Exemple #1
0
bool AndroidFlingPhysics::SampleImpl(const TimeDuration& aDelta,
                                     float* aOutVelocity) {
  mDurationSoFar += aDelta;
  if (mDurationSoFar >= mTargetDuration) {
    return false;
  }

  const float timeRatio =
      mDurationSoFar.ToSeconds() / mTargetDuration.ToSeconds();
  float distanceCoef = 1.0f;
  float velocityCoef = 0.0f;
  gSplineConstants->CalculateCoefficients(timeRatio, &distanceCoef,
                                          &velocityCoef);

  // The caller expects the velocity in pixels per _millisecond_.
  *aOutVelocity =
      velocityCoef * mTargetDistance / mTargetDuration.ToMilliseconds();

  mCurrentPos = mTargetPos * distanceCoef;

  ParentLayerPoint remainder = mTargetPos - mCurrentPos;
  const float threshold = GetThresholdForFlingEnd();
  if (fabsf(remainder.x) < threshold && fabsf(remainder.y) < threshold) {
    return false;
  }

  return true;
}