/// <summary>
/// Determines whether u is in the circumcircle of a, b, and c.
/// </summary>
public static Containment CircumcircleTest(VecRat2 a, VecRat2 b, VecRat2 c, VecRat2 d)
{
Turn t = TurnTestDiscrete(a, b, c);
if (t == Turn.Right)
{
VecRat2 temp = b;
b = c;
c = temp;
}
else if (t == Turn.Linear)
{
throw new Exception("Can't do circumcircle test with a,b,c colinear.");
}
Rational ld = d.LengthSquared();
Rational r = Det3(
a.X - d.X, a.Y - d.Y, a.LengthSquared() - ld,
b.X - d.X, b.Y - d.Y, b.LengthSquared() - ld,
c.X - d.X, c.Y - d.Y, c.LengthSquared() - ld);
if (r > 0)
{
return(Containment.Inside);
}
else if (r == 0)
{
return(Containment.Boundary);
}
else
{
return(Containment.Outside);
}
}
public LineProjectionTransform(SegRat2 s)
{
this.anchor = s.A;
this.dir = s.AB();
this.dot_anchor = dir * anchor;
this.inv_dir_len_sq = 1 / dir.LengthSquared();
}
