a13labs.infra/ansible/files/game_station/bin/system/launch_session.sh

#!/bin/bash
set -euo pipefail
LOG_FILE="$HOME/.local/logs/session.log"

log() { echo "[$(date --iso-8601=seconds)] $*" | tee -a "$LOG_FILE"; }

start_gamescope() {
  log "Starting Gamescope session..."

  CONF_FILE="$HOME/.config/gamescope/gamescope.conf"
  [ -f "$CONF_FILE" ] && source "$CONF_FILE"

  FRAMERATE=${FRAMERATE:-60}
  RESOLUTION=${RESOLUTION:-1920x1080}
  WIDTH="${RESOLUTION%x*}"
  HEIGHT="${RESOLUTION#*x}"

  export __GL_GSYNC_ALLOWED=1
  export __GL_VRR_ALLOWED=1
  export __GL_SHADER_DISK_CACHE=1
  export __GL_SYNC_TO_VBLANK=0
  export LIBVA_DRIVER_NAME=nvidia
  export __GLX_VENDOR_LIBRARY_NAME=nvidia
  export NVD_BACKEND=direct
  # export __GL_THREADED_OPTIMIZATIONS=1

  GAMESCOPE_BIN="$(command -v gamescope || true)"
  if [ -z "$GAMESCOPE_BIN" ]; then
    log "ERROR: gamescope not found in PATH"
    exit 127
  fi

  HDR_FLAG=""
  if [[ "$HDR_ENABLED" == "1" || "$HDR_ENABLED" == "true" || "$HDR_ENABLED" == "yes" ]]; then
      HDR_FLAG="--hdr-enabled"
      log "HDR flag added: --hdr-enabled"
  else
      log "HDR disabled, no HDR flag added"
  fi

  # Build gamescope argument array for safe quoting and readability
  GAMESCOPE_ARGS=(
    --generate-drm-mode fixed
    --fade-out-duration 200
    --cursor-scale-height 720
    -f
    -W "$WIDTH" -H "$HEIGHT"
    -w "$WIDTH" -h "$HEIGHT"
    --rt --mangoapp -e
    -r "$FRAMERATE"
  )

  # Append HDR flag if enabled
  if [ -n "${HDR_FLAG:-}" ]; then
    GAMESCOPE_ARGS+=("$HDR_FLAG")
  fi

  export XDG_CURRENT_DESKTOP=gamescope
  export XDG_SESSION_TYPE=wayland
  export DESKTOP_SESSION=gamescope

  log "Launching Gamescope: $GAMESCOPE_BIN ${GAMESCOPE_ARGS[*]} -- $*"
  sudo setcap 'CAP_SYS_NICE=eip' "$GAMESCOPE_BIN"
  # Execute gamescope inside a DBus session, preserving proper argument quoting
  exec dbus-run-session -- "$GAMESCOPE_BIN" "${GAMESCOPE_ARGS[@]}" -- "$@" >>"$LOG_FILE" 2>&1
}

start_kwin() {
  log "Starting KWin session..."
  KWIN_BIN="$(command -v kwin_wayland || true)"
  if [ -z "$KWIN_BIN" ]; then
    log "ERROR: kwin_wayland not found in PATH"
    exit 127
  fi

  export XDG_CURRENT_DESKTOP=plasma
  export XDG_SESSION_TYPE=wayland
  export DESKTOP_SESSION=plasma-wayland

  # Ensure we don't run nested; width/height/fullscreen are for the windowed backend.
  unset DISPLAY WAYLAND_DISPLAY
  KWIN_ARGS="--drm --exit-with-session"
  log "Launching KWin (DRM): $KWIN_BIN ${KWIN_ARGS} $*"
  exec dbus-run-session -- "$KWIN_BIN" ${KWIN_ARGS} "$@" >>"$LOG_FILE" 2>&1
}

export XDG_SEAT=seat0
export XDG_RUNTIME_DIR=/run/user/$(id -u)
export XDG_DATA_DIRS=/usr/local/share/:/usr/share/
export XDG_CONFIG_DIRS=/usr/local/etc/xdg:/etc/xdg

if [[ -f "$HOME/.desktop-session-plasma" ]]; then
  log "Plasma session selected."
  rm "$HOME/.desktop-session-plasma"
  start_kwin /usr/local/bin/launch_kde.sh
else
  log "Gamescope session selected."
  start_gamescope /usr/local/bin/launch_steam.sh
fi