1 files changed, 138 insertions, 0 deletions
diff --git a/alc/mixer/hrtfbase.h b/alc/mixer/hrtfbase.h
new file mode 100644
index 00000000..a76bd62e
--- /dev/null
+++ b/alc/mixer/hrtfbase.h
@@ -0,0 +1,138 @@
+#ifndef MIXER_HRTFBASE_H
+#define MIXER_HRTFBASE_H
+
+#include <algorithm>
+
+#include "alu.h"
+#include "../hrtf.h"
+#include "opthelpers.h"
+
+
+using ApplyCoeffsT = void(ALsizei Offset, float2 *RESTRICT Values, const ALsizei irSize,
+    const HrirArray<ALfloat> &Coeffs, const ALfloat left, const ALfloat right);
+
+template<ApplyCoeffsT &ApplyCoeffs>
+inline void MixHrtfBase(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
+    const ALfloat *InSamples, float2 *RESTRICT AccumSamples, const ALsizei OutPos,
+    const ALsizei IrSize, MixHrtfFilter *hrtfparams, const ALsizei BufferSize)
+{
+    ASSUME(OutPos >= 0);
+    ASSUME(IrSize >= 4);
+    ASSUME(BufferSize > 0);
+
+    const auto &Coeffs = *hrtfparams->Coeffs;
+    const ALfloat gainstep{hrtfparams->GainStep};
+    const ALfloat gain{hrtfparams->Gain};
+
+    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};
+        const ALfloat left{InSamples[Delay[0]++] * g};
+        const ALfloat right{InSamples[Delay[1]++] * g};
+        ApplyCoeffs(i, AccumSamples+i, IrSize, Coeffs, 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)
+        RightOut[OutPos+i] += AccumSamples[i][1];
+
+    hrtfparams->Gain = gain + gainstep*stepcount;
+}
+
+template<ApplyCoeffsT &ApplyCoeffs>
+inline void MixHrtfBlendBase(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
+    const ALfloat *InSamples, float2 *RESTRICT AccumSamples, const ALsizei OutPos,
+    const ALsizei IrSize, const HrtfFilter *oldparams, MixHrtfFilter *newparams,
+    const ALsizei BufferSize)
+{
+    const auto &OldCoeffs = oldparams->Coeffs;
+    const ALfloat oldGain{oldparams->Gain};
+    const ALfloat oldGainStep{-oldGain / static_cast<ALfloat>(BufferSize)};
+    const auto &NewCoeffs = *newparams->Coeffs;
+    const ALfloat newGainStep{newparams->GainStep};
+
+    ASSUME(OutPos >= 0);
+    ASSUME(IrSize >= 4);
+    ASSUME(BufferSize > 0);
+
+    ALsizei Delay[2]{
+        HRTF_HISTORY_LENGTH - oldparams->Delay[0],
+        HRTF_HISTORY_LENGTH - oldparams->Delay[1] };
+    ASSUME(Delay[0] >= 0 && Delay[1] >= 0);
+    ALfloat stepcount{0.0f};
+    for(ALsizei i{0};i < BufferSize;++i)
+    {
+        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);
+
+        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)
+        RightOut[OutPos+i] += AccumSamples[i][1];
+
+    newparams->Gain = newGainStep*stepcount;
+}
+
+template<ApplyCoeffsT &ApplyCoeffs>
+inline void MixDirectHrtfBase(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
+    const al::span<const FloatBufferLine> InSamples, float2 *RESTRICT AccumSamples,
+    DirectHrtfState *State, const ALsizei BufferSize)
+{
+    ASSUME(BufferSize > 0);
+
+    const ALsizei IrSize{State->IrSize};
+    ASSUME(IrSize >= 4);
+
+    auto chanstate = State->Chan.begin();
+    for(const FloatBufferLine &input : InSamples)
+    {
+        const auto &Coeffs = chanstate->Coeffs;
+
+        auto accum_iter = std::copy_n(chanstate->Values.begin(),
+            chanstate->Values.size(), AccumSamples);
+        std::fill_n(accum_iter, BufferSize, float2{});
+
+        for(ALsizei i{0};i < BufferSize;++i)
+        {
+            const ALfloat insample{input[i]};
+            ApplyCoeffs(i, AccumSamples+i, IrSize, Coeffs, insample, insample);
+        }
+        for(ALsizei i{0};i < BufferSize;++i)
+            LeftOut[i]  += AccumSamples[i][0];
+        for(ALsizei i{0};i < BufferSize;++i)
+            RightOut[i] += AccumSamples[i][1];
+
+        std::copy_n(AccumSamples + BufferSize, chanstate->Values.size(),
+            chanstate->Values.begin());
+        ++chanstate;
+    }
+}
+
+#endif /* MIXER_HRTFBASE_H */