private void CalculatePath()
{
calculatedPath.Clear();
// Sliders may consist of various subpaths separated by two consecutive vertices
// with the same position. The following loop parses these subpaths and computes
// their shape independently, consecutively appending them to calculatedPath.
int start = 0;
int end = 0;
for (int i = 0; i < ControlPoints.Length(); ++i)
{
end++;
if (i == ControlPoints.Length() - 1 || ControlPoints[i] == ControlPoints[i + 1] && i != ControlPoints.Length() - 2)
{
List <Vector2> cpSpan = ControlPoints.GetRange(start, end - start);
foreach (Vector2 t in CalculateSubpath(cpSpan))
{
if (calculatedPath.Count == 0 || calculatedPath.Last() != t)
{
calculatedPath.Add(t);
}
}
start = end;
}
}
}
/// <summary>
/// Get a point on the curve using interpolation.
/// </summary>
/// <param name="interpolation">A value from 0 to 1.</param>
/// <returns></returns>
public System.Numerics.Vector2 GetPointByInterpolation(float interpolation)
{
if (interpolation < 0 || interpolation > 1)
{
throw new ArgumentException("Value can only range from 0 to 1", nameof(interpolation));
}
if (ControlPoints.Count == 0)
{
throw new ArgumentException("Doesn't contain any points", nameof(ControlPoints));
}
if (ControlPoints.Count == 1)
{
return(ControlPoints[0]);
}
else
{
System.Numerics.Vector2 p1 = GetPointByInterpolationIndependent(ControlPoints.GetRange(0, ControlPoints.Count - 1), interpolation);
System.Numerics.Vector2 p2 = GetPointByInterpolationIndependent(ControlPoints.GetRange(1, ControlPoints.Count - 1), interpolation);
return(System.Numerics.Vector2.Lerp(p1, p2, interpolation));
}
}