Now more than one Navigation Server can be registered.

modules/navigation/register_types.cpp

@@ -52,7 +52,8 @@ NavigationServer *new_server() {
 
 void register_navigation_types(ModuleRegistrationLevel p_level) {
 	if (p_level == MODULE_REGISTRATION_LEVEL_SINGLETON) {
-		NavigationServerManager::set_default_server(new_server);
+		NavigationServerManager::register_server("PandemoniumNavigation", new_server);
+		NavigationServerManager::set_default_server("PandemoniumNavigation");
 
 #ifndef _3D_DISABLED
 		_nav_mesh_generator = memnew(NavigationMeshGenerator);

servers/navigation_server.cpp

@@ -30,6 +30,7 @@
 
 #include "navigation_server.h"
 
+#include "core/config/project_settings.h"
 #include "scene/3d/navigation_mesh_instance.h"
 #include "scene/resources/navigation_mesh.h"
 
@@ -118,13 +119,63 @@ NavigationServer::~NavigationServer() {
 	singleton = nullptr;
 }
 
-NavigationServerCallback NavigationServerManager::create_callback = nullptr;
+Vector<NavigationServerManager::ClassInfo> NavigationServerManager::navigation_servers;
+int NavigationServerManager::default_server_id = -1;
+int NavigationServerManager::default_server_priority = -1;
+const String NavigationServerManager::setting_property_name("navigation/3d/navigation_engine");
 
-void NavigationServerManager::set_default_server(NavigationServerCallback p_callback) {
-	create_callback = p_callback;
+void NavigationServerManager::on_servers_changed() {
+	String navigation_servers2("DEFAULT");
+	for (int i = get_servers_count() - 1; 0 <= i; --i) {
+		navigation_servers2 += "," + get_server_name(i);
+	}
+	ProjectSettings::get_singleton()->set_custom_property_info(setting_property_name, PropertyInfo(Variant::STRING, setting_property_name, PROPERTY_HINT_ENUM, navigation_servers2));
+}
+
+void NavigationServerManager::register_server(const String &p_name, CreateNavigationServerCallback p_creat_callback) {
+	ERR_FAIL_COND(!p_creat_callback);
+	ERR_FAIL_COND(find_server_id(p_name) != -1);
+	navigation_servers.push_back(ClassInfo(p_name, p_creat_callback));
+	on_servers_changed();
+}
+
+void NavigationServerManager::set_default_server(const String &p_name, int p_priority) {
+	const int id = find_server_id(p_name);
+	ERR_FAIL_COND(id == -1); // Not found
+	if (default_server_priority < p_priority) {
+		default_server_id = id;
+		default_server_priority = p_priority;
+	}
+}
+
+int NavigationServerManager::find_server_id(const String &p_name) {
+	for (int i = navigation_servers.size() - 1; 0 <= i; --i) {
+		if (p_name == navigation_servers[i].name) {
+			return i;
+		}
+	}
+	return -1;
+}
+
+int NavigationServerManager::get_servers_count() {
+	return navigation_servers.size();
+}
+
+String NavigationServerManager::get_server_name(int p_id) {
+	ERR_FAIL_INDEX_V(p_id, get_servers_count(), "");
+	return navigation_servers[p_id].name;
 }
 
 NavigationServer *NavigationServerManager::new_default_server() {
-	ERR_FAIL_COND_V(create_callback == nullptr, nullptr);
-	return create_callback();
+	ERR_FAIL_COND_V(default_server_id == -1, nullptr);
+	return navigation_servers[default_server_id].create_callback();
 }
+
+NavigationServer *NavigationServerManager::new_server(const String &p_name) {
+	int id = find_server_id(p_name);
+	if (id == -1) {
+		return nullptr;
+	} else {
+		return navigation_servers[id].create_callback();
+	}
+}

servers/navigation_server.h

@@ -30,8 +30,8 @@
 /* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
 /*************************************************************************/
 
-#include "core/object/object.h"
 #include "core/containers/rid.h"
+#include "core/object/object.h"
 
 #include "core/object/reference.h"
 
@@ -217,15 +217,52 @@ public:
 	virtual ~NavigationServer();
 };
 
-typedef NavigationServer *(*NavigationServerCallback)();
+typedef NavigationServer *(*CreateNavigationServerCallback)();
 
 /// Manager used for the server singleton registration
+
 class NavigationServerManager {
-	static NavigationServerCallback create_callback;
+	struct ClassInfo {
+		String name;
+		CreateNavigationServerCallback create_callback;
+
+		ClassInfo() :
+				name(""),
+				create_callback(nullptr) {}
+
+		ClassInfo(String p_name, CreateNavigationServerCallback p_create_callback) :
+				name(p_name),
+				create_callback(p_create_callback) {}
+
+		ClassInfo(const ClassInfo &p_ci) :
+				name(p_ci.name),
+				create_callback(p_ci.create_callback) {}
+
+		ClassInfo operator=(const ClassInfo &p_ci) {
+			name = p_ci.name;
+			create_callback = p_ci.create_callback;
+			return *this;
+		}
+	};
+
+	static Vector<ClassInfo> navigation_servers;
+	static int default_server_id;
+	static int default_server_priority;
 
 public:
-	static void set_default_server(NavigationServerCallback p_callback);
+	static const String setting_property_name;
+
+private:
+	static void on_servers_changed();
+
+public:
+	static void register_server(const String &p_name, CreateNavigationServerCallback p_create_callback);
+	static void set_default_server(const String &p_name, int p_priority = 0);
+	static int find_server_id(const String &p_name);
+	static int get_servers_count();
+	static String get_server_name(int p_id);
 	static NavigationServer *new_default_server();
+	static NavigationServer *new_server(const String &p_name);
 };
 
 #endif

servers/register_server_types.cpp

@@ -190,6 +190,10 @@ void register_server_types() {
 
 	PhysicsServerManager::register_server("PandemoniumPhysics", &_createPandemoniumPhysicsCallback);
 	PhysicsServerManager::set_default_server("PandemoniumPhysics");
+
+	// Navigation 3D
+	GLOBAL_DEF(NavigationServerManager::setting_property_name, "DEFAULT");
+	ProjectSettings::get_singleton()->set_custom_property_info(NavigationServerManager::setting_property_name, PropertyInfo(Variant::STRING, NavigationServerManager::setting_property_name, PROPERTY_HINT_ENUM, "DEFAULT"));
 }
 
 void unregister_server_types() {