/* -*- 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_AndroidFlingPhysics_h_
#define mozilla_layers_AndroidFlingPhysics_h_
#include "AsyncPanZoomController.h"
#include "Units.h"
#include "mozilla/Assertions.h"
namespace mozilla {
namespace layers {
class AndroidFlingPhysics {
public:
void Init(
const ParentLayerPoint& aVelocity,
float aPLPPI);
void Sample(
const TimeDuration& aDelta, ParentLayerPoint* aOutVelocity,
ParentLayerPoint* aOutOffset);
static void InitializeGlobalState();
private:
// Returns false if the animation should end.
bool SampleImpl(
const TimeDuration& aDelta,
float* aOutVelocity);
// Information pertaining to the current fling.
// This is initialized on each call to Init().
ParentLayerCoord mVelocity;
// diagonal velocity (length of velocity vector)
TimeDuration mTargetDuration;
TimeDuration mDurationSoFar;
ParentLayerPoint mLastPos;
ParentLayerPoint mCurrentPos;
ParentLayerCoord mTargetDistance;
// diagonal distance
ParentLayerPoint mTargetPos;
// really a target *offset* relative to the
// start position, which we don't track
ParentLayerPoint mDeltaNorm;
// mTargetPos with length normalized to 1
};
}
// namespace layers
}
// namespace mozilla
#endif // mozilla_layers_AndroidFlingPhysics_h_
