From cb5d5dd3a8ba3b879811361406b0d1422478c6cd Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Tue, 11 Nov 2014 16:57:25 -0800
Subject: [PATCH] handle looping via AudioInjectorLocalBuffer

---
 examples/lobby.js                             |  2 +-
 libraries/audio/src/AudioInjector.cpp         |  4 +-
 .../audio/src/AudioInjectorLocalBuffer.cpp    | 45 ++++++++++++++++---
 .../audio/src/AudioInjectorLocalBuffer.h      |  9 +++-
 4 files changed, 47 insertions(+), 13 deletions(-)

diff --git a/examples/lobby.js b/examples/lobby.js
index eb2611fd29..682e8dbd80 100644
--- a/examples/lobby.js
+++ b/examples/lobby.js
@@ -92,7 +92,7 @@ function drawLobby() {
     MyAvatar.attach(HELMET_ATTACHMENT_URL, "Neck", {x: 0, y: 0, z: 0}, Quat.fromPitchYawRollDegrees(0, 0, 0), 1.15);
     
     // start the drone sound
-    currentDrone = Audio.playSound(droneSound, { stereo: true, localOnly: true });
+    currentDrone = Audio.playSound(droneSound, { stereo: true, loop: true, localOnly: true });
   }
 }
 
diff --git a/libraries/audio/src/AudioInjector.cpp b/libraries/audio/src/AudioInjector.cpp
index ddd4f05630..6716d525da 100644
--- a/libraries/audio/src/AudioInjector.cpp
+++ b/libraries/audio/src/AudioInjector.cpp
@@ -83,9 +83,7 @@ void AudioInjector::injectLocally() {
             
             _localBuffer = new AudioInjectorLocalBuffer(_sound->getByteArray(), this);
             _localBuffer->open(QIODevice::ReadOnly);
-            _localBuffer->setIsLooping(_options.loop);
-            
-            qDebug() << "Passing off AudioInjectorLocatBuffer to localAudioInterface";
+            _localBuffer->setShouldLoop(_options.loop);
             
             QMetaObject::invokeMethod(_localAudioInterface, "outputLocalInjector",
                                       Qt::BlockingQueuedConnection,
diff --git a/libraries/audio/src/AudioInjectorLocalBuffer.cpp b/libraries/audio/src/AudioInjectorLocalBuffer.cpp
index 19c92276f9..bdf084091d 100644
--- a/libraries/audio/src/AudioInjectorLocalBuffer.cpp
+++ b/libraries/audio/src/AudioInjectorLocalBuffer.cpp
@@ -14,8 +14,9 @@
 AudioInjectorLocalBuffer::AudioInjectorLocalBuffer(const QByteArray& rawAudioArray, QObject* parent) :
     QIODevice(parent),
     _rawAudioArray(rawAudioArray),
-    _isLooping(false),
-    _isStopped(false)
+    _shouldLoop(false),
+    _isStopped(false),
+    _currentOffset(0)
 {
     
 }
@@ -27,17 +28,47 @@ void AudioInjectorLocalBuffer::stop() {
 
 qint64 AudioInjectorLocalBuffer::readData(char* data, qint64 maxSize) {
     if (!_isStopped) {
-        int bytesToEnd = _rawAudioArray.size() - pos();
         
-        int bytesToRead = maxSize;
+        // first copy to the end of the raw audio
+        int bytesToEnd = _rawAudioArray.size() - _currentOffset;
+        
+        int bytesRead = maxSize;
         
         if (maxSize > bytesToEnd) {
-            bytesToRead = bytesToEnd;
+            bytesRead = bytesToEnd;
         }
         
-        memcpy(data, _rawAudioArray.data() + pos(), bytesToRead);
-        return bytesToRead;
+        memcpy(data, _rawAudioArray.data() + _currentOffset, bytesRead);
+        
+        // now check if we are supposed to loop and if we can copy more from the beginning
+        if (_shouldLoop && maxSize != bytesRead) {
+            bytesRead += recursiveReadFromFront(data + bytesRead, maxSize - bytesRead);
+        } else {
+            _currentOffset += bytesRead;
+        }
+        
+        return bytesRead;
     } else {
         return 0;
     }
+}
+
+qint64 AudioInjectorLocalBuffer::recursiveReadFromFront(char* data, qint64 maxSize) {
+    // see how much we can get in this pass
+    int bytesRead = maxSize;
+    
+    if (bytesRead > _rawAudioArray.size()) {
+        bytesRead = _rawAudioArray.size();
+    }
+    
+    // copy that amount
+    memcpy(data, _rawAudioArray.data(), bytesRead);
+    
+    // check if we need to call ourselves again and pull from the front again
+    if (bytesRead < maxSize) {
+        return bytesRead + recursiveReadFromFront(data, maxSize);
+    } else {
+        _currentOffset = bytesRead;
+        return bytesRead;
+    }
 }
\ No newline at end of file
diff --git a/libraries/audio/src/AudioInjectorLocalBuffer.h b/libraries/audio/src/AudioInjectorLocalBuffer.h
index 6d234066ef..8b32c6fbc7 100644
--- a/libraries/audio/src/AudioInjectorLocalBuffer.h
+++ b/libraries/audio/src/AudioInjectorLocalBuffer.h
@@ -24,12 +24,17 @@ public:
     qint64 readData(char* data, qint64 maxSize);
     qint64 writeData(const char* data, qint64 maxSize) { return 0; }
     
-    void setIsLooping(bool isLooping) { _isLooping = isLooping; }
+    void setShouldLoop(bool shouldLoop) { _shouldLoop = shouldLoop; }
     
 private:
+    
+    qint64 recursiveReadFromFront(char* data, qint64 maxSize);
+    
     QByteArray _rawAudioArray;
-    bool _isLooping;
+    bool _shouldLoop;
     bool _isStopped;
+    
+    int _currentOffset;
 };
 
 #endif // hifi_AudioInjectorLocalBuffer_h
\ No newline at end of file