godot, bob, rotate, up and down, back and fourth

coin.gd

extends Area2D

var rotate_speed : float = 3.0
var bob_height: float = 5.0
var bob_speed: float = 5.0

@onready var start_position: Vector2 =  global_position
@onready var sprite = $Sprite2D

func _physics_process(delta: float) -> void:
	var time = Time.get_unix_time_from_system()
	#rotate
	sprite.scale.x = sin(time * rotate_speed)
	
	#bob up and down
	var y_pos 	= ((1+sin(time * bob_speed)) / 2) * bob_height
	global_position.y = start_position.y - y_pos