Use a span for the band-splitter input

2 files changed, 14 insertions, 16 deletions

diff --git a/alc/filters/splitter.cpp b/alc/filters/splitter.cpp
index c6218e70..e8e01802 100644
--- a/alc/filters/splitter.cpp
+++ b/alc/filters/splitter.cpp
@@ -27,10 +27,8 @@ void BandSplitterR<Real>::init(Real f0norm)
 }
 
 template<typename Real>
-void BandSplitterR<Real>::process(Real *hpout, Real *lpout, const Real *input, const size_t count)
+void BandSplitterR<Real>::process(const al::span<const Real> input, Real *hpout, Real *lpout)
 {
-    ASSUME(count > 0);
-
     const Real ap_coeff{mCoeff};
     const Real lp_coeff{mCoeff*0.5f + 0.5f};
     Real lp_z1{mLpZ1};
@@ -56,17 +54,15 @@ void BandSplitterR<Real>::process(Real *hpout, Real *lpout, const Real *input, c
         /* High-pass generated from removing low-passed output. */
         return ap_y - lp_y;
     };
-    std::transform(input, input+count, hpout, proc_sample);
+    std::transform(input.cbegin(), input.cend(), hpout, proc_sample);
     mLpZ1 = lp_z1;
     mLpZ2 = lp_z2;
     mApZ1 = ap_z1;
 }
 
 template<typename Real>
-void BandSplitterR<Real>::applyHfScale(Real *samples, const Real hfscale, const size_t count)
+void BandSplitterR<Real>::applyHfScale(const al::span<Real> samples, const Real hfscale)
 {
-    ASSUME(count > 0);
-
     const Real ap_coeff{mCoeff};
     const Real lp_coeff{mCoeff*0.5f + 0.5f};
     Real lp_z1{mLpZ1};
@@ -87,20 +83,20 @@ void BandSplitterR<Real>::applyHfScale(Real *samples, const Real hfscale, const
         Real ap_y{in*ap_coeff + ap_z1};
         ap_z1 = in - ap_y*ap_coeff;
 
-        /* High-pass generated from removing low-passed output. */
+        /* High-pass generated by removing the low-passed signal, which is then
+         * scaled and added back to the low-passed signal.
+         */
         return (ap_y-lp_y)*hfscale + lp_y;
     };
-    std::transform(samples, samples+count, samples, proc_sample);
+    std::transform(samples.begin(), samples.end(), samples.begin(), proc_sample);
     mLpZ1 = lp_z1;
     mLpZ2 = lp_z2;
     mApZ1 = ap_z1;
 }
 
 template<typename Real>
-void BandSplitterR<Real>::applyAllpass(Real *samples, const size_t count) const
+void BandSplitterR<Real>::applyAllpass(const al::span<Real> samples) const
 {
-    ASSUME(count > 0);
-
     const Real coeff{mCoeff};
     Real z1{0.0f};
     auto proc_sample = [coeff,&z1](const Real in) noexcept -> Real
@@ -109,7 +105,7 @@ void BandSplitterR<Real>::applyAllpass(Real *samples, const size_t count) const
         z1 = in - out*coeff;
         return out;
     };
-    std::transform(samples, samples+count, samples, proc_sample);
+    std::transform(samples.begin(), samples.end(), samples.begin(), proc_sample);
 }
 
 
diff --git a/alc/filters/splitter.h b/alc/filters/splitter.h
index 5117a244..d88ef182 100644
--- a/alc/filters/splitter.h
+++ b/alc/filters/splitter.h
@@ -3,6 +3,8 @@
 
 #include <cstddef>
 
+#include "alspan.h"
+
 
 /* Band splitter. Splits a signal into two phase-matching frequency bands. */
 template<typename Real>
@@ -19,15 +21,15 @@ public:
 
     void init(Real f0norm);
     void clear() noexcept { mLpZ1 = mLpZ2 = mApZ1 = 0.0f; }
-    void process(Real *hpout, Real *lpout, const Real *input, const size_t count);
+    void process(const al::span<const Real> input, Real *hpout, Real *lpout);
 
-    void applyHfScale(Real *samples, const Real hfscale, const size_t count);
+    void applyHfScale(const al::span<Real> samples, const Real hfscale);
 
     /* 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 size_t count) const;
+    void applyAllpass(const al::span<Real> samples) const;
 };
 using BandSplitter = BandSplitterR<float>;