cutiepi-rotation-scripts/bin/autorotate

#!/bin/bash

pidfile=/tmp/autorotate.pid
if ps -p $(cat "$pidfile" 2>/dev/null) >/dev/null; then
    echo "An autorotate process is already running - if not please remove $pidfile" >&2
    exit 1
fi

echo $$ > "$pidfile"
script_dir="$( cd -- "$( dirname -- "${BASH_SOURCE[0]}" )" &> /dev/null && pwd )"
source "$script_dir/cutiepi-screen-common"

# Turn off the HDMI interface. This actually shouldn't be required, but taking
# the second display into account would make the xinput coordinate transformation
# matrices more complex (TODO it can be tackled later if there's enough demand for
# screen rotation features while the tablet is attached to another screen)
xrandr --output HDMI-2 --off

# Default rotation: standard horizontal
screen_set_horizontal

monitor-sensor | while read line; do
    echo "$line" | egrep '^\s*Accelerometer orientation changed: ' >/dev/null || continue
    orientation=$(echo "$line" | awk '{print $4}')
    case "$orientation" in
        left-up) screen_set_horizontal;;
        normal) screen_set_vertical;;
        right-up) screen_set_horizontal_inverted;;
        bottom-up) screen_set_vertical_inverted;;
    esac
done