Split gitsch2ppm into its constituents.

- scripts/gitsch2ps: generate PS files for KiCad schematics in git
- scripts/normalizeschps: normalize eeschema Postscript
- scripts/schps2ppm: generate PPM files from normalized Eeschema Postscript
- scripts/gitsch2ppm: wrapper and cache manager for the above scripts

scripts/schps2ppm

@@ -0,0 +1,53 @@
+#!/bin/sh
+#
+# schps2ppm - Generate PPM files from normalized Eeschema Postscript
+#
+# Written 2010 by Werner Almesberger
+# Copyright 2010 Werner Almesberger
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+
+
+RES=1280x850
+
+
+usage()
+{
+    cat <<EOF 1>&2
+usage: $0 [options] [file.ps [file.ppm]]
+
+  -r XxY     image resolution (default: $RES)
+EOF
+    exit 1
+}
+
+
+while true; do
+    case "$1" in
+    -r)	[ -z "$2" ] && usage
+	RES="$2"
+	shift 2;;
+    -*)
+	usage;;
+    *)
+	break;;
+    esac
+done
+
+[ ! -z "$3" ] && usage
+in=${1:--}
+out=${2:-/dev/stdout}
+
+X=`echo $RES | sed 's/x.*//'`
+Y=`echo $RES | sed 's/.*x//'`
+IRES=${Y}x$X
+res=`expr 72 \* $X / 800`
+
+cat "$in" |
+  gs -sDEVICE=ppmraw -sOutputFile=- -g$IRES -r$res \
+  -dTextAlphaBits=4 -dGraphicsAlphaBits=4 -q - |
+  pnmflip -r270 >"$out"