Calculate HRTF stepping params right before mixing

This means we track the current params and the target params, rather than the
target params and the stepping. This closer matches the non-HRTF mixers.

1 files changed, 36 insertions, 4 deletions

diff --git a/Alc/mixer.c b/Alc/mixer.c
index 4688c89e..6b5272ea 100644
--- a/Alc/mixer.c
+++ b/Alc/mixer.c
@@ -601,9 +601,42 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam
                         currents[j] = gains[j].Current;
                 }
                 else
-                    MixHrtfSamples(parms->OutBuffer, samples, parms->HrtfCounter, voice->Offset,
-                                   OutPos, IrSize, &parms->Hrtf[chan].Params,
-                                   &parms->Hrtf[chan].State, DstBufferSize);
+                {
+                    MixHrtfParams hrtfparams;
+                    if(!Counter)
+                    {
+                        parms->Hrtf[chan].Current = parms->Hrtf[chan].Target;
+                        for(j = 0;j < HRIR_LENGTH;j++)
+                        {
+                            hrtfparams.Steps.Coeffs[j][0] = 0.0f;
+                            hrtfparams.Steps.Coeffs[j][1] = 0.0f;
+                        }
+                        hrtfparams.Steps.Delay[0] = 0;
+                        hrtfparams.Steps.Delay[1] = 0;
+                    }
+                    else
+                    {
+                        ALfloat coeffdiff;
+                        ALint delaydiff;
+                        for(j = 0;j < HRIR_LENGTH;j++)
+                        {
+                            coeffdiff = parms->Hrtf[chan].Target.Coeffs[j][0] - parms->Hrtf[chan].Current.Coeffs[j][0];
+                            hrtfparams.Steps.Coeffs[j][0] = coeffdiff * Delta;
+                            coeffdiff = parms->Hrtf[chan].Target.Coeffs[j][1] - parms->Hrtf[chan].Current.Coeffs[j][1];
+                            hrtfparams.Steps.Coeffs[j][1] = coeffdiff * Delta;
+                        }
+                        delaydiff = (ALint)(parms->Hrtf[chan].Target.Delay[0] - parms->Hrtf[chan].Current.Delay[0]);
+                        hrtfparams.Steps.Delay[0] = fastf2i((ALfloat)delaydiff * Delta);
+                        delaydiff = (ALint)(parms->Hrtf[chan].Target.Delay[1] - parms->Hrtf[chan].Current.Delay[1]);
+                        hrtfparams.Steps.Delay[1] = fastf2i((ALfloat)delaydiff * Delta);
+                    }
+                    hrtfparams.Target = &parms->Hrtf[chan].Target;
+                    hrtfparams.Current = &parms->Hrtf[chan].Current;
+
+                    MixHrtfSamples(parms->OutBuffer, samples, Counter, voice->Offset,
+                                   OutPos, IrSize, &hrtfparams, &parms->Hrtf[chan].State,
+                                   DstBufferSize);
+                }
             }
 
             for(j = 0;j < Device->NumAuxSends;j++)
@@ -664,7 +697,6 @@ ALvoid MixSource(ALvoice *voice, ALsource *Source, ALCdevice *Device, ALuint Sam
 
         OutPos += DstBufferSize;
         voice->Offset += DstBufferSize;
-        voice->Direct.HrtfCounter = maxu(voice->Direct.HrtfCounter, DstBufferSize) - DstBufferSize;
 
         /* Handle looping sources */
         while(1)