Level traversal works, but it's very immediate. Next is a little 'confirm level' modal and a transition screen.

combat_ui.cpp

@@ -50,4 +50,9 @@ namespace gui {
     auto& meter = $gui.world().get<Meter>($meter);
     meter.percent = percent;
   }
+
+  void CombatUI::update_level(GameLevel &level) {
+    $level = level;
+    render();
+  }
 }

combat_ui.hpp

@@ -15,7 +15,7 @@ namespace gui {
 
       void render();
       void draw(sf::RenderWindow& window);
-      void update_level(GameLevel &level) { $level = level; }
+      void update_level(GameLevel &level);
       void set_damage(float percent);
   };
 }

gui_fsm.cpp

@@ -14,7 +14,7 @@ namespace gui {
 
   FSM::FSM() :
     $window(sf::VideoMode({SCREEN_WIDTH, SCREEN_HEIGHT}), "Zed's Raycaster Thing"),
-    $main_ui($window, $levels.current()),
+    $main_ui($window),
     $renderer($window),
     $level($levels.current()),
     $map_ui($level),
@@ -34,12 +34,13 @@ namespace gui {
       FSM_STATE(State, IDLE, ev);
       FSM_STATE(State, IN_COMBAT, ev);
       FSM_STATE(State, COMBAT_ROTATE, ev);
+      FSM_STATE(State, NEXT_LEVEL, ev);
       FSM_STATE(State, END, ev);
     }
   }
 
   void FSM::START(Event ) {
-    $main_ui.generate_map();
+    $main_ui.update_level($level);
     $level.world->set_the<Debug>({});
 
     $main_ui.init();
@@ -160,6 +161,9 @@ namespace gui {
       case CLOSE:
         dbc::log("Nothing to close.");
         break;
+      case STAIRS_DOWN:
+        state(State::NEXT_LEVEL);
+        break;
       case STOP_COMBAT:
       case TICK:
         // do nothing
@@ -169,6 +173,18 @@ namespace gui {
     }
   }
 
+  void FSM::NEXT_LEVEL(Event ev) {
+    using enum Event;
+
+    switch(ev) {
+      case TICK:
+        next_level();
+        state(State::IDLE);
+      default:
+        break; // do nothing for now
+    }
+  }
+
   void FSM::IN_COMBAT(Event ev) {
     using enum Event;
 
@@ -342,11 +358,13 @@ namespace gui {
             //      std::string(item.data["name"])));
             $status_ui.log("You picked up an item.");
             $status_ui.update();
-          }
-          break;
+          } break;
         case eGUI::ATTACK:
           event(Event::ATTACK);
           break;
+        case eGUI::STAIRS_DOWN:
+          event(Event::STAIRS_DOWN);
+          break;
         case eGUI::DEATH: {
             $status_ui.update();
             if(entity != player.entity) {
@@ -366,4 +384,16 @@ namespace gui {
       }
     }
   }
+
+  void FSM::next_level() {
+    $levels.create_level($level.world);
+    $level = $levels.next();
+
+    $status_ui.update_level($level);
+    $combat_ui.update_level($level);
+    $map_ui.update_level($level);
+    $main_ui.update_level($level);
+
+    run_systems();
+  }
 }

gui_fsm.hpp

@@ -19,6 +19,7 @@ namespace gui {
     ATTACKING,
     MAPPING,
     ROTATING,
+    NEXT_LEVEL,
     IDLE,
     END
   };
@@ -37,6 +38,7 @@ namespace gui {
     ATTACK,
     START_COMBAT,
     STOP_COMBAT,
+    STAIRS_DOWN,
     QUIT
   };
 
@@ -65,6 +67,7 @@ namespace gui {
       void IDLE(Event ev);
       void IN_COMBAT(Event ev);
       void COMBAT_ROTATE(Event ev);
+      void NEXT_LEVEL(Event ev);
       void END(Event ev);
 
       void try_move(int dir, bool strafe);
@@ -74,5 +77,6 @@ namespace gui {
       bool active();
       void run_systems();
       void handle_world_events();
+      void next_level();
   };
 }

inventory.cpp

@@ -15,6 +15,7 @@ namespace components {
   }
 
   bool Inventory::has_item(size_t at) {
+    fmt::println(">>> INVENTORY: requesting item at {}, have {} items in stock", at, items.size());
     return at < items.size();
   }
 

levelmanager.hpp

@@ -13,10 +13,10 @@ using std::shared_ptr;
 struct GameLevel {
   size_t index;
   DinkyECS::Entity player;
-  shared_ptr<Map> map;
-  shared_ptr<DinkyECS::World> world;
-  shared_ptr<lighting::LightRender> lights;
-  shared_ptr<SpatialMap> collision;
+  shared_ptr<Map> map = nullptr;
+  shared_ptr<DinkyECS::World> world = nullptr;
+  shared_ptr<lighting::LightRender> lights = nullptr;
+  shared_ptr<SpatialMap> collision = nullptr;
 };
 
 struct LevelScaling {

main_ui.cpp

@@ -4,9 +4,8 @@
 namespace gui {
   using namespace components;
 
-  MainUI::MainUI(sf::RenderWindow& window, GameLevel level) :
+  MainUI::MainUI(sf::RenderWindow& window) :
     $window(window),
-    $level(level),
     $overlay_ui($level),
     $rayview(RAY_VIEW_WIDTH, RAY_VIEW_HEIGHT)
   {
@@ -121,18 +120,20 @@ namespace gui {
     $camera.abort_plan($rayview);
   }
 
-  void MainUI::generate_map() {
-    auto& player = $level.world->get_the<Player>();
-    auto& player_position = $level.world->get<Position>(player.entity);
-    $player = player_position.location;
-    $rayview.set_level($level);
-  }
-
   void MainUI::dead_entity(DinkyECS::Entity entity) {
     auto &sprite = $level.world->get<Sprite>(entity);
     $rayview.update_sprite(entity, sprite);
   }
 
+  void MainUI::update_level(GameLevel level) {
+    $level = level;
+    auto& player_position = $level.world->get<Position>($level.player);
+    $player = player_position.location;
+    $rayview.update_level($level);
+    $rayview.position_camera($player.x + 0.5, $player.y + 0.5);
+    dirty();
+  }
+
   void MainUI::mouse(int x, int y) {
     $overlay_ui.$gui.mouse(x, y);
   }

main_ui.hpp

@@ -20,7 +20,7 @@ namespace gui {
     Raycaster $rayview;
     CameraLOL $camera;
 
-    MainUI(sf::RenderWindow& window, GameLevel level);
+    MainUI(sf::RenderWindow& window);
 
     void mouse(int x, int y);
     void debug();
@@ -32,12 +32,12 @@ namespace gui {
     std::optional<Point> play_move();
     Point plan_move(int dir, bool strafe);
     void abort_plan();
+    void update_level(GameLevel level);
 
     void init();
     void draw();
     void dirty();
 
-    void generate_map();
     void dead_entity(DinkyECS::Entity entity);
   };
 }

raycaster.cpp

@@ -368,19 +368,18 @@ void Raycaster::update_sprite(DinkyECS::Entity ent, components::Sprite& sprite)
   $sprites.insert_or_assign(ent, sprite_txt);
 }
 
-void Raycaster::set_level(GameLevel level) {
+void Raycaster::update_level(GameLevel level) {
   $level = level;
+
   auto& tiles = $level.map->tiles();
-  auto world = $level.world;
-  auto& player = world->get_the<components::Player>();
   $map = textures::convert_char_to_texture(tiles.$tile_ids);
 
-  world->query<components::Sprite>([&](const auto ent, auto& sprite) {
+  $level.world->query<components::Sprite>([&](const auto ent, auto& sprite) {
       // player doesn't need a sprite
-      if(player.entity == ent) return;
+      if($level.player == ent) return;
       fmt::println("entity {} will have sprite named {}", ent, sprite.name);
       auto sprite_txt = textures::get(sprite.name);
-      $sprites.try_emplace(ent, sprite_txt);
+      $sprites.insert_or_assign(ent, sprite_txt);
   });
 }
 

raycaster.hpp

@@ -34,9 +34,10 @@ struct Raycaster {
   int $height;
   int $screen_pos_x = RAY_VIEW_X;
   int $screen_pos_y = RAY_VIEW_Y;
+  std::unordered_map<DinkyECS::Entity, textures::SpriteTexture> $sprites;
+
   GameLevel $level;
   Matrix $map;
-  std::unordered_map<DinkyECS::Entity, textures::SpriteTexture> $sprites;
   std::vector<double> $zbuffer; // width
 
   Raycaster(int width, int height);
@@ -57,7 +58,7 @@ struct Raycaster {
     return ((y) * $width) + (x);
   }
 
-  void set_level(GameLevel level);
+  void update_level(GameLevel level);
   void update_sprite(DinkyECS::Entity ent, components::Sprite& sprite);
   void init_shaders();
 };

status_ui.cpp

@@ -59,6 +59,7 @@ namespace gui {
       auto& inventory = world->get<components::Inventory>($level.player);
       size_t inv_id = $slots[any_cast<string>(slot_name)];
 
+      if(inventory.has_item(inv_id)) {
         auto [used, name] = inventory.use($level, inv_id);
 
         if(used) {
@@ -70,6 +71,7 @@ namespace gui {
         update();
       }
     }
+  }
 
   /* WARNING: This is really not the greatest way to do this. */
   void StatusUI::update() {
@@ -118,4 +120,9 @@ namespace gui {
       $messages.pop_back();
     }
   }
+
+  void StatusUI::update_level(GameLevel &level) {
+    $level = level;
+    render();
+  }
 }

status_ui.hpp

@@ -16,7 +16,7 @@ namespace gui {
 
       StatusUI(GameLevel level);
       void select_slot(DinkyECS::Entity ent, std::any data);
-      void update_level(GameLevel &level) { $level = level; }
+      void update_level(GameLevel &level);
       void log(std::string msg);
       void render();
       void draw(sf::RenderWindow &window);

systems.cpp

@@ -254,8 +254,13 @@ void System::device(DinkyECS::World &world, DinkyECS::Entity actor, DinkyECS::En
   auto& device = world.get<Device>(item);
 
   for(auto event : device.events) {
-    // world.send<Events::GUI>((Events::GUI)event, actor, device);
-    fmt::println("BROKEN can't sent device event {}", event);
+    fmt::println("Device event received {}", event);
+
+    if(event == "Events::GUI::STAIRS_DOWN") {
+      world.send<Events::GUI>(Events::GUI::STAIRS_DOWN, actor, device);
+    } else {
+      dbc::log(fmt::format("EVENT IGNORED {}", event));
+    }
   }
 
   println("entity {} INTERACTED WITH DEVICE {}", actor, item);

worldbuilder.cpp

@@ -244,12 +244,14 @@ void WorldBuilder::randomize_entities(DinkyECS::World &world, GameConfig &config
 }
 
 void WorldBuilder::place_stairs(DinkyECS::World& world, GameConfig& config) {
+  for(size_t i = 1; i < $map.room_count() - 1; i++) {
     auto& device_config = config.devices.json();
     auto entity_data = device_config["STAIRS_DOWN"];
-  int last_room = $map.room_count() - 1;
+    int last_room = i;
     auto entity = configure_entity_in_map(world, entity_data, last_room);
     check_player(world, entity);
   }
+}
 
 void WorldBuilder::place_entities(DinkyECS::World &world) {
   auto &config = world.get_the<GameConfig>();