public Vector3 GetTangentAt(float t)
{
TBetweenPointsData tbp = GetTBetweenPoints(t);
return(GetTangent(tbp.p1, tbp.p2, tbp.t));
}
// Helper method for finding a pair of points and a corresponding local 't' for given global 't'
TBetweenPointsData GetTBetweenPoints(float t)
{
if (t <= 0)
{
return(new TBetweenPointsData {
p1 = points[0], p2 = points[1], t = 0
});
}
else if (t >= 1)
{
if (close)
{
return(new TBetweenPointsData {
p1 = points[points.Length - 1], p2 = points[0], t = 1
});
}
else
{
return(new TBetweenPointsData {
p1 = points[points.Length - 2], p2 = points[points.Length - 1], t = 1
});
}
}
else
{
float totalPercent = 0;
float curvePercent = 0;
BezierPoint p1 = null;
BezierPoint p2 = null;
int approxResolution = 10;
int safetyCounter = 0;
int maxIters = 10;
while (p1 == null && p2 == null)
{
totalPercent = 0;
int end = close ? points.Length : points.Length - 1;
for (int i = 0; i < end; i++)
{
var pa = points[i];
var pb = points[(i + 1) % points.Length];
curvePercent = ApproximateLength(pa, pb, approxResolution) / length;
if ((totalPercent + curvePercent > t) || Mathf.Abs(t - (totalPercent + curvePercent)) < 5e-6)
{
p1 = pa;
p2 = pb;
break;
}
else
{
totalPercent += curvePercent;
}
}
approxResolution += 10;
if (++safetyCounter >= maxIters)
{
Debug.LogError("BezierCurve couldn't find a point", this);
return(default(TBetweenPointsData));
}
}
if (p1 == null)
{
Debug.LogError("p1 is null");
}
if (p2 == null)
{
Debug.LogError("p2 is null");
}
var ret = new TBetweenPointsData();
ret.p1 = p1;
ret.p2 = p2;
ret.t = (t - totalPercent) / curvePercent;
return(ret);
}
}