private void drawStar(double r) {
Surface surface = getPrimarySurface();
surface.save();
ShapeBuilder shapeBuilder = new ShapeBuilder().moveTo(r, 0);
for (int i = 0; i < 9; i++) {
shapeBuilder.rotate(Math.PI / 5);
if (i % 2 == 0) {
shapeBuilder.drawLineTo((r / 0.525731) * 0.200811, 0);
} else {
shapeBuilder.drawLineTo(r, 0);
}