#! /bin/csh -f -e

set usage = "$0 [ SCALESPECS ] OPTIONS BLACKFILE.ppm WHITEFILE.ppm > OUTFILE.gif"

# Same as linear-ppm-pair-to-gif (q.v.), but applies pnmscale
# first, with arguments SCALESPECS (see the pnmscale manpage)

if ( ( $#argv >= 3 ) && ( "x$1" !~ x-* ) ) then
  set scalespecs = ( "$1" ); shift;
else if ( ( $#argv >= 4 ) && ( \
    ( "x$1" == "x-xsize" )  || \
    ( "x$1" == "x-ysize" )  || \
    ( "x$1" == "x-xscale" ) || \
    ( "x$1" == "x-yscale" ) || \
    ( "x$1" == "x-width" )  || \
    ( "x$1" == "x-height" ) || \
    ( "x$1" == "x-pixels" ) || \
  ) ) then
  set scalespecs = ( "$1" "$2" ); shift; shift;
else if ( ( $#argv >= 5 ) && ( "x$1" == "x-xysize" ) ) then
  set scalespecs = ( "$1" "$2" "$3" ); shift; shift; shift;
else 
  echo "usage: ${usage}"; exit 1
endif

if ( $#argv < 2 ) then
  echo "usage: ${usage}"; exit 1
endif

@ wi = $#argv
@ bi = $#argv - 1
@ nopt = $#argv - 2

set options = ( $argv[1-$nopt] )
set bimg = $argv[$bi]
set wimg = $argv[$wi]
set btmp = "/tmp/$$-${bimg}"
set wtmp = "/tmp/$$-${wimg}"

cat ${bimg} | pnmscale ${scalespecs} > ${btmp}
cat ${wimg} | pnmscale ${scalespecs} > ${wtmp}
linear-ppm-pair-to-gif ${options} ${btmp} ${wtmp}
/bin/rm ${btmp} ${wtmp}