Assignment4

Assignment 4. CS330 Programming Languages, Summer 2005 (Due Monday July 18)

PLEASE READ CAREFULLY
MISSING DETAILS MAY COST YOU

Details

You might be interviewed regarding your submission.
Make sure you have written everything you
submit. For any function you are trying to write, you can request
what is the desired output for a particular input by email.

Late assignment policy: If the assignment is submitted
within three days from when it was due, you will get half the grade you
would get if you had submitted on time. You will not be able
to submit after three days. (exceptions to this rule only
if you have a VERY important reason).

IMPORTANT: The careful design and documentation (i.e comments) of
your code will be important factors in your grade. If there is a bug
it's better to report it than hide it. Be honest, precise and clear and
you shall be rewarded. NEVER (at least in this class) sacrifice
clarity for efficiency of execution.

(10% of final grade - 10 points)

A multi-user game engine (mugEngine)

In this assignment you will be building a game engine that can
be used to create simple multiplayer text adventure games. The basic
goal is to learn how object oriented programming and C++ can
help you in managing global and local state. Inheritance and container
classes from the STL (Standard Template Libaries) will assist you
in this process.

You will be given code for the server/client communication which you
will need to extend to handle the game management. The type of games
you can create using this engine have the typical structure of
adventure games. There are multiple players (one for each client)
that can move around in a world consisting of rooms/locations.
Various items can be found in each mapsite and players can
pick/drop/examine these items. Each item has an attached value.
You can also talk with other players in the game.

For this assignment you are only required to support movement
between map sites and picking/dropping of items. Various minor details :-)
such as monsters/magic spells/AI controlled players/trading/fighting, graphics 2d or 3d and a purpose/goal for the game can be added for fun but are not required.

On the other hand, an interesting aspect of the game engine is
that you can create new mapsites, new connections between them
and new items while the game is running (only one player called
Builder is allowed to do so).

Here is a sample possible interaction of a client with the game:

> player George

Welcome to the reception hall...
You can see:

 Builder
 George
 A basketball

Available exits:
north
up

Your name is  George

> pick basketball

Welcome to the reception hall...

You can see:

 Builder
 George

Available exits:
north
up

Picked  basketball

> examine George

Welcome to the reception hall...

You can see:

 Builder
 George

Available exits:
north
up

Player  George is carrying:
A basketball : 20

> north
NorthRoom

You can see:
George

Available exits:
west

> drop basketball

NorthRoom

You can see:
George
A basketball

Available exits:
west

Dropped  basketball

> examine basketball

NorthRoom

You can see:
 George
 A basketball

Available exits:
west

Leather basketball: 20

You will also be provided with an executable version of my implementation of the mugEngine which you can use for reference. As usual there might be errors/problems here and there with my implementation as I wrote it quickly during this weekend. I am sure you will find them and let me know :-).

Supported Commands

Words in italics are specified by the user. For example playerName can be George or Tiffany.

player playerName: create a new player (each client can control one and only player)
exitName: goto to the room connected by exitName. ValidexitNames depend on the particular room. Examples could be north, south, teleport, up, down.
pick itemName: the player picks the specified item
drop itemName: the player drops the specified item
examine objectName: returns a longer description of the specified objectNamewhich can be either a player or an item. For items it is their description/value for player it is all the items they are carrying

After any player command is executed the current map site is described together with all the players/items in it as
well as the response for the particular command.

The special player named Builder has the additional ability to create new rooms/items using the following commands:

room roomName : creates a new room - an integer roomId is returned
connect exitName roomId1 roomId2 : creates an exit in the room corresponding to roomId1 connecting it with the room corresponding to roomId2 . Exits are one way so for for "normal" moves you would have to do for example : connect north 0 1 and then connect south 1 0.
item itemName : creates a new item - an integer itemId is returned
describe itemId value description : provides a value and description for a particular item. For example: describe 1 10 shiny crystal ball will associate the description "shiny crystal ball" to the item corresponding to 1 and make it's value equal to 10.

Here are simple commands to add four neighbors to room 0:

room NorthRoom (returns 1)
connect north 0 1
connect south 1 0
room SouthRoom (returns 2)
connect south 0 2
connect north 2 0
etc ...

Suggestions

You are absolutely free to structure the program any way you want. Here are some suggestions you might find helpful. Create a base class GameObject from which Items/Players inherit common functionality and use dynamic binding (virtual functions) for the functions that are specific to each type. Use map<string, GameObject *, less<string> > to create "dictionaries" of items/players/posistions. Create a class MapSite that contains a dictionary of neighbors (pointer to MapSites) and a dictionary of GameObjects. For objects such as MapSites and Items that can not be removed from a game you can also use the vector or list containers of the Standard Template Library. Use a map<int, string, less<int> > as a dictionary to associates clients with particular players. For parsing/printing you will find helpful to use the sstream library for using string like streams.
To include use include<sstream> using namespace std; and use as follows:

ostringstream oss;
oss << "Hello" << x << endl;
string res = oss.str();

and
istringstream iss;
iss.str("Hello 5");
string s;
int v;
iss >> s >> v;

Loading/Saving games

By default the server loads the game stored in file init.txt
and writes the current game to file game.txt. You can
change these names by supplying command line arguments
to the server. For exampel:

mugServer initGame.txt saveGame.txt

That you can create interesting mazes etc and store them as
text files. Notice that the files store the sequence of commands
used to generate the game rather than the game data in some format.

Supporting code

You are going to be provided with skeleton code for a a server, client
program written in C++. The following files will be provided:

Server.cpp
Server.h
Client.cpp
Client.h
Game.h
Game.cpp
Makefile
init.txt (a simple saved game you can use for starters)
mugServerReference (a working executable version used a a reference implementation)

The reference code has been compiled for, and runs fine
on the machines in B215. If you want to use windows you will have
to write your own socket code and your submission must compile
in a B215 machine.

mugEngine.tar.gz

init.txt contains a small initial game setup and you need to
type make to compile the skeleton implementation. To understand how
the program works start the reference server by:

./mugServerRefence

and in another shell window start a client and play with :

./mugClient

then start
./mugServer which is the skeleton code you compiled and
only prints the messages. You will need to extend the code
so that mugServer behaves as mugServerReference.

Deliverables

A game engine that supports the basic commands player and builder commands mentioned above.
The executable implementation can serve as a guide. Please follow the conventions strictly as I might be doing automatic testing on this assignment. IMPORTANT: THE ONLY SIZE ASSUMPTION YOU CAN MAKE IS THAT EACH LINE SENT/RECEIVED BY THE CLIENT/SERVER HAS MAXIMUM SIZE OF 2048 characters. THE NUMBER OF ROOMS/PLAYERS/ITEMS SHOULD NOT
BE FIXED AND CAN BE CHANGED WHILE THE GAME IS RUNING. Any program that makes any such assumption will loose 2 points.

Grading method:

movement commands : 3 points
pick/drop/examine objects : 3 points
builder commands : 3 points
comments/documentation : 1 point

Extra credit

(2pt)
In the late 70s early 80s a group of MIT students created a company called Infocom
and made some really cool text adventure games. The games were written
in an interpreted language called Z-code. There are a number of Z-code interpreter
available on the web. Write code for taking an existing z-code game and
creating a multi-user game out of it using your mugEngine. At minimum
you have to be able to support the same-sites and movement between them
as the z-code game and you also might need to extend the functionality of mugEngine to support other features.

(3pt)
This extra credit is open ended. Any studnet who wants to participate
will implement a full game based on extending the mugEngine.
The two best games will win the 3 extra points. Best will be defined
by voting between all participating students (voting your own students
is not allowed). If only two students participate they get 3pts for free.