Change: Make ships stop and change direction slowly instead of instantly turning.

src/saveload/saveload.cpp

@@ -273,8 +273,9 @@
  *  201   #6885   Extend NewGRF persistant storages.
  *  202   #6867   Increase industry cargo slots to 16 in, 16 out
  *  203   #7072   Add path cache for ships
+ *  204   #7065   Add extra rotation stages for ships.
  */
-extern const uint16 SAVEGAME_VERSION = 203; ///< Current savegame version of OpenTTD.
+extern const uint16 SAVEGAME_VERSION = 204; ///< Current savegame version of OpenTTD.
 
 SavegameType _savegame_type; ///< type of savegame we are loading
 FileToSaveLoad _file_to_saveload; ///< File to save or load in the openttd loop.

src/saveload/vehicle_sl.cpp

@@ -368,6 +368,14 @@ void AfterLoadVehicles(bool part_of_load)
 				v->SetServiceIntervalIsPercent(c->settings.vehicle.servint_ispercent);
 			}
 		}
+
+		if (IsSavegameVersionBefore(204)) {
+			/* Ship rotation added */
+			Ship *s;
+			FOR_ALL_SHIPS(s) {
+				s->rotation = s->direction;
+			}
+		}
 	}
 
 	CheckValidVehicles();
@@ -753,8 +761,9 @@ const SaveLoad *GetVehicleDescription(VehicleType vt)
 	static const SaveLoad _ship_desc[] = {
 		SLE_WRITEBYTE(Vehicle, type, VEH_SHIP),
 		SLE_VEH_INCLUDE(),
-		      SLE_VAR(Ship, state,     SLE_UINT8),
+		      SLE_VAR(Ship, state,                     SLE_UINT8),
-		SLE_CONDDEQUE(Ship, path,      SLE_UINT8,  203, SL_MAX_VERSION),
+		SLE_CONDDEQUE(Ship, path,                      SLE_UINT8,                  203, SL_MAX_VERSION),
+		  SLE_CONDVAR(Ship, rotation,                  SLE_UINT8,                  204, SL_MAX_VERSION),
 
 		SLE_CONDNULL(16, 2, 143), // old reserved space
 

src/ship.h

@@ -26,8 +26,9 @@ typedef std::deque<TrackdirByte> ShipPathCache;
  * All ships have this type.
  */
 struct Ship FINAL : public SpecializedVehicle<Ship, VEH_SHIP> {
-	TrackBitsByte state; ///< The "track" the ship is following.
+	TrackBitsByte state;    ///< The "track" the ship is following.
-	ShipPathCache path;  ///< Cached path.
+	ShipPathCache path;     ///< Cached path.
+	DirectionByte rotation; ///< Visible direction.
 
 	/** We don't want GCC to zero our struct! It already is zeroed and has an index! */
 	Ship() : SpecializedVehicleBase() {}

src/ship_cmd.cpp

@@ -129,6 +129,8 @@ void Ship::GetImage(Direction direction, EngineImageType image_type, VehicleSpri
 {
 	uint8 spritenum = this->spritenum;
 
+	if (image_type == EIT_ON_MAP) direction = this->rotation;
+
 	if (is_custom_sprite(spritenum)) {
 		GetCustomVehicleSprite(this, direction, image_type, result);
 		if (result->IsValid()) return;
@@ -311,7 +313,7 @@ void Ship::UpdateDeltaXY()
 		{32,  6, -16,  -3}, // NW
 	};
 
-	const int8 *bb = _delta_xy_table[this->direction];
+	const int8 *bb = _delta_xy_table[this->rotation];
 	this->x_offs        = bb[3];
 	this->y_offs        = bb[2];
 	this->x_extent      = bb[1];
@@ -370,10 +372,10 @@ static bool CheckShipLeaveDepot(Ship *v)
 
 	if (north_tracks) {
 		/* Leave towards north */
-		v->direction = DiagDirToDir(north_dir);
+		v->rotation = v->direction = DiagDirToDir(north_dir);
 	} else if (south_tracks) {
 		/* Leave towards south */
-		v->direction = DiagDirToDir(south_dir);
+		v->rotation = v->direction = DiagDirToDir(south_dir);
 	} else {
 		/* Both ways blocked */
 		return false;
@@ -543,7 +545,6 @@ static void ShipController(Ship *v)
 {
 	uint32 r;
 	const byte *b;
-	Direction dir;
 	Track track;
 	TrackBits tracks;
 
@@ -563,6 +564,16 @@ static void ShipController(Ship *v)
 
 	v->ShowVisualEffect();
 
+	/* Rotating on spot */
+	if (v->direction != v->rotation) {
+		if ((v->tick_counter & 7) == 0) {
+			DirDiff diff = DirDifference(v->direction, v->rotation);
+			v->rotation = ChangeDir(v->rotation, diff > DIRDIFF_REVERSE ? DIRDIFF_45LEFT : DIRDIFF_45RIGHT);
+			v->UpdateViewport(true, true);
+		}
+		return;
+	}
+
 	if (!ShipAccelerate(v)) return;
 
 	GetNewVehiclePosResult gp = GetNewVehiclePos(v);
@@ -653,7 +664,22 @@ static void ShipController(Ship *v)
 				if (old_wc != new_wc) v->UpdateCache();
 			}
 
-			v->direction = (Direction)b[2];
+			Direction new_direction = (Direction)b[2];
+			DirDiff diff = DirDifference(new_direction, v->direction);
+			switch (diff) {
+				case DIRDIFF_SAME:
+				case DIRDIFF_45RIGHT:
+				case DIRDIFF_45LEFT:
+					/* Continue at speed */
+					v->rotation = v->direction = new_direction;
+					break;
+
+				default:
+					/* Stop for rotation */
+					v->cur_speed = 0;
+					v->direction = new_direction;
+					break;
+			}
 		}
 	} else {
 		/* On a bridge */
@@ -677,8 +703,8 @@ getout:
 	return;
 
 reverse_direction:
-	dir = ReverseDir(v->direction);
+	v->direction = ReverseDir(v->direction);
-	v->direction = dir;
+	v->cur_speed = 0;
 	v->path.clear();
 	goto getout;
 }