Fix navigation support for multilayered TileMaps

Fixes support for multilayered TileMaps by creating dedicated navigation maps for each layer.

3 files changed, 82 insertions, 1 deletions

diff --git a/doc/classes/TileMap.xml b/doc/classes/TileMap.xml
index 5dedea50d0..0d2368691f 100644
--- a/doc/classes/TileMap.xml
+++ b/doc/classes/TileMap.xml
@@ -168,6 +168,15 @@
 				Returns the number of layers in the TileMap.
 			</description>
 		</method>
+		<method name="get_navigation_map" qualifiers="const">
+			<return type="RID" />
+			<param index="0" name="layer" type="int" />
+			<description>
+				Returns the [NavigationServer2D] navigation map [RID] currently assigned to the specified TileMap [param layer].
+				By default the TileMap uses the default [World2D] navigation map for the first TileMap layer. For each additional TileMap layer a new navigation map is created for the additional layer.
+				In order to make [NavigationAgent2D] switch between TileMap layer navigation maps use [method NavigationAgent2D.set_navigation_map] with the navigation map received from [method get_navigation_map].
+			</description>
+		</method>
 		<method name="get_neighbor_cell" qualifiers="const">
 			<return type="Vector2i" />
 			<param index="0" name="coords" type="Vector2i" />
@@ -366,6 +375,16 @@
 				If [code]layer[/code] is negative, the layers are accessed from the last one.
 			</description>
 		</method>
+		<method name="set_navigation_map">
+			<return type="void" />
+			<param index="0" name="layer" type="int" />
+			<param index="1" name="map" type="RID" />
+			<description>
+				Assigns a [NavigationServer2D] navigation map [RID] to the specified TileMap [param layer].
+				By default the TileMap uses the default [World2D] navigation map for the first TileMap layer. For each additional TileMap layer a new navigation map is created for the additional layer.
+				In order to make [NavigationAgent2D] switch between TileMap layer navigation maps use [method NavigationAgent2D.set_navigation_map] with the navigation map received from [method get_navigation_map].
+			</description>
+		</method>
 		<method name="set_pattern">
 			<return type="void" />
 			<param index="0" name="layer" type="int" />
diff --git a/scene/2d/tile_map.cpp b/scene/2d/tile_map.cpp
index 95bf67d38d..6eff67aaee 100644
--- a/scene/2d/tile_map.cpp
+++ b/scene/2d/tile_map.cpp
@@ -752,6 +752,20 @@ TileMap::VisibilityMode TileMap::get_navigation_visibility_mode() {
 	return navigation_visibility_mode;
 }
 
+void TileMap::set_navigation_map(int p_layer, RID p_map) {
+	ERR_FAIL_INDEX(p_layer, (int)layers.size());
+
+	layers[p_layer].navigation_map = p_map;
+}
+
+RID TileMap::get_navigation_map(int p_layer) const {
+	ERR_FAIL_INDEX_V(p_layer, (int)layers.size(), RID());
+	if (layers[p_layer].navigation_map.is_valid()) {
+		return layers[p_layer].navigation_map;
+	}
+	return RID();
+}
+
 void TileMap::set_y_sort_enabled(bool p_enable) {
 	Node2D::set_y_sort_enabled(p_enable);
 	_clear_internals();
@@ -897,6 +911,9 @@ void TileMap::_recreate_layer_internals(int p_layer) {
 	// Update the layer internals.
 	_rendering_update_layer(p_layer);
 
+	// Update the layer internal navigation maps.
+	_navigation_update_layer(p_layer);
+
 	// Recreate the quadrants.
 	const HashMap<Vector2i, TileMapCell> &tile_map = layers[p_layer].tile_map;
 	for (const KeyValue<Vector2i, TileMapCell> &E : tile_map) {
@@ -959,6 +976,9 @@ void TileMap::_clear_layer_internals(int p_layer) {
 	// Clear the layers internals.
 	_rendering_cleanup_layer(p_layer);
 
+	// Clear the layers internal navigation maps.
+	_navigation_cleanup_layer(p_layer);
+
 	// Clear the dirty quadrants list.
 	while (layers[p_layer].dirty_quadrant_list.first()) {
 		layers[p_layer].dirty_quadrant_list.remove(layers[p_layer].dirty_quadrant_list.first());
@@ -1083,6 +1103,36 @@ void TileMap::_rendering_notification(int p_what) {
 	}
 }
 
+void TileMap::_navigation_update_layer(int p_layer) {
+	ERR_FAIL_INDEX(p_layer, (int)layers.size());
+	ERR_FAIL_NULL(NavigationServer2D::get_singleton());
+
+	if (!layers[p_layer].navigation_map.is_valid()) {
+		if (p_layer == 0 && is_inside_tree()) {
+			// Use the default World2D navigation map for the first layer when empty.
+			layers[p_layer].navigation_map = get_world_2d()->get_navigation_map();
+		} else {
+			RID new_layer_map = NavigationServer2D::get_singleton()->map_create();
+			NavigationServer2D::get_singleton()->map_set_active(new_layer_map, true);
+			layers[p_layer].navigation_map = new_layer_map;
+		}
+	}
+}
+
+void TileMap::_navigation_cleanup_layer(int p_layer) {
+	ERR_FAIL_INDEX(p_layer, (int)layers.size());
+	ERR_FAIL_NULL(NavigationServer2D::get_singleton());
+
+	if (layers[p_layer].navigation_map.is_valid()) {
+		if (is_inside_tree() && layers[p_layer].navigation_map == get_world_2d()->get_navigation_map()) {
+			// Do not delete the World2D default navigation map.
+			return;
+		}
+		NavigationServer2D::get_singleton()->free(layers[p_layer].navigation_map);
+		layers[p_layer].navigation_map = RID();
+	}
+}
+
 void TileMap::_rendering_update_layer(int p_layer) {
 	ERR_FAIL_INDEX(p_layer, (int)layers.size());
 
@@ -1732,6 +1782,9 @@ void TileMap::_navigation_update_dirty_quadrants(SelfList<TileMapQuadrant>::List
 					q.navigation_regions[E_cell].resize(tile_set->get_navigation_layers_count());
 
 					for (int layer_index = 0; layer_index < tile_set->get_navigation_layers_count(); layer_index++) {
+						if (layer_index >= (int)layers.size() || !layers[layer_index].navigation_map.is_valid()) {
+							continue;
+						}
 						Ref<NavigationPolygon> navigation_polygon;
 						navigation_polygon = tile_data->get_navigation_polygon(layer_index);
 
@@ -1741,7 +1794,7 @@ void TileMap::_navigation_update_dirty_quadrants(SelfList<TileMapQuadrant>::List
 
 							RID region = NavigationServer2D::get_singleton()->region_create();
 							NavigationServer2D::get_singleton()->region_set_owner_id(region, get_instance_id());
-							NavigationServer2D::get_singleton()->region_set_map(region, get_world_2d()->get_navigation_map());
+							NavigationServer2D::get_singleton()->region_set_map(region, layers[layer_index].navigation_map);
 							NavigationServer2D::get_singleton()->region_set_transform(region, tilemap_xform * tile_transform);
 							NavigationServer2D::get_singleton()->region_set_navigation_layers(region, tile_set->get_navigation_layer_layers(layer_index));
 							NavigationServer2D::get_singleton()->region_set_navigation_polygon(region, navigation_polygon);
@@ -4031,6 +4084,9 @@ void TileMap::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_navigation_visibility_mode", "navigation_visibility_mode"), &TileMap::set_navigation_visibility_mode);
 	ClassDB::bind_method(D_METHOD("get_navigation_visibility_mode"), &TileMap::get_navigation_visibility_mode);
 
+	ClassDB::bind_method(D_METHOD("set_navigation_map", "layer", "map"), &TileMap::set_navigation_map);
+	ClassDB::bind_method(D_METHOD("get_navigation_map", "layer"), &TileMap::get_navigation_map);
+
 	ClassDB::bind_method(D_METHOD("set_cell", "layer", "coords", "source_id", "atlas_coords", "alternative_tile"), &TileMap::set_cell, DEFVAL(TileSet::INVALID_SOURCE), DEFVAL(TileSetSource::INVALID_ATLAS_COORDS), DEFVAL(0));
 	ClassDB::bind_method(D_METHOD("erase_cell", "layer", "coords"), &TileMap::erase_cell);
 	ClassDB::bind_method(D_METHOD("get_cell_source_id", "layer", "coords", "use_proxies"), &TileMap::get_cell_source_id, DEFVAL(false));
diff --git a/scene/2d/tile_map.h b/scene/2d/tile_map.h
index 7cf2a2eded..62d7612be2 100644
--- a/scene/2d/tile_map.h
+++ b/scene/2d/tile_map.h
@@ -211,6 +211,7 @@ private:
 		HashMap<Vector2i, TileMapCell> tile_map;
 		HashMap<Vector2i, TileMapQuadrant> quadrant_map;
 		SelfList<TileMapQuadrant>::List dirty_quadrant_list;
+		RID navigation_map;
 	};
 	LocalVector<TileMapLayer> layers;
 	int selected_layer = -1;
@@ -259,6 +260,8 @@ private:
 	void _physics_draw_quadrant_debug(TileMapQuadrant *p_quadrant);
 
 	void _navigation_notification(int p_what);
+	void _navigation_update_layer(int p_layer);
+	void _navigation_cleanup_layer(int p_layer);
 	void _navigation_update_dirty_quadrants(SelfList<TileMapQuadrant>::List &r_dirty_quadrant_list);
 	void _navigation_cleanup_quadrant(TileMapQuadrant *p_quadrant);
 	void _navigation_draw_quadrant_debug(TileMapQuadrant *p_quadrant);
@@ -339,6 +342,9 @@ public:
 	void set_navigation_visibility_mode(VisibilityMode p_show_navigation);
 	VisibilityMode get_navigation_visibility_mode();
 
+	void set_navigation_map(int p_layer, RID p_map);
+	RID get_navigation_map(int p_layer) const;
+
 	// Cells accessors.
 	void set_cell(int p_layer, const Vector2i &p_coords, int p_source_id = TileSet::INVALID_SOURCE, const Vector2i p_atlas_coords = TileSetSource::INVALID_ATLAS_COORDS, int p_alternative_tile = 0);
 	void erase_cell(int p_layer, const Vector2i &p_coords);