effective_child_transform =
+      parent_start * child_transform;
+
+  TransformAnimationCurveAdapter parent_curve(Tween::LINEAR,
+                                              parent_start,
+                                              parent_target,
+                                              duration);
+
+  InverseTransformCurveAdapter child_curve(parent_curve,
+                                           child_transform,
+                                           duration);
+  static const int kSteps = 1000;
+  double step = 1.0 / kSteps;
+  for (int i = 0; i <= kSteps ; ++i) {
+    std::ostringstream message;
+    message << "Step " << i << " of " << kSteps;
+    SCOPED_TRACE(message.str());
+    gfx::Transform progress_parent_transform =
+            parent_curve.GetValue(i*step);
+    gfx::Transform progress_child_transform =
+            child_curve.GetValue(i*step);
+    CheckApproximatelyEqual(effective_child_transform,
+                            progress_parent_transform *
+                            progress_child_transform);
+  }
+}
+
+} // namespace
+
+} // namespace ui