Function fun

src/openlayers/core/MapExtend.js:13–26

(layer, coordinate, resolution, callback, pixel, e)

 */
export var MapExtend = function () {
    const fun = function (layer, coordinate, resolution, callback, pixel, e) {
        if (layer instanceof LayerGroup) {
            layer.getLayers().forEach(function (subLayer) {
                fun(subLayer, coordinate, resolution, callback, pixel, e)
            });
        } else {
            //当前高效率点图层满足筛选条件/并且可视时，可被选中：
            if (layer.getSource()._forEachFeatureAtCoordinate) {
                layer.getSource()._forEachFeatureAtCoordinate(coordinate, resolution, (feature) => {
                    callback(feature, layer)
                }, pixel, e);
            }
        }
    }
    olMap.prototype.forEachFeatureAtPixelDefault = olMap.prototype.forEachFeatureAtPixel;

    olMap.prototype.forEachFeatureAtPixel = olMap.prototype.Tc = function (pixel, callback, opt_options, e) {