Update README.md

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Example/Example/Base.lproj/Main.storyboard

@@ -43,7 +43,7 @@
                                 <rect key="frame" x="20" y="93" width="374" height="32"/>
                                 <segments>
                                     <segment title="Orange"/>
-                                    <segment title="Magenta"/>
+                                    <segment title="Red"/>
                                     <segment title="Green"/>
                                     <segment title="Brown"/>
                                     <segment title="Cyan"/>
@@ -84,11 +84,18 @@
                         <viewLayoutGuide key="safeArea" id="aXm-cj-1eD"/>
                     </view>
                     <navigationItem key="navigationItem" id="XgG-ZM-i9d">
-                        <barButtonItem key="leftBarButtonItem" title="Share" id="so2-d3-VCF">
-                            <connections>
-                                <action selector="share:" destination="0zP-ee-W0J" id="uNU-bV-PaS"/>
-                            </connections>
-                        </barButtonItem>
+                        <leftBarButtonItems>
+                            <barButtonItem title="Share" id="so2-d3-VCF">
+                                <connections>
+                                    <action selector="share:" destination="0zP-ee-W0J" id="uNU-bV-PaS"/>
+                                </connections>
+                            </barButtonItem>
+                            <barButtonItem title="Config" id="33c-Ng-bhx">
+                                <connections>
+                                    <action selector="changeConfig:" destination="0zP-ee-W0J" id="izA-qU-8it"/>
+                                </connections>
+                            </barButtonItem>
+                        </leftBarButtonItems>
                         <rightBarButtonItems>
                             <barButtonItem title="Camera" id="Ckh-RB-Kad">
                                 <connections>

Example/Example/Info.plist

@@ -22,8 +22,8 @@
 	<true/>
 	<key>NSAppleMusicUsageDescription</key>
 	<string>To scan roundcodes</string>
-  <key>NSPhotoLibraryAddUsageDescription</key>
-  <string>To save RoundCode images</string>
+	<key>NSPhotoLibraryAddUsageDescription</key>
+	<string>To save RoundCode images</string>
 	<key>NSCameraUsageDescription</key>
 	<string>To scan roundcodes</string>
 	<key>UIApplicationSceneManifest</key>
@@ -64,5 +64,7 @@
 		<string>UIInterfaceOrientationLandscapeLeft</string>
 		<string>UIInterfaceOrientationLandscapeRight</string>
 	</array>
+	<key>UIUserInterfaceStyle</key>
+	<string>Light</string>
 </dict>
 </plist>

Example/Example/ViewController.swift

@@ -30,17 +30,39 @@ class ViewController: UIViewController {
   @IBOutlet weak var messageLabel: UILabel!
   var coder = RCCoder()
   var image = RCImage(message: "")
-  let colors: [[UIColor]] = [[.orange, .gray], [.orange, .magenta], [.systemGreen, .systemBlue], [.orange, .brown], [.purple, .cyan]]
+  let colors: [[UIColor]] = [[.orange, .magenta], [.systemPink, .systemTeal], [.systemTeal, .systemGreen], [.orange, .brown], [.purple, .cyan]]
   var isScanningFromLibrary = false
 }
 
 extension ViewController {
   
-  override func viewDidLoad() {
-    super.viewDidLoad()
-    image.isTransparent = true
+  @IBAction func changeConfig(_ sender: Any) {
+    textField.text = ""
+    image.message = ""
+    imageView.image = try? coder.encode(image)
+    let vc = UIAlertController(title: "Select Configuration", message: nil, preferredStyle: .actionSheet)
+    let uuidAction = UIAlertAction(title: "UUID", style: .default) { _ in
+      self.coder = RCCoder(configuration: .uuidConfiguration)
+    }
+    let numericAction = UIAlertAction(title: "Numeric", style: .default) { _ in
+      self.coder = RCCoder(configuration: .numericConfiguration)
+    }
+    let shortAction = UIAlertAction(title: "Short", style: .default) { _ in
+      self.coder = RCCoder(configuration: .shortConfiguration)
+    }
+    let defaultAction = UIAlertAction(title: "Default", style: .default) { _ in
+      self.coder = RCCoder(configuration: .defaultConfiguration)
+    }
+    let cancelAction = UIAlertAction(title: "Cancel", style: .cancel)
+    vc.addAction(uuidAction)
+    vc.addAction(numericAction)
+    vc.addAction(shortAction)
+    vc.addAction(defaultAction)
+    vc.addAction(cancelAction)
+    present(vc, animated: true)
   }
   
+  
   @IBAction func scanImage(_ sender: Any) {
     isScanningFromLibrary = true
     let vc = UIImagePickerController()
@@ -53,18 +75,18 @@ extension ViewController {
   
   @IBAction func scan(_ sender: Any) {
     let vc = RCCameraViewController()
+    coder.scanningMode  = .lightBackground
+    vc.coder = coder
     vc.delegate = self
     present(vc, animated: true)
   }
   
   @IBAction func share(_ sender: Any) {
     image.size = 1000
-    image.isTransparent = false
     image.contentInsets = UIEdgeInsets(top: 50, left: 50, bottom: 50, right: 50)
     let uiImage = try? coder.encode(image)
     image.size = 300
     image.contentInsets = UIEdgeInsets(top: 8, left: 8, bottom: 8, right: 8)
-    image.isTransparent = true
     let vc = UIActivityViewController.init(activityItems: [uiImage!], applicationActivities: nil)
     present(vc, animated: true)
   }

README.md

@@ -5,10 +5,8 @@
 [![Twitter: @aslanyanhaik](https://img.shields.io/badge/Contact-Twitter-blue.svg?style=flat)](https://twitter.com/aslanyanhaik)
 
 
-
-RoundCode is a Facebook messenger like custom QR code with lots of customization. 
-
-In addition to encoder the RoundCode also includes convenient camera scanner and decoder.
+RoundCode is custom circular QR code with lots of customization. 
+Similar to Facebook messenger and Apple's App Clip Codes the RoundCode includes convenient camera scanner and decoder.
 
 <h3 align="center">
 <img src="appearance.png" alt="Different styles of RoundCode for iOS"/>
@@ -81,14 +79,14 @@ You can also decode a UIImage like this
 
 ```swift
 let coder = RCCoder()
-  do {
-    messageLabel.text = try coder.decode(UIImage(named: code)!)
-  } catch {
-    //handle errors
-  }
+do {
+  messageLabel.text = try coder.decode(UIImage(named: code)!)
+} catch {
+  //handle errors
+}
 ```
 
-### Appearance
+## Appearance
 
 You can change the appearance like this
 
@@ -100,10 +98,14 @@ image.size = 300
 image.gradientType = .linear(angle: CGFloat.pi)
 image.tintColors = [.red, .black]
 ```
+If image is on dark background you should change scanning mode to `darkBackground`
 
-⚠️ When choosing colors or transparent background you should keep in mind that decoder will detect the code on light background with dark colors ⚠️
+```swift
+let coder = RCCoder()
+coder.scanningMode = .darkBackground
+```
 
-### Advanced
+## Advanced coding configuration
 
 You can provide custom coding configuration in order to encode long text by reducing number of characters
 

RoundCode.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name             = 'RoundCode'
-  s.version          = '1.1.0'
+  s.version          = '1.3.0'
   s.summary          = 'Facebook messenger style custom barcode.'
   s.description      = <<-DESC
                      Encode and decode data into custom stylish barcode.

Sources/Internal/RCConstants.swift

@@ -28,5 +28,6 @@ struct RCConstants {
   static let dotSizeScale: CGFloat = 0.08
   static let dotPatterns: [CGFloat] = [6, 4, 2]
   static let dotPointRange = (Float(1.3)...Float(2.5))
-  static let pixelThreshold = 180
+  static let lightBackgroundRange = UInt8(0)...UInt8(180)
+  static let darkBackgroundRange = UInt8(100)...UInt8(255)
 }

Sources/Internal/RCImageDecoder.swift

@@ -27,37 +27,18 @@ struct RCImageDecoder {
   internal let configuration: RCCoderConfiguration
   internal var size = 720
   internal var bytesPerRow = 720
-  internal var padding = 0
-  private var sectionSize: Int {
-    self.size / 5
-  }
+  internal var pixelThreshold = RCConstants.lightBackgroundRange
 }
 
 extension RCImageDecoder {
   func process(pointer: UnsafeMutablePointer<UInt8>) throws -> [RCBit] {
     let bufferData = UnsafeMutableBufferPointer<UInt8>(start: pointer, count: size * bytesPerRow)
     let data = PixelContainer(rows: bytesPerRow, items: bufferData)
-    var points = [CGPoint]()
-    for side in Side.allCases {
-      switch side {
-        case .left:
-          let point = try scanControlPoint(for: data, region: (padding, (size - sectionSize) / 2), side: side)
-          points.append(point)
-        case .top:
-          let point = try scanControlPoint(for: data, region: ((size - sectionSize) / 2, padding), side: side)
-          points.append(point)
-        case .right:
-          let point = try scanControlPoint(for: data, region: (size - sectionSize - padding, (size - sectionSize) / 2), side: side)
-          points.append(point)
-        case .bottom:
-          let point = try scanControlPoint(for: data, region: ((size - sectionSize) / 2, size - sectionSize - padding), side: side)
-          points.append(point)
-      }
-    }
+    let points = try scanControlPoints(for: data)
     let transform = calculateTransform(from: points)
     let mapper = RCPointMapper(transform: transform, size: size)
     let locations = mapper.map(points: calculateBitLocations())
-    let bits = locations.map { data[Int($0.x), Int($0.y)] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one }
+    let bits = locations.map { pixelThreshold.contains(data[Int($0.x), Int($0.y)]) ? RCBit.one : RCBit.zero }
     return bits
   }
   
@@ -72,47 +53,66 @@ extension RCImageDecoder {
 }
 
 extension RCImageDecoder {
-  private func scanControlPoint(for data: PixelContainer, region: (x: Int, y: Int), side: Side) throws -> CGPoint {
-    
-    func scan(region: (x: Int, y: Int, size: Int), data: PixelContainer, coordinate: (Int) -> (x: Int, y: Int), comparison: (PixelPattern, (x: Int, y: Int)) -> Bool) -> [PixelPattern] {
-      var lastPattern = PixelPattern(bit: data[region.x, region.y] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one, x: region.x, y: region.y, count: 0)
-      var pixelPatterns = [lastPattern]
-      var count = 0
-      let maxSize = region.size * region.size
-      while count < maxSize {
-        let coordinate = coordinate(count)
-        let bit = data[coordinate.x, coordinate.y] > RCConstants.pixelThreshold ? RCBit.zero : RCBit.one
-        if comparison(lastPattern, coordinate), lastPattern.bit == bit {
-          lastPattern.count += 1
-          pixelPatterns[pixelPatterns.count - 1] = lastPattern
-        } else {
-          lastPattern = PixelPattern(bit: bit, x: coordinate.x, y: coordinate.y, count: 1)
-          pixelPatterns.append(lastPattern)
-        }
-        count += 1
+  private func scanControlPoints(for data: PixelContainer) throws -> [CGPoint] {
+    var horizontalPatterns = [PixelPattern]()
+    var verticalPatterns = [PixelPattern]()
+    var points = [CGPoint]()
+    for side in Side.allCases {
+      switch side {
+        case .left:
+          horizontalPatterns = scanPixelPattern(for: .horizontal, data: data)
+          points.append(try controlPoint(for: horizontalPatterns, side: side))
+        case .right:
+          points.append(try controlPoint(for: horizontalPatterns, side: side))
+        case .top:
+          verticalPatterns = scanPixelPattern(for: .vertical, data: data)
+          points.append(try controlPoint(for: verticalPatterns, side: side))
+        case .bottom:
+          points.append(try controlPoint(for: verticalPatterns, side: side))
       }
-      return pixelPatterns
     }
-    
-    let pixelPatterns: [PixelPattern]
-    switch side {
-      case .left, .right:
-        pixelPatterns = scan(region: (region.x, region.y, sectionSize), data: data, coordinate: { count in
-          let x = count % sectionSize + region.x
-          let y = count / sectionSize + region.y
-          return (x, y)
-        }, comparison: { (pattern, coordinate) in
-          return pattern.y == coordinate.y
-        })
-      case .top, .bottom:
-        pixelPatterns = scan(region: (region.x, region.y, sectionSize), data: data, coordinate: { count in
-          let x = count / sectionSize + region.x
-          let y = count % sectionSize + region.y
-          return (x, y)
-        }, comparison: { (pattern, coordinate) in
-          return pattern.x == coordinate.x
-        })
+    return points
+  }
+
+  private func scanPixelPattern(for mode: ScanMode, data: PixelContainer) -> [PixelPattern] {
+    var lastPattern = PixelPattern(bit: pixelThreshold.contains((data[0, 0])) ? RCBit.one : RCBit.zero, x: 0, y: 0, count: 0)
+    var pixelPatterns = [lastPattern]
+    var count = 0
+    let maxSize = size * size
+    switch mode {
+      case .horizontal:
+        while count < maxSize {
+          let x = count % size
+          let y = count / size
+          let bit = pixelThreshold.contains(data[x, y]) ? RCBit.one : RCBit.zero
+          if lastPattern.y == y, lastPattern.bit == bit {
+            lastPattern.count += 1
+            pixelPatterns[pixelPatterns.count - 1] = lastPattern
+          } else {
+            lastPattern = PixelPattern(bit: bit, x: x, y: y, count: 1)
+            pixelPatterns.append(lastPattern)
+          }
+          count += 1
+      }
+      case .vertical:
+        while count < maxSize {
+          let x = count / size
+          let y = count % size
+          let bit = pixelThreshold.contains(data[x, y]) ? RCBit.one : RCBit.zero
+          if lastPattern.x == x, lastPattern.bit == bit {
+            lastPattern.count += 1
+            pixelPatterns[pixelPatterns.count - 1] = lastPattern
+          } else {
+            lastPattern = PixelPattern(bit: bit, x: x, y: y, count: 1)
+            pixelPatterns.append(lastPattern)
+          }
+          count += 1
+      }
     }
+    return pixelPatterns
+  }
+  
+  private func controlPoint(for pixelPatterns: [PixelPattern], side: Side) throws -> CGPoint {
     let controlPoints = try pixelPatterns.withUnsafeBufferPointer { (pixelPatternsBuffer) -> [CGPoint] in
       var points = [CGPoint]()
       guard pixelPatternsBuffer.count >= 5 else { throw RCError.decoding }
@@ -164,7 +164,7 @@ extension RCImageDecoder {
       }
     }.first!
   }
-  
+    
   private func calculateTransform(from points: [CGPoint]) -> CATransform3D {
     let perspective = RCTransformation(points)
     let middleRect = CGRect(origin: .zero, size: CGSize(width: CGFloat(size), height: CGFloat(size)))
@@ -215,6 +215,11 @@ extension RCImageDecoder {
     case right
   }
   
+  enum ScanMode {
+    case horizontal
+    case vertical
+  }
+  
   final class PixelContainer {
     let rows: Int
     var columns: Int { data.count / rows }

Sources/Public/RCCameraViewController.swift

@@ -23,7 +23,7 @@
 import UIKit
 import AVFoundation
 
-public final class RCCameraViewController: UIViewController, UIImagePickerControllerDelegate {
+public final class RCCameraViewController: UIViewController {
   
   //MARK: Public properties
   public weak var delegate: RCCameraViewControllerDelegate?
@@ -113,7 +113,6 @@ public extension RCCameraViewController {
     super.viewDidLayoutSubviews()
     configureMaskLayer()
     videoPreviewLayer?.frame = view.bounds
-    calculateScanArea()
   }
 }
 
@@ -157,12 +156,11 @@ extension RCCameraViewController {
     guard let captureDevice = AVCaptureDevice.default(for: .video) else { return }
     do {
       captureSession.sessionPreset = .hd1280x720
-      calculateScanArea()
       let input = try AVCaptureDeviceInput(device: captureDevice)
       input.device.activeVideoMaxFrameDuration = CMTimeMake(value: 1, timescale: 30)
       captureSession.addInput(input)
       let videoOutput = AVCaptureVideoDataOutput()
-      videoOutput.setSampleBufferDelegate(self, queue: .main)
+      videoOutput.setSampleBufferDelegate(self, queue: DispatchQueue.global(qos: .userInteractive))
       videoOutput.videoSettings = [kCVPixelBufferPixelFormatTypeKey as String: NSNumber(value: kCVPixelFormatType_420YpCbCr8BiPlanarFullRange)]
       captureSession.addOutput(videoOutput)
     } catch {
@@ -170,12 +168,6 @@ extension RCCameraViewController {
     }
   }
   
-  private func calculateScanArea() {
-    let actualWidth = view.frame.height / 16 * 9
-    let sideArea = (actualWidth - view.frame.width * 0.9) / 2
-    coder.imageDecoder.padding = Int(sideArea / actualWidth * 720)
-  }
-  
   private func configureVideoPreview(orientation: AVCaptureVideoOrientation = .portrait) {
     videoPreviewLayer?.removeFromSuperlayer()
     videoPreviewLayer = AVCaptureVideoPreviewLayer(session: captureSession)
@@ -205,8 +197,10 @@ extension RCCameraViewController: AVCaptureVideoDataOutputSampleBufferDelegate {
     coder.imageDecoder.bytesPerRow = bytesPerRow
     if let message = try? coder.decode(buffer: lumaCopy.assumingMemoryBound(to: UInt8.self)) {
       captureSession.stopRunning()
-      delegate?.cameraViewController(didFinishScanning: message)
-      dismiss(animated: true)
+      DispatchQueue.main.async {[weak self] in
+        self?.delegate?.cameraViewController(didFinishScanning: message)
+        self?.dismiss(animated: true)
+      }
     }
     lumaCopy.deallocate()
     CVPixelBufferUnlockBaseAddress(pixelBuffer, .readOnly)

Sources/Public/RCCoder.swift

@@ -25,6 +25,11 @@ import UIKit
 public final class RCCoder {
   
   public let configuration: RCCoderConfiguration
+  public var scanningMode = ScanningMode.lightBackground {
+    didSet {
+      imageDecoder.pixelThreshold = scanningMode == .lightBackground ? RCConstants.lightBackgroundRange : RCConstants.darkBackgroundRange
+    }
+  }
   internal lazy var imageDecoder = RCImageDecoder(configuration: self.configuration)
   internal lazy var imageEncoder = RCImageEncoder(configuration: self.configuration)
   internal lazy var bitCoder = RCBitCoder(configuration: self.configuration)
@@ -44,7 +49,6 @@ public extension RCCoder {
   func decode(_ image: UIImage) throws -> String {
     guard image.size.width == image.size.height else { throw RCError.wrongImageSize }
     imageDecoder.size = image.cgImage!.height
-    imageDecoder.padding = 0
     imageDecoder.bytesPerRow = image.cgImage!.height
     let bits = try imageDecoder.decode(image)
     let message = try bitCoder.decode(bits)
@@ -56,6 +60,13 @@ public extension RCCoder {
   }
 }
 
+public extension RCCoder {
+  enum ScanningMode {
+    case lightBackground
+    case darkBackground
+  }
+}
+
 extension RCCoder {
   
   func decode(buffer: UnsafeMutablePointer<UInt8>) throws -> String {
@@ -64,3 +75,4 @@ extension RCCoder {
     return message
   }
 }
+