(svn r3352) - NewGRF: Move initialization of vehicle random_bits to DC_EXEC blocks to allow use of Random() instead of InteractiveRandom(), which will alleviate some possible network desyncs.

aircraft_cmd.c

@@ -265,6 +265,9 @@ int32 CmdBuildAircraft(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 
 		v->cur_image = u->cur_image = 0xEA0;
 
+		v->random_bits = VehicleRandomBits();
+		u->random_bits = VehicleRandomBits();
+
 		VehiclePositionChanged(v);
 		VehiclePositionChanged(u);
 
@@ -286,6 +289,7 @@ int32 CmdBuildAircraft(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 			w->vehstatus = VS_HIDDEN | VS_UNCLICKABLE;
 			w->subtype = 6;
 			w->cur_image = SPR_ROTOR_STOPPED;
+			w->random_bits = VehicleRandomBits();
 			VehiclePositionChanged(w);
 		}
 

roadveh_cmd.c

@@ -187,6 +187,7 @@ int32 CmdBuildRoadVeh(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 
 		v->type = VEH_Road;
 		v->cur_image = 0xC15;
+		v->random_bits = VehicleRandomBits();
 
 		VehiclePositionChanged(v);
 

ship_cmd.c

@@ -888,6 +888,7 @@ int32 CmdBuildShip(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 		v->build_year = _cur_year;
 		v->cur_image = 0x0E5E;
 		v->type = VEH_Ship;
+		v->random_bits = VehicleRandomBits();
 
 		VehiclePositionChanged(v);
 

train_cmd.c

@@ -492,6 +492,7 @@ static void AddArticulatedParts(const RailVehicleInfo *rvi, Vehicle **vl)
 		u->subtype = 0;
 		SetArticulatedPart(u);
 		u->cur_image = 0xAC2;
+		u->random_bits = VehicleRandomBits();
 
 		VehiclePositionChanged(u);
 	}
@@ -572,6 +573,7 @@ static int32 CmdBuildRailWagon(EngineID engine, TileIndex tile, uint32 flags)
 			v->build_year = _cur_year;
 			v->type = VEH_Train;
 			v->cur_image = 0xAC2;
+			v->random_bits = VehicleRandomBits();
 
 			AddArticulatedParts(rvi, vl);
 
@@ -652,6 +654,7 @@ void AddRearEngineToMultiheadedTrain(Vehicle *v, Vehicle *u, bool building)
 	u->value = v->value;
 	u->type = VEH_Train;
 	u->cur_image = 0xAC2;
+	u->random_bits = VehicleRandomBits();
 	VehiclePositionChanged(u);
 }
 
@@ -746,6 +749,7 @@ int32 CmdBuildRailVehicle(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 			v->build_year = _cur_year;
 			v->type = VEH_Train;
 			v->cur_image = 0xAC2;
+			v->random_bits = VehicleRandomBits();
 
 			v->subtype = 0;
 			SetFrontEngine(v);

vehicle.c

@@ -254,16 +254,19 @@ static Vehicle *InitializeVehicle(Vehicle *v)
 	v->next_shared = NULL;
 	v->prev_shared = NULL;
 	v->depot_list  = NULL;
-	/* random_bits is used to pick out a random sprite for vehicles
+	v->random_bits = 0;
-	    which are technical the same (newgrf stuff).
-	   Because RandomRange() results in desyncs, and because it does
-	    not really matter that one client has other visual vehicles than
-	    the other, it can be InteractiveRandomRange() without any problem
-	*/
-	v->random_bits = InteractiveRandomRange(256);
 	return v;
 }
 
+/**
+ * Get a value for a vehicle's random_bits.
+ * @return A random value from 0 to 255.
+ */
+byte VehicleRandomBits(void)
+{
+	return GB(Random(), 0, 8);
+}
+
 Vehicle *ForceAllocateSpecialVehicle(void)
 {
 	/* This stays a strange story.. there should always be room for special

vehicle.h

@@ -271,6 +271,7 @@ void CallVehicleTicks(void);
 Vehicle *FindVehicleOnTileZ(TileIndex tile, byte z);
 
 void InitializeTrains(void);
+byte VehicleRandomBits(void);
 
 bool CanFillVehicle(Vehicle *v);
 bool CanRefitTo(EngineID engine_type, CargoID cid_to);