1 files changed, 218 insertions, 0 deletions
diff --git a/core/mixer/mixer_c.cpp b/core/mixer/mixer_c.cpp
new file mode 100644
index 00000000..28a92ef7
--- /dev/null
+++ b/core/mixer/mixer_c.cpp
@@ -0,0 +1,218 @@
+#include "config.h"
+
+#include <cassert>
+#include <cmath>
+#include <limits>
+
+#include "alnumeric.h"
+#include "core/bsinc_defs.h"
+#include "core/cubic_defs.h"
+#include "defs.h"
+#include "hrtfbase.h"
+
+struct CTag;
+struct PointTag;
+struct LerpTag;
+struct CubicTag;
+struct BSincTag;
+struct FastBSincTag;
+
+
+namespace {
+
+constexpr uint BsincPhaseDiffBits{MixerFracBits - BSincPhaseBits};
+constexpr uint BsincPhaseDiffOne{1 << BsincPhaseDiffBits};
+constexpr uint BsincPhaseDiffMask{BsincPhaseDiffOne - 1u};
+
+constexpr uint CubicPhaseDiffBits{MixerFracBits - CubicPhaseBits};
+constexpr uint CubicPhaseDiffOne{1 << CubicPhaseDiffBits};
+constexpr uint CubicPhaseDiffMask{CubicPhaseDiffOne - 1u};
+
+inline float do_point(const InterpState&, const float *RESTRICT vals, const uint)
+{ return vals[0]; }
+inline float do_lerp(const InterpState&, const float *RESTRICT vals, const uint frac)
+{ return lerpf(vals[0], vals[1], static_cast<float>(frac)*(1.0f/MixerFracOne)); }
+inline float do_cubic(const InterpState &istate, const float *RESTRICT vals, const uint frac)
+{
+    /* Calculate the phase index and factor. */
+    const uint pi{frac >> CubicPhaseDiffBits};
+    const float pf{static_cast<float>(frac&CubicPhaseDiffMask) * (1.0f/CubicPhaseDiffOne)};
+
+    const float *RESTRICT fil{al::assume_aligned<16>(istate.cubic.filter[pi].mCoeffs)};
+    const float *RESTRICT phd{al::assume_aligned<16>(istate.cubic.filter[pi].mDeltas)};
+
+    /* Apply the phase interpolated filter. */
+    return (fil[0] + pf*phd[0])*vals[0] + (fil[1] + pf*phd[1])*vals[1]
+        + (fil[2] + pf*phd[2])*vals[2] + (fil[3] + pf*phd[3])*vals[3];
+}
+inline float do_bsinc(const InterpState &istate, const float *RESTRICT vals, const uint frac)
+{
+    const size_t m{istate.bsinc.m};
+    ASSUME(m > 0);
+
+    /* Calculate the phase index and factor. */
+    const uint pi{frac >> BsincPhaseDiffBits};
+    const float pf{static_cast<float>(frac&BsincPhaseDiffMask) * (1.0f/BsincPhaseDiffOne)};
+
+    const float *RESTRICT fil{istate.bsinc.filter + m*pi*2};
+    const float *RESTRICT phd{fil + m};
+    const float *RESTRICT scd{fil + BSincPhaseCount*2*m};
+    const float *RESTRICT spd{scd + m};
+
+    /* Apply the scale and phase interpolated filter. */
+    float r{0.0f};
+    for(size_t j_f{0};j_f < m;j_f++)
+        r += (fil[j_f] + istate.bsinc.sf*scd[j_f] + pf*(phd[j_f] + istate.bsinc.sf*spd[j_f])) * vals[j_f];
+    return r;
+}
+inline float do_fastbsinc(const InterpState &istate, const float *RESTRICT vals, const uint frac)
+{
+    const size_t m{istate.bsinc.m};
+    ASSUME(m > 0);
+
+    /* Calculate the phase index and factor. */
+    const uint pi{frac >> BsincPhaseDiffBits};
+    const float pf{static_cast<float>(frac&BsincPhaseDiffMask) * (1.0f/BsincPhaseDiffOne)};
+
+    const float *RESTRICT fil{istate.bsinc.filter + m*pi*2};
+    const float *RESTRICT phd{fil + m};
+
+    /* Apply the phase interpolated filter. */
+    float r{0.0f};
+    for(size_t j_f{0};j_f < m;j_f++)
+        r += (fil[j_f] + pf*phd[j_f]) * vals[j_f];
+    return r;
+}
+
+using SamplerT = float(&)(const InterpState&, const float*RESTRICT, const uint);
+template<SamplerT Sampler>
+void DoResample(const InterpState *state, const float *RESTRICT src, uint frac,
+    const uint increment, const al::span<float> dst)
+{
+    const InterpState istate{*state};
+    ASSUME(frac < MixerFracOne);
+    for(float &out : dst)
+    {
+        out = Sampler(istate, src, frac);
+
+        frac += increment;
+        src  += frac>>MixerFracBits;
+        frac &= MixerFracMask;
+    }
+}
+
+inline void ApplyCoeffs(float2 *RESTRICT Values, const size_t IrSize, const ConstHrirSpan Coeffs,
+    const float left, const float right)
+{
+    ASSUME(IrSize >= MinIrLength);
+    for(size_t c{0};c < IrSize;++c)
+    {
+        Values[c][0] += Coeffs[c][0] * left;
+        Values[c][1] += Coeffs[c][1] * right;
+    }
+}
+
+force_inline void MixLine(const al::span<const float> InSamples, float *RESTRICT dst,
+    float &CurrentGain, const float TargetGain, const float delta, const size_t min_len,
+    size_t Counter)
+{
+    float gain{CurrentGain};
+    const float step{(TargetGain-gain) * delta};
+
+    size_t pos{0};
+    if(!(std::abs(step) > std::numeric_limits<float>::epsilon()))
+        gain = TargetGain;
+    else
+    {
+        float step_count{0.0f};
+        for(;pos != min_len;++pos)
+        {
+            dst[pos] += InSamples[pos] * (gain + step*step_count);
+            step_count += 1.0f;
+        }
+        if(pos == Counter)
+            gain = TargetGain;
+        else
+            gain += step*step_count;
+    }
+    CurrentGain = gain;
+
+    if(!(std::abs(gain) > GainSilenceThreshold))
+        return;
+    for(;pos != InSamples.size();++pos)
+        dst[pos] += InSamples[pos] * gain;
+}
+
+} // namespace
+
+template<>
+void Resample_<PointTag,CTag>(const InterpState *state, const float *RESTRICT src, uint frac,
+    const uint increment, const al::span<float> dst)
+{ DoResample<do_point>(state, src, frac, increment, dst); }
+
+template<>
+void Resample_<LerpTag,CTag>(const InterpState *state, const float *RESTRICT src, uint frac,
+    const uint increment, const al::span<float> dst)
+{ DoResample<do_lerp>(state, src, frac, increment, dst); }
+
+template<>
+void Resample_<CubicTag,CTag>(const InterpState *state, const float *RESTRICT src, uint frac,
+    const uint increment, const al::span<float> dst)
+{ DoResample<do_cubic>(state, src-1, frac, increment, dst); }
+
+template<>
+void Resample_<BSincTag,CTag>(const InterpState *state, const float *RESTRICT src, uint frac,
+    const uint increment, const al::span<float> dst)
+{ DoResample<do_bsinc>(state, src-state->bsinc.l, frac, increment, dst); }
+
+template<>
+void Resample_<FastBSincTag,CTag>(const InterpState *state, const float *RESTRICT src, uint frac,
+    const uint increment, const al::span<float> dst)
+{ DoResample<do_fastbsinc>(state, src-state->bsinc.l, frac, increment, dst); }
+
+
+template<>
+void MixHrtf_<CTag>(const float *InSamples, float2 *AccumSamples, const uint IrSize,
+    const MixHrtfFilter *hrtfparams, const size_t BufferSize)
+{ MixHrtfBase<ApplyCoeffs>(InSamples, AccumSamples, IrSize, hrtfparams, BufferSize); }
+
+template<>
+void MixHrtfBlend_<CTag>(const float *InSamples, float2 *AccumSamples, const uint IrSize,
+    const HrtfFilter *oldparams, const MixHrtfFilter *newparams, const size_t BufferSize)
+{
+    MixHrtfBlendBase<ApplyCoeffs>(InSamples, AccumSamples, IrSize, oldparams, newparams,
+        BufferSize);
+}
+
+template<>
+void MixDirectHrtf_<CTag>(const FloatBufferSpan LeftOut, const FloatBufferSpan RightOut,
+    const al::span<const FloatBufferLine> InSamples, float2 *AccumSamples,
+    float *TempBuf, HrtfChannelState *ChanState, const size_t IrSize, const size_t BufferSize)
+{
+    MixDirectHrtfBase<ApplyCoeffs>(LeftOut, RightOut, InSamples, AccumSamples, TempBuf, ChanState,
+        IrSize, BufferSize);
+}
+
+
+template<>
+void Mix_<CTag>(const al::span<const float> InSamples, const al::span<FloatBufferLine> OutBuffer,
+    float *CurrentGains, const float *TargetGains, const size_t Counter, const size_t OutPos)
+{
+    const float delta{(Counter > 0) ? 1.0f / static_cast<float>(Counter) : 0.0f};
+    const auto min_len = minz(Counter, InSamples.size());
+
+    for(FloatBufferLine &output : OutBuffer)
+        MixLine(InSamples, al::assume_aligned<16>(output.data()+OutPos), *CurrentGains++,
+            *TargetGains++, delta, min_len, Counter);
+}
+
+template<>
+void Mix_<CTag>(const al::span<const float> InSamples, float *OutBuffer, float &CurrentGain,
+    const float TargetGain, const size_t Counter)
+{
+    const float delta{(Counter > 0) ? 1.0f / static_cast<float>(Counter) : 0.0f};
+    const auto min_len = minz(Counter, InSamples.size());
+
+    MixLine(InSamples, al::assume_aligned<16>(OutBuffer), CurrentGain,
+        TargetGain, delta, min_len, Counter);
+}