flash on 2012-11-12

by mutantleg 12 Nov 2012

• Related works: 1
Embed

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

package {
    import flash.text.TextField;
    import flash.events.Event;
    import flash.display.Sprite;
    public class FlashTest extends Sprite {
        public function FlashTest() {
            // write as3 code here..
            
            deb = new TextField();
            addChild(deb);
            
            stage.addEventListener(Event.ENTER_FRAME, onEnter);
        }//ctor
        
        public var px:Number = 100;
        public var py:Number  = 100;
        
        public var deb:TextField;
        
        public function onEnter(e:Event):void
        {
            graphics.clear();
            graphics.lineStyle(2,0);
            
            var ax:Number = 200;
            var ay:Number = 200;
            var ar:Number = 64;
            
            graphics.drawCircle(ax, ay, ar);
            
            
     
   //  px = 200;
     //py = 200;       
           
            var mx:Number = 200;
            var my:Number = 200;
           
           mx = px;
           my = py;
            
           mx = mouseX;
           my = mouseY;
            
            var t:Number;
            var kx:Number;
            var ky:Number;
            
            graphics.moveTo(px,py);
            graphics.lineTo(mx,my);
            
            t  =0;
            t = lineCirc3(px,py,mx,my,ax,ay,ar);
            // if (t == 999) { t= 1;}
            
            deb.text = "t: " + t;
            
            if (t > 0 && t < 1)
            {
            kx = px + (mx - px) * t;
            ky = py + (my - py) * t;
            }
            else
            {
                kx = mx;
                ky = my;
                }
                
            graphics.drawCircle(kx,ky, 12);
            
            var dx:Number;
            var dy:Number;
            var mag:Number;
            
            dx = kx - ax;
            dy = ky - ay;
            
            mag = Math.sqrt(dx*dx+dy*dy);
            if (mag == 0) { mag = 0.00001;}
            dx /= mag;
            dy /= mag;
            
           // deb.text = "mag " + mag;
         
         if (mag <= (ar+8))
         {
           
            px = kx +((ar+8)-mag) * dx;
            py = ky+((ar+8)-mag) * dy;   
         }  
         else
         {
          px = kx;
          py = ky;   
             }
           
           //px += (mx-px)*0.1;
          // py += (my-py)*0.1;
            
            graphics.drawCircle(px,py, 4);
            
            
         }//onenter
         
          //based on
        //http://www.geometrictools.com/SamplePhysics/CollisionsMovingSphereTriangle/RTSphereTriangle.cpp
        
        public function lineCirc3(
        ax:Number, ay:Number, bx:Number, by:Number,
        cx:Number, cy:Number, rad:Number):Number
        {
            
            if (ax == bx && ay == by) { return 0; }
          
          var rsq:Number
          var vx:Number;
          var vy:Number;
          var mx:Number;
          var my:Number;
          var q2:Number;
          var q1:Number;
          var q0:Number;
          var disc:Number;
          
          rsq = rad * rad;
          
          mx = cx - ax;
          my = cy - ay;
          vx = ax - bx;
          vy = ay - by;
          
          q2 = (vx*vx +vy*vy);
          q1 = (vx*mx + vy*my);
          q0 = (mx*mx + my*my) - rsq;
          
          disc = q1*q1 - q0 * q2;
          
          if (disc < 0) { return 999; }
          
          var invq2:Number;
          var rootdisc:Number;
          var root0:Number;
          var root1:Number;
          
    //      deb.text = "v " + ax;
          
          invq2 = 1 / q2;
          rootdisc = Math.sqrt(disc);
          root0 = (-q1 - rootdisc) * invq2;
          root1 = (-q1 + rootdisc) * invq2;

          
          return root0;
        }//linecirc3
         
        
    }//classend
}