f32/d2/rect.go
func RectFromCircle(c Vec2, r float32) Rectangle {
	return RectWH(c[0]-r, c[1]-r, 2*r, 2*r)
}
func RectFromCircle(c Vec2, r float32) Rectangle {
	return RectWH(c[0]-r, c[1]-r, 2*r, 2*r)
}
func RectFromCircle ( c Vec2 , r float32 ) Rectangle { return RectWH ( c [ 0 ] - r , c [ 1 ] - r , 2 * r , 2 * r ) }
// RectFromCircle returns the minimum rectangle that contains the circle of
// center c and radius r
RectFromCircle returns the minimum rectangle that contains the circle of center c and radius r