#!/bin/sh -
#
# gif2xbm [-t] files...
#
#   This uses the pbmplus package to convert GIF files into X bitmaps
# and X pixmap format files approriately. If a -t flag is given and the
# destination is a pixmap, than it will also set the None Color in the
# X Pixmap file to the transparency color used in the GIF file.
#
# WARNING: the X Bitmap output have been turned off, all output will be
# X pixmap format (if at all posiable).
# 
# WARNING: "giftrans" program is used to look up if the GIF contains
# multiple images in a GIF animation, and for the transparent color to
# preserve in the conversion (if -t option). As such it is required to
# be on your command path!
#
# NOTE: created files are placed in the current directory, not the
# directory of the source GIF file. This is a feature exploited by
# other scripts to convert whole directories of gif files into a
# completely different directory (the current).
# 
# Anthony Thyssen    1 September 1995    <anthony@cit.gu.edu.au>
#

b="                                                                          
"
b="     ${b}"

TRANS=
TMP=/tmp/gif2xbm.$$
trap "rm -f $TMP; exit 1" 1 2 3 15

Usage() {
  echo >&2 "Usage: gif2xbm [-t] [-q #] Gifs..."
  echo >&2 "    -t     preserve transparency"
  exit 10
}

loop=true
while [ "$loop" ]
do
  case "$1" in
  -t) TRANS=true; shift ;;      # preserve transparenty
  --) loop=; shift ;;
  *) loop= ;;
  esac
done

# Test command present
cmd_found() {
  expr match "`type $1 2>&1`" '.*not found' == 0 >/dev/null
}

if [ "$TRANS" ]; then
  cmd_found giftrans || echo >&2 "WARNING: giftrans not found!"
fi

for i in "$@" ; do
  echo -n "${b}  converting \"$i\"
"
  if [ ! -f "$i" ]; then
    echo -n "${b}"
    echo >&2 "Unable find file \"$i\""
    continue
  fi

  # --- find out the type ---
  name="`expr "//$i" : '.*/\([^/]*\)'`"           # remove path to file
  suffix="`expr "$name" : '.*\.\([^./]*\)$'`"     # extract last suffix 
  name="`expr "$name" : '\(.*\)\.[^.]*$'`"        # remove last suffix

  case "$name.$suffix" in
   *_anim.gif )
       echo -n "${b}"
       echo >&2 "Skipping GIF Animation: \"$i\""
       continue ;;
   *.gif ) ;;
   * ) echo -n "${b}"
       echo >&2 "Skipping non-GIF file: \"$i\""
       continue ;;
  esac

  # let's look for certain info
  numimages=`giftrans -L "$i" 2>&1 | tee $TMP |
                 grep 'Image Descriptor:' | wc -l`

  if [ $numimages -gt 1 ]; then 
    echo -n "${b}"
    echo >&2 "Skipping GIF Animation: \"$i\" (Renaming File)"
    path="`expr "$i" : '\(.*\)/'`"      # get file path (if any)
    mv "$i" "${path:-.}/${name}_anim.gif"
    continue
  fi

  # Determine transparent color if present
  tcolor=
  if [ "$TRANS" ]; then
    if  grep "Transparent Color Flag: True" $TMP >/dev/null; then
      tcolor=`awk '#  Figure out the Transparent color 
        $1 == "Color" && $2 ~ /^[0-9][0-9]*:$/ {
                color[substr($2, 1, length($2)-1)+0] = $9; }     # color table
        /Transparent Color Index:/ { c = $4; }             # TRANS color index
        END { print color[c] }                      # output transparent color
        ' $TMP | tr 'a-f' 'A-F' `
    fi
  fi

  # Convert gif and figure out destination format
  # case on the standard error on gif filter!!
  output=`giftopnm -verbose "$i" 2>&1 >$TMP` 
  case  "$output"  in
    #*PBM*)
    #  dest="$name.xbm"
    #  pbmtoxbm < $TMP |
    #    sed 's/static  *char/static unsigned char/;
    #         s/noname\([[_]\)/'"$name"'\1/'  > "$dest"
    #  ;;
    *P?M*)
      dest="$name.xpm"
      if [ "$tcolor" ]; then     # Output Pixmap with Transparency
        ppmtoxpm $TMP 2>/dev/null |
          sed "/colors/,/pixels/s/c $tcolor/c None/" |
          xpm-fix -o "$dest"
      else                       # Output Plain Pixmap
        ppmtoxpm $TMP 2>/dev/null | xpm-fix -o "$dest"
      fi
      ;;
    *) echo -n "${b}"
       echo >&2 "Unable to Parse GIF file \"$i\"!!!!"
       continue
  esac

  if [ ! -s "$dest" ]; then
    rm -f "$dest"
    echo -n "${b}"
    echo >&2 "Failed to convert \"$i\""
  fi

done

#echo "${b}DONE!"
echo -n "${b}"

rm -f $TMP