#!/bin/bash
# Runs a program from the desktop on the GPU: in a gamescope of its own that draws straight into
# the app's compositor (wayland-0), not inside labwc. The desktop is composited by pixman, and
# pixman gives its windows no DMA-BUFs - a Vulkan program there fails at its swapchain
# (VK_ERROR_SURFACE_LOST, RPCS3's error). Here it gets the same path as a program started from the
# app's rail: full screen over the desktop until it exits, then the desktop is back.
#   droiddeck-gpu <program> [args...]
set -u
[ $# -gt 0 ] || { echo "usage: droiddeck-gpu <program> [args...]" >&2; exit 64; }
if [ -n "${BL_DEBUG_DIR:-}" ]; then
  exec >>"$BL_DEBUG_DIR/desktop.log" 2>&1
fi
width=${BL_WIDTH:-1280}
height=${BL_HEIGHT:-720}
args=(--backend wayland --expose-wayland -f -W "$width" -H "$height" -w "$width" -h "$height")
if [ "${BL_FPS:-0}" -gt 0 ]; then
  args+=(-r "$BL_FPS")
elif [ "${BL_REFRESH:-0}" -gt 0 ]; then
  args+=(-r "$BL_REFRESH")
fi
[ "${BL_HDR:-0}" = 1 ] && args+=(--hdr-enabled)
echo "== droiddeck-gpu $(date -u +%H:%M:%S): $* (gamescope ${width}x${height} on wayland-0)"
# gamescope is a client of the app's compositor, beside labwc; the program inside it reaches it
# through gamescope's own Xwayland, as in a Steam session.
export WAYLAND_DISPLAY=wayland-0
export GDK_BACKEND=x11 QT_QPA_PLATFORM=xcb SDL_VIDEODRIVER=x11
# AppImages cannot mount under proot; the menu entries already say so, a hand-typed one may not.
export APPIMAGE_EXTRACT_AND_RUN=1
gamescope "${args[@]}" -- "$@"
rc=$?
echo "== droiddeck-gpu $(date -u +%H:%M:%S): exited $rc"
exit $rc