X-Git-Url: https://git.distorted.org.uk/~mdw/profile/blobdiff_plain/4cc1582bb02ad2771b491767882812eb0aca7015..7e571efe63719ddef999d78deccb42fb76a81aca:/bin/xzoomscr

diff --git a/bin/xzoomscr b/bin/xzoomscr
index b9551d8..eaf6254 100755
--- a/bin/xzoomscr
+++ b/bin/xzoomscr
@@ -4,22 +4,32 @@ case $# in 1) ;; *) echo >&2 "usage: $1 ZOOM"; exit 2 ;; esac
 zoom=$1
 
 ok=nil
+case $zoom in
+  */*/*) ;;
+  *[!0-9/]*) ;;
+  */*) ok=t mul=${zoom%/*} div=${zoom#*/} ;;
+  *) ok=t mul=1 div=$zoom ;;
+esac
+case $ok in nil) echo >&2 "$0: bad zoom $zoom"; exit 2 ;; esac
+case $(( $mul > $div )) in 1) echo >&2 "$0: zoom too high"; exit 2 ;; esac
+
+ok=nil
 case ${DISPLAY-nil} in
   *:*[!0-9.]*) ;;
   *:*.*.*) ;;
   *:*.*) ok=t dpybase=${DISPLAY%.*} ;;
   *:*) ok=t dpybase=$DISPLAY ;;
 esac
-case ok in nil) echo >&2 "$0: bad DISPLAY"; exit 2 ;; esac
+case $ok in nil) echo >&2 "$0: bad DISPLAY"; exit 2 ;; esac
 
 set -- $(xqueryptr); scr=$1 x=$2 y=$3
 DISPLAY=$dpybase.$scr; export DISPLAY
 
 eval $(xscsize -b)
 
-case $(( $XWIDTH%$zoom || $XHEIGHT%$zoom )) in
+case $(( $XWIDTH%$div || $XHEIGHT%$div )) in
   0) ;;
-  *) echo >&2 "$0: zoom multiplier doesn't divide screen size"; exit 2 ;;
+  *) echo >&2 "$0: zoom divisor doesn't divide screen size"; exit 2 ;;
 esac
 
 { read _
@@ -40,12 +50,12 @@ EOF
 
 case $found in nil) echo >&2 "$0: pointer not on any screen?"; exit 2 ;; esac
 
-case $zoom in
+case $(( $mul == $div )) in
   1) pan= ;;
   *) pan="--panning ${XWIDTH}x${XHEIGHT}" ;;
 esac
 
 xrandr --fb ${XWIDTH}x${XHEIGHT} \
 	--output $name \
-	--mode $(( $XWIDTH/$zoom ))x$(( $XHEIGHT/$zoom )) \
+	--mode $(( $mul*$XWIDTH/$div ))x$(( $mul*$XHEIGHT/$div )) \
 	$pan