1 files changed, 208 insertions, 0 deletions
diff --git a/alc/mixer/mixer_c.cpp b/alc/mixer/mixer_c.cpp
new file mode 100644
index 00000000..47c4a6f4
--- /dev/null
+++ b/alc/mixer/mixer_c.cpp
@@ -0,0 +1,208 @@
+#include "config.h"
+
+#include <cassert>
+
+#include <limits>
+
+#include "alcmain.h"
+#include "alu.h"
+#include "alSource.h"
+#include "alAuxEffectSlot.h"
+#include "defs.h"
+#include "hrtfbase.h"
+
+
+namespace {
+
+inline ALfloat do_point(const InterpState&, const ALfloat *RESTRICT vals, const ALsizei)
+{ return vals[0]; }
+inline ALfloat do_lerp(const InterpState&, const ALfloat *RESTRICT vals, const ALsizei frac)
+{ return lerp(vals[0], vals[1], frac * (1.0f/FRACTIONONE)); }
+inline ALfloat do_cubic(const InterpState&, const ALfloat *RESTRICT vals, const ALsizei frac)
+{ return cubic(vals[0], vals[1], vals[2], vals[3], frac * (1.0f/FRACTIONONE)); }
+inline ALfloat do_bsinc(const InterpState &istate, const ALfloat *RESTRICT vals, const ALsizei frac)
+{
+    ASSUME(istate.bsinc.m > 0);
+
+    // Calculate the phase index and factor.
+#define FRAC_PHASE_BITDIFF (FRACTIONBITS-BSINC_PHASE_BITS)
+    const ALsizei pi{frac >> FRAC_PHASE_BITDIFF};
+    const ALfloat pf{(frac & ((1<<FRAC_PHASE_BITDIFF)-1)) * (1.0f/(1<<FRAC_PHASE_BITDIFF))};
+#undef FRAC_PHASE_BITDIFF
+
+    const ALfloat *fil{istate.bsinc.filter + istate.bsinc.m*pi*4};
+    const ALfloat *scd{fil + istate.bsinc.m};
+    const ALfloat *phd{scd + istate.bsinc.m};
+    const ALfloat *spd{phd + istate.bsinc.m};
+
+    // Apply the scale and phase interpolated filter.
+    ALfloat r{0.0f};
+    for(ALsizei j_f{0};j_f < istate.bsinc.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;
+}
+
+using SamplerT = ALfloat(const InterpState&, const ALfloat*RESTRICT, const ALsizei);
+template<SamplerT &Sampler>
+const ALfloat *DoResample(const InterpState *state, const ALfloat *RESTRICT src,
+    ALsizei frac, ALint increment, ALfloat *RESTRICT dst, ALsizei numsamples)
+{
+    ASSUME(numsamples > 0);
+    ASSUME(increment > 0);
+    ASSUME(frac >= 0);
+
+    const InterpState istate{*state};
+    auto proc_sample = [&src,&frac,istate,increment]() -> ALfloat
+    {
+        const ALfloat ret{Sampler(istate, src, frac)};
+
+        frac += increment;
+        src  += frac>>FRACTIONBITS;
+        frac &= FRACTIONMASK;
+
+        return ret;
+    };
+    std::generate_n(dst, numsamples, proc_sample);
+
+    return dst;
+}
+
+} // namespace
+
+template<>
+const ALfloat *Resample_<CopyTag,CTag>(const InterpState*, const ALfloat *RESTRICT src, ALsizei,
+    ALint, ALfloat *RESTRICT dst, ALsizei dstlen)
+{
+    ASSUME(dstlen > 0);
+#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)&15))
+        return src;
+#endif
+    std::copy_n(src, dstlen, dst);
+    return dst;
+}
+
+template<>
+const ALfloat *Resample_<PointTag,CTag>(const InterpState *state, const ALfloat *RESTRICT src,
+    ALsizei frac, ALint increment, ALfloat *RESTRICT dst, ALsizei dstlen)
+{ return DoResample<do_point>(state, src, frac, increment, dst, dstlen); }
+
+template<>
+const ALfloat *Resample_<LerpTag,CTag>(const InterpState *state, const ALfloat *RESTRICT src,
+    ALsizei frac, ALint increment, ALfloat *RESTRICT dst, ALsizei dstlen)
+{ return DoResample<do_lerp>(state, src, frac, increment, dst, dstlen); }
+
+template<>
+const ALfloat *Resample_<CubicTag,CTag>(const InterpState *state, const ALfloat *RESTRICT src,
+    ALsizei frac, ALint increment, ALfloat *RESTRICT dst, ALsizei dstlen)
+{ return DoResample<do_cubic>(state, src-1, frac, increment, dst, dstlen); }
+
+template<>
+const ALfloat *Resample_<BSincTag,CTag>(const InterpState *state, const ALfloat *RESTRICT src,
+    ALsizei frac, ALint increment, ALfloat *RESTRICT dst, ALsizei dstlen)
+{ return DoResample<do_bsinc>(state, src-state->bsinc.l, frac, increment, dst, dstlen); }
+
+
+static inline void ApplyCoeffs(ALsizei /*Offset*/, float2 *RESTRICT Values, const ALsizei IrSize,
+    const HrirArray<ALfloat> &Coeffs, const ALfloat left, const ALfloat right)
+{
+    ASSUME(IrSize >= 2);
+    for(ALsizei c{0};c < IrSize;++c)
+    {
+        Values[c][0] += Coeffs[c][0] * left;
+        Values[c][1] += Coeffs[c][1] * right;
+    }
+}
+
+template<>
+void MixHrtf_<CTag>(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
+    const ALfloat *InSamples, float2 *AccumSamples, const ALsizei OutPos, const ALsizei IrSize,
+    MixHrtfFilter *hrtfparams, const ALsizei BufferSize)
+{
+    MixHrtfBase<ApplyCoeffs>(LeftOut, RightOut, InSamples, AccumSamples, OutPos, IrSize,
+        hrtfparams, BufferSize);
+}
+
+template<>
+void MixHrtfBlend_<CTag>(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
+    const ALfloat *InSamples, float2 *AccumSamples, const ALsizei OutPos, const ALsizei IrSize,
+    const HrtfFilter *oldparams, MixHrtfFilter *newparams, const ALsizei BufferSize)
+{
+    MixHrtfBlendBase<ApplyCoeffs>(LeftOut, RightOut, InSamples, AccumSamples, OutPos, IrSize,
+        oldparams, newparams, BufferSize);
+}
+
+template<>
+void MixDirectHrtf_<CTag>(FloatBufferLine &LeftOut, FloatBufferLine &RightOut,
+    const al::span<const FloatBufferLine> InSamples, float2 *AccumSamples, DirectHrtfState *State,
+    const ALsizei BufferSize)
+{
+    MixDirectHrtfBase<ApplyCoeffs>(LeftOut, RightOut, InSamples, AccumSamples, State, BufferSize);
+}
+
+
+template<>
+void Mix_<CTag>(const ALfloat *data, const al::span<FloatBufferLine> OutBuffer,
+    ALfloat *CurrentGains, const ALfloat *TargetGains, const ALsizei Counter, const ALsizei OutPos,
+    const ALsizei BufferSize)
+{
+    ASSUME(BufferSize > 0);
+
+    const ALfloat delta{(Counter > 0) ? 1.0f / static_cast<ALfloat>(Counter) : 0.0f};
+    for(FloatBufferLine &output : OutBuffer)
+    {
+        ALfloat *RESTRICT dst{output.data()+OutPos};
+        ALfloat gain{*CurrentGains};
+        const ALfloat diff{*TargetGains - gain};
+
+        ALsizei pos{0};
+        if(std::fabs(diff) > std::numeric_limits<float>::epsilon())
+        {
+            ALsizei minsize{mini(BufferSize, Counter)};
+            const ALfloat step{diff * delta};
+            ALfloat step_count{0.0f};
+            for(;pos < minsize;pos++)
+            {
+                dst[pos] += data[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::fabs(gain) > GAIN_SILENCE_THRESHOLD))
+            continue;
+        for(;pos < BufferSize;pos++)
+            dst[pos] += data[pos]*gain;
+    }
+}
+
+/* Basically the inverse of the above. Rather than one input going to multiple
+ * outputs (each with its own gain), it's multiple inputs (each with its own
+ * gain) going to one output. This applies one row (vs one column) of a matrix
+ * transform. And as the matrices are more or less static once set up, no
+ * stepping is necessary.
+ */
+template<>
+void MixRow_<CTag>(FloatBufferLine &OutBuffer, const ALfloat *Gains,
+    const al::span<const FloatBufferLine> InSamples, const ALsizei InPos, const ALsizei BufferSize)
+{
+    ASSUME(BufferSize > 0);
+
+    for(const FloatBufferLine &input : InSamples)
+    {
+        const ALfloat *RESTRICT src{input.data()+InPos};
+        const ALfloat gain{*(Gains++)};
+        if(!(std::fabs(gain) > GAIN_SILENCE_THRESHOLD))
+            continue;
+
+        for(ALsizei i{0};i < BufferSize;i++)
+            OutBuffer[i] += src[i] * gain;
+    }
+}