Thread: Map System for Text Based RPG

What you have looks workable, although List<Enemies> probably should be List<Enemy>, and might even be List<unique_ptr<Enemy>> if you're trying to do some fancy OO design for a hierarchy of enemies (but I'm not saying you should: if you don't need it, don't do it).

If you want to represent the rooms such that adjacent rooms are always accessible from each other, then certainly creating a grid would be a good idea. On the other hand, it could be that just because rooms are conceptually adjacent doesn't mean that they can be accessed from each other, or maybe it is possible to enter a room and find that you cannot return to the room from which you came. In that case, a list of exits per room would be better.

Originally Posted by lucas_cage

When I attempt to initialize a DungeonMap and fill it with rooms I am not sure how that part will work.

If you were storing pointers to rooms as the exits, then yes, that might be a little tricky because you might need a two-pass solution: first create the room objects, then create the exits with pointers to the room objects. But here you have assigned unique string identifiers to each room, so all you need to do is to map the identifiers to the room objects, and then store the identifiers as the exit values. You might even create a file (e.g., using JSON, YAML, TOML, etc) to represent the room data in human-readable form, then parse that file to generate the dungeon map.

Originally Posted by lucas_cage

Hello Guys,

I am attempting to develop a map system for text based rpg I am working. I am wondering if anyone here might have some thoughts on how to implement it.

I was thinking of having a class called rooms that was similar to the below.

Code:

enum EXIT_DIRECTION { NORTH, SOUTH...}

Rooms
----------------------------------------------------------
string _roomID (uniqueIdentifier or hash of desc)
string _roomDesc ( a description of the room)
List<Enemies> _enemies (a list of the enemies in the room)
Inventory _roomInventory (a list of items in the room )
Map<exitDirection, roomID> _exits ( a map exit directions of connecting rooms )

Then I would have a DungeonMap class that would have a list of rooms and functions to allow the movement between rooms based on the presence of an exit from the current room. It would basically work like a tree structure that the player can traverse.

Am I on the right path here or does this problem need a different type of solution.

Lucas cage

You seem to have taken the decision that your rooms are constrained to have exits to the north, south, east and west, and it's not possible to have a room with two north-facing exits, for example.

So you need to take a further decision, are your rooms constrained to lie on a grid? Are they all of the same dimensions in layout space, and do they exclude each other?

There's no right answer to this. If you don't make this requirement, then you are logically a bit more consistent. For example a cupboard within a bed chamber could be a "room". Wth the constraint on, the cupboard has to occupy a grid sqaure adjacent to the bedchamber. However, applying the constrain will simplify your design. You can hold the world in a 2d array, you can plot it out with pencil and paper. The layout space doesn't have to match story space, you can still have "a tiny cupboard" as one of your rooms.

If you go for the constraint, then your natural data structure is a 2D array, with connections between the adjacent blacks stored. You might say that all connections are bidirectional but it's probably better to allow for unidirectional connections (e.g. a chute). So just 4 bits per square indicating whether there is a connection to the adjacent squares.

If you don't go for the constraint, you have a graph, with up to four edges between nodes. The graph doesn't have to make any topological sense, so you could have things like car journeys coded in there between very distant nodes in story space. So you need a text file as input giving identifiers for all the rooms and connectiosn between them - you'll have to load it in with two passes to get the rooms, and then match up the identifiers.

Originally Posted by lucas_cage

static int roomID (increment when a room object is created)

Maybe nextID would be a better name?

Originally Posted by lucas_cage

int _roomID
inventory *_roomInventory //inventory object that holds item objects that are in the room
std::string _roomDescription // the details the player can read when entering the rooms

I feel that given that these are member variables of a room class, prefixing them with "room" would just be "stutter", i.e., unnecessary repetition, e.g., you'll end up writing room._roomDescription instead of just room._description. (Having said that, I think a member variable named _ID will violate reserved name rules restricting names that begin with an underscore followed by an uppercase letter, but there's the argument that such name decoration is unnecessary, or it could be a suffix instead.)

Originally Posted by lucas_cage

At this point I don't know that a class to define the whole dungeon is even needed.

It might not be needed, but it might still be useful as an abstraction, e.g., if you want to pass around the entire dungeon to a function by reference.

Originally Posted by Malcolm McLean

You seem to have taken the decision that your rooms are constrained to have exits to the north, south, east and west, and it's not possible to have a room with two north-facing exits, for example.

So you need to take a further decision, are your rooms constrained to lie on a grid? Are they all of the same dimensions in layout space, and do they exclude each other?

There's no right answer to this. If you don't make this requirement, then you are logically a bit more consistent. For example a cupboard within a bed chamber could be a "room". Wth the constraint on, the cupboard has to occupy a grid sqaure adjacent to the bedchamber. However, applying the constrain will simplify your design. You can hold the world in a 2d array, you can plot it out with pencil and paper. The layout space doesn't have to match story space, you can still have "a tiny cupboard" as one of your rooms.

If you go for the constraint, then your natural data structure is a 2D array, with connections between the adjacent blacks stored. You might say that all connections are bidirectional but it's probably better to allow for unidirectional connections (e.g. a chute). So just 4 bits per square indicating whether there is a connection to the adjacent squares.

If you don't go for the constraint, you have a graph, with up to four edges between nodes. The graph doesn't have to make any topological sense, so you could have things like car journeys coded in there between very distant nodes in story space. So you need a text file as input giving identifiers for all the rooms and connectiosn between them - you'll have to load it in with two passes to get the rooms, and then match up the identifiers.

thanks,I find this interesting,trying to make a dungeon,tiles based on 2d text arrays
I also want functionality I seen in games,for example a town above ground should be possible to have a nodes to the different buildings you can go in and out and inside buildings,secret passages between buildings,so read in lots of 2D data and store in 3d array(x,y,level)?

Most Commonly Maps are stored arrays...

Code:

map = [
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  0, 0, 0, 0, 0, 0, 0, 0, 0, 0
];

I have used JSON and XML for levels in HTML5.
It can be more efficient and much more capable.

Originally Posted by christop

How would a map like that have, for example, a room at (1,2) with an exit to the south that leads to the room at (7,8)? How would it name each room or list the inventory in each room?

create room class and other classes and simple fill in the map with pointers to array of room structs,readin data from a database or textfiles
room(1,2).south=room(7,8);

Originally Posted by I C everything

create room class and other classes and simple fill in the map with pointers to array of room structs,readin data from a database or textfiles
room(1,2).south=room(7,8);

If you're doing that, then you're no longer working with an array with the given representation. Refer to the earlier posts for more information.