public List <PointFr> SharedVertices(TriangleFr triangle)
{
return(Vertices().SelectMany(v => triangle.Vertices().Where(v2 => v == v2), (v, v2) => v).ToList());
}
public bool ContainsInCircumcircle(PointFr p, TriangleFr superTriangle = null)
{
var vertices = Vertices().OrderBy(pnt => pnt.X).ThenBy(pnt => pnt.Y).ToList();
var p1 = vertices[0];
var p2 = vertices[1];
var p3 = vertices[2];
if ((p1.Y - p2.Y).Abs() == 0 && (p2.Y - p3.Y).Abs() == 0) // < double.Epsilon
{
return(false);
}
if (superTriangle != null)
{
var sharedVertices = SharedVertices(superTriangle).ToList();
var otherVertices = vertices.Except(sharedVertices).ToList();
if (sharedVertices.Count == 1)
{
return(!new LineSegmentFr(p, sharedVertices.Single()).Intersects(new LineFr(otherVertices[0], otherVertices[1])));
}
if (sharedVertices.Count == 2)
{
return(!new LineSegmentFr(p, sharedVertices.First()).Intersects(new LineFr(new LineFr(sharedVertices[0], sharedVertices[1]).Slope, otherVertices[0])));
}
}
Fraction m1, m2;
Fraction mx1, mx2;
Fraction my1, my2;
Fraction xc, yc;
if ((p2.Y - p1.Y).Abs() == 0) // < double.Epsilon
{
m2 = -(p3.X - p2.X) / (p3.Y - p2.Y);
mx2 = (p2.X + p3.X) * 0.5;
my2 = (p2.Y + p3.Y) * 0.5; // Oblicz środek okręgu opisanego (xc, yc)
xc = (p2.X + p1.X) * 0.5;
yc = m2 * (xc - mx2) + my2;
}
else if ((p3.Y - p2.Y).Abs() == 0) // < double.Epsilon
{
m1 = -(p2.X - p1.X) / (p2.Y - p1.Y);
mx1 = (p1.X + p2.X) * 0.5;
my1 = (p1.Y + p2.Y) * 0.5;
xc = (p3.X + p2.X) * 0.5; // Oblicz środek okręgu opisanego (xc,yc)
yc = m1 * (xc - mx1) + my1;
}
else
{
m1 = -(p2.X - p1.X) / (p2.Y - p1.Y);
m2 = -(p3.X - p2.X) / (p3.Y - p2.Y);
mx1 = (p1.X + p2.X) * 0.5;
mx2 = (p2.X + p3.X) * 0.5;
my1 = (p1.Y + p2.Y) * 0.5;
my2 = (p2.Y + p3.Y) * 0.5;
xc = (m1 * mx1 - m2 * mx2 + my2 - my1) / (m1 - m2); // Oblicz środek okręgu opisanego (xc,yc)
yc = m1 * (xc - mx1) + my1;
}
var dx = p2.X - xc;
var dy = p2.Y - yc;
var rsqr = dx * dx + dy * dy; //double r = Math.Sqrt(rsqr); // Promień okręgu opisanego
dx = p.X - xc;
dy = p.Y - yc;
var drsqr = dx * dx + dy * dy;
return(drsqr <= rsqr);
}
public bool SharesVertexWith(TriangleFr triangle)
{
return(Vertices().Any(v => triangle.Vertices().Any(v2 => v == v2)));
}
