class_name Figures
extends Node2D
## The figures of the other players, with their names, drawn by `art`. A new
## position comes over the network about ten times a second; in between,
## each figure glides toward the latest one, stepping and facing the way it
## goes.

## How quickly a figure closes the gap to its latest position, per second.
const GLIDE := 15.0
## Pixels per frame below which a gliding figure counts as standing.
const STANDING := 0.05
## Size and width of the names, in pixels of the playing field. The names
## are drawn at the size they have on screen, so that they stay sharp.
const NAME_SIZE := 8
const NAME_WIDTH := 80.0
const NAME_OUTLINE := Color(0.05, 0.05, 0.06)

var session: GwSession
var art: Art
var _shown: Dictionary[int, Vector2] = {}
var _latest: Dictionary[int, Vector2] = {}
var _facing: Dictionary[int, float] = {}
var _step: Dictionary[int, float] = {}
var _moving: Dictionary[int, bool] = {}


## Moves the figure of `player` toward `position`. A figure that was not
## shown yet appears there at once.
func place(player: int, position: Vector2) -> void:
	if not _shown.has(player):
		_shown[player] = position
	_latest[player] = position
	queue_redraw()


## Removes the figure of `player`.
func forget(player: int) -> void:
	for figures: Dictionary in [_shown, _latest, _facing, _step, _moving]:
		figures.erase(player)
	queue_redraw()


func clear() -> void:
	for figures: Dictionary in [_shown, _latest, _facing, _step, _moving]:
		figures.clear()
	queue_redraw()


## Where the figure of `player` is shown, or Vector2.INF if it is not.
func shown_at(player: int) -> Vector2:
	return _shown.get(player, Vector2.INF)


## 1.0 if the figure of `player` faces right, -1.0 if it faces left.
func facing_of(player: int) -> float:
	return _facing.get(player, 1.0)


func _process(delta: float) -> void:
	if _shown.is_empty():
		return
	var weight := minf(1.0, GLIDE * delta)
	for player in _shown:
		var before := _shown[player]
		_shown[player] = before.lerp(_latest[player], weight)
		var moved := _shown[player] - before
		if absf(moved.x) > STANDING:
			_facing[player] = signf(moved.x)
		_step[player] = _step.get(player, 0.0) + moved.length() * Avatar.STEP_PER_PIXEL
		_moving[player] = moved.length() > STANDING
	queue_redraw()


func _draw() -> void:
	if art == null:
		return
	var font := ThemeDB.fallback_font
	# The camera enlarges the field. Text drawn at its size on screen and then
	# shrunk stays sharp; text drawn small and enlarged would blur.
	var zoom := maxf(1.0, get_global_transform_with_canvas().get_scale().x)
	for player in _shown:
		var at := _shown[player]
		var state := {"player": player, "facing": facing_of(player), "step": _step.get(player, 0.0), "moving": _moving.get(player, false)}
		art.draw(self, Art.FIGURE, Avatar.figure_rect(at), state)
		if session != null:
			var label := Vector2(at.x - NAME_WIDTH / 2.0, Avatar.figure_rect(at).position.y - 2.0)
			var text := session.player_name(player)
			var size := roundi(NAME_SIZE * zoom)
			draw_set_transform(label, 0.0, Vector2.ONE / zoom)
			draw_string_outline(font, Vector2.ZERO, text, HORIZONTAL_ALIGNMENT_CENTER, NAME_WIDTH * zoom, size, maxi(2, roundi(zoom * 1.5)), NAME_OUTLINE)
			draw_string(font, Vector2.ZERO, text, HORIZONTAL_ALIGNMENT_CENTER, NAME_WIDTH * zoom, size)
			draw_set_transform(Vector2.ZERO, 0.0, Vector2.ONE)