Fix to play SDL_audio on current device by default

[dartfnm]

• There was no sound in quaesar because it uses the sound SDL_Audio device at index 0, not the current audio device in the OS. So now it will choose the current OS audio device unless the user has explicitly specified a different device in the config.

[emoon]

Thanks for the PR.

It seems that the function is missing in some version (?) of SDL2

/usr/bin/clang++-9 -DFSUAE -I/home/runner/work/quaesar/quaesar/uae_src/include -I/home/runner/work/quaesar/quaesar/uae_src -I/home/runner/work/quaesar/quaesar/src -I/home/runner/work/quaesar/quaesar/. -I/usr/include/SDL2 -I/home/runner/work/quaesar/quaesar/external/ADFlib/src -I/home/runner/work/quaesar/quaesar/temp/external/zlib -I/home/runner/work/quaesar/quaesar/external/zlib -std=gnu++17 -DUAE=1 -D_cdecl= -DFILEFLAG_WRITE=1 -DOS_NAME=\"linux\" -DUSHORT=uint16_t -DHWND=uint32_t -DHRESULT=uint32_t -DWPARAM=uint16_t -DLPARAM=uint32_t -DFILEFLAG_DIR=1 -D_ftelli64=ftello64 -D_fseeki64=fseeko64 -MD -MT CMakeFiles/quaesar.dir/src/sounddep/sound.cpp.o -MF CMakeFiles/quaesar.dir/src/sounddep/sound.cpp.o.d -o CMakeFiles/quaesar.dir/src/sounddep/sound.cpp.o -c /home/runner/work/quaesar/quaesar/src/sounddep/sound.cpp
/home/runner/work/quaesar/quaesar/src/sounddep/sound.cpp:370:9: error: use of undeclared identifier 'SDL_GetDefaultAudioInfo'
    if (SDL_GetDefaultAudioInfo(&cur_driver, &spec, 0) == 0) {

Any idea here?

[dartfnm]

Yes, it is strange according to the documentation this function was added in 2022 in SDL version 2.24.0.
It looks like the problem is in CMake, since the quaesar\external\sdl2\include\SDL_audio.h folder contains the new version of SDL.
It seems that for UNIX you need to update the SDL version or give it the correct path, like here:

quaesar/CMakeLists.txt

Line 222 in d4ddb42

target_include_directories(quaesar PRIVATE "${CMAKE_SOURCE_DIR}/external/sdl2/include")

But I don't know how to do it correctly on Linux.

[emoon]

The way it works is that the system version of SDL is used on Linux and for Windows an included version is used. As listed above

-I/usr/include/SDL2 for the commandline

It seems to only happen on Ubuntu 20.04 which is an older version. I try to allow coming the code for older systems. My guess is that the older of Ubuntu has an older version of SDL2 installed, but maybe it's possible to to update the installed SDL2 version. Otherwise it might be possible with an #ifdef that checks the SDL version if the function is included or not.

It seems that libsdl2-2.0-0 gets installed.

[emoon]

What I think the best approach here is to use

#if SDL_VERSION_ATLEAST(2, 24, 0)
  ... code that uses SDL_GetDefaultAudioInfo(...)
#endif

So older SDL2 versions will still work, but just not get the default audio device selected.

[dartfnm]

What I think the best approach here is to use

#if SDL_VERSION_ATLEAST(2, 24, 0)
  ... code that uses SDL_GetDefaultAudioInfo(...)
#endif

All right, done.

[dartfnm]

Fixed it in 2nd commit, but I don't know how to run the CI check again. It didn't start automatically.

[emoon]

Yeah, the maintainer has to trigger the CI manually for new user PRs (it's because in the past bots open up tons of PR on many repos and because CI started the injected crypto mining and what not)

[emoon]

Seems to pass now. Thanks for the fix!