@tool
extends Node3D
class_name CrowdMarker
## A designer-placed spot for one billboard spectator. Drop these into a level in the
## editor; crowd_billboards.gd harvests every marker (via the &"crowd_marker" group) into
## its MultiMesh at runtime, using each marker's global position and chosen facing.
##
## The marker draws a lightweight preview (a slab standing in for the sprite + a forward
## arrow) so its position and orientation are visible in the viewport. That preview is
## editor-only and never serialised into the scene, so it costs nothing at runtime.

## The six selectable facings, one every 60° about the Y axis. DEG_0 faces the quad's
## front (+Z) along world +Z; increasing values rotate clockwise looking down.
enum Orientation {
	DEG_0,
	DEG_60,
	DEG_120,
	DEG_180,
	DEG_240,
	DEG_300,
}

const ORIENTATION_STEPS := 6
## Metres — matches crowd_billboards.figure_height so the editor preview reads true to scale.
const PREVIEW_HEIGHT := 2.0

@export var orientation := Orientation.DEG_0:
	set(value):
		orientation = value
		_apply_orientation()

var _preview: Node3D


func _ready() -> void:
	add_to_group(&"crowd_marker")
	if Engine.is_editor_hint():
		_build_preview()
		_apply_orientation()


# Facing about Y for the current orientation: 0, 60, 120 … degrees as radians.
func facing_yaw() -> float:
	return float(orientation) * (TAU / float(ORIENTATION_STEPS))


# Unit forward the spectator's front (+Z) points along, on the horizontal plane.
func facing_dir() -> Vector3:
	var a := facing_yaw()
	return Vector3(sin(a), 0.0, cos(a))


func _apply_orientation() -> void:
	if _preview != null:
		_preview.rotation = Vector3(0.0, facing_yaw(), 0.0)


# Editor-only preview. Children are added without an owner so they are excluded from the
# saved .tscn (Godot only serialises nodes owned by the scene root).
func _build_preview() -> void:
	_preview = Node3D.new()
	add_child(_preview)

	var aspect := 0.5
	var slab := MeshInstance3D.new()
	var quad := QuadMesh.new()
	quad.size = Vector2(PREVIEW_HEIGHT * aspect, PREVIEW_HEIGHT)
	quad.center_offset = Vector3(0.0, PREVIEW_HEIGHT * 0.5, 0.0)   # stand on the marker
	slab.mesh = quad
	slab.material_override = _preview_material(Color(0.3, 0.7, 1.0, 0.35))
	_preview.add_child(slab)

	var arrow := MeshInstance3D.new()
	var shaft := BoxMesh.new()
	shaft.size = Vector3(0.08, 0.08, PREVIEW_HEIGHT * 0.5)
	arrow.mesh = shaft
	# Push the shaft out along +Z (the facing) and up to chest height.
	arrow.position = Vector3(0.0, PREVIEW_HEIGHT * 0.5, PREVIEW_HEIGHT * 0.25)
	arrow.material_override = _preview_material(Color(1.0, 0.85, 0.2, 0.9))
	_preview.add_child(arrow)


func _preview_material(col: Color) -> StandardMaterial3D:
	var mat := StandardMaterial3D.new()
	mat.albedo_color = col
	mat.shading_mode = BaseMaterial3D.SHADING_MODE_UNSHADED
	mat.transparency = BaseMaterial3D.TRANSPARENCY_ALPHA
	mat.cull_mode = BaseMaterial3D.CULL_DISABLED
	return mat