const TEXTURE_PATHS = [
    "res://img/gun_barrel_0.png",
    "res://img/gun_barrel_1.png",
    "res://img/gun_barrel_2.png",
    "res://img/gun_barrel_3.png",
    "res://img/gun_barrel_4.png",
    "res://img/gun_barrel_5.png",
    "res://img/gun_barrel_6.png",
]
var textures = []

func _ready():
    textures.resize(7)
    for i in range(0, 7):
        textures[i] = load(TEXTURE_PATHS[i])

func change_sprite_texture(angle):
    var index = ...
    $Sprite.set_texture(textures[index])