ref: f786bba6a02a7ec34901b55858159020385def4d
parent: 88b6638a2639331ca054357ae9f645a04a5d9983
author: Olav Sørensen <olav.sorensen@live.no>
date: Mon Apr 22 09:22:27 EDT 2024
Small code cleanup
--- a/src/mixer/ft2_cubic_spline.c
+++ b/src/mixer/ft2_cubic_spline.c
@@ -18,7 +18,7 @@
float *fPtr = fCubicSplineLUT;
for (int32_t i = 0; i < CUBIC_SPLINE_PHASES; i++)
{- const double x1 = i * (1.0 / (double)CUBIC_SPLINE_PHASES); // i / CUBIC_SPLINE_PHASES
+ const double x1 = i * (1.0 / CUBIC_SPLINE_PHASES);
const double x2 = x1 * x1; // x^2
const double x3 = x2 * x1; // x^3
--- a/src/mixer/ft2_cubic_spline.h
+++ b/src/mixer/ft2_cubic_spline.h
@@ -5,14 +5,14 @@
#include "ft2_mix.h" // MIXER_FRAC_BITS
#define CUBIC_SPLINE_TAPS 4
-#define CUBIC_WIDTH_BITS 2 // log2(CUBIC_SPLINE_TAPS)
+#define CUBIC_SPLINE_WIDTH_BITS 2 // log2(CUBIC_SPLINE_TAPS)
// 8192 is a good compromise
#define CUBIC_SPLINE_PHASES 8192
-#define CUBIC_SPLINE_PHASES_BITS 13 // log2(CUBIC_PHASES)
+#define CUBIC_SPLINE_PHASES_BITS 13 // log2(CUBIC_SPLINE_PHASES)
// do not change these!
-#define CUBIC_SPLINE_FSHIFT (MIXER_FRAC_BITS-(CUBIC_SPLINE_PHASES_BITS+CUBIC_WIDTH_BITS))
+#define CUBIC_SPLINE_FSHIFT (MIXER_FRAC_BITS-(CUBIC_SPLINE_PHASES_BITS+CUBIC_SPLINE_WIDTH_BITS))
#define CUBIC_SPLINE_FMASK ((CUBIC_SPLINE_TAPS*CUBIC_SPLINE_PHASES)-CUBIC_SPLINE_TAPS)
extern float *fCubicSplineLUT;
--- a/src/mixer/ft2_windowed_sinc.c
+++ b/src/mixer/ft2_windowed_sinc.c
@@ -22,15 +22,18 @@
// zeroth-order modified Bessel function of the first kind (series approximation)
static double besselI0(double z)
{+#define EPSILON (1E-15)
+
double s = 1.0, ds = 1.0, d = 2.0;
+ const double zz = z * z;
do
{- ds *= (z * z) / (d * d);
+ ds *= zz / (d * d);
s += ds;
d += 2.0;
}
- while (ds > s*1E-15);
+ while (ds > s*EPSILON);
return s;
}
@@ -39,12 +42,12 @@
{const double I0Beta = besselI0(beta);
const double kPi = MY_PI * cutoff;
+ const double xMul = 1.0 / ((numTaps / 2) * (numTaps / 2));
const uint32_t length = numTaps * SINC_PHASES;
- const uint32_t tapBits = (int32_t)log2(numTaps);
+ const uint32_t tapBits = (uint32_t)log2(numTaps);
const uint32_t tapsMinus1 = numTaps - 1;
- const double xMul = 1.0 / ((numTaps / 2) * (numTaps / 2));
- const int32_t midTap = (numTaps / 2) * SINC_PHASES;
+ const int32_t midPoint = (numTaps / 2) * SINC_PHASES;
for (uint32_t i = 0; i < length; i++)
{@@ -51,9 +54,9 @@
const int32_t ix = ((tapsMinus1 - (i & tapsMinus1)) << SINC_PHASES_BITS) + (i >> tapBits);
double dSinc = 1.0;
- if (ix != midTap)
+ if (ix != midPoint)
{- const double x = (ix - midTap) * (1.0 / SINC_PHASES);
+ const double x = (ix - midPoint) * (1.0 / SINC_PHASES);
const double xPi = x * kPi;
// sinc with Kaiser window
--
⑨