extends Object
class_name ReplayRecording

const TAPER: float = 7.0

var time_per_frame: float
var frames: int = 0

var positions: Array
var sprites: Array

func load_from(file: File):
	time_per_frame = file.get_real()
	frames = file.get_32()
	positions = []
	sprites = []
	
	for _i in range(frames):
		var x: float = file.get_real()
		var y: float = file.get_real()
		positions.append(Vector2(x, y))
		sprites.append(file.get_8())

func load_from_uri(uri: String):
	var file: File = File.new()
	file.open(uri, File.READ)
	load_from(file)
	file.close()

func save_to(file: File):
	file.store_real(time_per_frame)
	file.store_32(frames)
	
	for i in range(frames):
		file.store_real(positions[i].x)
		file.store_real(positions[i].y)
		file.store_8(sprites[i])

func save_to_uri(uri: String):
	var file: File = File.new()
	file.open(uri, File.WRITE)
	save_to(file)
	file.close()

func position(frame: int) -> Vector2:
	if frame < frames:
		return positions[frame]
	else:
		return lerp(positions[-2], positions[-1], 2 + TAPER * atan((frame - frames) / TAPER))

func sprite(frame: int) -> int:
	if frame < frames:
		return sprites[frame]
	else:
		return sprites[-1]

func length() -> float:
	return time_per_frame * frames