extends ReferenceRect
const battle_bg_shader = preload('res://shaders/tilemap_shader.gdshader')

onready var background := $background
var bg: SpriteLoader.BattleBackground
var pal_l: int
var atlas_l: int

# Called when the node enters the scene tree for the first time.
func _ready() -> void:
	var battle_bg_mat := ShaderMaterial.new()
	battle_bg_mat.shader = battle_bg_shader
	background.material = battle_bg_mat
	set_bg(1)

func set_bg(index: int) -> void:
	self.bg = SpriteLoader.battle_backgrounds[index]
	self.pal_l = len(self.bg.palette_texs)
	self.atlas_l = len(self.bg.tile_atlas_texs)
	background.texture = self.bg.tilemap_tex
	background.material.set_shader_param('palette', self.bg.palette_texs[0])
	background.material.set_shader_param('tile_atlas', self.bg.tile_atlas_texs[0])

# Called every frame. 'delta' is the elapsed time since the previous frame.
var t := 0.0
func _process(delta: float) -> void:
	if not self.bg:
		return
	self.t = fmod(self.t + delta, 30.0)
	background.material.set_shader_param('palette', self.bg.palette_texs[int(self.t * 30) % self.pal_l])
	background.material.set_shader_param('tile_atlas', self.bg.tile_atlas_texs[int(self.t * 7.5) % self.atlas_l])