class_name GenerationFeature extends Node3D
## Base class for world features generated during worldgen.
##
## Layers contain features. Some features may contain layers.

@export var noise_scale := Vector3.ONE
@export var noise_offset := Vector3.ZERO

var sub_layers: Array[GenerationLayer]:
	get():
		if not _defined_sub_layers:
			sub_layers = _find_sub_layers(self)
			_defined_sub_layers = true
		return sub_layers
var _defined_sub_layers := false
var _generated := false


func _find_sub_layers(node: Node) -> Array[GenerationLayer]:
	var layers: Array[GenerationLayer] = []
	if node is GenerationLayer:
		layers.append(node)
	for c: Node in node.get_children():
		# Do not walk outside of this scene
		if c.owner in [owner, self]:
			layers.append_array(_find_sub_layers(c))
	return layers


func probe() -> void:
	# TODO may want to make low-detail & high-detail probes distinct
	if not _generated:
		generate()
		_generated = true

	for layer in sub_layers:
		layer.probe()


## Generate elements of this feature. Called by default on the first call to `probe`
func generate() -> void:
	pass  # Implemented in derived type


func sample_noise() -> float:
	var sample_point := global_position * noise_scale + noise_offset
	return WorldGenManager.noise.get_noise_3dv(sample_point)