Replay: deterministic record & playback (#4)

Add deterministic record/playback for a run.

Recording captures `(seed, config hash, ordered tick-tagged commands)` and re-simulates on playback — no state snapshots. `DotaFactory.exe --replay <file>` re-plays a recorded run view-only with manual speed/pause.

Reviewed-on: #4
Co-authored-by: Malte Langkabel <malte.langkabel@gmail.com>
Co-committed-by: Malte Langkabel <malte.langkabel@gmail.com>

src/ui/GameWorldView.h

@@ -3,6 +3,7 @@
 #include <optional>
 #include <random>
 #include <set>
+#include <string>
 #include <vector>
 
 #include <QElapsedTimer>
@@ -26,10 +27,12 @@
 #include "ExitBuilderModeRequestedEvent.h"
 #include "DebugDrawToggledEvent.h"
 #include "BeamFiredEvent.h"
+#include "CommandRequestedEvent.h"
 #include "SchematicChoiceOption.h"
 #include "SpeedChangeRequestedEvent.h"
 
 #include "entt/entity/entity.hpp"
+#include "CommandManager.h"
 #include "EntitySelectedEvent.h"
 #include "GameConfig.h"
 #include "Rotation.h"
@@ -37,6 +40,9 @@
 #include "TickDriver.h"
 #include "VisualsConfig.h"
 
+struct Command;
+struct ParsedReplay;
+class ReplayPlayer;
 class Simulation;
 class QPainter;
 
@@ -56,13 +62,15 @@ class GameWorldView : public QOpenGLWidget,
                                                   DemolishModeToggleRequestedEvent,
                                                   BlueprintPlacementRequestedEvent,
                                                   ExitBlueprintModeRequestedEvent,
-                                                  SpeedChangeRequestedEvent>
+                                                  SpeedChangeRequestedEvent,
+                                                  CommandRequestedEvent>
 {
     Q_OBJECT
 
 public:
     GameWorldView(Simulation* sim, const GameConfig* config,
-                  const VisualsConfig* visuals, QWidget* parent = nullptr);
+                  const VisualsConfig* visuals, const std::string& configDir,
+                  const ParsedReplay* replay, QWidget* parent = nullptr);
     ~GameWorldView() override;
 
     double gameSpeed() const;
@@ -91,6 +99,17 @@ private:
     void handleEvent(std::shared_ptr<const BlueprintPlacementRequestedEvent> event) override;
     void handleEvent(std::shared_ptr<const ExitBlueprintModeRequestedEvent> event) override;
     void handleEvent(std::shared_ptr<const SpeedChangeRequestedEvent> event) override;
+    void handleEvent(std::shared_ptr<const CommandRequestedEvent> event) override;
+
+    // Enqueue a sim command onto the CommandManager (the single mutation path).
+    void enqueueCommand(std::shared_ptr<const Command> command);
+
+    // Enqueue a plain (unconfigured) building placement.
+    void enqueuePlaceBuilding(BuildingType type, QPoint anchor, Rotation rotation);
+
+    // True if the player can currently afford to place one building of `type`.
+    // Used to pre-validate placements whose UI follow-up depends on success.
+    bool canAfford(BuildingType type) const;
 
     void drawTiles(QPainter& painter);
     void drawBuildings(QPainter& painter);
@@ -104,6 +123,7 @@ private:
     void drawBeams(QPainter& painter);
     void drawOverlays(QPainter& painter);
     void drawScreenSpace(QPainter& painter);
+    void drawReplayOverlay(QPainter& painter);
 
     float    tilePx() const;
     float    viewportWidthTiles() const;
@@ -157,6 +177,14 @@ private:
     const GameConfig*    m_config;
     const VisualsConfig* m_visuals;
 
+    // Funnels all player input into the single Simulation::apply chokepoint.
+    CommandManager m_commandManager;
+    // A Reset command was enqueued; reset the view after the next drain applies it.
+    bool           m_viewResetPending = false;
+    // Non-null => view-only playback: ticks are driven by the recorded stream and
+    // live input is ignored (the CommandManager is in replay mode).
+    std::unique_ptr<ReplayPlayer> m_replayPlayer;
+
     TickDriver    m_tickDriver;
     QElapsedTimer m_frameTimer;
     std::mt19937  m_rng;