vincentbernat.i3wm-configuration/bin/xsettingsd-setup

#!/bin/sh

# Don't try to guess DPI. For a laptop, we don't want the same DPI as
# for an external screen. Just hardcode stuff...
case $(hostname),$(xrandr --current | \
                          sed -n 's/\([^ ]*\) connected .*[0-9][0-9]*x[0-9][0-9]*+[0-9][0-9]*+[0-9][0-9]* .*/\1/p' | \
                          sort | tr '\n' ':') in
    zoro,eDP1:)         dpi=144 ;;
    zoro,eDP-1:)        dpi=144 ;;
    zoro,eDP-1:HDMI-2:) dpi=144 ;;
    zoro,eDP-1:DP-1:)   dpi=144 ;;
    neo,HDMI-1:HDMI-2:) dpi=96 ;;
    neo,*)              dpi=192 ;;
    *)                  dpi=96 ;;
esac

# Build xsettingsd.local
{
    cat  ~/.config/awesome/xsettingsd
    echo Xft/DPI $(( $dpi*1024 ))
    echo Gdk/WindowScalingFactor $(( $dpi/96 ))
    echo Gdk/UnscaledDPI $(( $dpi*1024/($dpi/96) ))
} > ~/.config/awesome/xsettingsd.local

# Signal xsettingsd
pid=$(xprop -name xsettingsd _NET_WM_PID 2> /dev/null | awk '{print $NF}')
if [ x"$pid" = x ]; then
    xsettingsd -c ~/.config/awesome/xsettingsd.local &
else
    kill -HUP $pid
fi

# Also use xrdb for very old stuff (you know, LibreOffice)
echo Xft.dpi: $dpi | xrdb -merge