feat(demo): transició per fosa a/desde negre en el salt títol→demo

source/game/scenes/title_scene.cpp

@@ -37,7 +37,8 @@ namespace {
 TitleScene::TitleScene(SDLManager& sdl, SceneContext& context)
     : sdl_(sdl),
       context_(context),
-      text_(sdl.getRenderer()) {
+      text_(sdl.getRenderer()),
+      fade_(sdl.getRenderer()) {
     std::cout << "SceneType Titol: Inicialitzant...\n";
 
     match_config_.player1_active = false;
@@ -333,6 +334,9 @@ void TitleScene::update(float delta_time) {
         case TitleState::BLACK_SCREEN:
             updateBlackScreenState(delta_time);
             break;
+        case TitleState::DEMO_FADE_OUT:
+            updateDemoFadeOutState(delta_time);
+            break;
     }
 
     // Les animacions segueixen pero els inputs es bloquegen mentre el menu
@@ -368,7 +372,12 @@ void TitleScene::update(float delta_time) {
             demo_cfg.player2_active = (SC.players >= 2);
             demo_cfg.mode = GameConfig::Mode::DEMO;
             context_.setMatchConfig(demo_cfg);
-            context_.setNextScene(SceneType::GAME);
+            // No saltem en sec: fosa a negre i, en acabar, canvi a GAME (el salt
+            // real el fa updateDemoFadeOutState). L'estat deixa de ser MAIN, així
+            // que ni es re-dispara la demo ni s'accepta START durant la fosa.
+            current_state_ = TitleState::DEMO_FADE_OUT;
+            fade_.start(0.0F, 1.0F, Defaults::Game::Fade::DEMO_OUT_DURATION);
+            temps_acumulat_ = 0.0F;
         }
     }
 }
@@ -473,6 +482,13 @@ void TitleScene::updateBlackScreenState(float delta_time) {
     }
 }
 
+void TitleScene::updateDemoFadeOutState(float delta_time) {
+    fade_.update(delta_time);
+    if (fade_.isDone()) {
+        context_.setNextScene(SceneType::GAME);
+    }
+}
+
 void TitleScene::handleSkipInput() {
     if (current_state_ != TitleState::STARFIELD_FADE_IN && current_state_ != TitleState::STARFIELD) {
         return;
@@ -577,7 +593,8 @@ void TitleScene::draw() {
         (current_state_ == TitleState::STARFIELD_FADE_IN ||
             current_state_ == TitleState::STARFIELD ||
             current_state_ == TitleState::MAIN ||
-            current_state_ == TitleState::PLAYER_JOIN_PHASE)) {
+            current_state_ == TitleState::PLAYER_JOIN_PHASE ||
+            current_state_ == TitleState::DEMO_FADE_OUT)) {
         ship_animator_->draw();
     }
     drawFlashes();
@@ -586,7 +603,12 @@ void TitleScene::draw() {
         return;
     }
 
-    if (current_state_ != TitleState::MAIN && current_state_ != TitleState::PLAYER_JOIN_PHASE) {
+    // DEMO_FADE_OUT es pinta com MAIN (logo + text) perquè el títol segueixi
+    // visible sota la fosa a negre.
+    if (current_state_ != TitleState::MAIN &&
+        current_state_ != TitleState::PLAYER_JOIN_PHASE &&
+        current_state_ != TitleState::DEMO_FADE_OUT) {
+        fade_.draw();  // BLACK_SCREEN i altres: només la fosa (si activa)
         return;
     }
 
@@ -657,6 +679,9 @@ void TitleScene::draw() {
     }
 
     dibuixarPeuTitol(SPACING);
+
+    // Fosa a negre (attract): per damunt de tot. No-op si no està activa.
+    fade_.draw();
 }
 
 auto TitleScene::checkSkipButtonPressed() -> bool {