Game Programming

About the Obfuscated C Programming Contest

From The Merriam-Webster Collegiate Dictionary:

Main Entry: ob·fus·cate Pronunciation: 'äb-f&-"skAt; äb-'f&s-"kAt, &b- Function: transitive verb Inflected Form(s): -cat·ed; -cat·ing Etymology: Late Latin obfuscatus, past participle of obfuscare, from Latin ob- in the way + fuscus dark brown -- more at OB-, DUSK Date: 1577 1 a : DARKEN    b : to make obscure 2 : CONFUSE - ob·fus·ca·tion /"äb-(")f&s-'kA-sh&n/ noun - ob·fus·ca·to·ry /äb-'f&s-k&-"tOr-E, &b-, -"tor-/ adjective

There's an annual contest for the most illegible, incomprehensible or otherwise most strangely mangled C coding. I entered the source code for Astonia and... no, just kidding. But I thought you might be amused by the weird and wonderful things that can be done with the C language (remember, all the entries are working C programs!), so I'll share this link with you: http://www.ioccc.org/years.html

First the easy part, about compilers:

I list a handful of compilers in this topic:

www.astonia.com/ubb/Forum13/HTML/000004.html

What I referred to then as the "gnu c compiler" now has a very Windows-specific port called "mingw32" or just "mingw". You can read about it (definitely do this first) and download their stuff from "www.mingw.org". The compiler has undergone a few name changes: It used to be called gcc, or "gnu c compiler." Then for a while it was called "egcs" (I've forgotten what that stands for) and now it's called gcc again, but now it stands for "gnu compiler collection" because the same compiler now does C, C++, Fortran, Pascal and possibly something else I've forgotten. gcc is the standard C compiler on all Linux systems, and is the compiler that compiles the server part of Astonia. The "mingw" project brought this compiler to DOS/Windows and added some auxiliary files so it can be used to write Windows programs. This is an open source project, kind of a program by hackers for hackers, so it comes in various bits and pieces you have to find and download. You have to read and understand the documentation that comes with it, and it works best in conjunction with the tools that come with it or alongside it (they're called binutils). I have used this free compiler to compile a truly huge project (not my own code) and it works well. A powerful debugger called gdb comes with this compiler, but it's purely command-line.

A little more convenient package for beginners is the Borland C++ compiler 5.5, which is now available for downloading for free. It is intended ONLY for DOS/Windows and the download is more... in one piece. Lancelot says that the Borland compiler sometimes causes his PC to crash, though. There used to be no debugger with this compiler, but Borland has finally broken down and is offering a debugger along with the compiler. The debugger is full-screen but text-oriented so it looks kind of DOS-like.

These two would be my first recommendations for free C++ capable compilers. I understand there is a package called cygwin which will allow DJGPP to produce Windows executables, but some people consider the DJGPP/cygwin approach a bit awkward because you have to install special runtime libraries for it. The "min" part of Mingw stands for "minimalist" because it's less complicated and generates real, honest Windows-ish executables that run with the standard MSVCRT library.

All 3 compilers are bare-bones command-line compilers. You will need at least an editor with them, and if you're pampered, a complete IDE. There's probably nothing wrong with rhide (I've never used it so I can't say), and you can probably get it to work with all three.

In any case, there's almost no sensible reason for anyone to spend good money on a compiler like M$ Visual C++.

Now for the tougher part, game and graphics programming.

When people show up here and say that they're about to start programming a game like Astonia, I subject them to a lot of public ridicule in the hope of discouraging them. It's not that Astonia is afraid of competition. It's just that what these people are saying sounds to me like, "I've taken my tricycle apart and successfully put it together again. For my next trick, I'm going to design and build an automobile."

Milambeer, you sound a lot more sensible. You're asking about information and where to learn what's required. I'm happy to share some of what I know.

As a first step, for a bit of a challenge, try to do what Corwin is doing: Build a console-mode Tetris. Read the Tetris thread in this forum to get started. Maybe you should collaborate with Corwin? You will find it interesting to write programs that accept keystrokes and respond in realtime. There is a wealth of good games that were written with just characters on an 80 x 25 screen.

When this gets boring, you will want to look at 2D graphics. Windows gives you a set of functions to draw lines, curves and shapes on part of the screen (this is called an API, or Application Programmer Interface). Some people find the Windows API complicated and inconvenient, so there are 2D graphics libraries out there which make some things more convenient. Essentially, 2D graphics is just about drawing the right thing to the right place (x/y) on the screen. This drawing can be either lines and shapes you draw from code, or copying complete graphics images (like the .BMP files used for items and characters in Astonia) to the desired place on the screen. Astonia looks 3D but actually it just copies 2D bitmap images to places on the screen. To make something move (it's called animation), you just draw the screen again without the image you want moved, then draw the image on to the screen in a different place.

The most modern games these days use 3D graphics. 3D graphics involve generating a model, in the program, of what you want the user to see: Walls, floors, objects, characters, lights, and where these things are, and how they're oriented (which direction they're facing in). This information is known as a scene, and the program-internal representation is a scene graph. So you set everything up, including a camera position and orientation (the "eyes" of your user) and then give all this information to a 3D game engine. This is a library of code which computes what the user will see if all the items in the scene are where you say they are, and then draws that scene on to the user's screen. This is called "rendering" a scene.

Whether 2D or 3D, you can only display the graphics you have. You can dig around the Net for graphics other people designed and published, or get some graphics tools (MS Paintbrush as a very modest beginning) and draw your own. If you have some good paper drawings (your own or somebody else's), you could consider scanning them into your computer and then touching them up in a graphics program, rather than starting drawings from scratch on the computer.

If you want your game to be an online, multi-user Internet game like Astonia, then you will need to split it into a "client" part which runs on each user's PC and a "server" part which runs on a PC of yours with a 24/7 Internet connection. If you're just starting and have flat-rate access, you can run the server program on your own PC and leave it connected to the Internet day and night. If you get a lot of players, you may have to move it to a server directly hosted by an ISP. In either case, you'll have to learn about communicating over the Internet, so your client and server can stay coordinated. You'll probably be exchanging messages between client and server either via IP or UDP.

To be decently fast and stable, your server should run Linux rather than Windows. So you're looking at learning a bit about programming for Linux as well as Windows.

All this is quite the adventure. Expect to take years to get anywhere. Depending on how much spare time you have, it's quite possible you will give up after part of the way. This is not as terrible as it sounds: You will have gained a lot of valuable programming experience on the way.

Now for some Internet references to get you started.

These references are excerpted from Game Design, Second Edition, by Marc Saltzmann. I don't have his permission but I'm doing free advertisement for his book, so I feel it's OK. Most of the book quotes some of the industry's greatest game designers on various questions related to their jobs. There's a lot to be learned. I recommend reading this book because, after reading about how tough it is, you will forget about becoming a game designer and save a lot of money on other books about making games. Still... before you read Saltzmann, check out these references:

Computer Role-Playing Game Designer:

www.ultranet.com/~melkior/crpg/index.htm

DevGames.com:

www.devgame.com

GamaSutra:

www.gamasutra.com

Game Design:

members.aol.com/anarchyxi/gamedev.htm

Game Design Newsgroup:

rec.games.design

Game Design @ Gameslice:

www.gameslice.com/vgd/index.shtml

Game Developer Magazine:

www.gdmag.com

Game Development Search Engine:

www.game-developer.com

Gameslice:

www.gameslice.com

GarageGames.com:

www.GarageGames.com

HappyPuppy: The Biz:

happypuppy.com/biz/index.html

I Have No Words and I Must Design:

www.crossover.com/~costik/nowords.html

Loony Games:

www.loonygames.com

Murphy's Rules:

kovalic.com/Murphys/Murphys.html

So, You Want to be a Computer Game Developer:

www.makegames.com

Ultimate Gaming Resource - Company Directory:

www.ugr.net/listings/listings.htm

In addition, a few recommendations from me that I feel he forgot to mention:

Usenet newsgroups such as:

comp.games.development.programming.algorithms and
comp.games.development.programming.misc

If you don't have usenet access set up, you can access newsgroups through

www.dejanews.com

---

Egroups: www.egroups.com

If you don't know what these are, go look. Basically public discussion groups, they're easy to set up (so there are a lot of useless groups) and easy to access, and everything ever posted goes into an archive. Yahoo maintains them for free. I entered "game programming" as a search key and got a list of 72 groups devoted to this topic. Read their archives, and join some of those with a lot of members in them already.

Dr. Dobb's Journal, C/C++ programming resources contains lots of stuff about C and C++. Just one of countless similar pages. I just happen to be a loyal DDJ reader.

Source Forge is a site where people get together to develop open-source software. You may consider joining an already-existing game project (if only to listen in) rather than starting up your own.

Google (or any other search engine):

http://www.google.com/search?q=c%2B%2B+tutorial
Entering "C++ tutorial" as keywords gives you an exhaustive list.

OK, that should be enough material to keep you (and anyone else) browsing for centuries. Enjoy, and if you have any specific questions, please ask!

Milambeer, it depends on what you want to do. LCC32 is a pure C compiler (no C++). C is easier to learn than C++, but maybe you WANT to learn C++. A C++ compiler (and I think DJGPP is one) can also compile C. But DJGPP probably needs (at least) some updates to work with Windows.

Nobody writes DOS programs any more, certainly not DOS games. The moment you write something fairly big, you start messing with memory extenders and boot disks and... I don't even want to think about it. Let's just say that DOS in its original form is dead as far as you are concerned.

Windows GUI, on the other hand, is not easy to program for if you use C and don't have a powerful toolkit like C++ Builder or MSVC++. You need to build your GUI using a resource editor and compiler, then you write coding to make it come alive. It's not pretty. Ishtar hates it and I've only written a toy program or two. I think you'll want to get some practice at C programming before you tackle programming for a Windows GUI.

Fortunately, there is middle ground between pure DOS and Windows GUI: This is Windows Console Mode. You write programs pretty much as you would have for plain old DOS, but you get to use modern compilers and you can use Windows functions. Windows Console programs run in a black window, but have lots of memory and are free of many of the restrictions of "old DOS" programs. This is how Corwin is doing his Tetris game, and this is how I recommend starting game programming in C. You only have text characters for output, but at least it's pretty simple.

Bubble: Tedkees, asked about a function that doesn't echo to the screen. stdin is an istream, not a function, and not only does it echo to the screen but it also requires the user to hit ENTER to end a line. No advantage over scanf().

Tedkees: I don't have a Visual C compiler handy, but the Borland-ish compilers I have have a header file called conio.h containing direct-to-the-console IO stuff. There are functions like kbhit() to test if a key was hit, and getch() to input a character without echoing to the console. Look for "conio.h" to see if your compiler has it, and/or check your compiler's HELP to see if VC has similar functions available.

If you want your program to say Hit any key to continue... then get it to say so, using printf(). That's so simple, there's no function for it. If you want your program to wait for a keystroke after that, use one of the functions Lancelot mentioned. I think getch() is one that doesn't echo.

You can also wimp out and change the message to Hit RETURN to continue and then do a standard getchar() or whatever. A RETURN may move your cursor down but it won't leave any marks on the screen.

RPG Programming

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