distance-segment2 (v3)

Revision 3 of this benchmark created on November 14, 2013

Setup

var p1 = [{X:10,Y:20},{X:21,Y:15},{X:1,Y:-20}];
    var p2 = [{X:100,Y:200},{X:210,Y:150},{X:10,Y:-200}];
    var p3 = [{X:30,Y:11},{X:14,Y:-12},{X:0,Y:19}];
    var cnt=10;
    var min = -9999;
    var max =  9999;
    function rand () {
        return Math.random() * (max - min) + min;
    }
    for(var i=0;i<cnt;i++)
    {
      p1.push({X:rand(),Y:rand()});
      p2.push({X:rand(),Y:rand()});
      p3.push({X:rand(),Y:rand()});
    }
    
        function sqr(x) { return x * x }
    function dist2(v, w) { return sqr(v.X - w.X) + sqr(v.Y - w.Y) }
    function distToSegmentSquared(p, v, w) {
      var l2 = dist2(v, w);
      if (l2 == 0) return dist2(p, v);
      var t = ((p.X - v.X) * (w.X - v.X) + (p.Y - v.Y) * (w.Y - v.Y)) / l2;
      if (t < 0) return dist2(p, v);
      if (t > 1) return dist2(p, w);
      return dist2(p, { X: v.X + t * (w.X - v.X),
                        Y: v.Y + t * (w.Y - v.Y) });
    }
    
    // square distance from a point to a segment
    function getSqSegDist(p, p1, p2) {
    
        var x = p1.X,
            y = p1.Y,
            dx = p2.X - x,
            dy = p2.Y - y;
    
        if (dx !== 0 || dy !== 0) {
    
            var t = ((p.X - x) * dx + (p.Y - y) * dy) / (dx * dx + dy * dy);
    
            if (t > 1) {
                x = p2.X;
                y = p2.Y;
    
            } else if (t > 0) {
                x += dx * t;
                y += dy * t;
            }
        }
    
        dx = p.X - x;
        dy = p.Y - y;
    
        return dx * dx + dy * dy;
    }

Test runner

var d1;
for(var i = 0, ilen = p1.length; i<ilen;i++)
{
  d1=getSqSegDist(p1[i], p2[i], p3[i]);
}
 

var d2;
for(var i = 0, ilen = p1.length; i<ilen;i++)
{
  d2=distToSegmentSquared(p1[i], p2[i], p3[i]);
}

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.

• Revision 3: published on November 14, 2013