DOOM Open Source Release (by id-Software)

DOOM Alternatives

Similar projects and alternatives to DOOM

NOTE: The number of mentions on this list indicates mentions on common posts plus user suggested alternatives. Hence, a higher number means a better DOOM alternative or higher similarity.

DOOM reviews and mentions

Posts with mentions or reviews of DOOM. We have used some of these posts to build our list of alternatives and similar projects. The last one was on 2024-01-17.
  • Doom Released Under GPLv2
    4 projects | | 17 Jan 2024
    commercially exploit or use for any commercial purpose."


    4 projects | | 17 Jan 2024
    This Github repo was previously released with this license:

    4 projects | | 17 Jan 2024
  • GTA 5 source code leaks online
    3 projects | | 25 Dec 2023
    The original Doom had third-party audio playback routines, so the source came with a rewritten sound server:

        The bad news:  this code only compiles and runs on linux.  We couldn't
  • Software Disenchantment
    5 projects | | 23 Oct 2023
    Here's a repo for you with no test coverage and no auto-generated DI. They using unsafe pointers all over the place, too!

    Shall I prepare the postage for the letter in which you'll call John Carmack an MBA? Should we send another to Chris Sawyer? I heard he didn't even write a formal design doc for Roller Coaster Tycoon!

  • Ask HN: Good practices for my first C project
    3 projects | | 18 Oct 2023
    cURL is one of the most used C libs and is an example of good quality C code. If you follow the style used there, see e.g. (and associated dynhds.c) you will be good.

    Looking at the source of some of the old game-engines from the era that have since been released as open-source can also be helpful, like

    In both cases notice how simple and elegant a lot of the code is. There is already enough complexity inherent in the problem they are solving, and that is where the focus should be.

    Any IDE with a working language server to make it easy to jump around and refactor should work fine. Limitations might be due to the C language itself?

    Error handling on such a fixed platform does not need to be super-advanced. You should always be within the confines of the system so there shouldn't be much that can go wrong. If stuff goes wrong anyway just being able call a function Fatal("FooBar failed with code 34") when unexpected stuff happens and have it log somewhere to be able to dig around should be enough. You never need to be able to recover and retry.

    Make sure to use or a similar tool when developing outside of the PSOne.

    That said, consider statically allocating global buffers for most stuff and avoid using the heap for most stuff.

    Good luck working within the confines of the PSOne! Many hackers have pulled the hair from their head on that platform ;)

  • Ask HN: Where do I find good code to read?
    22 projects | | 24 Aug 2023
  • Running Stable Diffusion in 260MB of RAM
    3 projects | | 20 Jul 2023
    Probably more easily than you'd think. DOOM is open source[1], and as GP alludes, is probably the most frequently ported game in existence, so its source code almost certainly appears multiple times in GPT-4's training set, likely alongside multiple annotated explanations.


  • Some were meant for C [pdf]
    2 projects | | 21 Jun 2023
    I'd define an arena as the pattern where the arena itself owns N objects. So you free the arena to free all objects.

    My first job was at EA working on console games (PS2, GameCube, XBox, no OS or virtual memory on any of them), and while at the time I was too junior to touch the memory allocators themselves, we were definitely not malloc-ing and freeing all the time.

    It was more like you load data for the level in one stage, which creates a ton of data structures, and then you enter a loop to draw every frame quickly. There were many global variables.


    Wikipedia calls it a region, zone, arena, area, or memory context, and that seems about right:

    It describes history from 1967 (before C was invented!) and has some good examples from Apache ("pools") and Postgres ("memory contexts").

    I also just looked at these codebases: (based on code from the 70's) (1997)

    I looked at allocproc() in xv6, and gives you an object from a fixed global array. A lot of C code in the 80's and 90's was essentially "kernel code" in that it didn't have an OS underneath it. Embedded systems didn't run on full-fledges OSes.

    DOOM tends to use a lot of what I would call "pools" -- arrays of objects of a fixed size, and that's basically what I remember from EA.

    Though in g_game.c, there is definitely an arena of size 0x20000 called "demobuffer". It's used with a bump allocator.


    So I'd say

    - malloc / free of individual objects was NEVER what C code looked like (aside from toy code in college)

    - arena allocators were used, but global vars and pools are also very common.

    - arenas are more or less wash for memory safety. they help you in some ways, but hurt you in others.

    The reason C programmers don't malloc/free all the time is for speed, not memory safety. Arenas are still unsafe.

    When you free an arena, you have no guarantee there's nothing that points to it anymore.

    Also, something that shouldn't be underestimated is that arena allocators break tools like ASAN, which use the malloc() free() interface. This was underscored to me by writing a garbage collector -- the custom allocator "broke" ASAN, and that was actually a problem:

    If you want memory safety in your C code, you should be using ASAN (dynamically instrumented allocators) and good test coverage. Arenas don't help -- they can actually hurt. An arena is a trivial idea -- the problem is more if that usage pattern actually matches your application, and apps evolve over time.

  • Is it possible to see the code of 90s computer games?
    10 projects | /r/learnprogramming | 2 Jun 2023
    Doom might be the best one, they released their code i don't remember when. It's in github if you want to check it out: link
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