add restart button to game over screen

src/lib/sim/Simulation.cpp

@@ -49,6 +49,45 @@ Simulation::Simulation(const GameConfig& config, unsigned int seed)
 
 Simulation::~Simulation() = default;
 
+void Simulation::reset(unsigned int seed)
+{
+    m_rng.seed(seed);
+    m_currentTick              = 0;
+    m_nextId                   = 1;
+    m_buildingBlocksStock      = m_config.world.startingBuildingBlocks;
+    m_gameOver                 = false;
+    m_hqId                     = kInvalidEntityId;
+    m_playerStation1Id         = kInvalidEntityId;
+    m_playerStation2Id         = kInvalidEntityId;
+    m_currentEnemyStationIds[0] = kInvalidEntityId;
+    m_currentEnemyStationIds[1] = kInvalidEntityId;
+    m_fireEvents.clear();
+    m_blueprintDropEvents.clear();
+
+    m_beltSystem = BeltSystem(m_config.world.beltSpeedTilesPerSecond);
+    m_buildingSystem = std::make_unique<BuildingSystem>(
+        m_config,
+        m_beltSystem,
+        [this]() { return allocateId(); },
+        [this](int amount) { m_buildingBlocksStock += amount; },
+        m_rng);
+    m_shipSystem  = std::make_unique<ShipSystem>(m_config, [this]() { return allocateId(); });
+    m_scrapSystem = std::make_unique<ScrapSystem>([this]() { return allocateId(); });
+    m_waveSystem  = std::make_unique<WaveSystem>(m_config, m_rng);
+    m_combatSystem = std::make_unique<CombatSystem>(m_config);
+
+    m_blueprintLevels.clear();
+    for (const ShipDef& def : m_config.ships.ships)
+    {
+        BlueprintState state;
+        state.unlocked = def.availableFromStart;
+        state.level    = def.availableFromStart ? def.blueprint.playerProductionLevel : 0;
+        m_blueprintLevels[def.id] = state;
+    }
+
+    placeInitialStructures();
+}
+
 // ---------------------------------------------------------------------------
 // tick
 // ---------------------------------------------------------------------------