feat: GameMode is now a Node rather than Resource

game_mode.cpp

@@ -10,9 +10,6 @@ void GameMode::_bind_methods() {
     GDPROPERTY_HINTED(player_scene, gd::Variant::OBJECT, gd::PROPERTY_HINT_RESOURCE_TYPE, "PackedScene");
 }
 
-void GameMode::_begin() {}
-void GameMode::_end() {}
-
 void GameMode::set_player_scene(gd::Ref<gd::PackedScene> scene) {
     this->player_scene = scene;
 }

game_mode.hpp

@@ -1,24 +1,21 @@
 #ifndef UTILS_GAME_MODE_HPP
 #define UTILS_GAME_MODE_HPP
 
+#include <godot_cpp/classes/node.hpp>
 #include <godot_cpp/classes/packed_scene.hpp>
-#include <godot_cpp/classes/resource.hpp>
 
 namespace gd = godot;
 
 namespace utils {
 /*! Stores session-relevant data.
  *
- * Contains any data that is only needed for the duration of the current session/match. Use GameState instead if you want data to be saved between sessions.
+ * Inheriting classes are intended to keep only data that is relevant for the duration of the current session/match. Use GameState instead if you want data to be saved between sessions.
  * Will be destroyed when a level is loaded that does not match the same game mode class.
  */
-class GameMode : public gd::Resource {
+class GameMode : public gd::Node {
-    GDCLASS(GameMode, gd::Resource);
+    GDCLASS(GameMode, gd::Node);
     static void _bind_methods();
 public:
-    virtual void _begin(); //!< Called when the match begins.
-    virtual void _end(); //!< Called when the match is ending.
-
     void set_player_scene(gd::Ref<gd::PackedScene> scene);
     gd::Ref<gd::PackedScene> get_player_scene() const;
 private:

game_root.cpp

@@ -96,7 +96,7 @@ bool GameRoot3D::initialize_player(IPlayer *player, uint32_t id) {
 }
 
 void GameRoot3D::reset_game_mode() {
-    this->set_game_mode(gd::Ref<GameMode>());
+    this->set_game_mode(nullptr);
 }
 
 Level3D *GameRoot3D::load_level(gd::Ref<gd::PackedScene> level) {
@@ -116,13 +116,15 @@ Level3D *GameRoot3D::load_level_at(gd::Ref<gd::PackedScene> level, gd::Transform
     instance->connect("tree_exited", callable_mp(this, &GameRoot3D::level_unloaded).bind(level->get_path()));
     // store and add to tree at desired transform
     // if this is the first level containing a game mode currently active use it's gamemode as a prototype
-    bool const switch_game_mode{this->game_mode.is_null()};
+    gd::Ref<gd::PackedScene> game_mode_prototype{instance->get_game_mode_prototype()};
+    bool const switch_game_mode{this->game_mode->get_scene_file_path() != game_mode_prototype->get_path()};
     if(switch_game_mode) {
         this->set_game_mode(instance->get_game_mode_prototype());
     }
     this->add_child(instance);
     instance->set_global_transform(at);
-    if(switch_game_mode && this->game_mode.is_valid()) {
+    // set initial player positions if new player were spawned due to game mode switch
+    if(switch_game_mode && this->game_mode != nullptr) {
         for(gd::KeyValue<uint32_t, gd::Pair<PlayerInput *, IPlayer *>> const &kvp : this->players) {
             this->place_player_at_spawnpoint(kvp.value.second);
         }
@@ -172,19 +174,21 @@ void GameRoot3D::player_despawned(uint32_t id) {
     pair.first->clear_listeners();
 }
 
-void GameRoot3D::set_game_mode(gd::Ref<GameMode> prototype) {
+void GameRoot3D::set_game_mode(gd::Ref<gd::PackedScene> prototype) {
     this->remove_all_players();
-    // allow "unsetting" the gamemode by passing an invalid gamemode
+    if(this->game_mode != nullptr)
-    // shorthand for this behaviour is reset_game_mode
+        this->game_mode->queue_free();
-    if(prototype.is_null() || !prototype.is_valid()) {
+    if(prototype.is_null() || !prototype.is_valid())
-        if(!this->game_mode.is_null() && this->game_mode.is_valid())
+        return; // allow "unsetting" the gamemode by passing an invalid gamemode
-            this->game_mode->_end();
+    // Detect passing of valid scene that is an invalid game mode
-        this->game_mode.unref();
+    if(!gd::ClassDB::is_parent_class(prototype->get_state()->get_node_type(0), "GameMode")) {
+        gd::UtilityFunctions::push_error("Attempted to load non-gamemode scene as gamemode");
         return;
     }
-    // shallow clone the game mode prototype ..
+    // instantiate the game mode as a child
-    this->game_mode = prototype->duplicate(false);
+    this->game_mode = Object::cast_to<GameMode>(prototype->instantiate());
-    this->game_mode->_begin();
+    this->add_child(game_mode);
+    // instantiate players
     if(this->game_mode->get_player_scene().is_valid()) {
         uint32_t new_player_id = this->find_empty_player_slot();
         do {
@@ -197,7 +201,7 @@ void GameRoot3D::set_game_mode(gd::Ref<GameMode> prototype) {
 }
 
 GameMode *GameRoot3D::get_game_mode() const {
-    return this->game_mode.ptr();
+    return this->game_mode;
 }
 
 GameState *GameRoot3D::get_game_state() const {

game_root.hpp

@@ -58,7 +58,7 @@ public:
     bool initialize_player(IPlayer *player, uint32_t id);
 
     /*! Un-set game mode.
-     * Shorthand for set_game_mode(Ref<GameMode>())
+     * Shorthand for `set_game_mode(Ref<PackedScene>())`
      */
     void reset_game_mode();
 
@@ -91,7 +91,7 @@ public:
      *
      * Replaces game mode requires destroying and respawning all players
      */
-    void set_game_mode(gd::Ref<GameMode> prototype);
+    void set_game_mode(gd::Ref<gd::PackedScene> prototype);
     //! get the current active game mode.
     GameMode *get_game_mode() const;
     //! Get the current active game state.
@@ -134,7 +134,7 @@ private:
     gd::RandomNumberGenerator rng{}; //!< Global random number generator.
     gd::HashMap<gd::StringName, Level3D*> levels{}; //!< all currently active levels identified by their resource paths.
     gd::Vector<SpawnPoint3D*> spawn_points{}; //!< all currently available spawn points.
-    gd::Ref<GameMode> game_mode{}; //!< current active gamemode.
+    GameMode *game_mode{}; //!< current active gamemode.
     /*! Active game state.
      *
      * Will be assigned loaded save data, or game_state_prototype if no save data is found.

level.cpp

@@ -1,17 +1,24 @@
 #include "level.hpp"
+#include "godot_cpp/core/class_db.hpp"
 #include "utils/godot_macros.hpp"
+#include <godot_cpp/classes/scene_state.hpp>
 
 namespace utils {
 void Level3D::_bind_methods() {
 #define CLASSNAME Level3D
-    GDPROPERTY_HINTED(game_mode_prototype, gd::Variant::OBJECT, gd::PROPERTY_HINT_RESOURCE_TYPE, "GameMode");
+    GDPROPERTY_HINTED(game_mode_prototype, gd::Variant::OBJECT, gd::PROPERTY_HINT_RESOURCE_TYPE, "PackedScene");
 }
 
-void Level3D::set_game_mode_prototype(gd::Ref<GameMode> prototype) {
+void Level3D::set_game_mode_prototype(gd::Ref<gd::PackedScene> prototype) {
+    if(prototype.is_null() || !prototype.is_valid())
+        this->game_mode_prototype = gd::Ref<gd::PackedScene>(nullptr);
+    else if(!gd::ClassDB::is_parent_class(prototype->get_state()->get_node_type(0), "GameMode"))
+        return;
+    else
         this->game_mode_prototype = prototype;
 }
 
-gd::Ref<GameMode> Level3D::get_game_mode_prototype() const {
+gd::Ref<gd::PackedScene> Level3D::get_game_mode_prototype() const {
     return this->game_mode_prototype;
 }
 }

level.hpp

@@ -15,10 +15,10 @@ class Level3D : public gd::Node3D {
     GDCLASS(Level3D, gd::Node3D);
     static void _bind_methods();
 public:
-    void set_game_mode_prototype(gd::Ref<GameMode> prototype);
+    void set_game_mode_prototype(gd::Ref<gd::PackedScene> prototype);
-    gd::Ref<GameMode> get_game_mode_prototype() const;
+    gd::Ref<gd::PackedScene> get_game_mode_prototype() const;
 private:
-    gd::Ref<GameMode> game_mode_prototype{}; //!< The starting state of the game mode to instantiate if this is the "leading" level.
+    gd::Ref<gd::PackedScene> game_mode_prototype{}; //!< The starting state of the game mode to instantiate if this is the "leading" level.
 };
 }