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/* VOSIM.C: VOice SIMulation implementation
Copyright 2008 rasmus ekman
rasmus ekman March 13, 2008, for Csound.
This file is part of Csound.
The Csound Library is free software; you can redistribute it
and/or modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
Csound is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with Csound; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
02110-1301 USA
*/
/* Programmer note:
* Pre- and post-conditions are noted at function level.
* These are essential for the code to work at all.
* There are some complications because we accept weird user input:
* (a) kfund < 0: This is forced to positive - no point in "backward" events.
* (b) kform == 0: This leads to infinite length pulse, ie silence.
* (c) kform < 0: Table is read backward.
* If table is symmetric, kform and -kform should give bit-identical outputs.
*
* Don't fiddle with the code unless you understand how the table read
* params pulsephs and pulseinc are used both to read table and to indicate that
* a new pulse should start, and that pulseinc can be negative.
*/
//#include "csdl.h"
#include "csoundCore.h"
#include "interlocks.h"
#include <math.h>
#include <limits.h>
typedef struct {
OPDS h;
MYFLT *ar, *amp, *kfund, *kform, *kdamp, *knofpulse, *kpulsemul,
*iftab, *iskip;
FUNC *ftable;
int32 timrem; /* samples left of event */
int32 pulstogo; /* count of pulses to produce in burst */
int32 pulsephs; /* index into table of this pulse (= MAXLEN / kform) */
int32 pulseinc; /* increment in table of pulse */
MYFLT pulseamp; /* amp of current pulse */
MYFLT ampdecay; /* subtract from amp on new pulse */
MYFLT lenfact; /* increase length of next pulse */
} VOSIM;
/* Post: unless skipping init, timrem == 0 */
int32_t vosimset(CSOUND* csound, VOSIM *p)
{
if (*p->iskip)
return OK;
p->ftable = csound->FTFind(csound, p->iftab);
if (UNLIKELY(p->ftable == NULL)) {
return csound->InitError(csound, Str("vosim: pulse table not found"));
}
p->timrem = p->pulstogo = p->pulsephs = p->pulseinc = 0;
p->pulseamp = p->ampdecay = p->lenfact = FL(0.0);
return OK;
}
/* Pre: timrem == 0.
* Post:
* IF kform >= 0, pulsephs >= FMAXLEN.
* ELSE pulsephs < 0.
* timrem > 0.
*/
void vosim_event(CSOUND* csound, VOSIM *p)
{
MYFLT fundabs = FABS(*p->kfund);
/* count of pulses, (+1 since decr at start of pulse) */
p->pulstogo = 1+(int32)*p->knofpulse;
if (UNLIKELY(fundabs == FL(0.0))) { /* infinitely long event */
p->timrem = INT_MAX;
csound->Warning(csound,
Str("vosim: zero kfund. 'Infinite' length event generated."));
}
else {
p->timrem = (int32)(CS_ESR / fundabs);
if (UNLIKELY(p->timrem == 0)) {
p->timrem = CS_KSMPS;
p->pulstogo = 0;
csound->Warning(csound,
Str("vosim: kfund (%f) > sr. Generating ksmps silence."),
*p->kfund);
}
}
p->pulseinc = (int32)(*p->kform * csound->sicvt);
p->pulsephs = (p->pulseinc >= 0)? MAXLEN : -1; /* starts a new pulse */
p->ampdecay = *p->kdamp;
/* increase initial amp, since it's reduced at pulse start */
p->pulseamp = *p->amp + p->ampdecay;
/* if negative, table is read alternately back-/forward */
p->lenfact = *p->kpulsemul;
/* reduce table rate, since it's increased at pulse start */
if (p->lenfact != FL(0.0))
p->pulseinc /= p->lenfact;
}
/* Pre: pulsephs >= FMAXLEN OR pulsephs < 0.
* Post:
* pulstogo is decremented or zero.
* 0 <= pulsephs < FMAXLEN.
*/
void vosim_pulse(CSOUND* csound, VOSIM *p)
{
IGN(csound);
int32 pulselen;
p->pulsephs &= PHMASK;
p->pulseinc *= p->lenfact;
/* If pulse can't fit in remaining event time, skip and generate silence */
pulselen = (p->pulseinc != FL(0.0))?
(int32)FABS(FMAXLEN / p->pulseinc) : INT_MAX;
if (p->pulstogo-- <= 0 || pulselen > p->timrem) {
p->pulstogo = 0;
}
p->pulseamp -= p->ampdecay;
}
int32_t vosim(CSOUND* csound, VOSIM *p)
{
uint32_t offset = p->h.insdshead->ksmps_offset;
uint32_t early = p->h.insdshead->ksmps_no_end;
uint32_t n, nsmps = CS_KSMPS;
MYFLT *ar = p->ar;
MYFLT *ftdata;
int32 lobits;
FUNC *ftp = p->ftable;
if (UNLIKELY(ftp == NULL)) goto err1;
ftdata = ftp->ftable;
lobits = ftp->lobits;
if (UNLIKELY(offset)) memset(ar, '\0', offset*sizeof(MYFLT));
if (UNLIKELY(early)) {
nsmps -= early;
memset(&ar[nsmps], '\0', early*sizeof(MYFLT));
}
for (n=offset; n<nsmps; n++) {
/* new event? */
if (p->timrem == 0)
vosim_event(csound, p);
/* new pulse? */
if (p->pulsephs >= MAXLEN || p->pulsephs < 0)
vosim_pulse(csound, p);
if (p->pulstogo > 0) {
/* produce one sample */
p->pulsephs &= PHMASK;
ar[n] = *(ftdata + (p->pulsephs >> lobits)) * p->pulseamp;
--p->timrem;
p->pulsephs += p->pulseinc;
}
else {
/* silence after last pulse in burst: */
/* bypass regular synthesis and fill output with zeros */
while (p->timrem && n<nsmps) {
ar[n] = FL(0.0);
--p->timrem;
n++;
}
n--;
}
}
return OK;
err1:
return csound->PerfError(csound, &(p->h),
Str("vosim: not initialised"));
}
/* ar vosim kamp, kFund, kForm, kDamp, kPulseCount, kPulseFactor,
ifn [, iskip] */
#define S(x) sizeof(x)
static OENTRY vosim_localops[] = {
{ "vosim", S(VOSIM), TR, 3, "a", "kkkkkkio", (SUBR)vosimset, (SUBR)vosim }
};
LINKAGE_BUILTIN(vosim_localops)
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