/// <summary>
/// Gets inertial motion parameters: distance and duration.
/// </summary>
/// <param name="hostBounds">The host bounds.</param>
/// <param name="windowBounds">The window bounds.</param>
/// <returns>
/// The inertial motion parameters: distance and duration.
/// </returns>
public InertialMotion GetInertialMotionParameters(Rect hostBounds, Rect windowBounds)
{
if (mouseTrails.Count < 2) return null;
var mouseTrailsArray = mouseTrails.ToArray();
Point startPosition = mouseTrailsArray[0].Position;
DateTime startTime = mouseTrailsArray[0].Timestamp;
Point endPosition = mouseTrailsArray[mouseTrails.Count - 1].Position;
DateTime endTime = mouseTrailsArray[mouseTrails.Count - 1].Timestamp;
double timeBetweenNowAndLastMove = (DateTime.Now - endTime).TotalMilliseconds;
Vector2 vector = new Vector2(startPosition, endPosition);
if (timeBetweenNowAndLastMove < DELAY_BEFORE_MOUSE_UP_IN_MILLISECONDS && !vector.IsZero)
{
double time = (endTime - startTime).TotalSeconds;
time = (time == 0) ? 0.001 : time;
double distance = vector.Length / pixelsPerMeter;
double intialVelocity = distance / time;
double expectedDistance = ((intialVelocity * intialVelocity) / (2 * COEFFICIENT_OF_SLIDING_FRICTION * GRAVITATIONAL_ACCELERATION));
double expectedTime = (2 * expectedDistance) / intialVelocity;
double shiftX = Math.Round(vector.LengthX * expectedDistance / distance);
double shiftY = Math.Round(vector.LengthY * expectedDistance / distance);
// New Inertial Motion Vector
Vector2 imVector = new Vector2(endPosition, shiftX, shiftY).Round();
double expectedLength = imVector.Length;
Rect bounds = hostBounds.Add(-windowBounds.Width, -windowBounds.Height);
if (bounds.Contains(endPosition))
{
imVector = EnsureEndPointInBounds(imVector, bounds).Round();
}
else if (hostBounds.Contains(endPosition))
{
imVector = EnsureEndPointInBounds(imVector, hostBounds).Round();
}
// Reduce expected time if the Inertial Motion Vector was truncated by the bounds
double realTime = (expectedLength == 0) ? 0 : (expectedTime * imVector.Length / expectedLength);
var motion = new InertialMotion()
{
Seconds = realTime,
EndPosition = imVector.End,
EasingFunction = new CubicEase()
{
EasingMode = EasingMode.EaseOut
}
};
return motion;
}
return null;
}
