//大图浏览器
var gp_cur = 1;
var gid = 0;
var zoom_m = 320;
var zoom_w = 250;//左边
var zoom_x = 90; //小矩形
var zoom_b = 960;
var zoom_x_h = zoom_x / 2;
var mp_pos = null;
function object(objId){
	return document.getElementById(objId);
}
function getAbsPoint(e)
{
	if (e == null)
	{
		return;
	}
	var x = e.offsetLeft, y = e.offsetTop;
	while(e=e.offsetParent){x += e.offsetLeft; y += e.offsetTop;}
	x = x + 0;
	y = y + 0;
	return {"x": x, "y": y};
}

function locateZoom()
{
	var zw = object("bpd");
	if (zw == null)
	{
		return;
	}

	zw.style.left = mp_pos.x + zoom_m + 18 + "px";//左间距
	zw.style.top = mp_pos.y + 30  + "px"; //上间距
}

function slidebp()
{
	var x = event.clientX 
		- mp_pos.x 
		+ document.documentElement.scrollLeft; //小矩形宽
	var y = event.clientY 
		- mp_pos.y - 45
		+ document.documentElement.scrollTop;  //小矩形高

	movebigpic(x, y);
	movediv(x, y);

	var mp = object("mp");
	var bpd = object("bpd");
	var vpd = object("vpd");

	if (mp == null || bpd == null || vpd == null)
	{
		return;
	}

	mp.style.filter = "alpha(opacity=50)";

	bpd.style.display = "";
	vpd.style.display = "";
}

function closebp()
{
	var mp = object("mp");
	var bpd = object("bpd");
	var vpd = object("vpd");

	if (mp == null || bpd == null || vpd == null)
	{
		return;
	}

	mp.style.filter = "";

	bpd.style.display = "none";
	vpd.style.display = "none";
  }

function movebigpic(x, y)
{
  var bpd = object("bpd2");
  if (bpd == null)
  {
    return;
  }
  var xx = 0;
  var yy = 0;
  if (x < zoom_x_h)
  {
    xx = 0;
  }
  else if (x > (zoom_m - zoom_x_h))
  {
    xx = zoom_w - zoom_b;
  }
  else
  {
    xx = (zoom_x_h - x) * (zoom_b - zoom_w) / (zoom_m - zoom_x);
  }

  if (y < zoom_x_h)
  {
    yy = 0;
  }
  else if (y > (zoom_m - zoom_x_h))
  {
    yy = zoom_w - zoom_b;
  }
  else
  {
    yy = (zoom_x_h - y) * (zoom_b - zoom_w) / (zoom_m - zoom_x);
  }
  bpd.style.left = xx + "px";
  bpd.style.top = yy + "px";
}

function movediv(x, y)  //小矩形移动
{
  var vpd = object("vpd");
  if (vpd == null)
  {
    return;
  }

  var xx = 0;
  var yy = 0;
  if (x < zoom_x_h)
  {
    xx = 0;
  }
  else if (x > (zoom_m - zoom_x_h))
  {
    xx = zoom_m - zoom_x;
  }
  else
  {
    xx = x - zoom_x_h;
  }
  if (y < zoom_x_h)
  {
    yy = 0;
  }
  else if (y > (zoom_m - zoom_x_h))
  {
    yy = zoom_m - zoom_x;
  }
  else
  {
    yy = y - zoom_x_h;
  }
  vpd.style.left = (xx + mp_pos.x) + "px";
  vpd.style.top = (yy + mp_pos.y) + "px";
}