Improve physical geometry, fluid solvers, audio, and profiling

include/FluidSim/Engine.hpp

@@ -5,6 +5,7 @@
 #include <array>
 #include <cstddef>
 #include <random>
+#include <vector>
 
 namespace fluidsim::port {
 
@@ -33,11 +34,9 @@ private:
 };
 
 struct CylinderConfig {
-    float intake_open{340}, intake_close{590}, exhaust_open{130}, exhaust_close{390};
     float bore{0.075f}, stroke{0.068f}, rod{0.112f}, compression{11.5f};
     float intake_valve_diameter{0.030f}, exhaust_valve_diameter{0.028f};
     int intake_valve_count{1}, exhaust_valve_count{1};
-    float intake_valve_lift{0.005f}, exhaust_valve_lift{0.005f};
     float spark_advance{20.0f}, wiebe_a{5.0f}, wiebe_m{2.0f}, burn_duration{60.0f}, burn_start{5.0f};
     float afr{14.7f}, fuel_lhv{44.0e6f}, energy_variation{0.05f}, misfire_probability{};
     float wall_area{0.02f}, heat_transfer{100.0f}, ambient_temperature{300.0f};
@@ -79,14 +78,44 @@ protected:
     static bool crossed_angle(float previous, float current, float event) {
         return current >= previous ? previous < event && current >= event : event > previous || event <= current;
     }
-    static bool crossed_window_close(float previous, float current, float open, float close);
     void update_rev_limiter(float rpm, float dt);
     void sync_ports();
 };
 
 class FourStrokeCylinder final : public EngineCylinder {
 public:
+    struct CamPoint { float angle_degrees{}, lift_metres{}; };
+    struct ValveDynamics {
+        float mass_kg{0.035f};
+        float spring_rate_n_per_m{30000.f};
+        float damping_n_s_per_m{24.f};
+        float seat_force_n{100.f};
+        float maximum_lift_m{0.015f};
+        float seat_restitution{0.005f}, cam_restitution{0.01f}, stop_restitution{0.01f};
+    };
+    struct CamProfile { std::vector<CamPoint> points; };
+
+    void set_valve_profiles(const CamProfile& intake_cam, const ValveDynamics& intake_valve,
+                            const CamProfile& exhaust_cam, const ValveDynamics& exhaust_valve);
     float valve_area(float cycle_degrees, bool inlet) const override;
     void pre_step(Crankshaft& crank, float dt, float throttle) override;
+    float take_contact_impulse() { const float value=contact_impulse_;contact_impulse_=0;return value; }
+    bool valve_floating() const { return intake_floating_ || exhaust_floating_; }
+    float intake_lift() const { return intake_lift_; }
+    float exhaust_lift() const { return exhaust_lift_; }
+    static float cam_lift_at(const CamProfile& profile,float degrees) { return sample_cam(profile,degrees).lift_metres; }
+
+private:
+    struct ValveState { float lift{},velocity{};bool floating{}; };
+    const CamProfile* intake_cam_{};
+    const CamProfile* exhaust_cam_{};
+    ValveDynamics intake_dynamics_{},exhaust_dynamics_{};
+    ValveState intake_state_{},exhaust_state_{};
+    float intake_lift_{},exhaust_lift_{},contact_impulse_{};
+    bool intake_floating_{},exhaust_floating_{};
+
+    static CamPoint sample_cam(const CamProfile& profile,float degrees);
+    float advance_valve(ValveState& state,const CamProfile& cam,const ValveDynamics& dynamics,
+                        bool inlet,const Crankshaft& crank,float dt);
 };
 } // namespace fluidsim::port