ActionScript 3 Draw a display object with any coordinates of registration point


    public function drawDisplayObjectUsingBounds(source:DisplayObject):BitmapData {
        var bitmapData:BitmapData;//declare a BitmapData
        var bounds:Rectangle = source.getBounds(source);//get the source object actual size
        //round bounds to integer pixel values (to aviod 1px stripes left off)
        bounds = new Rectangle(Math.floor(bounds.x), Math.floor(bounds.y), Math.ceil(bounds.width), Math.ceil(bounds.height));

        //to avoid Invalid BitmapData error which occures if width or height is 0
        //(ArgumentError: Error #2015)
        if((bounds.width>0) && (bounds.height>0)){
            //create a BitmapData
            bitmapData = new BitmapData(bounds.width, bounds.height, true, 0x00000000);                
            var matrix:Matrix = new Matrix();//create a transform matrix
            //translate if to fit the upper-left corner of the source
            matrix.translate(-bounds.x, -bounds.y);
            bitmapData.draw(source, matrix);//draw the source
            return bitmapData;//return the result (exit point)
        //if no result is created - return an empty BitmapData
        return new BitmapData(1, 1, true, 0x00000000);

A side note: For getBounds() to return valid values the object has to have stage access at least once, otherwise the values are bogus. A code can be added to ensure that passed source has stage, and if not, it can be added to stage then removed again.