gpu-auto

#!/usr/bin/env bash
# Run a command on the discrete GPU while on AC power, the integrated GPU on battery.
# Override with GPU_AUTO_FORCE=discrete|integrated.
set -euo pipefail

readonly AC_ONLINE=/sys/class/power_supply/ACAD/online
readonly VULKAN_DISCRETE='nvidia*'
readonly VULKAN_INTEGRATED='radeon*'

usage() {
    echo "usage: ${0##*/} <command> [args...]" >&2
    exit 2
}

on_ac_power() {
    [[ -r $AC_ONLINE && $(<"$AC_ONLINE") == 1 ]]
}

want_discrete() {
    case "${GPU_AUTO_FORCE:-}" in
        discrete) return 0 ;;
        integrated) return 1 ;;
        *) on_ac_power ;;
    esac
}

(($# > 0)) || usage

if want_discrete; then
    exec env \
        __NV_PRIME_RENDER_OFFLOAD=1 \
        __GLX_VENDOR_LIBRARY_NAME=nvidia \
        VK_LOADER_DRIVERS_SELECT="$VULKAN_DISCRETE" \
        "$@"
fi

exec env VK_LOADER_DRIVERS_SELECT="$VULKAN_INTEGRATED" "$@"