meshviewer/lib/utils/math.js

32 lines
779 B
JavaScript

define(function () {
var self = {};
self.distance = function distance(a, b) {
return (a.x - b.x) * (a.x - b.x) + (a.y - b.y) * (a.y - b.y);
};
self.distancePoint = function distancePoint(a, b) {
return Math.sqrt(self.distance(a, b));
};
self.distanceLink = function distanceLink(p, a, b) {
/* http://stackoverflow.com/questions/849211 */
var l2 = self.distance(a, b);
if (l2 === 0) {
return self.distance(p, a);
}
var t = ((p.x - a.x) * (b.x - a.x) + (p.y - a.y) * (b.y - a.y)) / l2;
if (t < 0) {
return self.distance(p, a);
} else if (t > 1) {
return self.distance(p, b);
}
return self.distancePoint(p, {
x: a.x + t * (b.x - a.x),
y: a.y + t * (b.y - a.y)
});
};
return self;
});