Source: bemap-model/bemap-rasterLayer.js

/**
 * BeNomad BeMap JavaScript API - RasterLayer class
 * Generic raster tile layer for satellite imagery, custom tile servers, etc.
 */

/**
 * @classdesc
 * Layer for raster tile sources (satellite, custom tiles).
 * @public
 * @constructor
 * @extends {bemap.Layer}
 * @param {Object} options
 * @param {String} options.url Raster tile URL template with {z}/{x}/{y}.
 * @param {Number} options.tileSize Tile size in pixels (default: 256).
 * @param {Number} options.opacity Layer opacity 0-1 (default: 1).
 * @param {String} options.attribution Attribution text.
 */
bemap.RasterLayer = function(options) {
  var opts = options || {};

  this.url = opts.url ? opts.url : null;
  this.tileSize = opts.tileSize ? opts.tileSize : 256;
  this.opacity = opts.opacity !== undefined ? opts.opacity : 1;
  this.attribution = opts.attribution ? opts.attribution : '';

  bemap.Layer.call(this, options);
};
bemap.inherits(bemap.RasterLayer, bemap.Layer);