(svn r16717) -Codechange: make IsFrontEngine() member of Train

17 files changed, 115 insertions, 107 deletions

diff --git a/src/autoreplace_cmd.cpp b/src/autoreplace_cmd.cpp
index 27be93e7a..f8faeab10 100644
--- a/src/autoreplace_cmd.cpp
+++ b/src/autoreplace_cmd.cpp
@@ -617,9 +617,10 @@ CommandCost CmdAutoreplaceVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1
 
 	bool free_wagon = false;
 	if (v->type == VEH_TRAIN) {
-		if (IsArticulatedPart(v) || IsRearDualheaded(v)) return CMD_ERROR;
-		free_wagon = !IsFrontEngine(v);
-		if (free_wagon && IsFrontEngine(v->First())) return CMD_ERROR;
+		Train *t = Train::From(v);
+		if (IsArticulatedPart(t) || IsRearDualheaded(t)) return CMD_ERROR;
+		free_wagon = !t->IsFrontEngine();
+		if (free_wagon && t->First()->IsFrontEngine()) return CMD_ERROR;
 	} else {
 		if (!v->IsPrimaryVehicle()) return CMD_ERROR;
 	}
diff --git a/src/depot_gui.cpp b/src/depot_gui.cpp
index 6618d0b40..e1612c680 100644
--- a/src/depot_gui.cpp
+++ b/src/depot_gui.cpp
@@ -437,11 +437,11 @@ struct DepotWindow : Window {
 
 		switch (this->type) {
 			case VEH_TRAIN: {
-				const Vehicle *v = *veh;
+				const Train *v = Train::From(*veh);
 				d->head = d->wagon = v;
 
 				/* either pressed the flag or the number, but only when it's a loco */
-				if (x < 0 && IsFrontEngine(v)) return (x >= -10) ? MODE_START_STOP : MODE_SHOW_VEHICLE;
+				if (x < 0 && v->IsFrontEngine()) return (x >= -10) ? MODE_START_STOP : MODE_SHOW_VEHICLE;
 
 				skip = (skip * 8) / _traininfo_vehicle_width;
 				x = (x * 8) / _traininfo_vehicle_width;
@@ -450,7 +450,7 @@ struct DepotWindow : Window {
 				x += skip;
 
 				/* find the vehicle in this row that was clicked */
-				while (v != NULL && (x -= Train::From(v)->tcache.cached_veh_length) >= 0) v = v->Next();
+				while (v != NULL && (x -= v->tcache.cached_veh_length) >= 0) v = v->Next();
 
 				/* if an articulated part was selected, find its parent */
 				while (v != NULL && IsArticulatedPart(v)) v = v->Previous();
@@ -564,7 +564,7 @@ struct DepotWindow : Window {
 		if (!v->IsPrimaryVehicle()) {
 			v = v->First();
 			/* Do nothing when clicking on a train in depot with no loc attached */
-			if (v->type == VEH_TRAIN && !IsFrontEngine(v)) return;
+			if (v->type == VEH_TRAIN && !Train::From(v)->IsFrontEngine()) return;
 		}
 
 		switch (v->type) {
@@ -950,7 +950,7 @@ struct DepotWindow : Window {
 							DoCommandP(Vehicle::Get(sel)->tile, Vehicle::Get(sel)->index, true, CMD_REVERSE_TRAIN_DIRECTION | CMD_MSG(STR_ERROR_CAN_T_MAKE_VEHICLE_TURN));
 						} else if (gdvp.wagon == NULL || gdvp.wagon->index != sel) {
 							TrainDepotMoveVehicle(gdvp.wagon, sel, gdvp.head);
-						} else if (gdvp.head != NULL && IsFrontEngine(gdvp.head)) {
+						} else if (gdvp.head != NULL && Train::From(gdvp.head)->IsFrontEngine()) {
 							ShowVehicleViewWindow(gdvp.head);
 						}
 					}
@@ -977,7 +977,7 @@ struct DepotWindow : Window {
 
 					int sell_cmd = (v->type == VEH_TRAIN && (widget == DEPOT_WIDGET_SELL_CHAIN || _ctrl_pressed)) ? 1 : 0;
 
-					bool is_engine = (!(v->type == VEH_TRAIN && !IsFrontEngine(v)));
+					bool is_engine = (v->type != VEH_TRAIN || Train::From(v)->IsFrontEngine());
 
 					if (is_engine) {
 						_backup_orders_tile = v->tile;
diff --git a/src/elrail.cpp b/src/elrail.cpp
index 901f46dde..ea0834041 100644
--- a/src/elrail.cpp
+++ b/src/elrail.cpp
@@ -568,7 +568,7 @@ bool SettingsDisableElrail(int32 p1)
 	/* Fix the total power and acceleration for trains */
 	FOR_ALL_TRAINS(t) {
 		/* power and acceleration is cached only for front engines */
-		if (IsFrontEngine(t)) {
+		if (t->IsFrontEngine()) {
 			TrainPowerChanged(t);
 			UpdateTrainAcceleration(t);
 		}
diff --git a/src/group.h b/src/group.h
index 762f915f4..6f92659e6 100644
--- a/src/group.h
+++ b/src/group.h
@@ -83,8 +83,8 @@ static inline void DecreaseGroupNumVehicle(GroupID id_g)
 
 
 void InitializeGroup();
-void SetTrainGroupID(Vehicle *v, GroupID grp);
-void UpdateTrainGroupID(Vehicle *v);
+void SetTrainGroupID(Train *v, GroupID grp);
+void UpdateTrainGroupID(Train *v);
 void RemoveVehicleFromGroup(const Vehicle *v);
 void RemoveAllGroupsForCompany(const CompanyID company);
 
diff --git a/src/group_cmd.cpp b/src/group_cmd.cpp
index 1c1b78fee..cc07395e2 100644
--- a/src/group_cmd.cpp
+++ b/src/group_cmd.cpp
@@ -210,7 +210,7 @@ CommandCost CmdAddVehicleGroup(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 		switch (v->type) {
 			default: NOT_REACHED();
 			case VEH_TRAIN:
-				SetTrainGroupID(v, new_g);
+				SetTrainGroupID(Train::From(v), new_g);
 				break;
 			case VEH_ROAD:
 			case VEH_SHIP:
@@ -342,11 +342,11 @@ void RemoveVehicleFromGroup(const Vehicle *v)
  * @param v     First vehicle of the chain.
  * @param new_g index of array group
  */
-void SetTrainGroupID(Vehicle *v, GroupID new_g)
+void SetTrainGroupID(Train *v, GroupID new_g)
 {
 	if (!Group::IsValidID(new_g) && !IsDefaultGroupID(new_g)) return;
 
-	assert(v->type == VEH_TRAIN && IsFrontEngine(v));
+	assert(v->IsFrontEngine());
 
 	for (Vehicle *u = v; u != NULL; u = u->Next()) {
 		if (IsEngineCountable(u)) UpdateNumEngineGroup(u->engine_type, u->group_id, new_g);
@@ -366,11 +366,11 @@ void SetTrainGroupID(Vehicle *v, GroupID new_g)
  * @note Called in CmdBuildRailVehicle, CmdBuildRailWagon, CmdMoveRailVehicle, CmdSellRailWagon
  * @param v First vehicle of the chain.
  */
-void UpdateTrainGroupID(Vehicle *v)
+void UpdateTrainGroupID(Train *v)
 {
-	assert(v->type == VEH_TRAIN && (IsFrontEngine(v) || IsFreeWagon(v)));
+	assert(v->IsFrontEngine() || IsFreeWagon(v));
 
-	GroupID new_g = IsFrontEngine(v) ? v->group_id : (GroupID)DEFAULT_GROUP;
+	GroupID new_g = v->IsFrontEngine() ? v->group_id : (GroupID)DEFAULT_GROUP;
 	for (Vehicle *u = v; u != NULL; u = u->Next()) {
 		if (IsEngineCountable(u)) UpdateNumEngineGroup(u->engine_type, u->group_id, new_g);
 
diff --git a/src/industry_cmd.cpp b/src/industry_cmd.cpp
index 92d510cd2..22c9ede1e 100644
--- a/src/industry_cmd.cpp
+++ b/src/industry_cmd.cpp
@@ -2023,7 +2023,7 @@ int WhoCanServiceIndustry(Industry *ind)
 		/* Check whether it accepts the right kind of cargo */
 		bool c_accepts = false;
 		bool c_produces = false;
-		if (v->type == VEH_TRAIN && IsFrontEngine(v)) {
+		if (v->type == VEH_TRAIN && Train::From(v)->IsFrontEngine()) {
 			for (const Vehicle *u = v; u != NULL; u = u->Next()) {
 				CanCargoServiceIndustry(u->cargo_type, ind, &c_accepts, &c_produces);
 			}
diff --git a/src/saveload/afterload.cpp b/src/saveload/afterload.cpp
index c5534ddae..7defed1e6 100644
--- a/src/saveload/afterload.cpp
+++ b/src/saveload/afterload.cpp
@@ -985,7 +985,7 @@ bool AfterLoadGame()
 		}
 
 		FOR_ALL_TRAINS(v) {
-			if (IsFrontEngine(v) || IsFreeWagon(v)) TrainConsistChanged(v, true);
+			if (v->IsFrontEngine() || IsFreeWagon(v)) TrainConsistChanged(v, true);
 		}
 
 	}
@@ -1344,7 +1344,7 @@ bool AfterLoadGame()
 		Vehicle *v;
 		/* Added a FIFO queue of vehicles loading at stations */
 		FOR_ALL_VEHICLES(v) {
-			if ((v->type != VEH_TRAIN || IsFrontEngine(v)) &&  // for all locs
+			if ((v->type != VEH_TRAIN || Train::From(v)->IsFrontEngine()) &&  // for all locs
 					!(v->vehstatus & (VS_STOPPED | VS_CRASHED)) && // not stopped or crashed
 					v->current_order.IsType(OT_LOADING)) {         // loading
 				Station::Get(v->last_station_visited)->loading_vehicles.push_back(v);
diff --git a/src/saveload/vehicle_sl.cpp b/src/saveload/vehicle_sl.cpp
index cc1cb4326..3525d2591 100644
--- a/src/saveload/vehicle_sl.cpp
+++ b/src/saveload/vehicle_sl.cpp
@@ -28,7 +28,7 @@ void ConnectMultiheadedTrains()
 	}
 
 	FOR_ALL_TRAINS(v) {
-		if (IsFrontEngine(v) || IsFreeWagon(v)) {
+		if (v->IsFrontEngine() || IsFreeWagon(v)) {
 			/* Two ways to associate multiheaded parts to each other:
 			 * sequential-matching: Trains shall be arranged to look like <..>..<..>..<..>..
 			 * bracket-matching:    Free vehicle chains shall be arranged to look like ..<..<..>..<..>..>..
@@ -42,7 +42,7 @@ void ConnectMultiheadedTrains()
 			 *   This is why two matching strategies are needed.
 			 */
 
-			bool sequential_matching = IsFrontEngine(v);
+			bool sequential_matching = v->IsFrontEngine();
 
 			for (Train *u = v; u != NULL; u = GetNextVehicle(u)) {
 				if (u->other_multiheaded_part != NULL) continue; // we already linked this one
@@ -308,9 +308,12 @@ void AfterLoadVehicles(bool part_of_load)
 	FOR_ALL_VEHICLES(v) {
 		assert(v->first != NULL);
 
-		if (v->type == VEH_TRAIN && (IsFrontEngine(v) || IsFreeWagon(v))) {
-			if (IsFrontEngine(v)) Train::From(v)->tcache.last_speed = v->cur_speed; // update displayed train speed
-			TrainConsistChanged(Train::From(v), false);
+		if (v->type == VEH_TRAIN) {
+			Train *t = Train::From(v);
+			if (t->IsFrontEngine() || IsFreeWagon(t)) {
+				t->tcache.last_speed = t->cur_speed; // update displayed train speed
+				TrainConsistChanged(t, false);
+			}
 		} else if (v->type == VEH_ROAD && IsRoadVehFront(v)) {
 			RoadVehUpdateCache(RoadVehicle::From(v));
 		}
@@ -319,7 +322,7 @@ void AfterLoadVehicles(bool part_of_load)
 	/* Stop non-front engines */
 	if (CheckSavegameVersion(112)) {
 		FOR_ALL_VEHICLES(v) {
-			if (v->type == VEH_TRAIN && !IsFrontEngine(v)) {
+			if (v->type == VEH_TRAIN && !Train::From(v)->IsFrontEngine()) {
 				if (IsTrainEngine(v)) v->vehstatus |= VS_STOPPED;
 				/* cur_speed is now relevant for non-front parts - nonzero breaks
 				 * moving-wagons-inside-depot- and autoreplace- code */
diff --git a/src/settings.cpp b/src/settings.cpp
index 451c5b365..c5866204b 100644
--- a/src/settings.cpp
+++ b/src/settings.cpp
@@ -700,7 +700,7 @@ static bool UpdateConsists(int32 p1)
 	Train *t;
 	FOR_ALL_TRAINS(t) {
 		/* Update the consist of all trains so the maximum speed is set correctly. */
-		if (IsFrontEngine(t) || IsFreeWagon(t)) TrainConsistChanged(t, true);
+		if (t->IsFrontEngine() || IsFreeWagon(t)) TrainConsistChanged(t, true);
 	}
 	return true;
 }
@@ -736,7 +736,7 @@ static bool TrainAccelerationModelChanged(int32 p1)
 {
 	Train *t;
 	FOR_ALL_TRAINS(t) {
-		if (IsFrontEngine(t)) {
+		if (t->IsFrontEngine()) {
 			t->tcache.cached_max_curve_speed = GetTrainCurveSpeedLimit(t);
 			UpdateTrainAcceleration(t);
 		}
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index 7db3d6d6c..51e714f4d 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -2508,7 +2508,7 @@ static VehicleEnterTileStatus VehicleEnter_Station(Vehicle *v, TileIndex tile, i
 
 	if (v->type == VEH_TRAIN) {
 		if (!v->current_order.ShouldStopAtStation(v, station_id)) return VETSB_CONTINUE;
-		if (!IsRailwayStation(tile) || !IsFrontEngine(v)) return VETSB_CONTINUE;
+		if (!IsRailwayStation(tile) || !Train::From(v)->IsFrontEngine()) return VETSB_CONTINUE;
 
 		int station_ahead;
 		int station_length;
diff --git a/src/train.h b/src/train.h
index b52b52396..21e1995ea 100644
--- a/src/train.h
+++ b/src/train.h
@@ -51,17 +51,6 @@ enum TrainSubtype {
 	TS_MULTIHEADED       = 5, ///< Engine is a multiheaded
 };
 
-
-/** Check if a vehicle is front engine
- * @param v vehicle to check
- * @return Returns true if vehicle is a front engine
- */
-static inline bool IsFrontEngine(const Vehicle *v)
-{
-	assert(v->type == VEH_TRAIN);
-	return HasBit(v->subtype, TS_FRONT);
-}
-
 /** Set front engine state
  * @param v vehicle to change
  */
@@ -324,7 +313,7 @@ struct Train : public SpecializedVehicle<Train, VEH_TRAIN> {
 	void UpdateDeltaXY(Direction direction);
 	ExpensesType GetExpenseType(bool income) const { return income ? EXPENSES_TRAIN_INC : EXPENSES_TRAIN_RUN; }
 	void PlayLeaveStationSound() const;
-	bool IsPrimaryVehicle() const { return IsFrontEngine(this); }
+	bool IsPrimaryVehicle() const { return this->IsFrontEngine(); }
 	SpriteID GetImage(Direction direction) const;
 	int GetDisplaySpeed() const { return this->tcache.last_speed; }
 	int GetDisplayMaxSpeed() const { return this->tcache.cached_max_speed; }
@@ -336,6 +325,13 @@ struct Train : public SpecializedVehicle<Train, VEH_TRAIN> {
 	Trackdir GetVehicleTrackdir() const;
 	TileIndex GetOrderStationLocation(StationID station);
 	bool FindClosestDepot(TileIndex *location, DestinationID *destination, bool *reverse);
+
+	/**
+	 * Check if a vehicle is front engine
+	 * @param v vehicle to check
+	 * @return Returns true if vehicle is a front engine
+	 */
+	FORCEINLINE bool IsFrontEngine() const { return HasBit(this->subtype, TS_FRONT); }
 };
 
 #define FOR_ALL_TRAINS(var) FOR_ALL_VEHICLES_OF_TYPE(Train, var)
diff --git a/src/train_cmd.cpp b/src/train_cmd.cpp
index c6a1e9fed..a3e3179ee 100644
--- a/src/train_cmd.cpp
+++ b/src/train_cmd.cpp
@@ -217,11 +217,10 @@ void TrainConsistChanged(Train *v, bool same_length)
 {
 	uint16 max_speed = UINT16_MAX;
 
-	assert(v->type == VEH_TRAIN);
-	assert(IsFrontEngine(v) || IsFreeWagon(v));
+	assert(v->IsFrontEngine() || IsFreeWagon(v));
 
 	const RailVehicleInfo *rvi_v = RailVehInfo(v->engine_type);
-	EngineID first_engine = IsFrontEngine(v) ? v->engine_type : INVALID_ENGINE;
+	EngineID first_engine = v->IsFrontEngine() ? v->engine_type : INVALID_ENGINE;
 	v->tcache.cached_total_length = 0;
 	v->compatible_railtypes = RAILTYPES_NONE;
 
@@ -347,7 +346,7 @@ void TrainConsistChanged(Train *v, bool same_length)
 	/* recalculate cached weights and power too (we do this *after* the rest, so it is known which wagons are powered and need extra weight added) */
 	TrainCargoChanged(v);
 
-	if (IsFrontEngine(v)) {
+	if (v->IsFrontEngine()) {
 		UpdateTrainAcceleration(v);
 		InvalidateWindow(WC_VEHICLE_DETAILS, v->index);
 	}
@@ -483,7 +482,7 @@ static int GetTrainAcceleration(Train *v, bool mode)
 	assert(max_speed == GetTrainCurveSpeedLimit(v)); // safety check, will be removed later
 	int speed = v->cur_speed * 10 / 16; // km-ish/h -> mp/h
 
-	if (IsTileType(v->tile, MP_STATION) && IsFrontEngine(v)) {
+	if (IsTileType(v->tile, MP_STATION) && v->IsFrontEngine()) {
 		StationID sid = GetStationIndex(v->tile);
 		if (v->current_order.ShouldStopAtStation(v, sid)) {
 			int station_ahead;
@@ -577,7 +576,7 @@ static int GetTrainAcceleration(Train *v, bool mode)
 
 void UpdateTrainAcceleration(Train *v)
 {
-	assert(IsFrontEngine(v));
+	assert(v->IsFrontEngine());
 
 	v->max_speed = v->tcache.cached_max_speed;
 
@@ -939,7 +938,7 @@ int CheckTrainInDepot(const Train *v, bool needs_to_be_stopped)
 		 * Also skip counting rear ends of multiheaded engines */
 		if (!IsArticulatedPart(v) && !IsRearDualheaded(v)) count++;
 		if (v->track != TRACK_BIT_DEPOT || v->tile != tile ||
-				(IsFrontEngine(v) && needs_to_be_stopped && !(v->vehstatus & VS_STOPPED))) {
+				(v->IsFrontEngine() && needs_to_be_stopped && !(v->vehstatus & VS_STOPPED))) {
 			return -1;
 		}
 	}
@@ -1033,7 +1032,7 @@ static void NormaliseTrainConsist(Train *v)
 {
 	if (IsFreeWagon(v)) return;
 
-	assert(IsFrontEngine(v));
+	assert(v->IsFrontEngine());
 
 	for (; v != NULL; v = GetNextVehicle(v)) {
 		if (!IsMultiheaded(v) || !IsTrainEngine(v)) continue;
@@ -1136,7 +1135,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 
 			if (src_len + dst_len > max_len) {
 				/* Abort if we're adding too many wagons to a train. */
-				if (dst_head != NULL && IsFrontEngine(dst_head)) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
+				if (dst_head != NULL && dst_head->IsFrontEngine()) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
 				/* Abort if we're making a train on a new row. */
 				if (dst_head == NULL && IsTrainEngine(src)) return_cmd_error(STR_ERROR_TRAIN_TOO_LONG);
 			}
@@ -1148,7 +1147,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 	}
 
 	/* moving a loco to a new line?, then we need to assign a unitnumber. */
-	if (dst == NULL && !IsFrontEngine(src) && IsTrainEngine(src)) {
+	if (dst == NULL && !src->IsFrontEngine() && IsTrainEngine(src)) {
 		UnitID unit_num = ((flags & DC_AUTOREPLACE) != 0 ? 0 : GetFreeUnitNumber(VEH_TRAIN));
 		if (unit_num > _settings_game.vehicle.max_trains)
 			return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
@@ -1157,7 +1156,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 	}
 
 	/* When we move the front vehicle, the second vehicle might need a unitnumber */
-	if (!HasBit(p2, 0) && (IsFreeWagon(src) || (IsFrontEngine(src) && dst == NULL)) && (flags & DC_AUTOREPLACE) == 0) {
+	if (!HasBit(p2, 0) && (IsFreeWagon(src) || (src->IsFrontEngine() && dst == NULL)) && (flags & DC_AUTOREPLACE) == 0) {
 		Vehicle *second = GetNextUnit(src);
 		if (second != NULL && IsTrainEngine(second) && GetFreeUnitNumber(VEH_TRAIN) > _settings_game.vehicle.max_trains) {
 			return_cmd_error(STR_ERROR_TOO_MANY_VEHICLES_IN_GAME);
@@ -1268,7 +1267,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 	if (flags & DC_EXEC) {
 		/* If we move the front Engine and if the second vehicle is not an engine
 		   add the whole vehicle to the DEFAULT_GROUP */
-		if (IsFrontEngine(src) && !IsDefaultGroupID(src->group_id)) {
+		if (src->IsFrontEngine() && !IsDefaultGroupID(src->group_id)) {
 			Vehicle *v = GetNextVehicle(src);
 
 			if (v != NULL && IsTrainEngine(v)) {
@@ -1301,7 +1300,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 
 			/* move the train to an empty line. for locomotives, we set the type to TS_Front. for wagons, 4. */
 			if (IsTrainEngine(src)) {
-				if (!IsFrontEngine(src)) {
+				if (!src->IsFrontEngine()) {
 					/* setting the type to 0 also involves setting up the orders field. */
 					SetFrontEngine(src);
 					assert(src->orders.list == NULL);
@@ -1319,7 +1318,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 			}
 			dst_head = src;
 		} else {
-			if (IsFrontEngine(src)) {
+			if (src->IsFrontEngine()) {
 				/* the vehicle was previously a loco. need to free the order list and delete vehicle windows etc. */
 				DeleteWindowById(WC_VEHICLE_VIEW, src->index);
 				DeleteWindowById(WC_VEHICLE_ORDERS, src->index);
@@ -1330,7 +1329,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 				RemoveVehicleFromGroup(src);
 			}
 
-			if (IsFrontEngine(src) || IsFreeWagon(src)) {
+			if (src->IsFrontEngine() || IsFreeWagon(src)) {
 				InvalidateWindowData(WC_VEHICLE_DEPOT, src->tile);
 				ClearFrontEngine(src);
 				ClearFreeWagon(src);
@@ -1357,7 +1356,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 		/* If there is an engine behind first_engine we moved away, it should become new first_engine
 		 * To do this, CmdMoveRailVehicle must be called once more
 		 * we can't loop forever here because next time we reach this line we will have a front engine */
-		if (src_head != NULL && !IsFrontEngine(src_head) && IsTrainEngine(src_head)) {
+		if (src_head != NULL && !src_head->IsFrontEngine() && IsTrainEngine(src_head)) {
 			/* As in CmdMoveRailVehicle src_head->group_id will be equal to DEFAULT_GROUP
 			 * we need to save the group and reaffect it to src_head */
 			const GroupID tmp_g = src_head->group_id;
@@ -1370,7 +1369,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 			NormaliseTrainConsist(src_head);
 			TrainConsistChanged(src_head, false);
 			UpdateTrainGroupID(src_head);
-			if (IsFrontEngine(src_head)) {
+			if (src_head->IsFrontEngine()) {
 				/* Update the refit button and window */
 				InvalidateWindow(WC_VEHICLE_REFIT, src_head->index);
 				InvalidateWindowWidget(WC_VEHICLE_VIEW, src_head->index, VVW_WIDGET_REFIT_VEH);
@@ -1383,7 +1382,7 @@ CommandCost CmdMoveRailVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, u
 			NormaliseTrainConsist(dst_head);
 			TrainConsistChanged(dst_head, false);
 			UpdateTrainGroupID(dst_head);
-			if (IsFrontEngine(dst_head)) {
+			if (dst_head->IsFrontEngine()) {
 				/* Update the refit button and window */
 				InvalidateWindowWidget(WC_VEHICLE_VIEW, dst_head->index, VVW_WIDGET_REFIT_VEH);
 				InvalidateWindow(WC_VEHICLE_REFIT, dst_head->index);
@@ -1429,7 +1428,7 @@ CommandCost CmdSellRailWagon(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 	if (IsRearDualheaded(v)) return_cmd_error(STR_ERROR_REAR_ENGINE_FOLLOW_FRONT);
 
 	if (flags & DC_EXEC) {
-		if (v == first && IsFrontEngine(first)) {
+		if (v == first && first->IsFrontEngine()) {
 			DeleteWindowById(WC_VEHICLE_VIEW, first->index);
 			DeleteWindowById(WC_VEHICLE_ORDERS, first->index);
 			DeleteWindowById(WC_VEHICLE_REFIT, first->index);
@@ -1512,7 +1511,7 @@ CommandCost CmdSellRailWagon(TileIndex tile, DoCommandFlag flags, uint32 p1, uin
 					NormaliseTrainConsist(first);
 					TrainConsistChanged(first, false);
 					UpdateTrainGroupID(first);
-					if (IsFrontEngine(first)) InvalidateWindow(WC_VEHICLE_REFIT, first->index);
+					if (first->IsFrontEngine()) InvalidateWindow(WC_VEHICLE_REFIT, first->index);
 				}
 
 			}
@@ -1720,14 +1719,16 @@ static Vehicle *TrainOnTileEnum(Vehicle *v, void *)
  */
 static Vehicle *TrainApproachingCrossingEnum(Vehicle *v, void *data)
 {
-	/* not a train || not front engine || crashed */
-	if (v->type != VEH_TRAIN || !IsFrontEngine(v) || (v->vehstatus & VS_CRASHED)) return NULL;
+	if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
 
-	TileIndex tile = *(TileIndex*)data;
+	Train *t = Train::From(v);
+	if (!t->IsFrontEngine()) return NULL;
 
-	if (TrainApproachingCrossingTile(Train::From(v)) != tile) return NULL;
+	TileIndex tile = *(TileIndex *)data;
 
-	return v;
+	if (TrainApproachingCrossingTile(t) != tile) return NULL;
+
+	return t;
 }
 
 
@@ -2512,7 +2513,7 @@ static void ClearPathReservation(const Train *v, TileIndex tile, Trackdir track_
 /** Free the reserved path in front of a vehicle. */
 void FreeTrainTrackReservation(const Train *v, TileIndex origin, Trackdir orig_td)
 {
-	assert(IsFrontEngine(v));
+	assert(v->IsFrontEngine());
 
 	TileIndex tile = origin != INVALID_TILE ? origin : v->tile;
 	Trackdir  td = orig_td != INVALID_TRACKDIR ? orig_td : v->GetVehicleTrackdir();
@@ -3098,7 +3099,7 @@ static Track ChooseTrainTrack(Train *v, TileIndex tile, DiagDirection enterdir,
  */
 bool TryPathReserve(Train *v, bool mark_as_stuck, bool first_tile_okay)
 {
-	assert(v->type == VEH_TRAIN && IsFrontEngine(v));
+	assert(v->IsFrontEngine());
 
 	/* We have to handle depots specially as the track follower won't look
 	 * at the depot tile itself but starts from the next tile. If we are still
@@ -3419,7 +3420,7 @@ static inline bool CheckCompatibleRail(const Train *v, TileIndex tile)
 {
 	return
 		IsTileOwner(tile, v->owner) && (
-			!IsFrontEngine(v) ||
+			!v->IsFrontEngine() ||
 			HasBit(v->compatible_railtypes, GetRailType(tile))
 		);
 }
@@ -3473,7 +3474,7 @@ static void SetVehicleCrashed(Train *v)
 	if (v->crash_anim_pos != 0) return;
 
 	/* Free a possible path reservation and try to mark all tiles occupied by the train reserved. */
-	if (IsFrontEngine(v)) {
+	if (v->IsFrontEngine()) {
 		/* Remove all reservations, also the ones currently under the train
 		 * and any railway station paltform reservation. */
 		FreeTrainTrackReservation(v);
@@ -3631,16 +3632,19 @@ static bool CheckTrainCollision(Train *v)
 	return true;
 }
 
-static Vehicle *CheckVehicleAtSignal(Vehicle *v, void *data)
+static Vehicle *CheckTrainAtSignal(Vehicle *v, void *data)
 {
+	if (v->type != VEH_TRAIN || (v->vehstatus & VS_CRASHED)) return NULL;
+
+	Train *t = Train::From(v);
 	DiagDirection exitdir = *(DiagDirection *)data;
 
-	/* front engine of a train, not inside wormhole or depot, not crashed */
-	if (v->type == VEH_TRAIN && IsFrontEngine(v) && (Train::From(v)->track & TRACK_BIT_MASK) && !(v->vehstatus & VS_CRASHED)) {
-		if (v->cur_speed <= 5 && TrainExitDir(v->direction, Train::From(v)->track) == exitdir) return v;
-	}
+	/* not front engine of a train, inside wormhole or depot, crashed */
+	if (!t->IsFrontEngine() || !(t->track & TRACK_BIT_MASK)) return NULL;
 
-	return NULL;
+	if (t->cur_speed > 5 || TrainExitDir(t->direction, t->track) != exitdir) return NULL;
+
+	return t;
 }
 
 static void TrainController(Train *v, Vehicle *nomove)
@@ -3667,7 +3671,7 @@ static void TrainController(Train *v, Vehicle *nomove)
 					/* Not inside depot */
 
 					/* Reverse when we are at the end of the track already, do not move to the new position */
-					if (IsFrontEngine(v) && !TrainCheckIfLineEnds(v)) return;
+					if (v->IsFrontEngine() && !TrainCheckIfLineEnds(v)) return;
 
 					uint32 r = VehicleEnterTile(v, gp.new_tile, gp.x, gp.y);
 					if (HasBit(r, VETS_CANNOT_ENTER)) {
@@ -3737,7 +3741,7 @@ static void TrainController(Train *v, Vehicle *nomove)
 								exitdir = ReverseDiagDir(exitdir);
 
 								/* check if a train is waiting on the other side */
-								if (!HasVehicleOnPos(o_tile, &exitdir, &CheckVehicleAtSignal)) return;
+								if (!HasVehicleOnPos(o_tile, &exitdir, &CheckTrainAtSignal)) return;
 							}
 						}
 
@@ -3805,7 +3809,7 @@ static void TrainController(Train *v, Vehicle *nomove)
 				if (!HasBit(r, VETS_ENTERED_WORMHOLE)) {
 					Track track = FindFirstTrack(chosen_track);
 					Trackdir tdir = TrackDirectionToTrackdir(track, chosen_dir);
-					if (IsFrontEngine(v) && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
+					if (v->IsFrontEngine() && HasPbsSignalOnTrackdir(gp.new_tile, tdir)) {
 						SetSignalStateByTrackdir(gp.new_tile, tdir, SIGNAL_STATE_RED);
 						MarkTileDirtyByTile(gp.new_tile);
 					}
@@ -3837,7 +3841,7 @@ static void TrainController(Train *v, Vehicle *nomove)
 					v->direction = chosen_dir;
 				}
 
-				if (IsFrontEngine(v)) {
+				if (v->IsFrontEngine()) {
 					v->load_unload_time_rem = 0;
 
 					/* If we are approching a crossing that is reserved, play the sound now. */
@@ -3864,7 +3868,7 @@ static void TrainController(Train *v, Vehicle *nomove)
 
 			if (IsTileType(gp.new_tile, MP_TUNNELBRIDGE) && HasBit(VehicleEnterTile(v, gp.new_tile, gp.x, gp.y), VETS_ENTERED_WORMHOLE)) {
 				/* Perform look-ahead on tunnel exit. */
-				if (IsFrontEngine(v)) {
+				if (v->IsFrontEngine()) {
 					TryReserveRailTrack(gp.new_tile, DiagDirToDiagTrack(GetTunnelBridgeDirection(gp.new_tile)));
 					CheckNextTrainTile(v);
 				}
@@ -3891,7 +3895,7 @@ static void TrainController(Train *v, Vehicle *nomove)
 		}
 
 		if (update_signals_crossing) {
-			if (IsFrontEngine(v)) {
+			if (v->IsFrontEngine()) {
 				if (TrainMovedChangeSignals(gp.new_tile, enterdir)) {
 					/* We are entering a block with PBS signals right now, but
 					 * not through a PBS signal. This means we don't have a
@@ -3918,7 +3922,7 @@ static void TrainController(Train *v, Vehicle *nomove)
 		}
 
 		/* Do not check on every tick to save some computing time. */
-		if (IsFrontEngine(v) && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
+		if (v->IsFrontEngine() && v->tick_counter % _settings_game.pf.path_backoff_interval == 0) CheckNextTrainTile(v);
 	}
 
 	if (direction_changed) first->tcache.cached_max_curve_speed = GetTrainCurveSpeedLimit(first);
@@ -4202,7 +4206,7 @@ static bool TrainCanLeaveTile(const Train *v)
  */
 static TileIndex TrainApproachingCrossingTile(const Train *v)
 {
-	assert(IsFrontEngine(v));
+	assert(v->IsFrontEngine());
 	assert(!(v->vehstatus & VS_CRASHED));
 
 	if (!TrainCanLeaveTile(v)) return INVALID_TILE;
@@ -4447,7 +4451,7 @@ bool Train::Tick()
 
 	this->tick_counter++;
 
-	if (IsFrontEngine(this)) {
+	if (this->IsFrontEngine()) {
 		if (!(this->vehstatus & VS_STOPPED)) this->running_ticks++;
 
 		this->current_order_time++;
@@ -4506,7 +4510,7 @@ void Train::OnNewDay()
 {
 	if ((++this->day_counter & 7) == 0) DecreaseVehicleValue(this);
 
-	if (IsFrontEngine(this)) {
+	if (this->IsFrontEngine()) {
 		CheckVehicleBreakdown(this);
 		AgeVehicle(this);
 
diff --git a/src/train_gui.cpp b/src/train_gui.cpp
index 458b51a43..9f0373065 100644
--- a/src/train_gui.cpp
+++ b/src/train_gui.cpp
@@ -26,7 +26,7 @@ void CcBuildWagon(bool success, TileIndex tile, uint32 p1, uint32 p2)
 	const Vehicle *found = NULL;
 	const Train *t;
 	FOR_ALL_TRAINS(t) {
-		if (IsFrontEngine(t) && t->tile == tile &&
+		if (t->IsFrontEngine() && t->tile == tile &&
 				t->track == TRACK_BIT_DEPOT) {
 			if (found != NULL) return; // must be exactly one.
 			found = t;
diff --git a/src/tunnelbridge_cmd.cpp b/src/tunnelbridge_cmd.cpp
index 0c0f1ca0c..908bb62e6 100644
--- a/src/tunnelbridge_cmd.cpp
+++ b/src/tunnelbridge_cmd.cpp
@@ -1374,7 +1374,7 @@ static VehicleEnterTileStatus VehicleEnter_TunnelBridge(Vehicle *v, TileIndex ti
 			vdir = DirToDiagDir(t->direction);
 
 			if (t->track != TRACK_BIT_WORMHOLE && dir == vdir) {
-				if (IsFrontEngine(t) && fc == _tunnel_fractcoord_1[dir]) {
+				if (t->IsFrontEngine() && fc == _tunnel_fractcoord_1[dir]) {
 					if (!PlayVehicleSound(t, VSE_TUNNEL) && RailVehInfo(t->engine_type)->engclass == 0) {
 						SndPlayVehicleFx(SND_05_TRAIN_THROUGH_TUNNEL, v);
 					}
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index 49f5f2dc5..f982c0fca 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -518,7 +518,7 @@ void Vehicle::PreDestructor()
 		}
 	}
 
-	if (this->type != VEH_TRAIN || (this->type == VEH_TRAIN && (IsFrontEngine(this) || IsFreeWagon(this)))) {
+	if (this->type != VEH_TRAIN || (this->type == VEH_TRAIN && (Train::From(this)->IsFrontEngine() || IsFreeWagon(this)))) {
 		InvalidateWindowData(WC_VEHICLE_DEPOT, this->tile);
 	}
 
@@ -959,18 +959,20 @@ uint8 CalcPercentVehicleFilled(const Vehicle *v, StringID *colour)
 void VehicleEnterDepot(Vehicle *v)
 {
 	switch (v->type) {
-		case VEH_TRAIN:
+		case VEH_TRAIN: {
+			Train *t = Train::From(v);
 			InvalidateWindowClasses(WC_TRAINS_LIST);
 			/* Clear path reservation */
-			SetDepotWaypointReservation(v->tile, false);
-			if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(v->tile);
-
-			if (!IsFrontEngine(v)) v = v->First();
-			UpdateSignalsOnSegment(v->tile, INVALID_DIAGDIR, v->owner);
-			v->load_unload_time_rem = 0;
-			ClrBit(Train::From(v)->flags, VRF_TOGGLE_REVERSE);
-			TrainConsistChanged(Train::From(v), true);
+			SetDepotWaypointReservation(t->tile, false);
+			if (_settings_client.gui.show_track_reservation) MarkTileDirtyByTile(t->tile);
+
+			if (!t->IsFrontEngine()) t = t->First();
+			UpdateSignalsOnSegment(t->tile, INVALID_DIAGDIR, t->owner);
+			t->load_unload_time_rem = 0;
+			ClrBit(t->flags, VRF_TOGGLE_REVERSE);
+			TrainConsistChanged(t, true);
 			break;
+		}
 
 		case VEH_ROAD:
 			InvalidateWindowClasses(WC_ROADVEH_LIST);
diff --git a/src/vehicle_cmd.cpp b/src/vehicle_cmd.cpp
index bd5e92554..071cc170c 100644
--- a/src/vehicle_cmd.cpp
+++ b/src/vehicle_cmd.cpp
@@ -350,7 +350,7 @@ CommandCost CmdCloneVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 
 	if (!CheckOwnership(v->owner)) return CMD_ERROR;
 
-	if (v->type == VEH_TRAIN && (!IsFrontEngine(v) || Train::From(v)->crash_anim_pos >= 4400)) return CMD_ERROR;
+	if (v->type == VEH_TRAIN && (!Train::From(v)->IsFrontEngine() || Train::From(v)->crash_anim_pos >= 4400)) return CMD_ERROR;
 
 	/* check that we can allocate enough vehicles */
 	if (!(flags & DC_EXEC)) {
@@ -386,7 +386,7 @@ CommandCost CmdCloneVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 				SetBit(Train::From(w)->flags, VRF_REVERSE_DIRECTION);
 			}
 
-			if (v->type == VEH_TRAIN && !IsFrontEngine(v)) {
+			if (v->type == VEH_TRAIN && !Train::From(v)->IsFrontEngine()) {
 				/* this s a train car
 				 * add this unit to the end of the train */
 				CommandCost result = DoCommand(0, (w_rear->index << 16) | w->index, 1, flags, CMD_MOVE_RAIL_VEHICLE);
diff --git a/src/water_cmd.cpp b/src/water_cmd.cpp
index a692e53a6..3034f98cd 100644
--- a/src/water_cmd.cpp
+++ b/src/water_cmd.cpp
@@ -798,18 +798,20 @@ static void FloodVehicle(Vehicle *v)
 
 			switch (v->type) {
 				default: NOT_REACHED();
-				case VEH_TRAIN:
-					if (IsFrontEngine(v)) {
+				case VEH_TRAIN: {
+					Train *t = Train::From(v);
+					if (t->IsFrontEngine()) {
 						pass += 4; // driver
 						/* FreeTrainTrackReservation() calls GetVehicleTrackdir() that doesn't like crashed vehicles.
 						 * In this case, v->direction matches v->u.rail.track, so we can do this (it wasn't crashed before) */
-						v->vehstatus &= ~VS_CRASHED;
-						FreeTrainTrackReservation(Train::From(v));
-						v->vehstatus |= VS_CRASHED;
+						t->vehstatus &= ~VS_CRASHED;
+						FreeTrainTrackReservation(t);
+						t->vehstatus |= VS_CRASHED;
 					}
-					Train::From(v)->crash_anim_pos = 4000; // max 4440, disappear pretty fast
+					t->crash_anim_pos = 4000; // max 4440, disappear pretty fast
 					InvalidateWindowClassesData(WC_TRAINS_LIST, 0);
 					break;
+				}
 
 				case VEH_ROAD:
 					if (IsRoadVehFront(v)) pass += 1; // driver