From 47766d6c6b3b6961dbe676e5aa2d53b8f8456a5a Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Wed, 15 May 2013 15:20:11 -0700
Subject: [PATCH] add methods to AudioInjector to prepare for procedural
 injection

---
 libraries/shared/src/Agent.cpp         |  1 -
 libraries/shared/src/AudioInjector.cpp | 56 +++++++++++++++++++-------
 libraries/shared/src/AudioInjector.h   |  7 +++-
 3 files changed, 47 insertions(+), 17 deletions(-)

diff --git a/libraries/shared/src/Agent.cpp b/libraries/shared/src/Agent.cpp
index f8683fc416..db4170515a 100644
--- a/libraries/shared/src/Agent.cpp
+++ b/libraries/shared/src/Agent.cpp
@@ -74,7 +74,6 @@ Agent::Agent(const Agent &otherAgent) :
         _localSocket = NULL;
     }
     
-    
     if (otherAgent._activeSocket == otherAgent._publicSocket) {
         _activeSocket = _publicSocket;
     } else if (otherAgent._activeSocket == otherAgent._localSocket) {
diff --git a/libraries/shared/src/AudioInjector.cpp b/libraries/shared/src/AudioInjector.cpp
index e08100130e..1417a8ffa7 100644
--- a/libraries/shared/src/AudioInjector.cpp
+++ b/libraries/shared/src/AudioInjector.cpp
@@ -21,30 +21,41 @@ const float SAMPLE_RATE = 22050.0f;
 const float BUFFER_SEND_INTERVAL_USECS = (BUFFER_LENGTH_SAMPLES / SAMPLE_RATE) * 1000000;
 
 AudioInjector::AudioInjector(const char* filename) :
-    _numTotalBytesAudio(0),
     _position(),
     _bearing(0),
-    _attenuationModifier(255) {
-    
+    _attenuationModifier(255),
+    _indexOfNextSlot(0)
+{
     std::fstream sourceFile;
     
     sourceFile.open(filename, std::ios::in | std::ios::binary);
     sourceFile.seekg(0, std::ios::end);
     
-    _numTotalBytesAudio = sourceFile.tellg();
-    if (_numTotalBytesAudio == -1) {
+    int totalBytes = sourceFile.tellg();
+    if (totalBytes == -1) {
         printf("Error reading audio data from file %s\n", filename);
         _audioSampleArray = NULL;
     } else {
-        printf("Read %d bytes from audio file\n", _numTotalBytesAudio);
+        printf("Read %d bytes from audio file\n", totalBytes);
         sourceFile.seekg(0, std::ios::beg);
-        long sizeOfShortArray = _numTotalBytesAudio / 2;
-        _audioSampleArray = new int16_t[sizeOfShortArray];
+        _numTotalSamples = totalBytes / 2;
+        _audioSampleArray = new int16_t[_numTotalSamples];
         
-        sourceFile.read((char *)_audioSampleArray, _numTotalBytesAudio);
+        sourceFile.read((char *)_audioSampleArray, _numTotalSamples);
     }
 }
 
+AudioInjector::AudioInjector(int maxNumSamples) :
+    _numTotalSamples(maxNumSamples),
+    _position(),
+    _bearing(0),
+    _attenuationModifier(255),
+    _indexOfNextSlot(0)
+{
+    _audioSampleArray = new int16_t[maxNumSamples];
+    memset(_audioSampleArray, 0, _numTotalSamples * sizeof(int16_t));
+}
+
 AudioInjector::~AudioInjector() {
     delete[] _audioSampleArray;
 }
@@ -55,6 +66,21 @@ void AudioInjector::setPosition(float* position) {
     _position[2] = position[2];
 }
 
+void AudioInjector::addSample(const int16_t sample) {
+    if (_indexOfNextSlot != _numTotalSamples) {
+        // only add this sample if we actually have space for it
+        _audioSampleArray[_indexOfNextSlot++] = sample;
+    }
+}
+
+void AudioInjector::addSamples(int16_t* sampleBuffer, int numSamples) {
+    if (_audioSampleArray + _indexOfNextSlot + numSamples <= _audioSampleArray + (_numTotalSamples / sizeof(int16_t))) {
+        // only copy the audio from the sample buffer if there's space
+        memcpy(_audioSampleArray + _indexOfNextSlot, sampleBuffer, numSamples * sizeof(int16_t));
+        _indexOfNextSlot += numSamples;
+    }
+}
+
 void AudioInjector::injectAudio(UDPSocket* injectorSocket, sockaddr* destinationSocket) const {
     if (_audioSampleArray != NULL) {
         timeval startTime;
@@ -77,17 +103,17 @@ void AudioInjector::injectAudio(UDPSocket* injectorSocket, sockaddr* destination
         memcpy(currentPacketPtr, &_bearing, sizeof(float));
         currentPacketPtr += sizeof(float);
         
-        for (int i = 0; i < _numTotalBytesAudio; i += BUFFER_LENGTH_BYTES) {
+        for (int i = 0; i < _numTotalSamples; i += BUFFER_LENGTH_SAMPLES) {
             gettimeofday(&startTime, NULL);
             
-            int numBytesToCopy = BUFFER_LENGTH_BYTES;
+            int numSamplesToCopy = BUFFER_LENGTH_SAMPLES;
             
-            if (_numTotalBytesAudio - i < BUFFER_LENGTH_BYTES) {
-                numBytesToCopy = _numTotalBytesAudio - i;
-                memset(currentPacketPtr + numBytesToCopy, 0, BUFFER_LENGTH_BYTES - numBytesToCopy);
+            if (_numTotalSamples - i < BUFFER_LENGTH_SAMPLES) {
+                numSamplesToCopy = _numTotalSamples - i;
+                memset(currentPacketPtr + numSamplesToCopy, 0, BUFFER_LENGTH_BYTES - (numSamplesToCopy * sizeof(int16_t)));
             }
             
-            memcpy(currentPacketPtr, _audioSampleArray + (i / 2), numBytesToCopy);
+            memcpy(currentPacketPtr, _audioSampleArray + i, numSamplesToCopy * sizeof(int16_t));
             
             injectorSocket->send(destinationSocket, dataPacket, sizeof(dataPacket));
             
diff --git a/libraries/shared/src/AudioInjector.h b/libraries/shared/src/AudioInjector.h
index 2515dcfcdc..27223e562c 100644
--- a/libraries/shared/src/AudioInjector.h
+++ b/libraries/shared/src/AudioInjector.h
@@ -17,19 +17,24 @@
 class AudioInjector {
 public:
     AudioInjector(const char* filename);
+    AudioInjector(int maxNumSamples);
     ~AudioInjector();
     
     void setPosition(float* position);
     void setBearing(float bearing) { _bearing = bearing; }
     void setAttenuationModifier(unsigned char attenuationModifier) { _attenuationModifier = attenuationModifier; }
     
+    void addSample(const int16_t sample);
+    void addSamples(int16_t* sampleBuffer, int numSamples);
+    
     void injectAudio(UDPSocket* injectorSocket, sockaddr* destinationSocket) const;
 private:
     int16_t* _audioSampleArray;
-    int _numTotalBytesAudio;
+    int _numTotalSamples;
     float _position[3];
     float _bearing;
     unsigned char _attenuationModifier;
+    int _indexOfNextSlot;
 };
 
 #endif /* defined(__hifi__AudioInjector__) */