/**
* 对自定义规则切割的图片进行拼装的类
*/
OpenLayers.Layer.SoGou = OpenLayers.Class(OpenLayers.Layer.TileCache, {initialize: function (name, url, options) {var tempoptions = OpenLayers.Util.extend({'format': 'image/png',isBaseLayer: true}, options);OpenLayers.Layer.TileCache.prototype.initialize.apply(this, [name, url, {},tempoptions]);this.extension = this.format.split('/')[1].toLowerCase();this.extension = (this.extension == 'jpg') ? 'jpeg' : this.extension;this.transitionEffect = "resize";this.buffer = 0;},/*** 按地图引擎切图规则实现的拼接方式*/getURL: function (bounds) {var tilez=this.map.zoom-1;var offsetX = Math.pow(2,tilez); var offsetY = offsetX - 1; var res = this.map.getResolution();var bbox = this.map.getMaxExtent();var size = this.tileSize;var bx = Math.round((bounds.left - bbox.left) / (res * size.w));var by = Math.round((bbox.top - bounds.top) / (res * size.h));var numX = bx - offsetX; var numY = (-by) + offsetY; tilez = tilez + 1; var zoomLevel = 729 - tilez;if (zoomLevel == 710) zoomLevel = 792;var blo = Math.floor(numX / 200); var bla = Math.floor(numY / 200); var blos,blas; if (blo < 0)  blos = "M" + ( - blo); else blos = "" + blo; if (bla < 0)  blas = "M" + ( - bla); else blas = "" + bla; var x = numX.toString().replace("-","M");  var y = numY.toString().replace("-","M"); var urlsNum = parseInt((bx + by) % this.url.length); var strURL = ""; strURL = this.url[urlsNum] + zoomLevel + "/" + blos + "/" + blas + "/" + x + "_" + y + ".GIF";return strURL;},clone: function (obj) {if (obj == null) {obj = new OpenLayers.Layer.SoGou(this.name, this.url, this.options);}obj = OpenLayers.Layer.TileCache.prototype.clone.apply(this, [obj]);return obj;},CLASS_NAME: "OpenLayers.Layer.SoGou"
});