extends Node3D
const CENTER := Vector3.ZERO
@export var threshold: float = 0.5

var generate_mesh_shader = preload("res://SurfaceNetsWorld/generate_mesh.tres")

@export var regenerate_mesh = false


@export var chunk_size = 16
@export var show_sample_points = false
@export var show_surface_points = false
@export var show_surface = true

var mesh

var color = Color.RED

var meshinstance = MeshInstance3D.new()
var material = ShaderMaterial.new()

var gpu_sdf

func generate_chunk(pgpu_sdf) -> void:
	gpu_sdf = pgpu_sdf
	material.shader = generate_mesh_shader
	meshinstance.material_override = material
	add_child(meshinstance)
	meshinstance.mesh = gpu_sdf.compute_mesh(chunk_size, threshold, self.position)
	
func _input(event):
	if event is InputEventKey and event.is_action_released("RegenerateMesh"):
		if regenerate_mesh:
			regenerate_mesh = false
		else:
			regenerate_mesh = true

func _process(_delta: float) -> void:
	if show_surface && regenerate_mesh:
		regenerate_mesh = false
		clear()
		meshinstance.mesh = gpu_sdf.compute_mesh(chunk_size, threshold, self.position)
	if show_surface_points:
		var idx = 0
		var text_id = 0
		while idx < gpu_sdf.iout_surface_points.size()/ 2:
			text_id += 1
			var value = Vector3(gpu_sdf.iout_surface_points.get(idx), gpu_sdf.iout_surface_points.get(idx+1), gpu_sdf.iout_surface_points.get(idx+2)) - Vector3(chunk_size / 2, chunk_size / 2, chunk_size / 2)
			if gpu_sdf.iout_surface_points.get(idx) != -1.0:
				DebugDraw3D.draw_square(value, 0.2, color.from_rgba8(255, 128, 128, 255))
				if text_id % 1 == 0:
					DebugDraw3D.draw_text(value, str(value), 35)
				idx += 3
			else:
				idx += 1
	

func clear():
	mesh = ArrayMesh.new()


func get_index_from_coords(coords: Vector3i):
	return coords.x + coords.y * chunk_size + coords.z * chunk_size * chunk_size