/*
*  图片裁剪
*  imgdom：图片dom对象 也可以传this
*  cutimgtype(裁剪当时): 居中裁剪autocut  按比例缩放scaling  拉伸stretching
*  cutimgparent: 父类选择器 例如div标签的id是mydiv  那么这里就填 #mydiv
*
*  例如：
*  cutimg(this,"autocut","#mydiv")  //传父标签
*  cutimg(this,"autocut")  //不传父标签
*/
function cutimg(imgdom,cutimgtype,cutimgparent){
    $(imgdom).each(function(){
        var $this=$(imgdom);

	    $this.css("csstext","");

        var objheight,objwidth;
        //ie7+浏览器都能兼容的函数封装:获取图片的原始尺寸
        if($this[0].naturalwidth && $this[0].naturalheight) {
            objwidth = $this[0].naturalwidth;
            objheight = $this[0].naturalheight;
        } else {
            var img = new image();
            img.src = $this[0].src;
            objwidth = img.width;
            objheight = img.height;
        }

        var parentheight,parentwidth;
        if (cutimgparent!=undefined){
            parentheight=$this.parents(cutimgparent).eq(0).height();//图片父容器高度
            parentwidth=$this.parents(cutimgparent).eq(0).width();//图片父容器宽度
        }else{
            if($this.parent().prop('tagname')=='a' || $this.parent().prop('tagname')=='a'){
                parentheight=$this.parent().parent().height();//图片父容器高度
                parentwidth=$this.parent().parent().width();//图片父容器宽度
            }else{
                parentheight=$this.parent().height();//图片父容器高度
                parentwidth=$this.parent().width();//图片父容器宽度
            }
        }

        var imgcsstext = "";

		if(cutimgtype == "autocut"){
			var ratio=objheight/objwidth;
			if(objheight > objwidth) {//赋值宽高
                if(parentwidth*ratio < parentheight){
                    imgcsstext = "width:"+parentheight/ratio+"px!important;height:"+parentheight+"px!important;";
                }else{
                    imgcsstext = "width:"+parentwidth+"px!important;height:"+parentwidth*ratio+"px!important;";
                }
                $this.css("csstext",imgcsstext);
			}
			else if(objheight<objwidth) {
                if(parentheight/ratio < parentwidth){
                    imgcsstext = "width:"+parentwidth+"px!important;height:"+parentwidth*ratio+"px!important;";
                }else{
                    imgcsstext = "width:"+parentheight/ratio+"px!important;height:"+parentheight+"px!important;";
                }
                $this.css("csstext",imgcsstext);
            }else{
                if(parentheight>parentwidth) {//赋值宽高
                    imgcsstext = "width:"+parentheight+"px!important;height:"+parentheight+"px!important;";
                    $this.css("csstext",imgcsstext);
                }else{
                    imgcsstext = "width:"+parentwidth+"px!important;height:"+parentwidth+"px!important;";
                    $this.css("csstext",imgcsstext);
                }
			}

/*            objheight=$this[0].height;//重新获取宽高
            objwidth=$this[0].width;*/
            objheight = $this.css("height").replace("px","");
            objwidth = $this.css("width").replace("px","");



            if(objheight>objwidth) {
                if(objheight == parentheight) {
                    imgcsstext = $this.attr("style")+";margin-left:"+(parentwidth-objwidth)/2+"px!important;border:0px!important;";
                }else{
                    imgcsstext = $this.attr("style")+";margin-top:"+(parentheight-objheight)/2+"px!important;border:0px!important;";
                }
                $this.css("csstext",imgcsstext);
            }else if(objheight<objwidth) {
                if(objwidth == parentwidth) {
                    imgcsstext = $this.attr("style")+";margin-top:"+(parentheight-objheight)/2+"px!important;border:0px!important;";
                }else{
                    imgcsstext = $this.attr("style")+";margin-left:"+(parentwidth-objwidth)/2+"px!important;border:0px!important;";
                }
                $this.css("csstext",imgcsstext);
            }else{
                if(parentheight >= parentwidth) {
                    imgcsstext = $this.attr("style")+";margin-left:"+(parentwidth-objwidth)/2+"px!important;border:0px!important;"
                    $this.css("csstext",imgcsstext);
                }else{
                    imgcsstext = $this.attr("style")+";margin-top:"+(parentheight-objheight)/2+"px!important;border:0px!important;";
                    $this.css("csstext",imgcsstext);
                }
            }

        }else{
            try
            {
                var widthrate = objwidth / parentwidth;
                var heightrate = objheight / parentheight;
                var imgwidth = 0;
                var imgheight = 0;

                if(widthrate > 1 || heightrate > 1 || widthrate < 1 || heightrate < 1)
                {
                    if(cutimgtype == "scaling")//按比例缩放
                    {
                        var rate = math.max(widthrate, heightrate);
                        imgwidth = math.max(1, math.min(objwidth/rate, parentwidth));
                        imgheight = math.max(1, math.min(objheight/rate, parentheight));
                    }
                    else//拉伸
                    {
                        imgwidth = parentwidth;
                        imgheight = parentheight;
                    }
                }
                else //大小合适
                {
                    imgwidth = parentwidth;
                    imgheight = parentheight;
                }

                imgcsstext += "width:"+imgwidth+"px!important;height:"+imgheight+"px!important;";
                $this.css("csstext",imgcsstext);

                if(imgwidth>imgheight) {
                    if(imgwidth != parentwidth){
                        imgcsstext = $this.attr("style")+";margin-left:"+(parentwidth-imgwidth)/2+"px!important;border:0px!important;";
                    }else{
                        imgcsstext = $this.attr("style")+";margin-top:"+(parentheight-imgheight)/2+"px!important;border:0px!important;";
                    }
                    $this.css("csstext",imgcsstext);
                }
                else
                {
                    if(imgheight != parentheight){
                        imgcsstext = $this.attr("style")+";margin-top:"+(parentheight-imgheight)/2+"px!important;border:0px!important;";
                    }else{
                        imgcsstext = $this.attr("style")+";margin-left:"+(parentwidth-imgwidth)/2+"px!important;border:0px!important;";
                    }
                    $this.css("csstext",imgcsstext);
                }
            }
            catch(e)
            {
            }
		}
    })
}