Rename Alc to alc

1 files changed, 115 insertions, 0 deletions

diff --git a/alc/filters/splitter.cpp b/alc/filters/splitter.cpp
new file mode 100644
index 00000000..09e7bfe8
--- /dev/null
+++ b/alc/filters/splitter.cpp
@@ -0,0 +1,115 @@
+
+#include "config.h"
+
+#include "splitter.h"
+
+#include <cmath>
+#include <limits>
+#include <algorithm>
+
+#include "math_defs.h"
+
+template<typename Real>
+void BandSplitterR<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;
+
+    lp_z1 = 0.0f;
+    lp_z2 = 0.0f;
+    ap_z1 = 0.0f;
+}
+
+template<typename Real>
+void BandSplitterR<Real>::process(Real *hpout, Real *lpout, const Real *input, const int count)
+{
+    ASSUME(count > 0);
+
+    const Real ap_coeff{this->coeff};
+    const Real lp_coeff{this->coeff*0.5f + 0.5f};
+    Real lp_z1{this->lp_z1};
+    Real lp_z2{this->lp_z2};
+    Real ap_z1{this->ap_z1};
+    auto proc_sample = [ap_coeff,lp_coeff,&lp_z1,&lp_z2,&ap_z1,&lpout](const Real in) noexcept -> Real
+    {
+        /* Low-pass sample processing. */
+        Real d{(in - lp_z1) * lp_coeff};
+        Real lp_y{lp_z1 + d};
+        lp_z1 = lp_y + d;
+
+        d = (lp_y - lp_z2) * lp_coeff;
+        lp_y = lp_z2 + d;
+        lp_z2 = lp_y + d;
+
+        *(lpout++) = lp_y;
+
+        /* All-pass sample processing. */
+        Real ap_y{in*ap_coeff + ap_z1};
+        ap_z1 = in - ap_y*ap_coeff;
+
+        /* High-pass generated from removing low-passed output. */
+        return ap_y - lp_y;
+    };
+    std::transform(input, input+count, hpout, proc_sample);
+    this->lp_z1 = lp_z1;
+    this->lp_z2 = lp_z2;
+    this->ap_z1 = ap_z1;
+}
+
+template<typename Real>
+void BandSplitterR<Real>::applyHfScale(Real *samples, const Real hfscale, const int count)
+{
+    ASSUME(count > 0);
+
+    const Real ap_coeff{this->coeff};
+    const Real lp_coeff{this->coeff*0.5f + 0.5f};
+    Real lp_z1{this->lp_z1};
+    Real lp_z2{this->lp_z2};
+    Real ap_z1{this->ap_z1};
+    auto proc_sample = [hfscale,ap_coeff,lp_coeff,&lp_z1,&lp_z2,&ap_z1](const Real in) noexcept -> Real
+    {
+        /* Low-pass sample processing. */
+        Real d{(in - lp_z1) * lp_coeff};
+        Real lp_y{lp_z1 + d};
+        lp_z1 = lp_y + d;
+
+        d = (lp_y - lp_z2) * lp_coeff;
+        lp_y = lp_z2 + d;
+        lp_z2 = lp_y + d;
+
+        /* All-pass sample processing. */
+        Real ap_y{in*ap_coeff + ap_z1};
+        ap_z1 = in - ap_y*ap_coeff;
+
+        /* High-pass generated from removing low-passed output. */
+        return (ap_y-lp_y)*hfscale + lp_y;
+    };
+    std::transform(samples, samples+count, samples, proc_sample);
+    this->lp_z1 = lp_z1;
+    this->lp_z2 = lp_z2;
+    this->ap_z1 = ap_z1;
+}
+
+template<typename Real>
+void BandSplitterR<Real>::applyAllpass(Real *samples, const int count) const
+{
+    ASSUME(count > 0);
+
+    const Real coeff{this->coeff};
+    Real z1{0.0f};
+    auto proc_sample = [coeff,&z1](const Real in) noexcept -> Real
+    {
+        const Real out{in*coeff + z1};
+        z1 = in - out*coeff;
+        return out;
+    };
+    std::transform(samples, samples+count, samples, proc_sample);
+}
+
+
+template class BandSplitterR<float>;
+template class BandSplitterR<double>;