#!/bin/csh -f
#+
# mov -- move an object to a given position on the DEIMOS detector
#
# Purpose:
#	Given the starting pixel coordinates of an object on a
#	DEIMOS image, and destination coordinates, compute and apply the
#	required telescope move the object as desired.
#
# Usage:
#	mov [-n] x1 y1 x2 y2
# 
# Arguments:
#	-n = no move, only print the required shift
#	x1 = starting column location of object [pixels]
#	y1 = starting row location of object [pixels]
#	x2 = ending column location of object [pixels]
#	y2 = ending row location of object [pixels]
# 
# Output:
# 
# Exit values:
#	0 = normal completion
#	1 = wrong number of arguments
#	2 = arguments not valid floating-point numbers
#
# Example:
#	1) Move a target at pixel (100,200) to pixel (300,400):
#		mov 100 200 300 400
#
#	2) Display the telescope move required to shift a target at
#	pixel (100,200) to the pixel (300,400) without moving the telecope:
#		mov -n 100 200 300 400
#-
# Modification history:
#	Date unknown	RWG	Original version
#	2000-Jul-05	GDW	Added documentation
#	2002-Jul-05	GDW	Adapted for DEIMOS
#-----------------------------------------------------------------------

# check for no-move flag...
if ( "$1" == "-n" ) then
  set string = "Required shift is"
  set move = 0
  shift
else
  set string = "Moving"
  set move = 1
endif

# check args...
if (${#argv} != 4) then  
  echo "Usage: mov [-n] x1 y1 x2 y2"
  exit 1
endif

# verify floating-point values...
is_float $* > /dev/null
if ( $status ) then
  echo "ERROR: Arguments must be valid floating-point numbers"
  exit 2
endif

# set scale...
source $DEIMOS_PROC_DIR/tel/set_scale

# apply shift...
set dx = `math "$pscale * ($1 - $3)"`
set dy = `math "$pscale * ($2 - $4)"`
echo "$string $dx arcsec in x and $dy arcsec in y"
if ( $move) mxy $dx $dy