Ignore music playing state when game is paused

[ilmoro93]

As reported in #2180, the music doesn't restart when the game is resumed from pause.

This PR fixes it by preventing Play music option to be unselected by cfg.musicPlaying = playMusic(mi.pathId, cfg.volume, false); in playBackgroundMusic() when game isPaused().

But there is still a problem: when resuming in Locomotion the music is actually resumed, while in OpenLoco it restarts from the beginning.

Moreover I have noticed that clicking Load Saved Game in main menu also stops the music.

I don't know if we should solve everything in one PR or you can review and merge this little fix only.

[AaronVanGeffen]

But there is still a problem: when resuming in Locomotion the music is actually resumed, while in OpenLoco it restarts from the beginning.

Unlike vanilla, OpenLoco does not keep track of music progression. That much is currently delegated to the stream library (OpenAL). We could potentially reintroduce this, though, by querying track progression before the stream is cut.

[ZehMatt]

But there is still a problem: when resuming in Locomotion the music is actually resumed, while in OpenLoco it restarts from the beginning.

Unlike vanilla, OpenLoco does not keep track of music progression. That much is currently delegated to the stream library (OpenAL). We could potentially reintroduce this, though, by querying track progression before the stream is cut.

Do we need to track the progress? I think pause/resume functionality exists in OpenAL so we don't have to do that ourselves.

[ilmoro93]

I have tried the alSourcePause() function of OpenAL. If I get a working solution I will make a PR in the next days to fix #2180 and to enable music resume after pause.

[ilmoro93]

I think Audio::playMusic() should not return bool. The return value is only used in playBackgroundMusic() and assigned to cfg.musicPlaying, which unselects the Play music option, and I think this is wrong (see #2180 (comment)).
What do you think?

[LeftofZen]

perhaps a broader discussion; should the music pause at all when the user pauses the game? the ambient track does not pause, so perhaps either it should, or the music shouldn't

[LeftofZen]

• functionality works but also introduces a bug - if you mute the audio with
  
  then the playlist cycles through tracks infinitely. this does not happen in 24.04
• needs changelog

[ilmoro93]

perhaps a broader discussion; should the music pause at all when the user pauses the game? the ambient track does not pause, so perhaps either it should, or the music shouldn't

I think every sound should pause when the game is paused, like vanilla. I find it more intuitive, it makes it clear that game is playing when music resumes.