void
nsSMILAnimationController::RewindElements()
{
bool rewindNeeded = false;
for (auto iter = mChildContainerTable.Iter(); !iter.Done(); iter.Next()) {
nsSMILTimeContainer* container = iter.Get()->GetKey();
if (container->NeedsRewind()) {
rewindNeeded = true;
break;
}
}
if (!rewindNeeded)
return;
for (auto iter = mAnimationElementTable.Iter(); !iter.Done(); iter.Next()) {
SVGAnimationElement* animElem = iter.Get()->GetKey();
nsSMILTimeContainer* timeContainer = animElem->GetTimeContainer();
if (timeContainer && timeContainer->NeedsRewind()) {
animElem->TimedElement().Rewind();
}
}
for (auto iter = mChildContainerTable.Iter(); !iter.Done(); iter.Next()) {
iter.Get()->GetKey()->ClearNeedsRewind();
}
}
/*static*/ PLDHashOperator
nsSMILAnimationController::RewindAnimation(AnimationElementPtrKey* aKey,
void* aData)
{
SVGAnimationElement* animElem = aKey->GetKey();
nsSMILTimeContainer* timeContainer = animElem->GetTimeContainer();
if (timeContainer && timeContainer->NeedsRewind()) {
animElem->TimedElement().Rewind();
}
return PL_DHASH_NEXT;
}
void
nsSMILAnimationController::DoMilestoneSamples()
{
// We need to sample the timing model but because SMIL operates independently
// of the frame-rate, we can get one sample at t=0s and the next at t=10min.
//
// In between those two sample times a whole string of significant events
// might be expected to take place: events firing, new interdependencies
// between animations resolved and dissolved, etc.
//
// Furthermore, at any given time, we want to sample all the intervals that
// end at that time BEFORE any that begin. This behaviour is implied by SMIL's
// endpoint-exclusive timing model.
//
// So we have the animations (specifically the timed elements) register the
// next significant moment (called a milestone) in their lifetime and then we
// step through the model at each of these moments and sample those animations
// registered for those times. This way events can fire in the correct order,
// dependencies can be resolved etc.
nsSMILTime sampleTime = INT64_MIN;
while (true) {
// We want to find any milestones AT OR BEFORE the current sample time so we
// initialise the next milestone to the moment after (1ms after, to be
// precise) the current sample time and see if there are any milestones
// before that. Any other milestones will be dealt with in a subsequent
// sample.
nsSMILMilestone nextMilestone(GetCurrentTime() + 1, true);
mChildContainerTable.EnumerateEntries(GetNextMilestone, &nextMilestone);
if (nextMilestone.mTime > GetCurrentTime()) {
break;
}
GetMilestoneElementsParams params;
params.mMilestone = nextMilestone;
mChildContainerTable.EnumerateEntries(GetMilestoneElements, ¶ms);
uint32_t length = params.mElements.Length();
// During the course of a sampling we don't want to actually go backwards.
// Due to negative offsets, early ends and the like, a timed element might
// register a milestone that is actually in the past. That's fine, but it's
// still only going to get *sampled* with whatever time we're up to and no
// earlier.
//
// Because we're only performing this clamping at the last moment, the
// animations will still all get sampled in the correct order and
// dependencies will be appropriately resolved.
sampleTime = std::max(nextMilestone.mTime, sampleTime);
for (uint32_t i = 0; i < length; ++i) {
SVGAnimationElement* elem = params.mElements[i].get();
NS_ABORT_IF_FALSE(elem, "nullptr animation element in list");
nsSMILTimeContainer* container = elem->GetTimeContainer();
if (!container)
// The container may be nullptr if the element has been detached from its
// parent since registering a milestone.
continue;
nsSMILTimeValue containerTimeValue =
container->ParentToContainerTime(sampleTime);
if (!containerTimeValue.IsDefinite())
continue;
// Clamp the converted container time to non-negative values.
nsSMILTime containerTime = std::max<nsSMILTime>(0, containerTimeValue.GetMillis());
if (nextMilestone.mIsEnd) {
elem->TimedElement().SampleEndAt(containerTime);
} else {
elem->TimedElement().SampleAt(containerTime);
}
}
}
}
