/*
  html2canvas @VERSION@ <http://html2canvas.hertzen.com>
  Copyright (c) 2011 Niklas von Hertzen. All rights reserved.
  http://www.twitter.com/niklasvh

  Released under MIT License
*/
_html2canvas.Renderer = function(parseQueue, options){


    var queue = [];
   
    function sortZ(zStack){
        var subStacks = [],
        stackValues = [],
        zStackChildren = zStack.children,
        s,
        i,
        stackLen,
        zValue,
        zLen,
        stackChild,
        b, 
        subStackLen;
        

        for (s = 0, zLen = zStackChildren.length; s < zLen; s+=1){
            
            stackChild = zStackChildren[s];
            
            if (stackChild.children && stackChild.children.length > 0){
                subStacks.push(stackChild);
                stackValues.push(stackChild.zindex);
            }else{         
                queue.push(stackChild);
            }  
           
        }
      
        stackValues.sort(function(a, b) {
            return a - b;
        });
    
        for (i = 0, stackLen = stackValues.length; i < stackLen; i+=1){
            zValue = stackValues[i];
            for (b = 0, subStackLen = subStacks.length; b <= subStackLen; b+=1){
                
                if (subStacks[b].zindex === zValue){
                    stackChild = subStacks.splice(b, 1);
                    sortZ(stackChild[0]);
                    break;
                  
                }
            }        
        }
  
    }


    sortZ(parseQueue.zIndex);
    if ( typeof options._renderer._create !== "function" ) {
        throw new Error("Invalid renderer defined");
    }
    return options._renderer._create( parseQueue, options, document, queue, _html2canvas );

};