make sound

1 files changed, 93 insertions, 17 deletions

diff --git a/src/mossrose.c b/src/mossrose.c
index fdaa10c..02f063a 100644
--- a/src/mossrose.c
+++ b/src/mossrose.c
@@ -1,17 +1,67 @@
 #include <stdio.h>
+#include <stdlib.h>
 #include <portaudio.h>
 #include "mossrose.h"
+#include "mossrose-mutex.h"
+#include "mossrose-channel.h"
 
 
-PaStream *stream;
-
+/* ~~~~~~~~~~~~~~~~ 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,
@@ -19,39 +69,49 @@ static int callback(
 	const PaStreamCallbackTimeInfo *time_info,
 	void *userdata)
 {
-	static float left = 0;
-	static float right = 0;
-
 	struct audio_output_t *out = output;
+	struct audio_output_t sample;
+
 	for (int i=0; i<frame_count; i++) {
-		out[i].l = left;
-		out[i].r = right;
-		left += 0.01;
-		right += 0.03;
-		if (left > 1) left -= 2;
-		if (right > 1) right -= 2;
+		sample = build_sample();
+		out[i].l = sample.l;
+		out[i].r = sample.r;
 	}
 	return 0;
 }
 
 
-int mr_init(double sample_rate, int n_channels)
+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;
 	}
 
-	err = Pa_OpenDefaultStream(&stream, 0, 2, paFloat32, sample_rate, 0, callback, NULL);
+	/* 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;
 	}
 
-	err = Pa_StartStream(stream);
+	/* start stream */
+	err = Pa_StartStream(mossrose_global.stream);
 	if (err != paNoError) {
 		fprintf(stderr, "failed to start audio stream!\n");
 		return 1;
@@ -61,10 +121,26 @@ int mr_init(double sample_rate, int n_channels)
 };
 
 
-int mr_terminate(double sample_rate, int n_channels)
+int mossrose_play(float *left, float *right, size_t len, int channel)
+{
+	if (channel > 0) {
+		return mossrose_channel_set(mossrose_global.channels+channel, left, right, len, 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 0;
+		}
+		return 1;
+	}
+}
+
+
+int mossrose_terminate(double sample_rate, int n_channels)
 {
-	Pa_AbortStream(stream);
-	Pa_CloseStream(stream);
+	Pa_AbortStream(mossrose_global.stream);
+	Pa_CloseStream(mossrose_global.stream);
 	Pa_Terminate();
 	return 0;
 }