check internal state in _input()

src/GameState.gd

@@ -19,6 +19,8 @@ func current_state_name() -> String:
 	return State.keys()[current_state]
 
 func transition_to(state):
+	if current_state == state:
+		return
 	assert(state in transitions[current_state])
 	var previous_state = current_state
 	current_state = state

src/Taquin.gd

@@ -87,6 +87,13 @@ func _ready() -> void:
 	shuffle(difficulty)
 
 func _process(delta):
+	pass
+
+func _input(event):
+	if $AnimationPlayer.is_playing():
+		# Disable input during animation
+		return
+
 	var game_state = get_node_or_null("/root/Main/GameState") as GameState
 	if game_state != null:
 		match game_state.current_state:
@@ -97,11 +104,6 @@ func _process(delta):
 			GameState.State.GAME_OVER:
 				return
 
-func _input(event):
-	if $AnimationPlayer.is_playing():
-		# Disable input during animation
-		return
-
 	#
 	# Handle keyboard input
 	#