First step : build your MovieClip with this frame order
Then Build and link a class for your MovieClip
package
{
import flash.display.MovieClip;
public class Tank extends MovieClip
{
private const SLICE:Number = 4 / Math.PI;
public function Tank()
{
this.stop();
}
public function set angle(value:Number):void
{
this.gotoAndStop( Math.round(value * SLICE) + 5 ); // calc the frame
}
}
}
Finally when you need to calculate the frame to render ; call your public method that convert an angle to a frame index.
_tank.angle = Math.atan2( mouseY - _tank.y, mouseX - _tank.x );
Demo
[swfobj src=”https://www.yopsolo.fr/wp/wp-content/uploads/2013/07/Dir8Animation.swf” width=”640″ height=”480″]
Download 
This nice tank is an Harkonen heavy tank from the game Dune 2