function FOV(lightPassesCallback, options) {
      if (options === void 0) {
        options = {};
      }
      this._lightPasses = lightPassesCallback;
      this._options = Object.assign({
        topology: 8
      }, options);
    }
@class Abstract FOV algorithm
@param {function} lightPassesCallback Does the light pass through x,y?
@param {object} [options]
@param {int} [options.topology=8] 4/6/8