Reflection
What's wrong? : When ray starts from the inside of circle and near the edge, it'll be vanished without any ray out of the circle.
/**
* Copyright phi16 ( http://wonderfl.net/user/phi16 )
* MIT License ( http://www.opensource.org/licenses/mit-license.php )
* Downloaded from: http://wonderfl.net/c/9PU5
*/
package {
import flash.display.Sprite;
import flash.events.Event;
public class Fresnel extends Sprite {
public var bg:Sprite=new Sprite();
public var spr:Sprite=new Sprite();
public var IoR:Number=1.5;
public function Fresnel() {
addChild(bg);
addChild(spr);
bg.graphics.beginFill(0);
bg.graphics.drawRect(0,0,465,465);
bg.graphics.endFill();
bg.graphics.lineStyle(2,0xffffff);
bg.graphics.drawCircle(465/2.0,465/2.0,100);
spr.x=465/2.0;
spr.y=465/2.0;
addEventListener(Event.ENTER_FRAME,step);
}
public function step(e:Event):void{
spr.graphics.clear();
rayTrace(mouseX-465/2.0,mouseY-465/2.0,0,-1,1);
}
public function rayTrace(a:Number,b:Number,c:Number,d:Number,alpha:Number):void{
if(alpha<0.01)return;
var lei:Number=Math.sqrt(c*c+d*d);
c/=lei,d/=lei;
a+=0.1*c;
b+=0.1*d;
spr.graphics.lineStyle(4,0xffffff,alpha);
spr.graphics.moveTo(a,b);
var f:Boolean=false;
var D:Number,t:Number,p:Number,q:Number,le:Number,nx:Number,ny:Number,dp:Number,rx:Number,ry:Number,k:Number,f0:Number,fth:Number;
D=-a*a*d*d+2*a*b*c*d-b*b*c*c+10000;
if(a*a+b*b<10000){
if(D>0){
t=Math.sqrt(D)-a*c-b*d;
if(t>0){
p=a+c*t,q=b+d*t;
spr.graphics.lineTo(p,q);
le=Math.sqrt(p*p+q*q);
nx=-p/le,ny=-q/le;
dp=c*nx+d*ny;
rx=c-2*dp*nx,ry=d-2*dp*ny;
f0=Math.pow((IoR-1)/(IoR+1),2);
fth=f0+(1-f0)*Math.pow((1+dp),5);
rayTrace(p,q,rx,ry,alpha*fth);
k=1.0-IoR*IoR*(1.0-dp*dp);
if(k>0){
rx=IoR*c-(IoR*dp+Math.sqrt(k))*nx;
ry=IoR*d-(IoR*dp+Math.sqrt(k))*ny;
rayTrace(p,q,rx,ry,alpha*(1-fth));
}
f=true;
}
}
}else{
if(D>0){
t=-Math.sqrt(D)-a*c-b*d;
if(t>0){
p=a+c*t,q=b+d*t;
spr.graphics.lineTo(p,q);
le=Math.sqrt(p*p+q*q);
nx=p/le,ny=q/le;
dp=c*nx+d*ny;
rx=c-2*dp*nx,ry=d-2*dp*ny;
f0=Math.pow((1/IoR-1)/(1/IoR+1),2);
fth=f0+(1-f0)*Math.pow((1+dp),5);
rayTrace(p,q,rx,ry,alpha*fth);
k=1.0-1/(IoR*IoR)*(1.0-dp*dp);
if(k>0){
rx=1/IoR*c-(1/IoR*dp+Math.sqrt(k))*nx;
ry=1/IoR*d-(1/IoR*dp+Math.sqrt(k))*ny;
rayTrace(p,q,rx,ry,alpha*(1-fth));
}
f=true;
}
}
if(!f){
spr.graphics.lineTo(a+c*1000,b+d*1000);
}
}
}
}
}