#!/bin/bash

# Check if AMD or NVIDIA GPU is connected
BrPath=
for Dir in /sys/class/backlight/amdgpu_*
do
    if [ -d "$Dir" ]
    then
       BrPath="$Dir"
       break
    fi
done

if [ -d "$BrPath" ]
then
    :
    #echo "Found AMD GPU folder $BrPath"
else
    BrPath=/sys/class/backlight/nvidia_0
    #echo "Didn't find AMD GPU, defaulting to $BrPath"
fi

# Step brightness by 10%
BrCur=$(cat $BrPath/brightness)
BrMax=$(cat $BrPath/max_brightness)
BrStep=$(($BrMax/10))

if [ "$(($BrCur + $BrStep))" -gt "$BrMax" ]
then
    echo "$BrMax" > "${BrPath}/brightness"
else
    BrCur=$(($BrCur+$BrStep))
    echo "$BrCur" > "${BrPath}/brightness"
fi