Move the mixer functions to core

1 files changed, 198 insertions, 0 deletions

diff --git a/core/mixer/mixer_c.cpp b/core/mixer/mixer_c.cpp
new file mode 100644
index 00000000..24ccd175
--- /dev/null
+++ b/core/mixer/mixer_c.cpp
@@ -0,0 +1,198 @@
+#include "config.h"
+
+#include <cassert>
+#include <cmath>
+#include <limits>
+
+#include "alnumeric.h"
+#include "core/bsinc_tables.h"
+#include "defs.h"
+#include "hrtfbase.h"
+
+struct CTag;
+struct CopyTag;
+struct PointTag;
+struct LerpTag;
+struct CubicTag;
+struct BSincTag;
+struct FastBSincTag;
+
+
+namespace {
+
+constexpr uint FracPhaseBitDiff{MixerFracBits - BSincPhaseBits};
+constexpr uint FracPhaseDiffOne{1 << FracPhaseBitDiff};
+
+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 lerp(vals[0], vals[1], static_cast<float>(frac)*(1.0f/MixerFracOne)); }
+inline float do_cubic(const InterpState&, const float *RESTRICT vals, const uint frac)
+{ return cubic(vals[0], vals[1], vals[2], vals[3], static_cast<float>(frac)*(1.0f/MixerFracOne)); }
+inline float do_bsinc(const InterpState &istate, const float *RESTRICT vals, const uint frac)
+{
+    const size_t m{istate.bsinc.m};
+
+    // Calculate the phase index and factor.
+    const uint pi{frac >> FracPhaseBitDiff};
+    const float pf{static_cast<float>(frac & (FracPhaseDiffOne-1)) * (1.0f/FracPhaseDiffOne)};
+
+    const float *fil{istate.bsinc.filter + m*pi*4};
+    const float *phd{fil + m};
+    const float *scd{phd + m};
+    const float *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};
+
+    // Calculate the phase index and factor.
+    const uint pi{frac >> FracPhaseBitDiff};
+    const float pf{static_cast<float>(frac & (FracPhaseDiffOne-1)) * (1.0f/FracPhaseDiffOne)};
+
+    const float *fil{istate.bsinc.filter + m*pi*4};
+    const float *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>
+const float *DoResample(const InterpState *state, const float *RESTRICT src, uint frac,
+    uint increment, const al::span<float> dst)
+{
+    const InterpState istate{*state};
+    for(float &out : dst)
+    {
+        out = Sampler(istate, src, frac);
+
+        frac += increment;
+        src  += frac>>MixerFracBits;
+        frac &= MixerFracMask;
+    }
+    return dst.data();
+}
+
+inline void ApplyCoeffs(float2 *RESTRICT Values, const uint_fast32_t IrSize,
+    const HrirArray &Coeffs, const float left, const float right)
+{
+    ASSUME(IrSize >= MIN_IR_LENGTH);
+    for(size_t c{0};c < IrSize;++c)
+    {
+        Values[c][0] += Coeffs[c][0] * left;
+        Values[c][1] += Coeffs[c][1] * right;
+    }
+}
+
+} // namespace
+
+template<>
+const float *Resample_<CopyTag,CTag>(const InterpState*, const float *RESTRICT src, uint, uint,
+    const al::span<float> dst)
+{
+#if defined(HAVE_SSE) || defined(HAVE_NEON)
+    /* Avoid copying the source data if it's aligned like the destination. */
+    if((reinterpret_cast<intptr_t>(src)&15) == (reinterpret_cast<intptr_t>(dst.data())&15))
+        return src;
+#endif
+    std::copy_n(src, dst.size(), dst.begin());
+    return dst.data();
+}
+
+template<>
+const float *Resample_<PointTag,CTag>(const InterpState *state, const float *RESTRICT src,
+    uint frac, uint increment, const al::span<float> dst)
+{ return DoResample<do_point>(state, src, frac, increment, dst); }
+
+template<>
+const float *Resample_<LerpTag,CTag>(const InterpState *state, const float *RESTRICT src,
+    uint frac, uint increment, const al::span<float> dst)
+{ return DoResample<do_lerp>(state, src, frac, increment, dst); }
+
+template<>
+const float *Resample_<CubicTag,CTag>(const InterpState *state, const float *RESTRICT src,
+    uint frac, uint increment, const al::span<float> dst)
+{ return DoResample<do_cubic>(state, src-1, frac, increment, dst); }
+
+template<>
+const float *Resample_<BSincTag,CTag>(const InterpState *state, const float *RESTRICT src,
+    uint frac, uint increment, const al::span<float> dst)
+{ return DoResample<do_bsinc>(state, src-state->bsinc.l, frac, increment, dst); }
+
+template<>
+const float *Resample_<FastBSincTag,CTag>(const InterpState *state, const float *RESTRICT src,
+    uint frac, uint increment, const al::span<float> dst)
+{ return 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>(FloatBufferLine &LeftOut, FloatBufferLine &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)
+    {
+        float *RESTRICT dst{al::assume_aligned<16>(output.data()+OutPos)};
+        float gain{*CurrentGains};
+        const float step{(*TargetGains-gain) * delta};
+
+        size_t pos{0};
+        if(!(std::abs(step) > std::numeric_limits<float>::epsilon()))
+            gain = *TargetGains;
+        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 = *TargetGains;
+            else
+                gain += step*step_count;
+        }
+        *CurrentGains = gain;
+        ++CurrentGains;
+        ++TargetGains;
+
+        if(!(std::abs(gain) > GainSilenceThreshold))
+            continue;
+        for(;pos != InSamples.size();++pos)
+            dst[pos] += InSamples[pos] * gain;
+    }
+}