#!/bin/sh

#
# mgpresize - rescales images in MGP file
#
# Author/License:
#   Christoph Dalitz
#   freely distributable under the terms of the GPL
#
# History:
#   06.10.2003  first creation
#

# initialization command line options
INMGP=""
EPSSCALE=0.75
PGM="`basename $0`"
USAGEMSG="Usage:\n\
\t$PGM [-s factor] mgpfile\n\
Options:\n\
\t-s fac  set scale factor to fac\n\
\t        default value: $EPSSCALE"

# argument loop
while [ $# -gt 0 ]
do
	case "$1" in
		-\?) echo -e "$USAGEMSG"; exit 0;;
		-s)  EPSSCALE=$2; shift;;
		*)   INMGP="$1";;
	esac
	shift
done

# plausi checks
if [ -z "$INMGP" -o ! -f "$INMGP" ]
then
	echo -e "$PGM:\n\tfile $INMGP not found" 1>&2
	echo -e "$USAGEMSG" 1>&2
	exit 1
fi
if echo "$EPSSCALE" | grep -q '[^0-9.]'
then
	echo -e "$PGM:\n\twrong scale factor '-s $EPSSCALE'" 1>&2
	echo -e "$USAGEMSG" 1>&2
	exit 1
fi

# do rescale
awk '
BEGIN {}
# rescale images
/^%.*image/ {
	N = split($0, field, " +");
	for (n=1; n<=N; n++) {
		if (match(field[n],"newimage")) {
			printf("%s ", field[n]);
			# check for scale options -(xy)zoom in next fields
			while ((n+1<=N) && !match(field[n+1],",")) {
				++n;
				printf("%s ", field[n]);
				if (field[n] == "-zoom") {
					printf("%d ", field[++n] * epsscale);
				} else if (field[n] == "-xyzoom") {
					printf("%d ", field[++n] * epsscale);
					printf("%d ", field[++n] * epsscale);
				}
			}
			if (n>=N) {printf("\n");}
		} else if (match(field[n],"image") && (n+5<=N)) {
			printf("%s ", field[n]);
			# next fields are: file scaleflag xscale yscale
			printf("%s ", field[++n]);
			printf("%s ", field[++n]);
			printf("%d ", field[++n] * epsscale);
			printf("%d ", field[++n] * epsscale);
		} else {
			if (n<N) {
				printf("%s ", field[n]);
			} else {
				printf("%s\n", field[n]);
			}
		}
	}
	next;
}
# print all other lines unchanged
{print;}
END{}
' epsscale=$EPSSCALE $INMGP