From f21bc3f4aea8c5caa2e321642caa71435e5caf8a Mon Sep 17 00:00:00 2001
From: reuk <reuk@users.noreply.github.com>
Date: Tue, 28 Feb 2023 12:32:33 +0000
Subject: [PATCH] AudioSynthesiserDemo: Show output rather than input in
 waveform view

---
 examples/Audio/AudioSynthesiserDemo.h | 64 +++++++++++++++++++++------
 1 file changed, 50 insertions(+), 14 deletions(-)

diff --git a/examples/Audio/AudioSynthesiserDemo.h b/examples/Audio/AudioSynthesiserDemo.h
index 11891911b6..bd8d7cf38b 100644
--- a/examples/Audio/AudioSynthesiserDemo.h
+++ b/examples/Audio/AudioSynthesiserDemo.h
@@ -55,8 +55,6 @@
 /** Our demo synth sound is just a basic sine wave.. */
 struct SineWaveSound : public SynthesiserSound
 {
-    SineWaveSound() {}
-
     bool appliesToNote (int /*midiNoteNumber*/) override    { return true; }
     bool appliesToChannel (int /*midiChannel*/) override    { return true; }
 };
@@ -65,8 +63,6 @@ struct SineWaveSound : public SynthesiserSound
 /** Our demo synth voice just plays a sine wave.. */
 struct SineWaveVoice  : public SynthesiserVoice
 {
-    SineWaveVoice() {}
-
     bool canPlaySound (SynthesiserSound* sound) override
     {
         return dynamic_cast<SineWaveSound*> (sound) != nullptr;
@@ -241,6 +237,51 @@ struct SynthAudioSource  : public AudioSource
     Synthesiser synth;
 };
 
+//==============================================================================
+class Callback : public AudioIODeviceCallback
+{
+public:
+    Callback (AudioSourcePlayer& playerIn, LiveScrollingAudioDisplay& displayIn)
+        : player (playerIn), display (displayIn) {}
+
+    void audioDeviceIOCallbackWithContext (const float* const* inputChannelData,
+                                           int numInputChannels,
+                                           float* const* outputChannelData,
+                                           int numOutputChannels,
+                                           int numSamples,
+                                           const AudioIODeviceCallbackContext& context) override
+    {
+        player.audioDeviceIOCallbackWithContext (inputChannelData,
+                                                 numInputChannels,
+                                                 outputChannelData,
+                                                 numOutputChannels,
+                                                 numSamples,
+                                                 context);
+        display.audioDeviceIOCallbackWithContext (outputChannelData,
+                                                  numOutputChannels,
+                                                  nullptr,
+                                                  0,
+                                                  numSamples,
+                                                  context);
+    }
+
+    void audioDeviceAboutToStart (AudioIODevice* device) override
+    {
+        player.audioDeviceAboutToStart (device);
+        display.audioDeviceAboutToStart (device);
+    }
+
+    void audioDeviceStopped() override
+    {
+        player.audioDeviceStopped();
+        display.audioDeviceStopped();
+    }
+
+private:
+    AudioSourcePlayer& player;
+    LiveScrollingAudioDisplay& display;
+};
+
 //==============================================================================
 class AudioSynthesiserDemo  : public Component
 {
@@ -259,19 +300,13 @@ public:
         sampledButton.onClick = [this] { synthAudioSource.setUsingSampledSound(); };
 
         addAndMakeVisible (liveAudioDisplayComp);
-        audioDeviceManager.addAudioCallback (&liveAudioDisplayComp);
         audioSourcePlayer.setSource (&synthAudioSource);
 
        #ifndef JUCE_DEMO_RUNNER
-        RuntimePermissions::request (RuntimePermissions::recordAudio,
-                                     [this] (bool granted)
-                                     {
-                                         int numInputChannels = granted ? 2 : 0;
-                                         audioDeviceManager.initialise (numInputChannels, 2, nullptr, true, {}, nullptr);
-                                     });
+        audioDeviceManager.initialise (0, 2, nullptr, true, {}, nullptr);
        #endif
 
-        audioDeviceManager.addAudioCallback (&audioSourcePlayer);
+        audioDeviceManager.addAudioCallback (&callback);
         audioDeviceManager.addMidiInputDeviceCallback ({}, &(synthAudioSource.midiCollector));
 
         setOpaque (true);
@@ -282,8 +317,7 @@ public:
     {
         audioSourcePlayer.setSource (nullptr);
         audioDeviceManager.removeMidiInputDeviceCallback ({}, &(synthAudioSource.midiCollector));
-        audioDeviceManager.removeAudioCallback (&audioSourcePlayer);
-        audioDeviceManager.removeAudioCallback (&liveAudioDisplayComp);
+        audioDeviceManager.removeAudioCallback (&callback);
     }
 
     //==============================================================================
@@ -318,5 +352,7 @@ private:
 
     LiveScrollingAudioDisplay liveAudioDisplayComp;
 
+    Callback callback { audioSourcePlayer, liveAudioDisplayComp };
+
     JUCE_DECLARE_NON_COPYABLE_WITH_LEAK_DETECTOR (AudioSynthesiserDemo)
 };