draw2dkit/draw2dkit.go
func Circle(path draw2d.PathBuilder, cx, cy, radius float64) {
	path.ArcTo(cx, cy, radius, radius, 0, -math.Pi*2)
	path.Close()
}
func Circle(path draw2d.PathBuilder, cx, cy, radius float64) {
	path.ArcTo(cx, cy, radius, radius, 0, -math.Pi*2)
	path.Close()
}
// Circle draws a circle using a path with center (cx,cy) and radius