flash on 2015-1-10

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

package {
    import flash.events.Event;
    import flash.display.Sprite;
    public class FlashTest extends Sprite {
        public function FlashTest() {
         
           vecPart = new Vector.<xPart>(0, false);
           var i:int; var a:xPart;
           for (i = 0; i < 4; i++)
           {
             a = new xPart(); vecPart.push(a);
             a.cx = cx + Math.cos(i*0.3)*32;
             a.cy = cy + Math.sin(i*0.3)*32;
           } 
            
           stage.addEventListener(Event.ENTER_FRAME, onEnter); 
        }//ctor
        
        public function isWall(ax:Number, ay:Number):Boolean
        {
           if (ax < 0) { return true; }
           if (ay < 0) { return true; }
           if (ax > 465) { return true; }
           if (ay > 465) { return true; }
           return false;
        }//iswall
        
        public var cx:Number = 230;
        public var cy:Number = 230;
        
        public var vecPart:Vector.<xPart>;
        
        public function onEnter(e:Event):void
        {
            graphics.clear();
            graphics.lineStyle(2, 0);
       
            var mx:Number; var my:Number;
            mx = stage.mouseX; my = stage.mouseY;
            
            cx = mx; cy = my;
            
            graphics.drawCircle(cx,cy, 32);
       
             var ang:Number; var d:Number;
            
            var i:int; var num:int; 
            var a:xPart; var b:xPart;
            num = vecPart.length;
            
               var t:Number;
               t = 0.2;
               
            for (i = 0; i < num; i++)
            {
               a = vecPart[i];
               if (i+1==num) { b=vecPart[0];} else { b = vecPart[i+1]; }
               ang = Math.atan2(b.cy-a.cy, b.cx-a.cx);
               d = getMag(a.cx-b.cx, a.cy-b.cy);
              // t = (30-d)*0.01;
              // if (t < -2) { t = -2; }
              // else if (t >2) { t =2;}
                a.vx += Math.cos(ang) *t;
                a.vy += Math.sin(ang) *t;
               graphics.moveTo(a.cx,a.cy);
               graphics.lineTo(b.cx,b.cy);
       
            }//nexti
            
            t=0.5;
            for (i = 0; i <num; i++)
            {
               a = vecPart[i];
               
               a.vy += 0.1;
            
            
               ang = Math.atan2(cy-a.cy, cx-a.cx);
               d = getMag(a.cx-cx, a.cy-cy);
               if (d > 80)
               {
                a.vx += Math.cos(ang) *t;
                a.vy += Math.sin(ang) *t;
               }else if (d < 70)
               {
                a.vx += Math.cos(ang) *-t;
                a.vy += Math.sin(ang) *-t;
             
                }
               
                a.vx *=0.95; a.vy *= 0.95;
                
                if (a.vx > 0 && isWall(a.cx+a.vx,a.cy)) {a.vx*=-0.5; }
                if (a.vx < 0 && isWall(a.cx+a.vx,a.cy)) {a.vx*=-0.5; }
                if (a.vy > 0 && isWall(a.cx,a.cy+a.vy)) {a.vy*=-0.5; }
                if (a.vy < 0 && isWall(a.cx,a.cy+a.vy)) {a.vy*=-0.5; }
                
                a.cx+=a.vx; a.cy+=a.vy;
            
                graphics.moveTo(a.cx,a.cy);
                graphics.lineTo(cx,cy);
            
               graphics.drawCircle(a.cx, a.cy, 4); 
                
            }//nexti
            
            
            graphics.beginFill(0xF33524,0.5);
            a = vecPart[0];   graphics.moveTo(a.cx,a.cy);
            for (i = 1; i < num; i++)
            { a = vecPart[i];   graphics.lineTo(a.cx,a.cy); }
            a = vecPart[0];   graphics.lineTo(a.cx,a.cy);
            graphics.endFill();
            
        }//onenter
        
        public function getMag(ax:Number, ay:Number):Number
        { return Math.sqrt(ax*ax+ay*ay); } 
        
    }//classend
}

internal class xPart
{
   public var cx:Number = 0;
   public var cy:Number = 0;
   public var vx:Number = 0;
   public var vy:Number = 0;
   
}//xpart