ease_towards_direction

/// ease_towards_direction(target, rate, easing)
//
//  Rotates the calling instance towards the target direction,
//  at a given rate and easing. Easing makes the turn complete
//  more gradually.
//
//      target      angle to turn towards
//      rate        maximum turning rate
//      easing      amount of easing, 0..1, no easing to infinite easing
//
/// GMLscripts.com/license
{
    direction += median(-argument1, argument1, (1-argument2) * angle_difference(argument0, direction));
}