prosperon/source/engine/dsp.c

233 lines
4.7 KiB
C

#include "dsp.h"
#include "sound.h"
#include "limits.h"
#include "math.h"
#include "stdlib.h"
#define PI 3.14159265
struct dsp_filter make_dsp(void *data, void (*in)(void *data, short *out, int n)) {
struct dsp_filter new;
new.data = data;
new.filter = in;
}
void dsp_run(struct dsp_filter filter, short *out, int n) {
filter.filter(filter.data, out, n);
}
void am_mod(struct dsp_ammod *mod, short *c, int n)
{
dsp_run(mod->ina, mod->abuf, n);
dsp_run(mod->inb, mod->bbuf, n);
for (int i = 0; i < n*2; i++) {
c[i] = (mod->abuf[i]*mod->bbuf[i])>>15;
//c[i] = mod->abuf[i];
}
}
static struct wav make_wav(float freq, int sr, int ch) {
struct wav new;
new.ch = ch;
new.samplerate = sr;
new.frames = sr/freq;
new.data = calloc(new.frames*new.ch, sizeof(short));
return new;
}
struct wav gen_sine(float amp, float freq, int sr, int ch)
{
struct wav new = make_wav(freq, sr, ch);
if (amp > 1) amp = 1;
if (amp < 0) amp = 0;
short samp = amp*SHRT_MAX;
short *data = (short*)new.data;
for (int i = 0; i < new.frames; i++) {
short val = samp * sin(2*PI*((float)i / new.frames));
for (int j = 0; j < new.ch; j++) {
data[i*new.ch+j] = val;
}
}
printf("Made sine with %i frames.\n", new.frames);
return new;
}
struct wav gen_square(float amp, float freq, int sr, int ch)
{
struct wav new = make_wav(freq, sr, ch);
int crossover = new.frames/2;
if (amp > 1) amp = 1;
if (amp < 0) amp = 0;
short samp = amp * SHRT_MAX;
short *data = (short*)new.data;
for (int i = 0; i < new.frames; i++) {
short val = -2 * floor(2 * i / new.frames) + 1;
for (int j = 0; j < new.ch; j++) {
data[i*new.frames+j] = val;
}
}
return new;
}
struct wav gen_triangle(float amp, float freq, int sr, int ch)
{
struct wav new = make_wav(freq, sr, ch);
if (amp > 1) amp = 1;
if (amp < 0) amp = 0;
short *data = (short*)new.data;
for (int i = 0; i < new.frames; i++) {
short val = 2 * abs( (i/new.frames) - floor( (i/new.frames) + 0.5));
for (int j = 0; j < new.ch; j++) {
data[i+j] = val;
}
}
}
struct wav gen_saw(float amp, float freq, int sr, int ch)
{
struct wav new = make_wav(freq, sr, ch);
if (amp > 1) amp = 1;
if (amp < 0) amp = 0;
short samp = amp*SHRT_MAX;
short *data = (short*)new.data;
for (int i = 0; i < new.frames; i++) {
short val = samp * 2 * i/sr - samp;
for (int j = 0; j < new.ch; j++) {
data[i+j] = val;
}
}
}
void make_dsp_filter()
{
}
void dsp_filter(short *in, short *out, int samples, struct dsp_delay *d)
{
}
void dsp_rectify(short *in, short *out, int n)
{
for (int i = 0; i < n; i++) {
out[i] = abs(in[i]);
}
}
struct phasor phasor_make(unsigned int sr, float freq)
{
struct phasor new;
new.sr = sr;
new.cur = 0.f;
new.freq = freq;
new.cstep = 0;
new.clen = new.sr / new.freq;
new.cache = malloc(new.clen * sizeof(float));
for (int i = 0; i < new.clen; i++) {
new.cache[i] = (float)i / new.clen;
}
return new;
}
float phasor_step(struct phasor *p)
{
p->cur += p->freq/p->sr;
if (p->cur >= 1.f) p->cur = 0.f;
return p->cur;
/*
float ret = p->cache[p->cstep++];
if (p->cstep ==p->clen) p->cstep = 0;
return ret;
*/
}
float sin_phasor(float p)
{
return sin(2*PI*p);
}
float square_phasor(float p)
{
return lround(p);
}
float saw_phasor(float p)
{
return 2*p-1;
}
float tri_phasor(float p)
{
return 4*(p * 0.5f ? p : (1-p)) - 1;
}
void osc_fillbuf(struct osc *osc, short *buf, int n)
{
for (int i = 0; i < n; i++) {
short val = SHRT_MAX * osc->f(phasor_step(&osc->p));
buf[i*2] = buf[i*2+1] = val;
}
}
void gen_whitenoise(void *data, short *buf, int n)
{
for (int i = 0; i < n; i++) {
for (int j = 0; j < 2; j++) {
buf[i*2+j] = (rand()>>15) - USHRT_MAX;
}
}
}
struct dsp_delay dsp_delay_make(unsigned int ms_delay)
{
struct dsp_delay new;
new.ms_delay = ms_delay;
/* Circular buffer size is enough to have the delay */
unsigned int datasize = ms_delay * CHANNELS * (SAMPLERATE / 1000);
new.buf = circbuf_init(sizeof(short), datasize);
new.buf.write = datasize;
printf("Buffer size is %u.\n", new.buf.len);
return new;
}
void dsp_delay_filbuf(struct dsp_delay *delay, short *buf, int n)
{
static short cache[BUF_FRAMES*2];
dsp_run(delay->in, cache, n);
for (int i = 0; i < n*2; i++) {
cbuf_push(&delay->buf, cache[i] / 2);
buf[i] = cache[i] + cbuf_shift(&delay->buf);
}
}