Files
openlayers/src/ol/geom/base.js
2013-08-30 13:30:25 -06:00

38 lines
1.1 KiB
JavaScript

goog.provide('ol.geom.VertexArray');
goog.require('ol.coordinate');
/**
* @typedef {Array.<ol.geom.Vertex>}
*/
ol.geom.VertexArray;
/**
* Calculate the squared distance from a point to a line segment.
*
* @param {ol.Coordinate} coordinate Coordinate of the point.
* @param {Array.<ol.Coordinate>} segment Line segment (2 coordinates).
* @return {number} Squared distance from the point to the line segment.
*/
ol.geom.squaredDistanceToSegment = function(coordinate, segment) {
// http://de.softuses.com/103478, Kommentar #1
var v = segment[0];
var w = segment[1];
var l2 = ol.coordinate.squaredDistance(v, w);
if (l2 === 0) {
return ol.coordinate.squaredDistance(coordinate, v);
}
var t = ((coordinate[0] - v[0]) * (w[0] - v[0]) +
(coordinate[1] - v[1]) * (w[1] - v[1])) / l2;
if (t < 0) {
return ol.coordinate.squaredDistance(coordinate, v);
}
if (t > 1) {
return ol.coordinate.squaredDistance(coordinate, w);
}
return ol.coordinate.squaredDistance(coordinate,
[v[0] + t * (w[0] - v[0]), v[1] + t * (w[1] - v[1])]);
};