ref: 70285956de156f146984f42c8ffa42401d42edd7
dir: /tangled/bigverb.c/
#line 93 "bigverb.org"
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#define SK_BIGVERB_PRIV
#include "bigverb.h"
#line 56 "bigverb.org"
struct bigverb_paramset {
int delay; /* in samples, 44.1 kHz */
int drift; /* 1/10 milliseconds */
int randfreq; /* Hertz * 1000 */
int seed;
};
static const struct bigverb_paramset params[8] = {
{0x09a9, 0x0a, 0xc1c, 0x07ae},
{0x0acf, 0x0b, 0xdac, 0x7333},
{0x0c91, 0x11, 0x456, 0x5999},
{0x0de5, 0x06, 0xf85, 0x2666},
{0x0f43, 0x0a, 0x925, 0x50a3},
{0x101f, 0x0b, 0x769, 0x5999},
{0x085f, 0x11, 0x37b, 0x7333},
{0x078d, 0x06, 0xc95, 0x3851}
};
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#define FRACSCALE 0x10000000
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#define FRACMASK 0xFFFFFFF
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#define FRACNBITS 28
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static int get_delay_size(const struct bigverb_paramset *p, int sr);
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static void delay_init(sk_bigverb_delay *d,
const struct bigverb_paramset *p,
SKFLT *buf,
size_t sz,
int sr);
#line 619 "bigverb.org"
static SKFLT delay_compute(sk_bigverb_delay *d,
SKFLT in,
SKFLT fdbk,
SKFLT filt,
int sr);
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static void generate_next_line(sk_bigverb_delay *d, int sr);
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sk_bigverb * sk_bigverb_new(int sr)
{
sk_bigverb *bv;
bv = calloc(1, sizeof(sk_bigverb));
bv->sr = sr;
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sk_bigverb_size(bv, 0.93);
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sk_bigverb_cutoff(bv, 10000.0);
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bv->pcutoff = -1;
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bv->filt = 1.0;
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bv->buf = NULL;
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{
unsigned long total_size;
int i;
SKFLT *buf;
total_size = 0;
buf = NULL;
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for (i = 0; i < 8; i++) {
total_size += get_delay_size(¶ms[i], sr);
}
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buf = calloc(1, sizeof(SKFLT) * total_size);
bv->buf = buf;
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{
unsigned long bufpos;
bufpos = 0;
for (i = 0; i < 8; i++) {
unsigned int sz;
sz = get_delay_size(¶ms[i], sr);
delay_init(&bv->delay[i], ¶ms[i],
&buf[bufpos], sz, sr);
bufpos += sz;
}
}
#line 417 "bigverb.org"
}
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return bv;
}
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void sk_bigverb_del(sk_bigverb *bv)
{
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free(bv->buf);
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free(bv);
bv = NULL;
}
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void sk_bigverb_size(sk_bigverb *bv, SKFLT size)
{
bv->size = size;
}
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void sk_bigverb_cutoff(sk_bigverb *bv, SKFLT cutoff)
{
bv->cutoff = cutoff;
}
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void sk_bigverb_tick(sk_bigverb *bv,
SKFLT inL, SKFLT inR,
SKFLT *outL, SKFLT *outR)
{
/* TODO: implement */
SKFLT lsum, rsum;
lsum = 0;
rsum = 0;
#line 329 "bigverb.org"
if (bv->pcutoff != bv->cutoff) {
bv->pcutoff = bv->cutoff;
bv->filt = 2.0 - cos(bv->pcutoff * 2 * M_PI / bv->sr);
bv->filt = bv->filt - sqrt(bv->filt * bv->filt - 1.0);
}
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{
int i;
SKFLT jp;
jp = 0;
for (i = 0; i < 8; i++) {
jp += bv->delay[i].y;
}
jp *= 0.25;
inL = jp + inL;
inR = jp + inR;
}
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{
int i;
for (i = 0; i < 8; i++) {
if (i & 1) {
rsum += delay_compute(&bv->delay[i],
inR,
bv->size,
bv->filt,
bv->sr);
} else {
lsum += delay_compute(&bv->delay[i],
inL,
bv->size,
bv->filt,
bv->sr);
}
}
}
rsum *= 0.35f;
lsum *= 0.35f;
#line 309 "bigverb.org"
*outL = lsum;
*outR = rsum;
}
#line 439 "bigverb.org"
static int get_delay_size(const struct bigverb_paramset *p, int sr)
{
SKFLT sz;
sz = (SKFLT)p->delay/44100 + (p->drift * 0.0001) * 1.125;
return floor(16 + sz*sr);
}
#line 520 "bigverb.org"
static void delay_init(sk_bigverb_delay *d,
const struct bigverb_paramset *p,
SKFLT *buf,
size_t sz,
int sr)
{
SKFLT readpos;
#line 541 "bigverb.org"
d->buf = buf;
d->sz = sz;
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d->wpos = 0;
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d->rng = p->seed;
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readpos = ((SKFLT)p->delay / 44100);
readpos += d->rng * (p->drift * 0.0001) / 32768.0;
readpos = sz - (readpos * sr);
d->irpos = floor(readpos);
d->frpos = floor((readpos - d->irpos) * FRACSCALE);
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d->inc = 0;
d->counter = 0;
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d->maxcount = round((sr / ((SKFLT)p->randfreq * 0.001)));
#line 973 "bigverb.org"
d->dels = p->delay / 44100.0;
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d->drift = p->drift;
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generate_next_line(d, sr);
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d->y = 0.0;
#line 528 "bigverb.org"
}
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static SKFLT delay_compute(sk_bigverb_delay *del,
SKFLT in,
SKFLT fdbk,
SKFLT filt,
int sr)
{
SKFLT out;
SKFLT frac_norm;
SKFLT a, b, c, d;
SKFLT s[4];
out = 0;
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del->buf[del->wpos] = in - del->y;
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del->wpos++;
if (del->wpos >= del->sz) del->wpos -= del->sz;
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if (del->frpos >= FRACSCALE) {
del->irpos += del->frpos >> FRACNBITS;
del->frpos &= FRACMASK;
}
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if (del->irpos >= del->sz) del->irpos -= del->sz;
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frac_norm = del->frpos / (SKFLT)FRACSCALE;
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{
SKFLT tmp[2];
d = ((frac_norm * frac_norm) - 1) / 6.0;
tmp[0] = ((frac_norm + 1.0) * 0.5);
tmp[1] = 3.0 * d;
a = tmp[0] - 1.0 - d;
c = tmp[0] - tmp[1];
b = tmp[1] - frac_norm;
}
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{
int n;
SKFLT *x;
n = del->irpos;
x = del->buf;
if (n > 0 && n < (del->sz - 2)) {
s[0] = x[n - 1];
s[1] = x[n];
s[2] = x[n + 1];
s[3] = x[n + 2];
} else {
int k;
n--;
if (n < 0) n += del->sz;
s[0] = x[n];
for (k = 0; k < 3; k++) {
n++;
if (n >= del->sz) n -= del->sz;
s[k + 1] = x[n];
}
}
}
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out = (a*s[0] + b*s[1] + c*s[2] + d*s[3]) * frac_norm + s[1];
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del->frpos += del->inc;
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out *= fdbk;
out += (del->y - out) * filt;
del->y = out;
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del->counter--;
if (del->counter <= 0) {
generate_next_line(del, sr);
}
#line 650 "bigverb.org"
return out;
}
#line 1008 "bigverb.org"
static void generate_next_line(sk_bigverb_delay *d, int sr)
{
SKFLT curdel;
SKFLT nxtdel;
SKFLT inc;
#line 915 "bigverb.org"
if (d->rng < 0) d->rng += 0x10000;
/* 5^6 = 15625 */
d->rng = (1 + d->rng * 0x3d09);
d->rng &= 0xFFFF;
if (d->rng >= 0x8000) d->rng -= 0x10000;
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d->counter = d->maxcount;
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curdel = d->wpos -
(d->irpos + (d->frpos/(SKFLT)FRACSCALE));
while (curdel < 0) curdel += d->sz;
curdel /= sr;
#line 961 "bigverb.org"
nxtdel = (d->rng * (d->drift * 0.0001) / 32768.0) + d->dels;
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inc = ((curdel - nxtdel) / (SKFLT)d->counter)*sr;
inc += 1;
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d->inc = floor(inc * FRACSCALE);
#line 1018 "bigverb.org"
}
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