gen_padsynth
Files: ftbl.h, ftbl.c
An implementation of the Padsynth Algorithm by Paul Nasca.
This is a basic implemenation of the padsynth algorithm. More information can be found here:
http://zynaddsubfx.sourceforge.net/doc/PADsynth/PADsynth.htm
This gen routine requires libfftw, and is not compiled by default. See config.mk for more info.
sp_gen_padsynth(sp_data *sp, sp_ftbl *ft , sp_ftbl *amps, SPFLOAT f, SPFLOAT bw)
Parameters
amps: ftable of amplitudes to use
(Recommended value: N/A)
f: Base frequency.
(Recommended value: 440.0)
bw: Bandwidth.
(Recommended value: 40.0)
Example Code
#include "soundpipe.h"
typedef struct user_data {
sp_ftbl *ft, *amps;
sp_osc *osc;
SPFLOAT fc;
} user_data;
void process(sp_data *sp, void *userdata) {
user_data *ud = userdata;
//sp->out = ud->ft->tbl[sp->pos % ud->ft->size];
sp_osc_compute(sp, ud->osc, NULL, &sp->out[0]);
}
int main() {
user_data ud;
int i;
sp_data *sp;
sp_create(&sp); sp_ftbl_create(sp, &ud.amps, 64);
sp_ftbl_create(sp, &ud.ft, 262144);
sp_osc_create(&ud.osc);
sp->sr = 96000;
sp->len = ud.ft->size;
ud.amps->tbl[0] = 0.0;
for(i = 1; i < ud.amps->size; i++){
ud.amps->tbl[i] = 1.0 / i;
if((i % 2) == 0) ud.amps->tbl[i] *= 2.0;
}
/* Discovered empirically. multiply frequency by this constant. */
ud.fc = 1 / (6.0 * 440);
sp_gen_padsynth(sp, ud.ft, ud.amps, 440, 40.0);
sp_osc_init(sp, ud.osc, ud.ft, 0);
ud.osc->freq = sp_midi2cps(70) * ud.fc;
ud.osc->amp = 1.0;
sp_process(sp, &ud, process);
sp_osc_destroy(&ud.osc);
sp_ftbl_destroy(&ud.amps);
sp_ftbl_destroy(&ud.ft);
sp_destroy(&sp);
return 0;
}