/// <summary>
/// Construct ellipse from two conjugate diameters, and set
/// Axis0 to the major axis and Axis1 to the minor axis.
/// The algorithm was constructed from first principles.
/// Also computes the squared lengths of the major and minor
/// half axis.
/// </summary>
public static __et__ FromConjugateDiameters(__vt__ center, /*# if (d == 3) { */ __vt__ normal, /*# } */ __vt__ a, __vt__ b,
out double major2, out double minor2)
{
var ab = __vt__.Dot(a, b);
double a2 = a.LengthSquared, b2 = b.LengthSquared;
if (ab.IsTiny())
{
if (a2 >= b2)
{
major2 = a2; minor2 = b2; return(new __et__(center, /*# if (d == 3) { */ normal, /*# } */ a, b));
}
else
{
major2 = b2; minor2 = a2; return(new __et__(center, /*# if (d == 3) { */ normal, /*# } */ b, a));
}
}
else
{
var t = 0.5 * Fun.Atan2(2 * ab, a2 - b2);
double ct = Fun.Cos(t), st = Fun.Sin(t);
__vt__ v0 = a * ct + b * st, v1 = b * ct - a * st;
a2 = v0.LengthSquared; b2 = v1.LengthSquared;
if (a2 >= b2)
{
major2 = a2; minor2 = b2; return(new __et__(center, /*# if (d == 3) { */ normal, /*# } */ v0, v1));
}
else
{
major2 = b2; minor2 = a2; return(new __et__(center, /*# if (d == 3) { */ normal, /*# } */ v1, v0));
}
}
}
/// <summary>
/// Get count points on the circumference of the ellipse.
/// </summary>
public __vt__[] GetPoints(int count)
{
var array = new __vt__[count];
var c = Center;
ForEachVector(count, (i, v) => array[i] = c + v);
return(array);
}
public __et__(__vt__ center, /*# if (d == 3) { */ __vt__ normal, /*# } */ __vt__ axis0, __vt__ axis1)
{
Center = center;
//# if (d == 3) {
Normal = normal;
//# }
Axis0 = axis0;
Axis1 = axis1;
}
