/**
* Draw a filled ellipse with given semimajor and semiminor axes, centred on (x, y).
*
* @param x the x-coordinate of the centre of the ellipse
* @param y the y-coordinate of the centre of the ellipse
* @param semiMajorAxis is the semimajor axis of the ellipse
* @param semiMinorAxis is the semiminor axis of the ellipse
* @throws RuntimeException if either of the axes are negative
*/
public static void filledEllipse(double x, double y, double semiMajorAxis, double semiMinorAxis) {
offscreen.fill(ShapeAssist.ellipse(x, y, semiMajorAxis, semiMinorAxis));
draw();
}
