/// <summary>
/// Adjusts the factor based on the curve type from the given key.
/// </summary>
public static float AdjustFactor(float factor, SpriterKey key)
{
switch (key.CurveType)
{
case SpriterCurveType.Instant:
factor = 0.0f;
break;
case SpriterCurveType.Linear:
break;
case SpriterCurveType.Quadratic:
factor = MathHelper.Bezier(0.0f, key.C1, 1.0f, factor);
break;
case SpriterCurveType.Cubic:
factor = MathHelper.Bezier(0.0f, key.C1, key.C2, 1.0f, factor);
break;
case SpriterCurveType.Quartic:
factor = MathHelper.Bezier(0.0f, key.C1, key.C2, key.C3, 1.0f, factor);
break;
case SpriterCurveType.Quintic:
factor = MathHelper.Bezier(0.0f, key.C1, key.C2, key.C3, key.C4, 1.0f, factor);
break;
case SpriterCurveType.Bezier:
factor = MathHelper.Bezier2D(key.C1, key.C2, key.C3, key.C4, factor);
break;
}
return(factor);
}
/// <summary>
/// Adjusts the animation time taking into account key curve types.
/// </summary>
public static float AdjustTime(float targetTime, SpriterKey keyA, SpriterKey keyB, float animationLength)
{
float nextTime = GetNextTime(keyA, keyB, animationLength);
float factor = GetFactor(keyA, keyB, animationLength, targetTime);
return(MathHelper.Linear(keyA.Time, nextTime, factor));
}
/// <summary>
/// Gets next time for the two keys based on relative keys timeline position.
/// </summary>
private static float GetNextTime(SpriterKey keyA, SpriterKey keyB, float animationLength)
{
if (keyA.Time < keyB.Time)
{
return(keyB.Time);
}
else if (keyB.Time + animationLength == keyA.Time)
{
return(keyA.Time + animationLength);
}
else
{
return(animationLength);
}
}
/// <summary>
/// Gets the interpolation factor for the two keys. Takes into account key curve types.
/// </summary>
public static float GetFactor(SpriterKey keyA, SpriterKey keyB, float animationLength, float targetTime)
{
float timeA = keyA.Time;
float timeB = keyB.Time;
if (timeA > timeB)
{
timeB += animationLength;
if (targetTime < timeA)
{
targetTime += animationLength;
}
}
float factor = MathHelper.GetFactor(timeA, timeB, targetTime);
factor = AdjustFactor(factor, keyA);
return(factor);
}
