korlibs-math-vector/korlibs.math.geom/Angle/Companion/atan2

atan2

inline fun atan2(x: Float, y: Float, up: Vector2D = Vector2D.UP): Angle

inline fun atan2(x: Double, y: Double, up: Vector2D = Vector2D.UP): Angle

inline fun atan2(p: Point, up: Vector2D = Vector2D.UP): Angle