Use the gaussian filter table for the chorus effect

kcat · Feb 14, 2024 · 5c5da9e · 5c5da9e
1 parent 9c6516e
commit 5c5da9e
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Showing 2 changed files with 18 additions and 21 deletions.
diff --git a/alc/effects/chorus.cpp b/alc/effects/chorus.cpp
@@ -22,27 +22,30 @@
 
 #include <algorithm>
 #include <array>
-#include <climits>
+#include <cmath>
 #include <cstdlib>
-#include <iterator>
+#include <limits>
+#include <variant>
 #include <vector>
 
 #include "alc/effects/base.h"
-#include "almalloc.h"
 #include "alnumbers.h"
 #include "alnumeric.h"
 #include "alspan.h"
+#include "core/ambidefs.h"
 #include "core/bufferline.h"
 #include "core/context.h"
-#include "core/devformat.h"
+#include "core/cubic_tables.h"
 #include "core/device.h"
+#include "core/effects/base.h"
 #include "core/effectslot.h"
 #include "core/mixer.h"
 #include "core/mixer/defs.h"
 #include "core/resampler_limits.h"
 #include "intrusive_ptr.h"
 #include "opthelpers.h"
 
+struct BufferStorage;
 
 namespace {
 
@@ -300,16 +303,20 @@ void ChorusState::process(const size_t samplesToDo, const al::span<const FloatBu
         delaybuf[offset&bufmask] = samplesIn[0][i];
 
         // Tap for the left output.
-        uint delay{offset - (ldelays[i]>>MixerFracBits)};
-        float mu{static_cast<float>(ldelays[i]&MixerFracMask) * (1.0f/MixerFracOne)};
-        lbuffer[i] = cubic(delaybuf[(delay+1) & bufmask], delaybuf[(delay  ) & bufmask],
-            delaybuf[(delay-1) & bufmask], delaybuf[(delay-2) & bufmask], mu);
+        size_t delay{offset - (ldelays[i]>>MixerFracBits)};
+        size_t phase{(ldelays[i]>>(MixerFracBits-gCubicTable.sTableBits))&gCubicTable.sTableMask};
+        lbuffer[i] = delaybuf[(delay+1) & bufmask]*gCubicTable.getCoeff0(phase) +
+            delaybuf[(delay  ) & bufmask]*gCubicTable.getCoeff1(phase) +
+            delaybuf[(delay-1) & bufmask]*gCubicTable.getCoeff2(phase) +
+            delaybuf[(delay-2) & bufmask]*gCubicTable.getCoeff3(phase);
 
         // Tap for the right output.
         delay = offset - (rdelays[i]>>MixerFracBits);
-        mu = static_cast<float>(rdelays[i]&MixerFracMask) * (1.0f/MixerFracOne);
-        rbuffer[i] = cubic(delaybuf[(delay+1) & bufmask], delaybuf[(delay  ) & bufmask],
-            delaybuf[(delay-1) & bufmask], delaybuf[(delay-2) & bufmask], mu);
+        phase = (rdelays[i]>>(MixerFracBits-gCubicTable.sTableBits))&gCubicTable.sTableMask;
+        rbuffer[i] = delaybuf[(delay+1) & bufmask]*gCubicTable.getCoeff0(phase) +
+            delaybuf[(delay  ) & bufmask]*gCubicTable.getCoeff1(phase) +
+            delaybuf[(delay-1) & bufmask]*gCubicTable.getCoeff2(phase) +
+            delaybuf[(delay-2) & bufmask]*gCubicTable.getCoeff3(phase);
 
         // Accumulate feedback from the average delay of the taps.
         delaybuf[offset&bufmask] += delaybuf[(offset-avgdelay) & bufmask] * feedback;

diff --git a/common/alnumeric.h b/common/alnumeric.h
@@ -41,16 +41,6 @@ constexpr auto GetCounterSuffix(size_t count) noexcept -> const char*
 
 constexpr inline float lerpf(float val1, float val2, float mu) noexcept
 { return val1 + (val2-val1)*mu; }
-constexpr inline float cubic(float val1, float val2, float val3, float val4, float mu) noexcept
-{
-    const float mu2{mu*mu}, mu3{mu2*mu};
-    const float a0{-0.5f*mu3 +       mu2 + -0.5f*mu};
-    const float a1{ 1.5f*mu3 + -2.5f*mu2            + 1.0f};
-    const float a2{-1.5f*mu3 +  2.0f*mu2 +  0.5f*mu};
-    const float a3{ 0.5f*mu3 + -0.5f*mu2};
-    return val1*a0 + val2*a1 + val3*a2 + val4*a3;
-}
-
 constexpr inline double lerpd(double val1, double val2, double mu) noexcept
 { return val1 + (val2-val1)*mu; }