Sierpinski Triangle - Godot

Canvas.gd

extends Node2D

#var axiom = "F++F++F++"
var axiom = "A"
var angle_step = deg_to_rad(60)
var iteration = 1
var step_length: float = 64
var frame = Rect2(0, 0, 0, 0)

var rules = {
	"F": "F-F++F-F",
	"A": "B-A-B",
	"B": "A+B+A"
}

# Called when the node enters the scene tree for the first time.
func _ready():
	pass # Replace with function body.

# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta):
	pass

func _draw():
	var start_x = 0 if iteration % 2 == 1 else (get_window().size.x  * (1 / scale.y))
	var start_y = (get_window().size.y) * (1 / scale.y)
	var position = Vector2(start_x, start_y)
	var angle = deg_to_rad(90) if iteration % 2 == 1 else deg_to_rad(270)
	var current = LNode.new(angle, position)
	
	for command in axiom:
		match(command):
			"F", "A", "B":
				var delta = Vector2.UP.rotated(current.angle) * step_length
				var end_point = current.position + delta
				draw_line(current.position, end_point, Color.GREEN, 1.0 / scale.x, true)
				current.position = end_point
			"+":
				current.angle -= angle_step
			"-":
				current.angle += angle_step
			
		frame.size.x = max(current.position.x - start_x, frame.size.x)
		frame.size.y = max(current.position.y - start_y, frame.size.y)
		frame.position.x = min(current.position.x - start_x, frame.position.x)
		frame.position.x = min(current.position.y - start_y, frame.position.y)

func _on_button_pressed():
	iteration += 1
	var new_axiom = ""
	for command in axiom:
		var rule = rules.get(command, command)
		new_axiom += rule
	
	axiom = new_axiom
	queue_redraw()

func _on_shrink_pressed():
	scale *= 0.75
	queue_redraw()