为什么这段代码导致无限循环？

Question

I cant for my life figure out why this doesn't work.

var refP = [];
var distance = function (p1, p2) {
    return dist(p1.x, p1.y, p2.x, p2.y);
}
while (refP.length < 24) {
    var pusher = {
        x: -1,
        y: -1,
        closestRefP: 9999999
    };
    pusher.x = (random(0, 400));
    pusher.y = (random(0, 400));
    for (var d = 0; d < refP.length; d++) {
        if (distance(pusher, refP[d]) < pusher.closestRefP) {
            pusher.closestRefP = distance(pusher, refP[d]);
        }
    }
    if (pusher.closestRefP > 2) {
        refP[refP.length] = pusher;
    }
}

It doesn't give me the loop when I remove the last if-statement and just unconditionally push pusher onto refP.

Thanks. And please let me know if I should clean up this code or maybe try to isolate the problem in less code.

Answer 1

Are you sure your random and dist functions works properly?

Replacing your distance function with:

var distance = function (point1, point2) {
  var xs = 0;
  var ys = 0;

  xs = point2.x - point1.x;
  xs = xs * xs;

  ys = point2.y - point1.y;
  ys = ys * ys;

  return Math.sqrt( xs + ys );
}

and your random(0, 400) calls with this:

pusher.x = Math.floor(Math.random() * 400);
pusher.y = Math.floor(Math.random() * 400);

Worked for me.