# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1348021363 -10800
# Node ID 995191474cc0395fd7bb5cb0b8eaaf9048c1c28f
# Parent  1ea56011c1ff181858f92b68a87dfc96929b7a82
writting the stream audio player

diff -r 1ea56011c1ff -r 995191474cc0 prototype/src/audio/stream.cc
--- a/prototype/src/audio/stream.cc	Wed Sep 19 01:08:41 2012 +0300
+++ b/prototype/src/audio/stream.cc	Wed Sep 19 05:22:43 2012 +0300
@@ -1,13 +1,107 @@
+#include <stdio.h>
 #include "stream.h"
+#include "openal.h"
+
+AudioStream::AudioStream()
+{
+	alsrc = 0;
+	poll_interval = 250;
+	done = true;
+	loop = false;
+}
 
 AudioStream::~AudioStream()
 {
+	stop();
 }
 
-void AudioStream::play()
+void AudioStream::play(bool loop)
 {
+	this->loop = loop;
+	done = false;
+	play_thread = std::thread(&AudioStream::poll_loop, this);
 }
 
 void AudioStream::stop()
 {
+	if(alsrc) {
+		done = true;
+		alSourceStop(alsrc);
+		play_thread.join();
+	}
 }
+
+static ALenum alformat(AudioStreamBuffer *buf)
+{
+	return buf->channels == 1 ? AL_FORMAT_MONO16 : AL_FORMAT_STEREO16;
+}
+
+// thread function
+void AudioStream::poll_loop()
+{
+	static const int num_buffers = 3;
+	AudioStreamBuffer buf;
+	unsigned int albuf[num_buffers];
+
+	alGenSources(1, &alsrc);
+	alGenBuffers(num_buffers, albuf);
+
+	for(int i=0; i<num_buffers; i++) {
+		if(more_samples(&buf)) {
+			alSourceQueueBuffers(alsrc, 1, albuf + i);
+		} else {
+			break;
+		}
+	}
+
+	while(!done) {
+		/* find out how many (if any) of the queued buffers are
+		 * done, and free to be reused.
+		 */
+		int num_buf_done;
+		alGetSourcei(alsrc, AL_BUFFERS_PROCESSED, &num_buf_done);
+		for(int i=0; i<num_buf_done; i++) {
+			// unqueue a buffer...
+			unsigned int buf_id;
+			alSourceUnqueueBuffers(alsrc, 1, &buf_id);
+
+			// if there are more data, fill it up and requeue it
+			if(more_samples(&buf)) {
+				int bufsz = buf.num_samples * buf.channels * 2;	// 2 is for 16bit samples
+				alBufferData(buf_id, alformat(&buf), buf.samples, bufsz, buf.sample_rate);
+				if(alGetError()) {
+					fprintf(stderr, "failed to load sample data into OpenAL buffer\n");
+				}
+			} else {
+				// no more data...
+				if(loop) {
+					rewind();
+				} else {
+					done = true;
+				}
+			}
+		}
+
+		if(num_buf_done) {
+			// make sure playback didn't stop
+			int state;
+			alGetSourcei(alsrc, AL_SOURCE_STATE, &state);
+			if(state != AL_PLAYING) {
+				alSourcePlay(alsrc);
+			}
+		}
+
+		std::chrono::milliseconds dur{poll_interval};
+		std::this_thread::sleep_for(dur);
+	}
+
+	// done with the data, wait for the source to stop playing before cleanup
+	int state;
+	while(alGetSourcei(alsrc, AL_SOURCE_STATE, &state), state == AL_PLAYING) {
+		std::this_thread::yield();
+	}
+
+	alDeleteBuffers(num_buffers, albuf);
+	alDeleteSources(1, &alsrc);
+	alsrc = 0;
+}
diff -r 1ea56011c1ff -r 995191474cc0 prototype/src/audio/stream.h
--- a/prototype/src/audio/stream.h	Wed Sep 19 01:08:41 2012 +0300
+++ b/prototype/src/audio/stream.h	Wed Sep 19 05:22:43 2012 +0300
@@ -3,17 +3,32 @@
 
 #include <thread>
 
+struct AudioStreamBuffer {
+	void *samples;
+	int num_samples;
+	int channels;
+	int sample_rate;
+};
+
 class AudioStream {
 private:
 	std::thread play_thread;
+	bool done, loop;
+	unsigned int poll_interval;
+	unsigned int alsrc;
 
-	virtual bool more_samples() = 0;
+	virtual bool more_samples(AudioStreamBuffer *buf) = 0;
+
+	void poll_loop();
 
 public:
+	AudioStream();
 	virtual ~AudioStream();
 
-	void play();
+	void play(bool loop = false);
 	void stop();
+
+	virtual void rewind() = 0;
 };
 
 #endif	// AUDIO_STREAM_H_