#!/bin/sh -
#
# xbmsplitup [options] size  file
#  
#  splitup a xbm xpm or pbmplus file into smaller images
# of the same format.  See usage below
#
TMP1=/tmp/xbmsplitup1.$$
TMP2=/tmp/xbmsplitup2.$$

Usage() {
  echo >&2 "Usage: $0 [options] size image"
  echo >&2 "  where  size  is either   #  or  #x#"
  echo >&2 "  output filename is of form  image_#.sfx"
  echo >&2 "  with # defaulting to hexidecimal"
  echo >&2 "    -a      use letters instead of numbers"
  echo >&2 "    -d      use decimal numbers not hexadecimal"
  echo >&2 "    -f 03d  format for output numbers"
  echo >&2 "    -x      use a #x# format for output names"
  echo >&2 "    -t      preserve the xpm trasparency"
  exit 10;
}

NumFmt='x'
CrossFmt=

while :; do
  case "$1" in
    -a) NumFmt='c'; shift ;;         # Ascii letters not Hexadecimal
    -d) NumFmt='d'; shift ;;         # Normal Numbers not Hexadecimal
    -f) NumFmt="$2"; shift; shift ;; # Normal Numbers not Hexadecimal
    -x) CrossFmt=true; shift ;;      # use a Cross format for output names
    -t) TRANS="#BFBFBF"; shift ;;    # the transparent color to use.
    -*) echo >&2 "Unknown option \"$1\""; Usage ;;
    *)  break;;
  esac
done

[ $# -ne 2 ] && Usage;

case "$1" in
  *x*)           #  resize to fully specified size
      Width=`expr "$1" : '\([0-9]*\)'`
      Height=`expr "$1" : '[0-9]*x\([0-9]*\)'`
      shift ;;
  *)             #  resize to a square of this size
      if  size=`expr "$1" : '\([0-9]*\)'`;  then
        Width=$size
        Height=$size
        shift
      else 
        Usage;
      fi ;;
esac

i="$1"
if [ ! -f "$i" ]; then
  echo >&2 "Unknown file \"$i\""
  Usage
fi

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

# --- convert to PbmPlus format ---
  case "$suffix" in
    xbm)  sed 's/unsigned //' "$i" | xbmtopbm > $TMP1 ;;
    xpm)
      if [ "$TRANS" ] && grep 'c  *None' "$i" >/dev/null; then
        # convert None to transparent color (above)
        sed "s/c  *[Nn]one/c $TRANS/g" "$i" |
           x2p.sed | xpmtoppm > "$TMP1"
      else
        x2p.sed "$i" | xpmtoppm  > $TMP1
      fi ;;
    pbm|pgm|ppm) 
         cp "$i" $TMP1 ;;
    *)   echo -n "${b}"
         echo >&2 "Unknown suffix for \"$i\""
         exit;
  esac

OUT=.
#mkdir $OUT

Xsize=`expr "\`pnmfile $TMP1\`" : '.*, \([0-9]*\)'`
Ysize=`expr "\`pnmfile $TMP1\`" : '.*by \([0-9]*\)'`

X=`expr $Xsize / $Width`   # columns
Y=`expr $Ysize / $Height`  # rows

if [ `expr \( $X \* $Width \)` -ne $Xsize ];  then
  echo >&2 "WARNING: $file not split width-wise correctly"
  X=`expr $X + 1`
fi

if [ `expr \( $Y \* $Height \)` -ne $Ysize ];  then
  echo >&2 "WARNING: $file not split width-wise correctly"
  Y=`expr $Y + 1` 
fi


x=0; y=0; c=0
while [ $y -lt $Y ]; do
  x=0;
  while [ $x -lt $X ]; do
    # split a pixmap from picture

    if [ "$CrossFmt" ]; then    
      if [ $NumFmt = 'c' ]; then
        n=${name}_`awk 'BEGIN{
              printf "%cx%c", "'"$x"'"+65, "'"$y"'"+65; exit; }'`
      else
        n=${name}_`awk 'BEGIN{
              printf "%'$NumFmt'x%'$NumFmt'", "'"$x"'", "'"$y"'"; exit; }'`
      fi
    else
      if [ $NumFmt = 'c' ]; then
        n=${name}_`awk 'BEGIN{ printf "%c", "'"$c"'"+65; exit; }'`
      else
        n=${name}_`awk 'BEGIN{ printf "%'$NumFmt'", "'"$c"'"; exit; }'`
      fi
    fi
    echo "$x x $y  -> $n.$suffix"

    pnmcut `expr $x \* $Width`   `expr $y \* $Height` \
           $Width  $Height  $TMP1  >  $TMP2

    # Insert convert back to correct format
    case "$suffix" in
      xbm)
	pbmtoxbm $TMP2 | sed 's/static  *char/static unsigned char/;
			s/noname\([[_]\)/'"$2"'\1/'  > $OUT/$n.$suffix
	;;
      xpm)
	if [ "$TRANS" ]; then
	  # replace transparent color with "None"
	    ppmtoxpm $TMP2  2>/dev/null |
	    sed "/colors/,/pixels/s/c $TRANS/c None/" |
	    xpm-fix -o $OUT/$n.$suffix
	else
	  # straight conversion
	    ppmtoxpm $TMP2  2>/dev/null | xpm-fix -o $OUT/$n.$suffix
	fi
        ;;
      pbm|pgm|ppm)
	cp $TMP2 $OUT/$n.$suffix
	;;
    esac

    c=`expr $c + 1`
    x=`expr $x + 1`
  done
  y=`expr $y + 1`
done