/// <summary>
/// This method is called recursively to generate the level. Given a
/// room that is partially initialized, in that only some of its doors
/// are connected to other rooms, spawn new rooms for the remaining
/// doors that do not have an associated room. It will then call
/// SpawnChildRooms on those new rooms.
/// </summary>
/// <param name="room">
/// The RoomConnectionBehaviour of a partially initialized room.
/// Partially initialized meaning it has some doors that are not yet
/// connected to other rooms.
/// </param>
/// <param name="parent">
/// The transform of the parent gameobject, the instantiated rooms
/// comprising the level will be a child of the given transform.
/// </param>
/// <param name="grid">
/// The RoomGrid to use while constructing the level.
/// </param>
/// <param name="depth">
/// The depth of the level to be generated. Depth should be a value
/// larger than zero. The depth is used to limit the recursion of this
/// method.
/// </param>
/// <param name="disableChildRooms">
/// Whether or not child-rooms (any room that is not the starting room)
/// should be initially disabled. Normally rooms should only be enabled
/// when the player enters them however it is sometimes useful for
/// debugging to have all rooms enabled.
/// </param>
private static void SpawnChildRooms(RoomConnectionBehaviour room, Transform parent, RoomGrid grid, int depth, bool disableChildRooms)
{
bool enclosedPrefabRequired = depth == 1;
bool DoorIsNotConnected(DoorConnectionBehaviour door) => door.ConnectingDoor == null;
Debug.Assert(depth > 0 || room.Doors.Where(DoorIsNotConnected).Count() == 0, "depth reached zero however there are still rooms with unconnected doors.");
foreach (DoorConnectionBehaviour currentDoor in room.Doors.Where(DoorIsNotConnected))
{
// find room prefab
Vector2Int newPosition = room.Position + currentDoor.Direction.ToVector2Int();
GameObject newRoomPrefab = grid.SelectPrefabFor(newPosition, enclosedPrefabRequired, depth);
// create room using prefab
GameObject newRoomInstance = InstanceFactory.InstantiateRoom(newRoomPrefab, parent, newPosition);
RoomConnectionBehaviour newRoom = newRoomInstance.GetComponent <RoomConnectionBehaviour>();
if (disableChildRooms)
{
newRoom.gameObject.SetActive(false);
}
grid.Add(newRoom);
// position room in scene
newRoom.transform.position = new Vector3
{
x = newPosition.x * RoomPlacementOffset.x,
y = newPosition.y * RoomPlacementOffset.y,
z = 0,
};
// recursively spawn child-rooms
SpawnChildRooms(newRoom, parent, grid, depth - 1, disableChildRooms);
}
}
/// <summary>
/// Generate a new randomised level. This is an expensive method and
/// should be called infrequently.
/// </summary>
/// <param name="startingRoomPrefab">
/// A room prefab to use as the starting room.
/// </param>
/// <param name="parent">
/// The transform of the parent gameobject, the instantiated rooms
/// comprising the level will be a child of the given transform.
/// </param>
/// <param name="depth">
/// The depth of the level to be generated. Depth should be a value
/// larger than zero. A larger depth value will result in a larger
/// level being generated.
/// </param>
/// <param name="disableChildRooms">
/// Whether or not child-rooms (any room that is not the starting room)
/// should be initially disabled. Normally rooms should only be enabled
/// when the player enters them however it is sometimes useful for
/// debugging to have all rooms enabled.
/// </param>
/// <returns>
/// Returns the fully instantiated and initialized starting room. All
/// rooms in the level are accessible via the starting room through the
/// connected doors in each room which form a "level graph" of
/// interconnected rooms.
/// </returns>
public static GameObject GenerateLevel(GameObject startingRoomPrefab, Transform parent, int depth, int?seed = null, bool disableChildRooms = true)
{
// NOTE: Due to how level generation is implemented, there is
// always the small possibility that despite best efforts a
// guaranteed room wont be able to find a viable position to spawn
// while upholding all of the required constraints.
//
// To ensure the guaranteed rooms are included in the level, the
// level will re-generate itself if it detects that not all the
// guaranteed rooms were spawned.
// set level generation seed
if (!seed.HasValue)
{
seed = (int)DateTime.Now.Ticks;
}
UnityEngine.Random.InitState(seed.Value);
Log.Info($"Generating level with depth {Log.Cyan(depth)} and seed {Log.Cyan(seed.Value)}", LogCategory.LevelGeneration);
const int attempts = 25;
for (int i = 0; i < attempts; i++)
{
RoomGrid grid = new RoomGrid(depth);
Vector2Int centre = new Vector2Int(0, 0);
GameObject startingRoomInstance = InstanceFactory.InstantiateRoom(startingRoomPrefab, parent, centre);
RoomConnectionBehaviour startingRoom = startingRoomInstance.GetComponent <RoomConnectionBehaviour>();
grid.Add(startingRoom);
SpawnChildRooms(startingRoom, parent, grid, depth, disableChildRooms);
bool levelVerfied = grid.Verify();
if (!levelVerfied)
{
Log.Warning($"Generated level did not pass verification check. Regenerating... (attempt #{i+1})", LogCategory.LevelGeneration);
foreach (Transform childTransform in parent.transform)
{
GameObject.Destroy(childTransform.gameObject);
}
continue;
}
return(startingRoomInstance);
}
throw new Exception("GenerateLevel failed. This is likely due to an invalid SpawnProbability configuration.");
}