Is a point inside a wedge?

// wedge objects: {cx:,cy:,radius:,startAngle:,endAngle:}
// var wedge={
//     cx:150, cy:150,  // centerpoint
//     radius:100,
//     startAngle:0, endAngle:Math.PI
// }
// Return true if the x,y point is inside the closed wedge

function isPointInWedge(x,y,wedge){
    var PI2=Math.PI*2;    
    var dx=x-wedge.cx;
    var dy=y-wedge.cy;
    var rr=wedge.radius*wedge.radius;
    if(dx*dx+dy*dy>rr){return(false);}
    var angle=(Math.atan2(dy,dx)+PI2)%PI2;
    return(angle>=wedge.startAngle && angle<=wedge.endAngle);
}