/**
    Moves an Actor along an n-sided polygon.
    The code includes diffent ways to connect each point of the polygon.
    "regular", rounded inwards/outwards, star-shaped.
*/
class PolygonRole : ActionRole {

    @Attribute
    var sides = 5

    @Attribute
    var sideLength = 200

    override fun createAction() : Action {

        val path = Path().apply {
            for (i in 0 until sides) {
                // by is a vector length `sideLength`, in the direction we need to move for this side of the polygon.
                val by = Angle.degrees( 360 / sides * i ).vector() * sideLength

                // Choose how you want to connect the points of the polygon.
                // Keep only ONE example uncommented !                

                // A straight line between each point of the polygon
                //lineBy( by )

                // Or use a slightly concave curve instead
                //circularArcBy( by, sideLength * 1.2, false, false )
                
                // Or use a slightly convex curve
                //circularArcBy( by, sideLength * 1.2, false, true )

                // Or A star shape, by using two lines, on each side of the polygon.
                val inwards = by.perpendicular() * 0.2 // 0.2 determines how pointed the star is.
                lineBy( by/2 + inwards )
                lineBy( by/2 - inwards )
            }
        }

        return path.relativeTo( actor.position ).follow( actor.position, 5 ).forever()
    }


}