/* This code is placed in the public domain. */ #include <stdlib.h>#include <math.h>#include "soundpipe.h"#include "lib/dr_wav/sp_dr_wav.h" #define WAVIN_BUFSIZE 1024 struct sp_wavin {    SPFLOAT buf[WAVIN_BUFSIZE];    int count;    drwav *wav;    unsigned long pos;    unsigned long buf_start;    unsigned long buf_end;}; int sp_wavin_create(sp_wavin **p){    *p = malloc(sizeof(sp_wavin));    return SP_OK;} int sp_wavin_destroy(sp_wavin **p){    sp_drwav_uninit((*p)->wav);    free((*p)->wav);    free(*p);    return SP_OK;} int sp_wavin_init(sp_data *sp, sp_wavin *p, const char *filename){    USED(sp);     p->count = 0;    p->pos = 0;    p->buf_start = 0;    p->buf_end = 0;    p->wav = calloc(1, sp_drwav_size());    sp_drwav_init_file(p->wav, filename);    return SP_OK;} static void read_block(sp_data *sp, sp_wavin *p, unsigned long position){    unsigned long samps_read;    sp_wavin_seek(sp, p, position);    samps_read = sp_drwav_read_f32(p->wav, WAVIN_BUFSIZE, p->buf);    p->buf_start = position;    p->buf_end = position + samps_read - 1;} int sp_wavin_compute(sp_data *sp, sp_wavin *p, SPFLOAT *in, SPFLOAT *out){    USED(in);     if (p->pos > sp_drwav_sampcount(p->wav)) {        *out = 0;        return SP_OK;    }     if (p->count == 0) {        read_block(sp, p, p->pos);    }     *out = p->buf[p->count];    p->count = (p->count + 1) % WAVIN_BUFSIZE;    p->pos++;    return SP_OK;} int sp_wavin_get_sample(sp_data *sp, sp_wavin *p, SPFLOAT *out, SPFLOAT pos){    unsigned long ipos;    float samp1, samp2;    float frac;    int buf_pos;     ipos = floor(pos);     if(!(ipos >= p->buf_start && ipos < (p->buf_end - 1))       || (p->buf_start == p->buf_end)) {        read_block(sp, p, ipos);    }     frac = pos - ipos;     buf_pos = (int)(ipos - p->buf_start);    samp1 = p->buf[buf_pos];    samp2 = p->buf[buf_pos + 1];     *out = samp1 + (samp2 - samp1) * frac;    return SP_OK;}  int sp_wavin_reset_to_start(sp_data *sp, sp_wavin *p){    sp_wavin_seek(sp, p, 0);    return SP_OK;} int sp_wavin_seek(sp_data *sp, sp_wavin *p, unsigned long sample){    USED(sp);     sp_drwav_seek_to_sample(p->wav, sample);    return SP_OK;}