Point2D Quadratic(float t, KeyFrame first, KeyFrame second, KeyFrame third)
{
float dt0 = (first.t - second.t) * (first.t - third.t);
float dt1 = (second.t - first.t) * (second.t - third.t);
float dt2 = (third.t - first.t) * (third.t - second.t);
Point2D p0 = first.point * ((t - second.t) * (t - third.t)) / dt0;
Point2D p1 = second.point * ((t - first.t) * (t - third.t)) / dt1;
Point2D p2 = third.point * ((t - first.t) * (t - second.t)) / dt2;
return p0 + p1 + p2;
}
public override KeyFrame Calculate(float timestamp, List<KeyFrame> source)
{
if (source.Count == 0 || source.Count < 2) return new KeyFrame();
KeyFrame result = source[0];
int neighbor = FindNearKeyFrame(timestamp, source);
if (neighbor >= 0)
{
KeyFrame first = (neighbor == source.Count - 1) ? source[neighbor - 1] : source[neighbor];
KeyFrame second = (neighbor == source.Count - 1) ? source[neighbor] : source[neighbor + 1];
Point2D interp_point = Lerp(timestamp, first, second);
result = new KeyFrame(timestamp, interp_point);
}
return result;
}
public override KeyFrame Calculate(float timestamp, List<KeyFrame> source)
{
if (source.Count == 0 || source.Count < 3) return new KeyFrame();
KeyFrame result = source[0];
int neighbor = FindNearKeyFrame(timestamp, source);
if (neighbor >= 0 && neighbor < (source.Count - 1))
{
KeyFrame first = new KeyFrame();
KeyFrame second = new KeyFrame();
KeyFrame third = new KeyFrame();
if (neighbor == 0)
{
first = source[0];
second = source[1];
third = source[2];
}
else if (neighbor == source.Count - 1)
{
first = source[source.Count - 3];
second = source[source.Count - 2];
third = source[source.Count - 1];
}
else if (neighbor > 0)
{
first = source[neighbor - 1];
second = source[neighbor];
third = source[neighbor + 1];
}
Point2D interp_point = Quadratic(timestamp, first, second, third);
result = new KeyFrame(timestamp, interp_point);
}
return result;
}
public override KeyFrame Calculate(float timestamp, List <KeyFrame> source)
{
if (source.Count == 0 || source.Count < 2)
{
return(new KeyFrame());
}
KeyFrame result = source[0];
int neighbor = FindNearKeyFrame(timestamp, source);
if (neighbor >= 0)
{
KeyFrame first = (neighbor == source.Count - 1) ? source[neighbor - 1] : source[neighbor];
KeyFrame second = (neighbor == source.Count - 1) ? source[neighbor] : source[neighbor + 1];
Point2D interp_point = Lerp(timestamp, first, second);
result = new KeyFrame(timestamp, interp_point);
}
return(result);
}
public override KeyFrame Calculate(float timestamp, List<KeyFrame> source)
{
if (source.Count == 0 || source.Count < 4) return new KeyFrame();
KeyFrame result = source[0];
int neighbor = FindNearKeyFrame(timestamp, source);
if (neighbor >= 0 && neighbor < (source.Count - 1))
{
Point2D P0 = (neighbor == 0) ? source[neighbor].point : source[neighbor - 1].point;
Point2D P1 = source[neighbor].point;
Point2D P2 = source[neighbor + 1].point;
Point2D P3 = (neighbor + 2 > source.Count - 1) ? source[neighbor + 1].point : source[neighbor + 2].point;
float dt = (timestamp - source[neighbor].t) / (source[neighbor + 1].t - source[neighbor].t);
Point2D interp_point = HermiteInterpolate(dt, P0, P1, P2, P3);
result = new KeyFrame(timestamp, interp_point);
}
return result;
}
public virtual KeyFrame Calculate(float timestamp, List <KeyFrame> source)
{
KeyFrame result = new KeyFrame();
return(result);
}
public virtual KeyFrame Calculate(float timestamp, List<KeyFrame> source)
{
KeyFrame result = new KeyFrame();
return result;
}
Point2D Lerp(float t, KeyFrame first, KeyFrame second)
{
float alpha = (t - first.t) / (second.t - first.t);
return first.point + (second.point - first.point) * alpha;
}
Point2D Lerp(float t, KeyFrame first, KeyFrame second)
{
float alpha = (t - first.t) / (second.t - first.t);
return(first.point + (second.point - first.point) * alpha);
}