Using iSight

This document illustrates how to use iSight on your Mac using CocoaSequenceGrabber, an easy-to-use Cocoa framework for grabbing a photo from an iSight.

Preparation

1. Install CocoaSequenceGrabber into /Library/Frameworks folder.
2. Create a new Xcode project using Cocoa-Ruby Game Application template (avaialble at Downloads page).
3. Add CocoaSequenceGrabber into "Frameworks -> Other Frameworks" group on the Xcode project.
4. Add a new file (say Photogenic.rb) using "Ruby Game file" template.

Get CocoaSequenceGrabber ready to use from MiniKidsGames

First of all, you need to make CocoaSequenceGrabber class from ruby world. To do this, you can add a code as shown below at the beginning of your game file.

NSBundle.bundleWithPath('/Library/Frameworks/CocoaSequenceGrabber.framework').load
module OSX
  ns_import :CSGCamera
  ns_import :CSGImage
end

Write classes

Now you're ready to take a snapshot and save it onto Desktop. Here's the code for doing this. The following code works on the Game Framework. You can copy a snapshot to the Desktop by pressing space.

class PhotogenicModel < NSObject
  def init()
   # initialization
   @size = NSSize.new(640, 480)
   @buffer = NSImage.alloc.initWithSize(@size)
   return self
  end

  def start()
    @refreshed = false
    @camera = CSGCamera.alloc.init
    @camera.setDelegate(self)
    @camera.startWithSize(@size);
    @image = nil
    @count = 0
  end

  def camera_didReceiveFrame(camera, frame)
    @image = frame
    @refreshed = true
  end

  def shoot()
    @image.TIFFRepresentation.writeToFile_atomically("/Users/tat/Desktop/Shot#{@count}.tiff", true)
    @count += 1
  end 
  
  def stop()
    @camera.stop if (@camera)
  end

  # Add some methods here
  attr_reader :image, :refreshed, :size
end

class PhotogenicPlayingState < State
  # define your timer IDs here
  MYGAME_TIMER = 1000

  def enter()
    super()
    @model.start()

    # Define context dependent event handlers
    # Each handlers are defined in a form of [EventType, Content, Proc object]
    # See KeyEvent.rb, MouseEvent.rb and TimerEvent.rb for event specific info
    # Other game's source code would also help you
    contexts = [[TimerEvent::Fired, MYGAME_TIMER, proc {|id| tick() }],
                [KeyEvent::NSKeyDown, KeyEvent::SPACE, proc {|event| @model.shoot(); true}]]
    contexts.each {|context| EventContext.addContext(*context) }
    @timer = TimerEvent.new(0.1, true, MYGAME_TIMER)
  end
 
  def tick()
    # do something when timer event occurs
    return true
  end
  
  def leave()
    @model.stop()
    super()
  end
  
  # add some event handlers or context handlers here
end

class PhotogenicView < View
  def setModel(model)
    @initialized = false
    @point = NSPoint.new(0,0)
    super(model)
  end   

 #
 # This method is called from MiniGamesView
 # 
 def drawRect()
   if (@initialized == false)
     NSColor.blackColor.set
     NSRectFill(@bounds)
     @initialized = true
   end
   
   if (@model.image)
      @point = Field.centerizedPoint(@model.image.size)
      @model.image.compositeToPoint_operation(@point, NSCompositeXOR)
   end
 end
 
  def getInvalidRects()
    if (@model.refreshed)
      return [NSRect.new(@point, @model.size)]
    else
      return super()
    end
  end
end

class Photogenic < Game
  def initialize()
    @bindings = [[PhotogenicPlayingState, PhotogenicModel, PhotogenicView]]
    @initialState = PhotogenicPlayingState
  end
  def self.title() "Photogenic" end
  def self.titleImage() nil end # return the name of an image here
  def self.getPreferenceItems()
    return [BoolPreference.new('Fullscreen', true),
            BoolPreference.new('OpaqueWindow', false),
            StringPreference.new('Font', 'Marker Felt'),
    ]
  end
end

Downloads

Will be added soon