public static bool PointOnSegment(Point p, Point a, Point b)
{
if (a.Equals(b))
{
return(p.Equals(a));
}
if (b.X == a.X)
{
return(p.X == a.X && (p.Y >= Math.Min(a.Y, b.Y) && p.Y <= Math.Max(a.Y, b.Y)));
}
if (b.Y == a.Y)
{
return(p.Y == a.Y && (p.X >= Math.Min(a.X, b.X) && p.X <= Math.Max(a.X, b.X)));
}
double tx = (p.X - a.X) / (b.X - a.X);
double ty = (p.Y - a.Y) / (b.Y - a.Y);
return(Math.Abs(tx - ty) <= Constants.Epsilon && tx <= 1 && tx >= 0);
}
public static double getAngle(Point a, Point b, Point c)
{
if (a.Equals(b) || b.Equals(c))
{
return(10);
}
Point VecB = a.Vector(b);
Point VecC = b.Vector(c);
double ang = Math.Acos(dot(VecB, VecC) / (VecB.Magnitude() * VecC.Magnitude()));
double angB = Math.Atan2(VecB.Y, VecB.X);
double angC = Math.Atan2(VecC.Y, VecC.X);
angB += (angB < 0 ? 2 * Math.PI : 0);
angC += (angC < 0 ? 2 * Math.PI : 0);
if (Math.Abs(angC - angB - ang) > 1e-6)
{
ang = ang - 2;
}
ang = (angC - angB) + ((angC - angB) < 0 ? 2 * Math.PI : 0);
return(ang);
}