(svn r3546) - NewGRF feature: Implement rail vehicle 'property' 0x1A: allows shuffling order of rail vehicle purchase list (and replace vehicle list)

newgrf.c

@@ -365,6 +365,18 @@ static bool RailVehicleChangeInfo(uint engine, int numinfo, int prop, byte **buf
 				rvi[i].engclass = engclass;
 			}
 		} break;
+		case 0x1A: // Alter purchase list sort order.
+			FOR_EACH_OBJECT {
+				EngineID pos = grf_load_byte(&buf);
+
+				if (pos < NUM_TRAIN_ENGINES) {
+					AlterRailVehListOrder(engine + i, pos);
+				} else {
+					grfmsg(GMS_NOTICE, "RailVehicleChangeInfo: Invalid train engine ID %d, ignoring.", pos);
+				}
+			}
+			break;
+
 		case 0x1B: { /* Powered wagons power bonus */
 			FOR_EACH_OBJECT {
 				uint16 wag_power = grf_load_word(&buf);
@@ -431,7 +443,6 @@ static bool RailVehicleChangeInfo(uint engine, int numinfo, int prop, byte **buf
 		} break;
 		/* TODO */
 		/* Fall-through for unimplemented one byte long properties. */
-		case 0x1A:	/* Sort order */
 		case 0x1C:	/* Refit cost */
 		case 0x1F:	/* Tractive effort */
 		case 0x20:	/* Air drag */
@@ -2499,6 +2510,7 @@ static void ResetNewGRFData(void)
 	UnloadWagonOverrides();
 	UnloadCustomEngineSprites();
 	UnloadCustomEngineNames();
+	ResetEngineListOrder();
 
 	// Reset price base data
 	ResetPriceBaseMultipliers();

newgrf_engine.c

@@ -591,3 +591,44 @@ StringID GetCustomEngineName(EngineID engine)
 	return STR_SPEC_USERSTRING;
 }
 
+// Functions for changing the order of vehicle purchase lists
+// This is currently only implemented for rail vehicles.
+static EngineID engine_list_order[NUM_TRAIN_ENGINES];
+
+void ResetEngineListOrder(void)
+{
+	EngineID i;
+
+	for (i = 0; i < NUM_TRAIN_ENGINES; i++)
+		engine_list_order[i] = i;
+}
+
+EngineID GetRailVehAtPosition(EngineID pos)
+{
+	return engine_list_order[pos];
+}
+
+void AlterRailVehListOrder(EngineID engine, EngineID target)
+{
+	EngineID i;
+	bool moving = false;
+
+	if (engine == target) return;
+
+	// First, remove our ID from the list.
+	for (i = 0; i < NUM_TRAIN_ENGINES - 1; i++) {
+		if (engine_list_order[i] == engine)
+			moving = true;
+		if (moving)
+			engine_list_order[i] = engine_list_order[i + 1];
+	}
+
+	// Now, insert it again, before the target engine.
+	for (i = NUM_TRAIN_ENGINES - 1; i > 0; i--) {
+		engine_list_order[i] = engine_list_order[i - 1];
+		if (engine_list_order[i] == target) {
+			engine_list_order[i - 1] = engine;
+			break;
+		}
+	}
+}

newgrf_engine.h

@@ -70,4 +70,8 @@ void UnloadWagonOverrides(void);
 void UnloadCustomEngineSprites(void);
 void UnloadCustomEngineNames(void);
 
+void ResetEngineListOrder(void);
+EngineID GetRailVehAtPosition(EngineID pos);
+void AlterRailVehListOrder(EngineID engine, EngineID target);
+
 #endif /* NEWGRF_ENGINE_H */

train_gui.c

@@ -170,9 +170,10 @@ void CcCloneTrain(bool success, uint tile, uint32 p1, uint32 p2)
 static void engine_drawing_loop(int *x, int *y, int *pos, int *sel,
 	EngineID* selected_id, RailType railtype, byte show_max, bool is_engine)
 {
-	EngineID i;
+	EngineID j;
 
-	for (i = 0; i < NUM_TRAIN_ENGINES; i++) {
+	for (j = 0; j < NUM_TRAIN_ENGINES; j++) {
+		EngineID i = GetRailVehAtPosition(j);
 		const Engine *e = GetEngine(i);
 		const RailVehicleInfo *rvi = RailVehInfo(i);
 

vehicle_gui.c

@@ -453,11 +453,12 @@ static int CDECL VehicleValueSorter(const void *a, const void *b)
 static void train_engine_drawing_loop(int *x, int *y, int *pos, int *sel, EngineID *selected_id, RailType railtype,
 	uint8 lines_drawn, bool is_engine, bool show_cars, bool show_outdated)
 {
-	EngineID i;
+	EngineID j;
 	byte colour;
 	const Player *p = GetPlayer(_local_player);
 
-	for (i = 0; i < NUM_TRAIN_ENGINES; i++) {
+	for (j = 0; j < NUM_TRAIN_ENGINES; j++) {
+		EngineID i = GetRailVehAtPosition(j);
 		const Engine *e = GetEngine(i);
 		const RailVehicleInfo *rvi = RailVehInfo(i);
 		const EngineInfo *info = &_engine_info[i];
@@ -467,7 +468,7 @@ static void train_engine_drawing_loop(int *x, int *y, int *pos, int *sel, Engine
 		if ((rvi->power == 0 && !show_cars) || (rvi->power != 0 && show_cars))  // show wagons or engines (works since wagons do not have power)
 			continue;
 
-		if (*sel == 0) *selected_id = i;
+		if (*sel == 0) *selected_id = j;
 
 
 		colour = *sel == 0 ? 0xC : 0x10;
@@ -513,10 +514,12 @@ static void SetupScrollStuffForReplaceWindow(Window *w)
 
 	switch (WP(w,replaceveh_d).vehicletype) {
 		case VEH_Train: {
+			EngineID i;
 			railtype = _railtype_selected_in_replace_gui;
 			w->widget[13].color = _player_colors[_local_player];	// sets the colour of that art thing
 			w->widget[16].color = _player_colors[_local_player];	// sets the colour of that art thing
-			for (engine_id = 0; engine_id < NUM_TRAIN_ENGINES; engine_id++) {
+			for (i = 0; i < NUM_TRAIN_ENGINES; i++) {
+				EngineID engine_id = GetRailVehAtPosition(i);
 				const Engine *e = GetEngine(engine_id);
 				const EngineInfo *info = &_engine_info[engine_id];