hi-ucs/front/public/leaflet/libs/iclient8c/examples/js/layer/WebGLLayer.js

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/* COPYRIGHT 2012 SUPERMAP
* 本程序只能在有效的授权许可下使用。
* 未经许可,不得以任何手段擅自使用或传播。*/
/**
* Class: SuperMap.Layer.WebGLLayer
* 使用webgl方式进行渲染的图层
* 使用此图层依赖了部分矩阵计算所以需要引用examples/js/glMatrix-0.9.5.min.js库
* Inherits from:
* - <SuperMap.Layer.Grid>
*/
SuperMap.Layer.WebGLLayer = SuperMap.Class(SuperMap.Layer.Grid, {
/**
* Constant: DEFAULT_PARAMS
* {Object} 设置到瓦片url请求上的参数的默认值。
* transparent图层是否透明,默认为false
* 和cacheEnabled是否使用服务端的缓存默认为true
*/
DEFAULT_PARAMS: {
//maxVisibleVertex: 360000,
transparent: false,
cacheEnabled: true
},
/**
* Property: prjStr
* {String}
* 投影键值串在图层初始化完成时赋值。例如prjCoordSys={"epsgCode":3857}
* 内部使用,不公开
*/
prjStr1: null,
/**
* Property: getmapstatusservice
* {String}
*/
getMapStatusService: null,
/**
* Property: viewBounds
* {Object} 地图窗口显示区域的范围。
*/
viewBounds: null,
/**
* Property: viewer
* {Object} 用户显示视窗。
*/
viewer: null,
/**
* Property: scale
* {Number} 地图的显示比例尺。
*/
scale: null,
/**
* Property: overlapDisplayed
* {Boolean} 地图对象在同一范围内时是否重叠显示默认为true。
*/
overlapDisplayed: true,
/**
* Property: redirect
* {Boolean} 是否重定向HTTP 传输中的一个概念。如果为 true则将请求重定向到图片的真实地址
* 如果为 false则响应体中是图片的字节流。默认为 false不进行重定向。
*/
redirect: false,
/**
* Property: overlapDisplayedOptions
* {<SuperMap.REST.OverlapDisplayedOptions>} 避免地图对象压盖显示的过滤选项,
* 当 overlapDisplayed为 false 时有效,用来增强对地图对象压盖时的处理。
*/
overlapDisplayedOptions: null,
/**
* Property: useCanvas
* {Boolean} 设置是否将一个图层用Canvas元素显示默认为true只能为true
*
*/
useCanvas: true,
/**
* Property: canvas
* 当useCanvas为true时此Canvas作为所有瓦片的现实容器。
*/
canvas: null,
/**
* Property: canvasContext
* {Canvas} WEBGL的上下文。
*/
canvasContext: null,
/**
* Property: lastResolution
* canvas最后一次绘制的分辨率。
*/
lastResolution: null,
/**
* Property: lastCanvasPosition
* canvas最后一次绘制时距左上角的位置。
*/
lastCanvasPosition: null,
/**
* Property: redrawCanvas
* Indicates if the canvas element should be reset before
* the next tile is drawn.
* 表明canvas元素是否需要在绘制之前重置默认为false。
*/
redrawCanvas: false,
/**
* Property: format
* {String} 地图服务的图片格式。
* 默认值为 png ,目前支持 png、jpg、bmp、gif。
*/
format: "png",
/**
* Property: dpi
* {Float} 屏幕上每英寸包含像素点的个数。
* 该参数结合图层比例尺可以推算出该比例尺下图层的分辨率。
*/
dpi: null,
/**
* Property: isBaseLayer
* {Boolean} 图层是否为底图默认为true。
*/
isBaseLayer: true,
/**
* Property: tileOriginCorner
* {String} 网格的原点位置。(当<tileOrigin>属性未被设置时,此属性有效)。
* 可选的值包括"tl" (左上), "tr" (右上), "bl" (左下), and "br"(右下) 默认为 "tl"。
*/
tileOriginCorner: "tl",
/**
* Property: datumAxis
* {Number} 地理坐标系统椭球体长半轴。用户自定义地图的Options时若未指定该参数的值
* 则DPI默认按照WGS84参考系的椭球体长半轴6378137来计算。
*/
datumAxis: null,
/**
* Property: timeoutID
* {Number} 记录setTimeout的索引值。
*/
timeoutID :null,
/**
* Property: memoryImg
* {Object} 存放已经加载的图片作为缓存。
* 在每次图层状态改变时需要重绘,就会首先读取此缓存内部是否已经存在此图片,
* 如果存在直接取出进行绘制,不存在再向服务器发送请求。
* 这样可以提高效率,并且在断网状态下也可以查看缓存的图片。
*/
memoryImg: null,
/**
* Property: memoryKeys
* {Array} 保存已经缓存图片的key值。
* 每一张图片有对应一个key如x0y1z2
* 代表缩放级别为2下的第一横排第二竖排的图片从左上角开始计算.
*/
memoryKeys:[],
/**
* APIProperty: bufferImgCount
* {Number} 用来记录内存中缓存图片的数量,默认值为 1000。
* 为了减少网络访问量,在使用 Canvas 模式时,图层会将访问过的图片保存在内存中,
* 如果访问的图片数量超过该属性定义的值,那么新访问的图片会替换已经缓存的图片。
*/
bufferImgCount:1000,
/**
* Property: isFirstLoad
* {Bool} 记录是否第一次加载默认为true。
*/
isFirstLoad: true,
/**
* Property: zoomDuration
* {Number} 设置两次滚轮事件触发的间隔如果两次滚轮触发时间差小于500ms。
* 则放弃前一次滚轮事件。(设置此属性的同时设置<SuperMap.Handler.MouseWheel>的interval属性会产生错误
*/
zoomDuration:500,
/**
* Property: isZoomming
* {bool} 记录是否在缩放。
*/
isZoomming: null,
/**
* Property: useHighSpeed
* {bool} 记录是否采用高速读图策略。
*/
useHighSpeed:true,
/**
* Property: changeDx
* {Interger} 记录位置的改变量。
*/
changeDx: null,
/**
* Property: changeDy
* {Interger} 记录位置的改变量。
*/
changeDy: null,
/**
* Property: lenColumn
* {Interger} 记录当前grid的col长度。
*/
lenColumn: null,
/**
* Property: lenRow
* {Interger} 记录当前grid的row长度。
*/
lenRow: null,
/**
* Porperty: sdcardPath
* {String} 记录手机当前SDCard位置。
*/
sdcardPath:null,
/**
* Porperty: storageType
* {String} 离线存储类型为文件格式。
*/
storageType:"File",
/**
* Porperty: transitionObj
* {Object} 缩放动画对象。
*/
transitionObj: null,
/**
* Property: inZoom
* {Boolean} 当前地图操作是否在缩放过程中。
*/
inZoom: false,
/**
* Constructor: SuperMap.Layer.WebGLLayer
* 使用webgl方式进行渲染的图层
*
* Parameters:
* name - {String} 图层名称。
* url - {String} 图层的服务地址。
* params - {Object} 设置到url上的可选参数。
* options - {Object} 附加到图层属性上的可选项,父类与此类开放的属性。
*/
initialize: function (name, url, params, options) {
//通过浏览器获取部分信息
var me = this, broz = SuperMap.Browser;
//me.tileSize = new SuperMap.Size(256, 256);
//判断是否为移动端如果是那么设置缓存图片上限为500比电脑上少了一半考虑到手持端内存
if(!!SuperMap.isApp)me.bufferImgCount = 500;
SuperMap.Layer.Grid.prototype.initialize.apply(me, arguments);
//reports the progress of a tile filter
if(me.useCanvas) {
//通过浏览器的判定决定是否支持Canvas绘制
me.useCanvas = SuperMap.Util.supportCanvas();
}
//如果为android手持端那么不能支持Canvas绘制
if(broz.device === 'android') {
me.useCanvas = false;
}
if (SuperMap.isApp) {
//me.sdcardPath = "file://" + window.plugins.localstoragemanager.getsdcard().sdcard + "/";
cordova.exec(function(obj){
me.sdcardPath = "file://" + obj.sdcard + "/";
}, function(e){}, "LocalStoragePlugin","getsdcard", []);
me.useCanvas = true;
}
if(me.useCanvas) {
me.canvas = document.createElement("canvas");
me.canvas.id = "Canvas_" + me.id;
me.canvas.style.position = "absolute";
me.div.appendChild(me.canvas);
me.canvasContext = me.canvas.getContext('experimental-webgl');
me.transitionObj = new SuperMap.Animal(me);
me.memoryImg = {};
}
//如果是Canvas策略采用高速出图 。
me.useHighSpeed = me.useCanvas ? true : false;
me.isFirstLoad = true;
//子类的代码
SuperMap.Util.applyDefaults(me.params, me.DEFAULT_PARAMS);
me.events.addEventType("layerInitialized");
me.events.addEventType("loadError");
if (me.params.transparent) {
if (me.format === "jpg") {
me.format = SuperMap.Util.alphaHack() ? "gif" : "png";
}
if (me.format === "bmp") {
me.format = SuperMap.Util.alphaHack() ? "bmp" : "png";
}
}
if (typeof me.params.clipRegion !== "undefined") {
if (me.params.clipRegion instanceof SuperMap.Geometry) {
me.params.clipRegionEnabled = true;
var sg = SuperMap.REST.ServerGeometry.fromGeometry(me.params.clipRegion);
me.params.clipRegion = SuperMap.Util.toJSON(sg);
} else {
delete me.params.clipRegion;
}
}
if (typeof me.params.layersID !== "undefined") {
if (!me.params.layersID){
delete me.params.layersID;
}
}
if (me.params.redirect) {
me.redirect = true;
}
//用户传Layer的地图单位
if(me.units){
me.units = me.units.toLowerCase();
}
if(me.dpi && me.maxExtent &&(me.resolutions || me.scales)) {
//如果设置了dpi、maxExtent、resolutions或者是scales,则不需要向服务端发出请求获取图层信息
}else if(!me.dpi && (!me.viewBounds || !me.viewer || !me.scale)) {
//当在options中设置viewBounds 、viewer 、scale 、units 、datumAxis则计算dpi
if (!!SuperMap.isApp) {
var layerContext = {
tile:me
};
cordova.exec(function(layerContext){
return function(r){
layerContext.tile.getAppStatusSucceed(layerContext,r);
}
}(layerContext), function(e){},
"LocalStoragePlugin","getconfig",
[this.name,this.storageType]
);
} else{
var strServiceUrl = me.url;
if (SuperMap.Util.isArray(url)) {
strServiceUrl = url[0];
}
var getMapStatusService = new SuperMap.REST.MapService(strServiceUrl,
{eventListeners: {processCompleted: me.getStatusSucceed, scope: me,
processFailed: me.getStatusFailed}, projection: me.projection});
getMapStatusService.processAsync();
}
}
if (me.projection) {
if(typeof me.projection == "string") {
me.projection = new SuperMap.Projection(me.projection);
}
var arr = me.projection.getCode().split(":");
if (arr instanceof Array && arr.length == 2) {
me.prjStr1 = "{\"epsgCode\":" + arr[1] + "}";
}
}
},
getAppStatusSucceed:function(layerContext,r) {
var mapStatus = r.json;
var me = this;
if (mapStatus != "false")
{
mapStatus = eval('(' + mapStatus + ')');
var bounds = mapStatus.bounds;
bounds = new SuperMap.Bounds(bounds.left,bounds.bottom,bounds.right,bounds.top);
me.maxExtent = bounds;
if(mapStatus.dpi){
me.dpi = mapStatus.dpi;
me.options.scales = mapStatus.scales;
me.units = mapStatus.unit;
me.datumAxis = 6378137;
}
else{
var viewBounds = mapStatus.viewBounds,
coordUnit = mapStatus.coordUnit,
viewer = mapStatus.viewer,
scale = mapStatus.scale,
datumAxis = mapStatus.datumAxis;
//将jsonObject转化为SuperMap.Bounds用于计算dpi。
viewBounds = new SuperMap.Bounds(viewBounds.left,viewBounds.bottom,viewBounds.right,viewBounds.top);
me.viewBounds = viewBounds;
viewer = new SuperMap.Size(viewer.rightBottom.x, viewer.rightBottom.y);
me.viewer = viewer;
me.scale = scale;
coordUnit = coordUnit.toLowerCase();
me.units = me.units || coordUnit;
me.datumAxis = datumAxis;
me.dpi = SuperMap.Util.calculateDpi(viewBounds, viewer, scale, me.units, datumAxis);
}
me.events.triggerEvent('layerInitialized',me);
}else{
var strServiceUrl = me.url;
if (SuperMap.Util.isArray(me.url)) {
strServiceUrl = me.url[0];
}
var getMapStatusService = new SuperMap.REST.MapService(strServiceUrl,
{eventListeners:{processCompleted: me.getStatusSucceed, scope: me,
processFailed: me.getStatusFailed}, projection: me.projection});
getMapStatusService.processAsync();
}
},
/**
* Method: setMapStatus
* 计算Dpi设置maxExtent。
*/
getStatusSucceed: function(mapStatus) {
var me = this;
if (mapStatus.result){
// 当用户未设置scalesvisibleScales存在值、visibleScalesEnable为true时,使layer.scales=visibleScales。
var visScales = null;
var orResult = mapStatus.originResult;
if(orResult){
visScales = orResult.visibleScales;
if(!me.scales && orResult.visibleScalesEnabled && (visScales &&visScales.length&&visScales.length>0))
{
this.options.scales=visScales;
}
}
var mapStatus = mapStatus.result;
var bounds = mapStatus.bounds, viewBounds = mapStatus.viewBounds,
coordUnit = mapStatus.coordUnit,
viewer = mapStatus.viewer,
scale = mapStatus.scale,
datumAxis = mapStatus.datumAxis;
//将jsonObject转化为SuperMap.Bounds用于计算dpi。
viewBounds = new SuperMap.Bounds(viewBounds.left,viewBounds.bottom,viewBounds.right,viewBounds.top);
me.viewBounds = viewBounds;
viewer = new SuperMap.Size(viewer.rightBottom.x, viewer.rightBottom.y);
me.viewer = viewer;
me.scale = scale;
bounds = new SuperMap.Bounds(bounds.left,bounds.bottom,bounds.right,bounds.top);
me.maxExtent = bounds;
coordUnit = coordUnit.toLowerCase();
me.units = me.units || coordUnit;
me.datumAxis = datumAxis;
me.dpi = SuperMap.Util.calculateDpi(viewBounds, viewer, scale, me.units, datumAxis);
if (!!SuperMap.isApp){
//window.plugins.localstoragemanager.savaconfig(this.name,mapStatus);
cordova.exec(function(){}, function(e){}, "LocalStoragePlugin","savaconfig", [this.name,mapStatus]);
}
me.events.triggerEvent('layerInitialized',me);
}
},
/**
* Method: getStatusFailed
* 获取图层状态失败
*/
getStatusFailed: function(failedMessage) {
var me = this;
me.events.triggerEvent('loadError',failedMessage);
},
/**
* Method: getTileUrl
* 获取瓦片的URL。
*
* Parameters:
* xyz - {Object} 一组键值对表示瓦片X, Y, Z方向上的索引。
*
* Returns
* {String} 瓦片的 URL 。
*/
getTileUrl: function (xyz) {
var me = this,
newParams,
tileSize = me.tileSize,
scale = me.scales[xyz.z];
//在没有设置任何投影的情况下比例尺可能大于1为了提高容错能力注释掉比例尺矫正函数。 maoshuyu
//scale = SuperMap.Util.normalizeScale(scale);
if(!scale)scale = this.getScaleForZoom(xyz.z);
newParams = {
"width" : tileSize.w,
"height" : tileSize.h,
"x" : xyz.x,
"y" : xyz.y,
"scale" : scale,
//hansj忽略后面的注释//由于服务器关于缓存有问题所以redirect先设为false。
"redirect" : me.redirect
};
if (SuperMap.Credential.CREDENTIAL) {
newParams[SuperMap.Credential.CREDENTIAL.name] = SuperMap.Credential.CREDENTIAL.getValue();
}
if (!me.params.cacheEnabled) {
newParams.t = new Date().getTime();
}
if (typeof me.params.layersID !== "undefined" && typeof newParams.layersID == "undefined") {
if (me.params.layersID && me.params.layersID.length > 0){
newParams.layersID = me.params.layersID;
}
}
if (me.prjStr1) {
newParams.prjCoordSys = me.prjStr1;
}
return me.getFullRequestString(newParams);
},
/**
* Method: getFullRequestString
* 将参数与URL合并获取完整的请求地址。重写基类方法
*
* Parameters:
* newParams - {Object}
* altUrl - {String}
*
* Returns:
* {String}
*/
getFullRequestString:function(newParams, altUrl) {
var me = this,
url = altUrl || this.url,
allParams, paramsString, urlParams;
allParams = SuperMap.Util.extend({}, me.params),
allParams = SuperMap.Util.extend(allParams, newParams);
if(allParams.overlapDisplayed === false) {
me.overlapDisplayedOptions = allParams.overlapDisplayedOptions;
me.overlapDisplayed = allParams.overlapDisplayed;
delete allParams.overlapDisplayed;
delete allParams.overlapDisplayedOptions;
}
paramsString = SuperMap.Util.getParameterString(allParams);
if (SuperMap.Util.isArray(url)) {
var s = "" + newParams.x + newParams.y;
url = me.selectUrl(s, url);
}
url = url + "/tileImage." + me.format;
urlParams = SuperMap.Util.upperCaseObject(SuperMap.Util.getParameters(url));
for (var key in allParams) {
if(key.toUpperCase() in urlParams) {
delete allParams[key];
}
}
paramsString = SuperMap.Util.getParameterString(allParams);
if( me.tileOrigin ){
paramsString = paramsString + "&origin={\"x\":" + me.tileOrigin.lon + "," + "\"y\":" + me.tileOrigin.lat + "}";
}
if(me.overlapDisplayed === false) {
me.overlapDisplayedOptions = me.overlapDisplayedOptions ? me.overlapDisplayedOptions : new SuperMap.REST.OverlapDisplayedOptions();
paramsString += "&overlapDisplayed=false&overlapDisplayedOptions="+ me.overlapDisplayedOptions.toString();
}
return SuperMap.Util.urlAppend(url, paramsString);
},
/**
* Method: mergeNewParams
* 动态修改URL的参数。(重写基类方法)
*
* Parameters:
* newParams - {Object}
*
* Returns
* {Boolean} 修改是否成功。
*/
mergeNewParams: function (newParams) {
if (typeof (newParams.clipRegion) != "undefined") {
if (newParams.clipRegion instanceof SuperMap.Geometry) {
newParams.clipRegionEnabled = true;
var sg = SuperMap.REST.ServerGeometry.fromGeometry(newParams.clipRegion);
newParams.clipRegion = SuperMap.Util.toJSON(sg);
} else {
delete newParams.clipRegion;
}
}
return SuperMap.Layer.HTTPRequest.prototype.mergeNewParams.apply(this, [newParams]);
},
/**
* Method: removeMap
* rewrite Grid.removeMap method to clear '_timeoutId'
* Called when the layer is removed from the map.
*
* Parameters:
* map - {<SuperMap.Map>} The map.
*/
removeMap: function(map) {
SuperMap.Layer.Grid.prototype.removeMap.apply(this, [map])
this._timeoutId && window.clearTimeout(this._timeoutId);
this._timeoutId = null;
},
/**
* APIMethod: destroy
* 解构Layer类释放资源。
*/
destroy: function () {
var me = this;
if(me.getMapStatusService) {
me.getMapStatusService.events.listeners = null;
me.getMapStatusService.destroy();
}
me.viewBounds = null;
me.viewer = null;
me.scale = null;
SuperMap.Layer.Grid.prototype.destroy.apply(me, arguments);
me.format = null;
me.dpi = null;
me.datumAxis = null;
me.isBaseLayer = null;
me.tileOriginCorner = null;
me.tileSize = null;
me.bufferContext = null;
if(me.transitionObj){
me.transitionObj.destroy();
me.trnasitionObj = null;
}
if (me.useCanvas) {
me.canvas = null;
me.memoryImg = null;
}
me.DEFAULT_PARAMS = null;
},
/**
* APIMethod: clone
* 创建当前图层的副本。
*
* Parameters:
* obj - {Object}
*
* Returns:
* {<SuperMap.SuperMap.Layer>} 新创建的图层
*/
clone: function (obj) {
var me = this;
if (obj == null) {
obj = new SuperMap.Layer.WebGLLayer(
me.name, me.url, me.params, me.getOptions());
}
obj = SuperMap.Layer.Grid.prototype.clone.apply(me, [obj]);
obj._timeoutId = null;
return obj;
},
/**
* Method: moveTo
* 当map移动时出发此事件. 所有的瓦片移动操作实际是
* 由map完成, moveTo's 的任务是接受一个bounds并且确定
* 此bounds下的所请求的图片是否被预加载。
*
* Parameters:
* bounds - {<SuperMap.Bounds>}
* zoomChanged - {Boolean}
* dragging - {Boolean}
*/
moveTo: function(bounds, zoomChanged, dragging) {
var me = this,
ratio = this.lastResolution / this.map.getResolution(),
style = this.map.layerContainerDiv.style,
left = parseInt(style.left),
top = parseInt(style.top);
this.inZoom = zoomChanged ? true: false;
this.changeDx = -left;
this.changeDy = -top;
//如果是缩放出发的moveto不进行fixposition。
//当在缩放时进行平移不能触发fixPosition(),因为
//新图没有读出来,会出图错误。
if(!zoomChanged && !me.isZoomming && me.useCanvas){
this.fixPosition();
}
SuperMap.Layer.HTTPRequest.prototype.moveTo.apply(me, arguments);
bounds = bounds || me.map.getExtent();
// 当操作为移动时候并不重绘整个canvas
me.redrawCanvas = zoomChanged;
me.dragging = dragging;
// the new map resolution
var resolution = this.map.getResolution();
// 当一切缩放属性都添加完后才能进行缩放动画。
if (me.useCanvas && ratio!=1) {
if (!zoomChanged || dragging || (this.lastResolution === null) || (this.lastCanvasPosition === null)) {
} else {
var lefttop = this.getLayerPxFromLonLat(this.lastCanvasPosition);
if(!this.map.isIEMultipTouch){
// this.transitionObj.begin(this.canvas, lefttop);
}
}
}
if (bounds != null) {
// 当grid为空或是进行缩放必须重绘整个canvas
var forceReTile = !me.grid.length || zoomChanged;
// 获取所有tiles的bounds
var tilesBounds = me.getTilesBounds();
if (this.singleTile) {
if ( forceReTile ||
(!dragging && !tilesBounds.containsBounds(bounds))) {
if(zoomChanged && this.transitionEffect !== 'resize') {
this.removeBackBuffer();
}
if(!zoomChanged || this.transitionEffect === 'resize') {
this.applyBackBuffer(resolution);
}
this.initSingleTile(bounds);
}
} else {
if (forceReTile || !tilesBounds.containsBounds(bounds, true)) {
if(this.useCanvas){
//判断是否第一次加载
if(this.isFirstLoad){
this.redrawCanvas = true;
this.inZoom = true;
this.isFirstLoad = false;
}
}
if(this.zoomDuration && me.useCanvas) {
this.resetCanvas();
this.isZoomming = true;
window.clearTimeout(this._timeoutId);
this._timeoutId = window.setTimeout(
SuperMap.Function.bind(function(){
this.initGriddedTiles(bounds);
}, this),
this.zoomDuration
);
} else {
if(zoomChanged && this.transitionEffect === 'resize') {
this.applyBackBuffer(resolution);
}
this.initGriddedTiles(bounds);
}
} else {
this.scheduleMoveGriddedTiles();
}
}
}
//通过改变量计算缩放前canvas左上角的地理位置。
if (me.useCanvas){
//获取改变量的位置。
var canvasPosition = new SuperMap.Pixel(this.changeDx, this.changeDy);
//通过改变量计算canvas的地理位置。
this.lastCanvasPosition = this.map.getLonLatFromLayerPx(canvasPosition);
}
},
/**
* Method: scheduleMoveGriddedTiles
* 将移动tile加入计划当中去。
*/
scheduleMoveGriddedTiles: function() {
if(this.useHighSpeed){
this.moveGriddedTiles();
}else{
this.timerId && window.clearTimeout(this.timerId);
this.timerId = window.setTimeout(
this._moveGriddedTiles,
this.tileLoadingDelay
);
}
},
/**
* Method: moveGriddedTiles
*/
moveGriddedTiles: function() {
var shifted = true;
var buffer = this.buffer || 1;
var tlLayer = this.grid[0][0].position;
var offsetX = -this.changeDx;
var offsetY = -this.changeDy;
var tlViewPort = tlLayer.add(offsetX, offsetY);
if (tlViewPort.x > -this.tileSize.w * (buffer - 1)) {
this.shiftColumn(true);
} else if (tlViewPort.x < -this.tileSize.w * buffer) {
this.shiftColumn(false);
} else if (tlViewPort.y > -this.tileSize.h * (buffer - 1)) {
this.shiftRow(true);
} else if (tlViewPort.y < -this.tileSize.h * buffer) {
this.shiftRow(false);
} else {
shifted = false;
}
if (shifted) {
if(this.useHighSpeed){
this.moveGriddedTiles();
}else{
this.timerId = window.setTimeout(this._moveGriddedTiles, 0);
}
} else {
//tiles have shifted alreadyso we can do something.
//e.g. We can draw images in those tiles on a canvas, if no image is contained in tile,
//we draw nothing.
}
},
/**
* Method: moveByPx
* 重写父类方法。
*/
moveByPx: function(dx, dy) {
this._timeoutId && window.clearTimeout(this._timeoutId);
//记录每次的改变量。
this.changeDx +=dx;
this.changeDy +=dy;
if(this.useHighSpeed){
this.fixPosition();
this.scheduleMoveGriddedTiles();
}
},
/**
* Method: fixPosition
* 平移逻辑。
*/
fixPosition: function(){
var tile, tileImg, i, j,
me = this;
//清空webgl
me.canvasContext.viewport(0, 0, me.canvasContext.viewportWidth, me.canvasContext.viewportHeight);
// me.canvasContext.clear(me.canvasContext.COLOR_BUFFER_BIT | me.canvasContext.DEPTH_BUFFER_BIT);
for(i=0; i<this.lenRow; i++){
for(j=0; j<this.lenColumn; j++){
tile = me.grid[i][j];
tileImg = tile.lastImage;
//firefox即使图片加载失败complete属性依然为true故用width和height判断
//IE图片加载失败时width为28height为30故用complete判断
if((tileImg != null) && (tile.shouldDraw === true) &&
(tileImg.width > 0 && tileImg.height > 0) &&
tileImg.complete){
var positionX = tile.position.x - me.changeDx;
var positionY = tile.position.y - me.changeDy;
if(tile.lastImage.firstInView){
if(me.getExtent().containsLonLat(tile.bounds.getCenterLonLat())){
tile.lastImage.firstInView = false;
}
else if(me.getExtent().intersectsBounds(tile.bounds)){
tile.setFirstInView();
}
}
me.drawCanvasTile2(tile.lastImage, positionX, positionY, false);
}
}
}
},
/**
* Method: addTile
* Gives subclasses of Grid the opportunity to create an
* OpenLayer.Tile of their choosing. The implementer should initialize
* the new tile and take whatever steps necessary to display it.
*
* Parameters
* bounds - {<SuperMap.Bounds>}
* position - {<SuperMap.Pixel>}
*
* Returns:
* {<SuperMap.Tile>} The added SuperMap.Tile
*/
addTile: function(bounds,position) {
// 修改Tile类 todo
if(this.useCanvas){
return new SuperMap.Tile.WebGLImage(this, position, bounds, null, this.tileSize, this.useCanvas)
}else{
var tile = new this.tileClass(
this, position, bounds, null, this.tileSize, this.tileOptions
);
this.events.triggerEvent("addtile", {tile: tile});
return tile;
}
},
/**
* Method: drawCanvasTile
* 当Image加载完成后将image显示到canvas上。
*
* Parameters:
* image - {<Image>} The tile to draw
* position - {<SuperMap.Pixel>} The position of the tile.
*/
drawCanvasTile: function(image, position) {
if (this.dragging) {
return;
}
if(this.inZoom){
image.firstInView = false;
}
this.resetCanvas();
var mapStyle = this.map.layerContainerDiv.style;
var left = parseInt(mapStyle.left),
top = parseInt(mapStyle.top);
//解决ie||移动设备下canvas绘图出错。
if(SuperMap.Browser.name === 'msie'){
var context = {
layer: this,
position: position,
image: image,
mapStyle: mapStyle
};
var _drawCanvasIE = SuperMap.Function.bind(this.drawCanvasIE, context);
window.setTimeout(_drawCanvasIE,100);
}else{
//通过position来绘制图片解决白线问题
this.drawCanvasTile2(image, position.x + left, position.y + top);
}
},
/**
* Method: drawImgData
* canvas上绘制imgdata字符串
*
* Parameters:
* imgData - {<String>} imgdata字符串
* p - {<SuperMap.Pixel>} tile的位置.
*/
drawImgData:function(imgData,p){
var mapStyle = this.map.layerContainerDiv.style;
var left = parseInt(mapStyle.left),
top = parseInt(mapStyle.top);
// this.canvasContext.putImageData(imgData, p.x+left, p.y+top);
},
//在ie/移动设备下解决连续绘canvas出错而设置的函数。
drawCanvasIE:function(){
this.layer.drawCanvasTile2(this.image, this.position.x + parseInt(this.mapStyle.left), this.position.y + parseInt(this.mapStyle.top));
},
shaderProgram:null,
/**
* Method: drawCanvasTile2
* 将image显示到canvas上。
*
* Parameters:
* image - {<Image>} 要绘制的图块对象
* positionX - {Number} tile在canvas中的x坐标
* positionY - {Number} tile在canvas中的y坐标
* clear - {boolean} 是否需要重新清除。
*/
drawCanvasTile2: function(image, positionX, positionY, clear){
clear = clear || true;
if(image){
var gl = this.canvasContext;
var shaderProgram;
if(true)
{
//初始化渲染器
var fragmentShader = this.getShader(gl, "fragment");
var vertexShader = this.getShader(gl, "vertex");
shaderProgram = gl.createProgram();
gl.attachShader(shaderProgram, vertexShader);
gl.attachShader(shaderProgram, fragmentShader);
gl.linkProgram(shaderProgram);
if (!gl.getProgramParameter(shaderProgram, gl.LINK_STATUS)) {
alert("Could not initialise shaders");
}
gl.useProgram(shaderProgram);
shaderProgram.vertexPositionAttribute = gl.getAttribLocation(shaderProgram, "aVertexPosition");
gl.enableVertexAttribArray(shaderProgram.vertexPositionAttribute);
shaderProgram.textureCoordAttribute = gl.getAttribLocation(shaderProgram, "aTextureCoord");
gl.enableVertexAttribArray(shaderProgram.textureCoordAttribute);
shaderProgram.pMatrixUniform = gl.getUniformLocation(shaderProgram, "uPMatrix");
shaderProgram.mvMatrixUniform = gl.getUniformLocation(shaderProgram, "uMVMatrix");
shaderProgram.samplerUniform = gl.getUniformLocation(shaderProgram, "uSampler");
}
//计算瓦片位置
var cubeVertexPositionBuffer00 = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer00);
var w = gl.viewportWidth;
var h = gl.viewportHeight;
var nScale;
if(w >= h)
{
nScale = this.tileSize.h/h;
}
else
{
nScale = this.tileSize.h/w;
}
//定义256*256的矩形在当前视图中的矩阵
var vertices = [
-1*nScale, -1*nScale, 0,
1*nScale, -1*nScale, 0,
1*nScale, 1*nScale, 0,
-1*nScale, 1*nScale, 0
];
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(vertices), gl.STATIC_DRAW);
cubeVertexPositionBuffer00.itemSize = 3;
cubeVertexPositionBuffer00.numItems = 4;
var cubeVertexTextureCoordBuffer00 = gl.createBuffer();
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexTextureCoordBuffer00);
var textureCoords = [
0.0, 0.0,
1.0, 0.0,
1.0, 1.0,
0.0, 1.0
];
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(textureCoords), gl.STATIC_DRAW);
cubeVertexTextureCoordBuffer00.itemSize = 2;
cubeVertexTextureCoordBuffer00.numItems = 4;
var cubeVertexIndexBuffer00 = gl.createBuffer();
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer00);
var cubeVertexIndices = [
0, 1, 2, 0, 2, 3
];
gl.bufferData(gl.ELEMENT_ARRAY_BUFFER, new Uint16Array(cubeVertexIndices), gl.STATIC_DRAW);
cubeVertexIndexBuffer00.itemSize = 1;
cubeVertexIndexBuffer00.numItems = 6;
//加入图片
var texture = gl.createTexture();
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.pixelStorei(gl.UNPACK_FLIP_Y_WEBGL, true);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.NEAREST);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.NEAREST);
gl.bindTexture(gl.TEXTURE_2D, null);
gl.viewport(0, 0, gl.viewportWidth, gl.viewportHeight);
var pMatrix = mat4.create();
var mvMatrix = mat4.create();
mat4.perspective(90, gl.viewportWidth / gl.viewportHeight, 1, 100.0, pMatrix);
mat4.identity(mvMatrix);
//进行平移
var x = (positionX - w/2 )*2*nScale/this.tileSize.h + nScale;
var y = (h/2 - positionY)*2*nScale/this.tileSize.h - nScale;
mat4.translate(mvMatrix, [x, y, -1.0]);
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexPositionBuffer00);
gl.vertexAttribPointer(shaderProgram.vertexPositionAttribute, cubeVertexPositionBuffer00.itemSize, gl.FLOAT, false, 0, 0);
gl.bindBuffer(gl.ARRAY_BUFFER, cubeVertexTextureCoordBuffer00);
gl.vertexAttribPointer(shaderProgram.textureCoordAttribute, cubeVertexTextureCoordBuffer00.itemSize, gl.FLOAT, false, 0, 0);
gl.activeTexture(gl.TEXTURE0);
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.uniform1i(shaderProgram.samplerUniform, 0);
gl.bindBuffer(gl.ELEMENT_ARRAY_BUFFER, cubeVertexIndexBuffer00);
gl.uniformMatrix4fv(shaderProgram.pMatrixUniform, false, pMatrix);
gl.uniformMatrix4fv(shaderProgram.mvMatrixUniform, false, mvMatrix);
gl.drawElements(gl.TRIANGLES, cubeVertexIndexBuffer00.numItems, gl.UNSIGNED_SHORT, 0);
}
},
/**
* Method: getShader
* 初始化着色器
*
* Parameters:
* gl - {<WebGLRenderingContext>} webgl上下文
* name - {String} 可以为片元着色器“fragment”或顶点着色器“vertex”
*/
getShader:function(gl,name){
var shader;
var str = "";
if(name == "fragment" )
{
shader = gl.createShader(gl.FRAGMENT_SHADER);
str = "precision mediump float; varying vec2 vTextureCoord; uniform sampler2D uSampler;void main(void){gl_FragColor = texture2D(uSampler, vec2(vTextureCoord.s, vTextureCoord.t));}";
}
else if(name == "vertex" )
{
shader = gl.createShader(gl.VERTEX_SHADER);
str = "attribute vec3 aVertexPosition; attribute vec2 aTextureCoord; uniform mat4 uMVMatrix; uniform mat4 uPMatrix; varying vec2 vTextureCoord; void main(void) { gl_Position = uPMatrix * uMVMatrix * vec4(aVertexPosition, 1.0); vTextureCoord = aTextureCoord; }";
}
gl.shaderSource(shader, str);
gl.compileShader(shader);
if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
alert(gl.getShaderInfoLog(shader));
return null;
}
return shader;
},
/**
* Method: resetCanvas
* 移动canvas到原点并清除canvas上的所有东西
*/
resetCanvas: function() {
// because the layerContainerDiv has shifted position (for non canvas layers), reposition the canvas.
if (this.redrawCanvas) {
this.redrawCanvas = false;
// clear canvas by reseting the size
// broken in Chrome 6.0.458.1:
// http://code.google.com/p/chromium/issues/detail?id=49151
this.canvas.width = this.map.viewPortDiv.clientWidth;
this.canvas.height = this.map.viewPortDiv.clientHeight;
this.canvasContext.viewportWidth = this.canvas.width;
this.canvasContext.viewportHeight = this.canvas.height;
//清空webgl
this.canvasContext.clearColor(0.0, 0.0, 0.0, 0);
this.canvasContext.enable(this.canvasContext.DEPTH_TEST);
this.canvasContext.viewport(0, 0, this.canvasContext.viewportWidth, this.canvasContext.viewportHeight);
this.canvasContext.clear(this.canvasContext.COLOR_BUFFER_BIT | this.canvasContext.DEPTH_BUFFER_BIT);
if (this.useCanvas) {
// store the current resolution and canvas position for transition
this.lastResolution = this.map.getResolution();
}
return true;
}
return false;
},
//重写grid里的initGriddedTiles
initGriddedTiles:function(bounds) {
this.isZoomming = false;
SuperMap.Layer.Grid.prototype.initGriddedTiles.apply(this,arguments);
this.lenRow = this.grid.length;
this.lenColumn = this.grid[0].length;
},
/**
* Method: getLayerPxFromLonLat
* A wrapper for the <SuperMap.Map.getLayerPxFromLonLat()> method,
* which takes into account that the canvas element has a fixed size and
* it always moved back to the original position.
*
* Parameters:
* lonlat - {<SuperMap.LonLat>}经纬度
*
* Returns:
* {<SuperMap.Pixel>}像素点
*/
getLayerPxFromLonLat: function(lonlat) {
return this.usesCanvas ? this.map.getPixelFromLonLat(lonlat) :
this.map.getLayerPxFromLonLat(lonlat);
},
/**
* Method: getLayerPxFromLonLat
* A wrapper for the <SuperMap.Map.getViewPortPxFromLayerPx()> method.
*
* Parameters:
* layerPx - {<SuperMap.Pixel>}
*
* Returns:
* {<SuperMap.Pixel>}
*/
getViewPortPxFromLayerPx: function(layerPx) {
return this.useCanvas ? layerPx : this.map.getViewPortPxFromLayerPx(layerPx);
},
/**
* Method: getURL
* 根据瓦片的bounds获取URL。
*
* Parameters:
* bounds - {<SuperMap.Bounds>} 瓦片的bounds。
*
* Returns:
* {String} 瓦片的URL。
*/
getURL: function (bounds) {
var me = this,
xyz;
bounds = me.adjustBounds(bounds);
xyz = me.getXYZ(bounds);
return me.getTileUrl(xyz);
},
/**
* Method: getXYZ
* 根据瓦片的bounds获取xyz值。
*
* Parameters:
* bounds - {<SuperMap.Bounds>} 瓦片的bounds。
*
* Returns:
* {Object} 一组键值对表示瓦片X, Y, Z方向上的索引。
*/
getXYZ: function (bounds) {
var me = this,
x, y, z,
map = me.map,
res = map.getResolution(),
tOrigin = me.getTileOrigin(),
tileSize = me.tileSize;
x = Math.round((bounds.left - tOrigin.lon) / (res * tileSize.w));
y = Math.round((tOrigin.lat - bounds.top) / (res * tileSize.h));
z = map.getZoom();
return {"x": x, "y": y, "z": z};
},
/**
* Method: getMemoryImg
* 根据瓦片的bounds获取内存中该记录的image。
*
* Parameters:
* bounds - {<SuperMap.Bounds>} 瓦片的bounds。
*
* Returns:
* {Object} image对象不存在返回null
*/
getMemoryImg: function(bounds){
var me = this, key = me.getXYZ(bounds);
key = "x" + key.x + "y" + key.y + "z" + key.z;
return me.memoryImg[key];
},
/**
* Method: addMemoryImg
* 记录瓦片bounds和对应的图片信息。
*
* Parameters:
* bounds - {<SuperMap.Bounds>} 瓦片的bounds。
* image - {<Image>} 瓦片对应的图片信息
*
*/
addMemoryImg:function(bounds, image, context){
var me = this;// key = me.getXYZ(bounds);
if(me.bufferImgCount == 0)
return;
var newImgTag = context.newImgTag;
if(newImgTag&&newImgTag!=""){
//删除缓存图片
if(me.memoryKeys.length >= me.bufferImgCount){
var keyDel = me.memoryKeys.shift();
me.memoryImg[keyDel] = null;
delete me.memoryImg[keyDel];
}
var keys = newImgTag.split("_");
var key = "x" + keys[0] + "y" + keys[1] + "z" + keys[2];
//缓存图片并保存索引。
me.memoryImg[key] = image;
me.memoryKeys.push(key);
}
},
/**
* Method: initResolutions
* 初始化Resolutions数组。重写基类方法
*/
initResolutions: function () {
// 我们想要得到resolutions以下是我们的策略
// 1. 如果在layer配置中定义了resolutions和scales使用它们
// 2. 如果在layer配置中定义resolutions使用它
// 3. 否则如果在layer配置中定义scales那么从这些scales中得出resolutions
// 4. 再者试图从在layer配置中设置的 maxResolution,minResolution, numZoomLevels, maxZoomLevel 计算出resolutions
// 5. 如果在map中设置了resolutions和scales使用它们
// 6. 如果我们仍然没有获得resolutions并且resolutions在map中已经定义了使用它们
// 7. 否则如果scales在map中定义了那么从scales中得出resolutions
// 8. 再者试图从在map中设置的maxResolution, minResolution, numZoomLevels, maxZoomLevel 计算出resolutions。
var me = this,
i, len, p, startZoomLevel,
props = {},
alwaysInRange = true;
//如果在layer中定义了resolutions和scales直接使用layer的resolutions和scales并且通过它们计算出
//maxResolution, minResolution, numZoomLevels, maxScale和minScale
if (me.resolutions && me.scales) {
var len = me.resolutions.length;
me.resolutions.sort(function(a, b) {
return (b - a);
});
if (!me.maxResolution) {
me.maxResolution = me.resolutions[0];
}
if (!me.minResolution) {
me.minResolution = me.resolutions[len-1];
}
me.scales.sort(function(a, b) {
return (a - b);
});
if (!me.maxScale) {
me.maxScale = me.scales[len-1];
}
if (!me.minScale) {
me.minScale = me.scales[0];
}
me.numZoomLevels = len;
return;
}
// 从layer的配置中获得计算resolutions的数据。
for (i = 0, len = me.RESOLUTION_PROPERTIES.length; i < len; i++) {
p = me.RESOLUTION_PROPERTIES[i];
props[p] = me.options[p];
if (alwaysInRange && me.options[p]) {
alwaysInRange = false;
}
}
if (me.alwaysInRange == null) {
me.alwaysInRange = alwaysInRange;
}
// 如果没有得到resolutions利用scales计算resolutions。
if (props.resolutions == null) {
props.resolutions = me.resolutionsFromScales(props.scales);
}
// 如果仍没有得到resolutions利用layer配置中设置的
//maxResolution,minResolution, numZoomLevels, maxZoomLevel 计算出resolutions
if (props.resolutions == null) {
props.resolutions = me.calculateResolutions(props);
}
//如果没有从layer的配置数据中获得resolutions并且map中同时设置了resolutions和scales直接使用它们
//并且通过它们计算出maxResolution, minResolution, numZoomLevels, maxScale和minScale
if (me.map.resolutions && me.map.scales) {
me.resolutions = me.map.resolutions;
me.scales = me.map.scales;
var len = me.resolutions.length;
me.resolutions.sort(function(a, b) {
return (b - a);
});
if (!me.maxResolution) {
me.maxResolution = me.resolutions[0];
}
if (!me.minResolution) {
me.minResolution = me.resolutions[len-1];
}
me.scales.sort(function(a, b) {
return (a - b);
});
if (!me.maxScale) {
me.maxScale = me.scales[len-1];
}
if (!me.minScale) {
me.minScale = me.scales[0];
}
me.numZoomLevels = len;
return;
}
//如果此时仍没有计算出resolutions那么先从baselayer上获取,之后从map中获得方法同上最后再计算。
if (props.resolutions == null) {
for (i = 0, len = me.RESOLUTION_PROPERTIES.length; i<len; i++) {
p = me.RESOLUTION_PROPERTIES[i];
props[p] = me.options[p] != null ?
me.options[p] : me.map[p];
}
if (props.resolutions == null) {
props.resolutions = me.resolutionsFromScales(props.scales);
}
if (props.resolutions == null) {
if(me.map.baseLayer!=null){
props.resolutions = me.map.baseLayer.resolutions;
}
}
if (props.resolutions == null) {
props.resolutions = me.calculateResolutions(props);
}
}
var maxRes;
if (me.options.maxResolution && me.options.maxResolution !== "auto") {
maxRes = me.options.maxResolution;
}
if (me.options.minScale) {
maxRes = SuperMap.Util.getResolutionFromScaleDpi(me.options.minScale, me.dpi, me.units, me.datumAxis);
}
var minRes;
if (me.options.minResolution && me.options.minResolution !== "auto") {
minRes = me.options.minResolution;
}
if (me.options.maxScale) {
minRes = SuperMap.Util.getResolutionFromScaleDpi(me.options.maxScale, me.dpi, me.units, me.datumAxis);
}
if (props.resolutions) {
props.resolutions.sort(function(a, b) {
return (b - a);
});
if (!maxRes) {
maxRes = props.resolutions[0];
}
if (!minRes) {
var lastIdx = props.resolutions.length - 1;
minRes = props.resolutions[lastIdx];
}
}
me.resolutions = props.resolutions;
if (me.resolutions) {
len = me.resolutions.length;
me.scales = [len];
if(me.map.baseLayer){
startZoomLevel = this.calculateResolutionsLevel(me.resolutions);
}
else{
startZoomLevel = 0;
}
for (i = startZoomLevel; i < len + startZoomLevel; i++) {
me.scales[i] = SuperMap.Util.getScaleFromResolutionDpi(me.resolutions[i- startZoomLevel], me.dpi, me.units, me.datumAxis);
}
me.numZoomLevels = len;
}
me.minResolution = minRes;
if (minRes) {
me.maxScale = SuperMap.Util.getScaleFromResolutionDpi(minRes, me.dpi, me.units, me.datumAxis);
}
me.maxResolution = maxRes;
if (maxRes) {
me.minScale = SuperMap.Util.getScaleFromResolutionDpi(maxRes, me.dpi, me.units, me.datumAxis);
}
},
/**
* Method: calculateResolutionsLevel
* 根据resolutions数组计算scale数组
*
* Parameters:
* resolutions - {Array({Number})}resolutions数组
*/
calculateResolutionsLevel: function(resolutions){
var me = this, j, len, resolution,
baseLayerResolutions;
baseLayerResolutions = me.map.baseLayer.resolutions;
len = baseLayerResolutions.length;
resolution = resolutions[0];
for(j=0; j<len; j++){
if(resolution == baseLayerResolutions[j]){
return j;
}
}
return 0;
},
/**
* Method: resolutionsFromScales
* 根据scales数组计算resolutions数组重写基类方法
*
* Parameters:
* scales - {Array({Number})}scales数组
*/
resolutionsFromScales: function (scales) {
if (scales == null) {
return;
}
var me = this,
resolutions, len;
len = scales.length;
resolutions = [len];
for (var i = 0; i < len; i++) {
resolutions[i] = SuperMap.Util.getResolutionFromScaleDpi(
scales[i], me.dpi, me.units, me.datumAxis);
}
return resolutions;
},
/**
* Method: calculateResolutions
* 根据已提供的属性计算resolutions数组重写基类方法
*
* Parameters:
* props - {Object}
*
* Return:
* {Array({Number})} resolutions数组.
*/
calculateResolutions: function (props) {
var me = this,
maxResolution = props.maxResolution;
if (props.minScale != null) {
maxResolution = SuperMap.Util.getResolutionFromScaleDpi(props.minScale, me.dpi, me.units, me.datumAxis);
} else if (maxResolution == "auto" && me.maxExtent != null) {
var viewSize, wRes, hRes;
viewSize = me.map.getSize();
wRes = me.maxExtent.getWidth() / viewSize.w;
hRes = me.maxExtent.getHeight() / viewSize.h;
maxResolution = Math.max(wRes, hRes);
}
var minResolution = props.minResolution;
if (props.maxScale != null) {
minResolution = SuperMap.Util.getResolutionFromScaleDpi(props.maxScale, me.dpi, me.units, me.datumAxis);
} else if (props.minResolution == "auto" && me.minExtent != null) {
var viewSize, wRes, hRes;
viewSize = me.map.getSize();
wRes = me.minExtent.getWidth() / viewSize.w;
hRes = me.minExtent.getHeight()/ viewSize.h;
minResolution = Math.max(wRes, hRes);
}
if(typeof maxResolution !== "number" &&
typeof minResolution !== "number" &&
this.maxExtent != null) {
// maxResolution for default grid sets assumes that at zoom
// level zero, the whole world fits on one tile.
var tileSize = this.map.getTileSize();
maxResolution = Math.max(
this.maxExtent.getWidth() / tileSize.w,
this.maxExtent.getHeight() / tileSize.h
);
}
var maxZoomLevel = props.maxZoomLevel;
var numZoomLevels = props.numZoomLevels;
if (typeof minResolution === "number" &&
typeof maxResolution === "number" && numZoomLevels === undefined) {
var ratio = maxResolution / minResolution;
numZoomLevels = Math.floor(Math.log(ratio) / Math.log(2)) + 1;
} else if (numZoomLevels === undefined && maxZoomLevel != null) {
numZoomLevels = maxZoomLevel + 1;
}
if (typeof numZoomLevels !== "number" || numZoomLevels <= 0 ||
(typeof maxResolution !== "number" &&
typeof minResolution !== "number")) {
return;
}
var resolutions = [numZoomLevels];
var base = 2;
if (typeof minResolution == "number" && typeof maxResolution == "number") {
base = Math.pow(
(maxResolution / minResolution),
(1 / (numZoomLevels - 1))
);
}
if (typeof maxResolution === "number") {
for (var i = 0; i < numZoomLevels; i++) {
resolutions[i] = maxResolution / Math.pow(base, i);
}
} else {
for (i = 0; i < numZoomLevels; i++) {
resolutions[numZoomLevels - 1 - i] =
minResolution * Math.pow(base, i);
}
}
return resolutions;
},
CLASS_NAME: "SuperMap.Layer.WebGLLayer"
});