gfx/layers/AnimationHelper.h
author Hiroyuki Ikezoe <hikezoe@mozilla.com>
Tue, 31 Jul 2018 06:13:15 +0900
changeset 429252 2ffc8e9d5686766189b3d287f086fca8e0d2d8dd
parent 420862 b54db66223586b4e04f5cb926fccdacf8a176b91
child 429253 c8c2625a33baf37d1122814ee9a04dfcf40cf180
permissions -rw-r--r--
Bug 1479234 - Introduce a generic function to get an animation value on the compositor. r=boris,froydnj On the compositor we store animation values in a hash table and the hash is the compositor animation id which is a unique id for each property respectively. So we can get the corresponding animation value for the given property. In this patch there are lots of duplicated code, but they will be removed in the next patch. MozReview-Commit-ID: 7EboVcculcg

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_layers_AnimationHelper_h
#define mozilla_layers_AnimationHelper_h

#include "mozilla/dom/Nullable.h"
#include "mozilla/ComputedTimingFunction.h" // for ComputedTimingFunction
#include "mozilla/layers/LayersMessages.h" // for TransformData, etc
#include "mozilla/TimeStamp.h"          // for TimeStamp
#include "mozilla/TimingParams.h"
#include "X11UndefineNone.h"

namespace mozilla {
struct AnimationValue;
namespace layers {
class Animation;

typedef InfallibleTArray<layers::Animation> AnimationArray;

struct AnimData {
  InfallibleTArray<RefPtr<RawServoAnimationValue>> mStartValues;
  InfallibleTArray<RefPtr<RawServoAnimationValue>> mEndValues;
  InfallibleTArray<Maybe<mozilla::ComputedTimingFunction>> mFunctions;
  TimingParams mTiming;
  // These two variables correspond to the variables of the same name in
  // KeyframeEffectReadOnly and are used for the same purpose: to skip composing
  // animations whose progress has not changed.
  dom::Nullable<double> mProgressOnLastCompose;
  uint64_t mCurrentIterationOnLastCompose = 0;
  // These two variables are used for a similar optimization above but are
  // applied to the timing function in each keyframe.
  uint32_t mSegmentIndexOnLastCompose = 0;
  dom::Nullable<double> mPortionInSegmentOnLastCompose;
};

struct AnimationTransform {
  /*
   * This transform is calculated from sampleanimation in device pixel
   * and used by compositor.
   */
  gfx::Matrix4x4 mTransformInDevSpace;
  /*
   * This transform is calculated from frame and used by getOMTAStyle()
   * for OMTA testing.
   */
  gfx::Matrix4x4 mFrameTransform;
  TransformData mData;
};

struct AnimatedValue {
  enum {
    TRANSFORM,
    OPACITY,
    NONE
  } mType {NONE};

  union {
    AnimationTransform mTransform;
    float mOpacity;
  };

  AnimatedValue(gfx::Matrix4x4&& aTransformInDevSpace,
                gfx::Matrix4x4&& aFrameTransform,
                const TransformData& aData)
    : mType(AnimatedValue::TRANSFORM)
  {
    mTransform.mTransformInDevSpace = std::move(aTransformInDevSpace);
    mTransform.mFrameTransform = std::move(aFrameTransform);
    mTransform.mData = aData;
  }

  explicit AnimatedValue(const float& aValue)
    : mType(AnimatedValue::OPACITY)
    , mOpacity(aValue)
  {
  }

  ~AnimatedValue() {}

private:
  AnimatedValue() = delete;
};

// CompositorAnimationStorage stores the animations and animated values
// keyed by a CompositorAnimationsId. The "animations" are a representation of
// an entire animation over time, while the "animated values" are values sampled
// from the animations at a particular point in time.
//
// There is one CompositorAnimationStorage per CompositorBridgeParent (i.e.
// one per browser window), and the CompositorAnimationsId key is unique within
// a particular CompositorAnimationStorage instance.
//
// Each layer which has animations gets a CompositorAnimationsId key, and reuses
// that key during its lifetime. Likewise, in layers-free webrender, a display
// item that is animated (e.g. nsDisplayTransform) gets a CompositorAnimationsId
// key and reuses that key (it persists the key via the frame user-data
// mechanism).
class CompositorAnimationStorage final
{
  typedef nsClassHashtable<nsUint64HashKey, AnimatedValue> AnimatedValueTable;
  typedef nsClassHashtable<nsUint64HashKey, AnimationArray> AnimationsTable;

  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CompositorAnimationStorage)
public:

  /**
   * Set the animation transform based on the unique id and also
   * set up |aFrameTransform| and |aData| for OMTA testing
   */
  void SetAnimatedValue(uint64_t aId,
                        gfx::Matrix4x4&& aTransformInDevSpace,
                        gfx::Matrix4x4&& aFrameTransform,
                        const TransformData& aData);

  /**
   * Set the animation transform in device pixel based on the unique id
   */
  void SetAnimatedValue(uint64_t aId,
                        gfx::Matrix4x4&& aTransformInDevSpace);

  /**
   * Set the animation opacity based on the unique id
   */
  void SetAnimatedValue(uint64_t aId, const float& aOpacity);

  /**
   * Return the animated value if a given id can map to its animated value
   */
  AnimatedValue* GetAnimatedValue(const uint64_t& aId) const;

  /**
   * Like GetAnimatedValue(), but ensures the value is an opacity and returns
   * the float value if possible, or Nothing() otherwise.
   */
  Maybe<float> GetAnimationOpacity(const uint64_t& aId) const;

  /**
   * Like GetAnimatedValue(), but ensures the value is a transform and returns
   * the transform matrix if possible, or Nothing() otherwise. It also does
   * some post-processing on the transform matrix as well. See the comments
   * inside the function for details.
   */
  Maybe<gfx::Matrix4x4> GetAnimationTransform(const uint64_t& aId) const;

  OMTAValue GetOMTAValue(const uint64_t& aId) const;

  /**
   * Return the iterator of animated value table
   */
  AnimatedValueTable::Iterator ConstAnimatedValueTableIter() const
  {
    return mAnimatedValues.ConstIter();
  }

  uint32_t AnimatedValueCount() const
  {
    return mAnimatedValues.Count();
  }

  /**
   * Set the animations based on the unique id
   */
  void SetAnimations(uint64_t aId, const AnimationArray& aAnimations);

  /**
   * Return the animations if a given id can map to its animations
   */
  AnimationArray* GetAnimations(const uint64_t& aId) const;

  /**
   * Return the iterator of animations table
   */
  AnimationsTable::Iterator ConstAnimationsTableIter() const
  {
    return mAnimations.ConstIter();
  }

  uint32_t AnimationsCount() const
  {
    return mAnimations.Count();
  }

  /**
   * Clear AnimatedValues and Animations data
   */
  void Clear();
  void ClearById(const uint64_t& aId);

private:
  ~CompositorAnimationStorage() { };

private:
  AnimatedValueTable mAnimatedValues;
  AnimationsTable mAnimations;
};

/**
 * This utility class allows reusing code between the webrender and
 * non-webrender compositor-side implementations. It provides
 * utility functions for sampling animations at particular timestamps.
 */
class AnimationHelper
{
public:

  enum class SampleResult {
    None,
    Skipped,
    Sampled
  };

  /**
   * Sample animations based on a given time stamp for a element(layer) with
   * its animation data.
   * Generally |aPreviousFrameTimeStamp| is used for the sampling if it's
   * supplied to make the animation more in sync with other animations on the
   * main-thread.  But in the case where the animation just started at the time
   * when the animation was sent to the compositor, |aCurrentTime| is used for
   * the sampling instead to avoid flickering the animation.
   *
   * Returns SampleResult::None if none of the animations are producing a result
   * (e.g. they are in the delay phase with no backwards fill),
   * SampleResult::Skipped if the animation output did not change since the last
   * call of this function,
   * SampleResult::Sampled if the animation output was updated.
   */
  static SampleResult
  SampleAnimationForEachNode(TimeStamp aPreviousFrameTime,
                             TimeStamp aCurrentFrameTime,
                             AnimationArray& aAnimations,
                             InfallibleTArray<AnimData>& aAnimationData,
                             RefPtr<RawServoAnimationValue>& aAnimationValue,
                             const AnimatedValue* aPreviousValue);
  /**
   * Populates AnimData stuctures into |aAnimData| and |aBaseAnimationStyle|
   * based on |aAnimations|.
   */
  static void
  SetAnimations(AnimationArray& aAnimations,
                InfallibleTArray<AnimData>& aAnimData,
                RefPtr<RawServoAnimationValue>& aBaseAnimationStyle);

  /**
   * Get a unique id to represent the compositor animation between child
   * and parent side. This id will be used as a key to store animation
   * data in the CompositorAnimationStorage per compositor.
   * Each layer on the content side calls this when it gets new animation
   * data.
   */
  static uint64_t GetNextCompositorAnimationsId();

  /**
   * Sample animation based a given time stamp |aTime| and the animation
   * data inside CompositorAnimationStorage |aStorage|. The animated values
   * after sampling will be stored in CompositorAnimationStorage as well.
   *
   * Returns true if there is any animation.
   * Note that even if there are only in-delay phase animations (i.e. not
   * visually effective), this function returns true to ensure we composite
   * again on the next tick.
   */
  static bool
  SampleAnimations(CompositorAnimationStorage* aStorage,
                   TimeStamp aPreviousFrameTime,
                   TimeStamp aCurrentFrameTime);
};

} // namespace layers
} // namespace mozilla

#endif // mozilla_layers_AnimationHelper_h