From 2c33cdc65f9317713d806af0d315a3d967f33459 Mon Sep 17 00:00:00 2001
From: Alexander Rosenberg <zanderpkg@pm.me>
Date: Mon, 5 Aug 2024 02:12:12 -0700
Subject: [PATCH] Add xwayland-game-wrapper

---
 xwayland-game-wrapper | 127 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 127 insertions(+)
 create mode 100755 xwayland-game-wrapper

diff --git a/xwayland-game-wrapper b/xwayland-game-wrapper
new file mode 100755
index 0000000..9f26a64
--- /dev/null
+++ b/xwayland-game-wrapper
@@ -0,0 +1,127 @@
+#!/usr/bin/env zsh
+
+setopt rcquotes
+
+# eprintf <format> [args...]
+function eprintf {
+    printf "${@}" >&2
+}
+
+# die <format> [args...]
+function die {
+    eprintf '\e[91mfatal\e[m: '"${1}\n" "${(@)@:2}"
+    exit 1
+}
+
+# print_help <argv[0]>
+function print_help {
+    printf 'usage: %s [OPTIONS...] <GAME> [ARGS...]\n' "${1}"
+    printf 'Run a game inside an Xwayland session with a window manager. This\n'
+    printf 'is very similar to gamescope, except that there is a window\n'
+    printf 'involved. The default window manager is OpenBox.\n'
+    printf '\n'
+    printf '  -h   Print this message, then exit.\n'
+    printf '  -w   Specify the window manager to use. This argument to this option will be\n'
+    printf '       passed to "sh -c".\n'
+    printf '  -r   Specify the resolution of the Xwayland display. This should in the form\n'
+    printf '       of ''WxH''. By default, the resolution of the currently focused output\n'
+    printf '       will be used.\n'
+    printf '  -d   Specify the current desktop environment (or standalone Wayland\n'
+    printf '       compositor). This is used if -r is not specified to find the resolution.\n'
+    exit 0
+}
+
+# get_current_desktop
+function get_current_desktop {
+    [[ -z "${XDG_CURRENT_DESKTOP}" ]] &&
+        die 'set $XDG_CURRENT_DESKTOP or pass -d top specify desktop'
+    eprintf 'Detected desktop: "%s"\n' "${XDG_CURRENT_DESKTOP}"
+    printf '%s' "${XDG_CURRENT_DESKTOP}"
+}
+
+# get_default_resolution [desktop]
+function get_default_resolution {
+    case "${1}" in
+        'river')
+            local output="$(ristate -o |
+                            jq -r '.outputs | keys.[] as $names |
+                                   {output: $names, focused: .[$names].focused} |
+                                    select(.focused) | .output')"
+            eprintf 'Detected output: %s\n' "${output}"
+            local resolution="$(wlr-randr --json |
+                                jq -r --arg output "${output}" \
+                                 '.[] | select(.name == $output).modes.[] |
+                                  select(.current) | "\(.width)x\(.height)"')"
+            ;;
+        *)
+            die 'unknown desktop session: "%s"' "${1}"
+            ;;
+    esac
+    eprintf 'Detected resolution: %s\n' "${resolution}"
+    printf '%s\n' "${resolution}"
+}
+
+while getopts ':hw:r:d:' OPTOPT; do
+    case "${OPTOPT}" in
+         'h')
+             print_help "${1}"
+             ;;
+         'w')
+             window_manager="${OPTARG}"
+             ;;
+         'r')
+             resolution="${OPTARG}"
+             ;;
+         'd')
+             current_desktop="${OPTARG}"
+             ;;
+         ':')
+             die 'option requires an argument: %s' "${OPTARG}"
+             ;;
+         '?')
+             die 'unknown option: %s' "${OPTARG}"
+             ;;
+    esac
+done
+
+(( "${OPTIND}" > ${#} )) && print_help
+shift $(( "${OPTIND}" - 1))
+
+{
+    set -e
+    [[ -v window_manager ]] ||
+        window_manager='openbox'
+    [[ -v current_desktop ]] ||
+        current_desktop="$(get_current_desktop 2>&3)"
+    [[ -v resolution ]] ||
+        resolution="$(get_default_resolution "${current_desktop}" 2>&3)"
+} 3>&2
+
+function on_sigchld {
+    eprintf 'Xwayland or window manager died! Exiting...\n'
+    kill %sh %Xwayland 2>/dev/null
+    wait ${cat_pid}
+    exit 1
+}
+
+trap on_sigchld CHLD
+
+coproc Xwayland -fullscreen -geometry "${resolution}" -displayfd 1
+local xwayland_display
+read <&p xwayland_display
+export DISPLAY=":${xwayland_display}"
+unset WAYLAND_DISPLAY
+eprintf 'Xwayland display: %s\n' "${DISPLAY}"
+
+cat <&p >&2
+let cat_pid="${!}"
+
+sh -c "exec -- ${window_manager}" &
+
+${@}
+trap -
+kill %sh %Xwayland
+
+wait "${cat_pid}"
+
+eprintf 'Child died! Exiting...\n'