flash on 2016-3-20

/**
 * Copyright bradford.sedito ( http://wonderfl.net/user/bradford.sedito )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/yrZ8
 */




package {
    /* a tornado made of text
     */
    import flash.events.Event;
    import flash.geom.Vector3D;
    import flash.text.TextField;
    import flash.text.TextFormat;
    import flash.display.Sprite;
    import flash.text.TextField;

[SWF(backgroundColor="0x000000", width="800", height="600", frameRate="30")]

    public class Twister extends Sprite {

        private var tornadoRadius:Number = 250;
        private var tornadoHeight:Number = 1000;
        private var letters:String = "|";//"ABCDEFGHIJKLMNOPQRSTUVWXYZ"; 
        private var numFloaters:int = 300;
        private var floaters:Vector.<TextField> = new Vector.<TextField>(numFloaters);
        private var tf:TextFormat = new TextFormat("Arial", 24);
        private var ctr:Vector3D;

        public function Twister() {
            
            tf.color = 0x00FF00;

            for(var i:int = 0; i < numFloaters; ++i)
            {    
                ctr = new Vector3D(stage.stageWidth/2,800, 500);
                //create letter 
                var t:TextField = new TextField();
                var idx:int = Math.round(Math.random()*25);
                t.defaultTextFormat = tf;
                t.text = letters.charAt(idx);
                floaters[i] = t;
                //set positions
                t.x =  Math.random()*stage.stageWidth;
                t.y =  ctr.y - Math.random()*tornadoHeight;
                t.z =  Math.random()*1000;
                t.rotationX = Math.random()*360;
                t.rotationY = Math.random()*360;
                t.rotationZ = Math.random()*360;
                addChild(t);
                addEventListener(Event.ENTER_FRAME, onEnterFrame);
            }
        }
        private function onEnterFrame(event:Event):void {
            for(var f:int = 0; f < numFloaters; ++f)
            {
                var t:TextField = floaters[f];
                if(t.y < -150){
                    t.y = ctr.y;//respawn at the bottom
                    continue;
                }
                var xd:Number = t.x - ctr.x;
                var zd:Number = t.z - ctr.z;
                var angle:Number = Math.atan2(xd,zd);//radians
                var radius:Number = Math.sqrt(xd*xd + zd*zd);
                radius -= 5;
                angle+=0.05;
                //stabilize letter at a radius which increase as y decreases
                if(radius < tornadoRadius) {
                    t.y--;//updraft
                    radius = tornadoRadius*(tornadoHeight - t.y)/tornadoHeight;
                }

                //seen from above,
                //z is the new x, increasing rightwards
                //x is the new y, increasing downwards
                //get new z, x positions
                //and add back to ctr
                t.z = ctr.z + radius*Math.cos(angle);
                t.x = ctr.x + radius*Math.sin(angle);

            }
        }
    }
}















/*

package {
    import flash.display.Sprite;
    public class FlashTest extends Sprite {
        public function FlashTest() {
            // write as3 code here..
            
        }
    }
}

*/