Change: Increase max cargo age and let min cargo payment approach zero. (#10596)

Co-authored-by: Michael Lutz <michi@icosahedron.de>

src/cargopacket.cpp

@@ -383,7 +383,7 @@ void VehicleCargoList::AgeCargo()
 	for (ConstIterator it(this->packets.begin()); it != this->packets.end(); it++) {
 		CargoPacket *cp = *it;
 		/* If we're at the maximum, then we can't increase no more. */
-		if (cp->days_in_transit == 0xFF) continue;
+		if (cp->days_in_transit == UINT16_MAX) continue;
 
 		cp->days_in_transit++;
 		this->cargo_days_in_transit += cp->count;

src/cargopacket.h

@@ -44,7 +44,7 @@ struct CargoPacket : CargoPacketPool::PoolItem<&_cargopacket_pool> {
 private:
 	Money feeder_share;     ///< Value of feeder pickup to be paid for on delivery of cargo.
 	uint16 count;           ///< The amount of cargo in this packet.
-	byte days_in_transit;   ///< Amount of days this packet has been in transit.
+	uint16 days_in_transit; ///< Amount of days this packet has been in transit.
 	SourceType source_type; ///< Type of \c source_id.
 	SourceID source_id;     ///< Index of source, INVALID_SOURCE if unknown/invalid.
 	StationID source;       ///< The station where the cargo came from first.
@@ -126,10 +126,10 @@ public:
 	/**
 	 * Gets the number of days this cargo has been in transit.
 	 * This number isn't really in days, but in 2.5 days (CARGO_AGING_TICKS = 185 ticks) and
-	 * it is capped at 255.
+	 * it is capped at UINT16_MAX.
 	 * @return Length this cargo has been in transit.
 	 */
-	inline byte DaysInTransit() const
+	inline uint16 DaysInTransit() const
 	{
 		return this->days_in_transit;
 	}
@@ -221,8 +221,8 @@ public:
 	};
 
 protected:
-	uint count;                 ///< Cache for the number of cargo entities.
+	uint count;                   ///< Cache for the number of cargo entities.
-	uint cargo_days_in_transit; ///< Cache for the sum of number of days in transit of each entity; comparable to man-hours.
+	uint64 cargo_days_in_transit; ///< Cache for the sum of number of days in transit of each entity; comparable to man-hours.
 
 	Tcont packets;              ///< The cargo packets in this list.
 

src/economy.cpp

@@ -975,7 +975,7 @@ Money GetPrice(Price index, uint cost_factor, const GRFFile *grf_file, int shift
 	return cost;
 }
 
-Money GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, CargoID cargo_type)
+Money GetTransportedGoodsIncome(uint num_pieces, uint dist, uint16 transit_days, CargoID cargo_type)
 {
 	const CargoSpec *cs = CargoSpec::Get(cargo_type);
 	if (!cs->IsValid()) {
@@ -985,7 +985,7 @@ Money GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, C
 
 	/* Use callback to calculate cargo profit, if available */
 	if (HasBit(cs->callback_mask, CBM_CARGO_PROFIT_CALC)) {
-		uint32 var18 = std::min(dist, 0xFFFFu) | (std::min(num_pieces, 0xFFu) << 16) | (transit_days << 24);
+		uint32 var18 = std::min(dist, 0xFFFFu) | (std::min(num_pieces, 0xFFu) << 16) | (std::min<uint16>(transit_days, 0xFFu) << 24);
 		uint16 callback = GetCargoCallback(CBID_CARGO_PROFIT_CALC, 0, var18, cs);
 		if (callback != CALLBACK_FAILED) {
 			int result = GB(callback, 0, 14);
@@ -1002,25 +1002,35 @@ Money GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, C
 
 	static const int MIN_TIME_FACTOR = 31;
 	static const int MAX_TIME_FACTOR = 255;
+	static const int TIME_FACTOR_FRAC_BITS = 4;
+	static const int TIME_FACTOR_FRAC = 1 << TIME_FACTOR_FRAC_BITS;
 
 	const int days1 = cs->transit_days[0];
 	const int days2 = cs->transit_days[1];
 	const int days_over_days1 = std::max(   transit_days - days1, 0);
 	const int days_over_days2 = std::max(days_over_days1 - days2, 0);
+	int days_over_max = MIN_TIME_FACTOR - MAX_TIME_FACTOR;
+	if (days2 > -days_over_max) days_over_max += transit_days - days1;
+	else days_over_max += 2 * (transit_days - days1) - days2;
 
 	/*
 	 * The time factor is calculated based on the time it took
 	 * (transit_days) compared two cargo-depending values. The
-	 * range is divided into three parts:
+	 * range is divided into four parts:
 	 *
 	 *  - constant for fast transits
 	 *  - linear decreasing with time with a slope of -1 for medium transports
 	 *  - linear decreasing with time with a slope of -2 for slow transports
+	 *  - after hitting MIN_TIME_FACTOR, the time factor will be asymptotically decreased to a limit of 1 with a scaled 1/(x+1) function.
 	 *
 	 */
-	const int time_factor = std::max(MAX_TIME_FACTOR - days_over_days1 - days_over_days2, MIN_TIME_FACTOR);
+	if (days_over_max > 0) {
-
+		const int time_factor = std::max(2 * MIN_TIME_FACTOR * TIME_FACTOR_FRAC * TIME_FACTOR_FRAC / (days_over_max + 2 * TIME_FACTOR_FRAC), 1); // MIN_TIME_FACTOR / (x/(2 * TIME_FACTOR_FRAC) + 1) + 1, expressed as fixed point with TIME_FACTOR_FRAC_BITS.
-	return BigMulS(dist * time_factor * num_pieces, cs->current_payment, 21);
+		return BigMulS(dist * time_factor * num_pieces, cs->current_payment, 21 + TIME_FACTOR_FRAC_BITS);
+	} else {
+		const int time_factor = std::max(MAX_TIME_FACTOR - days_over_days1 - days_over_days2, MIN_TIME_FACTOR);
+		return BigMulS(dist * time_factor * num_pieces, cs->current_payment, 21);
+	}
 }
 
 /** The industries we've currently brought cargo to. */
@@ -1094,7 +1104,7 @@ static uint DeliverGoodsToIndustry(const Station *st, CargoID cargo_type, uint n
  * @return Revenue for delivering cargo
  * @note The cargo is just added to the stockpile of the industry. It is due to the caller to trigger the industry's production machinery
  */
-static Money DeliverGoods(int num_pieces, CargoID cargo_type, StationID dest, TileIndex source_tile, byte days_in_transit, Company *company, SourceType src_type, SourceID src)
+static Money DeliverGoods(int num_pieces, CargoID cargo_type, StationID dest, TileIndex source_tile, uint16 days_in_transit, Company *company, SourceType src_type, SourceID src)
 {
 	assert(num_pieces > 0);
 

src/economy_func.h

@@ -28,7 +28,7 @@ extern Prices _price;
 int UpdateCompanyRatingAndValue(Company *c, bool update);
 void StartupIndustryDailyChanges(bool init_counter);
 
-Money GetTransportedGoodsIncome(uint num_pieces, uint dist, byte transit_days, CargoID cargo_type);
+Money GetTransportedGoodsIncome(uint num_pieces, uint dist, uint16 transit_days, CargoID cargo_type);
 uint MoveGoodsToStation(CargoID type, uint amount, SourceType source_type, SourceID source_id, const StationList *all_stations, Owner exclusivity = INVALID_OWNER);
 
 void PrepareUnload(Vehicle *front_v);

src/saveload/cargopacket_sl.cpp

@@ -88,14 +88,15 @@
 SaveLoadTable GetCargoPacketDesc()
 {
 	static const SaveLoad _cargopacket_desc[] = {
-		     SLE_VAR(CargoPacket, source,          SLE_UINT16),
+		SLE_VAR(CargoPacket, source,          SLE_UINT16),
-		     SLE_VAR(CargoPacket, source_xy,       SLE_UINT32),
+		SLE_VAR(CargoPacket, source_xy,       SLE_UINT32),
-		     SLE_VAR(CargoPacket, loaded_at_xy,    SLE_UINT32),
+		SLE_VAR(CargoPacket, loaded_at_xy,    SLE_UINT32),
-		     SLE_VAR(CargoPacket, count,           SLE_UINT16),
+		SLE_VAR(CargoPacket, count,           SLE_UINT16),
-		     SLE_VAR(CargoPacket, days_in_transit, SLE_UINT8),
+		SLE_CONDVAR(CargoPacket, days_in_transit, SLE_FILE_U8 | SLE_VAR_U16, SL_MIN_VERSION, SLV_MORE_CARGO_AGE),
-		     SLE_VAR(CargoPacket, feeder_share,    SLE_INT64),
+		SLE_CONDVAR(CargoPacket, days_in_transit, SLE_UINT16, SLV_MORE_CARGO_AGE, SL_MAX_VERSION),
-		 SLE_CONDVAR(CargoPacket, source_type,     SLE_UINT8,  SLV_125, SL_MAX_VERSION),
+		SLE_VAR(CargoPacket, feeder_share,    SLE_INT64),
-		 SLE_CONDVAR(CargoPacket, source_id,       SLE_UINT16, SLV_125, SL_MAX_VERSION),
+		SLE_CONDVAR(CargoPacket, source_type,     SLE_UINT8,  SLV_125, SL_MAX_VERSION),
+		SLE_CONDVAR(CargoPacket, source_id,       SLE_UINT16, SLV_125, SL_MAX_VERSION),
 	};
 	return _cargopacket_desc;
 }

src/saveload/saveload.h

@@ -349,6 +349,7 @@ enum SaveLoadVersion : uint16 {
 
 	SLV_VELOCITY_NAUTICAL,                  ///< 305  PR#10594 Separation of land and nautical velocity (knots!)
 	SLV_CONSISTENT_PARTIAL_Z,               ///< 306  PR#10570 Conversion from an inconsistent partial Z calculation for slopes, to one that is (more) consistent.
+	SLV_MORE_CARGO_AGE,                     ///< 307  PR#10596 Track cargo age for a longer period.
 
 	SL_MAX_VERSION,                         ///< Highest possible saveload version
 };

src/script/api/script_cargo.cpp

@@ -76,7 +76,7 @@
 
 	distance = Clamp<SQInteger>(distance, 0, UINT32_MAX);
 
-	return ::GetTransportedGoodsIncome(1, distance, Clamp(days_in_transit * 2 / 5, 0, 255), cargo_type);
+	return ::GetTransportedGoodsIncome(1, distance, Clamp(days_in_transit * 2 / 5, 0, UINT16_MAX), cargo_type);
 }
 
 /* static */ ScriptCargo::DistributionType ScriptCargo::GetDistributionType(CargoID cargo_type)