biohazard symbol

biohazard.js

//print biohazard symbol, at http://fab.cba.mit.edu/classes/S62.12/people/martinanderson.brandon/solver2.html

function makecircle(r){
  return function(x,y){
    return Math.pow(x,2) + Math.pow(y,2) < Math.pow(r,2);
  }
}

function translate(tx, ty, func){
  return function(x,y){
    var xprime = x-tx;
    var yprime = y-ty;

    return func(xprime,yprime);
  }
}

function rotate(theta, func){
  return function(x,y){
    var xprime = Math.cos(theta)*x-Math.sin(theta)*y;
    var yprime = Math.sin(theta)*x+Math.cos(theta)*y;

    return func(xprime,yprime);
  }
}

function union(funcs){
  var metaargs=arguments;
  return function(x,y) {
    var ret=false;
    for(var i=0; i<metaargs.length;i++){
      ret = ret || metaargs[i](x,y);
    }
    return ret;
  }
}

function cut( pos, neg ){
  return function(x,y){ return pos(x,y) && !neg(x,y); };
}

function triple( func ){
  return union(
           rotate( 0,
               func
           ),
           rotate( 2*(2*Math.PI)/3,
               func
           ),
           rotate( 1*(2*Math.PI)/3,
               func
           )
         );
}

function makering(inner, outer){
  return cut( 
             makecircle(outer), 
             makecircle(inner)
         );
}

function makerectangle(ll,bb,rr,tt){
  return function(x,y){
    return x>ll && x<rr && y>bb && y<tt;
  }
}

function nothing(){
  return function(x,y){return false};
}

var r=70;
var cutwidth=5;
var crescentid=0.8;
var highlight=0.92;

function crescent(){
  return cut(makecircle(r),
            translate(0,-r*0.21,
              makecircle(r*crescentid)
           )
         );
}

function solids(){
 return union( 
          triple( 
            translate( 0, -r, crescent() )
          ), 
          makering(r-15, r)
        );
}

function finishcuts(){
 return union( triple(
             union(
               translate(0,-r*1.21,
                 makering(r*crescentid*highlight, r*crescentid)
               ),
               rotate(2*Math.PI/6,
                 makerectangle(-cutwidth/2,0,cutwidth/2,50)
               )
             )
           ), makecircle(20))
}

function skew(tx, ty, func){
  return function(x,y){
    var xprime = x-(tx*y*y);
    var yprime = y-(ty*x*x);

    return func(xprime,yprime);
  }
}

function scale(sx, sy, func){
  return function(x,y){
    return func(x/sx, y/sy);
  }
}

emit( translate(250,250,
         scale(1.6,1.6,cut(
           solids(),
           finishcuts()
         ))
       ) );