implement load config on game restart

src/lib/config/GameConfig.h

@@ -6,8 +6,8 @@
 #include "ShipsConfig.h"
 #include "StationsConfig.h"
 
-// Aggregate of all five simulation config files, loaded once at startup and
-// immutable for the rest of the game. See architecture.md "Config Loading".
+// Aggregate of all five simulation config files. Loaded at startup and reloaded
+// from disk on each game restart (REQ-CFG-RELOAD). See architecture.md "Config Loading".
 struct GameConfig
 {
     WorldConfig world;

src/lib/sim/Simulation.cpp

@@ -9,23 +9,23 @@
 #include "SurfaceMask.h"
 #include "WaveSystem.h"
 
-Simulation::Simulation(const GameConfig& config, unsigned int seed)
-    : m_config(config)
+Simulation::Simulation(GameConfig config, unsigned int seed)
+    : m_config(std::move(config))
     , m_rng(seed)
     , m_currentTick(0)
     , m_nextId(1)
-    , m_buildingBlocksStock(config.world.startingBuildingBlocks)
+    , m_buildingBlocksStock(m_config.world.startingBuildingBlocks)
     , m_gameOver(false)
     , m_hqId(kInvalidEntityId)
     , m_playerStation1Id(kInvalidEntityId)
     , m_playerStation2Id(kInvalidEntityId)
-    , m_beltSystem(config.world.beltSpeedTilesPerSecond)
+    , m_beltSystem(m_config.world.beltSpeedTilesPerSecond)
 {
     m_currentEnemyStationIds[0] = kInvalidEntityId;
     m_currentEnemyStationIds[1] = kInvalidEntityId;
 
     m_buildingSystem = std::make_unique<BuildingSystem>(
-        config,
+        m_config,
         m_beltSystem,
         [this]() { return allocateId(); },
         [this](int amount) { m_buildingBlocksStock += amount; },
@@ -39,13 +39,13 @@ Simulation::Simulation(const GameConfig& config, unsigned int seed)
             m_shipSystem->spawn(id, it->second.level, pos, /*isEnemy=*/false);
         },
         m_rng);
-    m_shipSystem  = std::make_unique<ShipSystem>(config, [this]() { return allocateId(); });
+    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>(config, m_rng);
-    m_combatSystem = std::make_unique<CombatSystem>(config);
+    m_waveSystem  = std::make_unique<WaveSystem>(m_config, m_rng);
+    m_combatSystem = std::make_unique<CombatSystem>(m_config);
 
     // Initialize blueprint unlock state.
-    for (const ShipDef& def : config.ships.ships)
+    for (const ShipDef& def : m_config.ships.ships)
     {
         BlueprintState state;
         state.unlocked = def.availableFromStart;
@@ -58,6 +58,17 @@ Simulation::Simulation(const GameConfig& config, unsigned int seed)
 
 Simulation::~Simulation() = default;
 
+const GameConfig& Simulation::config() const
+{
+    return m_config;
+}
+
+void Simulation::reset(GameConfig newConfig, unsigned int seed)
+{
+    m_config = std::move(newConfig);
+    reset(seed);
+}
+
 void Simulation::reset(unsigned int seed)
 {
     m_rng.seed(seed);

src/lib/sim/Simulation.h

@@ -26,12 +26,17 @@ class WaveSystem;
 class Simulation
 {
 public:
-    explicit Simulation(const GameConfig& config, unsigned int seed = 0);
+    explicit Simulation(GameConfig config, unsigned int seed = 0);
     ~Simulation();
 
+    const GameConfig& config() const;
+
     // Reinitializes all simulation state as if constructed fresh.
     void reset(unsigned int seed = 0);
 
+    // Reloads config then reinitializes all simulation state.
+    void reset(GameConfig newConfig, unsigned int seed = 0);
+
     // Advances the simulation by one tick. Tick order per architecture.md §Tick Order.
     void tick();
 
@@ -83,7 +88,7 @@ private:
     // Award a random blueprint drop (REQ-DEF-BLUEPRINT-DROP) and emit the event.
     void awardBlueprintDrop();
 
-    const GameConfig& m_config;
+    GameConfig m_config;
     std::mt19937 m_rng;
 
     Tick     m_currentTick;