ashatora/openlayers
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Making extent optional for projections

Browse Source 
The projection validity extent is used to generate a sensible
set of default resolutions and a sensible default tile grid.
By making it optional, we can still generate defaults - with
zoom levels that are similar to the default web mercator zoom
levels (based on fitting the world on a single tile, even if the
projection is not available for the whole world).
This commit is contained in:
ahocevar
2013-06-17 15:24:37 +02:00
parent d552d27a35
commit 37b369e0d7
4 changed files with 44 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/ol/tilegrid/tilegrid.js
+9 -6
View File
@@ -4,6 +4,7 @@ goog.require('goog.array');
goog.require('goog.asserts');
goog.require('ol.Coordinate');
goog.require('ol.Projection');
goog.require('ol.ProjectionUnits');
goog.require('ol.Size');
goog.require('ol.TileCoord');
goog.require('ol.TileRange');
@@ -410,21 +411,23 @@ ol.tilegrid.getForProjection = function(projection) {
ol.tilegrid.createForProjection =
function(projection, opt_maxZoom, opt_tileSize) {
var projectionExtent = projection.getExtent();
var size = Math.max(
projectionExtent[1] - projectionExtent[0],
projectionExtent[3] - projectionExtent[2]);
var size = goog.isNull(projectionExtent) ?
360 * ol.METERS_PER_UNIT[ol.ProjectionUnits.DEGREES] /
ol.METERS_PER_UNIT[projection.getUnits()] :
Math.max(projectionExtent[1] - projectionExtent[0],
projectionExtent[3] - projectionExtent[2]);
var maxZoom = goog.isDef(opt_maxZoom) ?
opt_maxZoom : ol.DEFAULT_MAX_ZOOM;
var tileSize = goog.isDef(opt_tileSize) ?
opt_tileSize : [ol.DEFAULT_TILE_SIZE, ol.DEFAULT_TILE_SIZE];
var resolutions = new Array(maxZoom + 1);
goog.asserts.assert(tileSize[0] == tileSize[1]);
size = size / tileSize[0];
size = size / Math.max(tileSize[0], tileSize[1]);
for (var z = 0, zz = resolutions.length; z < zz; ++z) {
resolutions[z] = size / Math.pow(2, z);
}
return new ol.tilegrid.TileGrid({
origin: ol.extent.getBottomLeft(projectionExtent),
origin: goog.isNull(projectionExtent) ? [0, 0] :
ol.extent.getBottomLeft(projectionExtent),
resolutions: resolutions,
tileSize: tileSize
});