macruby video Santa-fy (with support for multiple Santas)

video_santafy.rb

framework 'Cocoa'
framework 'avfoundation'

class Santa
  t_url = NSURL.URLWithString("http://dl.dropbox.com/u/349788/mustache.png")
  t_source = CGImageSourceCreateWithURL t_url, nil
  @@tache = CGImageSourceCreateImageAtIndex t_source, 0, nil

  g_url = NSURL.URLWithString("http://dl.dropbox.com/u/349788/glasses.png")
  g_source = CGImageSourceCreateWithURL g_url, nil
  @@glasses = CGImageSourceCreateImageAtIndex g_source, 0, nil

  h_url = NSURL.URLWithString("http://dl.dropbox.com/u/349788/hat.png")
  h_source = CGImageSourceCreateWithURL h_url, nil
  @@hat = CGImageSourceCreateImageAtIndex h_source, 0, nil

  def initialize(layer)
    @bounds = CGRectZero 
    Dispatch::Queue.main.async do
      @face_layer = layer
      add_feature_layer(:@tache, @@tache)
      add_feature_layer(:@glasses, @@glasses)
      add_feature_layer(:@hat, @@hat)
    end
  end

  def add_feature_layer(instance_var_name, image)
    layer = instance_variable_set instance_var_name, CALayer.layer
    layer.contents = image
    layer.contentsGravity = KCAGravityResize
    @face_layer.addSublayer layer
  end
  
  def feature_intersection_size(feature)
    r = CGRectIntersection(feature.bounds, @bounds)
    r.size.width * r.size.height
  end
  
  def hide_features
    Dispatch::Queue.main.async do
      [@tache, @hat, @glasses].each { |e| e.opacity = 0 }
    end
  end

  def rearrange_features(feature)
    Dispatch::Queue.main.async do
      @bounds = feature.bounds
      if feature.hasRightEyePosition && feature.hasLeftEyePosition && feature.hasMouthPosition
        w = feature.bounds.size.width
        h = feature.bounds.size.height/5

        @tache.opacity = 0.9
        @tache.bounds = [0, 0, w, h]
        @tache.position = [(feature.mouthPosition.x + (feature.leftEyePosition.x + feature.rightEyePosition.x)/2)/2, feature.mouthPosition.y+ h/2]
        rotation = Math.atan2(feature.rightEyePosition.y-feature.leftEyePosition.y,feature.rightEyePosition.x-feature.leftEyePosition.x)
        @tache.setValue rotation, forKeyPath: "transform.rotation"

        w = feature.bounds.size.width
        h = feature.bounds.size.height/2.5

        @glasses.opacity = 1.0
        @glasses.bounds = [0, 0, w, h]
        @glasses.position = [(feature.leftEyePosition.x+feature.rightEyePosition.x)/2, (feature.rightEyePosition.y + feature.leftEyePosition.y)/2]
        rotation = Math.atan2(feature.rightEyePosition.y-feature.leftEyePosition.y,feature.rightEyePosition.x-feature.leftEyePosition.x)
        @glasses.setValue rotation, forKeyPath: "transform.rotation"

        w = feature.bounds.size.width*5/4
        h = feature.bounds.size.height*5/4

        @hat.opacity = 1.0
        @hat.bounds = [0, 0, w, h]
        @hat.position = [(feature.rightEyePosition.x + feature.leftEyePosition.x + feature.mouthPosition.x)/3, (feature.leftEyePosition.y+feature.rightEyePosition.y)/2- h/7 +h/2]
        rotation = 25*Math::PI/180+Math.atan2(feature.rightEyePosition.y-feature.leftEyePosition.y,feature.rightEyePosition.x-feature.leftEyePosition.x)
        @hat.setValue rotation, forKeyPath: "transform.rotation"
      end
    end
  end

end

class FaceDetectionDelegate
  attr_accessor :window

  def applicationDidFinishLaunching(aNotification)
    
    @santas_array = []
    @detector = CIDetector.detectorOfType "CIDetectorTypeFace", context:nil, options:{CIDetectorAccuracy: CIDetectorAccuracyLow}
    
    session = AVCaptureSession.new
    device = AVCaptureDevice.defaultDeviceWithMediaType AVMediaTypeVideo

    case device.supportsAVCaptureSessionPreset AVCaptureSessionPreset1280x720
    when true
      session.sessionPreset = AVCaptureSessionPreset1280x720
      width = 1280
      height = 720
    else
      session.sessionPreset = AVCaptureSessionPreset640x480
      width = 640
      height = 480
    end

    input = AVCaptureDeviceInput.deviceInputWithDevice device, error:nil
    output = AVCaptureVideoDataOutput.new
    output.alwaysDiscardsLateVideoFrames = true

    queue = Dispatch::Queue.new('cameraQueue')
    output.setSampleBufferDelegate self, queue:queue.dispatch_object
    output.setVideoSettings KCVPixelBufferPixelFormatTypeKey => KCVPixelFormatType_32BGRA, KCVPixelBufferWidthKey => width, KCVPixelBufferHeightKey => height

    session.addInput input
    session.addOutput output

    @preview_layer = AVCaptureVideoPreviewLayer.layerWithSession session
    @preview_layer.frame = [0.0, 0.0, width, height]
    @preview_layer.videoGravity = AVLayerVideoGravityResizeAspectFill
    @preview_layer.affineTransform = CGAffineTransformMakeScale -1, 1

    session.startRunning

    window.setFrame [0.0, 0.0, width, height], display:true, animate:true
    window.center
    window.delegate = self

    window.contentView.wantsLayer = true
    window.contentView.layer.addSublayer @preview_layer

    window.orderFrontRegardless    
  end

  def add_face
    @santas_array << Santa.new(@preview_layer)
  end

  def captureOutput(captureOutput, didOutputSampleBuffer:sampleBuffer, fromConnection:connection)
    imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer)
    image = CIImage.imageWithCVImageBuffer(imageBuffer)

    features = @detector.featuresInImage(image)
    
    add_face while features.size > @santas_array.size
    
    # we need to match each new face from the feature_detector to the appropriate CALayers with Santa features
    # otherwise the santa features jump from one person to another - complete bedlam.
    santas = @santas_array.dup
    features.each do |feature|
      matched_face = santas.sort_by! {|s| s.feature_intersection_size(feature) }.pop
      matched_face.rearrange_features feature
    end
    santas.each { |e| e.hide_features } # any remaining santas have exited the frame and should be hidden.
    nil
  end

  def windowWillClose(sender); exit(1); end

end

# Create the Application
application = NSApplication.sharedApplication
NSApplication.sharedApplication.activationPolicy = NSApplicationActivationPolicyRegular
application.delegate = FaceDetectionDelegate.new
# create the Application Window
frame = [0.0, 0.0, 330, 250]
window = NSWindow.alloc.initWithContentRect frame,
styleMask: NSTitledWindowMask | NSClosableWindowMask,
backing: NSBackingStoreBuffered,
defer: false

application.delegate.window = window
window.orderOut(nil)
window.display
puts "Starting the app..."
application.run