C/C++ Programing

If you scan through OpenGL.org, you might be able to find an article that was written about 6mo. ago about what and what is not supported by the minigl's. Most minigl's supported a good size set of the opengl library, but not all.

Of note, it might be a good idea to point out that you only need to remove 1 parameter (varies from function to function) from Direct3D to convert from C to C++. Also, don't forget that you can mix the two more often than not as not all functions can be contained in a single class or warrent the use of a single class. Go hybrid, just document as you go along.

I had some major rejections to C++ as the projects that I had in college hardly warrented the use of C++. I could always find a better way to do it in C. However this year I picked up on the positive side of C++ and have been poking around with it since. The easy part is coding, the hard part is planning on how to code it.

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I'll start w/something easy...I was thinking of doing something like the MS "maze" screen saver...scripted movement, basic textures, simple lighting...seems simple enough...(gulp)...

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That shouldn't be too difficult for you as long as you understand some basic data structures. Matricies are common in graphic, and you also need a grasp on normal vectors to get lighting to look right, but your Algebra and Trig should have given you that.

Also, if your really serious, get the OpenGL Programming Guide. It's a very good book, and much more like a textbook than a typical language reference, with programming examples and explanations of almost everything in the libraries. I think the latest version is has a red cover and a picture of a 3D rendered scene with globe made out of Legos.

Also, I should add that the Mesa Graphics Library, available from www.mesa3d.org is a very good OpenGL clone, and not overly hard to get to work if you don't mind playing with it for a while, and I haven't tried anything in it that wasn't supported. It supports a lot more of the language than the miniGL drivers, so you may want to look into that.

Good Luck!

[This message has been edited by Sketch (edited October 12, 2000).]

[This message has been edited by Sketch (edited October 12, 2000).]

Thanks again for the support, especially references and links; I am learning quite a lot from these.

I have been reading 3D Graphics Programing: Games and Beyond (get back w/author) and have found the explanations of the math mostly satisfactory. I can follow the algorithms (very enlightening) but don't entirely understand why the matricies contain the values they do. The translation transformation matrix isn't too bad but for some of the rotation and scaling stuff, the author expands the matricies to 4x4 and fills them with what appears to be gobbledy-gook...

I agree, coding is easy compared to algorithm design. Designing is easy compared to sitting down w/a blank piece of paper and a flowchart stencil...sigh...

Cheers,

-James

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Originally posted by Wintermute:
I agree, coding is easy compared to algorithm design. Designing is easy compared to sitting down w/a blank piece of paper and a flowchart stencil...sigh...

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James;

If you find algorithm design a pain you might want to look at patterns... it makes the design of algorithms much easier. Any kind of algorithms, not just computer ones. Infact its a whole philsophy. Check out design patterns with your favorite search engine. I can tell you its made my life easier as a Java programmer, but its not just for java. Check it out.



[This message has been edited by 100%TotallyNude (edited October 15, 2000).]

James, have you ever checked out gamedev.net?
Lots of useful info for game development. Plus, look in the Code Vault for the downloadable source code for DOOM, the original Quake, Heretic, Hexen, 3D FPS, and Wolfenstein 3D.

[This message has been edited by JabberJaw (edited October 15, 2000).]

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Originally posted by Klashe:
automatically do it for you. The more user friendly a language is (Java, VB) the more translation is needed from the compiler, which equal longer compile/load times.

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What about a large C++ program with a lot of header files, macros and stuff which forces the compiler to make multiple passes over the source code?

Compared with a language such as Object Pascal, most other languages pales in comparison. Borland Delphi is a single pass compiler which produces fairly good machine code (strong on string and integer stuff, not so good with fpu optimizations). Interestingly enough, it compiles very complex applications in seconds, whereas something comparable written in C++ would require minutes to compile unless you have the best iron Sun can throw at you (and the end result wouldn't necessarily be better).

In short: Delphi gives you the power of C++ while not being more difficult to master than VB.

There are two books about Delphi that is worth a read (on this subject), one covers OpenGL and the other specifically deals with game programming.

Another interesting point is that Delphi for Linux is in the works. I doubt we'll see MS VB or VC++ for Linux any time soon.

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Rune

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Originally posted by Wintermute:
I can follow the algorithms (very enlightening) but don't entirely understand why the matricies contain the values they do. The translation transformation matrix isn't too bad but for some of the rotation and scaling stuff, the author expands the matricies to 4x4 and fills them with what appears to be gobbledy-gook...

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It took me a while to see that too. A little background in Linear Algebra helps out a whole lot. I would recommend class, as that's how I learned what little I know, but it was a graduate level (500 level) university course and I realize a lot of hobbyists don't have access to a class like this. I wasn't too motivated either, as I just needed a couple of 500 level classes to graduate. The best thing I've made is a 3D mini-golf game with a couple of obsticles, an altitued change and multiple camera angles, and that was after a quarter long class. To be honest, the hardest thing about it was the ball physics. The graphics, cameras, and lighting was almost trivial, and I actually did the thing in about 24 hours of total work time or so (in the 2 days before it was due,of course).

Wintermute,
You don't need Calculus to understand the Build editor by Ken Silverman, which is what they used for Duke Nukem.
Calculus is great but you don't need it to understand 3D editors. 3D editors are pretty weird and it pays to read anything by others who have tackled them and won. I was very proud of my Duke Nukem level. Calculus.
frank

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Originally posted by Wintermute:
...Wanted to start this thread so I could pick the brains of you more experienced programers, especially 3D game developers. Ever since I saw Wolfenstein 3D, I've wanted to know how such software worked. Recently, I've purchased Borland C++ Builder 5 Standard and a few books on 3D graphics. My eyes have been opened; all that boredom I suffered sitting through Trigonometry class is starting to pay off...

At this point, I'm a serious C++ hobbyist trying to advance my skills enough to become a professional game developer (I know, we ALL want to write games).

Any advice (other than 'give up') would be most appreciated. At this point, I really need to know about good reference books, web sites, ect. that would be useful to someone at my level of proficiency. I am considering taking classes in Calculus to further my ability in Computer Science. As going to school is quite expensive, is this really necessary?

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I am not really too familar with Delphi but I think the main thing is C++, although it might take multiple passes to compile, creates a final product that is faster then Delphi...or so I hear. I use Borland C++ Builder 5.0 myself and it works fairly nicely, though it might compile slower then Delphi...

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Originally posted by BikeDude:

What about a large C++ program with a lot of header files, macros and stuff which forces the compiler to make multiple passes over the source code?

Compared with a language such as Object Pascal, most other languages pales in comparison. Borland Delphi is a single pass compiler which produces fairly good machine code (strong on string and integer stuff, not so good with fpu optimizations). Interestingly enough, it compiles very complex applications in seconds, whereas something comparable written in C++ would require minutes to compile unless you have the best iron Sun can throw at you (and the end result wouldn't necessarily be better).

In short: Delphi gives you the power of C++ while not being more difficult to master than VB.

There are two books about Delphi that is worth a read (on this subject), one covers OpenGL and the other specifically deals with game programming.

Another interesting point is that Delphi for Linux is in the works. I doubt we'll see MS VB or VC++ for Linux any time soon.

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Rune

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Originally posted by jtshaw:
I am not really too familar with Delphi but I think the main thing is C++, although it might take multiple passes to compile, creates a final product that is faster then Delphi...or so I hear.

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Actually, Delphi uses pretty much the same backend compiler as Borland C++ Builder... I think you'd be surprised if you did a couple of benchmarks.

If you compare with VC++ though, there are a couple of 'issues' you need to be aware of. Delphi programs by default sets the fpu to use extended for all internal calculations. VC++ defaults to Double. In addition, Delphi also enables fpu exceptions (I'm not sure about VC++). Level the playing field (there's a function called Set8087CW or something that'll let you get access to the fpu parameters) and suddenly whatever distance there was between Delphi and C++ isn't all that much.
http://www.optimalcode.com/ covers some aspects of optimizing Delphi and http://www.gamedeveloper.org/delphi3d/ seems to be a nifty game developer resource...

and finally: http://home.xnet.com/~johnjac/JCEC.htm runs some interesting challenges... (Delphi5 even seems to win a few of them)

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Rune

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Originally posted by Adisharr:
I have heard that learning C first may not be a good way to go.

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I was wondering about this myself. I'm in college right now. I took a semester of C++ a while back, and now I've transferred colleges to become a "Website Development" major, and am taking some programming classes in "C" now. I was wondering if I should be happy I'm doing C now, or somewhat disappointed I'm not working with C++ like I used to. So far I've found C and C++ to be fairly easy languages to understand. As long as you have a basic knowledge of the necessary components of programming, it's all abot learning the terms and the syntax. Pretty cut and dry, and pretty danm interesting too.

Oh, and in response to those wondering about which C is classified as, a "lowlevel" or "highlevel" language, my proffessors have always said both C/C++ are "mid-level" languages. Meaning, they're not quite assembly, but they're also a little more in touch with the hardware than Java or Pascal. An example would be, I don't think you can write a virus to flash someone's BIOS in Pascal can you? From what I've been told, only C/C++ have the power and functionality to get down and dirty with the system like that. (not that you would ever want to!)

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Originally posted by Grizzly:
Meaning, they're not quite assembly, but they're also a little more in touch with the hardware than Java or Pascal. An example would be, I don't think you can write a virus to flash someone's BIOS in Pascal can you?

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That has nothing to do with the language.

With Turbo Pascal you had every bit as much access to the hardware as you had with the other compilers at that time.

With 32 bit versions of Delphi, Borland chose to cut back on some of the old features. E.g. (IIRC) you can't access the old Port array (equivalent to in and out x86 instructions) plus its harder to access memory directly. You can however write assembly code whenever you feel like it:
function returnone: integer; assembler;
asm
mov eax, 1
ret
end;
should compile nicely in all versions of Delphi...

What current versions of Delphi _don't_ have is support for writing VxDs and NT device drivers. This requires rather intimate VC++ compatibility (linker format?) and was a feature only very recently added to Borland's C++ product (which btw is the easiest C++ development tool on the Windows platform to use, but once you discover why, you'll probably kick yourself for not learning Delphi in the first place).

It all boils down to what you want to do. Use VC++ to write device drivers because it's good at that, but if you don't use Delphi for virtually everything else, then you're burning valuable time (well, I don't know how much you value your time).

FWIW: There are those who use VC++ for the nitty gritty details of making device drivers, but as soon as they can use Delphi (Control Panel applets, .dll interfaces, NT service, _anything_) they immediately revert back to Delphi. The smallest console application written in Delphi clocks in at approx 10k.

C can be fun (I spent a year on a settop project that involved QNX and C programming which was fun for a while), but someone with one year worth of Delphi experience should be able to implement almost anything (except for device drivers :-) ) faster than someone with say 3 years worth of C/C++ experience. And the result should generally be better.

Since the OP compiler catches (way) more errors, you end up spending less time testing (which can be tedious at times -- thus someone came up with QA departments).

In short, Object Pascal is easier to read, maintain and compile.

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Rune

I have to say that whether somebody perfers C, C++, Java, Pascal, or whatever is a matter of personal prefference. The first language I ever learned was Pascal. I used it for a while and then I started learning C. Because I started using the unix environment C was a much better language for me to code in and I haven't touched pascal since. When I do programing in Windows I use Borland C++ Builder. I love the Borland interfaces and think that it has VC++ beat hands down (This is of course, just my opinion). I haven't used Delphi before but having read so many good posts about it I might dust the cobwebs out of that section of my brain that still knows pascal and give it a shot:P I guess the whole point of this post is to say that somebody else can't tell you what language you are going to like coding in better or what tools you will like using better. Some people "speak C" and love it, others think pointers are the devil and won't touch it. Eitherway, the only way you can know what you like the best is to try and give everything an honest shot.

John

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My computer said "WindowsME/2000 or better" so I installed Linux.

heh, this is a pretty darned interesting thread! Now could someone explain to me why some people would think that "pointers are the devil" in C? I personally find them kinda cool. C gives you the flexibility to pass by value, and pass by reference, why would that be a bad thing?

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Originally posted by Grizzly:
Now could someone explain to me why some people would think that "pointers are the devil" in C? I personally find them kinda cool.

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IMO although pointers are a pretty vital part of a language, there are sometimes ways of using them that borders on insanity.

I particulary remember struggling with function pointers in C. I fluidly understand the concepts involved and have no problems creating and using function callbacks in Pascal, yet in C I faced two problems: First of all, the declaration was ambigious and reading K&R didn't help much, second of all the compiler I used (Watcom C++) accepted virtually anything I threw at it, so I spent some time compiling and testing out the various way of declaring (and using!) these function pointers that I needed. And in this context, having compile times that well exceed (30-50 times slower) the familiar one second Pascal compile and link time is a grueling experience.

So the ironic thing is that with Object Pascal (and particulary Delphi) you'll be using function pointers all the time, and you might not even realise that it indeed is a function pointer.

Pascal:
type
TMyFunc = function(var i: integer; const s: string): boolean;

{ a function taking TMyFunc as arg }
function dostuff(f: TMyFunc; var i: integer): boolean;
begin
result := f(i, 'test');
end;

to use you'd simply say b := dostuff(myfunc, someint); No typecasting involved and no unpleasant surprises (it won't compile unless myfunc declaration _exactly_ matches the declaration of TMyFunc)...

You could _choose_ to typecast and thus override the type checking performed by the compiler, but in 99% of the cases there's no need to do so, and this leads to code that is much easier to maintain. E.g. if someone else working on your project changes the definition of TMyFunc, then he/she won't be able to compile until they've changed the rest of the code as well. The struggles I had with WC++ leads me to believe that this isn't so straightforward in C and thus effectively hinders cross-project collaboration to a great extent.

But I guess this could be an issue that only haunts me.

Other pitfalls that I fell into (or rather annoyed by): Logical vs bitwise operators. There's a difference between & and &&, | and | |, and so on. In Pascal the compiler knows when an and is a bitwise or a logical operator and 'and' is spelt out. In C, this makes perfect sense: x=x+3. Show that to your math teacher, and he'll slap you silly. Once, I even managed to miss an equal sign and typed "if i=0" (or something) and it took a while before it dawned on me that I had actually missed a keystroke (I type touch and have problems reaching the upper row sometimes, besides, on Norwegian keyboards '=' requires that you hit SHIFT-0 making it a doubly awkard character to type). I've been told since that some programmers type if 0==i because this would produce a compiler error if they missed a keystroke... (IMHO that workaround makes the code even more unreadable)

In any case, no time during my one year stint as a professional C programmer did I catch myself thinking "boy, this would've been a lot harder in Pascal" or "wow, this outperforms Pascal a lot". Au contraire. Performance doesn't equate to cryptic code written in a language that was created in the 70s so that larger programs could fit in 3K of memory. Performance is about good algorithms and good coding practices (but some languages make it easier to adapt good habits -- hungarian notation isn't very common in the Pascal world, simply because it's rarely needed!).

I guess it (for me) boils down to that I consider programming an art. C/C++ is much too coarse a canvas for me to paint on, so I choose a somewhat finer and more refined canvas that can bring out the finer details I want to express in less time (while still being able to use the ol' paint roller on the wide areas that doesn't require as much detail and thought). I loathe modern art, but I guess as long as people use their creativity for good, everything is all right in the end.

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Rune