Tk_GetRootCoords - Compute root-window coordinates of window
Tk_GetRootCoords(tkwin, xPtr, yPtr)
Token for window.
Pointer to location in which to store root-window x-coordinate corresponding to left edge of tkwin's border.
Pointer to location in which to store root-window y-coordinate corresponding to top edge of tkwin's border.
This procedure scans through the structural information maintained by Tk to compute the root-window coordinates corresponding to the upper-left corner of tkwin's border. If tkwin has no border, then Tk_GetRootCoords returns the root-window coordinates corresponding to location (0,0) in tkwin. Tk_GetRootCoords is relatively efficient, since it doesn't have to communicate with the X server.
coordinates, root window