add undo feature

Script/Level.gd

@@ -21,19 +21,37 @@ export var stairs_x := 0
 export var stairs_y := 0
 
 var completed := false
-var initial_state
+var saved_steps := []
+
+class StepSnap:
+	var waste := {}
+	var reservoir : int
+	var player_position : Vector2
+	var player_direction : Player.Movement
+	
+	static func snap(var l : Level) -> StepSnap:
+		var step = StepSnap.new()
+		for w in l._waste.get_used_cells():
+			step.waste[w] = l._waste.get_cellv(w)
+		step.reservoir = l._player.reservoir
+		step.player_position = l._player.tile_position
+		step.player_direction = l._player.current_direction
+		return step
+	
+	func restore(var l : Level) -> void:
+		l._waste.clear()
+		for w in self.waste:
+			l._waste.set_cellv(w, self.waste[w])
+		l._player.reservoir = self.reservoir
+		l._player.tile_position = self.player_position
+		l._player.current_direction = self.player_direction
+		
 
 func _ready():
 	_player.level = self
 	_player.tile_position = Vector2(start_x, start_y)
 	_stairs.visible = false
 	_stairs.modulate = Color.white
-	initial_state = {
-		waste = {},
-		reservoir = _player.reservoir
-	}
-	for w in _waste.get_used_cells():
-		initial_state.waste[w] = _waste.get_cellv(w)
 
 func _process(_delta):
 	
@@ -145,6 +163,8 @@ class Tile:
 	func dash(var direction: Vector2, var tile_limit = INF, var waste_limit = INF) -> Tile:
 		var waste_line = get_waste_line(direction, true, tile_limit)
 		waste_line.resize(min(waste_limit, waste_line.size()))
+		if not waste_line.empty():
+			level.take_snap()
 		for tile in waste_line:
 			tile.set_tile(level._waste, -1)
 		level.check_completed()
@@ -184,29 +204,26 @@ func waste_sound(var number :int):
 func player_initial_position():
 	_player.level = self
 	_player.tile_position = Vector2(start_x, start_y)
-	_player.update_position()
 	if not Engine.editor_hint:
 		_player.current_direction = _player.movements.back()
-		_player.update_animation()
 
-func reset():
+func take_snap():
 	if not completed:
+		saved_steps.push_back(StepSnap.snap(self))
+	
+func undo():
+	if not completed and not saved_steps.empty():
+		saved_steps.pop_back().restore(self)
 		
-		_waste.clear()
-		for w in initial_state.waste:
-			_waste.set_cellv(w, initial_state.waste[w])
-		
-		player_initial_position()
-		
-		_player.reservoir = initial_state.reservoir
-		update_reservoir()
+func reset():
+	if not completed and not saved_steps.empty():
+		saved_steps.front().restore(self)
+		saved_steps.clear()
 
 func check_player_stairs():
 	if get_tile_v(_player.tile_position).is_stairs():
 		_player.tile_position = Vector2(stairs_x - 1, stairs_y - 2)
 		_player.current_direction = _player.movements.back()
-		_player.update_position()
-		_player.update_animation()
 
 func end_of_level():
 	_player.visible = false

Script/Player.gd

@@ -12,7 +12,7 @@ var level
 onready var footsteps = $FootSteps
 onready var deny = $Deny
 
-var tile_position := Vector2(0,0)
+var tile_position := Vector2(0,0) setget update_position
 var last_move_time := 0.0
 var step_count := 0
 var stepped := false
@@ -56,7 +56,7 @@ onready var sweeps = [
 
 var movement_queue = []
 var current_target = null
-var current_direction : Movement = movements.back()
+var current_direction : Movement = movements.back() setget update_animation
 onready var sprite = $AnimatedSprite as AnimatedSprite
 
 func _process(delta):
@@ -64,8 +64,11 @@ func _process(delta):
 	if Engine.editor_hint:
 		return 
 
-	if Input.is_action_pressed("reset"):
+	if Input.is_action_just_pressed("reset"):
 		level.reset()
+	
+	if Input.is_action_just_pressed("undo"):
+		level.undo()
 
 	if (last_move_time + rest) * 1000 < OS.get_ticks_msec():
 		for movement in movements:
@@ -75,7 +78,6 @@ func _process(delta):
 					var target = level.get_tile_v(tile_position + movement.direction)
 					if target.can_walk(movement.direction) or target.can_push(movement.direction):
 						movement_queue.push_back(movement)
-						
 				
 	update_animation()
 	
@@ -92,6 +94,7 @@ func _process(delta):
 			else:
 				tile.push(current_movement.direction)
 				footsteps.play()
+				level.take_snap()
 		
 		if current_target != null:
 			tile_position += current_movement.direction * delta * (speed_dash if dashing else speed)
@@ -143,9 +146,13 @@ func _process(delta):
 				deny.play()
 			
 
-func update_position():
+func update_position(var new_pos = false):
+	if new_pos is Vector2:
+		tile_position = new_pos
 	position = level._floor.cell_custom_transform * (tile_position + Vector2.ONE / 2 )
 	
-func update_animation():
+func update_animation(var new_dir = false):
+	if new_dir is Movement:
+		current_direction = new_dir
 	sprite.animation = current_direction.animation
 	sprite.frame = step_count % 2 + (0 if reservoir > 0 else 2)

project.godot

@@ -105,6 +105,11 @@ reset={
 , Object(InputEventJoypadButton,"resource_local_to_scene":false,"resource_name":"","device":0,"button_index":3,"pressure":0.0,"pressed":false,"script":null)
  ]
 }
+undo={
+"deadzone": 0.5,
+"events": [ Object(InputEventKey,"resource_local_to_scene":false,"resource_name":"","device":0,"alt":false,"shift":false,"control":false,"meta":false,"command":false,"pressed":false,"scancode":90,"unicode":0,"echo":false,"script":null)
+ ]
+}
 
 [physics]