(svn r21924) -Codechange: Unify some parts of the articulated vehicle code.

-Cleanup: Avoid conversions to Train and RoadVehicle that are no longer required.

9 files changed, 26 insertions, 56 deletions

diff --git a/src/articulated_vehicles.cpp b/src/articulated_vehicles.cpp
index 824611ddc..ae6b9d5e6 100644
--- a/src/articulated_vehicles.cpp
+++ b/src/articulated_vehicles.cpp
@@ -221,19 +221,7 @@ bool IsArticulatedVehicleCarryingDifferentCargos(const Vehicle *v, CargoID *carg
 			}
 		}
 
-		switch (v->type) {
-			case VEH_TRAIN:
-				v = Train::From(v)->HasArticulatedPart() ? Train::From(v)->GetNextArticulatedPart() : NULL;
-				break;
-
-			case VEH_ROAD:
-				v = RoadVehicle::From(v)->HasArticulatedPart() ? v->Next() : NULL;
-				break;
-
-			default:
-				v = NULL;
-				break;
-		}
+		v = v->HasArticulatedPart() ? v->GetNextArticulatedPart() : NULL;
 	} while (v != NULL);
 
 	if (cargo_type != NULL) *cargo_type = first_cargo;
@@ -268,19 +256,7 @@ void CheckConsistencyOfArticulatedVehicle(const Vehicle *v)
 		assert(v->cargo_type < NUM_CARGO);
 		real_default_capacity[v->cargo_type] += v->cargo_cap;
 
-		switch (v->type) {
-			case VEH_TRAIN:
-				v = Train::From(v)->HasArticulatedPart() ? Train::From(v)->GetNextArticulatedPart() : NULL;
-				break;
-
-			case VEH_ROAD:
-				v = RoadVehicle::From(v)->HasArticulatedPart() ? v->Next() : NULL;
-				break;
-
-			default:
-				v = NULL;
-				break;
-		}
+		v = v->HasArticulatedPart() ? v->GetNextArticulatedPart() : NULL;
 	} while (v != NULL);
 
 	/* Check whether the vehicle carries more cargos than expected */
diff --git a/src/autoreplace_cmd.cpp b/src/autoreplace_cmd.cpp
index 72fa1ffc4..b2360e583 100644
--- a/src/autoreplace_cmd.cpp
+++ b/src/autoreplace_cmd.cpp
@@ -101,18 +101,18 @@ static void TransferCargo(Vehicle *old_veh, Vehicle *new_head, bool part_of_chai
 	assert(!part_of_chain || new_head->IsPrimaryVehicle());
 	/* Loop through source parts */
 	for (Vehicle *src = old_veh; src != NULL; src = src->Next()) {
-		if (!part_of_chain && src->type == VEH_TRAIN && src != old_veh && src != Train::From(old_veh)->other_multiheaded_part && !Train::From(src)->IsArticulatedPart()) {
+		if (!part_of_chain && src->type == VEH_TRAIN && src != old_veh && src != Train::From(old_veh)->other_multiheaded_part && !src->IsArticulatedPart()) {
 			/* Skip vehicles, which do not belong to old_veh */
-			src = Train::From(src)->GetLastEnginePart();
+			src = src->GetLastEnginePart();
 			continue;
 		}
 		if (src->cargo_type >= NUM_CARGO || src->cargo.Count() == 0) continue;
 
 		/* Find free space in the new chain */
 		for (Vehicle *dest = new_head; dest != NULL && src->cargo.Count() > 0; dest = dest->Next()) {
-			if (!part_of_chain && dest->type == VEH_TRAIN && dest != new_head && dest != Train::From(new_head)->other_multiheaded_part && !Train::From(dest)->IsArticulatedPart()) {
+			if (!part_of_chain && dest->type == VEH_TRAIN && dest != new_head && dest != Train::From(new_head)->other_multiheaded_part && !dest->IsArticulatedPart()) {
 				/* Skip vehicles, which do not belong to new_head */
-				dest = Train::From(dest)->GetLastEnginePart();
+				dest = dest->GetLastEnginePart();
 				continue;
 			}
 			if (dest->cargo_type != src->cargo_type) continue;
@@ -218,7 +218,7 @@ static CargoID GetNewCargoTypeForReplace(Vehicle *v, EngineID engine_type, bool
  */
 static EngineID GetNewEngineType(const Vehicle *v, const Company *c)
 {
-	assert(v->type != VEH_TRAIN || !Train::From(v)->IsArticulatedPart());
+	assert(v->type != VEH_TRAIN || !v->IsArticulatedPart());
 
 	if (v->type == VEH_TRAIN && Train::From(v)->IsRearDualheaded()) {
 		/* we build the rear ends of multiheaded trains with the front ones */
diff --git a/src/depot_gui.cpp b/src/depot_gui.cpp
index b057278b1..6d32fd761 100644
--- a/src/depot_gui.cpp
+++ b/src/depot_gui.cpp
@@ -797,7 +797,7 @@ struct DepotWindow : Window {
 				loaded  [w->cargo_type] += w->cargo.Count();
 			}
 
-			if (w->type == VEH_TRAIN && !Train::From(w)->HasArticulatedPart()) {
+			if (w->type == VEH_TRAIN && !w->HasArticulatedPart()) {
 				num++;
 				if (!whole_chain) break;
 			}
@@ -911,7 +911,7 @@ struct DepotWindow : Window {
 						} else if (gdvp.wagon == NULL || gdvp.wagon->index != sel) {
 							this->vehicle_over = INVALID_VEHICLE;
 							TrainDepotMoveVehicle(gdvp.wagon, sel, gdvp.head);
-						} else if (gdvp.head != NULL && Train::From(gdvp.head)->IsFrontEngine()) {
+						} else if (gdvp.head != NULL && gdvp.head->IsFrontEngine()) {
 							ShowVehicleViewWindow(gdvp.head);
 						}
 					}
diff --git a/src/industry_cmd.cpp b/src/industry_cmd.cpp
index 51e623943..84e35181b 100644
--- a/src/industry_cmd.cpp
+++ b/src/industry_cmd.cpp
@@ -2298,7 +2298,7 @@ static 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 && Train::From(v)->IsFrontEngine()) {
+		if (v->type == VEH_TRAIN && 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/roadveh_gui.cpp b/src/roadveh_gui.cpp
index 029234c26..0cbaee06c 100644
--- a/src/roadveh_gui.cpp
+++ b/src/roadveh_gui.cpp
@@ -31,9 +31,7 @@
  */
 void DrawRoadVehDetails(const Vehicle *v, int left, int right, int y)
 {
-	const RoadVehicle *rv = RoadVehicle::From(v);
-
-	uint y_offset = rv->HasArticulatedPart() ? 15 : 0; // Draw the first line below the sprite of an articulated RV instead of after it.
+	uint y_offset = v->HasArticulatedPart() ? 15 : 0; // Draw the first line below the sprite of an articulated RV instead of after it.
 	StringID str;
 	Money feeder_share = 0;
 
@@ -42,7 +40,7 @@ void DrawRoadVehDetails(const Vehicle *v, int left, int right, int y)
 	SetDParam(2, v->value);
 	DrawString(left, right, y + y_offset, STR_VEHICLE_INFO_BUILT_VALUE, TC_FROMSTRING, SA_LEFT | SA_STRIP);
 
-	if (rv->HasArticulatedPart()) {
+	if (v->HasArticulatedPart()) {
 		CargoArray max_cargo;
 		StringID subtype_text[NUM_CARGO];
 		char capacity[512];
diff --git a/src/station_cmd.cpp b/src/station_cmd.cpp
index 68f5c14ef..9d3a0be68 100644
--- a/src/station_cmd.cpp
+++ b/src/station_cmd.cpp
@@ -2953,7 +2953,7 @@ static VehicleEnterTileStatus VehicleEnter_Station(Vehicle *v, TileIndex tile, i
 	if (v->type == VEH_TRAIN) {
 		StationID station_id = GetStationIndex(tile);
 		if (!v->current_order.ShouldStopAtStation(v, station_id)) return VETSB_CONTINUE;
-		if (!IsRailStation(tile) || !Train::From(v)->IsFrontEngine()) return VETSB_CONTINUE;
+		if (!IsRailStation(tile) || !v->IsFrontEngine()) return VETSB_CONTINUE;
 
 		int station_ahead;
 		int station_length;
diff --git a/src/vehicle.cpp b/src/vehicle.cpp
index f69cf03a5..fe5cf1842 100644
--- a/src/vehicle.cpp
+++ b/src/vehicle.cpp
@@ -626,7 +626,7 @@ bool Vehicle::IsEngineCountable() const
 	switch (this->type) {
 		case VEH_AIRCRAFT: return Aircraft::From(this)->IsNormalAircraft(); // don't count plane shadows and helicopter rotors
 		case VEH_TRAIN:
-			return !Train::From(this)->IsArticulatedPart() && // tenders and other articulated parts
+			return !this->IsArticulatedPart() && // tenders and other articulated parts
 					!Train::From(this)->IsRearDualheaded(); // rear parts of multiheaded engines
 		case VEH_ROAD: return RoadVehicle::From(this)->IsFrontEngine();
 		case VEH_SHIP: return true;
@@ -1538,7 +1538,7 @@ LiveryScheme GetEngineLiveryScheme(EngineID engine_type, EngineID parent_engine_
 	switch (e->type) {
 		default: NOT_REACHED();
 		case VEH_TRAIN:
-			if (v != NULL && parent_engine_type != INVALID_ENGINE && (UsesWagonOverride(v) || (Train::From(v)->IsArticulatedPart() && e->u.rail.railveh_type != RAILVEH_WAGON))) {
+			if (v != NULL && parent_engine_type != INVALID_ENGINE && (UsesWagonOverride(v) || (v->IsArticulatedPart() && e->u.rail.railveh_type != RAILVEH_WAGON))) {
 				/* Wagonoverrides use the colour scheme of the front engine.
 				 * Articulated parts use the colour scheme of the first part. (Not supported for articulated wagons) */
 				engine_type = parent_engine_type;
diff --git a/src/vehicle_cmd.cpp b/src/vehicle_cmd.cpp
index fca07e86e..ac3b90eac 100644
--- a/src/vehicle_cmd.cpp
+++ b/src/vehicle_cmd.cpp
@@ -671,7 +671,7 @@ CommandCost CmdCloneVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 	CommandCost ret = CheckOwnership(v->owner);
 	if (ret.Failed()) return ret;
 
-	if (v->type == VEH_TRAIN && (!Train::From(v)->IsFrontEngine() || Train::From(v)->crash_anim_pos >= 4400)) return CMD_ERROR;
+	if (v->type == VEH_TRAIN && (!v->IsFrontEngine() || Train::From(v)->crash_anim_pos >= 4400)) return CMD_ERROR;
 
 	/* check that we can allocate enough vehicles */
 	if (!(flags & DC_EXEC)) {
@@ -719,7 +719,7 @@ CommandCost CmdCloneVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 				SetBit(Train::From(w)->flags, VRF_REVERSE_DIRECTION);
 			}
 
-			if (v->type == VEH_TRAIN && !Train::From(v)->IsFrontEngine()) {
+			if (v->type == VEH_TRAIN && !v->IsFrontEngine()) {
 				/* this s a train car
 				 * add this unit to the end of the train */
 				CommandCost result = DoCommand(0, w->index | 1 << 20, w_rear->index, flags, CMD_MOVE_RAIL_VEHICLE);
@@ -737,7 +737,7 @@ CommandCost CmdCloneVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 			}
 			w_rear = w; // trains needs to know the last car in the train, so they can add more in next loop
 		}
-	} while (v->type == VEH_TRAIN && (v = Train::From(v)->GetNextVehicle()) != NULL);
+	} while (v->type == VEH_TRAIN && (v = v->GetNextVehicle()) != NULL);
 
 	if ((flags & DC_EXEC) && v_front->type == VEH_TRAIN) {
 		/* for trains this needs to be the front engine due to the callback function */
@@ -772,10 +772,8 @@ CommandCost CmdCloneVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 					if (cost.Succeeded()) total_cost.AddCost(cost);
 				}
 
-				if (w->type == VEH_TRAIN && Train::From(w)->HasArticulatedPart()) {
-					w = Train::From(w)->GetNextArticulatedPart();
-				} else if (w->type == VEH_ROAD && RoadVehicle::From(w)->HasArticulatedPart()) {
-					w = w->Next();
+				if (w->IsGroundVehicle() && w->HasArticulatedPart()) {
+					w = w->GetNextArticulatedPart();
 				} else {
 					break;
 				}
@@ -788,17 +786,15 @@ CommandCost CmdCloneVehicle(TileIndex tile, DoCommandFlag flags, uint32 p1, uint
 				}
 			}
 
-			if (v->type == VEH_TRAIN && Train::From(v)->HasArticulatedPart()) {
-				v = Train::From(v)->GetNextArticulatedPart();
-			} else if (v->type == VEH_ROAD && RoadVehicle::From(v)->HasArticulatedPart()) {
-				v = v->Next();
+			if (w->IsGroundVehicle() && w->HasArticulatedPart()) {
+				w = w->GetNextArticulatedPart();
 			} else {
 				break;
 			}
 		} while (v != NULL);
 
-		if ((flags & DC_EXEC) && v->type == VEH_TRAIN) w = Train::From(w)->GetNextVehicle();
-	} while (v->type == VEH_TRAIN && (v = Train::From(v)->GetNextVehicle()) != NULL);
+		if ((flags & DC_EXEC) && v->type == VEH_TRAIN) w = w->GetNextVehicle();
+	} while (v->type == VEH_TRAIN && (v = v->GetNextVehicle()) != NULL);
 
 	if (flags & DC_EXEC) {
 		/*
diff --git a/src/vehicle_gui.cpp b/src/vehicle_gui.cpp
index 9c94fea4b..e16b8deee 100644
--- a/src/vehicle_gui.cpp
+++ b/src/vehicle_gui.cpp
@@ -1785,7 +1785,7 @@ struct VehicleDetailsWindow : Window {
 	uint GetRoadVehDetailsHeight(const Vehicle *v)
 	{
 		uint desired_height;
-		if (RoadVehicle::From(v)->HasArticulatedPart()) {
+		if (v->HasArticulatedPart()) {
 			/* An articulated RV has its text drawn under the sprite instead of after it, hence 15 pixels extra. */
 			desired_height = WD_FRAMERECT_TOP + 15 + 3 * FONT_HEIGHT_NORMAL + 2 + WD_FRAMERECT_BOTTOM;
 			/* Add space for the cargo amount for each part. */
@@ -1962,7 +1962,7 @@ struct VehicleDetailsWindow : Window {
 				uint text_right = r.right - (rtl ? sprite_width : 0);
 
 				/* Articulated road vehicles use a complete line. */
-				if (v->type == VEH_ROAD && RoadVehicle::From(v)->HasArticulatedPart()) {
+				if (v->type == VEH_ROAD && v->HasArticulatedPart()) {
 					DrawVehicleImage(v, r.left + WD_FRAMERECT_LEFT, r.right - WD_FRAMERECT_RIGHT, r.top + WD_FRAMERECT_TOP, INVALID_VEHICLE, 0);
 				} else {
 					uint sprite_left  = rtl ? text_right : r.left;