adaptive sync

i3/config

@@ -20,6 +20,11 @@ font pango:NotoSans 12
 # text rendering and scalability on retina/hidpi displays (thanks to pango).
 #font pango:DejaVu Sans Mono 8
 
+# Clear leftover Wayland env (e.g. from a previous Hyprland/sway session) out of
+# systemd/dbus so dbus-activated apps like Thunar don't try to use a dead compositor.
+# Must run before anything dbus-activated starts.
+exec --no-startup-id sh -c "systemctl --user unset-environment WAYLAND_DISPLAY HYPRLAND_INSTANCE_SIGNATURE SWAYSOCK; dbus-update-activation-environment --systemd DISPLAY XAUTHORITY XDG_CURRENT_DESKTOP=i3 XDG_SESSION_TYPE=x11; pkill -x Thunar"
+
 # Start XDG autostart .desktop files using dex. See also
 # https://wiki.archlinux.org/index.php/XDG_Autostart
 exec --no-startup-id dex --autostart --environment i3
@@ -58,6 +63,7 @@ exec --no-startup-id /usr/lib/polkit-gnome/polkit-gnome-authentication-agent-1
 exec --no-startup-id ~/.config/i3/scripts/wallpaper-rotate $wallpaper_dir
 exec --no-startup-id pasystray
 exec --no-startup-id polybar
+exec --no-startup-id ~/.config/i3/scripts/guide-freeze
 
 set $refresh_i3status killall -SIGUSR1 i3status
 
@@ -99,7 +105,7 @@ floating_modifier $mod
 #xrandr --output HDMI-2 --auto --right-of eDP1
 # High refresh rates can flicker on AMD (VRAM clock switching), so run the
 # desktop at 120Hz. See README "High refresh rate flicker".
-exec --no-startup-id xrandr --output DisplayPort-0 --mode 1920x1080 --rate 120
+exec --no-startup-id xrandr --output DisplayPort-0 --mode 1920x1080 --rate 240
 
 # start a terminal
 #bindsym $mod+Return exec i3-sensible-terminal
@@ -108,6 +114,9 @@ bindsym $mod+Return exec $terminal
 # kill focused window
 bindsym $mod+Shift+q kill
 
+# freeze / resume focused window (SIGSTOP / SIGCONT)
+bindsym $mod+m exec --no-startup-id ~/.config/i3/scripts/freeze-toggle
+
 # start dmenu (a program launcher)
 #bindsym $mod+d exec --no-startup-id j4-dmenu-desktop
 #bindsym $mod+d exec --no-startup-id dmenu

i3/scripts/freeze-toggle

@@ -0,0 +1,19 @@
+#!/bin/bash
+# Freeze / resume the focused window's process tree (SIGSTOP / SIGCONT).
+pid=$(xdotool getactivewindow getwindowpid 2>/dev/null) || exit 1
+
+# collect pid plus all descendants (Wine/Proton games spawn several)
+descendants() {
+    local p
+    for p in $(pgrep -P "$1"); do
+        echo "$p"
+        descendants "$p"
+    done
+}
+pids="$pid $(descendants "$pid")"
+name=$(ps -o comm= -p "$pid")
+
+case "$(ps -o state= -p "$pid")" in
+    T*) kill -CONT $pids && notify-send -t 1500 "Resumed" "$name ($pid)" ;;
+    *)  kill -STOP $pids && notify-send -t 1500 "Frozen" "$name ($pid)" ;;
+esac

i3/scripts/guide-freeze

@@ -0,0 +1,50 @@
+#!/usr/bin/env python3
+# Freeze/resume the focused window on the controller's Home/guide button (BTN_MODE).
+# Stdlib only: reads raw evdev events. Gamepads are readable by the seat user.
+import glob, os, select, signal, struct, subprocess, time
+
+EV_KEY, BTN_MODE = 1, 0x13c
+EVENT = struct.Struct('llHHi')  # struct input_event
+LONG_BITS = struct.calcsize('l') * 8
+CMD = [os.path.expanduser('~/.config/i3/scripts/freeze-toggle')]
+
+signal.signal(signal.SIGCHLD, signal.SIG_IGN)  # auto-reap child processes
+
+def has_btn_mode(path):
+    try:
+        with open(f'/sys/class/input/{os.path.basename(path)}/device/capabilities/key') as f:
+            words = f.read().split()
+    except OSError:
+        return False
+    bits = 0
+    for w in words:
+        bits = bits << LONG_BITS | int(w, 16)
+    return bits >> BTN_MODE & 1
+
+fds = {}  # fd -> device path
+last = 0.0
+rescan = 0.0
+while True:
+    if time.monotonic() >= rescan:  # pick up hotplugged controllers
+        for path in glob.glob('/dev/input/event*'):
+            if path not in fds.values() and has_btn_mode(path):
+                try:
+                    fds[os.open(path, os.O_RDONLY)] = path
+                except OSError:
+                    pass
+        rescan = time.monotonic() + 2
+    ready, _, _ = select.select(list(fds), [], [], 2)
+    for fd in ready:
+        try:
+            data = os.read(fd, EVENT.size * 64)
+        except OSError:  # controller unplugged
+            os.close(fd)
+            del fds[fd]
+            continue
+        for sec, usec, type_, code, value in EVENT.iter_unpack(data):
+            if type_ == EV_KEY and code == BTN_MODE and value == 1:
+                now = sec + usec / 1e6
+                if now - last < 0.4:  # GuliKit's Home button double-fires ~10ms apart
+                    continue
+                last = now
+                subprocess.Popen(CMD, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)