Rotate direction by 45 degree increments

Question

extends Node2D

const SPEED = 200

var velocity = Vector2(0, -1)
var angle = 0
var turn = 0.25 * PI
var time = 32

onready var target = $Sprite

func _ready():
    angle = velocity.angle()

func _physics_process(delta):

    $Sprite.position = get_global_mouse_position()

    time -= 1

    if time == 0:
        var desired = (target.position - $Sprite2.position).normalized()
        desired = desired.angle()

        if desired < angle:
            angle -= turn
        elif desired > angle:
            angle += turn

        velocity = Vector2(round(cos(angle)), round(sin(angle)))

        time = 4

    $Sprite2.position += velocity * (SPEED * delta)

Trying to get one sprite to track another but only allowing it to turn in 45 degree increments. At first, it looks as it it's going to work. Then the tracking sprite just screws off and wanders of screen.

Answer 1

For snapping the desired angle, you can use stepify().

For example, this arrow points towards the mouse, but only in 45 degree increments:

extends Node2D

func _process(delta):
    var a = position.direction_to(get_global_mouse_position()).angle()
    rotation = stepify(a, PI/4)

Comments

This works perfectly, but how would I make the angle rotate with a delay like a homing missile?