#!/bin/csh -fx
#+
# rotatloop -- step the rotator and pause between moves
#
# Purpose:
#	Given a stepsize, starting and ending rotator values, and a
#	desired time interval for sleeping, this script will move the
#	rotator and pause for the desired amount of time to allow one to
#	acquire data.  The default action is to mvoe from the negative
#	to the positive limits of rotation in 10-degree increments, pausing
#	for 10 seconds between moves.
#
# Usage:
#	rotatloop [-silent] [-prompt] [-goi] [start [stop [step [sleep]]]]
# 
# Arguments:
#	-silent = do not beep between moves
#	-goi	= acquire an image at each position
#	-prompt = require user to press <Enter> to move
#	start   = starting DEIMOS PA value [deg; default=-410]
#	stop	= ending DEIMOS PA value [deg; default=310]
#	step	= increment between moves [deg; default=10]
#	sleep	= number of seconds to sleep [sec; default=10]
# 
# Output:
#	Transcript written to STDOUT
# 
# Restrictions:
#	- Rotator must be in "Pos" mode to enable user control
#	- Angles must be provided in integer format
#	- If "-goi" is specified, pausing and sleeping are NOT done
# 
# Exit values:
#	0 = normal completion
#	1 = wrong number of arguments
#
# Examples:
#
#	1) Acquire an image every 10 deg between the rotator limits:
#		rotatloop -goi
# 
#	2) Rotate from 0 to 360 in 15 deg increments, pausing at each
#	position until the observer presses a key:
#		rotatloop -prompt 0 360 15
#
#-
# Modification history:
#	2002-Jul-03	GDW	Original version
#	2002-Sep-15	GDW	Acquire image at each position
#-----------------------------------------------------------------------

set buf = $0
set cmd = $buf:t
set usage = "Usage: $cmd [-silent] [-prompt] [-goi] [start [stop [step [sleep]]]]"

# define defaults...
set sound = 1		# default is to make sound after each rotation
set ask = 0		# default is to sleep rather than prompt
set goi = 0		# default is not to acquire an image at each position
@ start = -410		# default is to begin at negative limit
@ stop = 310		# default is to end at positive limit
@ step = 10		# default stepsize is positive 10 deg
@ n_sleep = 10		# default sleeptime is 10 seconds

# check for flags...
foreach arg ( $* )
    if ( "$arg" == "-silent") then
	shift
	set sound = 0
    endif

    if ( "$arg" == "-prompt") then
	shift
	set ask = 1
    endif

    if ( "$arg" == "-goi") then
	shift
	set goi = 1
    endif
end

# parse remaining args...
if ( $#argv >= 1 ) then
    @ start = $1
    shift
endif

if ( $#argv >= 1 ) then
    @ stop = $1
    shift
endif

if ( $#argv >= 1 ) then
    @ step = $1
    shift
endif

if ( $#argv >= 1 ) then
    @ n_sleep = $1
    shift
endif

if ( $#argv > 0 ) then
  printf "$usage\n"
  exit 1
endif

# ensure that step is positive by computing the absolute value...
set step = `abs $step`

# check which direction we will rotate...
if ( $start > $stop ) then
    set forward = 0
    @ step = -$step
else
    set forward = 1
endif

# verify the rotator mode...
set rotatmod = `show -s deirot -terse rotatmod`
if ( "$rotatmod" != "Pos" ) then
    printf "ERROR in $cmd: rotator is not in Pos mode\n"
    exit 2
endif

# initialize the angle to the starting value...
@ angle = $start

# start loop...
while (1)

    # set the rotator to the appropriate value...
    modify -s deirot rotatval=$angle

    # notify the user as appropriate...
    if ( $sound ) then
	beep
    endif

    # sleep or wait for response...
    if ( $goi ) then
	goi
    else if ( $ask ) then
	pause
    else
	printf "Sleeping for $n_sleep seconds"
	sleepdots $n_sleep
    endif

    # increment/decrement...
    @ angle += $step

    # check for whether to quit...
    if ( $forward ) then
	if ( $angle > $stop ) then
	    break
	endif
    else
	if ( $angle < $stop ) then
	    break
	endif
    endif
end