Cache whether a train may have a depot or bridge speed restriction

src/rail_cmd.cpp

@@ -3582,10 +3582,13 @@ static VehicleEnterTileStatus VehicleEnter_Track(Vehicle *u, TileIndex tile, int
 		if (DiagDirToDir(ReverseDiagDir(dir)) == v->direction) {
 			/* enter the depot */
 
-			if (v->IsFrontEngine() && v->current_order.IsType(OT_LOADING_ADVANCE)) {
-				abort_load_through(true);
-			} else if (v->IsFrontEngine() && HasBit(v->flags, VRF_BEYOND_PLATFORM_END)) {
-				abort_load_through(false);
+			if (v->IsFrontEngine()) {
+				if (v->current_order.IsType(OT_LOADING_ADVANCE)) {
+					abort_load_through(true);
+				} else if (HasBit(v->flags, VRF_BEYOND_PLATFORM_END)) {
+					abort_load_through(false);
+				}
+				SetBit(v->flags, VRF_CONSIST_SPEED_REDUCTION);
 			}
 
 			v->track = TRACK_BIT_DEPOT,

src/saveload/afterload.cpp

@@ -3588,6 +3588,15 @@ bool AfterLoadGame()
 		}
 	}
 
+	if (SlXvIsFeatureMissing(XSLFI_CONSIST_SPEED_RD_FLAG)) {
+		Train *t;
+		FOR_ALL_TRAINS(t) {
+			if ((t->track & TRACK_BIT_WORMHOLE && !(t->vehstatus & VS_HIDDEN)) || t->track == TRACK_BIT_DEPOT) {
+				SetBit(t->First()->flags, VRF_CONSIST_SPEED_REDUCTION);
+			}
+		}
+	}
+
 	/* Road stops is 'only' updating some caches */
 	AfterLoadRoadStops();
 	AfterLoadLabelMaps();

src/saveload/extended_ver_sl.cpp

@@ -92,6 +92,7 @@ const SlxiSubChunkInfo _sl_xv_sub_chunk_infos[] = {
 	{ XSLFI_SELL_AT_DEPOT_ORDER,    XSCF_NULL,                1,   1, "sell_at_depot_order",       NULL, NULL, NULL        },
 	{ XSLFI_BUY_LAND_RATE_LIMIT,    XSCF_NULL,                1,   1, "buy_land_rate_limit",       NULL, NULL, NULL        },
 	{ XSLFI_DUAL_RAIL_TYPES,        XSCF_NULL,                1,   1, "dual_rail_types",           NULL, NULL, NULL        },
+	{ XSLFI_CONSIST_SPEED_RD_FLAG,  XSCF_NULL,                1,   1, "consist_speed_rd_flag",     NULL, NULL, NULL        },
 	{ XSLFI_NULL, XSCF_NULL, 0, 0, NULL, NULL, NULL, NULL },// This is the end marker
 };
 

src/saveload/extended_ver_sl.h

@@ -66,6 +66,7 @@ enum SlXvFeatureIndex {
 	XSLFI_SELL_AT_DEPOT_ORDER,                    ///< Sell vehicle on arrival at depot orders
 	XSLFI_BUY_LAND_RATE_LIMIT,                    ///< Buy land rate limit
 	XSLFI_DUAL_RAIL_TYPES,                        ///< Two rail-types per tile
+	XSLFI_CONSIST_SPEED_RD_FLAG,                  ///< Consist speed reduction flag
 
 	XSLFI_RIFF_HEADER_60_BIT,                     ///< Size field in RIFF chunk header is 60 bit
 	XSLFI_HEIGHT_8_BIT,                           ///< Map tile height is 8 bit instead of 4 bit, but savegame version may be before this became true in trunk

src/train.h

@@ -45,6 +45,7 @@ enum VehicleRailFlags {
 	VRF_NOT_YET_IN_PLATFORM           = 17,
 	VRF_ADVANCE_IN_PLATFORM           = 18,
 	VRF_CONSIST_BREAKDOWN             = 19,///< one or more vehicles in this consist have a breakdown of some sort (breakdown_ctr != 0)
+	VRF_CONSIST_SPEED_REDUCTION       = 20,///< one or more vehicles in this consist may be in a depot or on a bridge (may be false positive but not false negative)
 
 	VRF_IS_BROKEN = (1 << VRF_BREAKDOWN_POWER) | (1 << VRF_BREAKDOWN_SPEED) | (1 << VRF_BREAKDOWN_STOPPED), ///< Bitmask of all flags that indicate a broken train (braking is not included)
 };

src/train_cmd.cpp

@@ -591,15 +591,22 @@ int Train::GetCurrentMaxSpeed() const
 		}
 	}
 
-	for (const Train *u = this; u != NULL; u = u->Next()) {
-		if (_settings_game.vehicle.train_acceleration_model == AM_REALISTIC && u->track == TRACK_BIT_DEPOT) {
-			max_speed = min(max_speed, 61);
-			break;
-		}
+	if (HasBit(this->flags, VRF_CONSIST_SPEED_REDUCTION)) {
+		ClrBit(const_cast<Train *>(this)->flags, VRF_CONSIST_SPEED_REDUCTION);
+		for (const Train *u = this; u != NULL; u = u->Next()) {
+			if (u->track == TRACK_BIT_DEPOT) {
+				SetBit(const_cast<Train *>(this)->flags, VRF_CONSIST_SPEED_REDUCTION);
+				if (_settings_game.vehicle.train_acceleration_model == AM_REALISTIC) {
+					max_speed = min(max_speed, 61);
+				}
+				continue;
+			}
 
-		/* Vehicle is on the middle part of a bridge. */
-		if (u->track & TRACK_BIT_WORMHOLE && !(u->vehstatus & VS_HIDDEN)) {
-			max_speed = min(max_speed, GetBridgeSpec(GetBridgeType(u->tile))->speed);
+			/* Vehicle is on the middle part of a bridge. */
+			if (u->track & TRACK_BIT_WORMHOLE && !(u->vehstatus & VS_HIDDEN)) {
+				SetBit(const_cast<Train *>(this)->flags, VRF_CONSIST_SPEED_REDUCTION);
+				max_speed = min(max_speed, GetBridgeSpec(GetBridgeType(u->tile))->speed);
+			}
 		}
 	}
 
@@ -945,6 +952,7 @@ CommandCost CmdBuildRailVehicle(TileIndex tile, DoCommandFlag flags, const Engin
 		v->y_pos = y;
 		v->z_pos = GetSlopePixelZ(x, y);
 		v->track = TRACK_BIT_DEPOT;
+		SetBit(v->flags, VRF_CONSIST_SPEED_REDUCTION);
 		v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
 		v->spritenum = rvi->image_index;
 		v->cargo_type = e->GetDefaultCargoType();
@@ -5167,6 +5175,7 @@ Train* CmdBuildVirtualRailWagon(const Engine *e)
 
 	v->owner = _current_company;
 	v->track = TRACK_BIT_DEPOT;
+	SetBit(v->flags, VRF_CONSIST_SPEED_REDUCTION);
 	v->vehstatus = VS_HIDDEN | VS_DEFPAL;
 
 	v->SetWagon();
@@ -5238,6 +5247,7 @@ Train* CmdBuildVirtualRailVehicle(EngineID eid, bool lax_engine_check, StringID
 	v->tile = 0; // INVALID_TILE;
 	v->owner = _current_company;
 	v->track = TRACK_BIT_DEPOT;
+	SetBit(v->flags, VRF_CONSIST_SPEED_REDUCTION);
 	v->vehstatus = VS_HIDDEN | VS_STOPPED | VS_DEFPAL;
 	v->spritenum = rvi->image_index;
 	v->cargo_type = e->GetDefaultCargoType();

src/tunnelbridge_cmd.cpp

@@ -2470,6 +2470,7 @@ static VehicleEnterTileStatus VehicleEnter_TunnelBridge(Vehicle *v, TileIndex ti
 					if (frame != TILE_SIZE) return VETSB_CONTINUE;
 					Train *t = Train::From(v);
 					t->track = TRACK_BIT_WORMHOLE;
+					SetBit(t->First()->flags, VRF_CONSIST_SPEED_REDUCTION);
 					ClrBit(t->gv_flags, GVF_GOINGUP_BIT);
 					ClrBit(t->gv_flags, GVF_GOINGDOWN_BIT);
 					break;
@@ -2557,6 +2558,7 @@ static VehicleEnterTileStatus VehicleEnter_TunnelBridge(Vehicle *v, TileIndex ti
 					t->direction = bridge_dir;
 					t->track = TRACK_BIT_WORMHOLE;
 				}
+				SetBit(t->First()->flags, VRF_CONSIST_SPEED_REDUCTION);
 				ClrBit(t->gv_flags, GVF_GOINGUP_BIT);
 				ClrBit(t->gv_flags, GVF_GOINGDOWN_BIT);
 				return VETSB_ENTERED_WORMHOLE;