地图分块加载的实现

首先我们确定几个关键点：

窗口大小：windowW:Number,windowH:Number; 指的是可视区域的大小 我们可以把他想成客户端的分别率

单位地图大小： uintPicW：Number，uintPicH：Number; 指的是你切割的地图图片的单元大小。

当前地图坐标：position：point;这里大家就可以想成是你人物的当前所处坐标

 

清楚了上面的几个关键点，我们再来看下面的这个图：

 

 

阴影区域就是可视区域 A、B、C、D就是切割的单元地图

 

我们可以很容易的求出窗口的4个点，所占的地图的索引：

x0 = position.x - windowW/2;

x1 = position.x + windowW/2;

y0 = position.y - windowH/2;

y1 = position.y + windowH/2;

 

mapIndexX0 = uint(x0/256);

mapIndexX1 = uint(x1/256);

mapIndexY0 = uint(y0/256);

mapIndexY1 = uint(y1/256);

 

明白了上面的这些 下面这个类 相信大家都能看明白

package com.heptaFish.common.game.map.layers

{

import com.heptaFish.common.config.Config;

import com.heptaFish.common.core.BaseDisplayObject;

import com.heptaFish.common.game.map.impl.GameMap;

import com.heptaFish.common.hack.HeptaFishGC;

import com.heptaFish.common.loader.impl.ImageLoader;

import com.heptaFish.common.map.impl.HashMap;



import flash.display.Bitmap;

import flash.events.Event;

import flash.events.IOErrorEvent;

import flash.events.ProgressEvent;

import flash.geom.Point;

//地图层 图片

public class MapLayer extends BaseDisplayObject

{

  //图片读取器

  private var _imageLoader:ImageLoader;

  //地图图片 用于整块加载模式

  private var _image:Bitmap;

  //地图图片数组 用于栅格式加载地图模式

  private var _imageMap:HashMap;

  //小地图图片

  private var _simage:Bitmap;

  //

  private var _map:GameMap;

  private var _loadType:int;//加载类型 0：整块加载 1：栅格加载

  private var _visualWidth:Number;//地图可视宽度

  private var _visualHeight:Number;//地图可视高度

  private var _sliceWidth:Number;//地图切割单元宽度

  private var _sliceHeight:Number;//地图切割单元高度

  private var _preloadX:Number;//横向预加载屏数

  private var _preloadY:Number;//纵向预加载屏数

  private var _loadingMap:HashMap;//正在加载的屏map

  private var _waitLoadingArr:Array;//等待加载的loadermap

  

  private var _loadingNo:int = Config.getInt("concurrencyImageLoader");

  

  private var _screenImageRow:int;//一屏需要加载的横向图片数

  private var _screenImageCol:int;//一屏需要加载的纵向图片数

  private var _row:int;//总横向节点数

  private var _col:int;//总纵向节点数

  

  private var _nowPlayerPointoint;//当前人物所处的屏

  

  public function MapLayer(map:GameMap)

  {

   _map = map; 

   _loadType = parseInt(_map.mapXML.@loadType);

  }

  //读取地图图片

  public function load():void{

   //加载小地图

   var imageLoader:ImageLoader = new ImageLoader();

   var fileName:String =Config.getValue("mapLib") + _map.name + "/map_s.jpg";

   imageLoader.load(fileName);

   imageLoader.addEventListener(Event.COMPLETE,loadSmallSuccess);

   imageLoader.addEventListener(ProgressEvent.PROGRESS,loadingHandler);

   imageLoader.addEventListener(IOErrorEvent.IO_ERROR,ioErrorHandler);

   

  }

  //读取大地图成功

  private function loadBigSuccess(evet:Event):void{

   var imageLoader:ImageLoader = ImageLoader(evet.target);

   var image:Bitmap = new Bitmap(imageLoader._data);

   addChild(image);

   if(_simage != null && _simage.parent == this){

    removeChild(_simage);

    _simage = null;

   }

   this.width = image.width;

   this.height = image.height;

   imageLoader.removeEventListener(Event.COMPLETE,loadBigSuccess);

   imageLoader.removeEventListener(ProgressEvent.PROGRESS,loadingHandler);

   imageLoader.removeEventListener(IOErrorEvent.IO_ERROR,ioErrorHandler);

   imageLoader = null;

   dispatchEvent(evet);

   HeptaFishGC.gc();

  }

  //读取小地图成功

  private function loadSmallSuccess(evet:Event):void{

   var imageLoader:ImageLoader = ImageLoader(evet.target);

   var image:Bitmap = new Bitmap(imageLoader._data);

   image.width = _map.mapWidth;

   image.height = _map.mapHeight;

   addChild(image);

   this.width = image.width;

   this.height = image.height;

   imageLoader.removeEventListener(Event.COMPLETE,loadSmallSuccess);

   imageLoader.removeEventListener(ProgressEvent.PROGRESS,loadingHandler);

   imageLoader.removeEventListener(IOErrorEvent.IO_ERROR,ioErrorHandler);

   imageLoader = null;

   dispatchEvent(evet);

   HeptaFishGC.gc();   

   switch(_loadType){

    case 0://整块加载    

     //加载大地图

     var bfileName:String =Config.getValue("mapLib") + _map.name + "/map.jpg";

     var bLoader:ImageLoader = new ImageLoader(); 

     bLoader.load(bfileName);

     bLoader.addEventListener(Event.COMPLETE,loadBigSuccess);

     bLoader.addEventListener(ProgressEvent.PROGRESS,loadingHandler);

     bLoader.addEventListener(IOErrorEvent.IO_ERROR,ioErrorHandler);

     break;

    case 1:

     _loadingMap = new HashMap();

     _imageMap = new HashMap();

     _waitLoadingArr = new Array();

     _visualWidth = _map.app.screen.size.x;

     _visualHeight = _map.app.screen.size.y;

     _sliceWidth = parseFloat(_map.mapXML.@sliceWidth);

     _sliceHeight = parseFloat(_map.mapXML.@sliceHeight);

     _preloadX = parseFloat(_map.mapXML.@preloadX);

     _preloadY = parseFloat(_map.mapXML.@preloadY);

     _screenImageRow = Math.round(_visualWidth/_sliceWidth);

     _screenImageCol = Math.round(_visualHeight/_sliceHeight);

     _row = Math.ceil(_map.mapWidth/_sliceWidth);

     _col = Math.ceil(_map.mapHeight/_sliceHeight);

     loadSliceImage(_map.initPlayerPoint);

     break;

    default:

     break;

     

   }

  }

  

  //根据player坐标读取周边指定屏数地图

  private function loadSliceImage(playerPointoint):void{

   var nowX:int = Math.floor(playerPoint.x/_sliceWidth);//现在所处的索引X

   var nowY:int = Math.floor(playerPoint.y/_sliceHeight);//现在所处的索引Y

   var nowScreenX:int = Math.floor(nowX/_screenImageRow);//现在所处的屏索引X

   var nowScreenY:int = Math.floor(nowY/_screenImageCol);//现在所处的屏索引Y

//   trace("nowScreenX:" + nowScreenX);

//   trace("nowScreenY:" + nowScreenY);

   _nowPlayerPoint = new Point(nowScreenX,nowScreenY);

   loadScreenImage(nowScreenX,nowScreenY);

//   removeScreenImage(nowScreenX,nowScreenY);

   var startX:int = (nowScreenX - _preloadX < 0 ? 0 : nowScreenX - _preloadX);

   var startY:int = (nowScreenY - _preloadY < 0 ? 0 : nowScreenY - _preloadY);

   

   var endX:int = (nowScreenX + _preloadX > _row ? _row : nowScreenX + _preloadX);

   var endY:int = (nowScreenY + _preloadY > _col ? _col : nowScreenY + _preloadY);

   

   for(var xx:int = startX; xx < endX;xx++){

    for(var yy:int = startY; yy < endY;yy++){

     if(xx == nowScreenX && yy == nowScreenY){

      continue;

     }else{

      loadScreenImage(xx,yy);

     }

    }

   }

  }

  //加载指定屏的地图图片

  private function loadScreenImage(screenX:int,screenY:int):void{

   var starX:int = _screenImageRow*screenX < 0 ? 0 : _screenImageRow*screenX;

   var starY:int = _screenImageCol*screenY < 0 ? 0 : _screenImageCol*screenY;

   var endX:int = _screenImageRow*(screenX+1) > _row - 1 ? _row -1 : _screenImageRow*(screenX+1);

   var endY:int = _screenImageCol*(screenY+1) > _col-1  ? _col-1 : _screenImageCol*(screenY+1);

   for(var yy:int=starY;yy<endY+1;yy++){

    for(var xx:int = starX;xx<endX+1;xx++){

     var tempKey:String = yy+"_"+xx;

     if(!_loadingMap.containsValue(tempKey) && !_imageMap.containsKey(tempKey)){

      _waitLoadingArr.push(tempKey);

     }

    }

    _waitLoadingArr.reverse();

    loadImage();

   }

  }

  

  private function loadImage():void{

   if(_waitLoadingArr.length > 0){

    for(var i:int = 0;i<_loadingNo - _loadingMap.size();i++){

     var key:String = _waitLoadingArr.pop();

     var imageLoader:ImageLoader = new ImageLoader();

     var fileName:String = Config.getValue("mapLib") + _map.name +"/" + key  + ".jpg";

//     trace("fileName:" + fileName);

     _loadingMap.put(imageLoader,key);

     imageLoader.addEventListener(Event.COMPLETE,loadScreenImageSuccess);

     imageLoader.addEventListener(ProgressEvent.PROGRESS,loadingHandler);

     imageLoader.addEventListener(IOErrorEvent.IO_ERROR,ioErrorHandler);

     imageLoader.load(fileName);

    }

   }

  }

  

  //成功加载某屏的图片

  private function loadScreenImageSuccess(evet:Event):void{

   var imageLoader:ImageLoader = ImageLoader(evet.target);

   var tempStr:String = String(_loadingMap.getValue(imageLoader));

   var tempStrArr:Array = tempStr.split("_");

   var yy:int = tempStrArr[0];

   var xx:int = tempStrArr[1];

   _loadingMap.remove(imageLoader);

   var image:Bitmap = new Bitmap(imageLoader._data);

   image.x = _sliceWidth*xx;

   image.y = _sliceHeight*yy;

   this.addChild(image);

   _imageMap.put(yy+"_"+xx,image);

   imageLoader.removeEventListener(Event.COMPLETE,loadScreenImageSuccess);

   imageLoader.removeEventListener(ProgressEvent.PROGRESS,loadingHandler);

   imageLoader.removeEventListener(IOErrorEvent.IO_ERROR,ioErrorHandler);

   imageLoader = null;

   loadImage();

  }

  //卸载指定屏的地图图片

  private function removeScreenImage(screenX:int,screenY:int):void{

   var startX:int = (screenX - _preloadX < 0 ? 0 : screenX - _preloadX);

   var startY:int = (screenY - _preloadY < 0 ? 0 : screenY - _preloadY);

   

   var endX:int = (screenX + _preloadX > _row ? _row : screenX + _preloadX);

   var endY:int = (screenY + _preloadY > _col ? _col : screenY + _preloadY);

   var keyArr:Array = _imageMap.keys();

   for(var i:int = 0;i < keyArr.length;i++){

    var key:String = keyArr;

    var tempStrArr:Array = key.split("_");

    var yy:int = tempStrArr[0];

    var xx:int = tempStrArr[1];

    if(xx < startX*_screenImageRow || xx > endX * _screenImageRow || yy < startY*_screenImageCol || 



yy > endY*_screenImageCol){

     var image:Bitmap = Bitmap(_imageMap.getValue(key));

     this.removeChild(image);

     image = null;

     _imageMap.remove(key);

    }

   }

   HeptaFishGC.gc();

  }

  

  //检查是否需要加载

  public function checkLoad(pointoint):void{

   var nowX:int = Math.floor(point.x/_sliceWidth);//现在所处的索引X

   var nowY:int = Math.floor(point.y/_sliceHeight);//现在所处的索引Y

   var nowScreenX:int = Math.floor(nowX/_screenImageRow);//现在所处的屏索引X

   var nowScreenY:int = Math.floor(nowY/_screenImageCol);//现在所处的屏索引Y

   if(nowScreenX != _nowPlayerPoint.x || nowScreenY != _nowPlayerPoint.y){

    loadSliceImage(point);

   }

   

  }

}

}