/* This code is placed in the public domain. */ #include <stdlib.h>#include "soundpipe.h" #ifndef max#define max(a, b) ((a > b) ? a : b)#endif #ifndef min#define min(a, b) ((a < b) ? a : b)#endif  int sp_smoothdelay_create(sp_smoothdelay **p){    *p = malloc(sizeof(sp_smoothdelay));    return SP_OK;} int sp_smoothdelay_destroy(sp_smoothdelay **p){    free((*p)->buf1);    free((*p)->buf2);    free(*p);    return SP_OK;} int sp_smoothdelay_init(sp_data *sp, sp_smoothdelay *p,        SPFLOAT maxdel, uint32_t interp){    uint32_t n = (int32_t)(maxdel * sp->sr)+1;    p->sr = sp->sr;    p->del = maxdel * 0.5;    p->pdel = -1;    p->maxdel = maxdel;    p->feedback = 0;    p->maxbuf = n - 1;    p->maxcount = interp;     p->buf1 = calloc(1, n * sizeof(SPFLOAT));    p->bufpos1 = 0;    p->deltime1 = (uint32_t) (p->del * sp->sr);     p->buf2 = calloc(1, n * sizeof(SPFLOAT));    p->bufpos2 = 0;    p->deltime2 = p->deltime1;     p->counter = 0;    p->curbuf = 0;    return SP_OK;} static SPFLOAT delay_sig(SPFLOAT *buf,        uint32_t *bufpos,        uint32_t deltime,        SPFLOAT fdbk,        SPFLOAT in){    SPFLOAT delay = buf[*bufpos];    SPFLOAT sig = (delay * fdbk) + in;    buf[*bufpos] = sig;    *bufpos = (*bufpos + 1) % deltime;    return delay;} int sp_smoothdelay_compute(sp_data *sp, sp_smoothdelay *p, SPFLOAT *in, SPFLOAT *out){    SPFLOAT *buf1;    SPFLOAT *buf2;    SPFLOAT it;    SPFLOAT del1;    SPFLOAT del2;     *out = 0;    if (p->del != p->pdel && p->counter == 0) {        uint32_t dels = min((uint32_t)(p->del * sp->sr), p->maxbuf);         /* initial delay time sets time for both buffers */         if(p->pdel < 0) {            p->deltime1 = dels;            p->deltime2 = dels;        }         p->pdel = p->del;         if(dels == 0) dels = 1;         if(p->curbuf == 0) {            p->curbuf = 1;            p->deltime2 = dels;        } else {            p->curbuf = 0;            p->deltime1 = dels;        }        p->counter = p->maxcount;    }       buf1 = p->buf1;    buf2 = p->buf2;    it = (SPFLOAT)p->counter / p->maxcount;    if (p->counter != 0) p->counter--;     del1 = delay_sig(buf1, &p->bufpos1,            p->deltime1, p->feedback, *in);     del2 = delay_sig(buf2, &p->bufpos2,            p->deltime2, p->feedback, *in);     if (p->curbuf == 0) {        /* 1 to 2 */        *out = (del1 * it) + (del2 * (1 - it));    } else {        /* 2 to 1 */        *out = (del2 * it) + (del1 * (1 - it));    }    return SP_OK;}