import struct
import maya.OpenMaya as om
import maya.OpenMayaUI as omUI


def readDepthMap(x, y):
    view = omUI.M3dView.active3dView()
    width = view.portWidth()
    height = view.portHeight()

    width = 1
    height = 1

    numPixels = width*height*4
    depth = [0.0]*numPixels
    util = om.MScriptUtil()
    util.createFromList(depth, numPixels)
    utilPtr = util.asUcharPtr()

    view.readDepthMap(x, y, width, height, utilPtr, omUI.M3dView.kDepth_Float)

    b1 = om.MScriptUtil.getUcharArrayItem(utilPtr, 0)
    b2 = om.MScriptUtil.getUcharArrayItem(utilPtr, 1)
    b3 = om.MScriptUtil.getUcharArrayItem(utilPtr, 2)
    b4 = om.MScriptUtil.getUcharArrayItem(utilPtr, 3)

    data = [b1,b2,b3,b4]
    print data # always 0's....
    b = struct.pack('4B', *data)
    return struct.unpack('>f', b)