heli-agri/lib/tileurlfunction.js

HeliAgri is a high-performance, feature-packed library for creating interactive maps on the web. It can display map tiles, vector data and markers loaded from any source on any web page. OpenLayers has been developed to further the use of geographic infor

/**
 * @module ol/tileurlfunction
 */
import {assert} from './asserts.js';
import {modulo} from './math.js';
import {hash as tileCoordHash} from './tilecoord.js';

/**
 * @param {string} template Template.
 * @param {import("./tilegrid/TileGrid.js").default} tileGrid Tile grid.
 * @return {import("./Tile.js").UrlFunction} Tile URL function.
 */
export function createFromTemplate(template, tileGrid) {
  const zRegEx = /\{z\}/g;
  const xRegEx = /\{x\}/g;
  const yRegEx = /\{y\}/g;
  const dashYRegEx = /\{-y\}/g;
  return (
    /**
     * @param {import("./tilecoord.js").TileCoord} tileCoord Tile Coordinate.
     * @param {number} pixelRatio Pixel ratio.
     * @param {import("./proj/Projection.js").default} projection Projection.
     * @return {string|undefined} Tile URL.
     */
    function (tileCoord, pixelRatio, projection) {
      if (!tileCoord) {
        return undefined;
      }
      return template
        .replace(zRegEx, tileCoord[0].toString())
        .replace(xRegEx, tileCoord[1].toString())
        .replace(yRegEx, tileCoord[2].toString())
        .replace(dashYRegEx, function () {
          const z = tileCoord[0];
          const range = tileGrid.getFullTileRange(z);
          assert(range, 55); // The {-y} placeholder requires a tile grid with extent
          const y = range.getHeight() - tileCoord[2] - 1;
          return y.toString();
        });
    }
  );
}

/**
 * @param {Array<string>} templates Templates.
 * @param {import("./tilegrid/TileGrid.js").default} tileGrid Tile grid.
 * @return {import("./Tile.js").UrlFunction} Tile URL function.
 */
export function createFromTemplates(templates, tileGrid) {
  const len = templates.length;
  const tileUrlFunctions = new Array(len);
  for (let i = 0; i < len; ++i) {
    tileUrlFunctions[i] = createFromTemplate(templates[i], tileGrid);
  }
  return createFromTileUrlFunctions(tileUrlFunctions);
}

/**
 * @param {Array<import("./Tile.js").UrlFunction>} tileUrlFunctions Tile URL Functions.
 * @return {import("./Tile.js").UrlFunction} Tile URL function.
 */
export function createFromTileUrlFunctions(tileUrlFunctions) {
  if (tileUrlFunctions.length === 1) {
    return tileUrlFunctions[0];
  }
  return (
    /**
     * @param {import("./tilecoord.js").TileCoord} tileCoord Tile Coordinate.
     * @param {number} pixelRatio Pixel ratio.
     * @param {import("./proj/Projection.js").default} projection Projection.
     * @return {string|undefined} Tile URL.
     */
    function (tileCoord, pixelRatio, projection) {
      if (!tileCoord) {
        return undefined;
      }
      const h = tileCoordHash(tileCoord);
      const index = modulo(h, tileUrlFunctions.length);
      return tileUrlFunctions[index](tileCoord, pixelRatio, projection);
    }
  );
}

/**
 * @param {import("./tilecoord.js").TileCoord} tileCoord Tile coordinate.
 * @param {number} pixelRatio Pixel ratio.
 * @param {import("./proj/Projection.js").default} projection Projection.
 * @return {string|undefined} Tile URL.
 */
export function nullTileUrlFunction(tileCoord, pixelRatio, projection) {
  return undefined;
}

/**
 * @param {string} url URL.
 * @return {Array<string>} Array of urls.
 */
export function expandUrl(url) {
  const urls = [];
  let match = /\{([a-z])-([a-z])\}/.exec(url);
  if (match) {
    // char range
    const startCharCode = match[1].charCodeAt(0);
    const stopCharCode = match[2].charCodeAt(0);
    let charCode;
    for (charCode = startCharCode; charCode <= stopCharCode; ++charCode) {
      urls.push(url.replace(match[0], String.fromCharCode(charCode)));
    }
    return urls;
  }
  match = /\{(\d+)-(\d+)\}/.exec(url);
  if (match) {
    // number range
    const stop = parseInt(match[2], 10);
    for (let i = parseInt(match[1], 10); i <= stop; i++) {
      urls.push(url.replace(match[0], i.toString()));
    }
    return urls;
  }
  urls.push(url);
  return urls;
}