Make manual tile editing mode automatically update all other image portions that have the same tile index

src/Autoload/Global.gd

@@ -983,7 +983,7 @@ func undo_or_redo(
 			var cel := project.frames[frame_index].cels[layer_index]
 			if action_name == "Scale":
 				cel.size_changed(project.size)
-			canvas.update_texture(layer_index, frame_index, project)
+			canvas.update_texture(layer_index, frame_index, project, undo)
 			cel.on_undo_redo(undo)
 		else:
 			for i in project.frames.size():
@@ -991,7 +991,7 @@ func undo_or_redo(
 					var cel := project.frames[i].cels[j]
 					if action_name == "Scale":
 						cel.size_changed(project.size)
-					canvas.update_texture(j, i, project)
+					canvas.update_texture(j, i, project, undo)
 					cel.on_undo_redo(undo)
 
 		canvas.selection.queue_redraw()

src/Classes/Cels/BaseCel.gd

@@ -67,7 +67,7 @@ func get_image() -> Image:
 
 
 ## Used to update the texture of the cel.
-func update_texture() -> void:
+func update_texture(_undo := false) -> void:
 	texture_changed.emit()
 	if link_set != null:
 		var frame := Global.current_project.current_frame

src/Classes/Cels/CelTileMap.gd

@@ -14,6 +14,12 @@ var indices_y: int
 ## Dictionary of [int] and an [Array] of [bool] ([member TileSetPanel.placing_tiles])
 ## and [enum TileSetPanel.TileEditingMode].
 var undo_redo_modes := {}
+## Dictionary of [int] and [Array].
+## The key is the index of the tile in the tileset,
+## and the value is the index of the tilemap tile that changed first, along with
+## its image that is being changed when manual mode is enabled.
+## Gets reset on [method update_tileset].
+var editing_images := {}
 
 
 func _init(_tileset: TileSetCustom, _image: ImageExtended, _opacity := 1.0) -> void:
@@ -30,6 +36,7 @@ func set_index(tile_position: int, index: int) -> void:
 
 
 func update_tileset(undo: bool) -> void:
+	editing_images.clear()
 	var undos := tileset.project.undos
 	if not undo and not _is_redo():
 		undo_redo_modes[undos] = [TileSetPanel.placing_tiles, TileSetPanel.tile_editing_mode]
@@ -42,7 +49,7 @@ func update_tileset(undo: bool) -> void:
 		var image_portion := image.get_region(rect)
 		var index := indices[i]
 		if index >= tileset.tiles.size():
-			print(i, " is out of bounds")
+			printerr("Tile at position ", i, ", mapped to ", index, " is out of bounds!")
 			index = 0
 			indices[i] = 0
 		var current_tile := tileset.tiles[index]
@@ -57,7 +64,6 @@ func update_tileset(undo: bool) -> void:
 				continue
 			if image_portion.get_data() != current_tile.image.get_data():
 				tileset.replace_tile_at(image_portion, index)
-				update_cel_portions()
 		elif tile_editing_mode == TileSetPanel.TileEditingMode.AUTO:
 			handle_auto_editing_mode(i, image_portion)
 		else:  # Stack
@@ -195,6 +201,7 @@ func update_cel_portion(tile_position: int) -> void:
 		image.blit_rect(current_tile.image, Rect2i(Vector2i.ZERO, tile_size), coords)
 
 
+## Unused, should delete.
 func update_cel_portions() -> void:
 	for i in indices.size():
 		update_cel_portion(i)
@@ -247,21 +254,35 @@ func _get_tile_editing_mode(undos: int) -> TileSetPanel.TileEditingMode:
 
 
 # Overridden Methods:
-func update_texture() -> void:
-	var undos := tileset.project.undos
-	#if undo:
-	#undos += 1
-	var tile_editing_mode := _get_tile_editing_mode(undos)
-	if tile_editing_mode == TileSetPanel.TileEditingMode.MANUAL:
+func update_texture(undo := false) -> void:
+	var tile_editing_mode := TileSetPanel.tile_editing_mode
+	if undo or _is_redo() or tile_editing_mode != TileSetPanel.TileEditingMode.MANUAL:
+		super.update_texture(undo)
+		return
+
 	for i in indices.size():
 		var index := indices[i]
-			# Prevent from drawing on empty image portions.
-			if index == 0 and tileset.tiles.size() > 1:
 		var coords := get_tile_coords(i)
+		var rect := Rect2i(coords, tileset.tile_size)
+		var image_portion := image.get_region(rect)
 		var current_tile := tileset.tiles[index]
+		if index == 0 and tileset.tiles.size() > 1:
+			# Prevent from drawing on empty image portions.
 			var tile_size := current_tile.image.get_size()
 			image.blit_rect(current_tile.image, Rect2i(Vector2i.ZERO, tile_size), coords)
-	super.update_texture()
+			continue
+		if editing_images.has(index):
+			var editing_portion := editing_images[index][0] as int
+			if i == editing_portion:
+				editing_images[index] = [i, image_portion]
+			var editing_image := editing_images[index][1] as Image
+			if editing_image.get_data() != image_portion.get_data():
+				var tile_size := image_portion.get_size()
+				image.blit_rect(editing_image, Rect2i(Vector2i.ZERO, tile_size), coords)
+		else:
+			if image_portion.get_data() != current_tile.image.get_data():
+				editing_images[index] = [i, image_portion]
+	super.update_texture(undo)
 
 
 func size_changed(new_size: Vector2i) -> void:

src/Classes/Cels/PixelCel.gd

@@ -54,9 +54,9 @@ func get_image() -> ImageExtended:
 	return image
 
 
-func update_texture() -> void:
+func update_texture(undo := false) -> void:
 	image_texture.set_image(image)
-	super.update_texture()
+	super.update_texture(undo)
 
 
 func get_class_name() -> String:

src/UI/Canvas/Canvas.gd

@@ -110,13 +110,15 @@ func camera_zoom() -> void:
 	Global.transparent_checker.update_rect()
 
 
-func update_texture(layer_i: int, frame_i := -1, project := Global.current_project) -> void:
+func update_texture(
+	layer_i: int, frame_i := -1, project := Global.current_project, undo := false
+) -> void:
 	if frame_i == -1:
 		frame_i = project.current_frame
 
 	if frame_i < project.frames.size() and layer_i < project.layers.size():
 		var current_cel := project.frames[frame_i].cels[layer_i]
-		current_cel.update_texture()
+		current_cel.update_texture(undo)
 		# Needed so that changes happening to the non-selected layer(s) are also visible
 		# e.g. when undoing/redoing, when applying image effects to the entire frame, etc
 		if frame_i != project.current_frame: