id Software C++ Coding Conventions

7 thoughts on “id Software C++ Coding Conventions”

1. Hightree 2008/11/11 at 11:49

   Thanks a bundle !
   This will make a great template for our own coding conventions doc.
2. JeGX Post Author2008/11/11 at 11:59

   Cool 😉 I’m glad this find is useful.
3. saew 2008/11/11 at 20:53

   I think ID has very few experience with C++. They used C a loooong time and they started to program their games using C++ just a few years ( for Quake Wars I think ).

   I’m programming C++ for 10 years and that doc clearly shows some immature decisions, for example:

   if ( x ) {
   blah valh
   }else {
   }

   that’s ugly notation that does not help at all the code readability and neither correct code identation. It’s way better this other one:

   if ( x )
   {
   //blah blah
   }
   else
   {
   //blah blah
   }

   ( which is called ANSI C++ style brackets btw ).

   Other thing I don’t like is that pseudo-hungary notation with the _t at the end

   struct myStruct_t

   almost all the code editors in the world ( VS, NetBeans, Eclipse, SlickEdit, etc etc ) can tell you if a data structure is a struct, a class, an integer, etc in the debug watch, class navigators, etc… actually, I think there is no need at all to use hungary notation and neither that 80-era _t thing.

   They’s are using “float” also which is terribly bad. A good practise is to re-map floating point types to custom typedefs or classes, so you can alter the type them easy. For example, imagine you’re developing a mobile game and that platform does not suppport floats… with custom classes or a typedef you can use fixed fp precision or whatever…
4. JeGX Post Author2008/11/12 at 09:41

   Totally OK with you. Thanks for your contribution saew, interesting reading 😉

   The convention

   if ( x ) {
   blah valh
   }else {
   }

   is awful and I prefer a more compact manner like this:
   if (x)
   {
   doSomething1();
   doSomething2();
   }
   else
   {
   doSomething3();
   doSomething4();
   }

   or

   if (x)
   doSomething1();
   else
   doSomething2();

   But I appreciate the fact id Software has a coding convention paper and this is a good example to follow with of course, each one with his own conventions!
5. Philip Spencer 2008/12/02 at 12:31

   Nice to see someone’s best practice recommendations. I’ve been coding in flavours of C for over 20 years, and would support ID’s layout choice regarding braces:
   if ( x ) {
   blah valh;
   } else {
   vlah balh;
   }

   for two primary reasons:

   1: Safety in code maintenance. Many times I have seen the alternate format accidentally split, changing the code flow but not generating compile warnings:
   if ( x )
   {
   blah blah;
   }
   else
   line added during maintenance;
   {
   blah blah;
   }

   or the simple case
   if ( x )
   line added during maintenance;
   {
   blah blah;
   }

   The most common instance is the accidental
   for ( ix = 0; ix < END_IX; ix++ );
   {
   copy[ix] = original[ix];
   }

   Legal code and hard to spot, but not what is intended.

   2: Compact presentation. Either on an old-fashioned glass teletype screen, or in a typical small window in a GUI environment, one is often performing keyhole surgery on the source code, and this format maximises the quantity of functional code visible.

   I also like the way that the closing brace matches the start conditional (or function, or loop control, etc), and the clearer indentation (IMHO).
6. Jason McGuiness 2008/12/02 at 18:18

   Might I suggest a more modern, and comprehensive work upon which one may base their coding standards? (That is also peer-reviewed.) My suggestion is:

   “C++ Coding Standards” by H. Sutter et al, Addison-Wesley, Feb 2005.
7. Andreas 2013/10/11 at 02:33

   Guys, it’s not about the particular choice of conventions id uses. The point is to have such a paper, and make it available to every developer.

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