Bug 1458457 - Move the logic that we use whether the previous time stamp or the last compose time stamp into SampleAnimationForEachNode. r=birtles

So that we can do an additional check depending on each animation in a subsequent
patch in this patch series.

MozReview-Commit-ID: C1ZJMdwraVk

--HG--
extra : rebase_source : baa71d25e45fbc1db20312788251bcced692b6cf

gfx/layers/AnimationHelper.cpp

@@ -148,7 +148,8 @@ CompositorAnimationStorage::SetAnimations(uint64_t aId, const AnimationArray& aV
 
 AnimationHelper::SampleResult
 AnimationHelper::SampleAnimationForEachNode(
-  TimeStamp aTime,
+  TimeStamp aPreviousFrameTime,
+  TimeStamp aCurrentFrameTime,
   AnimationArray& aAnimations,
   InfallibleTArray<AnimData>& aAnimationData,
   RefPtr<RawServoAnimationValue>& aAnimationValue)
@@ -175,13 +176,23 @@ AnimationHelper::SampleAnimationForEachNode(
                animation.isNotPlaying(),
                "If we are playing, we should have an origin time and a start"
                " time");
+
+    // Use a previous vsync time to make main thread animations and compositor
+    // more in sync with each other.
+    // On the initial frame we use the current frame time here so the timestamp
+    // on the second frame are the same as the initial frame, but it does not
+    // matter.
+    const TimeStamp& timeStamp = !aPreviousFrameTime.IsNull()
+      ? aPreviousFrameTime
+      : aCurrentFrameTime;
+
     // If the animation is not currently playing, e.g. paused or
     // finished, then use the hold time to stay at the same position.
     TimeDuration elapsedDuration =
       animation.isNotPlaying() ||
       animation.startTime().type() != MaybeTimeDuration::TTimeDuration
       ? animation.holdTime()
-      : (aTime - animation.originTime() -
+      : (timeStamp - animation.originTime() -
          animation.startTime().get_TimeDuration())
         .MultDouble(animation.playbackRate());
 
@@ -571,7 +582,8 @@ AnimationHelper::GetNextCompositorAnimationsId()
 
 void
 AnimationHelper::SampleAnimations(CompositorAnimationStorage* aStorage,
-                                  TimeStamp aTime)
+                                  TimeStamp aPreviousFrameTime,
+                                  TimeStamp aCurrentFrameTime)
 {
   MOZ_ASSERT(aStorage);
 
@@ -594,7 +606,8 @@ AnimationHelper::SampleAnimations(CompositorAnimationStorage* aStorage,
                                    animationData,
                                    animationValue);
     AnimationHelper::SampleResult sampleResult =
-      AnimationHelper::SampleAnimationForEachNode(aTime,
+      AnimationHelper::SampleAnimationForEachNode(aPreviousFrameTime,
+                                                  aCurrentFrameTime,
                                                   *animations,
                                                   animationData,
                                                   animationValue);

gfx/layers/AnimationHelper.h

@@ -214,6 +214,9 @@ public:
   /**
    * 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.
    *
    * Returns SampleResult::None if none of the animations are producing a result
    * (e.g. they are in the delay phase with no backwards fill),
@@ -222,7 +225,8 @@ public:
    * SampleResult::Sampled if the animation output was updated.
    */
   static SampleResult
-  SampleAnimationForEachNode(TimeStamp aTime,
+  SampleAnimationForEachNode(TimeStamp aPreviousFrameTime,
+                             TimeStamp aCurrentFrameTime,
                              AnimationArray& aAnimations,
                              InfallibleTArray<AnimData>& aAnimationData,
                              RefPtr<RawServoAnimationValue>& aAnimationValue);
@@ -251,7 +255,8 @@ public:
    */
   static void
   SampleAnimations(CompositorAnimationStorage* aStorage,
-                   TimeStamp aTime);
+                   TimeStamp aPreviousFrameTime,
+                   TimeStamp aCurrentFrameTime);
 };
 
 } // namespace layers

gfx/layers/composite/AsyncCompositionManager.cpp

@@ -673,7 +673,8 @@ ApplyAnimatedValue(Layer* aLayer,
 static bool
 SampleAnimations(Layer* aLayer,
                  CompositorAnimationStorage* aStorage,
-                 TimeStamp aTime)
+                 TimeStamp aPreviousFrameTime,
+                 TimeStamp aCurrentFrameTime)
 {
   bool isAnimating = false;
 
@@ -689,7 +690,8 @@ SampleAnimations(Layer* aLayer,
         RefPtr<RawServoAnimationValue> animationValue =
           layer->GetBaseAnimationStyle();
         AnimationHelper::SampleResult sampleResult =
-          AnimationHelper::SampleAnimationForEachNode(aTime,
+          AnimationHelper::SampleAnimationForEachNode(aPreviousFrameTime,
+                                                      aCurrentFrameTime,
                                                       animations,
                                                       layer->GetAnimationData(),
                                                       animationValue);
@@ -1259,15 +1261,11 @@ AsyncCompositionManager::TransformShadowTree(TimeStamp aCurrentFrame,
   // First, compute and set the shadow transforms from OMT animations.
   // NB: we must sample animations *before* sampling pan/zoom
   // transforms.
-  // Use a previous vsync time to make main thread animations and compositor
-  // more in sync with each other.
-  // On the initial frame we use aVsyncTimestamp here so the timestamp on the
-  // second frame are the same as the initial frame, but it does not matter.
   bool wantNextFrame =
     SampleAnimations(root,
                      storage,
-                     !mPreviousFrameTimeStamp.IsNull() ?
+                     mPreviousFrameTimeStamp,
-                       mPreviousFrameTimeStamp : aCurrentFrame);
+                     aCurrentFrame);
 
   if (!wantNextFrame) {
     // Clean up the CompositorAnimationStorage because

gfx/layers/wr/WebRenderBridgeParent.cpp

@@ -1222,18 +1222,17 @@ WebRenderBridgeParent::AdvanceAnimations()
       // refresh mode, on the testing mode animations on the compositor are
       // synchronously composed, so we don't need to worry about the time gap
       // between the main thread and compositor thread.
-      AnimationHelper::SampleAnimations(mAnimStorage, *testingTimeStamp);
+      AnimationHelper::SampleAnimations(mAnimStorage,
+                                        *testingTimeStamp,
+                                        *testingTimeStamp);
       return;
     }
   }
 
   TimeStamp lastComposeTime = mCompositorScheduler->GetLastComposeTime();
-  // if we have already mPreviousTimeStamp, use it since on the compositor the
-  // time in the previous tick is more closer to the main-thread tick time.
   AnimationHelper::SampleAnimations(mAnimStorage,
-      !mPreviousFrameTimeStamp.IsNull()
+                                    mPreviousFrameTimeStamp,
-      ? mPreviousFrameTimeStamp
+                                    lastComposeTime);
-      : lastComposeTime);
 
   // Reset the previous time stamp if we don't already have any running
   // animations to avoid using the time which is far behind for newly