Drawing a DisplayObject to a BitmapData

bmdFromDo.as

/**
 * Create a BitmapData image of a DisplayObject.
 * This will draw the entire DisplayObject onto a BitmapData, even if
 * the DisplayObject's registration point isn't the top-left extent of
 * the DisplayObject.
 * @param do The DisplayObject to create a BitmapData from.
 * @return  A BitmapData with the DisplayObject drawn onto it.
 */
public function bmdFromDo(do:DisplayObject):BitmapData
{
  // Save the bounds of the DisplayObject in case its registration point isn't the top-left extent.
  var doBounds:Rectangle = do.getBounds(do);
  
  // Create a new BitmapData rounding to the nearest unit that will contain the DisplayObject.
  var bmd:BitmapData = new BitmapData(uint(doBounds.width + 0.5), uint(doBounds.height + 0.5), true, 0);
  
  // Create a Matrix to transform the DisplayObject to the BitmapData in case its registration point isn't the top-left extent.
  var doMatrix:Matrix = new Matrix(1, 0, 0, 1, -doBounds.x, -doBounds.y);
  
  // Draw the DisplayObject onto the BitmapData using the transform matrix.
  bmd.draw(do, doMatrix);
  
  // Return the freshly-minted BitmapData.
  return bmd;
}