// Compute the circle defined by three points
public void Circumcircle(Point p1, Point p2, Point p3)
{
float orientation;
orientation = PointExtension.Cross(p1, p2, p3);
if (orientation != 0.0)
{
float p1Sq, p2Sq, p3Sq;
float num;
float cx, cy;
p1Sq = p1.x * p1.x + p1.y * p1.y;
p2Sq = p2.x * p2.x + p2.y * p2.y;
p3Sq = p3.x * p3.x + p3.y * p3.y;
num = p1Sq * (p2.y - p3.y) + p2Sq * (p3.y - p1.y) + p3Sq * (p1.y - p2.y);
cx = num / (2.0f * orientation);
num = p1Sq * (p3.x - p2.x) + p2Sq * (p1.x - p3.x) + p3Sq * (p2.x - p1.x);
cy = num / (2.0f * orientation);
center.x = cx;
center.y = cy;
}
radius = center.Distance(p1);
}
void AddTriangle(Point p1, Point p2, Point p3)
{
triangles.Add(new Triangle(p1, p2, p3));
float orientation = PointExtension.Cross(p1, p2, p3);
// Add indices in clockwise order
if (orientation < 0)
{
indices.Add(p1.index);
indices.Add(p2.index);
indices.Add(p3.index);
}
else if (orientation > 0)
{
indices.Add(p3.index);
indices.Add(p2.index);
indices.Add(p1.index);
}
}