CCNode的一段源码如下：
void CCNode::sortAllChildren()
{
if (m_bReorderChildDirty)
{
int i,j,length = m_pChildren->data->num;
CCNode ** x = (CCNode**)m_pChildren->data->arr;
CCNode tempItem;
// insertion sort
for(i=1; i<length; i++)
{
tempItem = x;
j = i-1;
//continue moving element downwards while zOrder is smaller or when zOrder is the same but mutatedIndex is smaller
while(j>=0 && ( tempItem->m_nZOrder < x->m_nZOrder || ( tempItem->m_nZOrder== x->m_nZOrder && tempItem->m_nOrderOfArrival < x->m_nOrderOfArrival ) ) )
{
x = x;
j = j-1;
}
x = tempItem;
}
//don’t need to check children recursively, that’s done in visit of each child
m_bReorderChildDirty = false;
}
}
很明显，这是一段根据ZOrder坐标的排序，但是这里使用了冒泡排序。现在想问一下关于CCNode的工作原理，cocos2d每一帧在画图的时候是不是都会先排序所有CCNode的ZOrder，然后再画出来？？？如果是，在这里使用冒泡排序就不会慢吗
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