Add turbocharged twin scenario and cross-platform test harness

tests/two_stroke_regression.cpp

@@ -0,0 +1,87 @@
+#include "FluidSim/TwoStrokeScenario.hpp"
+#include "FluidSim/DynoCurve.hpp"
+#include <algorithm>
+#include <cmath>
+#include <iostream>
+#include <stdexcept>
+
+using namespace fluidsim::port;
+
+int main() {
+    TwoStrokeScenario scenario;
+    bool reed_open_seen = false, reed_closed_seen = false, above_old_limit = false;
+    DynoCurve dyno;
+    float peak = 0, maximum_rpm = 0;
+    for (int sample = 0; sample < 14 * 44100; ++sample) {
+        scenario.set_throttle(sample >= 2 * 44100 && sample < 6 * 44100 ? .6f : 0.f);
+        const auto audio = scenario.process();
+        if (!std::isfinite(audio.left) || !std::isfinite(audio.right))
+            throw std::runtime_error("Nonfinite two-stroke audio");
+        peak = std::max({peak, std::abs(audio.left), std::abs(audio.right)});
+        if (sample % 44 != 0)
+            continue;
+        const auto state = scenario.snapshot();
+        if (!std::isfinite(state.rpm) || !(state.cylinder_pressure > 0) ||
+            !(state.crankcase_pressure > 0) || !(state.intake_pressure > 0))
+            throw std::runtime_error("Invalid two-stroke physical state");
+        if (scenario.ecu.rev_limited() || scenario.cylinder.rev_limit_active)
+            throw std::runtime_error("Two-stroke rev limiter is active");
+        if (sample >= 2 * 44100 && sample < 6 * 44100) {
+            if (state.fuel_cut)
+                throw std::runtime_error("Two-stroke cut fuel with the pedal open");
+            above_old_limit |= state.rpm > 10200;
+        }
+        dyno.update(state.rpm, scenario.crankshaft.average_power / 1000,
+                    scenario.crankshaft.average_torque);
+        reed_open_seen |= state.reed_open;
+        reed_closed_seen |= !state.reed_open;
+        maximum_rpm = std::max(maximum_rpm, state.rpm);
+    }
+    const auto final = scenario.snapshot();
+    if (!above_old_limit)
+        throw std::runtime_error("Two-stroke did not exceed the old rev limit");
+    if (!reed_open_seen || !reed_closed_seen)
+        throw std::runtime_error("Reed did not open and close");
+    if (final.rpm < 2000 || final.rpm > 4000)
+        throw std::runtime_error("Two-stroke idle did not recover after throttle release");
+    if (peak >= 1)
+        throw std::runtime_error("Two-stroke audio exceeds device range");
+    for (const auto &pipe : scenario.pipes)
+        if (pipe.positivity_repairs != 0)
+            throw std::runtime_error("Two-stroke required pipe positivity repairs");
+    // Launch the same motorcycle used by the twin, then exercise gear controls.
+    scenario.shift_up();
+    scenario.set_controls(.7f, 0, 0);
+    for (int sample = 0; sample < 6 * 44100; ++sample) {
+        const auto audio = scenario.process();
+        if (!std::isfinite(audio.left) || !std::isfinite(audio.right))
+            throw std::runtime_error("Nonfinite motorcycle launch audio");
+        if (scenario.ecu.rev_limited())
+            throw std::runtime_error("Limiter re-enabled under motorcycle load");
+    }
+    if (scenario.vehicle.current_gear != 1 || scenario.vehicle.speed < 1 ||
+        !std::isfinite(scenario.vehicle.kinetic_energy()) || scenario.vehicle.engagement < .9f)
+        throw std::runtime_error("Two-stroke motorcycle did not launch with clutch engaged");
+    scenario.shift_up();
+    if (scenario.vehicle.current_gear != 2)
+        throw std::runtime_error("Two-stroke did not shift up");
+    scenario.shift_down();
+    if (scenario.vehicle.current_gear != 1)
+        throw std::runtime_error("Two-stroke did not shift down");
+    scenario.set_neutral();
+    if (scenario.vehicle.current_gear != 0)
+        throw std::runtime_error("Two-stroke neutral selection failed");
+    bool positive_power = false, positive_torque = false;
+    for (const auto& point : dyno.bins()) {
+        positive_power |= point.power_kw > 0;
+        positive_torque |= point.torque_nm > 0;
+    }
+    if (!positive_power || !positive_torque)
+        throw std::runtime_error("Two-stroke dyno did not record power and torque");
+    for (const auto& pipe : scenario.pipes)
+        if (pipe.positivity_repairs != 0)
+            throw std::runtime_error("Motorcycle launch required pipe positivity repairs");
+    std::cout << "Two-stroke regression passed: peak=" << peak << ", maximum RPM=" << maximum_rpm
+              << ", recovered RPM=" << final.rpm << ", bike speed=" << scenario.vehicle.speed * 3.6f
+              << " km/h\n";
+}