center pieces inside taquin

game/src/Taquin.gd

@@ -13,7 +13,8 @@ export var height: int = 512
 export var difficulty: int = 10
 
 var interpiece: int = 4
-var padding = 15
+var min_padding = 15
+var padding = Vector2(min_padding, min_padding)
 
 var pieces: Array = []
 var missing_piece: Vector2
@@ -24,8 +25,19 @@ var current_animation_path: String = "AnimationPlayer/MockPiece:position"
 var swipe = Vector2(0, 0)
 
 func position_for_index(index: Vector2, size: int) -> Vector2:
-	return Vector2(padding + index.x * (size + interpiece), padding + index.y * (size + interpiece))
-	
+	return padding + Vector2(index.x * (size + interpiece), index.y * (size + interpiece))
+
+func compute_piece_size() -> int:
+	var w_size: int = (width - (2 * min_padding) - ((columns - 1) * interpiece)) / columns
+	var h_size: int = (height - (2 * min_padding) - ((rows - 1) * interpiece)) / rows
+	return int(min(w_size, h_size))
+
+func compute_padding(piece_size: int) -> Vector2:
+	var padding = Vector2(0, 0)
+	padding.x = width - columns * piece_size - (columns - 1) * interpiece
+	padding.y = height - rows * piece_size - (rows - 1) * interpiece
+	padding = padding / Vector2(2, 2)
+	return padding
 
 func _ready() -> void:
 	$AnimationPlayer/MockPiece.visible = false
@@ -35,6 +47,9 @@ func _ready() -> void:
 	
 	rng.randomize()
 	var piece_size: int = compute_piece_size()
+	padding = compute_padding(piece_size)
+	print("piece size: ", piece_size)
+	print("padding: ", padding)
 
 	for c in range(columns):
 		var pieces_row: Array = []
@@ -59,11 +74,6 @@ func _ready() -> void:
 
 	shuffle(difficulty)
 
-func compute_piece_size() -> int:
-	var w_size: int = (width - (2 * padding) - ((columns - 1) * interpiece)) / columns
-	var h_size: int = (height - (2 * padding) - ((rows - 1) * interpiece)) / rows
-	return int(min(w_size, h_size))
-
 func _input(event):
 	if $AnimationPlayer.is_playing():
 		# Disable input during animation

game/src/Taquin.tscn

@@ -23,8 +23,8 @@ tracks/0/keys = {
 [node name="Taquin" type="Control"]
 rect_min_size = Vector2( 540, 540 )
 script = ExtResource( 1 )
-rows = 3
-columns = 3
+rows = 5
+columns = 5
 difficulty = 0
 
 [node name="Background" type="ColorRect" parent="."]