DOOM VS GLFW

commercially exploit or use for any commercial purpose."

[1] https://github.com/id-Software/DOOM/commit/4eb368a960647c8cc...

The original Doom had third-party audio playback routines, so the source came with a rewritten sound server: https://github.com/id-Software/DOOM/tree/master/sndserv

    The bad news:  this code only compiles and runs on linux.  We couldn't

Here's a repo for you with no test coverage and no auto-generated DI. They using unsafe pointers all over the place, too!

https://github.com/id-Software/DOOM

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!

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. https://github.com/curl/curl/blob/master/lib/dynhds.h (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 https://github.com/id-Software/DOOM.

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 https://clang.llvm.org/docs/AddressSanitizer.html 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 ;)

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.

[1] https://github.com/id-Software/DOOM

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.

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

https://en.wikipedia.org/wiki/Region-based_memory_management

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:

https://github.com/mit-pdos/xv6-public (based on code from the 70's)

https://github.com/id-Software/DOOM (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.

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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:

https://www.oilshell.org/blog/2023/01/garbage-collector.html

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.

Doom

Minecraft runs on various Javas.

And there's a known issue with an interaction between minecraft, Java, and the video drivers that crashes out and it can be traced back all the way to here: https://github.com/glfw/glfw/issues/1997

It's not fixed.

Window context manager - glfw, sdl

Types of tools for creating a gui (and how those tools approximately work): 1. Utilize the native _graphical interface API_, and depending on the platform, they have specific layers to interface: * Wayland, X11, for Linux * [GDI](https://learn.microsoft.com/en-us/windows/win32/gdi/windows-gdi) for windows * [Quartz](https://en.wikipedia.org/wiki/Quartz\_(graphics\_layer)) for macOS Example - GTK uses [wayland](https://gitlab.gnome.org/GNOME/gtk/-/blob/main/docs/reference/gdk/wayland.md) ([source code](https://gitlab.gnome.org/GNOME/gtk/-/tree/main/gdk/win32)) [X11](https://gitlab.gnome.org/GNOME/gtk/-/blob/main/docs/reference/gdk/x11.md) ([source code](https://gitlab.gnome.org/GNOME/gtk/-/tree/main/gdk/x11)) GDI ([source code](https://gitlab.gnome.org/GNOME/gtk/-/tree/main/gdk/win32)) Quartz ([source code](https://gitlab.gnome.org/GNOME/gtk/-/tree/main/gdk/macos)) [How to use wayland display server](https://bugaevc.gitbooks.io/writing-wayland-clients/content/black-square/the-wayland-client-library.html) (TODO missing "animation" section) 2. Utilize opengl _or other low level graphics api's_ with window context, use GPU to render widgets * Window context manager - [glfw](https://github.com/glfw/glfw), [sdl](https://www.libsdl.org/) * contexts and surfaces, reading input, handling events Example: ImGui, NanoVG, Nuklear, raylib Why? Mainly used for game development, but also good for gui's. _(i haven't seen any examples that uses this method that are used for developing general-use graphical user interfaces.)_

GLFW: A library for window creation and managing user input.

Not SDL2, but GLFW has something like that under the tests/ directory:

https://github.com/glfw/glfw/blob/master/tests/triangle-vulk...

I'm not familiar with LWJGL, my 5 seconds on their website makes me think you might be looking for something like GLFW https://www.glfw.org/ to handle I/O and window creation/management.

Consider GLFW3 for windowing and GLAD for function loading. I've used this combination myself successfully. Granted, that is "two things" you need, but OTOH it'll work well.

There is a pattern to it which is usable with every GitHub repository. For example, GLFW v3.3.8 can be fetched from: https://github.com/glfw/glfw/archive/refs/tags/3.3.8.tar.gz

That is a static or import library for glfw. You need add the path to the directory where this file is located to the "library directories", see: https://www.learncpp.com/cpp-tutorial/a2-using-libraries-with-visual-studio-2005-express/