Adds input buffering to allow you to queue a turn after a turn

Scripts/snake_part.gd

@@ -11,6 +11,8 @@ var state : States = States.ALIVE
 var colour_index : int = 0
 var current_direction : Vector2 = Vector2.RIGHT
 var old_direction : Vector2 = Vector2.RIGHT
+var buffered_direction : Vector2 = Vector2.ZERO
+var should_buffer_direction : bool = false
 
 var inputs : Dictionary[String, Vector2] = {"right": Vector2.RIGHT,
 											"left": Vector2.LEFT,
@@ -199,6 +201,12 @@ func process_movement(new_direction : Vector2, prevent_movment : bool = false) -
 	
 	# Update the sprite
 	update_sprite()
+	
+	if buffered_direction != Vector2.ZERO:
+		current_direction = buffered_direction
+		buffered_direction = Vector2.ZERO
+	else:
+		should_buffer_direction = false
 
 func update_sprite() -> void:
 	
@@ -399,7 +407,11 @@ func _unhandled_input(event: InputEvent) -> void:
 	if event is InputEventKey and part_type == PartTypes.HEAD:
 		for dir in inputs.keys():
 			if event.is_action_pressed(dir) and current_direction != -inputs[dir]:
-				current_direction = inputs[dir]
+				if should_buffer_direction:
+					buffered_direction = inputs[dir]
+				else:
+					current_direction = inputs[dir]
+					should_buffer_direction = true
 
 
 # If we leave the arena