From 892b993b9e2a3df1137564db645c32b506510f32 Mon Sep 17 00:00:00 2001
From: Emmanouil Papadeas <35376950+OverloadedOrama@users.noreply.github.com>
Date: Wed, 19 Feb 2025 00:10:22 +0200
Subject: [PATCH] Fix tilesets being re-ordered when being moved, resized or
 deleted by selections

---
 src/Classes/Cels/CelTileMap.gd | 11 +++++++----
 src/UI/Canvas/Selection.gd     |  7 ++++++-
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/src/Classes/Cels/CelTileMap.gd b/src/Classes/Cels/CelTileMap.gd
index b03a9a747..0118672aa 100644
--- a/src/Classes/Cels/CelTileMap.gd
+++ b/src/Classes/Cels/CelTileMap.gd
@@ -574,12 +574,15 @@ func update_cel_portions() -> void:
 
 ## Loops through all [member cells] of the tilemap and updates their indices,
 ## so they can remain mapped to the [member tileset]'s tiles.
-func _re_index_all_cells() -> void:
+func re_index_all_cells(set_invisible_to_zero := false) -> void:
 	for i in cells.size():
 		var coords := get_cell_coords_in_image(i)
 		var rect := Rect2i(coords, tileset.tile_size)
 		var image_portion := image.get_region(rect)
 		if image_portion.is_invisible():
+			if set_invisible_to_zero:
+				cells[i].index = 0
+				continue
 			var index := cells[i].index
 			if index > 0 and index < tileset.tiles.size():
 				var current_tile := tileset.tiles[index]
@@ -616,7 +619,7 @@ func _is_redo() -> bool:
 ## If [param replace_index] is larger than -1, it means that manual mode
 ## has been used to replace a tile in the tileset in another cel,
 ## so call [method update_cel_portions] to update it in this cel as well.
-## Otherwise, call [method _re_index_all_cells] to ensure that the cells have correct indices.
+## Otherwise, call [method re_index_all_cells] to ensure that the cells have correct indices.
 func _on_tileset_updated(cel: CelTileMap, replace_index: int) -> void:
 	if cel == self:
 		return
@@ -625,7 +628,7 @@ func _on_tileset_updated(cel: CelTileMap, replace_index: int) -> void:
 	if replace_index > -1:  # Manual mode
 		update_cel_portions()
 	else:
-		_re_index_all_cells()
+		re_index_all_cells()
 	Global.canvas.update_all_layers = true
 	Global.canvas.queue_redraw()
 
@@ -642,7 +645,7 @@ func _deserialize_cell_data(cell_indices: Array, resize: bool) -> void:
 func set_content(content, texture: ImageTexture = null) -> void:
 	super.set_content(content, texture)
 	_resize_cells(image.get_size())
-	_re_index_all_cells()
+	re_index_all_cells()
 
 
 func update_texture(undo := false) -> void:
diff --git a/src/UI/Canvas/Selection.gd b/src/UI/Canvas/Selection.gd
index 4fad0d9bf..30688dfa6 100644
--- a/src/UI/Canvas/Selection.gd
+++ b/src/UI/Canvas/Selection.gd
@@ -665,7 +665,12 @@ func commit_undo(action: String, undo_data_tmp: Dictionary) -> void:
 		print("No undo data found!")
 		return
 	var project := Global.current_project
-	project.update_tilemaps(undo_data_tmp, TileSetPanel.TileEditingMode.AUTO)
+	if Tools.is_placing_tiles():
+		for cel in undo_data_tmp:
+			if cel is CelTileMap:
+				(cel as CelTileMap).re_index_all_cells(true)
+	else:
+		project.update_tilemaps(undo_data_tmp, TileSetPanel.TileEditingMode.AUTO)
 	var redo_data := get_undo_data(undo_data_tmp["undo_image"])
 	project.undos += 1
 	project.undo_redo.create_action(action)