WebMapTileServiceImageryProvider.js

import combine from "../Core/combine.js";
import Credit from "../Core/Credit.js";
import defaultValue from "../Core/defaultValue.js";
import defined from "../Core/defined.js";
import DeveloperError from "../Core/DeveloperError.js";
import Event from "../Core/Event.js";
import Rectangle from "../Core/Rectangle.js";
import Resource from "../Core/Resource.js";
import WebMercatorTilingScheme from "../Core/WebMercatorTilingScheme.js";
import ImageryProvider from "./ImageryProvider.js";
import TimeDynamicImagery from "./TimeDynamicImagery.js";

const defaultParameters = Object.freeze({
  service: "WMTS",
  version: "1.0.0",
  request: "GetTile",
});

/**
 * @typedef {object} WebMapTileServiceImageryProvider.ConstructorOptions
 *
 * Initialization options for the WebMapTileServiceImageryProvider constructor
 *
 * @property {Resource|string} url The base URL for the WMTS GetTile operation (for KVP-encoded requests) or the tile-URL template (for RESTful requests). The tile-URL template should contain the following variables: {style}, {TileMatrixSet}, {TileMatrix}, {TileRow}, {TileCol}. The first two are optional if actual values are hardcoded or not required by the server. The {s} keyword may be used to specify subdomains.
 * @property {string} [format='image/jpeg'] The MIME type for images to retrieve from the server.
 * @property {string} layer The layer name for WMTS requests.
 * @property {string} style The style name for WMTS requests.
 * @property {string} tileMatrixSetID The identifier of the TileMatrixSet to use for WMTS requests.
 * @property {Array} [tileMatrixLabels] A list of identifiers in the TileMatrix to use for WMTS requests, one per TileMatrix level.
 * @property {Clock} [clock] A Clock instance that is used when determining the value for the time dimension. Required when `times` is specified.
 * @property {TimeIntervalCollection} [times] TimeIntervalCollection with its <code>data</code> property being an object containing time dynamic dimension and their values.
 * @property {object} [dimensions] A object containing static dimensions and their values.
 * @property {number} [tileWidth=256] The tile width in pixels.
 * @property {number} [tileHeight=256] The tile height in pixels.
 * @property {TilingScheme} [tilingScheme] The tiling scheme corresponding to the organization of the tiles in the TileMatrixSet.
 * @property {Rectangle} [rectangle=Rectangle.MAX_VALUE] The rectangle covered by the layer.
 * @property {number} [minimumLevel=0] The minimum level-of-detail supported by the imagery provider.
 * @property {number} [maximumLevel] The maximum level-of-detail supported by the imagery provider, or undefined if there is no limit.
 * @property {Ellipsoid} [ellipsoid] The ellipsoid.  If not specified, the WGS84 ellipsoid is used.
 * @property {Credit|string} [credit] A credit for the data source, which is displayed on the canvas.
 * @property {string|string[]} [subdomains='abc'] The subdomains to use for the <code>{s}</code> placeholder in the URL template.
 *                          If this parameter is a single string, each character in the string is a subdomain.  If it is
 *                          an array, each element in the array is a subdomain.
 */

/**
 * Provides tiled imagery served by {@link http://www.opengeospatial.org/standards/wmts|WMTS 1.0.0} compliant servers.
 * This provider supports HTTP KVP-encoded and RESTful GetTile requests, but does not yet support the SOAP encoding.
 *
 * @alias WebMapTileServiceImageryProvider
 * @constructor
 *
 * @param {WebMapTileServiceImageryProvider.ConstructorOptions} options Object describing initialization options
 *
 * @demo {@link https://sandcastle.cesium.com/index.html?src=Web%20Map%20Tile%20Service%20with%20Time.html|Cesium Sandcastle Web Map Tile Service with Time Demo}
 *
 * @example
 * // Example 1. USGS shaded relief tiles (KVP)
 * const shadedRelief1 = new Cesium.WebMapTileServiceImageryProvider({
 *     url : 'http://basemap.nationalmap.gov/arcgis/rest/services/USGSShadedReliefOnly/MapServer/WMTS',
 *     layer : 'USGSShadedReliefOnly',
 *     style : 'default',
 *     format : 'image/jpeg',
 *     tileMatrixSetID : 'default028mm',
 *     // tileMatrixLabels : ['default028mm:0', 'default028mm:1', 'default028mm:2' ...],
 *     maximumLevel: 19,
 *     credit : new Cesium.Credit('U. S. Geological Survey')
 * });
 * viewer.imageryLayers.addImageryProvider(shadedRelief1);
 *
 * @example
 * // Example 2. USGS shaded relief tiles (RESTful)
 * const shadedRelief2 = new Cesium.WebMapTileServiceImageryProvider({
 *     url : 'http://basemap.nationalmap.gov/arcgis/rest/services/USGSShadedReliefOnly/MapServer/WMTS/tile/1.0.0/USGSShadedReliefOnly/{Style}/{TileMatrixSet}/{TileMatrix}/{TileRow}/{TileCol}.jpg',
 *     layer : 'USGSShadedReliefOnly',
 *     style : 'default',
 *     format : 'image/jpeg',
 *     tileMatrixSetID : 'default028mm',
 *     maximumLevel: 19,
 *     credit : new Cesium.Credit('U. S. Geological Survey')
 * });
 * viewer.imageryLayers.addImageryProvider(shadedRelief2);
 *
 * @example
 * // Example 3. NASA time dynamic weather data (RESTful)
 * const times = Cesium.TimeIntervalCollection.fromIso8601({
 *     iso8601: '2015-07-30/2017-06-16/P1D',
 *     dataCallback: function dataCallback(interval, index) {
 *         return {
 *             Time: Cesium.JulianDate.toIso8601(interval.start)
 *         };
 *     }
 * });
 * const weather = new Cesium.WebMapTileServiceImageryProvider({
 *     url : 'https://gibs.earthdata.nasa.gov/wmts/epsg4326/best/AMSR2_Snow_Water_Equivalent/default/{Time}/{TileMatrixSet}/{TileMatrix}/{TileRow}/{TileCol}.png',
 *     layer : 'AMSR2_Snow_Water_Equivalent',
 *     style : 'default',
 *     tileMatrixSetID : '2km',
 *     maximumLevel : 5,
 *     format : 'image/png',
 *     clock: clock,
 *     times: times,
 *     credit : new Cesium.Credit('NASA Global Imagery Browse Services for EOSDIS')
 * });
 * viewer.imageryLayers.addImageryProvider(weather);
 *
 * @see ArcGisMapServerImageryProvider
 * @see BingMapsImageryProvider
 * @see GoogleEarthEnterpriseMapsProvider
 * @see OpenStreetMapImageryProvider
 * @see SingleTileImageryProvider
 * @see TileMapServiceImageryProvider
 * @see WebMapServiceImageryProvider
 * @see UrlTemplateImageryProvider
 */
function WebMapTileServiceImageryProvider(options) {
  options = defaultValue(options, defaultValue.EMPTY_OBJECT);

  //>>includeStart('debug', pragmas.debug);
  if (!defined(options.url)) {
    throw new DeveloperError("options.url is required.");
  }
  if (!defined(options.layer)) {
    throw new DeveloperError("options.layer is required.");
  }
  if (!defined(options.style)) {
    throw new DeveloperError("options.style is required.");
  }
  if (!defined(options.tileMatrixSetID)) {
    throw new DeveloperError("options.tileMatrixSetID is required.");
  }
  if (defined(options.times) && !defined(options.clock)) {
    throw new DeveloperError(
      "options.times was specified, so options.clock is required."
    );
  }
  //>>includeEnd('debug');

  this._defaultAlpha = undefined;
  this._defaultNightAlpha = undefined;
  this._defaultDayAlpha = undefined;
  this._defaultBrightness = undefined;
  this._defaultContrast = undefined;
  this._defaultHue = undefined;
  this._defaultSaturation = undefined;
  this._defaultGamma = undefined;
  this._defaultMinificationFilter = undefined;
  this._defaultMagnificationFilter = undefined;

  const resource = Resource.createIfNeeded(options.url);

  const style = options.style;
  const tileMatrixSetID = options.tileMatrixSetID;
  const url = resource.url;

  const bracketMatch = url.match(/{/g);
  if (
    !defined(bracketMatch) ||
    (bracketMatch.length === 1 && /{s}/.test(url))
  ) {
    resource.setQueryParameters(defaultParameters);
    this._useKvp = true;
  } else {
    const templateValues = {
      style: style,
      Style: style,
      TileMatrixSet: tileMatrixSetID,
    };

    resource.setTemplateValues(templateValues);
    this._useKvp = false;
  }

  this._resource = resource;
  this._layer = options.layer;
  this._style = style;
  this._tileMatrixSetID = tileMatrixSetID;
  this._tileMatrixLabels = options.tileMatrixLabels;
  this._format = defaultValue(options.format, "image/jpeg");
  this._tileDiscardPolicy = options.tileDiscardPolicy;

  this._tilingScheme = defined(options.tilingScheme)
    ? options.tilingScheme
    : new WebMercatorTilingScheme({ ellipsoid: options.ellipsoid });
  this._tileWidth = defaultValue(options.tileWidth, 256);
  this._tileHeight = defaultValue(options.tileHeight, 256);

  this._minimumLevel = defaultValue(options.minimumLevel, 0);
  this._maximumLevel = options.maximumLevel;

  this._rectangle = defaultValue(
    options.rectangle,
    this._tilingScheme.rectangle
  );
  this._dimensions = options.dimensions;

  const that = this;
  this._reload = undefined;
  if (defined(options.times)) {
    this._timeDynamicImagery = new TimeDynamicImagery({
      clock: options.clock,
      times: options.times,
      requestImageFunction: function (x, y, level, request, interval) {
        return requestImage(that, x, y, level, request, interval);
      },
      reloadFunction: function () {
        if (defined(that._reload)) {
          that._reload();
        }
      },
    });
  }

  // Check the number of tiles at the minimum level.  If it's more than four,
  // throw an exception, because starting at the higher minimum
  // level will cause too many tiles to be downloaded and rendered.
  const swTile = this._tilingScheme.positionToTileXY(
    Rectangle.southwest(this._rectangle),
    this._minimumLevel
  );
  const neTile = this._tilingScheme.positionToTileXY(
    Rectangle.northeast(this._rectangle),
    this._minimumLevel
  );
  const tileCount =
    (Math.abs(neTile.x - swTile.x) + 1) * (Math.abs(neTile.y - swTile.y) + 1);
  //>>includeStart('debug', pragmas.debug);
  if (tileCount > 4) {
    throw new DeveloperError(
      `The imagery provider's rectangle and minimumLevel indicate that there are ${tileCount} tiles at the minimum level. Imagery providers with more than four tiles at the minimum level are not supported.`
    );
  }
  //>>includeEnd('debug');

  this._errorEvent = new Event();

  const credit = options.credit;
  this._credit = typeof credit === "string" ? new Credit(credit) : credit;

  this._subdomains = options.subdomains;
  if (Array.isArray(this._subdomains)) {
    this._subdomains = this._subdomains.slice();
  } else if (defined(this._subdomains) && this._subdomains.length > 0) {
    this._subdomains = this._subdomains.split("");
  } else {
    this._subdomains = ["a", "b", "c"];
  }
}

function requestImage(imageryProvider, col, row, level, request, interval) {
  const labels = imageryProvider._tileMatrixLabels;
  const tileMatrix = defined(labels) ? labels[level] : level.toString();
  const subdomains = imageryProvider._subdomains;
  const staticDimensions = imageryProvider._dimensions;
  const dynamicIntervalData = defined(interval) ? interval.data : undefined;

  let resource;
  let templateValues;
  if (!imageryProvider._useKvp) {
    templateValues = {
      TileMatrix: tileMatrix,
      TileRow: row.toString(),
      TileCol: col.toString(),
      s: subdomains[(col + row + level) % subdomains.length],
    };

    resource = imageryProvider._resource.getDerivedResource({
      request: request,
    });
    resource.setTemplateValues(templateValues);

    if (defined(staticDimensions)) {
      resource.setTemplateValues(staticDimensions);
    }

    if (defined(dynamicIntervalData)) {
      resource.setTemplateValues(dynamicIntervalData);
    }
  } else {
    // build KVP request
    let query = {};
    query.tilematrix = tileMatrix;
    query.layer = imageryProvider._layer;
    query.style = imageryProvider._style;
    query.tilerow = row;
    query.tilecol = col;
    query.tilematrixset = imageryProvider._tileMatrixSetID;
    query.format = imageryProvider._format;

    if (defined(staticDimensions)) {
      query = combine(query, staticDimensions);
    }

    if (defined(dynamicIntervalData)) {
      query = combine(query, dynamicIntervalData);
    }

    templateValues = {
      s: subdomains[(col + row + level) % subdomains.length],
    };

    resource = imageryProvider._resource.getDerivedResource({
      queryParameters: query,
      request: request,
    });
    resource.setTemplateValues(templateValues);
  }

  return ImageryProvider.loadImage(imageryProvider, resource);
}

Object.defineProperties(WebMapTileServiceImageryProvider.prototype, {
  /**
   * Gets the URL of the service hosting the imagery.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {string}
   * @readonly
   */
  url: {
    get: function () {
      return this._resource.url;
    },
  },

  /**
   * Gets the proxy used by this provider.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {Proxy}
   * @readonly
   */
  proxy: {
    get: function () {
      return this._resource.proxy;
    },
  },

  /**
   * Gets the width of each tile, in pixels.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {number}
   * @readonly
   */
  tileWidth: {
    get: function () {
      return this._tileWidth;
    },
  },

  /**
   * Gets the height of each tile, in pixels.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {number}
   * @readonly
   */
  tileHeight: {
    get: function () {
      return this._tileHeight;
    },
  },

  /**
   * Gets the maximum level-of-detail that can be requested.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {number|undefined}
   * @readonly
   */
  maximumLevel: {
    get: function () {
      return this._maximumLevel;
    },
  },

  /**
   * Gets the minimum level-of-detail that can be requested.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {number}
   * @readonly
   */
  minimumLevel: {
    get: function () {
      return this._minimumLevel;
    },
  },

  /**
   * Gets the tiling scheme used by this provider.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {TilingScheme}
   * @readonly
   */
  tilingScheme: {
    get: function () {
      return this._tilingScheme;
    },
  },

  /**
   * Gets the rectangle, in radians, of the imagery provided by this instance.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {Rectangle}
   * @readonly
   */
  rectangle: {
    get: function () {
      return this._rectangle;
    },
  },

  /**
   * Gets the tile discard policy.  If not undefined, the discard policy is responsible
   * for filtering out "missing" tiles via its shouldDiscardImage function.  If this function
   * returns undefined, no tiles are filtered.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {TileDiscardPolicy}
   * @readonly
   */
  tileDiscardPolicy: {
    get: function () {
      return this._tileDiscardPolicy;
    },
  },

  /**
   * Gets an event that is raised when the imagery provider encounters an asynchronous error.  By subscribing
   * to the event, you will be notified of the error and can potentially recover from it.  Event listeners
   * are passed an instance of {@link TileProviderError}.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {Event}
   * @readonly
   */
  errorEvent: {
    get: function () {
      return this._errorEvent;
    },
  },

  /**
   * Gets the mime type of images returned by this imagery provider.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {string}
   * @readonly
   */
  format: {
    get: function () {
      return this._format;
    },
  },

  /**
   * Gets the credit to display when this imagery provider is active.  Typically this is used to credit
   * the source of the imagery.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {Credit}
   * @readonly
   */
  credit: {
    get: function () {
      return this._credit;
    },
  },

  /**
   * Gets a value indicating whether or not the images provided by this imagery provider
   * include an alpha channel.  If this property is false, an alpha channel, if present, will
   * be ignored.  If this property is true, any images without an alpha channel will be treated
   * as if their alpha is 1.0 everywhere.  When this property is false, memory usage
   * and texture upload time are reduced.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {boolean}
   * @readonly
   */
  hasAlphaChannel: {
    get: function () {
      return true;
    },
  },
  /**
   * Gets or sets a clock that is used to get keep the time used for time dynamic parameters.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {Clock}
   */
  clock: {
    get: function () {
      return this._timeDynamicImagery.clock;
    },
    set: function (value) {
      this._timeDynamicImagery.clock = value;
    },
  },
  /**
   * Gets or sets a time interval collection that is used to get time dynamic parameters. The data of each
   * TimeInterval is an object containing the keys and values of the properties that are used during
   * tile requests.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {TimeIntervalCollection}
   */
  times: {
    get: function () {
      return this._timeDynamicImagery.times;
    },
    set: function (value) {
      this._timeDynamicImagery.times = value;
    },
  },
  /**
   * Gets or sets an object that contains static dimensions and their values.
   * @memberof WebMapTileServiceImageryProvider.prototype
   * @type {object}
   */
  dimensions: {
    get: function () {
      return this._dimensions;
    },
    set: function (value) {
      if (this._dimensions !== value) {
        this._dimensions = value;
        if (defined(this._reload)) {
          this._reload();
        }
      }
    },
  },
});

/**
 * Gets the credits to be displayed when a given tile is displayed.
 *
 * @param {number} x The tile X coordinate.
 * @param {number} y The tile Y coordinate.
 * @param {number} level The tile level;
 * @returns {Credit[]} The credits to be displayed when the tile is displayed.
 */
WebMapTileServiceImageryProvider.prototype.getTileCredits = function (
  x,
  y,
  level
) {
  return undefined;
};

/**
 * Requests the image for a given tile.
 *
 * @param {number} x The tile X coordinate.
 * @param {number} y The tile Y coordinate.
 * @param {number} level The tile level.
 * @param {Request} [request] The request object. Intended for internal use only.
 * @returns {Promise<ImageryTypes>|undefined} A promise for the image that will resolve when the image is available, or
 *          undefined if there are too many active requests to the server, and the request should be retried later.
 */
WebMapTileServiceImageryProvider.prototype.requestImage = function (
  x,
  y,
  level,
  request
) {
  let result;
  const timeDynamicImagery = this._timeDynamicImagery;
  let currentInterval;

  // Try and load from cache
  if (defined(timeDynamicImagery)) {
    currentInterval = timeDynamicImagery.currentInterval;
    result = timeDynamicImagery.getFromCache(x, y, level, request);
  }

  // Couldn't load from cache
  if (!defined(result)) {
    result = requestImage(this, x, y, level, request, currentInterval);
  }

  // If we are approaching an interval, preload this tile in the next interval
  if (defined(result) && defined(timeDynamicImagery)) {
    timeDynamicImagery.checkApproachingInterval(x, y, level, request);
  }

  return result;
};

/**
 * Picking features is not currently supported by this imagery provider, so this function simply returns
 * undefined.
 *
 * @param {number} x The tile X coordinate.
 * @param {number} y The tile Y coordinate.
 * @param {number} level The tile level.
 * @param {number} longitude The longitude at which to pick features.
 * @param {number} latitude  The latitude at which to pick features.
 * @return {undefined} Undefined since picking is not supported.
 */
WebMapTileServiceImageryProvider.prototype.pickFeatures = function (
  x,
  y,
  level,
  longitude,
  latitude
) {
  return undefined;
};
export default WebMapTileServiceImageryProvider;