Step mixing gains per-sample for non-HRTF mixing

This fades the dry mixing gains using a logarithmic curve, which should produce
a smoother transition than a linear one. It functions similarly to a linear
fade except that

step = (target - current) / numsteps;
...
gain += step;

becomes

step = powf(target / current, 1.0f / numsteps);
...
gain *= step;

where 'target' and 'current' are clamped to a lower bound that is greater than
0 (which makes no sense on a logarithmic scale).

Consequently, the non-HRTF direct mixers do not do not feed into the click
removal and pending click buffers, as this per-sample fading would do an
adequate job of stopping clicks and pops caused by extreme gain changes. These
buffers should be removed shortly.

1 files changed, 1 insertions, 1 deletions

diff --git a/Alc/mixer.c b/Alc/mixer.c
index 8ce7d845..96acb3e8 100644
--- a/Alc/mixer.c
+++ b/Alc/mixer.c
@@ -411,7 +411,7 @@ ALvoid MixSource(ALactivesource *src, ALCdevice *Device, ALuint SamplesToDo)
     Source->BuffersPlayed     = BuffersPlayed;
     Source->position          = DataPosInt;
     Source->position_fraction = DataPosFrac;
-    src->Direct.Mix.Hrtf.State.Offset += OutPos;
+    src->Direct.Offset += OutPos;
     if(State == AL_PLAYING)
         src->Direct.Counter = maxu(src->Direct.Counter, OutPos) - OutPos;
     else