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	 680815cd6e
			
		
	
	
		680815cd6e
		
	
	
	
	
		
			
			This patch was generated automatically by the "modeline.py" script, available here: https://github.com/amccreight/moz-source-tools/blob/master/modeline.py For every file that is modified in this patch, the changes are as follows: (1) The patch changes the file to use the exact C++ mode lines from the Mozilla coding style guide, available here: https://developer.mozilla.org/en-US/docs/Mozilla/Developer_guide/Coding_Style#Mode_Line (2) The patch deletes any blank lines between the mode line & the MPL boilerplate comment. (3) If the file previously had the mode lines and MPL boilerplate in a single contiguous C++ comment, then the patch splits them into separate C++ comments, to match the boilerplate in the coding style. MozReview-Commit-ID: EuRsDue63tK --HG-- extra : rebase_source : 3356d4b80ff6213935192e87cdbc9103fec6084c
		
			
				
	
	
		
			110 lines
		
	
	
	
		
			3.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			110 lines
		
	
	
	
		
			3.7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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| /* vim: set ts=8 sts=2 et sw=2 tw=80: */
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| /* This Source Code Form is subject to the terms of the Mozilla Public
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|  * License, v. 2.0. If a copy of the MPL was not distributed with this
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|  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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| 
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| #include "ScrollAnimationMSDPhysics.h"
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| #include "gfxPrefs.h"
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| 
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| using namespace mozilla;
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| 
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| ScrollAnimationMSDPhysics::ScrollAnimationMSDPhysics(const nsPoint& aStartPos)
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|  : mStartPos(aStartPos)
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|  , mModelX(0, 0, 0, gfxPrefs::SmoothScrollMSDPhysicsRegularSpringConstant(), 1)
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|  , mModelY(0, 0, 0, gfxPrefs::SmoothScrollMSDPhysicsRegularSpringConstant(), 1)
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|  , mIsFirstIteration(true)
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| {
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| }
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| 
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| void
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| ScrollAnimationMSDPhysics::Update(const TimeStamp& aTime,
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|                                   const nsPoint& aDestination,
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|                                   const nsSize& aCurrentVelocity)
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| {
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|   double springConstant = ComputeSpringConstant(aTime);
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| 
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|   // mLastSimulatedTime is the most recent time that this animation has been
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|   // "observed" at. We don't want to update back to a state in the past, so we
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|   // set mStartTime to the more recent of mLastSimulatedTime and aTime.
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|   // aTime can be in the past if we're processing an input event whose internal
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|   // timestamp is in the past.
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|   if (mLastSimulatedTime && aTime < mLastSimulatedTime) {
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|     mStartTime = mLastSimulatedTime;
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|   } else {
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|     mStartTime = aTime;
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|   }
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| 
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|   if (!mIsFirstIteration) {
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|     mStartPos = PositionAt(mStartTime);
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|   }
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| 
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|   mLastSimulatedTime = mStartTime;
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|   mDestination = aDestination;
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|   mModelX = AxisPhysicsMSDModel(mStartPos.x, aDestination.x,
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|                                 aCurrentVelocity.width, springConstant, 1);
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|   mModelY = AxisPhysicsMSDModel(mStartPos.y, aDestination.y,
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|                                 aCurrentVelocity.height, springConstant, 1);
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|   mIsFirstIteration = false;
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| }
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| 
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| double
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| ScrollAnimationMSDPhysics::ComputeSpringConstant(const TimeStamp& aTime)
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| {
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|   if (!mPreviousEventTime) {
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|     mPreviousEventTime = aTime;
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|     mPreviousDelta = TimeDuration();
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|     return gfxPrefs::SmoothScrollMSDPhysicsMotionBeginSpringConstant();
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|   }
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| 
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|   TimeDuration delta = aTime - mPreviousEventTime;
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|   TimeDuration previousDelta = mPreviousDelta;
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| 
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|   mPreviousEventTime = aTime;
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|   mPreviousDelta = delta;
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| 
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|   double deltaMS = delta.ToMilliseconds();
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|   if (deltaMS >= gfxPrefs::SmoothScrollMSDPhysicsContinuousMotionMaxDeltaMS()) {
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|     return gfxPrefs::SmoothScrollMSDPhysicsMotionBeginSpringConstant();
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|   }
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| 
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|   if (previousDelta &&
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|       deltaMS >= gfxPrefs::SmoothScrollMSDPhysicsSlowdownMinDeltaMS() &&
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|       deltaMS >= previousDelta.ToMilliseconds() * gfxPrefs::SmoothScrollMSDPhysicsSlowdownMinDeltaRatio()) {
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|     // The rate of events has slowed (the time delta between events has
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|     // increased) enough that we think that the current scroll motion is coming
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|     // to a stop. Use a stiffer spring in order to reach the destination more
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|     // quickly.
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|     return gfxPrefs::SmoothScrollMSDPhysicsSlowdownSpringConstant();
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|   }
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| 
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|   return gfxPrefs::SmoothScrollMSDPhysicsRegularSpringConstant();
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| }
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| 
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| void
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| ScrollAnimationMSDPhysics::SimulateUntil(const TimeStamp& aTime)
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| {
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|   if (!mLastSimulatedTime || aTime < mLastSimulatedTime) {
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|     return;
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|   }
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|   TimeDuration delta = aTime - mLastSimulatedTime;
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|   mModelX.Simulate(delta);
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|   mModelY.Simulate(delta);
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|   mLastSimulatedTime = aTime;
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| }
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| 
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| nsPoint
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| ScrollAnimationMSDPhysics::PositionAt(const TimeStamp& aTime)
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| {
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|   SimulateUntil(aTime);
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|   return nsPoint(NSToCoordRound(mModelX.GetPosition()),
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|                  NSToCoordRound(mModelY.GetPosition()));
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| }
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| 
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| nsSize
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| ScrollAnimationMSDPhysics::VelocityAt(const TimeStamp& aTime)
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| {
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|   SimulateUntil(aTime);
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|   return nsSize(NSToCoordRound(mModelX.GetVelocity()),
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|                 NSToCoordRound(mModelY.GetVelocity()));
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| }
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