openlayer读取三种类型的本地瓦片的计算公式

1.arcgis server瓦片的计算公式及geturl方法：

getURL: function(bounds){

     var lon1=bounds.left;

     var lat1=bounds.top;

     var lon2=bounds.right;

     var lat2=bounds.bottom;

        var picHeight=256;    //图片大小 

        var picResolution,picRow,picCol;   //分辨率,所求图片行号,列号

        var tileOriginX,tileOriginY;    //切图原点

        var iResolution = this.map.getResolution();

        var temp1=new Array();

        var i,zoom=0,path;    //zoom代表缩放级别；

       

  tileOriginX=this.tileOrigin.lon;

  tileOriginY=this.tileOrigin.lat;

  //计算zoom

  zoom=this.map.getZoom();

  //获得行列号(使用瓦片的中心点经纬度计算)

   picRow=Math.ceil(Math.abs((tileOriginY-(lat1+lat2)/2)/(iResolution*picHeight)))-1;

   picCol=Math.ceil(Math.abs((tileOriginX-(lon1+lon2)/2)/(iResolution*picHeight)))-1; 

  //计算瓦片路径,把级别、行列十进制转化为十六进制

  zoom=zoom.toString(16);

  picRow=picRow.toString(16);

  picCol=picCol.toString(16);

  var zoomTemp=”00″+zoom.toString();

  var picRowTemp=”00000000″+picRow.toString();

  var picColTemp=”00000000″+picCol.toString();

  zoom=”L”+zoomTemp.substring(zoom.length,zoom.length+2);

  picRow=”R”+picRowTemp.substring(picRow.length,picRow.length+8);

  picCol=”C”+picColTemp.substring(picCol.length,picCol.length+8);

  path=this.url+”+zoom+”/”+picRow+”/”+picCol+”.jpg”;

  //alert(path);

  return path;

      },  //end function

2.google瓦片的geturl方法：

getURL: function(bounds){

  var x = Math.round(Math.pow(2,this.map.getZoom())*(bounds.left+180)/360);   

        x = Math.round(x);   

        var y = Math.round(Math.pow(2,this.map.getZoom()-1)*(90-bounds.top)/180+Math.pow(2,this.map.getZoom()-2));   

        var z = this.map.getZoom(); 

        return “../../googleMap/m_”+z+”_”+x+”_”+y+”.png”;  

  

    },

3.天地图瓦片的geturl方法：

getURL: function(bounds){

     var lon1=bounds.left;

     var lat1=bounds.top;

     var lon2=bounds.right;

     var lat2=bounds.bottom;

        var picHeight=256;    //图片大小 

        var picResolution,picRow,picCol;   //分辨率,所求图片行号,列号

        var tileOriginX,tileOriginY;    //切图原点

        var iResolution = this.map.getResolution();

        var temp1=new Array();

        var i,zoom=0,path;    //zoom代表缩放级别；

       

         tileOriginX=-180;

         tileOriginY=90;

       //计算zoom

       zoom=this.map.getZoom();

       //计算行列号(使用瓦片的中心点经纬度计算)

       picRow=Math.ceil(Math.abs((tileOriginY-(lat1+lat2)/2)/(iResolution*picHeight)))-1;

       picCol=Math.ceil(Math.abs((tileOriginX-(lon1+lon2)/2)/(iResolution*picHeight)))-1; 

       path=”../../china/”+zoom+”/”+picRow+”/”+picCol+”.png”

       //alert(path);

       return path;

      },  //end function

转载自：https://blog.csdn.net/yihui1314/article/details/77601199