public static Point2d[] EllipseEllipse(Ellipse2d el1, Ellipse2d el2)
{
//reduce this problem to a circle-ellipse problem by
//rotating ellipse 1 down, scaling it to circle and then
//rotate ellipse2 down.
Transform2d tr = Transform2d.Rotate(-el1.Rotation) * Transform2d.Stretch(1.0, 1.0 / el1.Ratio);
//dont modify originals:
el1 = new Ellipse2d(el1);
el2 = new Ellipse2d(el2);
el1.Transform(tr);
el2.Transform(tr);
Point2d[] res = EllipseCircle(el2, new Circle2d(el1.X, el1.Y, el1.MajorRadius));
if (res == null)
{
return(null);
}
Transform2d trinv = (tr).Inversed;
for (int l = 0; l < res.Length; l++)
{
res[l] = res[l].GetTransformed(trinv);
}
return(res);
}