Add NavigationServer map_force_update() function

Adds map_force_update() function to NavigationServer. This function immediately flushes the Navigationserver command queue and recalculates all navigationmeshes and region connections for a specific map.

(cherry picked from commit fdea269)

doc/classes/Navigation2DServer.xml

@@ -139,6 +139,16 @@
 				Create a new map.
 			</description>
 		</method>
+		<method name="map_force_update">
+			<return type="void" />
+			<argument index="0" name="map" type="RID" />
+			<description>
+				This function immediately forces synchronization of the specified navigation [code]map[/code] [RID]. By default navigation maps are only synchronized at the end of each physics frame. This function can be used to immediately (re)calculate all the navigation meshes and region connections of the navigation map. This makes it possible to query a navigation path for a changed map immediately and in the same frame (multiple times if needed).
+				Due to technical restrictions the current NavigationServer command queue will be flushed. This means all already queued update commands for this physics frame will be executed, even those intended for other maps, regions and agents not part of the specified map. The expensive computation of the navigation meshes and region connections of a map will only be done for the specified map. Other maps will receive the normal synchronization at the end of the physics frame. Should the specified map receive changes after the forced update it will update again as well when the other maps receive their update.
+				Avoidance processing and dispatch of the [code]safe_velocity[/code] signals is untouched by this function and continues to happen for all maps and agents at the end of the physics frame.
+				[b]Note:[/b] With great power comes great responsibility. This function should only be used by users that really know what they are doing and have a good reason for it. Forcing an immediate update of a navigation map requires locking the NavigationServer and flushing the entire NavigationServer command queue. Not only can this severely impact the performance of a game but it can also introduce bugs if used inappropriately without much foresight.
+			</description>
+		</method>
 		<method name="map_get_agents" qualifiers="const">
 			<return type="Array" />
 			<argument index="0" name="map" type="RID" />

doc/classes/NavigationServer.xml

@@ -138,6 +138,16 @@
 				Create a new map.
 			</description>
 		</method>
+		<method name="map_force_update">
+			<return type="void" />
+			<argument index="0" name="map" type="RID" />
+			<description>
+				This function immediately forces synchronization of the specified navigation [code]map[/code] [RID]. By default navigation maps are only synchronized at the end of each physics frame. This function can be used to immediately (re)calculate all the navigation meshes and region connections of the navigation map. This makes it possible to query a navigation path for a changed map immediately and in the same frame (multiple times if needed).
+				Due to technical restrictions the current NavigationServer command queue will be flushed. This means all already queued update commands for this physics frame will be executed, even those intended for other maps, regions and agents not part of the specified map. The expensive computation of the navigation meshes and region connections of a map will only be done for the specified map. Other maps will receive the normal synchronization at the end of the physics frame. Should the specified map receive changes after the forced update it will update again as well when the other maps receive their update.
+				Avoidance processing and dispatch of the [code]safe_velocity[/code] signals is untouched by this function and continues to happen for all maps and agents at the end of the physics frame.
+				[b]Note:[/b] With great power comes great responsibility. This function should only be used by users that really know what they are doing and have a good reason for it. Forcing an immediate update of a navigation map requires locking the NavigationServer and flushing the entire NavigationServer command queue. Not only can this severely impact the performance of a game but it can also introduce bugs if used inappropriately without much foresight.
+			</description>
+		</method>
 		<method name="map_get_agents" qualifiers="const">
 			<return type="Array" />
 			<argument index="0" name="map" type="RID" />

modules/navigation/godot_navigation_server.cpp

@@ -619,6 +619,15 @@ void GodotNavigationServer::flush_queries() {
 	commands.clear();
 }
 
+void GodotNavigationServer::map_force_update(RID p_map) {
+	NavMap *map = map_owner.getornull(p_map);
+	ERR_FAIL_COND(map == nullptr);
+
+	flush_queries();
+
+	map->sync();
+}
+
 void GodotNavigationServer::process(real_t p_delta_time) {
 	flush_queries();
 

modules/navigation/godot_navigation_server.h

@@ -111,6 +111,8 @@ class GodotNavigationServer : public NavigationServer {
 	virtual Array map_get_regions(RID p_map) const;
 	virtual Array map_get_agents(RID p_map) const;
 
+	virtual void map_force_update(RID p_map);
+
 	virtual RID region_create() const;
 
 	COMMAND_2(region_set_enter_cost, RID, p_region, real_t, p_enter_cost);

servers/navigation_2d_server.cpp

@@ -188,6 +188,7 @@ void Navigation2DServer::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("map_get_regions", "map"), &Navigation2DServer::map_get_regions);
 	ClassDB::bind_method(D_METHOD("map_get_agents", "map"), &Navigation2DServer::map_get_agents);
+	ClassDB::bind_method(D_METHOD("map_force_update", "map"), &Navigation2DServer::map_force_update);
 
 	ClassDB::bind_method(D_METHOD("region_create"), &Navigation2DServer::region_create);
 	ClassDB::bind_method(D_METHOD("region_set_enter_cost", "region", "enter_cost"), &Navigation2DServer::region_set_enter_cost);
@@ -251,6 +252,10 @@ void FORWARD_2_C(map_set_active, RID, p_map, bool, p_active, rid_to_rid, bool_to
 
 bool FORWARD_1_C(map_is_active, RID, p_map, rid_to_rid);
 
+void Navigation2DServer::map_force_update(RID p_map) {
+	NavigationServer::get_singleton_mut()->map_force_update(p_map);
+}
+
 void FORWARD_2_C(map_set_cell_size, RID, p_map, real_t, p_cell_size, rid_to_rid, real_to_real);
 real_t FORWARD_1_C(map_get_cell_size, RID, p_map, rid_to_rid);
 

servers/navigation_2d_server.h

@@ -89,6 +89,8 @@ class Navigation2DServer : public Object {
 	virtual Array map_get_regions(RID p_map) const;
 	virtual Array map_get_agents(RID p_map) const;
 
+	virtual void map_force_update(RID p_map);
+
 	/// Creates a new region.
 	virtual RID region_create() const;
 

servers/navigation_server.cpp

@@ -54,6 +54,7 @@ void NavigationServer::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("map_get_regions", "map"), &NavigationServer::map_get_regions);
 	ClassDB::bind_method(D_METHOD("map_get_agents", "map"), &NavigationServer::map_get_agents);
+	ClassDB::bind_method(D_METHOD("map_force_update", "map"), &NavigationServer::map_force_update);
 
 	ClassDB::bind_method(D_METHOD("region_create"), &NavigationServer::region_create);
 	ClassDB::bind_method(D_METHOD("region_set_enter_cost", "region", "enter_cost"), &NavigationServer::region_set_enter_cost);

servers/navigation_server.h

@@ -102,6 +102,8 @@ class NavigationServer : public Object {
 	virtual Array map_get_regions(RID p_map) const = 0;
 	virtual Array map_get_agents(RID p_map) const = 0;
 
+	virtual void map_force_update(RID p_map) = 0;
+
 	/// Creates a new region.
 	virtual RID region_create() const = 0;