Rotation in flash causing image borders to look "pixely", how to fix?

Question

I have a bitmap loaded in flash, for a 2D game. The bitmap represents a character and is rotating when the user uses the A (left) or D (right) keys. The problem I have is that the border of the image becomes ugly while rotating, you can see "pixels" (you can always see pixels, but I hope you understand what I mean).

How can I fix this in actionscript 3, maybe change the rotation algorithm or "fix" the image after rotation? Or should I save/render the image differently in eg. Photoshop before using it with Flash?

Update: note that the background of the game is constantly changing.

Thanks in advance.

Answer 1

You could try a simple antialias along the edges by summing the pixel that is there and the pixel you will be overlaying. You could take a look at Wu antialiasing for an example you could use as a start point.

Answer 2

If the image is an external load (Loader class), then you can write:

Bitmap(myLoader.content).smoothing=true;

If it's internal (its in the library) you need to right click the library bitmap > properties and enable "Smoothing". Plus, if you are instantiating it as a BitmapData, then you need to do this:

var bmp:BitmapData=new LibraryBitmap(0,0);
var bitmap:Bitmap=new Bitmap(bmp,"auto",true); //the third argument is smoothing

Cheers...

Answer 3

use the flash.display.Bitmap::smoothing property ... the langref specifies, it smooth's when scaling, but it works for rotation as well ...

Answer 4

A quick note: Bitmap rotation is slow, so while loading the game, it might be a good idea to take characters that are often rotating, or are common, rotate them to every 1 degree that is possible in the game, use BitmapData.draw, and push it onto an Array (or a Vector in FP10, if possible), and then use those Bitmaps.

YAY, run-on sentences!

Happy Coding! :-)