problem with volume and .sndshd files

[BenzoSt]

Describe the bug
.sndshd files can't effectively amplify the volume of sounds.

Your System

• What operating system are you using, what CPU and GPU, which GPU driver version?
  Windows 11 Pro 24H2, Ryzen 7700, Radeon RX 9070, 25.8.1

• What version of dhewm3 are you using? (Also: Official download? Package from Linux distro? MacSourcePorts? Did you compile yourself?)
  Dhewm3 1.5.4

To Reproduce
Describe how to reproduce the bug

1. (playing in windowed mode) Fire my pistol and listen to the sound.
2. Alt+Tab, open the file weapons.sndshd
3. Adjust the volume for player_pistol_fire
4. Save weapons.sndshd
5. In Dhewm3, open console, type "reloaddecls", {ENTER}
6. Fire my pistol again and listen.
7. I notice that lowering the volume of player_pistol_fire causes my shots to be quieter, but increasing the volume has no effect no matter how high I set the value.

This seems to affect all sounds in weapons.sndshd when I try to increase the volume. Once again, I am indeed able to lower the volume... but not increase it.

[DanielGibson]

I can't reproduce this.
If I set the volume to a negative value reloadDecls works and makes the pistol quieter.
If I then set it back to 13 and run reloadDecls again, it's loud again.

If you're wondering why values > 13 don't work: The values from the sndsh are in dezibel, and before being set in OpenAL are converted to.. IDK.. some linear unit?.. (basically) with
volume = pow(2, sndshader->parms.volume / 6); ($2^{\frac{shdvol}{6}}$)
So for 13 the value is about 2.52.
That volume is then scaled a bit according to your global Doom3 volume and also according to the sound sources distance and the configured min/max distance - for the pistol sound that probably doesn't do much as it's very close to the player.
Then it's clamped to 1.0 and set as AL_GAIN. Clamping is necessary, because AL_GAIN only supports values <= 1.0

(If s_scaleDownAndClamp is enabled, it also clamps the value to 1 and and then scales it to 1/3 before clamping it to 1 and sending it to OpenAL but that doesn't make a difference here).

So especially for player weapon effects those relatively big volume numbers don't make much sense because they're clamped to 1.0 (volume 0 in shader) anyway...
(Maybe they make sense when reused for monsters that are further away from the player, and they indeed are, because then their pistol has the maximum volume no matter if they're right in front of the player or some distance away and only gets quieter when they're even further away)

See also #179, #326 or bibendovsky/eaxefx#28 (comment)