flickering rectangle thing

flicker_and_glow.gd

extends Node2D

export(float) var width
export(float) var height

var glow_speed = 0.00125 # per second
export(float) var glow_min_target = 0.425
export(float) var glow_max_target = 0.515
export(float) var glow_mul = 0.05


export(float) var flicker_min = 0.5
export(float) var flicker_max = 2.5
var flicker_timer = 0.0
var flicker_next = 1.0

var cur_flickering

var flicker_steps_min = 1
var flicker_steps_max = 5
var flicker_step_min = 0.1
var flicker_step_max = 0.3

var cur_colour

func _ready():
	randomize()

func _draw():
	draw_rect(Rect2(0, 0, width, height), modulate, true)

func _single_flicker():
	self_modulate.r += 0.75
	self_modulate.g += 0.75
	self_modulate.b += 0.75

func _flicker():
	
	var num_flickers = int(rand_range(flicker_steps_min, flicker_steps_max))
	
	for i in num_flickers:
		var flick_wait = rand_range(flicker_step_min, flicker_step_max)
		while flick_wait >= 0.0:
			var time_passed = yield()
			# printt(flick_wait, time_passed)
			flick_wait -= time_passed
		_single_flicker()
	
	cur_flickering = null

func _process(delta):
	
	if !get_parent().visible: set_process(false)
	
	self_modulate.r = glow_min_target + ((sin(OS.get_ticks_msec() * glow_speed) + 0.5) * glow_mul)
	self_modulate.g = glow_min_target + ((sin(OS.get_ticks_msec() * glow_speed) + 0.5) * glow_mul)
	self_modulate.b = glow_min_target + ((sin(OS.get_ticks_msec() * glow_speed) + 0.5) * glow_mul)
	
	if cur_flickering != null and cur_flickering.is_valid():
		cur_flickering = cur_flickering.resume(delta)
	
	flicker_timer += delta
	if flicker_timer >= flicker_next:
		if cur_flickering == null: cur_flickering = _flicker()
		flicker_next = rand_range(flicker_min, flicker_max)
		flicker_timer = 0