Fix #6803: CargoMonitorID bit packing updated to handle 64 cargo types.

This requires a saveload bump to change the bitpacking on loading older saves.

3 files changed, 30 insertions, 3 deletions

diff --git a/src/cargomonitor.h b/src/cargomonitor.h
index 061a1821a..e74f717e0 100644
--- a/src/cargomonitor.h
+++ b/src/cargomonitor.h
@@ -45,11 +45,14 @@ enum CargoCompanyBits {
 	CCB_IS_INDUSTRY_BIT        = 16, ///< Bit indicating the town/industry number is an industry.
 	CCB_IS_INDUSTRY_BIT_VALUE  = 1ul << CCB_IS_INDUSTRY_BIT, ///< Value of the #CCB_IS_INDUSTRY_BIT bit.
 	CCB_CARGO_TYPE_START       = 19, ///< Start bit of the cargo type field.
-	CCB_CARGO_TYPE_LENGTH      = 5,  ///< Number of bits of the cargo type field.
-	CCB_COMPANY_START          = 24, ///< Start bit of the company field.
-	CCB_COMPANY_LENGTH         = 8,  ///< Number of bits of the company field.
+	CCB_CARGO_TYPE_LENGTH      = 6,  ///< Number of bits of the cargo type field.
+	CCB_COMPANY_START          = 25, ///< Start bit of the company field.
+	CCB_COMPANY_LENGTH         = 4,  ///< Number of bits of the company field.
 };
 
+assert_compile(NUM_CARGO     <= (1 << CCB_CARGO_TYPE_LENGTH));
+assert_compile(MAX_COMPANIES <= (1 << CCB_COMPANY_LENGTH));
+
 
 /**
  * Encode a cargo monitor for pickup or delivery at an industry.
@@ -61,6 +64,7 @@ enum CargoCompanyBits {
 static inline CargoMonitorID EncodeCargoIndustryMonitor(CompanyID company, CargoID ctype, IndustryID ind)
 {
 	assert(ctype < (1 << CCB_CARGO_TYPE_LENGTH));
+	assert(company < (1 << CCB_COMPANY_LENGTH));
 
 	uint32 ret = 0;
 	SB(ret, CCB_TOWN_IND_NUMBER_START, CCB_TOWN_IND_NUMBER_LENGTH, ind);
@@ -80,6 +84,7 @@ static inline CargoMonitorID EncodeCargoIndustryMonitor(CompanyID company, Cargo
 static inline CargoMonitorID EncodeCargoTownMonitor(CompanyID company, CargoID ctype, TownID town)
 {
 	assert(ctype < (1 << CCB_CARGO_TYPE_LENGTH));
+	assert(company < (1 << CCB_COMPANY_LENGTH));
 
 	uint32 ret = 0;
 	SB(ret, CCB_TOWN_IND_NUMBER_START, CCB_TOWN_IND_NUMBER_LENGTH, town);
diff --git a/src/saveload/cargomonitor_sl.cpp b/src/saveload/cargomonitor_sl.cpp
index 98ad95f09..9a313970f 100644
--- a/src/saveload/cargomonitor_sl.cpp
+++ b/src/saveload/cargomonitor_sl.cpp
@@ -29,6 +29,21 @@ static const SaveLoad _cargomonitor_pair_desc[] = {
 	SLE_END()
 };
 
+static CargoMonitorID FixupCargoMonitor(CargoMonitorID number)
+{
+	/* Between SLV_EXTEND_CARGOTYPES and SLV_FIX_CARGO_MONITOR, the
+	 * CargoMonitorID structure had insufficient packing for more
+	 * than 32 cargo types. Here we have to shuffle bits to account
+	 * for the change.
+	 * Company moved from bits 24-31 to 25-28.
+	 * Cargo type increased from bits 19-23 to 19-24.
+	 */
+	SB(number, 25, 4, GB(number, 24, 4));
+	SB(number, 29, 3, 0);
+	ClrBit(number, 24);
+	return number;
+}
+
 /** Save the #_cargo_deliveries monitoring map. */
 static void SaveDelivery()
 {
@@ -52,12 +67,15 @@ static void SaveDelivery()
 static void LoadDelivery()
 {
 	TempStorage storage;
+	bool fix = IsSavegameVersionBefore(SLV_FIX_CARGO_MONITOR);
 
 	ClearCargoDeliveryMonitoring();
 	for (;;) {
 		if (SlIterateArray() < 0) break;
 		SlObject(&storage, _cargomonitor_pair_desc);
 
+		if (fix) storage.number = FixupCargoMonitor(storage.number);
+
 		std::pair<CargoMonitorID, uint32> p(storage.number, storage.amount);
 		_cargo_deliveries.insert(p);
 	}
@@ -87,12 +105,15 @@ static void SavePickup()
 static void LoadPickup()
 {
 	TempStorage storage;
+	bool fix = IsSavegameVersionBefore(SLV_FIX_CARGO_MONITOR);
 
 	ClearCargoPickupMonitoring();
 	for (;;) {
 		if (SlIterateArray() < 0) break;
 		SlObject(&storage, _cargomonitor_pair_desc);
 
+		if (fix) storage.number = FixupCargoMonitor(storage.number);
+
 		std::pair<CargoMonitorID, uint32> p(storage.number, storage.amount);
 		_cargo_pickups.insert(p);
 	}
diff --git a/src/saveload/saveload.h b/src/saveload/saveload.h
index 5c84abc21..e5e2e1fa2 100644
--- a/src/saveload/saveload.h
+++ b/src/saveload/saveload.h
@@ -290,6 +290,7 @@ enum SaveLoadVersion : uint16 {
 
 	SLV_GROUP_LIVERIES,                     ///< 205  PR#7108 Livery storage change and group liveries.
 	SLV_SHIPS_STOP_IN_LOCKS,                ///< 206  PR#7150 Ship/lock movement changes.
+	SLV_FIX_CARGO_MONITOR,                  ///< 207  PR#7175 Cargo monitor data packing fix to support 64 cargotypes.
 
 	SL_MAX_VERSION,                         ///< Highest possible saveload version
 };