Change: Add variant property to engines.

src/engine.cpp

@@ -73,6 +73,7 @@ Engine::Engine(VehicleType type, EngineID base)
 	this->grf_prop.local_id = base;
 	this->list_position = base;
 	this->preview_company = INVALID_COMPANY;
+	this->display_last_variant = INVALID_ENGINE;
 
 	/* Check if this base engine is within the original engine data range */
 	if (base >= _engine_counts[type]) {
@@ -93,6 +94,8 @@ Engine::Engine(VehicleType type, EngineID base)
 		}
 		/* Set cargo aging period to the default value. */
 		this->info.cargo_age_period = CARGO_AGING_TICKS;
+		/* Not a variant */
+		this->info.variant_id = INVALID_ENGINE;
 		return;
 	}
 

src/engine_base.h

@@ -21,6 +21,15 @@ struct WagonOverride {
 	const SpriteGroup *group;
 };
 
+/** Flags used client-side in the purchase/autorenew engine list. */
+enum class EngineDisplayFlags : byte {
+	None        = 0,         ///< No flag set.
+	HasVariants = (1U << 0), ///< Set if engine has variants.
+	IsFolded    = (1U << 1), ///< Set if display of variants should be folded (hidden).
+	Shaded      = (1U << 2), ///< Set if engine should be masked.
+};
+DECLARE_ENUM_AS_BIT_SET(EngineDisplayFlags)
+
 typedef Pool<Engine, EngineID, 64, 64000> EnginePool;
 extern EnginePool _engine_pool;
 
@@ -45,6 +54,9 @@ struct Engine : EnginePool::PoolItem<&_engine_pool> {
 	uint8 original_image_index; ///< Original vehicle image index, thus the image index of the overridden vehicle
 	VehicleType type;           ///< %Vehicle type, ie #VEH_ROAD, #VEH_TRAIN, etc.
 
+	EngineDisplayFlags display_flags; ///< NOSAVE client-side-only display flags for build engine list.
+	EngineID display_last_variant;    ///< NOSAVE client-side-only last variant selected.
+
 	EngineInfo info;
 
 	union {

src/engine_type.h

@@ -145,6 +145,7 @@ struct EngineInfo {
 	int8 retire_early;  ///< Number of years early to retire vehicle
 	StringID string_id; ///< Default name of engine
 	uint16 cargo_age_period; ///< Number of ticks before carried cargo is aged.
+	EngineID variant_id;     ///< Engine variant ID. If set, will be treated specially in purchase lists.
 };
 
 /**

src/newgrf.cpp

@@ -1334,6 +1334,10 @@ static ChangeInfoResult RailVehicleChangeInfo(uint engine, int numinfo, int prop
 				rvi->curve_speed_mod = buf->ReadWord();
 				break;
 
+			case 0x2F: // Engine variant
+				ei->variant_id = GetNewEngineID(_cur.grffile, VEH_TRAIN, buf->ReadWord());
+				break;
+
 			default:
 				ret = CommonVehicleChangeInfo(ei, prop, buf);
 				break;
@@ -1528,6 +1532,10 @@ static ChangeInfoResult RoadVehicleChangeInfo(uint engine, int numinfo, int prop
 				break;
 			}
 
+			case 0x26: // Engine variant
+				ei->variant_id = GetNewEngineID(_cur.grffile, VEH_ROAD, buf->ReadWord());
+				break;
+
 			default:
 				ret = CommonVehicleChangeInfo(ei, prop, buf);
 				break;
@@ -1700,6 +1708,10 @@ static ChangeInfoResult ShipVehicleChangeInfo(uint engine, int numinfo, int prop
 				break;
 			}
 
+			case 0x20: // Engine variant
+				ei->variant_id = GetNewEngineID(_cur.grffile, VEH_SHIP, buf->ReadWord());
+				break;
+
 			default:
 				ret = CommonVehicleChangeInfo(ei, prop, buf);
 				break;
@@ -1854,6 +1866,10 @@ static ChangeInfoResult AircraftVehicleChangeInfo(uint engine, int numinfo, int
 				avi->max_range = buf->ReadWord();
 				break;
 
+			case 0x20: // Engine variant
+				ei->variant_id = GetNewEngineID(_cur.grffile, VEH_AIRCRAFT, buf->ReadWord());
+				break;
+
 			default:
 				ret = CommonVehicleChangeInfo(ei, prop, buf);
 				break;
@@ -8983,6 +8999,11 @@ static void FinaliseEngineArray()
 
 		if (!HasBit(e->info.climates, _settings_game.game_creation.landscape)) continue;
 
+		/* Set appropriate flags on variant engine */
+		if (e->info.variant_id != INVALID_ENGINE) {
+			Engine::Get(e->info.variant_id)->display_flags |= EngineDisplayFlags::HasVariants;
+		}
+
 		/* Skip wagons, there livery is defined via the engine */
 		if (e->type != VEH_TRAIN || e->u.rail.railveh_type != RAILVEH_WAGON) {
 			LiveryScheme ls = GetEngineLiveryScheme(e->index, INVALID_ENGINE, nullptr);

src/table/engines.h

@@ -24,7 +24,7 @@
  * @param f Bitmask of the climates
  * @note the 5 between b and f is the load amount
  */
-#define MT(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, f, e, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS }
+#define MT(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, f, e, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS, INVALID_ENGINE }
 
 /**
  * Writes the properties of a multiple-unit train into the EngineInfo struct.
@@ -37,7 +37,7 @@
  * @param f Bitmask of the climates
  * @note the 5 between b and f is the load amount
  */
-#define MM(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, f, e, 0, 8, 1 << EF_RAIL_IS_MU, 0, 0, STR_EMPTY, CARGO_AGING_TICKS }
+#define MM(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, f, e, 0, 8, 1 << EF_RAIL_IS_MU, 0, 0, STR_EMPTY, CARGO_AGING_TICKS, INVALID_ENGINE }
 
 /**
  * Writes the properties of a train carriage into the EngineInfo struct.
@@ -50,7 +50,7 @@
  * @see MT
  * @note the 5 between b and f is the load amount
  */
-#define MW(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, f, e, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS }
+#define MW(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, f, e, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS, INVALID_ENGINE }
 
 /**
  * Writes the properties of a road vehicle into the EngineInfo struct.
@@ -63,7 +63,7 @@
  * @param f Bitmask of the climates
  * @note the 5 between b and f is the load amount
  */
-#define MR(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, f, e, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS }
+#define MR(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 5, f, e, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS, INVALID_ENGINE }
 
 /**
  * Writes the properties of a ship into the EngineInfo struct.
@@ -75,7 +75,7 @@
  * @param f Bitmask of the climates
  * @note the 10 between b and f is the load amount
  */
-#define MS(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 10, f, e, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS }
+#define MS(a, b, c, d, e, f) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 10, f, e, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS, INVALID_ENGINE }
 
 /**
  * Writes the properties of an aeroplane into the EngineInfo struct.
@@ -86,7 +86,7 @@
  * @param e Bitmask of the climates
  * @note the 20 between b and e is the load amount
  */
-#define MA(a, b, c, d, e) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 20, e, CT_INVALID, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS }
+#define MA(a, b, c, d, e) { DAYS_TILL_ORIGINAL_BASE_YEAR + a, c, d, b, 20, e, CT_INVALID, 0, 8, 0, 0, 0, STR_EMPTY, CARGO_AGING_TICKS, INVALID_ENGINE }
 
 /* Climates
  * T = Temperate