Posts Tagged ‘png’

  • Save MovieClip as PNG Example

    A couple of guys on Twitter asked me if I would write-up how I generate PNG files from MovieClips in my SWF, at run-time. So I put this example together and am sharing it here.

    We use this technique in our virtual world WebbliWorld to save a PNG version of the users avatars after they have customised them. But there are all kinds of other reasons you may need this. My example includes two methods: Saving the PNG locally using the local file system, and Saving the PNG to a web server using AMFPHP.

    This technique requires Flash Player 10 and the Adobe AS3 Core Lib.

    Here’s a very simple example (included in the zip download below):

    Essentially it all boils down to this:

    1) When you are ready to save your image, create a Bitmap version of your MovieClip.

    [as]
    private function getMovieClipAsBitmap():Bitmap
    {
    var bounds:Rectangle = theMovieClip.getBounds(theMovieClip);

    //    The * 2 is because we’re scaling the clip up by a factor of two, to result in a larger PNG
    //    If you don’t need this, remove it and comment out the m.scale call below
    var theBitmap:Bitmap = new Bitmap(new BitmapData(bounds.width * 2, bounds.height * 2, true, 0x0));

    var m:Matrix = new Matrix(1, 0, 0, 1, -bounds.x, -bounds.y);

    //    Simply scale the matrix to make a bigger PNG. Here we are doubling it. Comment this out if you don’t need it.
    m.scale(2, 2);

    //    Need to crop the PNG to a given size? Pass it a Rectangle as the 5th parameter to draw()
    //var r:Rectangle = new Rectangle(0, 0, 50, 40);

    theBitmap.bitmapData.draw(theMovieClip, m, null, null, null, true);

    return theBitmap;
    }
    [/as]

    2) Convert this Bitmap to a ByteArray.

    [as]
    private function getMovieClipAsByteArrayPNG():ByteArray
    {
    var data:Bitmap = getMovieClipAsBitmap();

    var ba:ByteArray = PNGEncoder.encode(data.bitmapData);

    return ba;
    }
    [/as]

    3) Send this ByteArray to either the local filesystem, or AMFPHP.

    [as]
    //    Uses FileReference to save the PNG locally to the hard drive (see “saveToServer” for an alternative)
    private function saveLocalPNG(event:MouseEvent):void
    {
    var ba:ByteArray = getMovieClipAsByteArrayPNG();

    file.save(ba, “BirdyNamNam.png”);
    }
    [/as]

    Complete source code is included in the zip file including an AMFPHP PHP script for saving on a web server.

    Hope someone finds this useful.

    Download the Soure Code zip.