[Solved] Sounds on the same channel always get cut off

[Cherno]

It seems like you can't prevent playing a sound on a channel to cut off a sound that is already playing on the same channel.

Example case:
Your minigun has a looping fire state where you want to play a looping firing sound, but only if the sound is not already being played on the channel.

using A_StartSound with CHANF_LOOPING (which means CHANF_LOOP and CHANF_NOSTOP), or just CHANF_NOSTOP, makes no difference; the sound already playing on the channel will always be cut off.

I constructed a simple showcase. Just load it with Doom.wad or Doom2.wad, summon the "Test" actor, and hear the shotgun sound being cut off by the pistol sound.

gzlooptest.pk3

[Player701]

It seems that CHANF_NOSTOP only works if an actor is already playing the same sound that A_StartSound wants to play. Not sure if this is a bug or by design. The wiki seems to suggest the former, though. But do note that it's been like that at since at least 4.3.1.

Addendum: The article for A_PlaySound claims (emphasis mine):

CHAN_NOSTOP (4096) — Do not override the sound that is currently playing on the same channel with this one. This is only the case if both sounds are the same. If they are different, the playing sound is overridden regardless.

However, A_StartSound instead says:

CHANF_NOSTOP — if the channel is occupied, do not play the sound

Since the A_PlaySound article was written first, I assume that this is isn't a bug but intended behavior.

[Graf Zahl]

"Written first" is meaningless. "Changed most recently" is more important. It may be that somebody edited the A_PlaySound page but forgot A_StartSound.

[Player701]

CHANF_NOSTOP was added to the A_PlaySound article about 2.5 years ago by Blue Shadow. A_StartSound didn't exist at that time.

And it was none other than you, Graf, who added that flag, among a few others, to the A_StartSound article in January this year. Note that the description was already incorrect back then, and no one has edited it since.

[Cherno]

Thanks for the clarification. I only use A_Startsound nowadays so I didn't know about that crucial bit of info

Anyway, to get the behavior I wanted, I simply used IsActorPlayingSound to check if the sound is already playing.