Name modules more like their provide

src/ol/tilegrid.js

@@ -0,0 +1,156 @@
+goog.provide('ol.tilegrid');
+
+goog.require('ol');
+goog.require('ol.size');
+goog.require('ol.extent');
+goog.require('ol.extent.Corner');
+goog.require('ol.obj');
+goog.require('ol.proj');
+goog.require('ol.proj.Units');
+goog.require('ol.tilegrid.TileGrid');
+
+
+/**
+ * @param {ol.proj.Projection} projection Projection.
+ * @return {!ol.tilegrid.TileGrid} Default tile grid for the passed projection.
+ */
+ol.tilegrid.getForProjection = function(projection) {
+  var tileGrid = projection.getDefaultTileGrid();
+  if (!tileGrid) {
+    tileGrid = ol.tilegrid.createForProjection(projection);
+    projection.setDefaultTileGrid(tileGrid);
+  }
+  return tileGrid;
+};
+
+
+/**
+ * @param {ol.tilegrid.TileGrid} tileGrid Tile grid.
+ * @param {ol.TileCoord} tileCoord Tile coordinate.
+ * @param {ol.proj.Projection} projection Projection.
+ * @return {ol.TileCoord} Tile coordinate.
+ */
+ol.tilegrid.wrapX = function(tileGrid, tileCoord, projection) {
+  var z = tileCoord[0];
+  var center = tileGrid.getTileCoordCenter(tileCoord);
+  var projectionExtent = ol.tilegrid.extentFromProjection(projection);
+  if (!ol.extent.containsCoordinate(projectionExtent, center)) {
+    var worldWidth = ol.extent.getWidth(projectionExtent);
+    var worldsAway = Math.ceil((projectionExtent[0] - center[0]) / worldWidth);
+    center[0] += worldWidth * worldsAway;
+    return tileGrid.getTileCoordForCoordAndZ(center, z);
+  } else {
+    return tileCoord;
+  }
+};
+
+
+/**
+ * @param {ol.Extent} extent Extent.
+ * @param {number=} opt_maxZoom Maximum zoom level (default is
+ *     ol.DEFAULT_MAX_ZOOM).
+ * @param {number|ol.Size=} opt_tileSize Tile size (default uses
+ *     ol.DEFAULT_TILE_SIZE).
+ * @param {ol.extent.Corner=} opt_corner Extent corner (default is
+ *     ol.extent.Corner.TOP_LEFT).
+ * @return {!ol.tilegrid.TileGrid} TileGrid instance.
+ */
+ol.tilegrid.createForExtent = function(extent, opt_maxZoom, opt_tileSize, opt_corner) {
+  var corner = opt_corner !== undefined ?
+      opt_corner : ol.extent.Corner.TOP_LEFT;
+
+  var resolutions = ol.tilegrid.resolutionsFromExtent(
+      extent, opt_maxZoom, opt_tileSize);
+
+  return new ol.tilegrid.TileGrid({
+    extent: extent,
+    origin: ol.extent.getCorner(extent, corner),
+    resolutions: resolutions,
+    tileSize: opt_tileSize
+  });
+};
+
+
+/**
+ * Creates a tile grid with a standard XYZ tiling scheme.
+ * @param {olx.tilegrid.XYZOptions=} opt_options Tile grid options.
+ * @return {ol.tilegrid.TileGrid} Tile grid instance.
+ * @api
+ */
+ol.tilegrid.createXYZ = function(opt_options) {
+  var options = /** @type {olx.tilegrid.TileGridOptions} */ ({});
+  ol.obj.assign(options, opt_options !== undefined ?
+      opt_options : /** @type {olx.tilegrid.XYZOptions} */ ({}));
+  if (options.extent === undefined) {
+    options.extent = ol.proj.get('EPSG:3857').getExtent();
+  }
+  options.resolutions = ol.tilegrid.resolutionsFromExtent(
+      options.extent, options.maxZoom, options.tileSize);
+  delete options.maxZoom;
+
+  return new ol.tilegrid.TileGrid(options);
+};
+
+
+/**
+ * Create a resolutions array from an extent.  A zoom factor of 2 is assumed.
+ * @param {ol.Extent} extent Extent.
+ * @param {number=} opt_maxZoom Maximum zoom level (default is
+ *     ol.DEFAULT_MAX_ZOOM).
+ * @param {number|ol.Size=} opt_tileSize Tile size (default uses
+ *     ol.DEFAULT_TILE_SIZE).
+ * @return {!Array.<number>} Resolutions array.
+ */
+ol.tilegrid.resolutionsFromExtent = function(extent, opt_maxZoom, opt_tileSize) {
+  var maxZoom = opt_maxZoom !== undefined ?
+      opt_maxZoom : ol.DEFAULT_MAX_ZOOM;
+
+  var height = ol.extent.getHeight(extent);
+  var width = ol.extent.getWidth(extent);
+
+  var tileSize = ol.size.toSize(opt_tileSize !== undefined ?
+      opt_tileSize : ol.DEFAULT_TILE_SIZE);
+  var maxResolution = Math.max(
+      width / tileSize[0], height / tileSize[1]);
+
+  var length = maxZoom + 1;
+  var resolutions = new Array(length);
+  for (var z = 0; z < length; ++z) {
+    resolutions[z] = maxResolution / Math.pow(2, z);
+  }
+  return resolutions;
+};
+
+
+/**
+ * @param {ol.ProjectionLike} projection Projection.
+ * @param {number=} opt_maxZoom Maximum zoom level (default is
+ *     ol.DEFAULT_MAX_ZOOM).
+ * @param {ol.Size=} opt_tileSize Tile size (default uses ol.DEFAULT_TILE_SIZE).
+ * @param {ol.extent.Corner=} opt_corner Extent corner (default is
+ *     ol.extent.Corner.BOTTOM_LEFT).
+ * @return {!ol.tilegrid.TileGrid} TileGrid instance.
+ */
+ol.tilegrid.createForProjection = function(projection, opt_maxZoom, opt_tileSize, opt_corner) {
+  var extent = ol.tilegrid.extentFromProjection(projection);
+  return ol.tilegrid.createForExtent(
+      extent, opt_maxZoom, opt_tileSize, opt_corner);
+};
+
+
+/**
+ * Generate a tile grid extent from a projection.  If the projection has an
+ * extent, it is used.  If not, a global extent is assumed.
+ * @param {ol.ProjectionLike} projection Projection.
+ * @return {ol.Extent} Extent.
+ */
+ol.tilegrid.extentFromProjection = function(projection) {
+  projection = ol.proj.get(projection);
+  var extent = projection.getExtent();
+  if (!extent) {
+    var half = 180 * ol.proj.METERS_PER_UNIT[ol.proj.Units.DEGREES] /
+        projection.getMetersPerUnit();
+    extent = ol.extent.createOrUpdate(-half, -half, half, half);
+  }
+  return extent;
+};