sch2fig/test/: tools for comparison with reference results

sch2fig/test/comp

@@ -0,0 +1,15 @@
+#!/bin/sh
+diffs=0
+rm -f _diff*png
+for n in out*.png; do
+	ref=ref${n#out}
+	diff=_diff${n#out}
+	if ! compare -metric AE $ref $n - >/dev/null; then
+		diffs=`expr $diffs + 1`
+		compare -metric AE $ref $n $diff
+	fi
+done
+echo
+[ $diffs = 0 ] && exit 0
+echo "$diffs difference(s)" 1>&2
+exit 1