Add silly gammatrip script (it's all dive's fault!)

1 files changed, 62 insertions, 0 deletions

diff --git a/gammatrip.sh b/gammatrip.sh
new file mode 100755
index 0000000..2b81a09
--- /dev/null
+++ b/gammatrip.sh
@@ -0,0 +1,62 @@
+#!/bin/bash
+
+# gammatrip.sh by B. Watson, licensed under the WTFPL.
+# Randomly change gamma in X, crude simulation of an acid trip.
+# It's also similar to the Atari 400/800/XL/XE "Atrract Mode"
+
+#### user-tweakable knobs:
+
+# seconds to sleep between gamma changes
+DELAY=${DELAY:-3}
+
+# max gamma for each individual color. lower number here means darker
+# colors on average. Units are 1/100ths of xrandr's --gamma floats,
+# MAX=100 means 1.0. Maximum value for MAX is 999.
+MAX=${MAX:-100}
+
+# minimum gamma for each color. don't set higher than MAX!
+# same units as MAX.
+MIN=${MIN:-30}
+
+#### end of user-tweakable knobs.
+
+init() {
+	trap cleanup SIGINT SIGABRT SIGHUP SIGTERM
+	OUTPUT="${OUTPUT:-$( xrandr | grep ' connected' | cut -d' ' -f1 )}"
+	echo "Using output '$OUTPUT'"
+}
+
+cleanup() {
+	echo "Restoring default gamma"
+	xrandr --output "$OUTPUT" --gamma "1.0:1.0:1.0"
+	exit 0
+}
+
+getrand() {
+	range=$(( MAX - MIN ))
+	echo $(( ( RANDOM % range ) + MIN ))
+}
+
+cycle() {
+	r=0; g=0; b=0
+	r="$( getrand )"
+	g="$( getrand )"
+	b="$( getrand )"
+	cmd="xrandr --output $OUTPUT --gamma "
+	for i in $r $g $b; do
+		cmd="$cmd$( printf "%03d" $i | sed 's,^.,&.,' ):"
+	done
+
+	# remove trailing colon. actually, xrandr doesn't care about it,
+	# but someday it might.
+	cmd="$( echo $cmd | sed 's,:$,,' )"
+
+	echo $cmd
+	$cmd
+}
+
+init
+while true; do
+	cycle
+	sleep "$DELAY"
+done