#!/bin/csh -f
#+
# gmov -- move an object to a given position on the DEIMOS guider
#
# Purpose:
#	Given the starting pixel coordinates of an object on a
#	DEIMOS guider image, and destination coordinates, 
#	compute and apply the required telescope move to reposition
#	the object as desired.
#
# Usage:
#	gmov [-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 guider pixel (100,200) to pixel (300,400):
#		gmov 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:
#		gmov -n 100 200 300 400
#-
# Modification history:
#	2002-Jul-06	GDW	Original version
#-----------------------------------------------------------------------


# 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: gmov [-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 = `calc "$gscale * ($1 - $3)"`
set dy = `calc "$gscale * ($4 - $2)"`
echo "$string $dx arcsec in x and $dy arcsec in y"
if ( $move) gxy $dx $dy