[Guide] Compile GZDoom on OpenBSD

[Cacodemon345]

This is a guide on how to compile GZDoom on OpenBSD.

Prerequisites (package/port name in parentheses):

1. OpenAL Soft (openal)
2. SDL2 (sdl2)
3. Fluidsynth (fluidsynth, optional)
4. CMake (cmake)
5. libsndfile (libsndfile)
6. libogg (libogg)
7. GCC from ports/package repository (gcc, g++, available separately)
8. Git (git)

Instructions:

• Install the prerequisites like this as root:

  Code: Select all

  pkg_add name-of-package

  Where name-of-package is the name of prerequisite to install. You can optionally install the first 6 prerequisites from the upstreams but the last two must be installed from OpenBSD package repository.
• Clone the GZDoom and ZMusic upstream git repository:

  Code: Select all

  git clone --recursive https://github.com/coelckers/gzdoom
  git clone https://github.com/coelckers/ZMusic

• Compile ZMusic:

  Code: Select all

  cd ZMusic
  mkdir build
  cmake -S ./ -B ./build/ -DCMAKE_C_COMPILER=egcc -DCMAKE_CXX_COMPILER=eg++
  cd build
  make
  make install # run this as root

• Compile GZDoom:

  Code: Select all

  cd gzdoom
  mkdir build
  cmake -S ./ -B ./build/ -DCMAKE_C_COMPILER=egcc -DCMAKE_CXX_COMPILER=eg++ -DCMAKE_PREFIX_PATH=/path/to/ZMusic/build/source/
  cd build
  make

Make sure to suffix the "-jn" argument to the make commands, where "n" is the number of cores you have. Otherwise the builds will be slow.

If you successfully built GZDoom, you should see an executable named "gzdoom" inside the build directory. Copy your IWADs to this directory.

Now launch GZDoom, you should see it making to the title screen.

Problems:

• I get a black screen after GZDoom launches.
  Cause: Likely related to some dumb changes the OpenBSD developers made to the GLX component (I believe) in Xenocara Mesa3D that causes OpenGL context creation to fail internally despite being reported as being successful to the SDL2 application.
  Solution: Launch GZDoom with EGL forced like this:

  Code: Select all

  SDL_VIDEO_X11_FORCE_EGL=1 ./gzdoom

  This will force SDL2 to use EGL instead of GLX for OpenGL.
• Size mismatch messages followed by a segmentation fault
  Cause: This will happen if you type "make install" as root after building GZDoom without launching it first from the build directory, causing the OpenBSD executable loader to think that the RTTI classes/structs have different sizes across C++ libraries, leading to a segmentation fault.
  Solution: Launch it first from the build directory before running "make install" as root.
• GZDoom's crash reporter does not work properly.
  Cause: GZDoom launches the "gdb" program when a crash happens, which in OpenBSD is very old and non-working as compared to GDB from ports which is named "egdb".
  Solution: I will do a solution later, once I figure it out.
• Vulkan isn't working.
  Cause: ICD files are not available.
  Solution: Create an ICD file by yourself and save them in ~/.local/share/vulkan/icd.d/. See https://github.com/KhronosGroup/Vulkan- ... ile-format for the format.

Let me know if there are problems while following this guide.

[Cacodemon345]

Update:
I updated the problems list. Also, the upstream SDL2 now features functional KMSDRM support for OpenBSD complete with WSCONS input backend. You have to edit the /etc/fbtab file for it to work.