docs: protected void onDrawFrame( SurfaceView view , Canvas canvas ) {
  
  		// Code below is usefull when debugging display issues
  //		Paint paintFill = new Paint();
  //		paintFill.setColor(Color.RED);
  //		paintFill.setStyle(Paint.Style.FILL);
  //		Paint paintBorder = new Paint();
  //		paintBorder.setColor(Color.BLUE);
  //		paintBorder.setStyle(Paint.Style.STROKE);
  //		paintBorder.setStrokeWidth(6*displayMetrics.density);
  //
  //		Rect r = new Rect(0,0,view.getWidth(),view.getHeight());
  //		canvas.drawRect(r,paintFill);
  //		canvas.drawRect(r,paintBorder);
  		switch( bitmapMode) {
  			case UNSAFE:
  				canvas.drawBitmap(this.bitmap, imageToView, null);
  				break;
  
  			case DOUBLE_BUFFER:
  				bitmapLock.lock();
  				try{
  					canvas.drawBitmap(this.bitmap, imageToView, null);
  				} finally {
  					bitmapLock.unlock();
  				}
  				break;
  		}
  	}