Merge pull request #257 from MaSzyna-EU07/fix/vehicle-removal-smoke

fix(gfx): a vehicle taken off the tracks stops smoking (#90)

tests/unit/test_smoke.cpp

@@ -0,0 +1,85 @@
+#include "stdafx.h"
+#include "doctest.h"
+
+#include "vehicle.h"
+
+#include "vehicle/smoke.h"
+
+// the smoke of a vehicle's engine: how many particles the smoke source of the vehicle's model spawns in an update
+
+namespace {
+
+// a source of 20 particles per second, with room for 100
+smoke::spawn_rate const source{0.f, 20.f, 1.f, 100.f};
+double const update{0.1}; // s
+
+// a diesel at work, its engine in the state of one of the cases below
+test::vehicle diesel() {
+	test::vehicle vehicle{test::definition::load("wagon")};
+	vehicle->MainCtrlPosNo = 1;
+	vehicle->DElist[1].RPM = 1500.0;
+	vehicle->enrot = 300.0;
+	vehicle->EnginePower = 400.0;
+	return vehicle;
+}
+
+} // namespace
+
+TEST_CASE("smoke: a vehicle taken off the tracks puffs no more (#90)") {
+	auto vehicle{diesel()};
+	SUBCASE("engine starting") { vehicle->dizel_spinup = true; }
+	SUBCASE("engine idling") { vehicle->DirAbsolute = 0; }
+	SUBCASE("engine under load") {
+		vehicle->DirAbsolute = 1;
+		vehicle->Im = 400.0;
+	}
+	// on the tracks the engine puffs
+	REQUIRE(smoke::vehicle_spawn_count(vehicle.mover(), true, source, update) >= 1.f);
+
+	// gone through a portal, the pending particles are dropped too
+	auto pending{source};
+	pending.pending = 5.f;
+	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), false, pending, update) == 0.f);
+}
+
+TEST_CASE("smoke: a road vehicle back on the road from the pool puffs again") {
+	auto vehicle{diesel()};
+	// waiting in the pool, the count stays at zero update after update
+	auto rate{source};
+	for (auto i{0}; i < 10; ++i) {
+		rate.pending = smoke::vehicle_spawn_count(vehicle.mover(), false, rate, update);
+	}
+	REQUIRE(rate.pending == 0.f);
+
+	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), true, rate, update) >= 1.f);
+}
+
+TEST_CASE("smoke: the engine adds to the steady rate of the source") {
+	auto vehicle{diesel()};
+	vehicle->DirAbsolute = 0;
+	auto const steady{source.rate * update}; // the rate of a source of the scenery
+
+	vehicle->EnginePower = 0.0;
+	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), true, source, update) == doctest::Approx(steady));
+
+	vehicle->EnginePower = 400.0;
+	auto const working{smoke::vehicle_spawn_count(vehicle.mover(), true, source, update)};
+	CHECK(working > steady);
+
+	// the faster the starting engine turns, the more it puffs
+	vehicle->dizel_spinup = true;
+	vehicle->enrot = 100.0;
+	auto const slow{smoke::vehicle_spawn_count(vehicle.mover(), true, source, update)};
+	vehicle->enrot = 400.0;
+	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), true, source, update) > slow);
+}
+
+TEST_CASE("smoke: the pending particles never outgrow the room of the source") {
+	auto vehicle{diesel()};
+	vehicle->dizel_spinup = true;
+	vehicle->enrot = 100000.0;
+	auto rate{source};
+	rate.pending = 99.f;
+
+	CHECK(smoke::vehicle_spawn_count(vehicle.mover(), true, rate, 10.0) == rate.limit);
+}