C++ TimeDuration::MultDouble方法代码示例

// https://w3c.github.io/web-animations/#finish-an-animation
void
Animation::Finish(ErrorResult& aRv)
{
  if (mPlaybackRate == 0 ||
      (mPlaybackRate > 0 && EffectEnd() == TimeDuration::Forever())) {
    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
    return;
  }

  AutoMutationBatchForAnimation mb(*this);

  // Seek to the end
  TimeDuration limit =
    mPlaybackRate > 0 ? TimeDuration(EffectEnd()) : TimeDuration(0);
  bool didChange = GetCurrentTime() != Nullable<TimeDuration>(limit);
  SilentlySetCurrentTime(limit);

  // If we are paused or play-pending we need to fill in the start time in
  // order to transition to the finished state.
  //
  // We only do this, however, if we have an active timeline. If we have an
  // inactive timeline we can't transition into the finished state just like
  // we can't transition to the running state (this finished state is really
  // a substate of the running state).
  if (mStartTime.IsNull() &&
      mTimeline &&
      !mTimeline->GetCurrentTime().IsNull()) {
    mStartTime.SetValue(mTimeline->GetCurrentTime().Value() -
                        limit.MultDouble(1.0 / mPlaybackRate));
    didChange = true;
  }

  // If we just resolved the start time for a pause or play-pending
  // animation, we need to clear the task. We don't do this as a branch of
  // the above however since we can have a play-pending animation with a
  // resolved start time if we aborted a pause operation.
  if (!mStartTime.IsNull() &&
      (mPendingState == PendingState::PlayPending ||
       mPendingState == PendingState::PausePending)) {
    if (mPendingState == PendingState::PausePending) {
      mHoldTime.SetNull();
    }
    CancelPendingTasks();
    didChange = true;
    if (mReady) {
      mReady->MaybeResolve(this);
    }
  }
  UpdateTiming(SeekFlag::DidSeek, SyncNotifyFlag::Sync);
  if (didChange && IsRelevant()) {
    nsNodeUtils::AnimationChanged(this);
  }
  PostUpdate();
}

// http://w3c.github.io/web-animations/#silently-set-the-current-time
void
Animation::SilentlySetCurrentTime(const TimeDuration& aSeekTime)
{
  if (!mHoldTime.IsNull() ||
      mStartTime.IsNull() ||
      !mTimeline ||
      mTimeline->GetCurrentTime().IsNull() ||
      mPlaybackRate == 0.0) {
    mHoldTime.SetValue(aSeekTime);
    if (!mTimeline || mTimeline->GetCurrentTime().IsNull()) {
      mStartTime.SetNull();
    }
  } else {
    mStartTime.SetValue(mTimeline->GetCurrentTime().Value() -
                          (aSeekTime.MultDouble(1 / mPlaybackRate)));
  }

  mPreviousCurrentTime.SetNull();
}

  virtual void ScheduleNextTick(TimeStamp aNowTime)
  {
    static const TimeDuration kMinSaneInterval = TimeDuration::FromMilliseconds(3); // 330Hz
    static const TimeDuration kMaxSaneInterval = TimeDuration::FromMilliseconds(44); // 23Hz
    static const TimeDuration kNegativeMaxSaneInterval = TimeDuration::FromMilliseconds(-44); // Saves conversions for abs interval
    TimeStamp lastVblank;
    TimeDuration vblankInterval;

    if (!mPreferHwTiming ||
        NS_OK != GetVBlankInfo(lastVblank, vblankInterval) ||
        vblankInterval > kMaxSaneInterval ||
        vblankInterval < kMinSaneInterval ||
        (aNowTime - lastVblank) > kMaxSaneInterval ||
        (aNowTime - lastVblank) < kNegativeMaxSaneInterval) {
      // Use the default timing without vsync
      PreciseRefreshDriverTimer::ScheduleNextTick(aNowTime);
      return;
    }

    TimeStamp newTarget = lastVblank + vblankInterval; // Base target

    // However, timer callback might return early (or late, but that wouldn't bother us), and vblankInterval
    // appears to be slightly (~1%) different on each call (probably the OS measuring recent actual interval[s])
    // and since we don't want to re-target the same vsync, we keep advancing in vblank intervals until we find the
    // next safe target (next vsync, but not within 10% interval of previous target).
    // This is typically 0 or 1 iteration:
    // If we're too early, next vsync would be the one we've already targeted (1 iteration).
    // If the timer returned late, no iteration will be required.

    const double kSameVsyncThreshold = 0.1;
    while (newTarget <= mTargetTime + vblankInterval.MultDouble(kSameVsyncThreshold)) {
      newTarget += vblankInterval;
    }

    // To make sure we always hit the same "side" of the signal:
    // round the delay up (by adding 1, since we later floor) and add a little (10% by default).
    // Note that newTarget doesn't change (and is the next vblank) as a reference when we're back.
    static const double kDefaultPhaseShiftPercent = 10;
    static const double phaseShiftFactor = 0.01 *
      (Preferences::GetInt("layout.frame_rate.vsync.phasePercentage", kDefaultPhaseShiftPercent) % 100);

    double phaseDelay = 1.0 + vblankInterval.ToMilliseconds() * phaseShiftFactor;

    // ms until the next time we should tick
    double delayMs = (newTarget - aNowTime).ToMilliseconds() + phaseDelay;

    // Make sure the delay is never negative.
    uint32_t delay = static_cast<uint32_t>(delayMs < 0 ? 0 : delayMs);

    // log info & lateness
    LOG("[%p] precise dwm-vsync timer last tick late by %f ms, next tick in %d ms",
        this,
        (aNowTime - mTargetTime).ToMilliseconds(),
        delay);

    // then schedule the timer
    LOG("[%p] scheduling callback for %d ms (2)", this, delay);
    mTimer->InitWithFuncCallback(TimerTick, this, delay, nsITimer::TYPE_ONE_SHOT);

    mTargetTime = newTarget;
  }