Minor adjustments to documentation and minor adjust to SpectrogramFla…

…tView (AudioKit#86)

* Added AudioKitUI.docc with a markdown so Documentation can easily be built for iOS.

* Minor adjustments to documentation

* Fixed title in main docc article so it shows directly on home page of AudioKitUI

* Added links to other UI related frameworks of AudioKit

* Fixed amplitude. It was not sensitive enough, showing full amplitude at half the intensity.

* Cleanup of commented .borders

* First quadrant flipping only once in the body

* Trailing white space

README.md

@@ -32,10 +32,12 @@ Just like AudioKit, the example project for AudioKitUI is the [AudioKit Cookbook
 
 ## More!
 
-Because some user interfaces are quite complex, and don't really have AudioKit as a dependency, we will be putting them in other repositories under the AudioKit umbrella. 
-
-### Piano Roll 
-
-[https://github.com/AudioKit/PianoRoll](https://github.com/AudioKit/PianoRoll)
-
-<img src="https://raw.githubusercontent.com/AudioKit/PianoRoll/main/Sources/PianoRoll/PianoRoll.docc/Resources/screenshot.png" alt="piano roll screenshot" style="width:75%;">
+Because some user interfaces are quite complex, and don't really have AudioKit as a dependency, they are in other repositories under the AudioKit umbrella:
+
+* Controls: SwiftUI Knobs, Sliders, X-Y Pads, and more [github.com/AudioKit/Controls](https://github.com/AudioKit/Controls)
+* Flow: Generic node graph editor [github.com/AudioKit/Flow](https://github.com/AudioKit/Flow) 
+* Keyboard: SwiftUI music keyboard [github.com/AudioKit/Keyboard](https://github.com/AudioKit/Keyboard)
+* Piano Roll: Touch oriented piano roll [github.com/AudioKit/PianoRoll](https://github.com/AudioKit/PianoRoll)
+* PianoRollEditor: Logic Pro like piano roll editor [github.com/AudioKit/PianoRollEditor](https://github.com/AudioKit/PianoRollEditor)
+* MIDITrackView: View representing a MIDI Track [github.com/AudioKit/MIDITrackView](https://github.com/AudioKit/MIDITrackView)
+* Waveform: GPU accelerated waveform view [github.com/AudioKit/Waveform](https://github.com/AudioKit/Waveform)

Sources/AudioKitUI/AudioKitUI.docc/AudioKitUI.md

@@ -0,0 +1,31 @@
+# ``AudioKitUI``
+
+@Metadata {
+    @TitleHeading("AudioKit User Interfaces")
+}
+
+Waveform plots and controls that can be used to jump start your AudioKit-powered app.
+
+## Requirements
+
+We use SwiftUI so you need to target iOS 13+ and macOS 10.15+.
+
+## Installation via Swift Package Manager
+
+To add AudioKitUI to your Xcode project, select File -> Swift Packages -> Add Package Dependency. Enter `https://github.com/AudioKit/AudioKitUI` for the URL.
+
+## Examples
+
+Just like AudioKit, the example project for AudioKitUI is the [AudioKit Cookbook](https://github.com/AudioKit/Cookbook/).
+
+## More
+
+Because some user interfaces are quite complex, and don't really have AudioKit as a dependency, they are in other repositories under the AudioKit umbrella. 
+
+- term Controls: SwiftUI Knobs, Sliders, X-Y Pads, and more [github.com/AudioKit/Controls](https://github.com/AudioKit/Controls)
+- term Flow: Generic node graph editor [github.com/AudioKit/Flow](https://github.com/AudioKit/Flow) 
+- term Keyboard: SwiftUI music keyboard [github.com/AudioKit/Keyboard](https://github.com/AudioKit/Keyboard)
+- term Piano Roll: Touch oriented piano roll [github.com/AudioKit/PianoRoll](https://github.com/AudioKit/PianoRoll)
+- term PianoRollEditor: Logic Pro like piano roll editor [github.com/AudioKit/PianoRollEditor](https://github.com/AudioKit/PianoRollEditor)
+- term MIDITrackView: View representing a MIDI Track [github.com/AudioKit/MIDITrackView](https://github.com/AudioKit/MIDITrackView)
+- term Waveform: GPU accelerated waveform view [github.com/AudioKit/Waveform](https://github.com/AudioKit/Waveform)

Sources/AudioKitUI/Controls/ADSRView.swift

@@ -7,6 +7,7 @@ import AVFoundation
 import UIKit
 
 /// A click and draggable view of an ADSR Envelope (Atttack, Decay, Sustain, Release)
+///
 /// All values are normalised 0->1, so scale them how you would like in your callback
 
 @IBDesignable public class ADSRView: UIView {

Sources/AudioKitUI/Helpers/MorphableShape.swift

@@ -31,17 +31,16 @@ struct MorphableShape: Shape {
     }
 }
 
-// MARK: Path extension
-
+/// Return points at a given offset and create AnimatableVector for control points
 extension Path {
-    // return point at the curve
+    /// return point at the curve
     func point(at offset: CGFloat) -> CGPoint {
         let limitedOffset = min(max(offset, 0), 1)
         guard limitedOffset > 0 else { return cgPath.currentPoint }
         return trimmedPath(from: 0, to: limitedOffset).cgPath.currentPoint
     }
 
-    // return control points along the path
+    /// return control points along the path
     func controlPoints(count: Int) -> AnimatableVector {
         var retPoints = [Double]()
         for index in 0 ..< count {

Sources/AudioKitUI/Visualizations/SpectrogramFlatView/SpectrogramFlatView.swift

@@ -120,14 +120,11 @@ public struct SpectrogramFlatView: View {
                     }
                 HStack(spacing: 0.0) {
                     ForEach(spectrogram.slices.items) { slice in
-                        // flip it as the slice was drawn in the first quadrant
-                        slice.scaleEffect(x: 1, y: -1)
-                        // .border(.green, width: 2.0)
+                        slice
                     }
                     // flip it so the new slices come in right and move to the left
                     .scaleEffect(x: -1, y: 1)
                 }
-                // .border(.red, width: 5.0)
                 .frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .trailing)
             }.onAppear {
                 spectrogram.sliceSize = calcSliceSize(fromFrameSize: geometry.size)

Sources/AudioKitUI/Visualizations/SpectrogramFlatView/SpectrogramModel.swift

@@ -20,7 +20,7 @@ struct SpectrogramFFTMetaData {
     //            New data comes roughly  5.5 times per second, each 186ms.  
     // Choose a higher value when you want to analyze low frequencies, 
     // choose a lower value when you want fast response and high frame rate on display.
-    let fftSize = 2048
+    let fftSize: UInt32 = 2048
 
     // Lowest and highest frequencies shown. 
     // We use 48Hz, which is a bit lower than G1. A1 would be 440Hz/8 = 55Hz.  
@@ -137,7 +137,7 @@ class SpectrogramFlatModel: ObservableObject {
         // main thread and user while doing the work
         if node !== self.node {
             self.node = node
-            nodeTap = FFTTap(node, bufferSize: UInt32(nodeMetaData.fftSize * 2), callbackQueue: .global()) { fftData in
+            nodeTap = FFTTap(node, bufferSize: nodeMetaData.fftSize * 2, callbackQueue: .global()) { fftData in
                 self.pushData(fftData)
             }
             // normalization would mean that on each slice, the loudest would have 

Sources/AudioKitUI/Visualizations/SpectrogramFlatView/SpectrogramSlice.swift

@@ -88,6 +88,8 @@ struct SpectrogramSlice: View, Identifiable {
 
     public var body: some View {
         return Image(uiImage: cachedUIImage).resizable()
+            // flip it as the slice was drawn in the first quadrant
+            .scaleEffect(x: 1, y: -1)
     }
 
     // This code draws in the first quadrant, it's much easier to understand 
@@ -222,7 +224,7 @@ struct SpectrogramSlice: View, Identifiable {
             let real = fftFloats[index-1].isNaN ? 0.0 : fftFloats[index-1]
             let imaginary = fftFloats[index].isNaN ? 0.0 : fftFloats[index]
             let frequencyForBin = fftMetaData.sampleRate * 0.5 * Double(index * 2) / Double(fftFloats.count * 2)
-            var squared = real * real + imaginary * imaginary
+            var squared: Float = real * real + imaginary * imaginary
 
             // if the frequency is higher as we need: continue
             // we don't filter low frequencies, they are all pushed to the queue
@@ -257,7 +259,8 @@ struct SpectrogramSlice: View, Identifiable {
                     maxSquared = 0.0
                 }
             }
-            let amplitude = Double(10 * log10(4 * squared / (Float(fftMetaData.fftSize) * Float(fftMetaData.fftSize))))
+            let fftBins = CGFloat(fftMetaData.fftSize)
+            let amplitude = Double(10 * log10(4 * CGFloat(squared) / fftBins * fftBins))
             points.append(CGPoint(x: frequencyChosen, y: amplitude))
         }
         return points
@@ -285,7 +288,7 @@ struct SpectrogramSlice_Previews: PreviewProvider {
                             CGPoint(x: 8800, y: -40),
                             CGPoint(x: 8000, y: -10)],
                          fftMetaData: SpectrogramFFTMetaData()
-        ).scaleEffect(x: 1, y: -1)
+        )
     }
 }
 

Sources/AudioKitUI/Visualizations/SpectrogramFlatView/UIColor+intermediate.swift

@@ -5,11 +5,15 @@
 import Foundation
 import UIKit
 
-/// usage You can use it to get an intermediate color between two or more colors:
-/// let color = [.green, .yellow, .red].intermediate(0.7)
-/// inspired by 
-/// https://stackoverflow.com/questions/15032562/ios-find-color-at-point-between-two-colors/59996029#59996029
+/// Get an intermediate color between two or more colors
+/// 
+/// Example: `let color = [.green, .yellow, .red].intermediate(0.7)`
+///
+/// inspired by [stackoverflow 15032562 answer Nikaaner](https://stackoverflow.com/questions/15032562/ios-find-color-at-point-between-two-colors/59996029#59996029)
 extension Array where Element: UIColor {
+    /// Get an intermediate color between two or more colors
+    /// 
+    /// Example: `let color = [.green, .yellow, .red].intermediate(0.7)`
     public func intermediate(_ percentage: CGFloat) -> UIColor {
         let percentage = Swift.max(Swift.min(percentage, 1), 0)
         switch percentage {