cesium
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CesiumJS is a JavaScript library for creating 3D globes and 2D maps in a web browser without a plugin.
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JavaScript
import Cartesian2 from '../Core/Cartesian2.js';
import Cartographic from '../Core/Cartographic.js';
import defaultValue from '../Core/defaultValue.js';
import defined from '../Core/defined.js';
import DeveloperError from '../Core/DeveloperError.js';
import GeographicProjection from '../Core/GeographicProjection.js';
import GeographicTilingScheme from '../Core/GeographicTilingScheme.js';
import Rectangle from '../Core/Rectangle.js';
import Resource from '../Core/Resource.js';
import RuntimeError from '../Core/RuntimeError.js';
import TileProviderError from '../Core/TileProviderError.js';
import WebMercatorTilingScheme from '../Core/WebMercatorTilingScheme.js';
import when from '../ThirdParty/when.js';
import UrlTemplateImageryProvider from './UrlTemplateImageryProvider.js';
/**
* An imagery provider that provides tiled imagery as generated by
* {@link http://www.maptiler.org/|MapTiler}, {@link http://www.klokan.cz/projects/gdal2tiles/|GDAL2Tiles}, etc.
*
* @alias TileMapServiceImageryProvider
* @constructor
*
* @param {Object} [options] Object with the following properties:
* @param {Resource|String|Promise<Resource>|Promise<String>} [options.url='.'] Path to image tiles on server.
* @param {String} [options.fileExtension='png'] The file extension for images on the server.
* @param {Credit|String} [options.credit=''] A credit for the data source, which is displayed on the canvas.
* @param {Number} [options.minimumLevel=0] The minimum level-of-detail supported by the imagery provider. Take care when specifying
* this that the number of tiles at the minimum level is small, such as four or less. A larger number is likely
* to result in rendering problems.
* @param {Number} [options.maximumLevel] The maximum level-of-detail supported by the imagery provider, or undefined if there is no limit.
* @param {Rectangle} [options.rectangle=Rectangle.MAX_VALUE] The rectangle, in radians, covered by the image.
* @param {TilingScheme} [options.tilingScheme] The tiling scheme specifying how the ellipsoidal
* surface is broken into tiles. If this parameter is not provided, a {@link WebMercatorTilingScheme}
* is used.
* @param {Ellipsoid} [options.ellipsoid] The ellipsoid. If the tilingScheme is specified,
* this parameter is ignored and the tiling scheme's ellipsoid is used instead. If neither
* parameter is specified, the WGS84 ellipsoid is used.
* @param {Number} [options.tileWidth=256] Pixel width of image tiles.
* @param {Number} [options.tileHeight=256] Pixel height of image tiles.
* @param {Boolean} [options.flipXY] Older versions of gdal2tiles.py flipped X and Y values in tilemapresource.xml.
* Specifying this option will do the same, allowing for loading of these incorrect tilesets.
* @returns {UrlTemplateImageryProvider} The imagery provider.
*
* @see ArcGisMapServerImageryProvider
* @see BingMapsImageryProvider
* @see GoogleEarthEnterpriseMapsProvider
* @see OpenStreetMapImageryProvider
* @see SingleTileImageryProvider
* @see WebMapServiceImageryProvider
* @see WebMapTileServiceImageryProvider
* @see UrlTemplateImageryProvider
*
* @example
* var tms = new Cesium.TileMapServiceImageryProvider({
* url : '../images/cesium_maptiler/Cesium_Logo_Color',
* fileExtension: 'png',
* maximumLevel: 4,
* rectangle: new Cesium.Rectangle(
* Cesium.Math.toRadians(-120.0),
* Cesium.Math.toRadians(20.0),
* Cesium.Math.toRadians(-60.0),
* Cesium.Math.toRadians(40.0))
* });
*/
function TileMapServiceImageryProvider(options) {
options = defaultValue(options, defaultValue.EMPTY_OBJECT);
//>>includeStart('debug', pragmas.debug);
if (!defined(options.url)) {
throw new DeveloperError('options.url is required.');
}
//>>includeEnd('debug');
var deferred = when.defer();
UrlTemplateImageryProvider.call(this, deferred.promise);
this._tmsResource = undefined;
this._xmlResource = undefined;
this._options = options;
this._deferred = deferred;
this._metadataError = undefined;
this._metadataSuccess = this._metadataSuccess.bind(this);
this._metadataFailure = this._metadataFailure.bind(this);
this._requestMetadata = this._requestMetadata.bind(this);
var resource;
var that = this;
when(options.url)
.then(function(url) {
resource = Resource.createIfNeeded(url);
resource.appendForwardSlash();
that._tmsResource = resource;
that._xmlResource = resource.getDerivedResource({
url : 'tilemapresource.xml'
});
that._requestMetadata();
})
.otherwise(function(e) {
deferred.reject(e);
});
}
if (defined(Object.create)) {
TileMapServiceImageryProvider.prototype = Object.create(UrlTemplateImageryProvider.prototype);
TileMapServiceImageryProvider.prototype.constructor = TileMapServiceImageryProvider;
}
TileMapServiceImageryProvider.prototype._requestMetadata = function() {
// Try to load remaining parameters from XML
this._xmlResource.fetchXML().then(this._metadataSuccess).otherwise(this._metadataFailure);
};
TileMapServiceImageryProvider.prototype._metadataSuccess = function(xml) {
var tileFormatRegex = /tileformat/i;
var tileSetRegex = /tileset/i;
var tileSetsRegex = /tilesets/i;
var bboxRegex = /boundingbox/i;
var format, bbox, tilesets;
var tilesetsList = []; //list of TileSets
var xmlResource = this._xmlResource;
var metadataError = this._metadataError;
var deferred = this._deferred;
var requestMetadata = this._requestMetadata;
// Allowing options properties (already copied to that) to override XML values
// Iterate XML Document nodes for properties
var nodeList = xml.childNodes[0].childNodes;
for (var i = 0; i < nodeList.length; i++) {
if (tileFormatRegex.test(nodeList.item(i).nodeName)) {
format = nodeList.item(i);
} else if (tileSetsRegex.test(nodeList.item(i).nodeName)) {
tilesets = nodeList.item(i); // Node list of TileSets
var tileSetNodes = nodeList.item(i).childNodes;
// Iterate the nodes to find all TileSets
for (var j = 0; j < tileSetNodes.length; j++) {
if (tileSetRegex.test(tileSetNodes.item(j).nodeName)) {
// Add them to tilesets list
tilesetsList.push(tileSetNodes.item(j));
}
}
} else if (bboxRegex.test(nodeList.item(i).nodeName)) {
bbox = nodeList.item(i);
}
}
var message;
if (!defined(tilesets) || !defined(bbox)) {
message = 'Unable to find expected tilesets or bbox attributes in ' + xmlResource.url + '.';
metadataError = TileProviderError.handleError(metadataError, this, this.errorEvent, message, undefined, undefined, undefined, requestMetadata);
if (!metadataError.retry) {
deferred.reject(new RuntimeError(message));
}
this._metadataError = metadataError;
return;
}
var options = this._options;
var fileExtension = defaultValue(options.fileExtension, format.getAttribute('extension'));
var tileWidth = defaultValue(options.tileWidth, parseInt(format.getAttribute('width'), 10));
var tileHeight = defaultValue(options.tileHeight, parseInt(format.getAttribute('height'), 10));
var minimumLevel = defaultValue(options.minimumLevel, parseInt(tilesetsList[0].getAttribute('order'), 10));
var maximumLevel = defaultValue(options.maximumLevel, parseInt(tilesetsList[tilesetsList.length - 1].getAttribute('order'), 10));
var tilingSchemeName = tilesets.getAttribute('profile');
var tilingScheme = options.tilingScheme;
if (!defined(tilingScheme)) {
if (tilingSchemeName === 'geodetic' || tilingSchemeName === 'global-geodetic') {
tilingScheme = new GeographicTilingScheme({ellipsoid : options.ellipsoid});
} else if (tilingSchemeName === 'mercator' || tilingSchemeName === 'global-mercator') {
tilingScheme = new WebMercatorTilingScheme({ellipsoid : options.ellipsoid});
} else {
message = xmlResource.url + 'specifies an unsupported profile attribute, ' + tilingSchemeName + '.';
metadataError = TileProviderError.handleError(metadataError, this, this.errorEvent, message, undefined, undefined, undefined, requestMetadata);
if (!metadataError.retry) {
deferred.reject(new RuntimeError(message));
}
this._metadataError = metadataError;
return;
}
}
// rectangle handling
var rectangle = Rectangle.clone(options.rectangle);
if (!defined(rectangle)) {
var sw;
var ne;
var swXY;
var neXY;
// In older versions of gdal x and y values were flipped, which is why we check for an option to flip
// the values here as well. Unfortunately there is no way to autodetect whether flipping is needed.
var flipXY = defaultValue(options.flipXY, false);
if (flipXY) {
swXY = new Cartesian2(parseFloat(bbox.getAttribute('miny')), parseFloat(bbox.getAttribute('minx')));
neXY = new Cartesian2(parseFloat(bbox.getAttribute('maxy')), parseFloat(bbox.getAttribute('maxx')));
} else {
swXY = new Cartesian2(parseFloat(bbox.getAttribute('minx')), parseFloat(bbox.getAttribute('miny')));
neXY = new Cartesian2(parseFloat(bbox.getAttribute('maxx')), parseFloat(bbox.getAttribute('maxy')));
}
// Determine based on the profile attribute if this tileset was generated by gdal2tiles.py, which
// uses 'mercator' and 'geodetic' profiles, or by a tool compliant with the TMS standard, which is
// 'global-mercator' and 'global-geodetic' profiles. In the gdal2Tiles case, X and Y are always in
// geodetic degrees.
var isGdal2tiles = tilingSchemeName === 'geodetic' || tilingSchemeName === 'mercator';
if (tilingScheme.projection instanceof GeographicProjection || isGdal2tiles) {
sw = Cartographic.fromDegrees(swXY.x, swXY.y);
ne = Cartographic.fromDegrees(neXY.x, neXY.y);
} else {
var projection = tilingScheme.projection;
sw = projection.unproject(swXY);
ne = projection.unproject(neXY);
}
rectangle = new Rectangle(sw.longitude, sw.latitude, ne.longitude, ne.latitude);
}
// The rectangle must not be outside the bounds allowed by the tiling scheme.
if (rectangle.west < tilingScheme.rectangle.west) {
rectangle.west = tilingScheme.rectangle.west;
}
if (rectangle.east > tilingScheme.rectangle.east) {
rectangle.east = tilingScheme.rectangle.east;
}
if (rectangle.south < tilingScheme.rectangle.south) {
rectangle.south = tilingScheme.rectangle.south;
}
if (rectangle.north > tilingScheme.rectangle.north) {
rectangle.north = tilingScheme.rectangle.north;
}
// Check the number of tiles at the minimum level. If it's more than four,
// try requesting the lower levels anyway, because starting at the higher minimum
// level will cause too many tiles to be downloaded and rendered.
var swTile = tilingScheme.positionToTileXY(Rectangle.southwest(rectangle), minimumLevel);
var neTile = tilingScheme.positionToTileXY(Rectangle.northeast(rectangle), minimumLevel);
var tileCount = (Math.abs(neTile.x - swTile.x) + 1) * (Math.abs(neTile.y - swTile.y) + 1);
if (tileCount > 4) {
minimumLevel = 0;
}
var templateResource = this._tmsResource.getDerivedResource({
url : '{z}/{x}/{reverseY}.' + fileExtension
});
deferred.resolve({
url : templateResource,
tilingScheme : tilingScheme,
rectangle : rectangle,
tileWidth : tileWidth,
tileHeight : tileHeight,
minimumLevel : minimumLevel,
maximumLevel : maximumLevel,
tileDiscardPolicy : options.tileDiscardPolicy,
credit : options.credit
});
};
TileMapServiceImageryProvider.prototype._metadataFailure = function(error) {
// Can't load XML, still allow options and defaults
var options = this._options;
var fileExtension = defaultValue(options.fileExtension, 'png');
var tileWidth = defaultValue(options.tileWidth, 256);
var tileHeight = defaultValue(options.tileHeight, 256);
var minimumLevel = defaultValue(options.minimumLevel, 0);
var maximumLevel = options.maximumLevel;
var tilingScheme = defined(options.tilingScheme) ? options.tilingScheme : new WebMercatorTilingScheme({ellipsoid : options.ellipsoid});
var rectangle = defaultValue(options.rectangle, tilingScheme.rectangle);
var templateResource = this._tmsResource.getDerivedResource({
url : '{z}/{x}/{reverseY}.' + fileExtension
});
this._deferred.resolve({
url : templateResource,
tilingScheme : tilingScheme,
rectangle : rectangle,
tileWidth : tileWidth,
tileHeight : tileHeight,
minimumLevel : minimumLevel,
maximumLevel : maximumLevel,
tileDiscardPolicy : options.tileDiscardPolicy,
credit : options.credit
});
};
export default TileMapServiceImageryProvider;