/// <summary>
/// Calculate the outgoing tangent.
/// </summary>
/// <param name="previousControlPoint"></param>
/// <param name="nextControlPoint"></param>
/// <returns></returns>
public Vector3 CalculateDestinationTangent(KochanekBartelsControlPoint previousControlPoint, KochanekBartelsControlPoint nextControlPoint)
{
var factor1 = (1 - Tension) * (1 + Continuity) * (1 + Bias) / 2;
var factor2 = (1 - Tension) * (1 - Continuity) * (1 - Bias) / 2;
return(factor1 * (Position - previousControlPoint.Position) + factor2 * (nextControlPoint.Position - Position));
}
/// <summary>
/// Calculate one segment.
/// </summary>
/// <param name="point1"></param>
/// <param name="point2"></param>
/// <param name="point3"></param>
/// <param name="point4"></param>
/// <param name="steps">Steps for this segement, between point2 and point3.</param>
/// <returns></returns>
private static List <Vector3> InterpolateSegment(KochanekBartelsControlPoint point1, KochanekBartelsControlPoint point2, KochanekBartelsControlPoint point3, KochanekBartelsControlPoint point4, int steps, bool isLastSegment = false)
{
var interpolatedPoints = new List <Vector3>();
Vector3 point2DestinationTangent = point2.CalculateDestinationTangent(point1, point3);
Vector3 point3SourceTangent = point3.CalculateSourceTangent(point2, point4);
for (var i = 0; i < steps; i++)
{
float s;
if (isLastSegment)
{
s = i / (float)(steps - 1);
}
else
{
s = i / (float)(steps);
}
var newPoint = CalculateInterpolatedPoint(point2.Position, point3.Position, point2DestinationTangent, point3SourceTangent, s);
interpolatedPoints.Add(newPoint);
}
return(interpolatedPoints);
}
/// <summary>
/// Insert a control point at index.
/// </summary>
/// <param name="index"></param>
/// <param name="controlPoint"></param>
public SplineModificationInfo InsertControlPoint(int index, KochanekBartelsControlPoint controlPoint)
{
ControlPoints.Insert(index, controlPoint);
if (ControlPoints.Count < 3 && InterpolatedPoints.Count < 2 * Steps)
{
Debug.LogWarning("KochanekBartelsSpline: Control point was added but the line can only be interpolated when there are at least 3 control points.");
return(new SplineModificationInfo(0, 0, 0));
}
else if (ControlPoints.Count == 3 && InterpolatedPoints.Count == Steps)
{
this.SetControlPoints(ControlPoints.ToArray());
return(new SplineModificationInfo(0, Steps, 2 * Steps));
}
else if (ControlPoints.Count == 3)
{
this.SetControlPoints(ControlPoints.ToArray());
return(new SplineModificationInfo(0, 0, 2 * Steps));
}
//determine which segments have to be reinterpolated
int start = (index - 2) >= 0 ? (index - 2) : 0;
int end = (index + 1) <= (ControlPoints.Count - 2) ? (index + 1) : (ControlPoints.Count - 2);
for (int i = start; i <= end; i++)
{
try
{
if (index == ControlPoints.Count - 1)
{
//if we are inserting the control point as the new last element
//dont try to remove the segment before the new control point because it doesnt exist yet
if (i != index - 1)
{
//dont remove at added index so a new segment is added
InterpolatedPoints.RemoveRange(i * Steps, Steps);
}
}
else
{
if (i != index)
{
//dont remove at added index so a new segment is added
InterpolatedPoints.RemoveRange(i * Steps, Steps);
}
}
InterpolatedPoints.InsertRange(i * Steps, InterpolateSegment(i));
}
catch (ArgumentException exception)
{
Debug.LogError("Can't insert control point at index that doesnt exist yet, add instead!\n" + exception);
}
}
return(new SplineModificationInfo(start * Steps, (end - start) * Steps, (end - start + 1) * Steps));
}
/// <summary>
/// Reset the existing control point at index.
/// </summary>
/// <param name="index"></param>
/// <param name="controlPoints"></param>
public SplineModificationInfo SetControlPoint(int index, KochanekBartelsControlPoint controlPoint)
{
ControlPoints[index] = controlPoint;
int start = (index - 2) >= 0 ? (index - 2) : 0;
int end = (index + 1) <= (ControlPoints.Count - 2) ? (index + 1) : (ControlPoints.Count - 2);
for (int i = start; i <= end; i++)
{
try
{
InterpolatedPoints.RemoveRange(i * Steps, Steps);
InterpolatedPoints.InsertRange(i * Steps, InterpolateSegment(i));
}
catch (ArgumentException exception)
{
Debug.LogError("Can't set control point that doesnt exist yet, add instead!\n" + exception);
}
}
return(new SplineModificationInfo(start * Steps, (end - start + 1) * Steps, (end - start + 1) * Steps));
}
/// <summary>
/// Add control point at the end of the curve.
/// </summary>
/// <param name="controlPoint"></param>
public SplineModificationInfo AddControlPoint(KochanekBartelsControlPoint controlPoint)
{
return(InsertControlPoint(ControlPoints.Count, controlPoint));
}