interface Draggable : Role {

    fun mass() : float

    fun scale(scale: float)

    fun scale(scale: Vector2)
}

abstract class AbstractDraggable : ActionRole(), Draggable {

    override fun mass() = actor.body.mass

    override fun scale(scale: float) {
        scale( Vector2( scale, scale ) )
    }

    override fun scale(scale : Vector2) {
        actor.scale *= scale
    }
}