Improve sound/audio propagation and acoustics

[hemebond]

Sound in Quake, by default, seems to use the VIS data to determine what (ambient) sounds are audible to a player. For example, in this image, the slime ambient sound is audible from 1, and 2, but not 3.

It would be great if it were possible to have sounds propagate through the level based on the actual geometry, including dynamic elements like doors.

[Cloudwalk9]

This would entail an implementation of a PHS (potentially hearable set) if I'm not mistaken.

[uis246]

I think Valve call it Potentially Audible Set. I'm not sure how they do this, but I think it should be done as minimal amplitude of sound, that can be heared.

[bones-was-here]

OpenAL Soft (LGPL) has a plugin for this, Steam Audio (Apache-2.0) does too. Not sure which is easier to work with, but OpenAL is packaged in distros.

[uis246]

I tried to work with OpenAL in AltCraft. Got positional sound very quickly. Never done anything with Steam Audio.