;+
;
;   Define xstepper common block
;-
; scube - input data cube
; sinfo - strarry (image descriptions)
; delta - step size
; scale - 
; xs/ys - image dimensions
; rebin - boolean flag
; zoom  - zoom parameters
; interpol - boolean flag
; xstep_str
; subs - original subscripts
; current - pointer to subs
; nimages - number original
; ssmap - user defined subscripts
; sspnt - pointer to ssmap
; sscnt - n_elements(ssmap(defined))
; pixmap - (2xnimages) - subscript/pixmap window number
; pixpnt - pointer to pixmap
; pixcnt - n_elements(pixmap(defined))
; dispopt - display option
; backopt - background task option
; range - lo and high subscripts for data(range) display 
; over_info - if set, xyout the info on the output device
; areverse - if set, images sequence display reverses instead of wraps
; curwind - window number of current display
; zdata - zoomed (rebinned) data cube
; mag_fact - magnification factor
;-
 
common xstepper_blk, $
	scube, sinfo, delta,  				$
        scale, xs, ys, rebin, zoom,			$
	interpol, xstep_str , 	 			$
	subs, current, nimages,  			$
	ssrate, pixrate,				$
	ssmap,  sspnt, sscnt,				$
        pixmap, pixpnt, pixcnt,				$
	dispopt, backopt, range, minprog,		$
	over_info, last_title,				$
        areverse,					$
	reference, offsets, dx, dy, shift_fact, curwind, mag_fact