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#include <stdio.h>
#include <stdlib.h>
#include <portaudio.h>
#include <mossrose.h>
#include "mutex.h"
#include "channel.h"
/* ~~~~~~~~~~~~~~~~ type definitions ~~~~~~~~~~~~~~~~ */
/* audio output */
struct audio_output_t {
float l;
float r;
};
/* ~~~~~~~~~~~~~~~~ globals ~~~~~~~~~~~~~~~~ */
struct mossrose_globals_t {
PaStream *stream;
struct mossrose_channel_t *channels;
int n_channels;
} mossrose_global;
struct audio_output_t build_sample()
{
struct audio_output_t out;
out.l = 0; out.r = 0;
/* loop variables */
struct mossrose_channel_t *chan;
float chan_l, chan_r;
for (int i=0; i<mossrose_global.n_channels; i++) {
chan = mossrose_global.channels + i;
if (mossrose_mutex_trylock(&(chan->mutex)) != 0) {
/* can't lock the mutex, this channel is being modified */
printf("can't lock channel %d\n", i);
continue;
}
if (chan->n_samples == 0) {
/* channel is not currently in use, skip */
}
else {
if (mossrose_channel_advance(&chan_l, &chan_r, chan) != 0)
/* channel is done playing, reset */
mossrose_channel_reset(chan);
else {
out.l += chan_l;
out.r += chan_r;
}
}
mossrose_mutex_unlock(&(chan->mutex));
}
return out;
}
static int callback(
const void *input,
void *output,
unsigned long frame_count,
const PaStreamCallbackTimeInfo *time_info,
void *userdata)
{
struct audio_output_t *out = output;
struct audio_output_t sample;
for (int i=0; i<frame_count; i++) {
sample = build_sample();
out[i].l = sample.l;
out[i].r = sample.r;
}
return 0;
}
int mossrose_init(double sample_rate, int n_channels)
{
/* initialize channels */
mossrose_global.n_channels = n_channels;
mossrose_global.channels = malloc(n_channels * sizeof(struct mossrose_channel_t));
if (mossrose_global.channels == NULL) {
fprintf(stderr, "failed to allocate memory for %d channels", n_channels);
return 1;
}
for (int i=0; i<n_channels; i++) {
mossrose_channel_init(mossrose_global.channels + i);
}
PaError err;
/* initialize portaudio */
err = Pa_Initialize();
if (err != paNoError) {
fprintf(stderr, "failed to initialize PortAudio!\n");
return 1;
}
/* open stream */
err = Pa_OpenDefaultStream(&(mossrose_global.stream), 0, 2, paFloat32, sample_rate, 0, callback, NULL);
if (err != paNoError) {
fprintf(stderr, "failed to open audio stream!\n");
return 1;
}
/* start stream */
err = Pa_StartStream(mossrose_global.stream);
if (err != paNoError) {
fprintf(stderr, "failed to start audio stream!\n");
return 1;
}
return 0;
};
int mossrose_play(float *left, float *right, size_t len, int channel)
{
if (channel > 0) {
if (mossrose_channel_set(mossrose_global.channels+channel, left, right, len, 1) == 0)
return channel;
else
return -1;
}
else {
struct mossrose_channel_t *chan;
for (int i=0; i<mossrose_global.n_channels; i++) {
chan = mossrose_global.channels + i;
if (mossrose_channel_set(chan, left, right, len, 0) == 0) return i;
}
return -1;
}
}
int mossrose_terminate(double sample_rate, int n_channels)
{
Pa_AbortStream(mossrose_global.stream);
Pa_CloseStream(mossrose_global.stream);
Pa_Terminate();
return 0;
}
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