From 7acfcf6750704b8b76523cf23d64f2291477df6a Mon Sep 17 00:00:00 2001
From: Brad Hefta-Gaub <brad@highfidelity.io>
Date: Wed, 8 Mar 2017 18:15:32 -0800
Subject: [PATCH] fade in and out when opening/closing the noise gate

---
 libraries/audio-client/src/AudioNoiseGate.cpp | 22 ++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/libraries/audio-client/src/AudioNoiseGate.cpp b/libraries/audio-client/src/AudioNoiseGate.cpp
index ac45f98f0b..0ced518097 100644
--- a/libraries/audio-client/src/AudioNoiseGate.cpp
+++ b/libraries/audio-client/src/AudioNoiseGate.cpp
@@ -142,7 +142,11 @@ void AudioNoiseGate::gateSamples(int16_t* samples, int numSamples) {
         _sampleCounter = 0;
         
     }
+
+    bool isOpeningGate = false;
+
     if (samplesOverNoiseGate > NOISE_GATE_WIDTH) {
+        isOpeningGate = !_isOpen;
         _isOpen = true;
         _framesToClose = NOISE_GATE_CLOSE_FRAME_DELAY;
     } else {
@@ -154,7 +158,23 @@ void AudioNoiseGate::gateSamples(int16_t* samples, int numSamples) {
         }
     }
     if (!_isOpen) {
-        memset(samples, 0, numSamples * sizeof(int16_t));
+        if (_closedInLastFrame) {
+            // would be nice to do a little crossfade from silence
+            for (int i = 0; i < numSamples; i++) {
+                float fadedSample = (1.0f - (float)i / (float)numSamples) * (float)samples[i];
+                samples[i] = (int16_t)fadedSample;
+            }
+        } else {
+            memset(samples, 0, numSamples * sizeof(int16_t));
+        }
         _lastLoudness = 0;
     }
+
+    if (isOpeningGate) {
+        // would be nice to do a little crossfade from silence
+        for (int i = 0; i < numSamples; i++) {
+            float fadedSample = ((float)i / (float)numSamples) * (float)samples[i];
+            samples[i] = (int16_t)fadedSample;
+        }
+    }
 }