Add road vehicle flags for whether any part is on level crossing

src/road_cmd.cpp

@@ -2878,6 +2878,7 @@ static VehicleEnterTileStatus VehicleEnter_Road(Vehicle *v, TileIndex tile, int
 		case ROAD_TILE_CROSSING: {
 			if (v->type != VEH_ROAD) break;
 			SetCrossingOccupiedByRoadVehicle(tile, true);
+			SetBit(RoadVehicle::From(v->First())->rvflags, RVF_ON_LEVEL_CROSSING);
 			break;
 		}
 

src/roadveh.h

@@ -132,6 +132,10 @@ struct RoadVehPathCache {
 	}
 };
 
+enum RoadVehicleFlags {
+	RVF_ON_LEVEL_CROSSING             = 0, ///< One or more parts of this road vehicle are on a level crossing
+};
+
 /**
  * Buses, trucks and trams belong to this class.
  */
@@ -150,6 +154,8 @@ struct RoadVehicle FINAL : public GroundVehicle<RoadVehicle, VEH_ROAD> {
 
 	byte critical_breakdown_count; ///< Counter for the number of critical breakdowns since last service
 
+	uint8 rvflags;                 ///< Road vehicle flags
+
 	/** We don't want GCC to zero our struct! It already is zeroed and has an index! */
 	RoadVehicle() : GroundVehicleBase() {}
 	/** We want to 'destruct' the right class. */

src/roadveh_cmd.cpp

@@ -631,8 +631,11 @@ static void RoadVehCrash(RoadVehicle *v)
 
 static bool RoadVehCheckTrainCrash(RoadVehicle *v)
 {
+	if (!HasBit(v->rvflags, RVF_ON_LEVEL_CROSSING)) return false;
 	if (HasBit(_roadtypes_non_train_colliding, v->roadtype)) return false;
 
+	bool still_on_level_crossing = false;
+
 	for (RoadVehicle *u = v; u != nullptr; u = u->Next()) {
 		if (u->state == RVSB_WORMHOLE) continue;
 
@@ -640,6 +643,8 @@ static bool RoadVehCheckTrainCrash(RoadVehicle *v)
 
 		if (!IsLevelCrossingTile(tile)) continue;
 
+		still_on_level_crossing = true;
+
 		CheckRoadVehCrashTrainInfo info(u);
 		FindVehicleOnPosXY(v->x_pos, v->y_pos, VEH_TRAIN, &info, EnumCheckRoadVehCrashTrain);
 		if (info.found) {
@@ -648,6 +653,10 @@ static bool RoadVehCheckTrainCrash(RoadVehicle *v)
 		}
 	}
 
+	if (!still_on_level_crossing) {
+		ClrBit(v->rvflags, RVF_ON_LEVEL_CROSSING);
+	}
+
 	return false;
 }
 

src/saveload/afterload.cpp

@@ -4237,6 +4237,14 @@ bool AfterLoadGame()
 		_settings_game.economy.tick_rate = IsSavegameVersionUntil(SLV_MORE_CARGO_AGE) ? TRM_TRADITIONAL : TRM_MODERN;
 	}
 
+	if (SlXvIsFeatureMissing(XSLFI_ROAD_VEH_FLAGS)) {
+		for (RoadVehicle *rv : RoadVehicle::Iterate()) {
+			if (IsLevelCrossingTile(rv->tile)) {
+				SetBit(rv->First()->rvflags, RVF_ON_LEVEL_CROSSING);
+			}
+		}
+	}
+
 	if (SlXvIsFeatureMissing(XSLFI_AI_START_DATE) && IsSavegameVersionBefore(SLV_AI_START_DATE)) {
 		/* For older savegames, we don't now the actual interval; so set it to the newgame value. */
 		_settings_game.difficulty.competitors_interval = _settings_newgame.difficulty.competitors_interval;

src/sl/extended_ver_sl.cpp

@@ -189,6 +189,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_REMAIN_NEXT_ORDER_STATION,        XSCF_IGNORABLE_UNKNOWN,   1,   1, "remain_next_order_station",        nullptr, nullptr, nullptr          },
 	{ XSLFI_LABEL_ORDERS,                     XSCF_NULL,                2,   2, "label_orders",                     nullptr, nullptr, nullptr          },
 	{ XSLFI_VARIABLE_TICK_RATE,               XSCF_IGNORABLE_ALL,       1,   1, "variable_tick_rate",               nullptr, nullptr, nullptr          },
+	{ XSLFI_ROAD_VEH_FLAGS,                   XSCF_NULL,                1,   1, "road_veh_flags",                   nullptr, nullptr, nullptr          },
 	{ XSLFI_SCRIPT_INT64,                     XSCF_NULL,                1,   1, "script_int64",                     nullptr, nullptr, nullptr          },
 	{ XSLFI_U64_TICK_COUNTER,                 XSCF_NULL,                1,   1, "u64_tick_counter",                 nullptr, nullptr, nullptr          },
 	{ XSLFI_LINKGRAPH_TRAVEL_TIME,            XSCF_NULL,                1,   1, "linkgraph_travel_time",            nullptr, nullptr, nullptr          },

src/sl/extended_ver_sl.h

@@ -140,6 +140,7 @@ enum SlXvFeatureIndex {
 	XSLFI_REMAIN_NEXT_ORDER_STATION,              ///< Remain in station if next order is for same station
 	XSLFI_LABEL_ORDERS,                           ///< Label orders
 	XSLFI_VARIABLE_TICK_RATE,                     ///< Variable tick rate
+	XSLFI_ROAD_VEH_FLAGS,                         ///< Road vehicle flags
 
 	XSLFI_SCRIPT_INT64,                           ///< See: SLV_SCRIPT_INT64
 	XSLFI_U64_TICK_COUNTER,                       ///< See: SLV_U64_TICK_COUNTER

src/sl/vehicle_sl.cpp

@@ -871,6 +871,7 @@ SaveLoadTable GetVehicleDescription(VehicleType vt)
 		 SLE_CONDNULL(2,                                                               SLV_6, SLV_131),
 		 SLE_CONDNULL(16,                                                              SLV_2, SLV_144), // old reserved space
 		SLE_CONDVAR_X(RoadVehicle, critical_breakdown_count, SLE_UINT8,       SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_IMPROVED_BREAKDOWNS, 6)),
+		SLE_CONDVAR_X(RoadVehicle, rvflags,                  SLE_UINT8,       SL_MIN_VERSION, SL_MAX_VERSION, SlXvFeatureTest(XSLFTO_AND, XSLFI_ROAD_VEH_FLAGS)),
 	};
 
 	static const SaveLoad _ship_desc[] = {

src/vehicle.cpp

@@ -4279,6 +4279,11 @@ void DumpVehicleFlagsGeneric(const Vehicle *v, T dump, U dump_header)
 		dump('X', "VRF_PENDING_SPEED_RESTRICTION",     HasBit(t->flags, VRF_PENDING_SPEED_RESTRICTION));
 		dump('c', "VRF_SPEED_ADAPTATION_EXEMPT",       HasBit(t->flags, VRF_SPEED_ADAPTATION_EXEMPT));
 	}
+	if (v->type == VEH_ROAD) {
+		const RoadVehicle *rv = RoadVehicle::From(v);
+		dump_header("rvf:", "road vehicle flags:");
+		dump('L', "RVF_ON_LEVEL_CROSSING",             HasBit(rv->rvflags, RVF_ON_LEVEL_CROSSING));
+	}
 }
 
 char *Vehicle::DumpVehicleFlags(char *b, const char *last, bool include_tile) const