openlayers/src/ol/geom/flat/center.js

Build tools and sources for developing OpenLayers based mapping applications

goog.provide('ol.geom.flat.center');

goog.require('ol.extent');


/**
 * @param {Array.<number>} flatCoordinates Flat coordinates.
 * @param {number} offset Offset.
 * @param {Array.<Array.<number>>} endss Endss.
 * @param {number} stride Stride.
 * @return {Array.<number>} Flat centers.
 */
ol.geom.flat.center.linearRingss = function(flatCoordinates, offset, endss, stride) {
  var flatCenters = [];
  var i, ii;
  var extent = ol.extent.createEmpty();
  for (i = 0, ii = endss.length; i < ii; ++i) {
    var ends = endss[i];
    extent = ol.extent.createOrUpdateFromFlatCoordinates(
        flatCoordinates, offset, ends[0], stride);
    flatCenters.push((extent[0] + extent[2]) / 2, (extent[1] + extent[3]) / 2);
    offset = ends[ends.length - 1];
  }
  return flatCenters;
};