/* This code is placed in the public domain. */ #include <stdlib.h>#include "soundpipe.h" int sp_tenv_create(sp_tenv **p){    *p = malloc(sizeof(sp_tenv));    return SP_OK;} int sp_tenv_destroy(sp_tenv **p){    free(*p);    return SP_OK;} static void sp_tenv_reinit(void *ud){    sp_tenv *env = ud;    env->pos = 0;    env->atk_end = env->sr * env->atk;    env->rel_start = env->sr * (env->atk + env->hold);    env->atk_slp = 1.0 / env->atk_end;    env->rel_slp = -1.0 / (env->sr * env->rel);    env->totaldur = env->sr * (env->atk + env->hold + env->rel);} static void sp_tenv_comp(void *ud, SPFLOAT *out){    sp_tenv *env = ud;    SPFLOAT sig;    uint32_t pos = env->pos;    *out = 0.0;     if (pos < env->atk_end) {        sig = env->last + env->atk_slp;    } else if (pos < env->rel_start) {        sig = 1.0;    } else if (pos < env->totaldur) {        sig = env->last + env->rel_slp;    } else{        sig = 0.0;    }     sig = (sig > 1.0) ? 1.0 : sig;    sig = (sig < 0.0) ? 0.0 : sig;     /* Internal input signal mode */    if (env->sigmode) {        *out = env->input * sig;    } else {        *out = sig;    }     env->pos++;    env->last = sig;} int sp_tenv_init(sp_data *sp, sp_tenv *p){    p->pos = 0;    p->last = 0;    p->atk = 0.1;    p->hold = 0.3;    p->rel = 0.2;    p->sigmode = 0;    p->input = 0;     p->sr = sp->sr;    p->atk_end = p->sr * p->atk;    p->rel_start = p->sr * (p->atk + p->hold);    p->atk_slp = 1.0 / p->atk_end;    p->rel_slp = -1.0 / (p->sr * p->rel);    p->totaldur = p->sr * (p->atk + p->hold + p->rel);     p->started = 0;    return SP_OK;} int sp_tenv_compute(sp_data *sp, sp_tenv *p, SPFLOAT *in, SPFLOAT *out){    USED(sp);     if (*in) {        sp_tenv_reinit(p);        p->started = 1;    }     if (p->started) sp_tenv_comp(p, out);    else *out = 0;     return SP_OK;}