private double GetPositionX(ref Point start, double relPosition)
{
double resX;
if (relPosition == 0)
{
resX = start.X;
}
else if (relPosition == 1)
{
resX = this.EndPoint.X;
}
else
{
var param = new IterParams()
{
Length = relPosition * GetLength(ref start), StartX = start.X
};
Iterations.NewtonMethod(
delegate(double x, IterParams p)
{
var l1 = EvaluateLengthIntegral(p.StartX);
var l2 = EvaluateLengthIntegral(x);
return(Math.Abs(l1 - l2) - p.Length);
},
param,
////EndPoint.X, ... this is for secant method
start.X + (relPosition * (EndPoint.X - start.X)),
1e-6,
out resX);
}
return(resX);
}