Gnome & Hidp - Multiple displays

flo.sh

#!/bin/sh
# https://wiki.archlinux.org/index.php/HiDPI#Multiple_displays
# https://gist.github.com/wvengen/178642bbc8236c1bdb67

EXT=`xrandr --current | sed 's/^\(.*\) connected.*$/\1/p;d' | grep -v ^eDP | head -n 1`
INT=`xrandr --current | sed 's/^\(.*\) connected.*$/\1/p;d' | grep -v ^DP | head -n 1`

ext_w=`xrandr | sed 's/^'"${EXT}"' [^0-9]* \([0-9]\+\)x.*$/\1/p;d'`
ext_h=`xrandr | sed 's/^'"${EXT}"' [^0-9]* [0-9]\+x\([0-9]\+\).*$/\1/p;d'`
int_w=`xrandr | sed 's/^'"${INT}"' [^0-9]* \([0-9]\+\)x.*$/\1/p;d'`
int_h=`xrandr | sed 's/^'"${INT}"' [^0-9]* [0-9]\+x\([0-9]\+\).*$/\1/p;d'`
scale_w=`gsettings get org.gnome.desktop.interface scaling-factor | cut -d' ' -f2`
scale_h=${scale_w}

ext_to_w=`expr ${ext_w} \* ${scale_w}`
ext_to_h=`expr ${ext_h} \* ${scale_h}`

# Generically if your HiDPI monitor is AxB pixels and your regular monitor is CxD and you are scaling by [ExF], the commandline for right-of is:
# xrandr --output eDP-1 --auto --output HDMI-1 --auto --panning [C*E]x[D*F]+[A]+0 --scale [E]x[F] --right-of eDP-1
xrandr --output "${INT}" --auto --output "${EXT}" --auto --scale ${scale_w}x${scale_h} --right-of "${INT}"

jerem.sh

#!/bin/bash
set -x

EXTERNAL_OUTPUT_LEFT="DP-1-8"
EXTERNAL_OUTPUT_RIGHT="DP-1-1"
#EXTERNAL_SIZE="--mode 3840x2160 --scale 1x1"
EXTERNAL_SIZE="--mode 3840x2160 --scale 0.75x0.75"
# EXTERNAL_SIZE="--mode 2560x1440 --scale 1x1"

INTERNAL_OUTPUT="eDP-1"
INTERNAL_SIZE="--mode 1920x1080 --scale 1x1"
# INTERNAL_SIZE="--mode 2560x1440 --scale 1x1"

xrandr | grep "$EXTERNAL_OUTPUT_RIGHT " -A 0 | grep " connected "
if [ $? -eq 0 ]; then
        xrandr --output $INTERNAL_OUTPUT --off --output $EXTERNAL_OUTPUT_LEFT $EXTERNAL_SIZE --primary --output $EXTERNAL_OUTPUT_RIGHT $EXTERNAL_SIZE --right-of $EXTERNAL_OUTPUT_LEFT
        exit 0
fi

xrandr --output $INTERNAL_OUTPUT $INTERNAL_SIZE --output $EXTERNAL_OUTPUT_LEFT --off --output $EXTERNAL_OUTPUT_RIGHT --off