public static Polygon Ellipse(Point center, double xRadius, double yRadius)
{
int precision = (int)GMath.Ceiling(GMath.Pi * GMath.Abs(xRadius + yRadius));
if (precision <= 0)
{
return(new Polygon(new[] { center }));
}
double dt = GMath.Tau / precision;
double c = GMath.Cos(dt), s = GMath.Sin(dt);
double x = 1, y = 0, tmp;
var pts = new Point[precision];
for (int i = 0; i < precision; i++)
{
pts[i] = new Point(center.X + x * xRadius, center.Y + y * yRadius);
tmp = x;
x = c * x - s * y;
y = s * tmp + c * y;
}
return(new Polygon(pts));
}
public static Polygon Circle(Point center, double radius)
{
if (radius == 0)
{
return(new Polygon(new[] { center }));
}
int precision = (int)GMath.Ceiling(GMath.Tau * GMath.Abs(radius));
if (precision < 2)
{
precision = 2;
}
return(Regular(precision, radius, center));
}