Avoid a separate struct for the bandsplitter all-pass

5 files changed, 17 insertions, 58 deletions

diff --git a/Alc/alu.cpp b/Alc/alu.cpp
index d41a66aa..97ebf0cb 100644
--- a/Alc/alu.cpp
+++ b/Alc/alu.cpp
@@ -1499,7 +1499,6 @@ void ApplyStablizer(FrontStablizer *Stablizer, FloatBufferLine *Buffer, const in
         }
     }
 
-    const SplitterAllpass &APFilter = Stablizer->APFilter;
     ALfloat (&lsplit)[2][BUFFERSIZE] = Stablizer->LSplit;
     ALfloat (&rsplit)[2][BUFFERSIZE] = Stablizer->RSplit;
     auto &tmpbuf = Stablizer->TempBuf;
@@ -1507,7 +1506,7 @@ void ApplyStablizer(FrontStablizer *Stablizer, FloatBufferLine *Buffer, const in
     /* This applies the band-splitter, preserving phase at the cost of some
      * delay. The shorter the delay, the more error seeps into the result.
      */
-    auto apply_splitter = [&APFilter,&tmpbuf,SamplesToDo](const FloatBufferLine &Buffer,
+    auto apply_splitter = [&tmpbuf,SamplesToDo](const FloatBufferLine &Buffer,
         ALfloat (&DelayBuf)[FrontStablizer::DelayLength], BandSplitter &Filter,
         ALfloat (&splitbuf)[2][BUFFERSIZE]) -> void
     {
@@ -1522,13 +1521,9 @@ void ApplyStablizer(FrontStablizer *Stablizer, FloatBufferLine *Buffer, const in
         std::copy_n(std::begin(tmpbuf), FrontStablizer::DelayLength, std::begin(DelayBuf));
 
         /* Apply an all-pass on the reversed signal, then reverse the samples
-         * to get the forward signal with a reversed phase shift. Note that the
-         * all-pass filter is copied to a local for use, since each pass is
-         * indepedent because the signal's processed backwards (with a delay
-         * being used to hide discontinuities).
+         * to get the forward signal with a reversed phase shift.
          */
-        SplitterAllpass allpass{APFilter};
-        allpass.process(tmpbuf, SamplesToDo+FrontStablizer::DelayLength);
+        Filter.applyAllpass(tmpbuf, SamplesToDo+FrontStablizer::DelayLength);
         std::reverse(std::begin(tmpbuf), tmpbuf_end+FrontStablizer::DelayLength);
 
         /* Now apply the band-splitter, combining its phase shift with the
diff --git a/Alc/filters/splitter.cpp b/Alc/filters/splitter.cpp
index 8b1a4db4..09e7bfe8 100644
--- a/Alc/filters/splitter.cpp
+++ b/Alc/filters/splitter.cpp
@@ -94,30 +94,13 @@ void BandSplitterR<Real>::applyHfScale(Real *samples, const Real hfscale, const
     this->ap_z1 = ap_z1;
 }
 
-template class BandSplitterR<float>;
-template class BandSplitterR<double>;
-
-
-template<typename Real>
-void SplitterAllpassR<Real>::init(Real f0norm)
-{
-    const Real w{f0norm * al::MathDefs<Real>::Tau()};
-    const Real cw{std::cos(w)};
-    if(cw > std::numeric_limits<float>::epsilon())
-        coeff = (std::sin(w) - 1.0f) / cw;
-    else
-        coeff = cw * -0.5f;
-
-    z1 = 0.0f;
-}
-
 template<typename Real>
-void SplitterAllpassR<Real>::process(Real *samples, int count)
+void BandSplitterR<Real>::applyAllpass(Real *samples, const int count) const
 {
     ASSUME(count > 0);
 
     const Real coeff{this->coeff};
-    Real z1{this->z1};
+    Real z1{0.0f};
     auto proc_sample = [coeff,&z1](const Real in) noexcept -> Real
     {
         const Real out{in*coeff + z1};
@@ -125,8 +108,8 @@ void SplitterAllpassR<Real>::process(Real *samples, int count)
         return out;
     };
     std::transform(samples, samples+count, samples, proc_sample);
-    this->z1 = z1;
 }
 
-template class SplitterAllpassR<float>;
-template class SplitterAllpassR<double>;
+
+template class BandSplitterR<float>;
+template class BandSplitterR<double>;
diff --git a/Alc/filters/splitter.h b/Alc/filters/splitter.h
index cd5fe864..70fddd9e 100644
--- a/Alc/filters/splitter.h
+++ b/Alc/filters/splitter.h
@@ -21,28 +21,16 @@ public:
     void init(Real f0norm);
     void clear() noexcept { lp_z1 = lp_z2 = ap_z1 = 0.0f; }
     void process(Real *hpout, Real *lpout, const Real *input, const int count);
-    void applyHfScale(Real *samples, const Real hfscale, const int count);
-};
-using BandSplitter = BandSplitterR<float>;
-
-/* The all-pass portion of the band splitter. Applies the same phase shift
- * without splitting the signal.
- */
-template<typename Real>
-class SplitterAllpassR {
-    Real coeff{0.0f};
-    Real z1{0.0f};
 
-public:
-    SplitterAllpassR() = default;
-    SplitterAllpassR(const SplitterAllpassR&) = default;
-    SplitterAllpassR(Real f0norm) { init(f0norm); }
+    void applyHfScale(Real *samples, const Real hfscale, const int count);
 
-    void init(Real f0norm);
-    void clear() noexcept { z1 = 0.0f; }
-    void process(Real *samples, int count);
+    /* The all-pass portion of the band splitter. Applies the same phase shift
+     * without splitting the signal. Note that each use of this method is
+     * indepedent, it does not track history between calls.
+     */
+    void applyAllpass(Real *samples, const int count) const;
 };
-using SplitterAllpass = SplitterAllpassR<float>;
+using BandSplitter = BandSplitterR<float>;
 
 
 struct FrontStablizer {
@@ -50,7 +38,6 @@ struct FrontStablizer {
 
     alignas(16) float DelayBuf[MAX_OUTPUT_CHANNELS][DelayLength];
 
-    SplitterAllpass APFilter;
     BandSplitter LFilter, RFilter;
     alignas(16) float LSplit[2][BUFFERSIZE];
     alignas(16) float RSplit[2][BUFFERSIZE];
diff --git a/Alc/hrtf.cpp b/Alc/hrtf.cpp
index 16b2dc3c..0980dcb6 100644
--- a/Alc/hrtf.cpp
+++ b/Alc/hrtf.cpp
@@ -338,7 +338,6 @@ void BuildBFormatHrtf(const HrtfEntry *Hrtf, DirectHrtfState *state, const ALsiz
     static constexpr ALsizei base_delay{DualBand ? 12 : 0};
     const ALdouble xover_norm{400.0 / Hrtf->sampleRate};
     BandSplitterR<double> splitter{xover_norm};
-    SplitterAllpassR<double> allpass{xover_norm};
 
     auto tmpres = al::vector<HrirArray<ALdouble>>(NumChannels);
     auto tmpfilt = al::vector<std::array<ALdouble,HRIR_LENGTH*4>>(3);
@@ -381,8 +380,7 @@ void BuildBFormatHrtf(const HrtfEntry *Hrtf, DirectHrtfState *state, const ALsiz
          * sample array. This produces the forward response with a backwards
          * phase-shift (+n degrees becomes -n degrees).
          */
-        allpass.clear();
-        allpass.process(tmpfilt[2].data(), static_cast<int>(tmpfilt[2].size()));
+        splitter.applyAllpass(tmpfilt[2].data(), static_cast<int>(tmpfilt[2].size()));
         std::reverse(tmpfilt[2].begin(), tmpfilt[2].end());
 
         /* Now apply the band-splitter. This applies the normal phase-shift,
@@ -408,8 +406,7 @@ void BuildBFormatHrtf(const HrtfEntry *Hrtf, DirectHrtfState *state, const ALsiz
         std::transform(fir, fir+Hrtf->irSize, tmpfilt[2].rbegin() + HRIR_LENGTH*3,
             [](const ALfloat (&ir)[2]) noexcept -> ALdouble { return ir[1]; });
 
-        allpass.clear();
-        allpass.process(tmpfilt[2].data(), static_cast<int>(tmpfilt[2].size()));
+        splitter.applyAllpass(tmpfilt[2].data(), static_cast<int>(tmpfilt[2].size()));
         std::reverse(tmpfilt[2].begin(), tmpfilt[2].end());
 
         splitter.clear();
diff --git a/Alc/panning.cpp b/Alc/panning.cpp
index ab57ed45..87f8bf72 100644
--- a/Alc/panning.cpp
+++ b/Alc/panning.cpp
@@ -841,9 +841,6 @@ void aluInitRenderer(ALCdevice *device, ALint hrtf_id, HrtfRequestMode hrtf_appr
                 stablizer->LFilter.init(scale);
                 stablizer->RFilter = stablizer->LFilter;
 
-                /* Initialize an all-pass filter for the phase corrector. */
-                stablizer->APFilter.init(scale);
-
                 device->Stablizer = std::move(stablizer);
                 /* NOTE: Don't know why this has to be "copied" into a local
                  * static constexpr variable to avoid a reference on