#64 - Workaround for Spectrogram band 0

Aural.xcodeproj/project.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict/>
+</plist>

Aural.xcodeproj/project.xcworkspace/xcuserdata/kven.xcuserdatad/WorkspaceSettings.xcsettings

@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>BuildLocationStyle</key>
+	<string>UseAppPreferences</string>
+	<key>CustomBuildLocationType</key>
+	<string>RelativeToDerivedData</string>
+	<key>DerivedDataLocationStyle</key>
+	<string>Default</string>
+	<key>ShowSharedSchemesAutomaticallyEnabled</key>
+	<true/>
+</dict>
+</plist>

Source/ObjectGraph.swift

@@ -136,6 +136,8 @@ class ObjectGraph {
 
     let mediaKeyHandler: MediaKeyHandler
 
+    let fft: FFT = FFT()
+
     @available(OSX 10.12.2, *)
     lazy var remoteControlManager: RemoteControlManager = RemoteControlManager(playbackInfo: playbackInfoDelegate, audioGraph: audioGraphDelegate,
                                                                                sequencer: sequencerDelegate, preferences: preferences)

Source/UI/Visualizer/FFT/FFT.swift

@@ -85,11 +85,11 @@ class FFT: Destroyable {
         windowSize = bufferSizePOT
         windowSize_vDSPLength = vDSP_Length(windowSize)
 
-        transferBuffer = UnsafeMutablePointer<Float>.allocate(capacity: windowSize)
+        transferBuffer = .allocate(capacity: windowSize)
         window = [Float](repeating: 0, count: windowSize)
 
         magnitudes = [Float](repeating: 0, count: halfBufferSize)
-        normalizedMagnitudes = UnsafeMutablePointer<Float>.allocate(capacity: halfBufferSize)
+        normalizedMagnitudes = .allocate(capacity: halfBufferSize)
     }
 
     func analyze(buffer: AudioBufferList) {

Source/UI/Visualizer/FFT/SpectrogramFFTData.swift

@@ -27,9 +27,17 @@ class SpectrogramFFTData {
 
     func update(with fft: FFT) {
 
-        for band in bands {
+        let alternateLogicForBand0: Bool = fft.bufferSize < objectGraph.audioGraph.visualizationAnalysisBufferSize
+
+        for (index, band) in bands.enumerated() {
+
+            if alternateLogicForBand0, index == 0 {
+                maxVal = (fft.normalizedMagnitudes[0] + fft.normalizedMagnitudes[1]) / 2
+
+            } else {
+                vDSP_maxv(fft.normalizedMagnitudes.advanced(by: band.minIndex), 1, &maxVal, band.indexCount)
+            }
 
-            vDSP_maxv(fft.normalizedMagnitudes.advanced(by: band.minIndex), 1, &maxVal, band.indexCount)
             band.maxVal = maxVal.clamp(to: fft.magnitudeRange)
         }
     }

Source/UI/Visualizer/Views/DiscoBall.swift

@@ -40,6 +40,10 @@ class DiscoBall: AuralSCNView, VisualizerViewProtocol {
 
     let textureImage: NSImage = NSImage(named: "DiscoBall")!
 
+    func setUp(with fft: FFT) {
+        data.setUp(for: fft)
+    }
+
     func presentView(with fft: FFT) {
 
         data.setUp(for: fft)

Source/UI/Visualizer/Views/Spectrogram.swift

@@ -52,6 +52,10 @@ class Spectrogram: SKView, VisualizerViewProtocol {
         }
     }
 
+    func setUp(with fft: FFT) {
+        data.setUp(fft: fft, numberOfBands: numberOfBands)
+    }
+
     func presentView(with fft: FFT) {
 
         data.setUp(fft: fft, numberOfBands: numberOfBands)

Source/UI/Visualizer/Views/Supernova.swift

@@ -22,6 +22,10 @@ class Supernova: SKView, VisualizerViewProtocol {
 
     private var glowWidth: CGFloat = 50
 
+    func setUp(with fft: FFT) {
+        data.setUp(for: fft)
+    }
+
     func presentView(with fft: FFT) {
 
         data.setUp(for: fft)

Source/UI/Visualizer/Views/VisualizerViewProtocol.swift

@@ -19,6 +19,8 @@ protocol VisualizerViewProtocol {
 
     func dismissView()
 
+    func setUp(with fft: FFT)
+
     func update(with fft: FFT)
 
     func setColors(startColor: NSColor, endColor: NSColor)

Source/UI/Visualizer/Visualizer.swift

@@ -18,7 +18,7 @@ typealias VisualizerRenderCallback = () -> Void
 class Visualizer: AudioGraphRenderObserverProtocol, Destroyable {
 
     // Fast Fourier Transform
-    let fft: FFT = FFT()
+    let fft: FFT = objectGraph.fft
 
     private var audioGraph: AudioGraphDelegateProtocol = objectGraph.audioGraphDelegate
     private var normalDeviceBufferSize: Int = 0
@@ -65,7 +65,11 @@ class Visualizer: AudioGraphRenderObserverProtocol, Destroyable {
         normalDeviceBufferSize = newDeviceBufferSize
 
         if newDeviceBufferSize != audioGraph.visualizationAnalysisBufferSize {
+
             audioGraph.outputDeviceBufferSize = audioGraph.visualizationAnalysisBufferSize
+
+            fft.setUp(sampleRate: Float(audioGraph.outputDeviceSampleRate),
+                      bufferSize: audioGraph.outputDeviceBufferSize)
         }
     }
 

Source/UI/Visualizer/VisualizerWindowController.swift

@@ -39,6 +39,14 @@ class VisualizerWindowController: NSWindowController, NSWindowDelegate, Destroya
 
     private lazy var uiState: VisualizerUIState = objectGraph.visualizerUIState
 
+    private(set) lazy var messenger = Messenger(for: self)
+
+    override func windowDidLoad() {
+
+        super.windowDidLoad()
+        messenger.subscribeAsync(to: .audioGraph_outputDeviceChanged, handler: audioOutputDeviceChanged)
+    }
+
     override func awakeFromNib() {
 
         window?.delegate = self
@@ -58,6 +66,7 @@ class VisualizerWindowController: NSWindowController, NSWindowDelegate, Destroya
 
         close()
         visualizer.destroy()
+        messenger.unsubscribeFromAll()
     }
 
     override func showWindow(_ sender: Any?) {
@@ -150,6 +159,14 @@ class VisualizerWindowController: NSWindowController, NSWindowDelegate, Destroya
         }
     }
 
+    // When the audio output device changes, restart the audio engine and continue playback as before.
+    func audioOutputDeviceChanged() {
+
+        allViews.forEach {
+            $0.setUp(with: objectGraph.fft)
+        }
+    }
+
     @IBAction func closeWindowAction(_ sender: Any) {
         close()
     }