From 16d1f8da5aff85253da11a46a69e5b17743d3915 Mon Sep 17 00:00:00 2001
From: Stephen Birarda <commit@birarda.com>
Date: Wed, 5 Jun 2013 12:31:13 -0700
Subject: [PATCH] pre-enumerate all sources to push buffers when there is only
 one source

---
 audio-mixer/src/PositionalAudioRingBuffer.cpp |  2 +-
 audio-mixer/src/PositionalAudioRingBuffer.h   |  6 ++---
 audio-mixer/src/main.cpp                      | 22 +++++++++++++------
 3 files changed, 19 insertions(+), 11 deletions(-)

diff --git a/audio-mixer/src/PositionalAudioRingBuffer.cpp b/audio-mixer/src/PositionalAudioRingBuffer.cpp
index 5cd856d8c1..e555b7e3d5 100644
--- a/audio-mixer/src/PositionalAudioRingBuffer.cpp
+++ b/audio-mixer/src/PositionalAudioRingBuffer.cpp
@@ -15,7 +15,7 @@ PositionalAudioRingBuffer::PositionalAudioRingBuffer() :
     _position(0.0f, 0.0f, 0.0f),
     _orientation(0.0f, 0.0f, 0.0f, 0.0f),
     _shouldLoopbackForAgent(false),
-    _wasAddedToMix(false)
+    _willBeAddedToMix(false)
 {
     
 }
diff --git a/audio-mixer/src/PositionalAudioRingBuffer.h b/audio-mixer/src/PositionalAudioRingBuffer.h
index 567c6cbf78..d1752fa0bf 100644
--- a/audio-mixer/src/PositionalAudioRingBuffer.h
+++ b/audio-mixer/src/PositionalAudioRingBuffer.h
@@ -22,8 +22,8 @@ public:
     
     bool shouldBeAddedToMix(int numJitterBufferSamples);
     
-    bool wasAddedToMix() const { return _wasAddedToMix; }
-    void setWasAddedToMix(bool wasAddedToMix) { _wasAddedToMix = wasAddedToMix; }
+    bool willBeAddedToMix() const { return _willBeAddedToMix; }
+    void setWillBeAddedToMix(bool willBeAddedToMix) { _willBeAddedToMix = willBeAddedToMix; }
     
     const glm::vec3& getPosition() const { return _position; }
     const glm::quat& getOrientation() const { return _orientation; }
@@ -38,7 +38,7 @@ protected:
     glm::vec3 _position;
     glm::quat _orientation;
     bool _shouldLoopbackForAgent;
-    bool _wasAddedToMix;
+    bool _willBeAddedToMix;
 };
 
 #endif /* defined(__hifi__PositionalAudioRingBuffer__) */
diff --git a/audio-mixer/src/main.cpp b/audio-mixer/src/main.cpp
index f50507a45f..6582fa57bf 100644
--- a/audio-mixer/src/main.cpp
+++ b/audio-mixer/src/main.cpp
@@ -111,7 +111,17 @@ int main(int argc, const char* argv[]) {
     
     gettimeofday(&startTime, NULL);
     
-    while (true) {        
+    while (true) {
+        for (AgentList::iterator agent = agentList->begin(); agent != agentList->end(); agent++) {
+            PositionalAudioRingBuffer* positionalRingBuffer = (PositionalAudioRingBuffer*) agent->getLinkedData();
+            
+            if (positionalRingBuffer && positionalRingBuffer->shouldBeAddedToMix(JITTER_BUFFER_SAMPLES)) {
+                // this is a ring buffer that is ready to go
+                // set its flag so we know to push its buffer when all is said and done
+                positionalRingBuffer->setWillBeAddedToMix(true);
+            }
+        }
+        
         for (AgentList::iterator agent = agentList->begin(); agent != agentList->end(); agent++) {
             if (agent->getType() == AGENT_TYPE_AVATAR) {
                 AvatarAudioRingBuffer* agentRingBuffer = (AvatarAudioRingBuffer*) agent->getLinkedData();
@@ -120,12 +130,10 @@ int main(int argc, const char* argv[]) {
                 memset(clientSamples, 0, sizeof(clientSamples));
                 
                 for (AgentList::iterator otherAgent = agentList->begin(); otherAgent != agentList->end(); otherAgent++) {
-                    if ((otherAgent != agent
-                        && ((PositionalAudioRingBuffer*)otherAgent->getLinkedData())->shouldBeAddedToMix(JITTER_BUFFER_SAMPLES))
-                        || (otherAgent == agent && agentRingBuffer->shouldLoopbackForAgent())) {
+                    if (((PositionalAudioRingBuffer*) otherAgent->getLinkedData())->willBeAddedToMix()
+                        && (otherAgent != agent || (otherAgent == agent && agentRingBuffer->shouldLoopbackForAgent()))) {
                         
                         PositionalAudioRingBuffer* otherAgentBuffer = (PositionalAudioRingBuffer*) otherAgent->getLinkedData();
-                        otherAgentBuffer->setWasAddedToMix(true);
                         
                         float bearingRelativeAngleToSource = 0.0f;
                         float attenuationCoefficient = 1.0f;
@@ -294,14 +302,14 @@ int main(int argc, const char* argv[]) {
         // push forward the next output pointers for any audio buffers we used
         for (AgentList::iterator agent = agentList->begin(); agent != agentList->end(); agent++) {
             PositionalAudioRingBuffer* agentBuffer = (PositionalAudioRingBuffer*) agent->getLinkedData();
-            if (agentBuffer && agentBuffer->wasAddedToMix()) {
+            if (agentBuffer && agentBuffer->willBeAddedToMix()) {
                 agentBuffer->setNextOutput(agentBuffer->getNextOutput() + BUFFER_LENGTH_SAMPLES_PER_CHANNEL);
                 
                 if (agentBuffer->getNextOutput() >= agentBuffer->getBuffer() + RING_BUFFER_LENGTH_SAMPLES) {
                     agentBuffer->setNextOutput(agentBuffer->getBuffer());
                 }
                 
-                agentBuffer->setWasAddedToMix(false);
+                agentBuffer->setWillBeAddedToMix(false);
             }
         }