@icon("uid://cbqveb0y8fkiv")
extends MeshInstance3D
class_name Ocean

var material: ShaderMaterial
var noise: Image

var noise_scale: float
var wave_speed: float
var height_scale: float

var time: float

# Called when the node enters the scene tree for the first time.
func _ready():
	add_to_group("ocean",true)
	material = mesh.surface_get_material(0)
	update()
	
	# Called every frame. 'delta' is the elapsed time since the previous frame.
func _process(delta):
	time += delta
	material.set_shader_parameter("wave_time", time)

func get_water_level(world_position: Vector3) -> float:
	var uv_x = wrapf(world_position.x / noise_scale + time * wave_speed, 0, 1)
	var uv_y = wrapf(world_position.z / noise_scale + time * wave_speed, 0, 1)

	var pixel_pos = Vector2(uv_x * noise.get_width(), uv_y * noise.get_height())
	return global_position.y + noise.get_pixelv(pixel_pos).r * height_scale;
	
func update():
	if material != null:
		noise = material.get_shader_parameter("wave").noise.get_seamless_image(512, 512)
		noise_scale = material.get_shader_parameter("noise_scale")
		wave_speed = material.get_shader_parameter("wave_speed")
		height_scale = material.get_shader_parameter("height_scale")