JavaScript实现的拼图算法分析

<div id="selectpanel"></div><div id="orginalimg"></div><div id="mathpanel"></div>

*{margin: 0;padding: 0;}

function Puzzle(imgWidth,imgHeight,cuttingoffX,cuttingoffY,img){  var selectPanel=document.getElementById("selectpanel");//拼图面板  var mathPanel=document.getElementById("mathpanel");//拼图匹配面板  var orginalImg=document.getElementById("orginalimg");//参照图面板  selectPanel.style.cssText='width: auto;height: auto;border: 2px solid black;overflow: hidden;float: left;margin: 10px;';  mathPanel.style.cssText='width: auto;height: auto;border: 2px solid black;overflow: hidden;float: right;margin: 10px;';  var amount=(imgWidth/cuttingoffX)*(imgHeight/cuttingoffY);//根据自定义每块拼图的宽高，计算拼图的总数量  var jsonPosition=[];  for(var i=0;i<amount;i++){//一个数组模拟成一个二维矩阵，用json来存这个矩阵，并且每个位置给它一个匹配值M    jsonPosition[i]={X:i%(imgWidth/cuttingoffX),Y:parseInt(i/(imgHeight/cuttingoffY)),M:i};  }  for(var c=0;c<amount;c++){//随机生成拼图位置    var divImg=document.createElement("div");    divImg.style.width=cuttingoffX+"px";    divImg.style.height=cuttingoffY+"px";    divImg.style.backgroundImage="url(img/"+img+")";    divImg.style.backgroundRepeat="no-repeat";    divImg.style.border="1px dashed gray";    divImg.style.float="left";    divImg.style.cursor="pointer";    if(c%(imgWidth/cuttingoffX)==0&&c!=0)    divImg.style.clear="left";    var rendomPositon=jsonPosition.splice(Math.floor(Math.random()*jsonPosition.length),1)[0];    divImg.style.backgroundPosition=rendomPositon['X']*(-cuttingoffX)+'px'+' '+rendomPositon['Y']*(-cuttingoffY)+'px';    divImg.draggable="true";    divImg.maths=rendomPositon["M"];    selectPanel.appendChild(divImg);  }  for(var c=0;c<amount;c++){//生成拼图匹配面板    var divEmpty=document.createElement("div");    divEmpty.style.width=cuttingoffX+"px";    divEmpty.style.height=cuttingoffY+"px";    divEmpty.style.border="1px solid gray";    divEmpty.style.float="left";    if(c%(imgWidth/cuttingoffX)==0&&c!=0)    divEmpty.style.clear="left";    divEmpty.maths=c;    mathPanel.appendChild(divEmpty);  }  var orginalImgWidth=document.body.clientWidth-(selectPanel.offsetWidth+selectPanel.offsetLeft+10)*2;  orginalImg.style.cssText="width: "+orginalImgWidth+"px;height:"+orginalImgWidth+"px;position:absolute;left:50%;margin-left:"+(-orginalImgWidth/2)+"px;top:10px;";  orginalImg.style.background="url(img/"+img+") no-repeat 0 0";  orginalImg.style.backgroundSize=orginalImgWidth+"px "+orginalImgWidth+"px";  var divImgs=selectPanel.getElementsByTagName("div");  var divEmptys=mathPanel.getElementsByTagName("div");  for(var e=0;e<divImgs.length;e++){    divImgs[e].ondragstart=function(event){//鼠标开始拖拽拼图，并且拿到它的匹配值maths      var event=event||window.event;      event.dataTransfer.setData("math",this.maths);    }    divImgs[e].ondrag=function(){    }    divImgs[e].ondragend=function(){    }    divEmptys[e].ondragenter=function(){      this.style.backgroundColor="red";    }    divEmptys[e].ondragover=function(event){//取消在拼图匹配面板的默认事件，否则ondrop无效      return false;    }    divEmptys[e].ondragleave=function(){      this.style.backgroundColor="transparent";    }    divEmptys[e].ondrop=function(event){//拖拽的拼图在匹配面板放下时执行函数      var event=event||window.event;      this.style.backgroundColor="transparent";      if(event.dataTransfer.getData("math")==this.maths){//判断拼图传过来的maths匹配值是否和匹配面板的maths一样，如果是则匹配成功        for(var i=0;i<divImgs.length;i++){          if(divImgs[i].maths==this.maths){            this.style.backgroundImage=divImgs[i].style.backgroundImage;            this.style.backgroundRepeat=divImgs[i].style.backgroundRepeat;            this.style.backgroundPosition=divImgs[i].style.backgroundPosition;            divImgs[i].setAttribute("draggable","false");            divImgs[i].style.background="none";          }        }      }    }  }}//浏览器窗口发生变化时的图片处理window.onresize=function(){  var selectPanel=document.getElementById("selectpanel");  var orginalImg=document.getElementById("orginalimg");  var orginalImgWidth=document.body.clientWidth-(selectPanel.offsetWidth+selectPanel.offsetLeft+10)*2;  orginalImg.style.width=orginalImg.style.height=orginalImgWidth+"px";  orginalImg.style.marginLeft=-orginalImgWidth/2+"px";  orginalImg.style.backgroundSize=orginalImgWidth+"px "+orginalImgWidth+"px";}

window.onload=function(){  //图的原始宽度(原图宽)，图的原始高度(原图高)，自定每块拼图的宽度(能被原图宽整除)，自定每块拼图的高度(能被原图高整除)，图片名(需放在img下)  Puzzle(500,500,125,125,"haqi.jpg");}

window.onload=function(){  //图的原始宽度(原图宽)，图的原始高度(原图高)，自定每块拼图的宽度(能被原图宽整除)，自定每块拼图的高度(能被原图高整除)，图片名(需放在img下)  Puzzle(500,500,100,100,"beauty.jpg");}