init commit

engine/simulation.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include "engine.h"
+#include "transmission.h"
+#include "vehicle.h"
+
+// Owns Engine + Transmission + Vehicle and sequences the per-tick
+// coupling between them. This is the thing main.cpp / the GUI talks to.
+class Simulation {
+public:
+    void step(double dt);
+
+    const Engine& engine() const { return m_engine; }
+    const Transmission& transmission() const { return m_transmission; }
+    const Vehicle& vehicle() const { return m_vehicle; }
+
+    Engine& engine() { return m_engine; } // for reset, etc.
+    Transmission& transmission() { return m_transmission; } // for gear shifts
+
+private:
+    Engine m_engine;
+    Transmission m_transmission;
+    Vehicle m_vehicle;
+};