#!/bin/csh -f
#+
# level_check -- acquire a quick DEIMOS image to check exposure levels
#
# Purpose:
#	Snaps an image only a few rows in height without disk write, 
#	centered on the direct readout window
#
# Usage:
#	level_check [n_lines [ttime] ]
# 
# Arguments:
#	n_lines = number of CCD lines to read out [default=100; min=10]
#	ttime = exposure time [default = 1 sec]
# 
# Output:
#	Transcript to STDOUT
# 
# Restrictions:
#	None
# 
# Exit values:
#	 0 = normal completion
#	 1 = wrong number of arguments
#
# Example:
#	1) Acquire a 1 sec image reading out 100 rows:
#		level_check
# 
#	2) Acquire a 1 sec image reading out 10 rows:
#		level_check 10
#
#	3) Acquire a 10-sec image reading out 50 rows:
#		level_check 50 10
#-
# Modification history:
#	2002-Oct-13	GDW	Original version
#	2002-Oct-14	GDW	Added minimum width parameter
#	2002-Oct-28	GDW	Reduced minwidth to 10; added onintr
#	2003-Jul-31	GDW	Added AUTOPANE support
#-----------------------------------------------------------------------

set buf = $0
set cmd = $buf:t
set usage = "Usage: $cmd [n_lines [ttime]]"
@ minwidth = 10

# verify args...
if ( $#argv > 2 ) then
  printf "$usage\n"
  exit 1
endif

# optional arg #1 is the number of lines to read out...
if ( $#argv >= 1 ) then
    @ width = $1
    shift
else
    @ width = 100
endif
@ half_width = $width / 2

# optional arg #2 is the integration time...
if ( $#argv >= 1 ) then
    set ttime = $1
else
    set ttime = 1
endif

# validate args...
if ( $width < $minwidth ) then
    printf "ERROR -- readout window must include at least $minwidth rows.\n"
    exit 2
endif

# get the current window setup...
set buf = `show -s deiccd -terse window`
@ chip   = $buf[3]
@ xstart = $buf[5]
@ ystart = $buf[7]
@ xlen   = $buf[9]
@ ylen   = $buf[11]

# locate the center row...
@ yc = $ystart + $ylen / 2

# define new starting and ending rows...
@ y1 = $yc - $half_width

# save old parameters...
set old_mosmode = `show -s deiccd -terse mosmode`
set old_ttime   = `show -s deiccd -terse ttime`
set old_autopane = `show -s deiccd -terse autopane`

# reset the readout window...
onintr quit
modify -s deiccd ttime=$ttime
modify -s deiccd MOSMODE=Direct
modify -s deiccd window=$chip,$xstart,$y1,$xlen,$width
modify -s deiccd AUTOPANE=manual

# take exposure without disk write...
goibuf
beep

# restore settings:
quit:
modify -s deiccd ttime=$old_ttime
modify -s deiccd MOSMODE=$old_mosmode
modify -s deiccd window=$chip,$xstart,$ystart,$xlen,$ylen
modify -s deiccd AUTOPANE=$old_autopane
exit