From c423b6c8b77354bee82f14c3b22c5d453d257c19 Mon Sep 17 00:00:00 2001
From: Chris Robinson <chris.kcat@gmail.com>
Date: Sun, 7 Jan 2018 05:58:52 -0800
Subject: [PATCH] Remove the sinc4 table

---
 Alc/ALu.c               |  5 -----
 OpenAL32/Include/alu.h  |  5 -----
 native-tools/bsincgen.c | 47 ++++-------------------------------------
 3 files changed, 4 insertions(+), 53 deletions(-)

diff --git a/Alc/ALu.c b/Alc/ALu.c
index 1964e6c7..97066737 100644
--- a/Alc/ALu.c
+++ b/Alc/ALu.c
@@ -1046,9 +1046,6 @@ static void CalcNonAttnSourceParams(ALvoice *voice, const struct ALvoiceProps *p
         BsincPrepare(voice->Step, &voice->ResampleState.bsinc, &bsinc24);
     else if(props->Resampler == BSinc12Resampler)
         BsincPrepare(voice->Step, &voice->ResampleState.bsinc, &bsinc12);
-    else
-
-        voice->ResampleState.sinc4.filter = sinc4Tab;
     voice->Resampler = SelectResampler(props->Resampler);
 
     /* Calculate gains */
@@ -1396,8 +1393,6 @@ static void CalcAttnSourceParams(ALvoice *voice, const struct ALvoiceProps *prop
         BsincPrepare(voice->Step, &voice->ResampleState.bsinc, &bsinc24);
     else if(props->Resampler == BSinc12Resampler)
         BsincPrepare(voice->Step, &voice->ResampleState.bsinc, &bsinc12);
-    else
-        voice->ResampleState.sinc4.filter = sinc4Tab;
     voice->Resampler = SelectResampler(props->Resampler);
 
     if(Distance > FLT_EPSILON)
diff --git a/OpenAL32/Include/alu.h b/OpenAL32/Include/alu.h
index c427df0c..2c326327 100644
--- a/OpenAL32/Include/alu.h
+++ b/OpenAL32/Include/alu.h
@@ -84,13 +84,8 @@ typedef struct BsincState {
     const ALfloat *filter;
 } BsincState;
 
-typedef struct Sinc4State {
-    const ALfloat (*filter)[4];
-} Sinc4State;
-
 typedef union InterpState {
     BsincState bsinc;
-    Sinc4State sinc4;
 } InterpState;
 
 typedef const ALfloat* (*ResamplerFunc)(const InterpState *state,
diff --git a/native-tools/bsincgen.c b/native-tools/bsincgen.c
index 2a7e4326..49102279 100644
--- a/native-tools/bsincgen.c
+++ b/native-tools/bsincgen.c
@@ -50,6 +50,10 @@
 #define log2(x)  (log(x) / log(2.0))
 #endif
 
+/* Same as in alu.h! */
+#define FRACTIONBITS (12)
+#define FRACTIONONE  (1<<FRACTIONBITS)
+
 // The number of distinct scale and phase intervals within the filter table.
 // Must be the same as in alu.h!
 #define BSINC_SCALE_COUNT (16)
@@ -316,48 +320,6 @@ static void BsiGenerateTables(FILE *output, const char *tabname, const double re
 }
 
 
-/* These methods generate a much simplified 4-point sinc interpolator using a
- * Kaiser window. This is much simpler to process at run-time, but has notably
- * more aliasing noise.
- */
-
-/* Same as in alu.h! */
-#define FRACTIONBITS (12)
-#define FRACTIONONE  (1<<FRACTIONBITS)
-
-static void Sinc4GenerateTables(FILE *output, const double rejection)
-{
-    static double filter[FRACTIONONE][4];
-
-    const double width = CalcKaiserWidth(rejection, 3);
-    const double beta = CalcKaiserBeta(rejection);
-    const double scaleBase = width / 2.0;
-    const double scaleRange = 1.0 - scaleBase;
-    const double scale = scaleBase + scaleRange;
-    const double a = MinDouble(4.0, floor(4.0 / (2.0*scale)));
-    const int m = 2 * (int)a;
-    const int l = (m/2) - 1;
-    int pi;
-    for(pi = 0;pi < FRACTIONONE;pi++)
-    {
-        const double phase = l + ((double)pi / FRACTIONONE);
-        int i;
-
-        for(i = 0;i < m;i++)
-        {
-            double x = i - phase;
-            filter[pi][i] = Kaiser(beta, x / a) * Sinc(x);
-        }
-    }
-
-    fprintf(output, "alignas(16) static const float sinc4Tab[FRACTIONONE][4] = {\n");
-    for(pi = 0;pi < FRACTIONONE;pi++)
-        fprintf(output, "    { %+14.9ef, %+14.9ef, %+14.9ef, %+14.9ef },\n",
-                filter[pi][0], filter[pi][1], filter[pi][2], filter[pi][3]);
-    fprintf(output, "};\n\n");
-}
-
-
 int main(int argc, char *argv[])
 {
     FILE *output;
@@ -396,7 +358,6 @@ int main(int argc, char *argv[])
     BsiGenerateTables(output, "bsinc24", 60.0, 23);
     /* An 11th order filter with a -60dB drop at nyquist. */
     BsiGenerateTables(output, "bsinc12", 60.0, 11);
-    Sinc4GenerateTables(output, 60.0);
 
     if(output != stdout)
         fclose(output);