Files
openlayers/src/ol/tilegrid/xyztilegrid.js

59 lines
1.3 KiB
JavaScript

goog.provide('ol.tilegrid.XYZ');
goog.require('ol.Coordinate');
goog.require('ol.Size');
goog.require('ol.TileRange');
goog.require('ol.projection');
goog.require('ol.projection.EPSG3857');
goog.require('ol.tilegrid.TileGrid');
/**
* @constructor
* @extends {ol.tilegrid.TileGrid}
* @param {ol.tilegrid.XYZOptions} xyzOptions XYZ options.
*/
ol.tilegrid.XYZ = function(xyzOptions) {
var resolutions = new Array(xyzOptions.maxZoom + 1);
var z;
var size = 2 * ol.projection.EPSG3857.HALF_SIZE / ol.DEFAULT_TILE_SIZE;
for (z = 0; z <= xyzOptions.maxZoom; ++z) {
resolutions[z] = size / Math.pow(2, z);
}
goog.base(this, {
origin: new ol.Coordinate(-ol.projection.EPSG3857.HALF_SIZE,
ol.projection.EPSG3857.HALF_SIZE),
resolutions: resolutions,
tileSize: new ol.Size(ol.DEFAULT_TILE_SIZE, ol.DEFAULT_TILE_SIZE)
});
};
goog.inherits(ol.tilegrid.XYZ, ol.tilegrid.TileGrid);
/**
* @inheritDoc
*/
ol.tilegrid.XYZ.prototype.forEachTileCoordParentTileRange =
function(tileCoord, callback, opt_obj) {
var x = tileCoord.x;
var y = tileCoord.y;
var z = tileCoord.z;
var tileRange;
while (true) {
z -= 1;
if (z < 0) {
break;
}
x >>= 1;
y >>= 1;
tileRange = new ol.TileRange(x, y, x, y);
if (callback.call(opt_obj, z, tileRange)) {
break;
}
}
};