[Bug]Sound - stereo separation 0% = 100%

[NoX1911]

The Sound/'stereo separation' 0% setting is wrong. Instead of 0% (mono) its 100% (fully separated).
(Same system environment and bootlog as [Bug]WinUAE filter settings slider behavior).

[8bitbubsy]

This is (I think!) because the code is not setting 0% manually to STEREO_CENTER_POS...
The reason they are not processing 0 is because of "division by zero". Seems like they just forgot to do

if (val <= 0){
    pan1 = PAN_CENTER;
    pan2 = PAN_CENTER;
    pan3 = PAN_CENTER;
    pan4 = PAN_CENTER;
}else{
    // scale calculation here
}

I guess it instead defaults to the normal Paula pan (0,255,255,0) settings, in case of 0.

[Toni Wilen]

Originally Posted by NoX1911

The Sound/'stereo separation' 0% setting is wrong.

Confirmed.

Originally Posted by 8bitbubsy

This is (I think!) because the code is not setting 0% manually to STEREO_CENTER_POS...
The reason they are not processing 0 is because of "division by zero". Seems like they just forgot to do

The most wrong guess ever.

Off by one in test that checks if stereo processing (separation+delay) can be skipped completely for performance reasons.

[8bitbubsy]

Originally Posted by Toni Wilen

The most wrong guess ever.

Off by one in test that checks if stereo processing (separation+delay) can be skipped completely for performance reasons.

This is me:

I guess you're right, I somehow thought the code did some_var/stereo_sep instead of stereo_sep*3/2. (some_var/stereo_sep would cause a division by zero if stereo_sep was 0)

audio.c:

/* If sound_stereo_separation is 0:
** sep = ((0 * 3) / 2) = 0
*/

sep = (currprefs.sound_stereo_separation = changed_prefs.sound_stereo_separation) * 3 / 2;
mixed_mul1 = MIXED_STEREO_SCALE / 2 - sep;
mixed_mul2 = MIXED_STEREO_SCALE / 2 + sep;

// sep > 0! 
mixed_on = (sep > 0 && sep < MIXED_STEREO_MAX) || mixed_stereo_size > 0;