From 7a4bdc1779affed20fc0111689211bb2d5b23062 Mon Sep 17 00:00:00 2001
From: Ken Cooke <ken@highfidelity.io>
Date: Thu, 14 Jul 2016 11:30:55 -0700
Subject: [PATCH] enable in Interface and AudioMixer, by passing distance
 between source and listener

---
 assignment-client/src/audio/AudioMixer.cpp | 14 +++++++++-----
 libraries/audio-client/src/AudioClient.cpp |  8 ++++----
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/assignment-client/src/audio/AudioMixer.cpp b/assignment-client/src/audio/AudioMixer.cpp
index 24893ad1b6..08e6e029a0 100644
--- a/assignment-client/src/audio/AudioMixer.cpp
+++ b/assignment-client/src/audio/AudioMixer.cpp
@@ -193,8 +193,12 @@ void AudioMixer::addStreamToMixForListeningNodeWithStream(AudioMixerClientData&
     // check if this is a server echo of a source back to itself
     bool isEcho = (&streamToAdd == &listeningNodeStream);
 
-    // figure out the gain for this source at the listener
     glm::vec3 relativePosition = streamToAdd.getPosition() - listeningNodeStream.getPosition();
+
+    // figure out the distance between source and listener
+    float distance = glm::max(glm::length(relativePosition), EPSILON);
+
+    // figure out the gain for this source at the listener
     float gain = gainForSource(streamToAdd, listeningNodeStream, relativePosition, isEcho);
 
     // figure out the azimuth to this source at the listener
@@ -240,7 +244,7 @@ void AudioMixer::addStreamToMixForListeningNodeWithStream(AudioMixerClientData&
 
                 // this is not done for stereo streams since they do not go through the HRTF
                 static int16_t silentMonoBlock[AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL] = {};
-                hrtf.renderSilent(silentMonoBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, 0.0f, gain,
+                hrtf.renderSilent(silentMonoBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
                                   AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
 
                 ++_hrtfSilentRenders;;
@@ -287,7 +291,7 @@ void AudioMixer::addStreamToMixForListeningNodeWithStream(AudioMixerClientData&
         // silent frame from source
 
         // we still need to call renderSilent via the HRTF for mono source
-        hrtf.renderSilent(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, 0.0f, gain,
+        hrtf.renderSilent(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
                           AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
 
         ++_hrtfSilentRenders;
@@ -300,7 +304,7 @@ void AudioMixer::addStreamToMixForListeningNodeWithStream(AudioMixerClientData&
         // the mixer is struggling so we're going to drop off some streams
 
         // we call renderSilent via the HRTF with the actual frame data and a gain of 0.0
-        hrtf.renderSilent(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, 0.0f, 0.0f,
+        hrtf.renderSilent(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, distance, 0.0f,
                           AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
 
         ++_hrtfStruggleRenders;
@@ -311,7 +315,7 @@ void AudioMixer::addStreamToMixForListeningNodeWithStream(AudioMixerClientData&
     ++_hrtfRenders;
 
     // mono stream, call the HRTF with our block and calculated azimuth and gain
-    hrtf.render(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, 0.0f, gain,
+    hrtf.render(streamBlock, _mixedSamples, HRTF_DATASET_INDEX, azimuth, distance, gain,
                 AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
 }
 
diff --git a/libraries/audio-client/src/AudioClient.cpp b/libraries/audio-client/src/AudioClient.cpp
index bc29ba5c96..50039ba668 100644
--- a/libraries/audio-client/src/AudioClient.cpp
+++ b/libraries/audio-client/src/AudioClient.cpp
@@ -882,13 +882,13 @@ void AudioClient::mixLocalAudioInjectors(int16_t* inputBuffer) {
                     
                 } else {
 
-                    // calculate gain and azimuth for hrtf
+                    // calculate distance, gain and azimuth for hrtf
                     glm::vec3 relativePosition = injector->getPosition() - _positionGetter();
+                    float distance = glm::max(glm::length(relativePosition), EPSILON);
                     float gain = gainForSource(relativePosition, injector->getVolume()); 
-                    float azimuth = azimuthForSource(relativePosition); 
+                    float azimuth = azimuthForSource(relativePosition);         
                 
-                
-                    injector->getLocalHRTF().render(_scratchBuffer, _hrtfBuffer, 1, azimuth, 0.0f, gain, AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
+                    injector->getLocalHRTF().render(_scratchBuffer, _hrtfBuffer, 1, azimuth, distance, gain, AudioConstants::NETWORK_FRAME_SAMPLES_PER_CHANNEL);
                 }
             
             } else {