Openlayers3 加载百度地图，天地图

openlayers3 加载百度地图： var projection = ol.proj.get("EPSG:3857"); var resolutions = []; for(var

openlayers3 加载百度地图：

 var projection = ol.proj.get("EPSG:3857");    var resolutions = [];    for(var i=0; i<19; i++){        resolutions[i] = Math.pow(2, 18-i);    }    var tilegrid  = new ol.tilegrid.TileGrid({        origin: [0,0],        resolutions: resolutions    });    var baidu_source = new ol.source.TileImage({        projection: projection,        tileGrid: tilegrid,        tileUrlFunction: function(tileCoord, pixelRatio, proj){            if(!tileCoord){                return "";            }            var z = tileCoord[0];            var x = tileCoord[1];            var y = tileCoord[2];            if(x<0){                x = "M"+(-x);            }            if(y<0){                y = "M"+(-y);            }            return "http://online3.map.bdimg.com/onlinelabel/?qt=tile&x="+x+"&y="+y+"&z="+z+"&styles=pl&udt=20151021&scaler=1&p=1";        }    });    var baidu_layer = new ol.layer.Tile({        source: baidu_source    });    var map = new ol.Map({        target: 'map',        layers: [baidu_layer],        view: new ol.View({            center:  [12959773,4853101],            zoom: 12        })    });

openlayers3 加载天地图：

路网var tian_di_tu_road_layer = new ol.layer.Tile({    title: "天地图路网",    source: new ol.source.XYZ({        url: "http://t4.tianditu.com/DataServer?T=vec_w&x={x}&y={y}&l={z}"    })});map.addLayer(tian_di_tu_road_layer);注记var tian_di_tu_annotation = new ol.layer.Tile({    title: "天地图文字标注",    source: new ol.source.XYZ({        url: 'http://t3.tianditu.com/DataServer?T=cva_w&x={x}&y={y}&l={z}'    })});map.addLayer(tian_di_tu_annotation);卫星影像var tian_di_tu_satellite_layer = new ol.layer.Tile({    title: "天地图卫星影像",    source: new ol.source.XYZ({        url: 'http://t3.tianditu.com/DataServer?T=img_w&x={x}&y={y}&l={z}'    })});map.addLayer(tian_di_tu_satellite_layer);