Separate two HRTF passes into two loops

1 files changed, 21 insertions, 16 deletions

diff --git a/Alc/mixer/hrtfbase.h b/Alc/mixer/hrtfbase.h
index 8549f6ba..571cdc89 100644
--- a/Alc/mixer/hrtfbase.h
+++ b/Alc/mixer/hrtfbase.h
@@ -23,13 +23,12 @@ inline void MixHrtfBase(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
     const auto &Coeffs = *hrtfparams->Coeffs;
     const ALfloat gainstep{hrtfparams->GainStep};
     const ALfloat gain{hrtfparams->Gain};
-    ALfloat stepcount{0.0f};
 
     ALsizei Delay[2]{
         HRTF_HISTORY_LENGTH - hrtfparams->Delay[0],
         HRTF_HISTORY_LENGTH - hrtfparams->Delay[1] };
     ASSUME(Delay[0] >= 0 && Delay[1] >= 0);
-
+    ALfloat stepcount{0.0f};
     for(ALsizei i{0};i < BufferSize;++i)
     {
         const ALfloat g{gain + gainstep*stepcount};
@@ -39,6 +38,7 @@ inline void MixHrtfBase(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
 
         stepcount += 1.0f;
     }
+
     for(ALsizei i{0};i < BufferSize;++i)
         LeftOut[OutPos+i]  += AccumSamples[i][0];
     for(ALsizei i{0};i < BufferSize;++i)
@@ -58,35 +58,40 @@ inline void MixHrtfBlendBase(FloatBufferLine &LeftOut, FloatBufferLine &RightOut
     const ALfloat oldGainStep{-oldGain / static_cast<ALfloat>(BufferSize)};
     const auto &NewCoeffs = *newparams->Coeffs;
     const ALfloat newGainStep{newparams->GainStep};
-    ALfloat stepcount{0.0f};
 
     ASSUME(OutPos >= 0);
     ASSUME(IrSize >= 4);
     ASSUME(BufferSize > 0);
 
-    ALsizei OldDelay[2]{
+    ALsizei Delay[2]{
         HRTF_HISTORY_LENGTH - oldparams->Delay[0],
         HRTF_HISTORY_LENGTH - oldparams->Delay[1] };
-    ASSUME(OldDelay[0] >= 0 && OldDelay[1] >= 0);
-    ALsizei NewDelay[2]{
-        HRTF_HISTORY_LENGTH - newparams->Delay[0],
-        HRTF_HISTORY_LENGTH - newparams->Delay[1] };
-    ASSUME(NewDelay[0] >= 0 && NewDelay[1] >= 0);
-
+    ASSUME(Delay[0] >= 0 && Delay[1] >= 0);
+    ALfloat stepcount{0.0f};
     for(ALsizei i{0};i < BufferSize;++i)
     {
-        ALfloat g{oldGain + oldGainStep*stepcount};
-        ALfloat left{InSamples[OldDelay[0]++] * g};
-        ALfloat right{InSamples[OldDelay[1]++] * g};
+        const ALfloat g{oldGain + oldGainStep*stepcount};
+        const ALfloat left{InSamples[Delay[0]++] * g};
+        const ALfloat right{InSamples[Delay[1]++] * g};
         ApplyCoeffs(i, AccumSamples+i, IrSize, OldCoeffs, left, right);
 
-        g = newGainStep*stepcount;
-        left = InSamples[NewDelay[0]++] * g;
-        right = InSamples[NewDelay[1]++] * g;
+        stepcount += 1.0f;
+    }
+
+    Delay[0] = HRTF_HISTORY_LENGTH - newparams->Delay[0];
+    Delay[1] = HRTF_HISTORY_LENGTH - newparams->Delay[1];
+    ASSUME(Delay[0] >= 0 && Delay[1] >= 0);
+    stepcount = 0.0f;
+    for(ALsizei i{0};i < BufferSize;++i)
+    {
+        const ALfloat g{newGainStep*stepcount};
+        const ALfloat left{InSamples[Delay[0]++] * g};
+        const ALfloat right{InSamples[Delay[1]++] * g};
         ApplyCoeffs(i, AccumSamples+i, IrSize, NewCoeffs, left, right);
 
         stepcount += 1.0f;
     }
+
     for(ALsizei i{0};i < BufferSize;++i)
         LeftOut[OutPos+i]  += AccumSamples[i][0];
     for(ALsizei i{0};i < BufferSize;++i)