Fix debug rendering in TileMapLayer

scene/2d/tile_map_layer.cpp

@@ -113,8 +113,7 @@ void TileMapLayer::_debug_update(bool p_force_cleanup) {
 		}
 	}
 
-	// Update those quadrants.
-	bool needs_set_not_interpolated = is_inside_tree() && get_tree()->is_physics_interpolation_enabled() && !is_physics_interpolated();
+	// Create new quadrants if needed.
 	for (const Vector2i &quadrant_coords : quadrants_to_updates) {
 		if (!debug_quadrant_map.has(quadrant_coords)) {
 			// Create a new quadrant and add it to the quadrant map.
@@ -123,7 +122,30 @@ void TileMapLayer::_debug_update(bool p_force_cleanup) {
 			new_quadrant->quadrant_coords = quadrant_coords;
 			debug_quadrant_map[quadrant_coords] = new_quadrant;
 		}
+	}
+
+	// Second pass on modified cells to update the list of cells per quandrant.
+	if (_debug_was_cleaned_up || anything_changed) {
+		for (KeyValue<Vector2i, CellData> &kv : tile_map_layer_data) {
+			CellData &cell_data = kv.value;
+			Ref<DebugQuadrant> debug_quadrant = debug_quadrant_map[_coords_to_quadrant_coords(cell_data.coords, TILE_MAP_DEBUG_QUADRANT_SIZE)];
+			if (!cell_data.debug_quadrant_list_element.in_list()) {
+				debug_quadrant->cells.add(&cell_data.debug_quadrant_list_element);
+			}
+		}
+	} else {
+		for (SelfList<CellData> *cell_data_list_element = dirty.cell_list.first(); cell_data_list_element; cell_data_list_element = cell_data_list_element->next()) {
+			CellData &cell_data = *cell_data_list_element->self();
+			Ref<DebugQuadrant> debug_quadrant = debug_quadrant_map[_coords_to_quadrant_coords(cell_data.coords, TILE_MAP_DEBUG_QUADRANT_SIZE)];
+			if (!cell_data.debug_quadrant_list_element.in_list()) {
+				debug_quadrant->cells.add(&cell_data.debug_quadrant_list_element);
+			}
+		}
+	}
 
+	// Update those quadrants.
+	bool needs_set_not_interpolated = is_inside_tree() && get_tree()->is_physics_interpolation_enabled() && !is_physics_interpolated();
+	for (const Vector2i &quadrant_coords : quadrants_to_updates) {
 		Ref<DebugQuadrant> debug_quadrant = debug_quadrant_map[quadrant_coords];
 
 		// Update the quadrant's canvas item.

scene/2d/tile_map_layer.h

@@ -105,6 +105,9 @@ struct CellData {
 	Vector2i coords;
 	TileMapCell cell;
 
+	// Debug
+	SelfList<CellData> debug_quadrant_list_element;
+
 	// Rendering.
 	Ref<RenderingQuadrant> rendering_quadrant;
 	SelfList<CellData> rendering_quadrant_list_element;
@@ -143,6 +146,7 @@ struct CellData {
 	}
 
 	CellData(const CellData &p_other) :
+			debug_quadrant_list_element(this),
 			rendering_quadrant_list_element(this),
 #ifndef PHYSICS_2D_DISABLED
 			physics_quadrant_list_element(this),
@@ -157,6 +161,7 @@ struct CellData {
 	}
 
 	CellData() :
+			debug_quadrant_list_element(this),
 			rendering_quadrant_list_element(this),
 #ifndef PHYSICS_2D_DISABLED
 			physics_quadrant_list_element(this),