Gaze: the hidden panel waits for a command instead of waking every 50 ms

The calibration panel runs for as long as the gaze service does, hidden nearly all the time,
and it woke 20 to 30 times a second to look at its socket and SteamVR's events: about 0.9% of
a core, the main cost left with gaze idle.

It now waits in poll() on its command socket: up to a second while hidden, and up to 10 ms
while shown, as before (it still drains SteamVR's events each pass, so a quit is acknowledged
within a second while hidden). A command wakes it at once, so "show" draws sooner than
before. With --watch-stdin, its stdin closing wakes it as well, so stopping it doesn't wait.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

README.md

@@ -17,6 +17,8 @@ Join the [Frametop Discord](https://discord.gg/W3X9f7z3Bc) for questions, ideas,
 
 ## Install on the headset
 
+> **Frametop doesn't work on the SteamOS beta right now.** On the beta (SteamOS 0.4.3), gaze mode can't read the eye tracker, and the desktop has started without its taskbar ([#15](https://github.com/DeeJanuz/frametop/issues/15)). Use the stable SteamOS release until this note is gone.
+
 You need a Steam Frame with an internet connection, a keyboard (Bluetooth, or the on-screen one), and about 3 GB of free space.
 
 1. In the launcher, choose Launch a program → Desktop.
@@ -58,7 +60,7 @@ If you work in the desktop for long stretches, or leave the headset on a stand,
 | Meta+Shift+H in the desktop | Hides or shows all screens (also in the menu as Hide/Show Screens, and mappable). The Visibility & pins tab of Frametop Display Settings can instead show them only with the dashboard open, or while you look at your wrist |
 | Tap Meta, on any keyboard | Opens the Steam menu in the SteamVR dashboard, or closes the dashboard, wherever you are. The desktop's launcher is still on the taskbar and Alt+F1. Change it in Frametop Input Settings (Keyboard page), where any key combination or modifier tap can do a Frametop or Steam action, open a profile, or run a command of your own |
 | Switch a screen to Hidden (Frametop Display Settings, Visibility & pins → Screens shown) | Hides just that screen until you switch it back, whatever the other visibility settings say; new windows that would open on it float instead |
-| Play a VR game | The screens hide and your controllers stay in the game. Open the SteamVR dashboard, or press Meta+Shift+H, to see and use them. To keep them visible over games, change During VR games on the Visibility & pins tab; the controllers still stay in the game, and you use the screens with the mouse or the dashboard |
+| Play a VR game | Frametop pauses so the game gets the headset to itself (see [Pause for VR games](#pause-for-vr-games)): the screens hide and your controllers stay in the game. Click both thumbsticks together twice to bring Frametop back. With the automatic pause off, the screens still hide, and the SteamVR dashboard or Meta+Shift+H shows them; to keep them visible over games, change During VR games on the Visibility & pins tab |
 
 Restarting the desktop (Restart desktop in Frametop Display Settings) closes its windows, but background work you started in it, such as servers, tmux sessions, or builds, keeps running.
 
@@ -93,6 +95,18 @@ A profile is a named setup: where the screens are, with their sizes and pins, wh
 | Pick a profile under Arrangement and press Open profile | Switches to it: the screens move, open windows of its apps go to their places, and the apps that aren't open start. Nothing closes |
 | Pick a profile under Start in profile, or run its entry (Frametop: NAME) from SteamVR's Launch a program list | The desktop starts in that profile, or switches to it if it's running. A profile can also go on a key combination, mouse button, or controller button in Frametop Input Settings |
 
+### Pause for VR games
+
+Frametop pauses while a VR game runs, so the game gets the headset's CPU and GPU, and comes back a few seconds after the game ends. Paused, the screens hide and the desktop nearly stops drawing, but its windows stay open. Gaze mode's eye tracking stops, and so do remote desktop and hand tracking if they run. The mouse works as a plain mouse in SteamVR.
+
+| Do this | To get this |
+| --- | --- |
+| Click both thumbsticks together, twice | Pauses Frametop, or brings it back, in a game or not. You hear a short sound. The game sees the clicks too |
+| Start a VR game | Frametop pauses, and comes back 5 seconds after the game ends. Bring it back during the game, and it stays on until that game ends |
+| Map Pause/resume Frametop to a mouse button, key combination, or controller button | The same, from that button (Frametop Input Settings) |
+
+The Game optimization page of Frametop Input Settings turns the automatic pause off, changes the gesture, closes the desktop instead of hiding it (more for the game, but its windows close), and turns the sound off. From a terminal: `input/ft-pause on`, `off`, or `status`.
+
 ### Gaze mode (experimental)
 
 In gaze mode the pointer goes where you look, and the mouse or the keyboard does the last bit. The installer offers it (or run `gaze/run.sh install` later), and then our own eye tracker for it, which is more accurate than SteamVR's (or run `gaze/tracker/install.sh` later; it needs `sudo`). Gaze mode uses ours once it's installed, and SteamVR's until then. Turn it on and calibrate it on the Gaze page of Frametop Input Settings.
@@ -122,8 +136,8 @@ This is an early release, tested on one Steam Frame (SteamOS 0.3.0 build 2026092
 
 - A SteamOS or SteamVR update can break parts of it until Frametop catches up. After an update, run `cd ~/frametop && scripts/doctor.sh` in a terminal. It checks what Frametop needs from SteamOS, and says what changed since the versions you last marked as working and what to try. Once everything works, `scripts/doctor.sh --mark-good` records the versions. If something stops working, please report it.
 - The first install downloads 1–2 GB for the build container and compiles everything on the headset, which takes several minutes.
-- During a VR game you can't show the screens with a controller button, because the game owns the buttons. Open the SteamVR dashboard, press Meta+Shift+H, or use a mapped mouse button instead.
+- During a VR game, mapped controller buttons belong to the game, so they can't bring the screens up. The pause gesture still works: Frametop reads it without taking the thumbsticks from the game. With the automatic pause off, open the SteamVR dashboard, press Meta+Shift+H, or use a mapped mouse button instead.
-- Flatscreen games aren't detected as games. If your controllers end up working the screens instead of the game, set Controllers on the screens to "Only with the SteamVR dashboard open" (Frametop Display Settings, Visibility & pins tab).
+- Flatscreen games aren't detected as games, so they don't pause Frametop by themselves: click both thumbsticks twice to pause it. If your controllers end up working the screens instead of the game, set Controllers on the screens to "Only with the SteamVR dashboard open" (Frametop Display Settings, Visibility & pins tab).
 - Typing follows your last click. A controller click on a panel other than the screens (the dashboard, a Steam app) doesn't move typing there; click it with the mouse, or click a screen to bring typing back.
 - The screens don't draw a mouse cursor of their own. The 3D mouse's dot or SteamVR's laser shows where you're pointing.
 - Profiles reopen apps, not what the apps had open. Tabs, files, and folders are left to each app's own restore.

display-settings/main.qml

@@ -802,7 +802,7 @@ Kirigami.ApplicationWindow {
                     Repeater {
                         model: [
                             { value: "hide", text: "Hide them unless the SteamVR dashboard is open", help: "The game has the view to itself; open the dashboard (or press Meta+Shift+H) to see the screens." },
-                            { value: "visible", text: "Keep them visible over the game", help: "They float over the game as they are outside it." }
+                            { value: "visible", text: "Keep them visible over the game", help: "They float over the game as they are outside it. Turn off Pause while a VR game runs in Frametop Input Settings (Game optimization), or Frametop pauses and hides them anyway." }
                         ]
                         delegate: ColumnLayout {
                             required property var modelData

docs/design.md

@@ -189,6 +189,15 @@ Movement is judged within 10-second windows. On the mount, the head pose jittere
 
 Staying awake while charging uses Steam's own setting rather than a logind sleep inhibitor. Steam suspends with `dbus-send ... login1.Manager.Suspend boolean:true`, and a block inhibitor does stop that (`CanSuspend` answers "challenge" while one is held), but it stops the power button too. `system_idle_suspend_ac_sec` is field 24004 of Steam's CMsgClientSettings. In Steam's SharedJSContext, reachable over CDP on port 8080 because Steam runs with `-cef-enable-debugging`, `SteamClient.Settings.SetSetting` takes a change as a base64 protobuf, the way Steam's Power page sends it (0 is never), and `settingsStore.clientSettings` has the current values.
 
+## Pausing for VR games
+
+Hiding the screens during a game kept them out of view, but Frametop kept using the headset. Measured on 2026-10-02 with gaze mode off and no game running, in shares of one core: our eye tracker (ft-eyes) about 60%, ft-eyegrab, ft-gaze and ft-gazed about 3 to 4% each; remote desktop (krdpserver, FreeRDP, Xvnc) about 2 cores while it ran; KWin about 13%, ft-screens about 4%. The gaze service ran at full rate whether gaze mode was on or not; now it idles while the gaze isn't used (gaze/README.md), and pausing stops it outright. Reading SteamVR's eye tracking 90 times a second also made it restart every 10 to 13 seconds during Beat Saber, and each restart took input focus from the game, which paused it (PR #13; since then ft-gaze skips SteamVR's gaze action during games, but our own tracker kept running). So pausing stops what costs the most and leaves windows where they are.
+
+- A hidden screen still cost as much as a visible one. ft-screens sent every committed screen its frame callback at 90 Hz whether its overlay showed or not, so KWin kept drawing, and its apps with it. Paused, ft-screens sends the callbacks once a second. A Wayland client draws again only after its last frame's callback, so KWin's output stalls, KWin's own clients stop getting theirs, and the whole desktop idles, without anything losing its connection. A second's pace, rather than none, keeps any client that waits on a callback from waiting forever. Stopping KWin or the apps with SIGSTOP would free the same, but a Wayland peer that stops reading overflows the other side's 4 KB socket buffer, which ends the connection: that's how the live desktop died once when its KWin stalled (`Data too big for buffer`). They also sit in different cgroups (KWin under steam.service when the VR launcher starts it, ft-screens in the dev container's), so no single freeze stops them together.
+- The relay does the pausing because it's the one part that always runs, and the pointer helper keeps running because stopping it leaves its virtual controller connected with its last pose (the driver has no staleness timeout), maybe holding a hand role, with the 3D mouse dead. Releasing it does the job. The helper already checks for a scene app twice a second, so it's what tells the relay a game started.
+- The gesture has to work during a game, but SteamVR input reaches only the app with input focus, and an overlay with global input (`steamvr/globalActionSetPriority`) takes the buttons it binds from the game. vrserver's web socket on 127.0.0.1:27062, which its controller binding page uses for the live view, reports every controller component whatever has focus, and reading it takes nothing. The game sees the clicks too, so the default is a gesture games hardly use: both thumbsticks, together, twice. "Together" means within 0.3 seconds of each other, so a stick held down to sprint while the other clicks doesn't count. The stream is about 160 messages a second, nearly all capacitive sensing, so the reader parses only the few that mention a gesture's button. A controller's root path changes while the 3D mouse holds its hand role (`/devices/cv/<serial>` instead of `/user/hand/right`), so the reader looks the controllers up again every 3 seconds.
+- Resuming starts remote desktop through `systemd-run --scope`: started straight from the relay, it would join the relay's cgroup and end with the next relay restart.
+
 ## SteamOS updates
 
 On the Frame, SteamVR is part of the OS image (`/opt/steamvr`, the `deckard-steamvr-rel` package), next to KWin, gamescope, and the kernel, so every SteamOS update can bring a new SteamVR too. Frametop survives updates: it lives in the home folder and the `dev` container, the Bluetooth fixes are in `/etc`, which SteamOS keeps across updates, and nothing goes into `/usr`. What an update can break is what Frametop uses from the image. The public OpenVR API is versioned and stays put. The rest is less certain: `IVRIPCResourceManagerClient`, which is newer than the header SteamVR ships; the text `vrcmd --overlays` prints; the eye tracker's shared memory layout; XRService's camera buffers; KWin's nested backend; and behavior Frametop works around, such as the SteamVR Settings page that `ComputeOverlayIntersection` can't find or the scale KWin's nested backend doesn't undo.

docs/profiles.md

@@ -46,8 +46,8 @@ So a "Work" profile can put three screens around you with a browser, two termina
 
 ## How it works
 
-- **Capture** (`ft-layout save NAME`, and Save as profile… in Display Settings). ft-layout captures the screens as before, then asks ft-floatd for the windows (`windows` on @frametop_float). ft-floatd has the KWin script report every window as it is now (`report-all`), then answers with every normal window: its desktop file name, the screen it's on, its rectangle there, and whether it's maximized. For floating windows it gives their panel's place, their size in pixels, and their scale. Windows with no desktop file name are kept by their process's command line (`/proc/<pid>/cmdline`) and window class. Windows of Plasma itself, the Frametop settings apps, and dialogs aren't recorded. If ft-floatd doesn't answer, the profile keeps the apps it had.
+- **Capture** (`ft-layout save NAME`, and Save as profile… in Display Settings). ft-layout captures the screens as before, then asks ft-floatd for the windows (`windows` on @frametop_float). ft-floatd has the KWin script report every window as it is now (`report-all`), then answers with every normal window: its desktop file name, the screen it's on, its rectangle there, and whether it's maximized. For floating windows it gives their panel's place, their size in pixels, and their scale. A window whose app id has no desktop file (a Flatpak app's X11 window can give its own: RustDesk's says `com.carriez.flutter_hbb`, its desktop file is `com.rustdesk.RustDesk`) is kept by the desktop file whose `StartupWMClass` names its window class. Windows with no desktop file name are kept by their process's command line (`/proc/<pid>/cmdline`) and window class. Windows of Plasma itself, the Frametop settings apps, and dialogs aren't recorded. If ft-floatd doesn't answer, the profile keeps the apps it had.
-- **Apply** (`ft-layout use NAME`, Open profile in Display Settings). ft-layout makes the profile's hidden screens the screens' own setting, arranges the screens (which hides and shows them: ft-screens' `conceal` and `reveal`), then has ft-floatd open the apps (`profile NAME`; ft-floatd reads the windows from the layout file). If the screens can't be arranged, for example with the headset off and no head pose, the apps still open: the screens stay where they are, the profile's hidden screens still hide, and floating windows go relative to the screens wherever they are. ft-floatd goes through the entries app by app. It claims windows of that app already open (oldest first, each claimed once), and moves each to its entry's place: onto its screen at its rect (or maximized), or floating at its pose. For the entries left over, it launches the app once (`ft-float launch`, the same path as Launch as Standalone) and waits up to 30 seconds for its first window. Each window that shows up goes to the next entry's place. Once the first window has been up for 3 seconds (time for an app that restores its own windows to show them), ft-floatd launches the app again for each entry still waiting, and waits up to 30 seconds more. New windows are matched to the launch by process (or a child of it), or by desktop file name: single-instance and D-Bus-activated apps open their windows from a process that was already running.
+- **Apply** (`ft-layout use NAME`, Open profile in Display Settings). ft-layout makes the profile's hidden screens the screens' own setting, arranges the screens (which hides and shows them: ft-screens' `conceal` and `reveal`), then has ft-floatd open the apps (`profile NAME`; ft-floatd reads the windows from the layout file). If the screens can't be arranged, for example with the headset off and no head pose, the apps still open: the screens stay where they are, the profile's hidden screens still hide, and floating windows go relative to the screens wherever they are. ft-floatd goes through the entries app by app. It claims windows of that app already open (oldest first, each claimed once), and moves each to its entry's place: onto its screen at its rect (or maximized), or floating at its pose. For the entries left over, it launches the app once (`ft-float launch`, the same path as Launch as Standalone) and waits up to 30 seconds for its first window. Each window that shows up goes to the next entry's place. Once the first window has been up for 3 seconds (time for an app that restores its own windows to show them), ft-floatd launches the app again for each entry still waiting, and waits up to 30 seconds more. New windows are matched to the launch by process (or a child of it), or by desktop file name (found the same way as at capture): single-instance and D-Bus-activated apps open their windows from a process that was already running.
 - **Default at start.** The session script runs `ft-layout start --wait 90`. That opens the profile in `FT_PROFILE` or `default_profile` (screens, then the apps once ft-floatd is up), or runs `apply --wait` if there's none. Start in profile on the Layout & profiles page sets `default_profile` (`ft-layout default NAME|none`). Plasma's session restore is turned off in the session (`ksmserverrc`: `loginMode=emptySession`).
 - **Launcher entries.** Each profile gets `~/.local/share/applications/frametop-profile-<name>.desktop` ("Frametop: Work"), written when it's saved and removed when it's deleted. They show in SteamVR's Launch a program list, the Application Launcher, and KRunner. Running one (`ft-layout open NAME`) switches to that profile if the desktop runs. Otherwise it starts the desktop with `FT_PROFILE` set (`systemd-run`, as `desktops.sh start` does), which overrides `default_profile` for that start. That needs SteamVR to be running.
 - **The action.** `profile:NAME` in the input relay (it runs `ft-layout use NAME`) for key combinations, mouse buttons, and controller buttons, with or without pointer mode. Input Settings lists one "Open profile NAME" action per profile.

docs/reference.md

@@ -66,12 +66,12 @@ place N x y z yaw pitch roll     width N metres          curve N radius|on|off
 pin N|all left|right|head [matrix]    unpin N|all        size N w h
 get N    screens    head    state    key code value    scale N s    vrkeyboard show|hide|toggle|close
 visibility always|dashboard|gesture|toggle    wrist degrees    gesture left|right degrees
-hide | show | toggle    controllers always|outside_games|dashboard    ingames hide|visible
+hide | show | toggle    controllers always|outside_games|dashboard    ingames hide|visible    pause on|off|state
 conceal N|all    reveal N|all    concealed    cutouts on|off|state    cutouts predict on|off    cutouts lead ms
 float N mpp x y w h title    unfloat N    pose N matrix    sub N k x y w h | sub N k off    minimized N 0|1    carry N
 ```
 
-`conceal` and `reveal` hide and show one screen on its own (`ft-layout hide` and `show` send them), and `concealed` lists those screens. `cutouts` turns the hand cutouts on and off (`ft-handsctl cutouts`). The last line is ft-floatd's, for floating windows: N is a floating window's panel, numbered on from the screens, one per spare output. `float` gives the window's rectangle in its output, metres per pixel, and the title bar's height, and shows the panel; `unfloat` hides it. `pose` places it (a 3x4 matrix, standing universe), `sub` shows popup or dialog k over it, `minimized` hides it while its window is minimized, and `carry` moves it with the laser that pressed the window's own title bar.
+`conceal` and `reveal` hide and show one screen on its own (`ft-layout hide` and `show` send them), and `concealed` lists those screens. `pause on` (from the input relay, when Frametop pauses for a VR game) hides every screen and floating window whatever else says, and slows the desktop down; `pause off` undoes it. `cutouts` turns the hand cutouts on and off (`ft-handsctl cutouts`). The last line is ft-floatd's, for floating windows: N is a floating window's panel, numbered on from the screens, one per spare output. `float` gives the window's rectangle in its output, metres per pixel, and the title bar's height, and shows the panel; `unfloat` hides it. `pose` places it (a 3x4 matrix, standing universe), `sub` shows popup or dialog k over it, `minimized` hides it while its window is minimized, and `carry` moves it with the laser that pressed the window's own title bar.
 
 ## Input relay
 
@@ -114,11 +114,12 @@ The pointer settings are in `~/.config/frametop.conf`: `POINTER_SENSITIVITY`, `P
 
 ## Frametop Input Settings
 
-A Kirigami app with a Python backend, in the Plasma menu under Settings. It runs in the `dev` container and talks to the relay over its control socket, `@frametop_relay`. It has eight pages:
+A Kirigami app with a Python backend, in the Plasma menu under Settings. It runs in the `dev` container and talks to the relay over its control socket, `@frametop_relay`. It has nine pages:
 
 - Devices lists every USB and Bluetooth mouse and keyboard, with a light that flashes when the device is used. Each device gets a role: 3D pointer (grabbed, drives the pointer; the default for anything with a mouse), Pass through (grabbed only while typing goes to the desktop; the default for keyboards, whose key combinations work everywhere), or Ignore. A device is identified by its Bluetooth address, or its USB ids and name, so all of its input nodes share one role. Forget drops everything saved for a device.
-- Buttons maps a pointer device's buttons. Choose Capture a button, press the button or key, then pick an action: a click, back, scroll, toggle dashboard, recenter, pointer on or off, head follow on or off, gaze pointer on or off, gaze precision, gaze drag, gaze quick check, faster or slower, reset the screen layout, hide or show the screens, open or close the keyboard, float a window in VR or put it back, put all floating windows back, Open profile NAME (one per profile, [profiles.md](profiles.md)), pass the key through, or nothing. Devices with saved mappings are listed even while they're asleep.
+- Buttons maps a pointer device's buttons. Choose Capture a button, press the button or key, then pick an action: a click, back, scroll, toggle dashboard, recenter, pointer on or off, head follow on or off, gaze pointer on or off, gaze precision, gaze drag, gaze quick check, faster or slower, reset the screen layout, hide or show the screens, open or close the keyboard, float a window in VR or put it back, put all floating windows back, pause or resume Frametop ([Pausing for VR games](#pausing-for-vr-games)), Open profile NAME (one per profile, [profiles.md](profiles.md)), pass the key through, or nothing. Devices with saved mappings are listed even while they're asleep.
 - Controllers maps the Frame controllers' buttons (every button but the system button) to the same actions, except passing a key through and the gaze actions: gaze mode is a mouse and keyboard feature ([gaze-controllers.md](gaze-controllers.md)). Capture a button and press it on a controller, or pick it from the list. The controllers aren't input devices on the host; only SteamVR sees them. So the pointer helper reads them with SteamVR input (`pointer/helper/vrbuttons.h`, `pointer/helper/actions/`) and sends presses to the relay (`vrbtn right/a 1`), which does the mapped action. The helper only takes the buttons that are mapped (the relay tells it with `vrbind`), at an overlay-global priority, and only while no game (scene application) runs, so games keep every button; with In games on (`controller_in_games`), a mapped button is taken from games too. That needs SteamVR's "Enable global input from overlays (Experimental)" setting (`steamvr/globalActionSetPriority`), which the page's Global input switch turns on and off. Mappings are saved as `controller_buttons` in `~/.config/frametop-input.json`.
+- Game optimization has the pause for VR games: its state with Pause now or Resume, whether VR games pause Frametop by themselves, the controller gesture (one or two buttons, pressed once or twice; one button always takes two presses), what happens to the desktop, and the sound. They're saved as `pause_auto`, `pause_gesture`, `pause_desktop`, and `pause_sound` in `~/.config/frametop-input.json`. See [Pausing for VR games](#pausing-for-vr-games).
 - Keyboard sets when Frametop's keyboard opens: whenever a text field is selected; only while no pass-through keyboard is connected (the default; keyboards other programs make through uinput, like frame-voice's, don't count); only with a mouse or controller button mapped to Open/close keyboard; or never, which turns the button off too. Keep it open (on by default, `vr_keyboard_persist`) leaves it open after the text field loses focus. The mode is saved as `vr_keyboard` in `~/.config/frametop-input.json`, and the page lists the keyboards that count as connected. Its Key combinations section maps modifiers plus a key, or one modifier tapped on its own, on any keyboard, to any action but passing a key through or nothing, or to Run a command…: a command line the input relay runs with `sh -c` when you press the keys (`command:CMD`). The command runs as the relay's user service, outside the desktop's session, with `layout/`, `float/` and `steam/` on its `PATH` (so `ft-layout use Work` or `ft-float launch org.kde.dolphin` work as they are), and its output goes to the relay's journal. The gaze clicks (Gaze left click and Gaze right click) only go on key combinations. The defaults are a Meta tap (open the Steam menu, or close the dashboard), Meta+J (gaze left click), Meta+K (gaze right click), and Meta+Shift+F (float window in VR or put it back); remove them or add others there. A tap is a press and release with no other key, mouse button, or scroll in between; a bound one sends the desktop F24 before the release, so Plasma's launcher doesn't open on it. The combination's last key isn't typed, and the modifiers still reach the app; while typing goes to Steam rather than the desktop, keyboards aren't grabbed, so Steam or the game sees the keys too. They're saved as `key_bindings` in the same file; a file with its own list, even an empty one, gets no defaults.
 - Pointer has a Head follow switch and sliders for the pointer settings, which apply immediately, and a Recenter button.
 - Ignored panels lists the SteamVR overlays that are showing, grouped by app (the first two parts of the overlay key, such as `sasaken.frame-perf-overlay`), from the pointer helper (`overlays`). Tick a panel, or Ignore the whole app, and the pointer passes through it to what's behind. It's for panels you only look at, like a performance overlay that follows your view. The list is saved as `POINTER_IGNORE` in `~/.config/frametop.conf`: comma-separated overlay keys, where a shell pattern like `vendor.app*` covers a whole app, including panels it opens later. The helper reloads at once. Frametop's own screens aren't listed, and entries for apps that aren't open are listed below, to remove.
@@ -199,9 +200,36 @@ power/run.sh off | on      # the displays off now, or back on
 power/run.sh log
 ```
 
+## Pausing for VR games
+
+Paused, Frametop leaves the headset's CPU and GPU to a VR game. The input relay does it (`input/game_pause.py`), since it's the one part that always runs:
+
+- The gaze service stops (`frametop-gaze`: ft-gazed, ft-gaze, our own eye tracker, the gaze panel), so nothing reads SteamVR's eye tracking. Our frame grabber, the root service `ft-eyegrab`, goes idle by itself 3 seconds after our eye tracker stops asking it for frames.
+- Hand tracking stops if it runs (`frametop-camd`, `frametop-hands`).
+- The desktop, as the Game optimization page of Frametop Input Settings says (`pause_desktop`): hidden (the default) or closed. Hidden, ft-screens hides every screen and floating window whatever the visibility mode, the hotkey, or the dashboard says, and gives KWin a frame callback once a second instead of 90 times. KWin draws a screen only after its frame callback, and its apps wait for theirs, so the desktop hardly draws, but its windows stay open. Remote desktop stops if it runs (`session/remote-ctl.sh`). Closed, `desktops.sh stop` closes the desktop and its windows, and resuming starts it again (about 12 seconds), in its start profile if it has one.
+- The relay lets go of the 3D mouse and feeds pointer devices to its virtual mouse and keyboard, as with `POINTER=0`. Typing goes to Steam. Mapped buttons and key combinations do nothing but pausing, the Steam menu, and commands; a key combination that does nothing is typed as usual.
+
+Resuming starts again only what pausing stopped, and plays a second sound. The pointer helper and ft-powerd keep running: they cost little, the helper is what says a game started, and stopping it would leave its virtual controller connected with its last pose.
+
+Ways to pause and resume:
+
+- The controller gesture, by default both thumbsticks clicked together twice: both go down within 0.3 seconds of each other, and the second time within 0.7 seconds of the first. The relay reads it from vrserver's web socket (`input/vrws.py`), which works whatever has input focus and takes nothing from the game, so the game sees the clicks too. The Game optimization page changes it: one or two of the buttons the Controllers page lists, pressed once or twice (one button always takes two), or none.
+- The Pause/resume Frametop action, on a mouse button, a key combination, or a controller button (outside games, like every mapped controller button).
+- VR games, with Pause while a VR game runs on (`pause_auto`, the default). The pointer helper tells the relay when a scene app starts and ends (`vrgame 1|0`, repeated every 5 seconds). A game starting pauses Frametop. A pause that starts while a game runs ends 5 seconds after the game does, unless another game starts first. Resumed during a game, Frametop stays on until that game ends. A pause that starts outside a game lasts until you resume. Flatscreen games aren't scene apps, so they don't pause it.
+- From a terminal or a script:
+
+```
+input/ft-pause on | off | toggle   # pause or resume
+input/ft-pause status              # the state as JSON (the relay's "pause ?")
+input/vrws.py 10                   # the controllers' buttons from vrserver's web socket, for 10 s
+input/test/pause-test.py           # the gesture and the automatic pause, offline
+```
+
+The state outlives a relay restart, in `/run/user/UID/frametop-pause.json`. A SteamVR restart while paused starts the gaze service with it, and the relay stops it again when the pointer helper comes back.
+
 ## Gaze pointer (experimental)
 
-In gaze mode the 3D mouse's pointer goes where you look, and the mouse or the keyboard does the last bit. It needs the gaze service, which `install.sh` offers (yes by default) and `gaze/run.sh install` installs on its own: it builds it and runs `gaze/ft-gazed` as `frametop-gaze.service`, which starts with SteamVR. Turn gaze mode on with the Gaze page of Frametop Input Settings, `gaze/ft-gazectl on`, `POINTER_GAZE=1`, or a button or key combination mapped to Gaze pointer on/off.
+In gaze mode the 3D mouse's pointer goes where you look, and the mouse or the keyboard does the last bit. It needs the gaze service, which `install.sh` offers (yes by default) and `gaze/run.sh install` installs on its own: it builds it and runs `gaze/ft-gazed` as `frametop-gaze.service`, which starts with SteamVR. The service idles while the gaze isn't used: its eye tracker reader and our own eye tracker run only while gaze mode is on and someone wears the headset, while a check or the calibration runs, or while the Gaze page of Frametop Input Settings is open, and stop 30 seconds after ([gaze/README.md](../gaze/README.md)). Turn gaze mode on with the Gaze page of Frametop Input Settings, `gaze/ft-gazectl on`, `POINTER_GAZE=1`, or a button or key combination mapped to Gaze pointer on/off.
 
 - Meta+J left-clicks and Meta+K right-clicks where you look. A quick tap clicks where the dot was at the press. Hold instead, and the dot stays put in your view: turn your head until it's on what you meant, and let go to click there. Held still for `POINTER_GAZE_HOLD` (0.5 s), the press becomes a real one, and your head drags. Meta+K with Meta+J held presses where the dot is now, to drag from there, and a second Meta+K during that drag (a double Meta+K) pans and tilts what you're dragging while it's held.
 - The mouse's buttons work the same way, with the mouse steering instead of your head (`POINTER_GAZE_MOUSE=precision`, the default): the right button with the left held starts a drag, and a double right click pans and tilts what you're dragging. With `POINTER_GAZE_MOUSE_MOVE=held`, the default, the mouse only corrects: while the gaze has the pointer, moving it does nothing unless a button is held. `free` lets the mouse take the pointer any time. With the gaze stale for a second, in a game, or with the headset off, the mouse works as usual.

float/ft_floatd.py

@@ -229,6 +229,24 @@ def cmdline(pid):
         return []
 
 
+def desktop_name(app, cls):
+    """The desktop file name for a window's app id and class. A Flatpak app's window can give an
+    id with no desktop file: RustDesk's (an X11 window) says com.carriez.flutter_hbb, and its
+    desktop file is com.rustdesk.RustDesk. That file's StartupWMClass names the window's class
+    then. The app id itself when nothing matches."""
+    try:
+        if not app or Gio.DesktopAppInfo.new(app + ".desktop"):
+            return app
+    except TypeError:  # PyGObject raises for the NULL a missing desktop file returns
+        pass
+    names = {n.lower() for n in (app, cls) if n}
+    for info in Gio.AppInfo.get_all():
+        wm = info.get_startup_wm_class() if isinstance(info, Gio.DesktopAppInfo) else None
+        if wm and wm.lower() in names:
+            return info.get_id().removesuffix(".desktop")
+    return app
+
+
 class Launch:
     """An app we started: its first window floats, or (for a profile) its windows go to the
     profile's entries for it, in order."""
@@ -745,7 +763,10 @@ class Daemon:
         Returns (reply, pid or None)."""
         if app:
             app = app.removesuffix(".desktop")
-            info = Gio.DesktopAppInfo.new(app + ".desktop")
+            try:
+                info = Gio.DesktopAppInfo.new(app + ".desktop")
+            except TypeError:  # PyGObject raises for the NULL a missing desktop file returns
+                info = None
             if info is None:
                 return f"error no app {app}", None
             pids = []
@@ -776,8 +797,10 @@ class Daemon:
             return None
         chain = pid_chain(int(ev.get("pid") or 0))
         app = ev.get("app", "")
+        # (An X11 window in a Flatpak gives its pid in the sandbox: only its app id can match.)
+        apps = {app, desktop_name(app, ev.get("cls", ""))} if app and any(la.app for la in self.launches) else {app}
         for la in self.launches:
-            if any(p in chain for p in la.pids) or (la.app and app and la.app == app):
+            if any(p in chain for p in la.pids) or (la.app and app and la.app in apps):
                 if not la.entries or len(la.entries) <= 1:
                     self.launches.remove(la)
                 return la
@@ -841,7 +864,7 @@ class Daemon:
         for wid, ev in self.windows.items():
             if not recordable(ev):
                 continue
-            entry = {"app": ev["app"]} if ev.get("app") else {"cmd": cmdline(ev.get("pid")), "class": ev.get("cls", "")}
+            entry = {"app": desktop_name(ev["app"], ev.get("cls", ""))} if ev.get("app") else {"cmd": cmdline(ev.get("pid")), "class": ev.get("cls", "")}
             if not entry.get("app") and not entry.get("cmd"):
                 continue
             f = self.floats.get(wid)
@@ -868,7 +891,7 @@ class Daemon:
         return out
 
     def window_key(self, ev):
-        return ev.get("app") or json.dumps(cmdline(ev.get("pid")))
+        return desktop_name(ev.get("app", ""), ev.get("cls", "")) or json.dumps(cmdline(ev.get("pid")))
 
     def open_profile(self, name):
         """Open a profile's apps (additive: nothing closes)."""
@@ -884,9 +907,9 @@ class Daemon:
             if key != "[]":
                 groups.setdefault(key, []).append(e)
         claimed = set()
+        keys = {wid: self.window_key(ev) for wid, ev in self.windows.items() if recordable(ev)}
         for key, entries in groups.items():
-            have = [ev for wid, ev in self.windows.items()
+            have = [ev for wid, ev in self.windows.items() if wid not in claimed and keys.get(wid) == key]
-                    if wid not in claimed and recordable(ev) and self.window_key(ev) == key]
             for e, ev in zip(entries, have):
                 claimed.add(ev["id"])
                 self.place_entry(ev, e)

gaze/README.md

@@ -2,7 +2,7 @@
 
 The Steam Frame's eye tracking as pointer input: a gaze mode for the 3D mouse (the pointer goes where you look, and the mouse does the last bit), and the tools to calibrate and measure it.
 
-- `ft-gaze` (C++, OpenVR, runs in the dev container) reads the eye tracker and prints one JSON line per sample (90 Hz). For each source, it gives the gaze direction relative to the head and the Frametop screen pixel it lands on.
+- `ft-gaze` (C++, OpenVR, runs in the dev container) reads the eye tracker and prints one JSON line per sample (90 Hz). For each source, it gives the gaze direction relative to the head and the Frametop screen pixel it lands on. The gaze service asks it for only the sources it uses (`--sources`, and `sources LIST` on its stdin): our tracker and mmap set 1 with Own tracker, about 700 bytes a line instead of 1.3 KB, and every source while a check or the calibration runs. So SteamVR's gaze action, the only source that calls into vrserver (twice a sample), is read only then. The probe gets them all.
 - `gazecal.py` has what the probe and the gaze service share: the correction models, filters, and the reader for SteamVR's eye tracking log.
 - `tracker/` is our own eye tracker, an alternative to SteamVR's: `ft-eyes` finds the pupils and glints in the eye-camera frames that `ft-eyegrab` (a small root service) copies out of SteamVR's tracker. See "Our own eye tracker" below.
 - `probe/ft-gazeprobe` (GTK 4, host Python) is a fullscreen playground, for developing the gaze tracking: day to day, the calibration and the checks run in the headset panel (Quick check, Calibrate, and Check headset fit on the Gaze page). It runs ft-gaze, draws where you're looking, measures accuracy, and tries out hold-to-adjust clicking with a calibration that learns from your adjustments.
@@ -35,6 +35,7 @@ Gaze as an input method for the whole desktop, without replacing anything of Ste
 - **Learning from nudges:** if the mouse took the pointer from the gaze and moved it (0.2 degrees or more, and the correction within `POINTER_GAZE_NUDGE_MAX`: 55 degrees by default, half of the 109 the headset shows across, and 1 to 110; the same limit for mouse, keyboard, and pinch clicks) before you clicked, or you dragged a held press that far, you were nudging it onto what you looked at. The helper sends that as a lesson, from the raw gaze when the mouse took over to where you clicked, and ft-gazed learns it. So using it is what calibrates it. The raw gaze is one ft-gazed sent, so it also finds when that look was, and what each eye read then. With SteamVR, each eye learns its own error. With our tracker, the look goes to it as a click, like the probe's, and it relearns how the headset sits on your face. After the headset was off, your first nudge and click there resets that (the quick check's dot does the same). A correction past `POINTER_GAZE_NUDGE_MAX` isn't learned: the helper asks ft-gazed for the quick check instead ("recheck", after its 2-minute cooldown). Tested on our tracker's 409 clicks since its Sep 29 calibration: a one-dot check set from any one of them put the next 2 minutes' clicks within 15 degrees (99% within 4.2) and the next 10 minutes' within 25 (the far ones after the headset moved), so the check gets back well under it. The limit used to be 8 degrees, and live on 2026-10-01 our tracker was 12 off after the headset went on, so every correction was dropped. One lesson moves the whole correction by only a third of what it measured (more near where it was taken), since in the first live test one 6 degree lesson moved everything and put the next target 7 degrees off. `ft-gazectl status` shows the lessons, and `ft-gazectl forget` drops them.
 - **Checks and calibration in the headset** (`gaze/gazecheck.py`, shown by `gaze/panel/ft-gazepanel`, a panel fixed to the headset that ft-gazed runs): a one-dot quick check opens when you put the headset on (SteamVR's tracker sees your eyes for 3 s after none for 3 s; its "HMD on" log line can't say, since it repeats every minute or so and can stay on for hours with nobody in the headset), when our tracker asks for a click (its "reseat", when the headset may sit differently), at most once every 2 minutes, and from Quick check on the Gaze page. Look at the dot: it takes your gaze once it has held still for 0.6 s (the steadiness counts, not where the tracker puts it, so it works however far off it is), or at once with a left click or Meta+J; a right click or Meta+K closes it, and ignoring it changes nothing. It also runs when a click's correction was past `POINTER_GAZE_NUDGE_MAX`. The dot is still and the ring fills in quarters, so the panel is drawn again only a few times per dot. If the first 3 lessons after it are still over 2 degrees off, five dots follow. The full calibration (Calibrate on the Gaze page, or by itself whenever gaze mode is on without one and your eyes are seen) is the probe's: three rounds, dark, medium and bright, of the middle and a ring around it, in a panel 64 degrees wide, with Frametop's screens hidden. Its dots (and the five-dot check's) wait for a click: look at the dot and left click or press Meta+J, and the gaze held still up to then is taken. A dot that isn't taken says why, on an orange line over the instructions: with SteamVR's tracker, what dropped most of that look's samples (an eye lost, a blink, the two eyes disagreeing); with ours, its reply (an eye seen in too few frames, or moving). A dot gets two tries, then it's skipped. A calibration left with under two thirds of its dots fails and names the most common reason, as the Gaze page does after it. A click that has taken nothing after 1.5 s says what it waits for: the gaze to hold still, or an eye tracker that isn't sending. Capturing whenever the gaze held still sometimes took a look that wasn't on the dot. The panel draws into three shared buffers SteamVR imported once, as Frametop's keyboard does: uploading each picture anew (SetOverlayRaw) flickered, and in one live test left the headset showing an old picture. Quitting it while there's still no calibration turns gaze mode off; turning it on again reopens it. One that closes otherwise unfinished (ignored for 2 minutes, too few dots) opens again after the headset comes off and on. Why gaze mode, on, can't work yet goes in the service's status as `checks.problem`, which the Gaze page shows under the Gaze pointer switch. For our tracker a check is a click and the calibration is its own (calib-point per dot); for SteamVR's, a check is a lesson for each eye and the calibration replaces calibration.json, and the lessons start over. Checks go to `checks.jsonl`.
 - Nothing writes to SteamVR, its eye tracker, or its files: ft-gaze maps the eye tracker's shared memory read-only. With no fresh gaze (a blink, the service stopped, the headset off), the pointer stays where it is, and the mouse works as always.
+- **Idle while the gaze isn't used:** ft-gaze and our own tracker run only while gaze mode is on and someone wears the headset (the pointer helper says both: SteamVR drops the headset's activity level as soon as it comes off), while a check or the calibration is open or asked for, or while the Gaze page of Frametop Input Settings is open (it renews a `wake` lease). 30 seconds after the last use they stop, and our frame grabber goes idle with our tracker. With our tracker, that saves over half a core: on 2026-10-02, with gaze mode off, ft-eyes took about 60% of a core, and ft-eyegrab, ft-gaze and ft-gazed 3 to 4% each. A check asked for while it idles starts the tracker and opens once it sends. When the gaze is used again, it takes a few seconds to come back, and our tracker's first click re-seats it, as after the headset was off: so the quick check opens when gaze mode comes on after the service idled, as it does when you put the headset on. `ft-gazectl status` says `"awake"`, and `"idle"` says why it isn't. A stand that covers the proximity sensor makes the headset seem worn, so with gaze mode on it doesn't idle there.
 
 Lessons are logged to `pointer-lessons.jsonl`: the raw gaze, the true direction, the correction at the time, and how far off it was.
 
@@ -62,7 +63,7 @@ Ground rules, for anyone changing it:
 - **Clean room.** Nothing of Valve's goes in: we don't decompile, disassemble, or patch the `eyetracking` binary or its network weights, and we don't copy their code or weights. Its public output (eye-server.mmap, read-only) is fair game as a baseline and as labels, and so are published papers and openly licensed pupil detectors (check each one's license: PuRe, PuReST, ElSe, and ExCuSe are non-commercial only).
 - **Root only reads.** ft-eyegrab never writes to, stops, or signals the `eyetracking` process, vrserver, or vrcompositor, never opens `/dev/adsp`, `/dev/cdsp`, or `/dev/spidev0.1`, and never writes to `/dev/shm/eye-server.mmap` (it also carries calibration clicks into SteamVR's tracker), `/opt`, or `/persist`.
 - **Eye images are biometric data.** Recordings live outside the repo, in `~/.local/share/frametop/eyes/captures` (0700), and `.gitignore` catches stray frame dumps. They go nowhere but the machine that runs your offline jobs.
-- **Mind the headset's budget.** Finding a pupil takes about 0.4 ms a frame while ft-eyes follows it, and 1.4-2.1 ms when it searches the whole frame. Replays, scoring, and training go to a PC.
+- **Mind the headset's budget.** Finding a pupil takes about 0.4 ms a frame while ft-eyes follows it, and 1.4-2.1 ms when it searches the whole frame. ft-eyes keeps OpenCV and numpy to one thread: their pools of one per core spun idle workers at about a quarter of a core, for frames this small. It also runs at nice 10 with SCHED_BATCH, and ft-gaze at nice 5 (not batch, since each sample goes on to the pointer): both run in the dev container's podman scope, out of reach of the gaze service's unit, on the cores vrcompositor and vrserver use at nice 0. Replays, scoring, and training go to a PC.
 
 ## Headset fit
 

gaze/ft-gaze.cpp

@@ -4,7 +4,14 @@
 // Every eye tracker sample (90 Hz) becomes one JSON line on stdout with each gaze source
 // hit-tested against the Frametop screens:
 //
-// Options: -v (log action errors), --watch-stdin (quit when stdin closes).
+// Options: -v (log action errors), --watch-stdin (quit when stdin closes; until then, a line
+// "sources LIST" on stdin switches the sources as --sources does), --sources LIST (comma-
+// separated: action, mmap1, mmap2, left, right, own, and eye for EYE; or all, the default).
+// Sources left out are read not at all and print as {"ok":0} ("eye" as null), so every line
+// keeps the same keys. The gaze service asks for the ones it uses (own and mmap1 with our
+// tracker), and all of them while a check or the calibration runs. Only the action costs
+// SteamVR anything (two calls into vrserver per sample), and a line with every source is
+// about 1.5 KB, 130 KB a second through podman's relay.
 //
 //   {"t":<sample time, CLOCK_MONOTONIC_RAW s>,"age":<ms old when read>,"n":<sample counter>,
 //    "head":{"yaw":..,"pitch":..,"hit":HIT},          head forward ray (for head nudging)
@@ -58,6 +65,7 @@
 
 #include <algorithm>
 #include <atomic>
+#include <cerrno>
 #include <chrono>
 #include <climits>
 #include <cmath>
@@ -72,6 +80,7 @@
 
 #include <fcntl.h>
 #include <sys/mman.h>
+#include <sys/resource.h>
 #include <sys/socket.h>
 #include <sys/stat.h>
 #include <sys/un.h>
@@ -389,6 +398,30 @@ std::string SrcJson(const std::vector<Screen> &screens, const vr::HmdMatrix34_t
     return buf + extra + "\"hit\":" + HitJson(screens, head, yaw, pitch) + "}";
 }
 
+// Sources (--sources, "sources LIST" on stdin): a bit each.
+enum : unsigned { kAction = 1, kMmap1 = 2, kMmap2 = 4, kLeft = 8, kRight = 16, kOwn = 32, kEye = 64, kAll = 127 };
+
+bool ParseSources(const std::string &list, unsigned &mask) {
+    static const struct {
+        const char *name;
+        unsigned bit;
+    } names[] = {{"action", kAction}, {"mmap1", kMmap1}, {"mmap2", kMmap2}, {"left", kLeft},
+                 {"right", kRight},   {"own", kOwn},     {"eye", kEye},     {"all", kAll}};
+    unsigned m = 0;
+    size_t at = 0;
+    while (at <= list.size()) {
+        const size_t comma = std::min(list.find(',', at), list.size());
+        const std::string name = list.substr(at, comma - at);
+        bool known = false;
+        for (const auto &n : names)
+            if (name == n.name) m |= n.bit, known = true;
+        if (!known) return false;
+        at = comma + 1;
+    }
+    mask = m;
+    return true;
+}
+
 // Head poses of the last half second, so a sample can use the pose at its own time.
 class PoseHistory {
 public:
@@ -426,17 +459,42 @@ std::string ExeDir() {
 
 int main(int argc, char **argv) {
     bool verbose = false, watchStdin = false;
+    std::atomic<unsigned> sources{kAll};
     for (int i = 1; i < argc; ++i) {
         if (std::strcmp(argv[i], "-v") == 0) verbose = true;
         if (std::strcmp(argv[i], "--watch-stdin") == 0) watchStdin = true;
+        if (std::strcmp(argv[i], "--sources") == 0 && i + 1 < argc) {
+            unsigned m;
+            if (ParseSources(argv[++i], m))
+                sources = m;
+            else
+                std::fprintf(stderr, "ft-gaze: --sources %s: unknown source (all used)\n", argv[i]);
+        }
     }
+    // Nice 5, before any thread starts (they inherit it): we run in the dev container's podman
+    // scope, beside vrcompositor and vrserver at nice 0, and the gaze service's unit doesn't
+    // reach us. Not SCHED_BATCH, as ft-eyes is: that would let each wakeup wait out another
+    // task's turn, and each sample goes on to the pointer.
+    errno = 0;
+    const int nice0 = getpriority(PRIO_PROCESS, 0);
+    if (errno == 0 && nice0 < 5 && setpriority(PRIO_PROCESS, 0, 5) != 0)
+        std::fprintf(stderr, "ft-gaze: nice: %s\n", std::strerror(errno));
     // --watch-stdin: quit when stdin closes. The probe runs us through distrobox, which
     // passes neither its signals nor a closed stdout on to us, but does pass stdin's end.
+    // Lines on stdin until then: "sources LIST".
     std::atomic<bool> stdinClosed{false};
     if (watchStdin)
-        std::thread([&stdinClosed] {
+        std::thread([&stdinClosed, &sources] {
             char c[256];
-            while (read(0, c, sizeof c) > 0) {
+            std::string line;
+            ssize_t n;
+            while ((n = read(0, c, sizeof c)) > 0) {
+                line.append(c, size_t(n));
+                for (size_t nl; (nl = line.find('\n')) != std::string::npos; line.erase(0, nl + 1)) {
+                    unsigned m;
+                    if (line.compare(0, 8, "sources ") == 0 && ParseSources(line.substr(8, nl - 8), m)) sources = m;
+                }
+                if (line.size() > 4096) line.clear();  // no newline in sight: not ours
             }
             stdinClosed = true;
         }).detach();
@@ -509,6 +567,7 @@ int main(int argc, char **argv) {
 
         if (fresh && hp.bPoseIsValid) {
             lastEmit = now;
+            const unsigned want = sources;
             const auto list = screens.Get();
             const vr::HmdMatrix34_t &headNow = hp.mDeviceToAbsoluteTracking;
             vr::HmdMatrix34_t headThen = headNow;
@@ -517,7 +576,7 @@ int main(int argc, char **argv) {
             // SteamVR's action: a room-space origin and fixation point, turned into the head
             // frame so every source reports the same kind of angles.
             std::string action = "{\"ok\":0}";
-            if (!inGame) {
+            if (!inGame && (want & kAction)) {
                 vr::VRActiveActionSet_t active{};
                 active.ulActionSet = set;
                 active.nPriority = vr::k_nActionSetOverlayGlobalPriorityMin;
@@ -560,26 +619,33 @@ int main(int argc, char **argv) {
                     return std::string(b);
                 };
                 char extra[256];
-                std::snprintf(extra, sizeof extra, "\"dist\":%.3f,\"open\":[%.3f,%.3f],\"lr\":%.3f,", Length(s.fix1),
+                if (want & kMmap1) {
-                              s.open[0], s.open[1], lr(s.left1, s.right1));
+                    std::snprintf(extra, sizeof extra, "\"dist\":%.3f,\"open\":[%.3f,%.3f],\"lr\":%.3f,", Length(s.fix1),
-                m1 = SrcJson(list, headThen, s.left1 + s.right1, extra + eyes(s.left1, s.right1) + unc(s.var1));
+                                  s.open[0], s.open[1], lr(s.left1, s.right1));
-                std::snprintf(extra, sizeof extra, "\"lr\":%.3f,", lr(s.left2, s.right2));
+                    m1 = SrcJson(list, headThen, s.left1 + s.right1, extra + eyes(s.left1, s.right1) + unc(s.var1));
-                m2 = SrcJson(list, headThen, s.left2 + s.right2, extra + eyes(s.left2, s.right2) + unc(s.var2));
+                }
-                left = SrcJson(list, headThen, s.left2);
+                if (want & kMmap2) {
-                right = SrcJson(list, headThen, s.right2);
+                    std::snprintf(extra, sizeof extra, "\"lr\":%.3f,", lr(s.left2, s.right2));
+                    m2 = SrcJson(list, headThen, s.left2 + s.right2, extra + eyes(s.left2, s.right2) + unc(s.var2));
+                }
+                if (want & kLeft) left = SrcJson(list, headThen, s.left2);
+                if (want & kRight) right = SrcJson(list, headThen, s.right2);
+                // "new" compares with the last sample, so the last measurement is kept either way.
                 const float *m = s.meas;
                 const bool newL = m[0] != lastMeas[0] || m[1] != lastMeas[1];
                 const bool newR = m[2] != lastMeas[2] || m[3] != lastMeas[3];
                 std::memcpy(lastMeas, m, sizeof lastMeas);
-                std::snprintf(extra, sizeof extra, "{\"q\":[%.3g,%.3g],\"m\":[[%.4f,%.4f],[%.4f,%.4f]],\"new\":[%d,%d]}",
+                if (want & kEye) {
-                              (m[4] + m[5]) / 2, (m[6] + m[7]) / 2, m[0], m[1], m[2], m[3], int(newL), int(newR));
+                    std::snprintf(extra, sizeof extra, "{\"q\":[%.3g,%.3g],\"m\":[[%.4f,%.4f],[%.4f,%.4f]],\"new\":[%d,%d]}",
-                eye = extra;
+                                  (m[4] + m[5]) / 2, (m[6] + m[7]) / 2, m[0], m[1], m[2], m[3], int(newL), int(newR));
+                    eye = extra;
+                }
             }
 
             // Our tracker: its own sample time picks the head pose, like the mmap's.
             std::string own = "{\"ok\":0}";
             OwnSample o;
-            if (ownFile.Read(o) && now - o.t < 0.1) {
+            if ((want & kOwn) && ownFile.Read(o) && now - o.t < 0.1) {
                 vr::HmdMatrix34_t headOwn = headNow;
                 history.At(o.t, headOwn);
                 auto pair = [](bool ok, float a, float b) {
@@ -624,7 +690,10 @@ int main(int argc, char **argv) {
             break;
         }
         if (stdinClosed) break;
-        std::this_thread::sleep_for(std::chrono::milliseconds(2));
+        // 250 passes a second: a new sample is printed within 4 ms (2 on average) of appearing,
+        // and the pose history has a pose within 2 ms of any sample's time (a 0.2 degree head
+        // turn at 100 degrees a second). Every 2 ms read the pose and the events twice as often.
+        std::this_thread::sleep_for(std::chrono::milliseconds(4));
     }
     screens.Stop();
     vr::VR_Shutdown();

gaze/ft-gazed

@@ -63,9 +63,24 @@ and the error moves): lessons from before count less then, so the first few afte
 relearn the offset.
 
 Our own tracker (gaze/tracker/ft-eyes) runs here too, in the dev container, while
-GAZE_TRACKER=own or the gaze probe asks for it ("eyes SECONDS", a lease the probe renews). It
+GAZE_TRACKER=own and the gaze is in use (below), or the gaze probe asks for it ("eyes SECONDS",
-reads the eye-camera frames the root service frametop-eyegrab copies (gaze/tracker/install.sh),
+a lease the probe renews). It reads the eye-camera frames the root service frametop-eyegrab
-which copies them only while ft-eyes runs.
+copies (gaze/tracker/install.sh), which copies them only while ft-eyes runs.
+
+Idle: ft-gaze and our own tracker run only while the gaze is in use: gaze mode on with someone
+wearing the headset (the pointer helper says both: "gaze ? headset" -> "ok on|off worn|away"), a
+check or calibration open or asked for, or a "wake" lease (the Gaze page of Frametop Input
+Settings renews one while it's open). IDLE_AFTER after the last use they stop, and the frame
+grabber goes idle with our tracker; with our tracker, that was over half a core with gaze mode
+off. A check asked for while idle waits for the tracker to start (at most WAKE_SETTLE). Our
+tracker's next click after it starts again re-seats it, as after the headset was off, so turning
+gaze mode on after a while opens the quick check.
+
+ft-gaze prints only the sources this uses ("sources LIST" on its stdin, see wanted_sources):
+own and mmap1 with our tracker, left, right and mmap1 with SteamVR's eyes, and every source
+while a check or the calibration runs or is asked for, since those record them all. So
+SteamVR's gaze action, the one source that calls into vrserver, is read only then (or with
+--source action).
 
 Checks and calibration (gaze/gazecheck.py): a one-dot quick check when the headset goes on or
 our tracker asks for a click, and the full calibration when gaze mode comes on without one,
@@ -83,6 +98,8 @@ Control socket: abstract unix datagram "@ft_gazed":
   reload                           read calibration.json and the settings again
   eyes <seconds>                   keep our own tracker running that much longer (at most 120),
                                    whatever GAZE_TRACKER says: the probe's lease. Reply: "ok"
+  wake <seconds>                   keep the gaze running (not idle) that much longer (at most 120),
+                                   whatever gaze mode says: Input Settings' Gaze page. Reply: "ok"
   quickcal                         the one-dot check now (the calibration if there's none)
   calibrate                        the full calibration in the panel
   fitcheck                         the headset fit check in the panel
@@ -140,6 +157,9 @@ RETRY = 3.0       # seconds before starting ft-gaze again
 EYES_RETRY = 10.0  # seconds before starting ft-eyes again after it stopped on its own
 EYES_LEASE_MAX = 120.0
 SETTLE = 0.3      # seconds after an eye is found again before the fallback learns from it
+IDLE_AFTER = 30.0  # seconds after the gaze was last in use before ft-gaze and our tracker stop
+WAKE_SETTLE = 15.0  # seconds after waking that the tracker may take to start sending
+WAKE_MAX = 120.0
 KEYBOARD_PITCH = -20.0  # degrees: gaze under this, on no screen, is a look at the keyboard
 
 
@@ -230,6 +250,10 @@ class Service:
         self.eyes_proc = None  # ft-eyes, while it runs
         self.eyes_until = 0.0  # the probe's lease (monotonic time)
         self.eyes_restart_at = 0.0
+        self.awake = False      # ft-gaze (and our tracker) run: the gaze is in use (see the top)
+        self.idle_at = 0.0      # idle from then, unless it's in use again first
+        self.woke_at = 0.0
+        self.wake_until = 0.0   # a "wake" lease
 
         self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM | socket.SOCK_CLOEXEC | socket.SOCK_NONBLOCK)
         self.sock.bind(ME)
@@ -242,6 +266,7 @@ class Service:
         self.sel.register(self.eyes_sock, selectors.EVENT_READ, "own")
         self.checks = Checks(self, self.sel)
         self.proc = None
+        self.proc_sources = None  # what ft-gaze was last told to print
         self.buf = b""
         self.restart_at = 0.0
         self.running = True
@@ -399,8 +424,73 @@ class Service:
             log(f"lesson log: {e}")
         return rec
 
+    # --- Idle (see the top) ---
+
+    def use_reason(self):
+        """Why the gaze is in use now, or None."""
+        c = self.checks
+        if c.gaze_on and c.headset is not False:
+            return "gaze mode is on"
+        if c.active or c.pending:
+            return "a check"
+        if time.monotonic() < self.wake_until:
+            return "asked to stay awake"
+        return None
+
+    def idle_reason(self):
+        c = self.checks
+        if c.gaze_on is None:
+            return "the pointer helper isn't answering (SteamVR not running?)"
+        if c.gaze_on and c.headset is False:
+            return "nobody is wearing the headset"
+        return "gaze mode is off"
+
+    def waking(self):
+        """Idle, or awake too briefly for the tracker to be sending yet."""
+        return not self.awake or time.monotonic() - self.woke_at < WAKE_SETTLE
+
+    def update_awake(self):
+        now = time.monotonic()
+        why = self.use_reason()
+        if why:
+            self.idle_at = now + IDLE_AFTER
+        if why and not self.awake:
+            self.awake, self.woke_at, self.restart_at = True, now, 0.0
+            log(f"awake: {why}")
+        elif not why and self.awake and now >= self.idle_at:
+            self.awake = False
+            log(f"idle: {self.idle_reason()}; ft-gaze and our tracker stop until the gaze is used again")
+            self.stop_helper()
+            if self.eyes_proc and not self.eyes_wanted():
+                self.stop_eyes()
+
     # --- ft-gaze ---
 
+    def wanted_sources(self):
+        """The sources ft-gaze should print (its --sources): what on_sample and the checks read.
+        mmap1 always (blinks, lost eyes, and the headset going on, from its openness and
+        variances); everything while a check runs or waits, since they record every source."""
+        c = self.checks
+        if c.active or c.pending:
+            return "all"
+        kind = self.kind
+        if kind == "own":
+            return "own,mmap1"
+        if kind == "eyes":
+            return "left,right,mmap1"
+        return ",".join(dict.fromkeys((self.source, "mmap1", "mmap2")))  # mmap2: each eye, for the fallback
+
+    def sync_sources(self):
+        want = self.wanted_sources()
+        if not self.proc or want == self.proc_sources:
+            return
+        try:
+            self.proc.stdin.write(f"sources {want}\n".encode())
+            self.proc.stdin.flush()
+        except (OSError, ValueError):
+            return  # it's stopping: read_stdout notices
+        self.proc_sources = want
+
     def start_helper(self):
         if not HELPER.exists():
             log(f"ft-gaze isn't built: run {REPO}/gaze/build.sh")
@@ -411,9 +501,11 @@ class Service:
         subprocess.run([str(REPO / "scripts" / "container-up.sh")], env=env, check=False)
         distrobox = Path.home() / ".local" / "bin" / "distrobox"
         # ft-gaze quits when its stdin closes: the one thing distrobox passes on.
-        self.proc = subprocess.Popen([str(distrobox), "enter", "dev", "--", str(HELPER), "--watch-stdin"], env=env,
+        sources = self.wanted_sources()
-                                     stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+        self.proc = subprocess.Popen([str(distrobox), "enter", "dev", "--", str(HELPER), "--watch-stdin",
-                                     start_new_session=True)
+                                      "--sources", sources], env=env, stdin=subprocess.PIPE, stdout=subprocess.PIPE,
+                                     stderr=subprocess.PIPE, start_new_session=True)
+        self.proc_sources = sources
         os.set_blocking(self.proc.stdout.fileno(), False)
         os.set_blocking(self.proc.stderr.fileno(), False)
         self.sel.register(self.proc.stdout, selectors.EVENT_READ, "stdout")
@@ -441,7 +533,7 @@ class Service:
         self.proc = None
 
     def eyes_wanted(self):
-        return (self.tracker == "own" and not self.override) or time.monotonic() < self.eyes_until
+        return (self.tracker == "own" and not self.override and self.awake) or time.monotonic() < self.eyes_until
 
     def start_eyes(self):
         """Our own tracker, in the dev container, with build/venv's numpy and OpenCV. Like
@@ -700,6 +792,14 @@ class Service:
                     reply = "ok"
                 except ValueError:
                     reply = "error bad seconds"
+            elif words[:1] == ["wake"] and len(words) == 2:
+                try:
+                    secs = min(max(float(words[1]), 0.0), WAKE_MAX)
+                    self.wake_until = max(self.wake_until, time.monotonic() + secs)
+                    self.update_awake()
+                    reply = "ok"
+                except ValueError:
+                    reply = "error bad seconds"
             elif words[:1] == ["reload"]:
                 self.load_settings()
                 self.load_calibration()
@@ -750,6 +850,7 @@ class Service:
             st.update(calibration_samples=cal.get("dots", 0), calibration_made=cal.get("made"),
                       lessons=max(len(m) for m in w.misses), own_running=bool(own),
                       own_reseat=any(e.get("reseat") for e in own.get("eyes", {}).values()))
+        st.update(awake=self.awake, idle=None if self.awake else self.idle_reason())
         st.update(eyes_process=self.eyes_proc is not None, eyegrab=EYES_CAMS.exists(),
                   tracker_setting=self.tracker_setting, own_installed=own_installed())
         st.update({"ft_gaze": self.proc is not None, "sample_age_s": round(time.monotonic() - self.last_sample, 2)
@@ -770,6 +871,7 @@ class Service:
         if mtime(CONF) != self.conf_mtime or (self.tracker_setting == "auto"
                                               and own_installed() != (self.tracker == "own")):
             self.load_settings()
+        self.update_awake()
         want = self.eyes_wanted()
         if want and not self.eyes_proc and time.monotonic() >= self.eyes_restart_at:
             self.start_eyes()
@@ -790,7 +892,7 @@ class Service:
         next_verbose = time.monotonic() + 5
         while self.running:
             now = time.monotonic()
-            if not self.proc and now >= self.restart_at:
+            if self.awake and not self.proc and now >= self.restart_at:
                 self.start_helper()
             for key, _ in self.sel.select(timeout=0.05 if self.checks.active else 0.5):
                 if key.data == "control":
@@ -808,6 +910,7 @@ class Service:
                 elif key.data == "stderr" and self.proc:
                     self.read_stderr()
             self.checks.tick()
+            self.sync_sources()
             if now >= next_periodic:
                 self.periodic()
                 next_periodic = now + 1.0

gaze/gazecheck.py

@@ -10,7 +10,9 @@ directions: look at each one.
           once every QUICK_COOLDOWN, and on "quickcal" (Frametop Input Settings, or a mouse
           button or key combination mapped to Gaze quick check), and when a click's correction
           was past POINTER_GAZE_NUDGE_MAX (55 degrees; the helper's "recheck"): the tracker is
-          far off. Ignored, it closes after QUICK_TIMEOUT and changes nothing.
+          far off. Ignored, it closes after QUICK_TIMEOUT and changes nothing. The headset going
+          on is seen only while the gaze service is awake (gaze mode on, someone wearing it: see
+          ft-gazed), so it also opens when gaze mode comes on after the service idled.
   five    the middle and four around it, when the first FIVE_COUNT lessons after a quick check
           were all over FIVE_LIMIT degrees off: the quick check didn't fix it.
   full    the calibration, as the gaze probe's: three rounds, dark, medium and bright (pupil
@@ -30,6 +32,9 @@ directions: look at each one.
           adjust the headset. A left click or Meta+J runs its guided check (dots, then looks
           down, up, left and right); a right click or Meta+K closes it, as does FIT_TIMEOUT.
 
+A check asked for while the gaze service idles (quickcal, calibrate, fitcheck) wakes it and
+waits until the tracker sends, at most ft-gazed's WAKE_SETTLE; then it opens, or logs why not.
+
 The quick check's dot captures itself: from CHECK_SETTLE after it shows (the eyes getting
 there), once the gaze has held within CHECK_SPREAD for CHECK_WINDOW (the probe's max spread and
 capture time). It's the gaze holding still that counts, not where the tracker puts it, so it
@@ -209,7 +214,9 @@ class Checks:
         sel.register(self.out, selectors.EVENT_READ, "checks")
         self.check = None
         self.gaze_on = None
+        self.headset = None      # someone wears it (the helper's "worn"), False "away", None unknown
         self.gaze_heard = 0.0
+        self.pending = None      # (command words, when): asked for while the gaze service idled
         self.full_armed = True    # gaze mode on without a calibration opens the full one (need_full)
         self.full_blocked = None  # why it can't open now
         self.full_retry_at = 0.0
@@ -294,17 +301,22 @@ class Checks:
             pass
 
     def on_readable(self):
-        """Replies on our socket: the helper's "ok on|off" to "gaze ?"; the panel's are dropped."""
+        """Replies on our socket: the helper's "ok on|off [worn|away]" to "gaze ? headset" (an
+        older helper leaves the headset out); the panel's are dropped."""
         while True:
             try:
-                data = self.out.recv(4096).decode("utf-8", "replace")
+                words = self.out.recv(4096).decode("utf-8", "replace").split()
             except (BlockingIOError, OSError):
                 return
-            if data in ("ok on", "ok off"):
+            if words[:1] == ["ok"] and len(words) in (2, 3) and words[1] in ("on", "off"):
-                on = data == "ok on"
+                on = words[1] == "on"
-                was, self.gaze_on, self.gaze_heard = self.gaze_on, on, time.monotonic()
+                headset = None if len(words) == 2 else words[2] == "worn"
-                if on and was is False:
+                was = (self.gaze_on, self.headset)
+                self.gaze_on, self.headset, self.gaze_heard = on, headset, time.monotonic()
+                if on and was[0] is False:
                     self.on_gaze_on()
+                if was != (on, headset):
+                    self.svc.update_awake()
 
     # --- State ---
 
@@ -341,6 +353,8 @@ class Checks:
             self.full_blocked = None
             return
         now = time.monotonic()
+        if not self.can_run() and self.svc.waking():
+            return  # the tracker is still starting (the service idled)
         if not self.can_run():
             why = ("the eye tracker isn't sending" if now - self.svc.last_sample >= 2
                    else "no eyes seen (is the headset on?)")
@@ -490,6 +504,8 @@ class Checks:
 
     def on_sample(self, s):
         self.sample_at = time.monotonic()
+        if self.pending:
+            self.run_pending()
         unc = (s["src"].get("mmap1") or {}).get("unc")
         if unc and min(unc) <= EYE_LOST:
             self.seen_at = time.monotonic()
@@ -742,9 +758,28 @@ class Checks:
 
     # --- From the service ---
 
-    def command(self, words):
+    def run_pending(self):
+        """A check asked for while the service idled: once the tracker sends (and our tracker has
+        said whether it's calibrated), or WAKE_SETTLE after waking, when its error is the real one."""
+        svc = self.svc
+        words, _ = self.pending
+        ready = (time.monotonic() - svc.last_sample < 2 if words[0] == "fitcheck" else self.can_run()) \
+            and (svc.kind != "own" or self.calibrated() is not None)
+        if not ready and svc.waking():
+            return
+        self.pending = None
+        reply = self.command(words, queue=False)
+        if reply != "ok":
+            log(f"{words[0]}, asked for while idle: {reply.removeprefix('error ')}")
+
+    def command(self, words, queue=True):
         """quickcal, calibrate, calaccept, calquit -> a reply."""
         cmd = words[0]
+        if cmd in ("quickcal", "calibrate", "fitcheck") and queue and self.svc.waking() and not self.check:
+            # The tracker isn't running (or only just started): wake it, and do this once it sends.
+            self.pending = (words, time.monotonic())
+            self.svc.update_awake()
+            return "ok waking the eye tracker first"
         if cmd == "quickcal":
             return self.start("full" if self.calibrated() is False else "quick", "asked for")
         if cmd == "calibrate":
@@ -820,9 +855,11 @@ class Checks:
         now = time.monotonic()
         if not self.panel_proc and now >= self.panel_restart_at:
             self.start_panel()
-        self.to_helper("gaze ?")
+        self.to_helper("gaze ? headset")
         if now - self.gaze_heard > 5:
-            self.gaze_on = None  # the helper isn't answering
+            self.gaze_on = self.headset = None  # the helper isn't answering
+        if self.pending:
+            self.run_pending()
         if self.check:
             self.to_helper("calpanel 1")
         if not self.eyes_seen(AWAY_MIN):
@@ -844,7 +881,8 @@ class Checks:
 
     def status(self):
         c = self.check
-        st = {"check": None, "gaze_mode": self.gaze_on, "calibrated": self.calibrated(), "eyes": self.eyes_seen(),
+        st = {"check": None, "gaze_mode": self.gaze_on, "headset_worn": self.headset, "pending": self.pending[0][0]
+              if self.pending else None, "calibrated": self.calibrated(), "eyes": self.eyes_seen(),
               "problem": self.problem(),
               "panel": self.panel_proc is not None,
               "last_quick_s": round(time.monotonic() - self.last_quick) if self.last_quick else None}

gaze/panel/ft-gazepanel.cpp

@@ -47,6 +47,7 @@
 #include <drm_fourcc.h>
 #include <fcntl.h>
 #include <gbm.h>
+#include <poll.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <unistd.h>
@@ -524,7 +525,11 @@ int main(int argc, char **argv) {
             if (!shown) ov->ShowOverlay(h), shown = true;
             dirty = false;
         }
-        std::this_thread::sleep_for(std::chrono::milliseconds(visible ? 10 : 50));
+        // Until a command comes, or 10 ms while shown (SteamVR's events). Hidden, it waits up to a
+        // second: it woke 20 to 30 times a second for nothing, the main cost left with gaze idle.
+        // A closed stdin (--watch-stdin) wakes it too, so quitting doesn't wait.
+        pollfd fds[2] = {{sock, POLLIN, 0}, {0, POLLIN, 0}};
+        poll(fds, watchStdin ? 2 : 1, visible ? 10 : 1000);
     }
     ov->DestroyOverlay(h);
     buffers.Drop();

gaze/test/idle-test.py

@@ -0,0 +1,178 @@
+#!/usr/bin/env python3
+"""Offline test of the gaze service idling (gaze/ft-gazed, gaze/gazecheck.py): ft-gaze runs only
+while the gaze is in use, and a check asked for while it idles waits for the tracker.
+
+Runs ft-gazed's Service with its sockets renamed, a fake pointer helper (answers "gaze ?
+headset" as the test says), and a fake ft-gaze (prints samples, quits when its stdin closes).
+SteamVR's tracker is the one in use, so our own isn't started; the panel isn't either. Nothing
+reaches the live gaze service, the pointer helper, or SteamVR, so it's safe next to them.
+
+  gaze/test/idle-test.py
+"""
+import importlib.machinery
+import importlib.util
+import os
+import socket
+import subprocess
+import sys
+import tempfile
+import threading
+import time
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+GAZE = os.path.join(HERE, "..")
+sys.path.insert(0, GAZE)
+loader = importlib.machinery.SourceFileLoader("ftgazed", os.path.join(GAZE, "ft-gazed"))
+gazed = importlib.util.module_from_spec(importlib.util.spec_from_loader("ftgazed", loader))
+loader.exec_module(gazed)
+import gazecheck  # noqa: E402  (the module ft-gazed imported)
+
+tag = f"ft_gaze_idle_test_{os.getpid()}"
+gazed.ME = f"\0{tag}_gazed"
+gazed.POINTER = gazecheck.POINTER = f"\0{tag}_helper"
+gazecheck.SCREENS = f"\0{tag}_screens"
+gazecheck.PANEL_PROG = gazed.REPO / "nonexistent-panel"  # "isn't built": no panel
+gazed.IDLE_AFTER, gazed.WAKE_SETTLE = 1.0, 3.0
+gazed.read_settings = lambda: ("steam", "steam", "auto", 55.0)
+logs = []
+gazed.log = gazecheck.log = lambda msg: logs.append(msg)
+
+# The fake ft-gaze: 90 samples a second, both eyes seen, until its stdin closes. It logs the
+# sources it was asked for: "argv LIST" (--sources), then "line LIST" for each "sources LIST".
+tmp = tempfile.mkdtemp(prefix="ft-gaze-idle-test-")
+FAKE = os.path.join(tmp, "ft-gaze")
+SOURCES_LOG = os.path.join(tmp, "sources.log")
+with open(FAKE, "w") as f:
+    f.write('''import json, os, select, sys, time
+log = open(sys.argv[1], "a", buffering=1)
+log.write("argv " + (sys.argv[sys.argv.index("--sources") + 1] if "--sources" in sys.argv else "-") + "\\n")
+buf = b""
+while True:
+    if select.select([sys.stdin], [], [], 1 / 90)[0]:
+        data = os.read(0, 4096)
+        if not data:
+            break
+        buf += data
+        while b"\\n" in buf:
+            line, buf = buf.split(b"\\n", 1)
+            if line.startswith(b"sources "):
+                log.write("line " + line[8:].decode() + "\\n")
+    eye = {"hy": 1.0, "hp": 2.0}
+    print(json.dumps({"t": time.monotonic(), "src": {"mmap1": {"hy": 1.0, "hp": 2.0, "unc": [0.001, 0.001],
+          "open": [0.8, 0.8]}, "left": eye, "right": eye}}), flush=True)
+''')
+started = []
+
+
+def start_helper(self):
+    """ft-gaze, straight from here instead of the dev container."""
+    import selectors
+    self.proc = subprocess.Popen([sys.executable, FAKE, SOURCES_LOG, "--sources", self.wanted_sources()],
+                                 stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+    self.proc_sources = self.wanted_sources()
+    os.set_blocking(self.proc.stdout.fileno(), False)
+    os.set_blocking(self.proc.stderr.fileno(), False)
+    self.sel.register(self.proc.stdout, selectors.EVENT_READ, "stdout")
+    self.sel.register(self.proc.stderr, selectors.EVENT_READ, "stderr")
+    self.buf = b""
+    started.append(time.monotonic())
+
+
+gazed.Service.start_helper = start_helper
+
+# The fake pointer helper.
+helper_state = {"reply": "ok off worn"}
+helper = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+helper.bind(gazed.POINTER)
+helper.settimeout(0.2)
+
+
+def answer():
+    while True:
+        try:
+            data, addr = helper.recvfrom(512)
+        except socket.timeout:
+            continue
+        except OSError:
+            return
+        if data.startswith(b"gaze ?") and addr:
+            helper.sendto(helper_state["reply"].encode(), addr)
+
+
+threading.Thread(target=answer, daemon=True).start()
+svc = gazed.Service(None, False, gazed.POINTER)
+threading.Thread(target=svc.run, daemon=True).start()
+ctl = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+ctl.bind("")
+ctl.settimeout(2)
+
+
+def ask(cmd):
+    ctl.sendto(cmd.encode(), gazed.ME)
+    return ctl.recv(4096).decode()
+
+
+failures = []
+
+
+def check(label, got, want):
+    ok = got == want
+    print(("ok    " if ok else "FAIL  ") + label + ("" if ok else f": got {got!r}, want {want!r}"), flush=True)
+    if not ok:
+        failures.append(label)
+
+
+def wait(cond, seconds):
+    end = time.monotonic() + seconds
+    while time.monotonic() < end:
+        if cond():
+            return True
+        time.sleep(0.05)
+    return cond()
+
+
+time.sleep(2.5)
+check("gaze mode off: idle, no ft-gaze", (svc.awake, svc.proc is None), (False, True))
+check("status says why", ask("status").count('"idle": "gaze mode is off"'), 1)
+
+helper_state["reply"] = "ok on worn"
+check("gaze mode on, headset worn: awake within 2 s", wait(lambda: svc.awake and svc.proc is not None, 2.5), True)
+check("samples come in", wait(lambda: svc.counts["samples"] > 20, 2), True)
+
+helper_state["reply"] = "ok on away"
+check("headset off: still awake for IDLE_AFTER", wait(lambda: not svc.awake, 0.5), False)
+check("then idle, ft-gaze stopped", wait(lambda: not svc.awake and svc.proc is None, 3.5), True)
+check("why: nobody wears it", ask("status").count('"idle": "nobody is wearing the headset"'), 1)
+
+helper_state["reply"] = "ok on"
+check("an older helper (no headset word): awake with gaze mode on", wait(lambda: svc.awake, 2.5), True)
+helper_state["reply"] = "ok off worn"
+check("gaze mode off again: idle", wait(lambda: not svc.awake and svc.proc is None, 4.5), True)
+
+check("wake lease", ask("wake 2"), "ok")
+check("wake: awake at once", (svc.awake, wait(lambda: svc.proc is not None, 1)), (True, True))
+check("lease over (2 s + IDLE_AFTER): idle", wait(lambda: not svc.awake, 4.5), True)
+
+time.sleep(0.5)
+logs.clear()
+open(SOURCES_LOG, "w").close()
+count = len(started)
+check("quick check while idle: queued, waking", ask("quickcal"), "ok waking the eye tracker first")
+check("it woke", wait(lambda: svc.awake and len(started) > count, 1.5), True)
+check("once the tracker sends, it ran (and says why it couldn't open)",
+      wait(lambda: any("quickcal, asked for while idle: the panel isn't running" in m for m in logs), 3), True)
+check("nothing left pending", svc.checks.pending, None)
+sources = open(SOURCES_LOG).read().split("\n")
+check("ft-gaze started with every source for the check", sources[0], "argv all")
+in_use = svc.wanted_sources()
+check("then only those in use (SteamVR's tracker: not the action, not own)",
+      (f"line {in_use}" in sources, in_use != "all", "action" in in_use, "own" in in_use), (True, True, False, False))
+check("idle again after", wait(lambda: not svc.awake, 3), True)
+
+print("FAILED: " + ", ".join(failures) if failures else "all passed", flush=True)
+svc.running = False
+time.sleep(0.7)
+os.remove(FAKE)
+os.remove(SOURCES_LOG)
+os.rmdir(tmp)
+os._exit(1 if failures else 0)

gaze/tracker/eyes_pupil.py

@@ -9,7 +9,12 @@ the search runs again with a smaller closing.
 import cv2
 import numpy as np
 
-DARK = 30          # pupil pixels are below this (the face around it is 40-180)
+# One thread: OpenCV's pool of one per core costs more than it saves on a frame this small
+# (a 140-240 px window while it follows the pupil). Its idle workers spun and yielded about
+# 14,000 times a second each, a quarter of a core, beside SteamVR's compositor.
+cv2.setNumThreads(1)
+
+DARK = 30         # pupil pixels are below this (the face around it is 40-180)
 MIN_AREA = 150     # pupil area range in pixels
 MAX_AREA = 20000
 MIN_FILL = 0.75    # blob area / fitted-ellipse area

gaze/tracker/findings.md

@@ -63,6 +63,13 @@ reading only.
     frame when its camera starts the frame after next (no slot is rewritten sooner than three
     frames), ignores late writes to the frame just finished, and saves from a separate
     thread. fit1 may hold a few percent of torn frames.
+  - `--share` (2026-10-03) checks only the slot each camera writes next, from the two before
+    (the orders above, learned again if they change; all four slots for 2 s after a frame turns
+    up elsewhere), sleeps until 2.5 ms before the next frame is due, then looks every 1 ms with
+    0.5 ms of timer slack. Against the 0.3 ms poll of all eight slots, on simulated cameras:
+    207 wakeups a second instead of 1,486, 0.8% of a core instead of 3.6% (more on the real
+    DMA-BUF memory), no torn or skipped frames, and a frame's start seen 1.35 ms late on
+    average instead of 0.76. `--rec` still polls all slots every 0.3 ms, for its times.
   - Eye tracking stops when the headset is off ("HMD off, stopping eye tracking"), so
     recordings are empty then.
 - **Which camera is which eye** (capture fit1, 2026-09-29, closing one eye at a time):

gaze/tracker/ft-eyegrab.c

@@ -46,6 +46,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include <sys/mman.h>
+#include <sys/prctl.h>
 #include <sys/stat.h>
 #include <sys/syscall.h>
 #include <time.h>
@@ -288,20 +289,53 @@ static int eye_buffer(void) {
 
 // Calls done(frame, slot, time) for every complete eye-camera frame until `seconds` pass
 // (forever if negative), a stop signal comes, the tracker process goes away, or keep()
-// (checked about every 0.25 s, when given) says to stop.
+// (checked about every 0.25 s, when given) says to stop. Looks every `poll_us`.
 //
 // A frame lands over several milliseconds, in bursts, and its last bursts can come after
 // the camera has started its next frame. A slot isn't rewritten until at least three frames
 // later (camera 0 cycles 3,0,1,2; camera 1 7,5,4,6,5,7,6,4), so a frame is passed on when
 // its camera starts the frame after next. Changes to the slot just finished are late bursts,
 // not a new frame. A frame's time is when its slot first changed.
+//
+// Each look checks only the slot each camera writes next: the one that followed the last two
+// before (after[][], seeded with the orders above and learned as frames come). Every check
+// reads 256 words spread over a frame in DMA-BUF memory, so all eight slots each time was
+// most of the cost. A camera with nothing in its expected slot for 1.5 frames, or with no
+// order known yet, has all its slots checked until a frame comes. When that finds a frame
+// somewhere else (the order changed, or a frame was missed), all its slots are checked for
+// SCAN_AFTER_MISS, as before, while after[][] learns the new order. A slot's fingerprint is
+// taken again when it stops being one of the two in use, so a check later sees only a new frame.
+// Between frames it sleeps until FRAME_EARLY before the next one is due (the cameras run at
+// 90 fps, within a ms of each other), then looks every `poll_us`.
+#define FRAME_DUE (1.5 / 90)  // s: a camera that hasn't started a frame by then gets all its slots checked
+#define SCAN_AFTER_MISS 2.0    // s of checking all slots after a frame came in an unexpected one
+#define CAMS_IDLE 0.5          // s without a frame from either camera: look 4 times less often
+#define FRAME_EARLY 0.0025     // s before a frame is due to start looking for it
+
+// When to start looking for the next frame: FRAME_EARLY before the first camera's is due. A
+// camera already late (it lost its order, or stopped) means now.
+static double next_due(const double last[2], double t) {
+    double due = 1e300;
+    for (int cam = 0; cam < 2; cam++) {
+        double d = last[cam] + 1.0 / 90 - FRAME_EARLY;
+        if (t - last[cam] > CAMS_IDLE) continue;  // stopped: the other one sets the pace
+        if (d < due) due = d;
+    }
+    return due < 1e300 ? due : t;
+}
+
 static void poll_frames(int b, double seconds, int pid, void (*done)(const uint8_t *, int, double),
-                        int (*keep)(void)) {
+                        int (*keep)(void), unsigned poll_us) {
+    static const int order[2][8] = {{3, 0, 1, 2, 3, 0, 1, 2}, {7, 5, 4, 6, 5, 7, 6, 4}};
+    int after[EYE_SLOTS][EYE_SLOTS];
+    memset(after, -1, sizeof after);
+    for (int c = 0; c < 2; c++)
+        for (int i = 0; i < 8; i++) after[order[c][i]][order[c][(i + 1) % 8]] = order[c][(i + 2) % 8];
     uint64_t sig[EYE_SLOTS];
     double first[EYE_SLOTS];
     int cur[2] = {-1, -1}, prev[2] = {-1, -1};
     for (int k = 0; k < EYE_SLOTS; k++) sig[k] = frame_sig(bufs[b].p + slot_start(k)), first[k] = 0;
-    double start = now(), checked = start, kept = start;
+    double start = now(), checked = start, kept = start, last[2] = {start, start}, scan_until[2] = {0, 0};
     char proc[64];
     snprintf(proc, sizeof proc, "/proc/%d", pid);
     while ((seconds < 0 || now() - start < seconds) && !stop_rec) {
@@ -315,18 +349,36 @@ static void poll_frames(int b, double seconds, int pid, void (*done)(const uint8
             if (!keep()) return;
             kept = t;
         }
-        for (int k = 0; k < EYE_SLOTS; k++) {
+        for (int cam = 0; cam < 2; cam++) {
-            uint64_t s = frame_sig(bufs[b].p + slot_start(k));
+            int next = prev[cam] >= 0 ? after[prev[cam]][cur[cam]] : -1;
-            if (s == sig[k]) continue;
+            int all = next < 0 || t - last[cam] > FRAME_DUE || t < scan_until[cam];
-            sig[k] = s;
+            int from = all ? cam * 4 : next, to = all ? cam * 4 + 4 : next + 1;
-            int cam = k >= 4;
+            for (int k = from; k < to; k++) {
-            if (k == cur[cam] || k == prev[cam]) continue;  // landing, or a late burst
+                uint64_t s = frame_sig(bufs[b].p + slot_start(k));
-            if (prev[cam] >= 0) done(bufs[b].p + slot_start(prev[cam]), prev[cam], first[prev[cam]]);
+                if (s == sig[k]) continue;
-            prev[cam] = cur[cam];
+                sig[k] = s;
-            cur[cam] = k;
+                if (k == cur[cam] || k == prev[cam]) continue;  // landing, or a late burst
-            first[k] = t;
+                if (next >= 0 && k != next) scan_until[cam] = t + SCAN_AFTER_MISS;
+                if (prev[cam] >= 0) {
+                    done(bufs[b].p + slot_start(prev[cam]), prev[cam], first[prev[cam]]);
+                    after[prev[cam]][cur[cam]] = k;
+                    // Out of use from now on: later changes are a new frame.
+                    sig[prev[cam]] = frame_sig(bufs[b].p + slot_start(prev[cam]));
+                }
+                prev[cam] = cur[cam];
+                cur[cam] = k;
+                first[k] = t;
+                last[cam] = t;
+                next = prev[cam] >= 0 ? after[prev[cam]][cur[cam]] : -1;
+            }
         }
-        usleep(300);
+        double wait = poll_us * 1e-6;
+        if (t - last[0] > CAMS_IDLE && t - last[1] > CAMS_IDLE) {
+            wait *= 4;
+        } else if (next_due(last, t) - t > wait) {
+            wait = next_due(last, t) - t;
+        }
+        usleep((useconds_t)(wait * 1e6));
     }
 }
 
@@ -356,7 +408,7 @@ static int rec(double seconds, const char *dir, int pid) {
     pthread_t writer;
     pthread_create(&writer, NULL, ring_writer, NULL);
     double start = now();
-    poll_frames(b, seconds, pid, rec_frame, NULL);
+    poll_frames(b, seconds, pid, rec_frame, NULL, 300);  // 0.3 ms: recordings' times
     pthread_mutex_lock(&ring.mu);
     ring.done = 1;
     pthread_cond_signal(&ring.cv);
@@ -383,6 +435,10 @@ static int rec(double seconds, const char *dir, int pid) {
 #define SHARE_SLOTS 8
 #define SHARE_MAGIC 0x31434546u  // "FEC1"
 #define WANT_FRESH 3.0           // seconds a touch of the --want file lasts
+// How often --share looks for frames, with a timer slack that lets the kernel group the
+// wakeups: a frame reaches ft-eyes 1 to 1.5 ms after its camera starts the next, not 0.3.
+#define SHARE_POLL_US 1000
+#define SHARE_SLACK_NS 500000
 
 typedef struct {
     uint32_t magic, version, width, height, slots, entry_size;
@@ -462,6 +518,7 @@ static int share_loop(const char *path) {
                         .slots = SHARE_SLOTS, .entry_size = (uint32_t)esize};
     signal(SIGINT, on_stop);
     signal(SIGTERM, on_stop);
+    if (prctl(PR_SET_TIMERSLACK, SHARE_SLACK_NS, 0, 0, 0) != 0) perror("PR_SET_TIMERSLACK");
     fprintf(stderr, "ft-eyegrab: sharing frames in %s%s%s\n", path, want_path ? " while wanted by " : "",
             want_path ? want_path : "");
     int pid = -1, idle = -1, missing = 0;
@@ -486,7 +543,7 @@ static int share_loop(const char *path) {
         if (idle != 0 || missing) fprintf(stderr, "ft-eyegrab: copying frames from eyetracking %d\n", pid);
         idle = 0, missing = 0;
         h->tracker_pid = pid;
-        poll_frames(eye_buffer(), -1, pid, share_frame, wanted);
+        poll_frames(eye_buffer(), -1, pid, share_frame, wanted, SHARE_POLL_US);
         struct stat st;
         char proc[64];
         snprintf(proc, sizeof proc, "/proc/%d", pid);

gaze/tracker/ft-eyes

@@ -50,6 +50,7 @@ import json
 import math
 import mmap
 import os
+import select
 import socket
 import struct
 import sys
@@ -58,7 +59,12 @@ import time
 from collections import deque
 from pathlib import Path
 
-import numpy as np
+# One thread for numpy's BLAS and OpenMP, set before numpy loads: it would start one per core
+# (8 here) for small arrays that never need them. eyes_pupil keeps OpenCV to one as well.
+for _var in ("OPENBLAS_NUM_THREADS", "OMP_NUM_THREADS"):
+    os.environ.setdefault(_var, "1")
+
+import numpy as np  # noqa: E402
 
 sys.path.insert(0, str(Path(__file__).resolve().parent))
 import eyes_model  # noqa: E402
@@ -82,6 +88,15 @@ GAP = 3.0             # s without frames: the headset was off, and may sit diffe
 CLICK_BEFORE = 0.3    # a click's frames: the 300 ms before it (like the probe's fixation)
 CALIB_MIN = 15        # frames an eye needs in a calibration dot's window
 CALIB_SPREAD = 4.0    # px: more than this and the eye moved during the dot
+# Waiting for frames. They come only as a counter in shared memory, so there's nothing to block
+# on: sleep until a camera's next frame is due, then look every POLL. ft-eyegrab passes each one
+# on within a ms or two of when its camera starts the one after, so they arrive 11.1 ms apart,
+# give or take that.
+PERIOD = 1 / 90       # s between a camera's frames
+EARLY = 0.002         # start looking this long before a frame is due
+POLL = 0.001          # then this often until it comes
+STALLED = 0.1         # s without a frame: that camera stopped (headset off), and isn't waited for
+IDLE_POLL = 0.02      # how often to look while both are stopped
 
 
 class Cams:
@@ -352,7 +367,7 @@ def wait_for_cams(sock, tracker, want):
             return Cams()
         except (OSError, ValueError, RuntimeError):
             serve(sock, tracker)
-            time.sleep(0.2)
+            select.select([sock], [], [], 0.2)
 
 
 def serve(sock, tracker):
@@ -372,7 +387,24 @@ def serve(sock, tracker):
                 pass
 
 
+def below_steamvr():
+    """Nice 10 and SCHED_BATCH, for this thread and those it starts. ft-eyes runs in the dev
+    container's podman scope, where the gaze service's unit doesn't reach it, so it ran at
+    nice 0 on the cores vrcompositor and vrserver use. Batch also lets a waking ft-eyes wait
+    for the running task's turn instead of taking the core: a frame a few ms late costs the
+    gaze little, a late compositor frame costs a dropped frame in the headset."""
+    try:
+        os.setpriority(os.PRIO_PROCESS, 0, max(os.getpriority(os.PRIO_PROCESS, 0), 10))
+    except OSError as e:
+        print(f"ft-eyes: nice: {e}", file=sys.stderr, flush=True)
+    try:
+        os.sched_setscheduler(0, os.SCHED_BATCH, os.sched_param(0))
+    except (OSError, AttributeError) as e:
+        print(f"ft-eyes: SCHED_BATCH: {e}", file=sys.stderr, flush=True)
+
+
 def main():
+    below_steamvr()
     verbose = "-v" in sys.argv
     if "--watch-stdin" in sys.argv:
         # Run by ft-gazed through distrobox, which doesn't pass a stop on: quit when our
@@ -398,6 +430,7 @@ def main():
     print("ft-eyes: frames found, tracking", file=sys.stderr, flush=True)
     seen = [cams.count(0), cams.count(1)]
     report = time.monotonic()
+    arrived = [0.0, 0.0]  # when each camera's newest frame was seen (monotonic)
     while True:
         serve(sock, tracker)
         want()
@@ -407,6 +440,7 @@ def main():
             if n == seen[c]:
                 continue
             seen[c] = n
+            arrived[c] = time.monotonic()
             got = cams.frame(c, n - 1)  # only the newest: never fall behind
             if got:
                 eyes[c].feed(*got)
@@ -425,8 +459,6 @@ def main():
                     shifts += [float(v) for v in e.shift.value]
                     pupils += [e.gaze[3], e.gaze[4]] if fresh else [math.nan, math.nan]
                 out.write(latest, (yaw, pitch), flags, per, shifts, pupils)
-        else:
-            time.sleep(0.001)
         now = time.monotonic()
         if now - report >= 5:
             if verbose:
@@ -444,6 +476,12 @@ def main():
                 print("ft-eyes: frames went away; waiting", file=sys.stderr, flush=True)
                 cams = wait_for_cams(sock, tracker, want)
                 seen = [cams.count(0), cams.count(1)]
+        # Until the next frame is due (a command on the socket wakes us sooner).
+        wait = IDLE_POLL
+        for c in (0, 1):
+            if now - arrived[c] < STALLED:
+                wait = min(wait, max(arrived[c] + PERIOD - EARLY - now, POLL))
+        select.select([sock], [], [], wait)
 
 
 if __name__ == "__main__":

input-settings/ft_input_settings.py

@@ -15,6 +15,9 @@ to the input relay over its control socket (@frametop_relay):
   - Pointer: speed, dot size, distance and the rest, applied live.
   - Ignored panels: SteamVR overlays the pointer passes through (POINTER_IGNORE), by app or
     one by one. The helper lists them (@ft_pointer_helper "overlays").
+  - Game optimization: pausing Frametop while a VR game runs, so it leaves the CPU and GPU to the game
+    (input/game_pause.py, in the relay: "pause on|off|?"): pause now, pause by itself during VR
+    games, the controller gesture that pauses and resumes, what happens to the desktop, a sound.
   - Gaze: the pointer's gaze mode (@ft_pointer_helper "gaze") and the gaze service
     (gaze/ft-gazed, @ft_gazed: status, forget, reload), with its eye tracker (SteamVR's or
     our own) and eye bias (GAZE_TRACKER, GAZE_EYE in frametop.conf).
@@ -73,6 +76,7 @@ ACTION_LABELS = {
     "sens_down": "Slower pointer", "layout_reset": "Reset desktop screen layout",
     "screens_toggle": "Hide/show desktop screens", "keyboard_toggle": "Open/close keyboard",
     "float_toggle": "Float window in VR / put it back", "dock_all": "Put all floating windows back",
+    "pause_toggle": "Pause/resume Frametop (for VR games)",
     "key": "Pass through as key",
     "none": "Do nothing",
 }
@@ -95,6 +99,13 @@ CONTROLLER_BUTTONS = {
     "right/bumper": "Right bumper", "right/trigger": "Right trigger", "right/grip": "Right grip",
     "right/thumbstick": "Right stick click",
 }
+# Pausing for VR games (input/game_pause.py): the gesture a rules file without "pause_gesture" gets,
+# both thumbsticks clicked together twice, and what can happen to the desktop.
+DEFAULT_PAUSE_GESTURE = {"buttons": ["left/thumbstick", "right/thumbstick"], "presses": 2}
+PAUSE_DESKTOP_MODES = {"hide": "Hide it and slow it down (windows stay open)",
+                       "close": "Close it (windows close; it starts again when you resume)"}
+PAUSE_REASONS = {"game": "a VR game started", "gesture": "controller gesture", "command": "ft-pause",
+                 "settings": "from here"}
 # Gaze mode is a mouse and keyboard feature (docs/gaze-controllers.md; the relay's GAZE_ACTIONS).
 GAZE_ACTIONS = ("gaze_toggle", "gaze_precision", "gaze_drag", "gaze_left", "gaze_right", "gaze_quickcal")
 CONTROLLER_ACTIONS = [a for a in ACTION_LABELS if a not in ("key", "none") + GAZE_ACTIONS]
@@ -293,6 +304,7 @@ class Backend(QObject):
     gazeChanged = Signal()
     driverChanged = Signal()
     panelsChanged = Signal()
+    pauseChanged = Signal()
     activity = Signal(str)  # device id
     captured = Signal(int, str)  # code, name
     capturedController = Signal(str, str)  # button, label
@@ -320,6 +332,8 @@ class Backend(QObject):
         self._check_asked = 0.0  # when quickcal or calibrate went to the gaze service (its errors)
         self._driver_block = ""  # set by _check_driver
         self._panels = None  # SteamVR's overlays, from the helper; None until it answers
+        self._pause = {}  # the relay's pause state ("pause ?"), {} when it doesn't answer
+        self._pause_at = 0.0
         self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
         self.sock.bind("")  # autobind an abstract address the relay can reply to
         self.sock.setblocking(False)
@@ -352,6 +366,7 @@ class Backend(QObject):
 
     def _refresh(self):
         self._send("devices")
+        self._send("pause ?")
         self._send("vrstatus", HELPER)
         self._send("gaze ?", HELPER)
         if not self._send("status", GAZED) and self._gaze:
@@ -365,6 +380,9 @@ class Backend(QObject):
         if self._gaze_mode is not None and now - self._gaze_at > 5:
             self._gaze_mode = None
             self.gazeChanged.emit()
+        if self._pause and now - self._pause_at > 5:
+            self._pause = {}
+            self.pauseChanged.emit()
 
     def _check_driver(self):
         block = driver_block()
@@ -403,13 +421,20 @@ class Backend(QObject):
             if t == "devices":
                 self._nodes = msg.get("nodes", [])
                 self._pointer_mode = bool(msg.get("pointer_mode"))
-                self._relay_ok = True
+                was_ok, self._relay_ok = self._relay_ok, True
+                if not was_ok:
+                    self.pauseChanged.emit()  # (pauseStatus' "old")
                 self.devicesChanged.emit()
             elif t == "overlays":
                 panels = [o for o in msg.get("list", []) if isinstance(o, dict) and isinstance(o.get("key"), str)]
                 if panels != self._panels:
                     self._panels = panels
                     self.panelsChanged.emit()
+            elif t == "pause":
+                self._pause_at = time.monotonic()
+                if msg != self._pause:
+                    self._pause = msg
+                    self.pauseChanged.emit()
             elif t == "vrstatus":
                 self._vr = msg
                 self._vr_at = time.monotonic()
@@ -817,6 +842,108 @@ class Backend(QObject):
         else:
             self.message.emit("The pointer helper isn't running (frametop-pointer.service)", True)
 
+    # --- pausing for VR games ---
+    @Property("QVariantMap", notify=pauseChanged)
+    def pauseStatus(self):
+        """The relay's pause state, and a line saying it ("relay": False when it doesn't answer)."""
+        st = self._pause
+        if not st:
+            # "old": the relay answers, but not about pausing (it predates it).
+            return {"relay": False, "old": self._relay_ok, "paused": False,
+                    "summary": "Unknown: the input relay " + ("can't pause" if self._relay_ok else "isn't answering")}
+        if st.get("paused"):
+            reason = PAUSE_REASONS.get(st.get("reason"), st.get("reason") or "")
+            summary = f"Paused since {time.strftime('%H:%M', time.localtime(st.get('since') or time.time()))}"
+            summary += f" ({reason})" if reason else ""
+            if st.get("ends_with_game"):
+                summary += ", until the game ends"
+        else:
+            summary = "Running" + (", with a VR game" if st.get("game") else "")
+        if st.get("busy"):
+            summary += "; working on it…"
+        return {"relay": True, "paused": bool(st.get("paused")), "summary": summary,
+                "gestureReader": bool(st.get("gesture_reader"))}
+
+    @Slot(bool)
+    def setPaused(self, on):
+        if self._send(f"pause {'on' if on else 'off'} settings"):
+            QTimer.singleShot(300, self._refresh)
+        else:
+            self.message.emit("The input relay isn't running (frametop-input-relay.service)", True)
+
+    def _set_rule(self, key, value, text):
+        rules = read_json(RULES_PATH)
+        rules[key] = value
+        self._save_rules(rules)
+        self.message.emit(text, False)
+
+    @Property(bool, notify=mappingsChanged)
+    def pauseAuto(self):
+        return read_json(RULES_PATH).get("pause_auto", True) is not False
+
+    @Slot(bool)
+    def setPauseAuto(self, on):
+        self._set_rule("pause_auto", bool(on), "VR games pause Frametop" if on else "VR games no longer pause Frametop")
+
+    @Property("QVariantList", constant=True)
+    def pauseDesktopModes(self):
+        return [{"value": k, "text": v} for k, v in PAUSE_DESKTOP_MODES.items()]
+
+    @Property(str, notify=mappingsChanged)
+    def pauseDesktop(self):
+        mode = read_json(RULES_PATH).get("pause_desktop")
+        return mode if mode in PAUSE_DESKTOP_MODES else "hide"
+
+    @Slot(str)
+    def setPauseDesktop(self, mode):
+        if mode in PAUSE_DESKTOP_MODES:
+            self._set_rule("pause_desktop", mode, "Paused, the desktop: " + PAUSE_DESKTOP_MODES[mode].split(" (")[0].lower())
+
+    @Property(bool, notify=mappingsChanged)
+    def pauseSound(self):
+        return read_json(RULES_PATH).get("pause_sound", True) is not False
+
+    @Slot(bool)
+    def setPauseSound(self, on):
+        self._set_rule("pause_sound", bool(on), "A sound on pause and resume" if on else "No sound on pause and resume")
+
+    @Property("QVariantList", constant=True)
+    def gestureButtons(self):
+        return [{"value": "", "text": "None"}] + [{"value": b, "text": label} for b, label in CONTROLLER_BUTTONS.items()]
+
+    @Property("QVariantMap", notify=mappingsChanged)
+    def pauseGesture(self):
+        """{"first", "second" ("" for none), "presses"} (the relay's game_pause.gesture_of)."""
+        spec = read_json(RULES_PATH).get("pause_gesture", DEFAULT_PAUSE_GESTURE)
+        buttons = [b for b in (spec or {}).get("buttons", []) if b in CONTROLLER_BUTTONS][:2] \
+            if isinstance(spec, dict) and isinstance(spec.get("buttons"), list) else []
+        presses = 1 if len(buttons) == 2 and spec.get("presses") == 1 else 2
+        return {"first": buttons[0] if buttons else "", "second": buttons[1] if len(buttons) > 1 else "",
+                "presses": presses}
+
+    @Slot(str, str, int)
+    def setPauseGesture(self, first, second, presses):
+        """No first button: no gesture. One button always takes two presses."""
+        buttons = list(dict.fromkeys(b for b in (first, second) if b in CONTROLLER_BUTTONS))
+        if not buttons:
+            self._set_rule("pause_gesture", None, "No controller gesture pauses Frametop")
+            return
+        presses = 1 if len(buttons) == 2 and presses == 1 else 2
+        self._set_rule("pause_gesture", {"buttons": buttons, "presses": presses},
+                       "Pause gesture: " + self.gestureText(buttons, presses))
+
+    @staticmethod
+    def gestureText(buttons, presses):
+        names = " and ".join(CONTROLLER_BUTTONS[b] for b in buttons)
+        together = " together" if len(buttons) == 2 else ""
+        return f"{names}{together}, {'twice' if presses == 2 else 'once'}"
+
+    @Property(str, notify=mappingsChanged)
+    def pauseGestureText(self):
+        g = self.pauseGesture
+        buttons = [b for b in (g["first"], g["second"]) if b]
+        return self.gestureText(buttons, g["presses"]) if buttons else "None"
+
     # --- gaze ---
     def _gaze_status(self, status):
         now = time.monotonic()
@@ -1036,6 +1163,12 @@ class Backend(QObject):
         else:
             self.message.emit("The gaze service isn't running (frametop-gaze.service)", True)
 
+    @Slot()
+    def keepGazeAwake(self):
+        """The Gaze page is open: the gaze service doesn't idle meanwhile (its status stays live,
+        and a check opens without waiting for the tracker). The page renews this every 10 s."""
+        self._send("wake 30", GAZED)
+
     @Slot()
     def gazeQuickCheck(self):
         """The gaze service's one-dot check, in the panel fixed to the headset."""

input-settings/main.qml

@@ -19,6 +19,7 @@ Kirigami.ApplicationWindow {
             Kirigami.Action { text: "Devices"; icon.name: "input-mouse"; onTriggered: root.show(devicesPage) },
             Kirigami.Action { text: "Buttons"; icon.name: "input-keyboard"; onTriggered: root.show(buttonsPage) },
             Kirigami.Action { text: "Controllers"; icon.name: "input-gamepad"; onTriggered: root.show(controllersPage) },
+            Kirigami.Action { text: "Game optimization"; icon.name: "applications-games"; onTriggered: root.show(gamesPage) },
             Kirigami.Action { text: "Keyboard"; icon.name: "input-keyboard-virtual"; onTriggered: root.show(keyboardPage) },
             Kirigami.Action { text: "Pointer"; icon.name: "transform-move"; onTriggered: root.show(pointerPage) },
             Kirigami.Action { text: "Ignored panels"; icon.name: "view-hidden"; onTriggered: root.show(ignorePage) },
@@ -56,8 +57,8 @@ Kirigami.ApplicationWindow {
         pageStack.push(page)
     }
 
-    // FT_INPUT_PAGE=buttons|controllers|keyboard|pointer|ignore|gaze|bluetooth opens the app on that page.
+    // FT_INPUT_PAGE=buttons|controllers|games (Game optimization)|keyboard|pointer|ignore|gaze|bluetooth opens the app on that page.
-    pageStack.initialPage: ({ buttons: buttonsPage, controllers: controllersPage, keyboard: keyboardPage,
+    pageStack.initialPage: ({ buttons: buttonsPage, controllers: controllersPage, games: gamesPage, keyboard: keyboardPage,
                               pointer: pointerPage, ignore: ignorePage, gaze: gazePage,
                               bluetooth: bluetoothPage })[startPage] || devicesPage
 
@@ -826,6 +827,140 @@ Kirigami.ApplicationWindow {
         }
     }
 
+    // ---------------------------------------------------------------- Games
+    Component {
+        id: gamesPage
+        Kirigami.ScrollablePage {
+            id: gmpage
+            title: "Game optimization"
+            property var st: backend.pauseStatus
+
+            // The gesture's boxes follow the saved gesture (which may tidy what was picked).
+            function syncGesture() {
+                const g = backend.pauseGesture
+                firstBox.currentIndex = firstBox.indexOfValue(g.first)
+                secondBox.currentIndex = secondBox.indexOfValue(g.second)
+                pressBox.currentIndex = pressBox.indexOfValue(g.presses)
+            }
+            function saveGesture() {
+                backend.setPauseGesture(firstBox.currentValue, secondBox.currentValue, pressBox.currentValue)
+            }
+            Component.onCompleted: syncGesture()
+            Connections {
+                target: backend
+                function onMappingsChanged() { gmpage.syncGesture() }
+            }
+
+            ColumnLayout {
+                spacing: Kirigami.Units.largeSpacing
+
+                Kirigami.InlineMessage {
+                    Layout.fillWidth: true
+                    visible: !gmpage.st.relay
+                    type: Kirigami.MessageType.Error
+                    text: gmpage.st.old
+                          ? "The input relay that runs is older and can't pause. Restart it: "
+                            + "systemctl --user restart frametop-input-relay"
+                          : "The input relay isn't answering (frametop-input-relay.service). It does the pausing."
+                }
+
+                Kirigami.FormLayout {
+                    Layout.fillWidth: true
+
+                    RowLayout {
+                        Kirigami.FormData.label: "Frametop:"
+                        Controls.Label { text: gmpage.st.summary }
+                        Controls.Button {
+                            text: gmpage.st.paused ? "Resume" : "Pause now"
+                            icon.name: gmpage.st.paused ? "media-playback-start" : "media-playback-pause"
+                            enabled: gmpage.st.relay
+                            onClicked: backend.setPaused(!gmpage.st.paused)
+                        }
+                    }
+                    Controls.Switch {
+                        Kirigami.FormData.label: "VR games:"
+                        text: "Pause while a VR game runs, and resume when it ends"
+                        checked: backend.pauseAuto
+                        onToggled: backend.setPauseAuto(checked)
+                    }
+
+                    Kirigami.Separator { Kirigami.FormData.isSection: true; Kirigami.FormData.label: "Controller gesture" }
+                    Controls.ComboBox {
+                        id: firstBox
+                        Kirigami.FormData.label: "Button:"
+                        model: backend.gestureButtons
+                        textRole: "text"
+                        valueRole: "value"
+                        Layout.preferredWidth: Kirigami.Units.gridUnit * 10
+                        onActivated: gmpage.saveGesture()
+                    }
+                    Controls.ComboBox {
+                        id: secondBox
+                        Kirigami.FormData.label: "Together with:"
+                        model: backend.gestureButtons
+                        textRole: "text"
+                        valueRole: "value"
+                        enabled: firstBox.currentValue !== ""
+                        Layout.preferredWidth: Kirigami.Units.gridUnit * 10
+                        onActivated: gmpage.saveGesture()
+                    }
+                    Controls.ComboBox {
+                        id: pressBox
+                        Kirigami.FormData.label: "Pressed:"
+                        model: [{ value: 2, text: "Twice" }, { value: 1, text: "Once" }]
+                        textRole: "text"
+                        valueRole: "value"
+                        // One button pressed once would go off far too easily in games.
+                        enabled: firstBox.currentValue !== "" && secondBox.currentValue !== ""
+                        Layout.preferredWidth: Kirigami.Units.gridUnit * 10
+                        onActivated: gmpage.saveGesture()
+                    }
+                    Controls.Label {
+                        Layout.fillWidth: true
+                        wrapMode: Text.Wrap
+                        opacity: 0.7
+                        text: (backend.pauseGesture.first === "" ? "No gesture: a mapped button, a key combination, or ft-pause still work."
+                               : "Pauses and resumes Frametop, in games too. The game still gets the presses, so pick buttons it "
+                                 + "doesn't use this way. Two buttons count as together when both go down within a third of a "
+                                 + "second, and twice means within 0.7 s.")
+                              + (gmpage.st.relay && backend.pauseGesture.first !== "" && !gmpage.st.gestureReader
+                                 ? " Not reading the controllers right now (SteamVR isn't running?)." : "")
+                    }
+
+                    Kirigami.Separator { Kirigami.FormData.isSection: true; Kirigami.FormData.label: "While paused" }
+                    Controls.ComboBox {
+                        Kirigami.FormData.label: "The desktop:"
+                        model: backend.pauseDesktopModes
+                        textRole: "text"
+                        valueRole: "value"
+                        Layout.preferredWidth: Kirigami.Units.gridUnit * 20
+                        Component.onCompleted: currentIndex = indexOfValue(backend.pauseDesktop)
+                        onActivated: backend.setPauseDesktop(currentValue)
+                    }
+                    Controls.Switch {
+                        Kirigami.FormData.label: "Sound:"
+                        text: "Play a sound on pause and resume"
+                        checked: backend.pauseSound
+                        onToggled: backend.setPauseSound(checked)
+                    }
+                }
+
+                Controls.Label {
+                    Layout.fillWidth: true
+                    wrapMode: Text.Wrap
+                    opacity: 0.7
+                    text: "Paused, Frametop leaves the headset's CPU and GPU to the game. The gaze service and our eye "
+                          + "tracker stop, and nothing reads SteamVR's eye tracking. Hand tracking and remote desktop stop "
+                          + "if they run. The desktop hides and slows down, or closes, as chosen above. The 3D mouse lets go, "
+                          + "so the mouse is a plain one for SteamVR. Mapped buttons and key combinations do nothing but "
+                          + "pausing, the Steam menu, and your own commands. Resuming brings back what pausing stopped. "
+                          + "Map \"Pause/resume Frametop\" to a button or key combination on the other pages, or run "
+                          + "input/ft-pause."
+                }
+            }
+        }
+    }
+
     // ---------------------------------------------------------------- Gaze
     Component {
         id: gazePage
@@ -834,6 +969,14 @@ Kirigami.ApplicationWindow {
             title: "Gaze"
             header: DriverWarning {}
             property var status: backend.gazeStatus
+            // The gaze service idles while the gaze isn't used; open, this page keeps it going.
+            Timer {
+                running: true
+                repeat: true
+                interval: 10000
+                triggeredOnStart: true
+                onTriggered: backend.keepGazeAwake()
+            }
             actions: [
                 Kirigami.Action {
                     text: "Quick check"
@@ -1067,7 +1210,8 @@ Kirigami.ApplicationWindow {
                 Controls.Label {
                     Kirigami.FormData.label: "Service:"
                     text: backend.gazeServiceRunning
-                          ? (gpage.status.ft_gaze ? "running" : "running, eye tracker reader restarting")
+                          ? (gpage.status.awake === false ? "idle: " + gpage.status.idle + " (it starts when the gaze is used)"
+                             : gpage.status.ft_gaze ? "running" : "running, eye tracker reader starting")
                           : backend.gazeServiceInstalled ? "not running (frametop-gaze.service, starts with SteamVR)"
                           : "not installed: run gaze/run.sh install in the Frametop folder, in a terminal"
                     color: backend.gazeServiceRunning ? Kirigami.Theme.textColor : Kirigami.Theme.negativeTextColor

input/ft-pause

@@ -0,0 +1,45 @@
+#!/usr/bin/python3
+"""ft-pause: pause Frametop for a VR game, so it leaves the CPU and GPU to the game, or resume it.
+
+  ft-pause on|off|toggle   pause or resume (input/game_pause.py has what pausing stops)
+  ft-pause status          the pause state, as JSON (the default)
+
+The input relay does it (frametop-input-relay.service). So do the pause_toggle action, the
+controller gesture (by default both thumbsticks clicked together twice), and, with auto pause on,
+a VR game starting; Frametop Input Settings has the settings, on its Game optimization page.
+"""
+
+import json
+import os
+import socket
+import sys
+
+
+def ask(msg, timeout=2.0):
+    s = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM | socket.SOCK_CLOEXEC)
+    s.bind(f"\0ft_pause.{os.getpid()}")
+    s.settimeout(timeout)
+    try:
+        s.sendto(msg.encode(), "\0frametop_relay")
+        return json.loads(s.recv(65536))
+    except ConnectionRefusedError:
+        sys.exit("the input relay isn't running (frametop-input-relay.service)")
+    except (socket.timeout, ValueError):
+        sys.exit("no answer from the input relay (an older one, without pausing?)")
+    finally:
+        s.close()
+
+
+def main():
+    cmd = sys.argv[1] if len(sys.argv) > 1 else "status"
+    if cmd in ("on", "off", "toggle"):
+        r = ask(f"pause {cmd} command")
+        print("Frametop paused" if r.get("paused") else "Frametop running")
+    elif cmd == "status":
+        print(json.dumps(ask("pause ?"), indent=1))
+    else:
+        sys.exit(__doc__)
+
+
+if __name__ == "__main__":
+    main()

input/game_pause.py

@@ -0,0 +1,483 @@
+"""Pause Frametop for VR games, so it leaves the headset's CPU and GPU to the game. The input
+relay (input-relay.py) runs this: it's the one part of Frametop that always runs.
+
+Paused:
+  - The gaze service stops (frametop-gaze: ft-gazed, ft-gaze, our own eye tracker ft-eyes, the
+    gaze panel), and with it every read of SteamVR's eye tracking. Our frame grabber, the root
+    service ft-eyegrab, goes idle by itself 3 seconds after ft-eyes stops asking for frames.
+  - Hand tracking stops if it runs (frametop-camd, frametop-hands).
+  - The desktop, by "pause_desktop": "hide" (the default) hides every screen and floating window
+    and slows the desktop down ("pause on" to ft-screens: KWin gets one frame callback a second
+    instead of 90, so it and the apps on it hardly draw), and remote desktop stops if it runs
+    (session/remote-ctl.sh: krdp, Xvnc, FreeRDP). Windows stay open. "close" closes the desktop
+    (desktops.sh stop): its windows close, and resuming starts it again (about 12 seconds), in
+    its start profile if it has one.
+  - In the relay: the 3D mouse lets go and the mouse is a plain mouse for SteamVR, typing goes to
+    Steam, and mapped buttons and key combinations do nothing but PAUSED_ACTIONS and commands.
+Resuming starts again only what pausing stopped. The pointer helper and ft-powerd keep running:
+they cost little, and the helper is what says a VR game started.
+
+Toggled by:
+  - The pause_toggle action: a mouse button, a key combination, or a controller button outside
+    games (the pointer helper only reads those outside games).
+  - A controller gesture, by default both thumbsticks clicked together twice ("pause_gesture").
+    It's read from vrserver's web socket (vrws.py), which works in games and takes nothing from
+    them, so the game sees the clicks too.
+  - input/ft-pause on|off|toggle|status, which uses the relay's control socket
+    ("pause on|off|toggle|?").
+  - VR games, with "pause_auto" (on by default): the pointer helper says "vrgame 1|0" as a SteamVR
+    scene app starts and ends (and every 5 seconds). A game starting pauses; a pause that starts
+    while a game runs ends RESUME_DELAY after the game does, unless another game starts first.
+    Toggled back on during a game, Frametop stays on until that game ends. A pause that starts
+    outside a game lasts until it's toggled off.
+
+Settings in ~/.config/frametop-input.json (Frametop Input Settings, Game optimization page): "pause_auto"
+(bool), "pause_gesture" ({"buttons": one or two controller buttons, "presses": 1 or 2}, or null
+for none; one button always takes two presses), "pause_desktop" ("hide" or "close"), and
+"pause_sound" (a sound on pause and resume; bool). The state outlives a relay restart in
+STATE_PATH.
+"""
+import json
+import os
+import queue
+import socket
+import subprocess
+import threading
+import time
+
+import vrws
+
+REPO = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+DESKTOPS = os.path.join(REPO, "desktops.sh")
+REMOTE_CTL = os.path.join(REPO, "session", "remote-ctl.sh")
+RELAY = "\0frametop_relay"
+SCREENS = "\0ft_screens"
+STATE_PATH = f"/run/user/{os.getuid()}/frametop-pause.json"
+# User services that pausing stops, if they run.
+UNITS = ("frametop-gaze.service", "frametop-hands.service", "frametop-camd.service")
+# What still works while paused, besides commands ("command:CMD"): the toggle itself, and Steam's menu.
+PAUSED_ACTIONS = ("pause_toggle", "steam_menu")
+DEFAULT_GESTURE = {"buttons": ["left/thumbstick", "right/thumbstick"], "presses": 2}
+DESKTOP_MODES = ("hide", "close")
+SOUNDS = {True: "/usr/share/sounds/ocean/stereo/device-removed.oga",
+          False: "/usr/share/sounds/ocean/stereo/device-added.oga"}
+RESUME_DELAY = 5.0  # after a VR game ends: loading the next one can end one scene app and start another
+GAME_STALE = 12.0  # the helper repeats "vrgame" every 5 s; silence this long means no game (or no SteamVR)
+CHORD_WINDOW = 0.3  # a two-button gesture's buttons go down within this of each other
+DOUBLE_WINDOW = 0.7  # a double press's second press comes within this of the first
+
+
+def gesture_of(rules, buttons):
+    """The rules' pause gesture as (buttons, presses), or None for none. `buttons` are the
+    controller buttons there are (the relay's VR_BUTTONS)."""
+    spec = rules.get("pause_gesture", DEFAULT_GESTURE)
+    if not isinstance(spec, dict) or not isinstance(spec.get("buttons"), list):
+        return None
+    chosen = tuple(dict.fromkeys(b for b in spec["buttons"] if b in buttons))[:2]
+    if not chosen:
+        return None
+    return chosen, 1 if len(chosen) == 2 and spec.get("presses") == 1 else 2
+
+
+def settings_of(rules, buttons):
+    return {"auto": rules.get("pause_auto", True) is not False,
+            "gesture": gesture_of(rules, buttons),
+            "desktop": rules.get("pause_desktop") if rules.get("pause_desktop") in DESKTOP_MODES else "hide",
+            "sound": rules.get("pause_sound", True) is not False}
+
+
+class Gesture:
+    """The pause gesture, from button presses and releases. A press of a two-button gesture is
+    both buttons going down within CHORD_WINDOW of each other, so a button held for a while (to
+    sprint, say) and the other clicked doesn't count. Two presses within DOUBLE_WINDOW make a
+    double press."""
+
+    def __init__(self, buttons, presses):
+        self.buttons, self.presses = tuple(buttons), presses
+        self.down = {}  # button -> when it went down
+        self.first = None  # when the first press of a double press was
+        self.fired = None
+
+    def reset(self):
+        self.down.clear()
+        self.first = None
+
+    def feed(self, button, pressed, now):
+        """A button's state; True when it completes the gesture."""
+        if button not in self.buttons:
+            return False
+        if not pressed:
+            self.down.pop(button, None)
+            return False
+        if button in self.down:
+            return False  # still down
+        self.down[button] = now
+        if len(self.down) < len(self.buttons) or now - min(self.down.values()) > CHORD_WINDOW:
+            return False
+        if self.presses == 2 and (self.first is None or now - self.first > DOUBLE_WINDOW):
+            self.first = now
+            return False
+        self.first = None
+        if self.fired is not None and now - self.fired < 1.0:
+            return False  # a triple press is still one
+        self.fired = now
+        return True
+
+
+class ControllerWatch(threading.Thread):
+    """Follows the Frame controllers on vrserver's web socket for the pause gesture, and sends
+    the relay "pause toggle gesture" when it's made. Reconnects every 5 seconds while SteamVR
+    is away. With no gesture set, it doesn't connect."""
+
+    def __init__(self, log):
+        super().__init__(name="pause-gesture", daemon=True)
+        self.log = log
+        self.lock = threading.Lock()
+        self.gesture = None
+        self.changed = threading.Event()
+        self.connected = False
+        self.sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+
+    def set_gesture(self, spec):
+        """(buttons, presses), or None for no gesture."""
+        with self.lock:
+            g = self.gesture
+            if spec is None:
+                self.gesture = None
+            elif g is None or (g.buttons, g.presses) != spec:
+                self.gesture = Gesture(*spec)
+        self.changed.set()
+
+    def current(self):
+        with self.lock:
+            return self.gesture
+
+    def run(self):
+        while True:
+            if self.current() is None:
+                if self.connected:
+                    self.log("pause gesture: none set, stopped reading the controllers")
+                self.connected = False
+                self.changed.wait()
+                self.changed.clear()
+                continue
+            try:
+                self.session()
+            except (OSError, ValueError) as e:  # urllib's errors are OSErrors
+                if self.connected:
+                    self.log(f"pause gesture: SteamVR's web socket went away ({e}); retrying")
+                self.connected = False
+            self.changed.wait(5)
+            self.changed.clear()
+
+    def session(self):
+        ws = vrws.VrSocket()
+        try:
+            ws.open(f"frametop_pause_{os.getpid()}")
+            sides = {}  # root path -> side
+            next_poll = 0.0
+            while True:
+                g = self.current()
+                if g is None:
+                    return
+                now = time.monotonic()
+                if now >= next_poll:
+                    # A controller connects later, or changes its root path when the 3D mouse's
+                    # virtual controller takes or gives back its hand role.
+                    next_poll = now + 3.0
+                    found = vrws.controllers()
+                    if found != sides:
+                        for path in sides.keys() - found.keys():
+                            ws.subscribe(path, on=False)
+                        for path in found.keys() - sides.keys():
+                            ws.subscribe(path)
+                        sides = found
+                        g.reset()
+                    if not self.connected:
+                        self.connected = True
+                        self.log(f"pause gesture: following {' and '.join(sorted(sides.values())) or 'no'} "
+                                 f"controller{'s' if len(sides) != 1 else ''} on SteamVR's web socket")
+                wanted = {b: (b.split("/", 1)[0], f"/input/{b.split('/', 1)[1]}/click") for b in g.buttons}
+                for text in ws.messages(timeout=1.0):
+                    # About 160 messages a second, nearly all capacitive sensing: parse only the
+                    # few that carry one of the gesture's buttons.
+                    if not any(c in text for _, c in wanted.values()):
+                        continue
+                    try:
+                        msg = json.loads(text)
+                    except ValueError:
+                        continue
+                    side = sides.get(msg.get("device"))
+                    components = msg.get("components") or {}
+                    for button, (s, component) in wanted.items():
+                        if s == side and component in components:
+                            if g.feed(button, bool(components[component]), time.monotonic()):
+                                self.log("pause gesture")
+                                try:
+                                    self.sock.sendto(b"pause toggle gesture", RELAY)
+                                except OSError:
+                                    pass
+        finally:
+            ws.close()
+
+
+def run(cmd, timeout=30):
+    """A command's exit status (None if it couldn't run), its output going nowhere."""
+    try:
+        return subprocess.run(cmd, stdin=subprocess.DEVNULL, stdout=subprocess.DEVNULL,
+                              stderr=subprocess.DEVNULL, timeout=timeout).returncode
+    except (OSError, subprocess.TimeoutExpired):
+        return None
+
+
+def output(cmd, timeout=10):
+    try:
+        return subprocess.run(cmd, stdin=subprocess.DEVNULL, capture_output=True, text=True,
+                              timeout=timeout).stdout
+    except (OSError, subprocess.TimeoutExpired):
+        return ""
+
+
+def active(unit):
+    return run(["systemctl", "--user", "-q", "is-active", unit], timeout=10) == 0
+
+
+def desktop_running():
+    return run(["pgrep", "-x", "ft-screens"], timeout=5) == 0
+
+
+class Worker(threading.Thread):
+    """Does the slow part of pausing and resuming, in order, one job at a time: stopping and
+    starting services, remote desktop, and closing or starting the desktop. `stopped` is what
+    the last pause stopped, for the resume to start again."""
+
+    def __init__(self, log, save):
+        super().__init__(name="pause-worker", daemon=True)
+        self.log, self.save = log, save
+        self.jobs = queue.Queue()
+        self.lock = threading.Lock()
+        self.stopped = {"units": [], "remote": False, "desktop": None}
+        self.busy = False
+
+    def submit(self, job, *args):
+        self.busy = True
+        self.jobs.put((job, args))
+
+    def run(self):
+        while True:
+            job, args = self.jobs.get()
+            try:
+                job(*args)
+            except Exception as e:  # one failure mustn't stop the next pause or resume
+                self.log(f"pause: {job.__name__} failed: {e!r}")
+            self.busy = not self.jobs.empty()
+            self.save()
+
+    def snapshot(self):
+        with self.lock:
+            return {"units": list(self.stopped["units"]), "remote": self.stopped["remote"],
+                    "desktop": self.stopped["desktop"]}
+
+    def restore(self, stopped):
+        with self.lock:
+            self.stopped = {"units": [u for u in stopped.get("units", []) if u in UNITS],
+                            "remote": bool(stopped.get("remote")),
+                            "desktop": stopped.get("desktop") if stopped.get("desktop") in ("hidden", "closed") else None}
+
+    def stop_units(self):
+        """Stop the UNITS that run, adding them to what the resume starts again."""
+        units = [u for u in UNITS if active(u)]
+        if units:
+            run(["systemctl", "--user", "stop", *units], timeout=30)
+            with self.lock:
+                self.stopped["units"] += [u for u in units if u not in self.stopped["units"]]
+            self.log(f"pause: stopped {', '.join(units)}")
+
+    def pause(self, desktop):
+        if desktop == "close":
+            if desktop_running():
+                run([DESKTOPS, "stop"], timeout=40)  # remote desktop goes with it
+                with self.lock:
+                    self.stopped["desktop"] = "closed"
+                self.log("pause: desktop closed")
+        else:
+            if "running=1" in output([REMOTE_CTL, "status"]):
+                run([REMOTE_CTL, "stop"])
+                with self.lock:
+                    self.stopped["remote"] = True
+                self.log("pause: remote desktop stopped")
+            with self.lock:
+                self.stopped["desktop"] = "hidden"  # ft-screens was told already (or isn't running)
+        self.stop_units()
+
+    def enforce(self):
+        """While paused: SteamVR restarted, and started the gaze service with it."""
+        self.stop_units()
+
+    def resume(self):
+        stopped = self.snapshot()
+        units = stopped["units"]
+        if units:
+            # They need SteamVR (Requisite=steamvr.service): without it they start with it next time.
+            if run(["systemctl", "--user", "start", *units], timeout=30) == 0:
+                self.log(f"resume: started {', '.join(units)}")
+            else:
+                self.log(f"resume: couldn't start {', '.join(units)} (SteamVR not running?)")
+        if stopped["remote"]:
+            # In a scope of its own, not this service's, so a relay restart doesn't end it.
+            run(["systemd-run", "--user", "--scope", "--collect", "--quiet", REMOTE_CTL, "start"])
+            self.log("resume: remote desktop started")
+        if stopped["desktop"] == "closed":
+            if run([DESKTOPS, "start"], timeout=60) == 0:
+                self.log("resume: desktop started")
+            else:
+                self.log("resume: the desktop didn't start (see /tmp/frametop-session.log)")
+        with self.lock:
+            self.stopped = {"units": [], "remote": False, "desktop": None}
+
+
+class GamePause:
+    """The pause state, its automatic side, and the relay's way in. `on_change(paused)` is
+    called (from the relay's thread) when the state flips, for the relay's own part."""
+
+    def __init__(self, log, on_change, buttons):
+        self.log, self.on_change, self.buttons = log, on_change, buttons
+        self.lock = threading.Lock()  # the state file, written from both threads
+        self.paused = False
+        self.reason = ""  # what paused it: gesture, button, key, controller, command, game
+        self.since = 0.0  # wall clock
+        self.ends_with_game = False  # resume when the VR game ends
+        self.game = False
+        self.game_seen = 0.0  # last "vrgame" from the helper
+        self.resume_at = None
+        self.settings = settings_of({}, buttons)
+        self.screens = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM | socket.SOCK_NONBLOCK)
+        self.worker = Worker(log, self.save)
+        self.watch = ControllerWatch(log)
+        self.worker.start()
+        self.watch.start()
+        self.load()
+
+    # --- state file ---
+    def save(self):
+        with self.lock:
+            state = {"paused": self.paused, "reason": self.reason, "since": self.since,
+                     "ends_with_game": self.ends_with_game, "stopped": self.worker.snapshot()}
+            try:
+                tmp = STATE_PATH + ".tmp"
+                with open(tmp, "w") as f:
+                    json.dump(state, f)
+                os.replace(tmp, STATE_PATH)
+            except OSError as e:
+                self.log(f"pause: can't save {STATE_PATH}: {e}")
+
+    def load(self):
+        """A relay restarted while paused stays paused (the relay's part is applied by its first
+        configure)."""
+        try:
+            with open(STATE_PATH) as f:
+                state = json.load(f)
+        except (OSError, ValueError):
+            return
+        if not isinstance(state, dict) or not state.get("paused"):
+            return
+        self.paused = True
+        self.reason = str(state.get("reason", ""))
+        self.since = float(state.get("since", 0) or 0)
+        self.ends_with_game = bool(state.get("ends_with_game"))
+        self.worker.restore(state.get("stopped") or {})
+        self.log(f"paused since before this relay started ({self.reason})")
+        self.worker.submit(self.worker.enforce)
+
+    # --- settings ---
+    def configure(self, rules):
+        self.settings = settings_of(rules, self.buttons)
+        self.watch.set_gesture(self.settings["gesture"])
+        if not self.settings["auto"]:
+            self.ends_with_game, self.resume_at = False, None
+
+    # --- pausing and resuming ---
+    def sound(self, paused):
+        if self.settings["sound"] and os.path.exists(SOUNDS[paused]):
+            try:
+                subprocess.Popen(["pw-play", SOUNDS[paused]], stdin=subprocess.DEVNULL, stdout=subprocess.DEVNULL,
+                                 stderr=subprocess.DEVNULL, start_new_session=True)
+            except OSError:
+                pass
+
+    def tell_screens(self, paused):
+        try:
+            self.screens.sendto(b"pause on" if paused else b"pause off", SCREENS)
+        except OSError:
+            pass  # the desktop isn't running
+
+    def pause(self, reason, now):
+        if self.paused:
+            return
+        self.paused, self.reason, self.since = True, reason, time.time()
+        self.ends_with_game = self.game and self.settings["auto"]
+        self.resume_at = None
+        self.log(f"Frametop paused ({reason}{', until the game ends' if self.ends_with_game else ''})")
+        self.sound(True)
+        self.tell_screens(True)  # at once, even when the desktop is closing: that takes a while
+        self.on_change(True)
+        self.worker.submit(self.worker.pause, self.settings["desktop"])
+        self.save()
+
+    def resume(self, reason, now):
+        if not self.paused:
+            return
+        self.paused, self.resume_at, self.ends_with_game = False, None, False
+        self.log(f"Frametop resumed ({reason})")
+        self.sound(False)
+        self.tell_screens(False)
+        self.on_change(False)
+        self.worker.submit(self.worker.resume)
+        self.save()
+
+    def toggle(self, reason, now):
+        """Pausing only happens by itself as a game starts, so a game resumed during stays on."""
+        (self.resume if self.paused else self.pause)(reason, now)
+
+    def set(self, on, reason, now):
+        if on != self.paused:
+            self.toggle(reason, now)
+
+    # --- VR games ---
+    def game_state(self, running, now):
+        """From the pointer helper: a VR game runs or not (on a change and every 5 s)."""
+        self.game_seen = now
+        if running == self.game:
+            return
+        self.game = running
+        self.log(f"a VR game {'started' if running else 'ended'}")
+        if running:
+            self.resume_at = None  # the next game came before the resume
+            if self.settings["auto"]:
+                self.pause("game", now)
+        elif self.paused and self.ends_with_game:
+            self.resume_at = now + RESUME_DELAY
+
+    def tick(self, now):
+        if self.game and now - self.game_seen > GAME_STALE:
+            self.game_state(False, now)  # the helper went quiet: SteamVR (or the helper) stopped
+        if self.resume_at is not None and now >= self.resume_at:
+            self.resume("the game ended", now)
+
+    def timeout(self, now):
+        """How long the relay may wait before tick() has something to do."""
+        if self.resume_at is not None:
+            return max(0.05, self.resume_at - now)
+        return 1.0 if self.game else 3600.0
+
+    def helper_started(self):
+        """The pointer helper (re)started, so SteamVR did too, maybe with the gaze service."""
+        if self.paused:
+            self.worker.submit(self.worker.enforce)
+
+    def status(self):
+        return {"t": "pause", "paused": self.paused, "reason": self.reason, "since": self.since,
+                "ends_with_game": self.ends_with_game, "game": self.game,
+                "busy": self.worker.busy, "stopped": self.worker.snapshot(),
+                "gesture_reader": self.watch.connected, "auto": self.settings["auto"],
+                "desktop": self.settings["desktop"]}

input/input-relay.py

@@ -32,7 +32,8 @@ keyboard_toggle = open or close Frametop's keyboard, float_toggle = float the de
 pointer (else the active one) in VR, or put it back if it floats, dock_all = put every floating
 window back (both to ft-floatd, @frametop_float), profile:NAME = switch to that profile (ft-layout
 use NAME: its screens and apps; docs/profiles.md), steam_menu = open the SteamVR dashboard on
-Steam's menu, or close the dashboard (steam/ft-steam menu, through Steam's UI), command:CMD = run
+Steam's menu, or close the dashboard (steam/ft-steam menu, through Steam's UI), pause_toggle =
+pause Frametop for a VR game, or resume it (game_pause.py), command:CMD = run
 CMD with sh -c (on the host, as this service: its environment, output to its log, and
 COMMAND_PATH, so ft-layout, ft-float and ft-steam need no path), key = pass through as a key, none).
 
@@ -45,8 +46,8 @@ A modifier on its own ("125": Meta) is a tap: pressed and released with no other
 button, or scroll in between; the desktop gets an F24 press before its release, so Plasma's
 launcher doesn't open on a Meta tap that's bound. A rules file without "key_bindings" gets
 DEFAULT_KEY_BINDINGS (Meta tap: steam_menu, Meta+J: gaze_left, Meta+K: gaze_right, Meta+Shift+F:
-float_toggle); one with its own, even an empty one, doesn't. The float, profile, Steam menu and
+float_toggle); one with its own, even an empty one, doesn't. The float, profile, Steam menu,
-command actions work without pointer mode too. A combination with Meta also sends the desktop an
+pause and command actions work without pointer mode too. A combination with Meta also sends the desktop an
 F24 press and Meta's release right away: so letting go of Meta doesn't open Plasma's launcher, and
 a gaze click isn't Meta+click (KWin's window move and resize). Another key while Meta is still
 held gives the desktop Meta back. While typing goes to Steam, keyboards aren't grabbed, so Steam
@@ -92,6 +93,12 @@ keyboards) get their volume entries remapped to unused stand-in codes, so their
 other keys keep working for SteamVR; a device without a keymap that has only volume
 keys (the headset's pmic_resin) is grabbed. The keymaps go back when the relay exits.
 
+Frametop can pause for VR games (game_pause.py: by hand, with a controller gesture, or by itself
+while a game runs). Paused, it stops the services that cost the game CPU and GPU, and the relay
+plays a plain one: the pointer devices feed the virtual mouse and keyboard as without pointer
+mode, typing goes to Steam, and mapped buttons and key combinations do only pause_toggle,
+steam_menu and command:CMD (game_pause.PAUSED_ACTIONS).
+
 Pointer mode (POINTER=1 in ~/.config/frametop.conf) sends pointer devices to
 the ft-pointer helper (pointer/helper), which drives the ft_pointer
 SteamVR driver. With POINTER=0, pointer devices go to the virtual mouse and
@@ -104,7 +111,10 @@ Control socket (abstract datagram @frametop_relay, JSON replies to the sender):
   vrcapture <s>     take every controller button for s seconds (0: stop), so the settings
                     app can capture one; watchers see them as events with id frame_controller
   vrbtn, vrhello, gazeawake   from the pointer helper (above)
+  vrgame 1|0        from the pointer helper: a VR game runs (on a change and every 5 s), for pausing
   textfield 1|0     from the desktop's input method (above)
+  pause on|off|toggle [reason]   pause Frametop or resume it (input/ft-pause; the gesture reader)
+  pause ?           the pause state, as {"t": "pause", ...}
 
 Runs on the Frame host as a user service (frametop-input-relay.service). The
 virtual devices are parked in systemd's file descriptor store, so a relay
@@ -130,6 +140,8 @@ import subprocess
 import sys
 import time
 
+import game_pause
+
 # Linux input constants (include/uapi/linux/input-event-codes.h, input.h, uinput.h).
 EV_SYN, EV_KEY, EV_REL, EV_MSC = 0x00, 0x01, 0x02, 0x04
 SYN_REPORT = 0
@@ -196,7 +208,7 @@ RULES_PATH = os.path.expanduser("~/.config/frametop-input.json")
 ACTIONS = ("left", "right", "middle", "back", "scroll_up", "scroll_down", "dashboard", "recenter",
            "pointer_toggle", "follow_toggle", "gaze_toggle", "gaze_precision", "gaze_drag", "gaze_left", "gaze_right",
            "gaze_quickcal", "sens_up", "sens_down", "layout_reset", "screens_toggle", "keyboard_toggle", "float_toggle",
-           "dock_all", "steam_menu", "key", "none")
+           "dock_all", "steam_menu", "pause_toggle", "key", "none")
 # Gaze mode is a mouse feature: these never come from a controller button (docs/gaze-controllers.md).
 GAZE_ACTIONS = ("gaze_toggle", "gaze_precision", "gaze_drag", "gaze_left", "gaze_right", "gaze_quickcal")
 # Key combinations a rules file without "key_bindings" gets: a Meta tap opens Steam's menu, Meta+J
@@ -229,7 +241,17 @@ def known_action(a):
 
 
 def needs_pointer(a):
-    return a not in FLOAT_ACTIONS and a != "steam_menu" and not a.startswith((PROFILE, COMMAND))
+    return a not in FLOAT_ACTIONS and a not in ("steam_menu", "pause_toggle") and not a.startswith((PROFILE, COMMAND))
+
+
+def works_paused(a):
+    """An action that still does something while Frametop is paused (game_pause.py)."""
+    return a in game_pause.PAUSED_ACTIONS or a.startswith(COMMAND)
+
+
+# What pressed pause_toggle, for the log (do_action's source).
+PAUSE_SOURCES = {"mouse": "mouse button", "keyboard": "key combination", "left": "controller button",
+                 "right": "controller button"}
 KEYS = "\0frametop_keys"  # keys of keyboards grabbed for the desktop, for other readers
 REPO = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 FT_LAYOUT = os.path.join(REPO, "layout", "ft-layout")
@@ -605,6 +627,22 @@ class Pointer:
         pending = (self.scroll_until, self.claim_at, self.claim_release, self.system_at, self.system_release)
         return 0.02 if any(t is not None for t in pending) else 0.5
 
+    def stand_down(self):
+        """Frametop is pausing: a pulse under way ends now, and the pointer lets go."""
+        if self.system_release is not None:
+            self.send("btn system 0")
+        if self.claim_release is not None:
+            self.send("btn a 0")
+        if self.scroll_until is not None:
+            self.send("scroll 0 0")
+        self.system_at = self.system_release = self.claim_at = self.claim_release = self.scroll_until = None
+        self.dx = self.dy = self.pending = 0
+        self.gaze_awake_until = 0.0
+        if self.active:
+            self.send("hide")
+            self.active = False
+            log("pointer off (paused)")
+
 
 class Node:
     """One input event node: a candidate device (mouse or keyboard, USB or Bluetooth),
@@ -688,23 +726,42 @@ def main():
     # desktop_until: typing goes to the Frametop desktop until then (ft-screens says so
     # every second); typing_applied: the grabs match that as of the last apply_roles().
     # vr_capture_until: every controller button is taken until then (the settings app capturing one).
-    state = {"pointer": None, "rules": {}, "share_keys": False,
+    # pointer: the 3D mouse while it's in use, pointer_conf: the one the config asks for (they
+    # differ while Frametop is paused).
+    state = {"pointer": None, "pointer_conf": None, "rules": {}, "share_keys": False,
              "desktop_until": 0.0, "typing_applied": None, "vr_capture_until": 0.0}
 
+    def pause_changed(paused):
+        """Frametop paused or resumed (game_pause.py): the relay's own part."""
+        p = state["pointer_conf"]
+        if paused:
+            if p:
+                p.stand_down()
+            state["pointer"] = None
+            state["desktop_until"] = 0.0  # typing goes to Steam
+        else:
+            state["pointer"] = p
+        apply_roles()
+        vr_bind(time.monotonic())
+
+    pause = game_pause.GamePause(log, pause_changed, VR_BUTTONS)
+
     def load_config():
         conf = read_config()
         state["rules"] = read_rules()
         state["share_keys"] = conf.get("SHARE_KEYS", "0") == "1"
         if conf.get("POINTER", "0") == "1":
-            p = state["pointer"] or Pointer(0.03, 30)
+            p = state["pointer_conf"] or Pointer(0.03, 30)
             p.sensitivity = float(conf.get("POINTER_SENSITIVITY", "0.03"))
             p.idle = float(conf.get("POINTER_IDLE", "30"))
             p.wake_counts = int(conf.get("POINTER_WAKE_COUNTS", "40"))
-            state["pointer"] = p
+            state["pointer_conf"] = p
             log(f"pointer mode: {p.sensitivity} deg/count, idle {p.idle} s, wake {p.wake_counts} counts")
         else:
-            state["pointer"] = None
+            state["pointer_conf"] = None
             log("pointer mode off: pointer devices feed the virtual mouse and keyboard")
+        state["pointer"] = None if pause.paused else state["pointer_conf"]
+        pause.configure(state["rules"])
 
     load_config()
     tap = None  # the modifier (folded, MODIFIERS) pressed alone, with nothing since: its release is a tap
@@ -719,7 +776,7 @@ def main():
             state["vr_capture_until"] = 0.0
             buttons = " ".join(b for b, a in state["rules"]["controller_buttons"].items()
                                if b in VR_BUTTONS and known_action(a) and a not in ("key", "none")
-                               and a not in GAZE_ACTIONS) or "-"
+                               and a not in GAZE_ACTIONS and (not pause.paused or works_paused(a))) or "-"
             if state["rules"].get("controller_in_games"):
                 buttons = "+games " + buttons
         try:
@@ -764,6 +821,12 @@ def main():
     def do_action(action, value, now, source="mouse"):
         """A mapped mouse or controller button, or key combination (pointer mode only, but
         for the actions needs_pointer() says don't)."""
+        if action == "pause_toggle":
+            if value == 1:
+                pause.toggle(PAUSE_SOURCES.get(source, source), now)
+            return
+        if pause.paused and not works_paused(action):
+            return
         if action == "keyboard_toggle":
             if value == 1 and vr_keyboard_mode() != "never":
                 vr_keyboard("toggle")
@@ -832,7 +895,7 @@ def main():
             return value == 2 and code in combos_down
         combo = "+".join(str(c) for c in sorted(held_modifiers) + [code])
         action = state["rules"]["key_bindings"].get(combo)
-        if not known_action(action) or action in ("key", "none"):
+        if not known_action(action) or action in ("key", "none") or (pause.paused and not works_paused(action)):
             return False
         combos_down[code] = action
         if held_meta - meta_hidden:
@@ -853,7 +916,7 @@ def main():
     def modifier_tap(mod, now):
         """A modifier pressed and released alone: its binding, if it has one ("125": Meta tap)."""
         action = state["rules"]["key_bindings"].get(str(mod))
-        if not known_action(action) or action in ("key", "none"):
+        if not known_action(action) or action in ("key", "none") or (pause.paused and not works_paused(action)):
             return
         # The desktop gets a key in between before the release goes there, so the tap isn't one
         # there too: a Meta tap would open Plasma's launcher.
@@ -1054,7 +1117,7 @@ def main():
             try:
                 if cmd == "keyboard":
                     # From ft-screens (unbound, no reply): where typing goes, repeated every second.
-                    desktop = len(words) > 1 and words[1] == "desktop"
+                    desktop = len(words) > 1 and words[1] == "desktop" and not pause.paused
                     state["desktop_until"] = now + 3.0 if desktop else 0.0
                     continue
                 if cmd == "vrbtn" and len(words) == 3 and words[1] in VR_BUTTONS and words[2] in ("0", "1"):
@@ -1062,6 +1125,20 @@ def main():
                     continue
                 if cmd == "vrhello":
                     vr_bind(now)
+                    pause.helper_started()
+                    continue
+                if cmd == "vrgame" and len(words) == 2:
+                    pause.game_state(words[1] == "1", now)
+                    continue
+                if cmd == "pause" and len(words) >= 2 and words[1] in ("on", "off", "toggle", "?"):
+                    # From input/ft-pause, the settings app, or the gesture reader (unbound, no reply).
+                    reason = words[2] if len(words) > 2 else "command"
+                    if words[1] == "toggle":
+                        pause.toggle(reason, now)
+                    elif words[1] != "?":
+                        pause.set(words[1] == "on", reason, now)
+                    if addr:
+                        reply(addr, pause.status())
                     continue
                 if cmd == "textfield" and len(words) == 2:
                     text_field(words[1] == "1")
@@ -1073,7 +1150,8 @@ def main():
                 if not addr:
                     continue  # unbound sender, nowhere to reply
                 if cmd == "devices":
-                    reply(addr, {"t": "devices", "pointer_mode": state["pointer"] is not None,
+                    reply(addr, {"t": "devices", "pointer_mode": state["pointer_conf"] is not None,
+                                 "paused": pause.paused,
                                  "actions": ACTIONS,
                                  "nodes": [n.describe() for n in nodes.values() if n.candidate]})
                 elif cmd == "watch":
@@ -1156,16 +1234,18 @@ def main():
                 apply_roles()
 
         ready, _, _ = select.select(list(nodes) + [control], [], [],
-                                    volume.timeout(now, pointer.timeout() if pointer else 0.5))
+                                    min(volume.timeout(now, pointer.timeout() if pointer else 0.5), pause.timeout(now)))
         now = time.monotonic()
         if pointer:
             pointer.tick(now)
         volume.tick(now)
+        pause.tick(now)
         if state["vr_capture_until"] and now >= state["vr_capture_until"]:
             vr_bind(now)  # capture over: back to the mapped buttons
         if (now < state["desktop_until"]) != state["typing_applied"] or waiting:
             waiting = apply_roles()
         for fd in ready:
+            pointer = state["pointer"]  # (a pause or resume in this batch changes it)
             if fd is control:
                 handle_control(now)
                 continue
@@ -1220,7 +1300,7 @@ def main():
                     continue
                 if etype == EV_KEY:
                     action = buttons.get(str(code), DEFAULT_BUTTONS.get(code, "key"))
-                    if pointer and action not in ("key", "none"):
+                    if (pointer or action == "pause_toggle") and action not in ("key", "none"):
                         do_action(action, value, now)
                         continue
                     if action == "none":

input/test/keys-test.py

@@ -3,8 +3,9 @@
 
 Runs the relay's main() against a fake pass-through keyboard and a fake mouse (pipes), with
 every socket it sends to renamed, no uinput devices, no grabs, and ft-steam swapped for a
-logger. Nothing reaches the live desktop, SteamVR, or the running relay, so it's safe next
+logger. Pausing (game_pause.py) is a stub: no threads, state file, or services. Nothing reaches
-to them. Rules come from the test, not ~/.config/frametop-input.json.
+the live desktop, SteamVR, or the running relay, so it's safe next to them. Rules come from the
+test, not ~/.config/frametop-input.json.
 
   input/test/keys-test.py [RELAY]   (default: input/input-relay.py next to this folder)
 """
@@ -26,8 +27,41 @@ with open(relay_path) as f:
     src = f.read().replace('"\\0frametop_relay"', f'"\\0{tag}_relay"')
 relay = importlib.util.module_from_spec(importlib.util.spec_from_loader("relay", loader=None))
 relay.__file__ = os.path.abspath(relay_path)
+sys.path.insert(0, os.path.dirname(os.path.abspath(relay_path)))  # its game_pause and vrws
 exec(compile(src, relay_path, "exec"), relay.__dict__)
 
+
+class StubPause:
+    """game_pause.GamePause without its threads, state file, or services."""
+    paused = False
+
+    def __init__(self, log, on_change, buttons):
+        self.on_change = on_change
+        stub["pause"] = self
+
+    def toggle(self, reason, now):
+        self.paused = not self.paused
+        self.on_change(self.paused)
+
+    def set(self, on, reason, now):
+        if on != self.paused:
+            self.toggle(reason, now)
+
+    def status(self):
+        return {"t": "pause", "paused": self.paused}
+
+    def timeout(self, now):
+        return 3600.0
+
+    def configure(self, *args):
+        pass
+
+    game_state = tick = helper_started = configure
+
+
+stub = {}
+relay.game_pause.GamePause = StubPause
+
 for name in ("SCREENS", "HELPER", "FLOAT", "GAZED", "KEYS"):
     setattr(relay, name, f"\0{tag}_{name.lower()}")
 OUT = tempfile.mkdtemp(prefix="ft-keys-test-")
@@ -80,6 +114,7 @@ fake_os = type(os)("os")
 fake_os.__dict__.update(os.__dict__)
 fake_os.listdir = lambda path: ["event900", "event901"] if path == "/dev/input" else os.listdir(path)
 fake_os.stat = lambda path, *a, **k: Inode() if path in FAKE else os.stat(path, *a, **k)
+fake_os.access = lambda path, mode, *a, **k: path in FAKE or os.access(path, mode, *a, **k)
 relay.os = fake_os
 
 
@@ -143,6 +178,15 @@ def use(key_bindings):
     typed()
 
 
+def pause(cmd):
+    c = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+    c.bind("")
+    c.settimeout(2)
+    c.sendto(f"pause {cmd} test".encode(), f"\0{tag}_relay")
+    c.recv(4096)
+    time.sleep(0.05)
+
+
 def lines(path, wait=0.3):
     time.sleep(wait)
     try:
@@ -162,7 +206,7 @@ def check(label, got, want):
         failures.append(label)
 
 
-META, RMETA, SHIFT, CTRL, RCTRL, A, F, J = 125, 126, 42, 29, 97, 30, 33, 36
+META, RMETA, SHIFT, CTRL, RCTRL, A, F, J, P = 125, 126, 42, 29, 97, 30, 33, 36, 25
 F24 = ["key 194 1", "key 194 0"]
 
 
@@ -206,9 +250,25 @@ def tests():
     check("right Ctrl tap runs its command, which finds Frametop's tools", lines(cmd_log), ["combo", "3"])
     check("Ctrl tap: F24 before Ctrl's release", typed(), ["key 97 1"] + F24 + ["key 97 0"])
 
+    use({"125+36": "gaze_left", "29": f"command:echo paused >> {cmd_log}", "42+125+25": "pause_toggle"})
+    pause("on")
+    check("pause on: paused", stub["pause"].paused, True)
+    key(META, 1); key(J, 1); key(J, 0); key(META, 0)
+    check("paused: Meta+J (gaze click) does nothing and is typed as is", typed(),
+          ["key 125 1", "key 36 1", "key 36 0", "key 125 0"])
+    key(RCTRL, 1); key(RCTRL, 0)
+    check("paused: a command still runs", lines(cmd_log), ["combo", "3", "paused"])
+    typed()
+    key(SHIFT, 1); key(META, 1); key(P, 1); key(P, 0); key(META, 0); key(SHIFT, 0)
+    check("paused: Meta+Shift+P (pause_toggle) resumes", stub["pause"].paused, False)
+    check("Meta+Shift+P isn't typed", [k for k in typed() if k.startswith("key 25 ")], [])
+    key(META, 1); key(J, 1); key(J, 0); key(META, 0)
+    check("resumed: Meta+J is a combination again", typed(), ["key 125 1"] + F24 + ["key 125 0"])
+
     check("an empty command isn't an action", relay.known_action("command:  "), False)
-    check("steam_menu and commands work without pointer mode",
+    check("steam_menu, pause_toggle and commands work without pointer mode",
-          (relay.needs_pointer("steam_menu"), relay.needs_pointer("command:ls")), (False, False))
+          (relay.needs_pointer("steam_menu"), relay.needs_pointer("pause_toggle"), relay.needs_pointer("command:ls")),
+          (False, False, False))
     print("FAILED: " + ", ".join(failures) if failures else "all passed", flush=True)
     shutil.rmtree(OUT, ignore_errors=True)
     os._exit(1 if failures else 0)

input/test/pause-test.py

@@ -0,0 +1,214 @@
+#!/usr/bin/env python3
+"""Offline test of pausing for VR games (input/game_pause.py): the controller gesture, and when
+Frametop pauses and resumes by itself. The worker (services, remote desktop, the desktop) and
+the controller reader are stubs, the state file is a temporary one, and ft-screens' socket is
+renamed, so nothing reaches the live Frametop, SteamVR, or the running relay.
+
+  input/test/pause-test.py
+"""
+import os
+import sys
+import tempfile
+
+sys.path.insert(0, os.path.join(os.path.dirname(os.path.abspath(__file__)), ".."))
+import game_pause as gp  # noqa: E402
+
+failures = []
+
+
+def check(label, got, want):
+    ok = got == want
+    print(("ok    " if ok else "FAIL  ") + label + ("" if ok else f": got {got!r}, want {want!r}"), flush=True)
+    if not ok:
+        failures.append(label)
+
+
+# ---------------------------------------------------------------- the gesture
+L, R = "left/thumbstick", "right/thumbstick"
+
+
+def presses(g, events):
+    """events: (time, button, down); how many times the gesture went off."""
+    return sum(g.feed(b, d, t) for t, b, d in events)
+
+
+def both(t, hold=0.1, gap=0.02):
+    """Both sticks clicked at t (the right one gap later), held for hold."""
+    return [(t, L, True), (t + gap, R, True), (t + hold, L, False), (t + hold + gap, R, False)]
+
+
+g = gp.Gesture((L, R), 2)
+check("both sticks twice: goes off", presses(g, both(0) + both(0.3)), 1)
+g = gp.Gesture((L, R), 2)
+check("both sticks once: nothing", presses(g, both(0)), 0)
+g = gp.Gesture((L, R), 2)
+check("both sticks twice, 0.9 s apart: nothing", presses(g, both(0) + both(0.9)), 0)
+g = gp.Gesture((L, R), 2)
+check("left held (sprint), right clicked twice: nothing",
+      presses(g, [(0, L, True), (1.0, R, True), (1.1, R, False), (1.3, R, True), (1.4, R, False)]), 0)
+g = gp.Gesture((L, R), 2)
+check("sticks 0.5 s apart, twice: nothing", presses(g, both(0, gap=0.5, hold=0.6) + both(1.2, gap=0.5, hold=0.6)), 0)
+g = gp.Gesture((L, R), 2)
+check("three double presses in a row: once", presses(g, both(0) + both(0.3) + both(0.6)), 1)
+g = gp.Gesture((L, R), 2)
+check("again after a second: twice in all", presses(g, both(0) + both(0.3) + both(2.0) + both(2.3)), 2)
+g = gp.Gesture((L, R), 2)
+check("repeated down states count once",
+      presses(g, [(0, L, True), (0.01, L, True), (0.02, R, True), (0.03, R, True), (0.1, L, False), (0.1, R, False)]
+              + both(0.3)), 1)
+g = gp.Gesture((L, R), 1)
+check("both sticks once (presses 1): goes off", presses(g, both(0)), 1)
+g = gp.Gesture(("right/b",), 2)
+check("one button double-clicked: goes off",
+      presses(g, [(0, "right/b", True), (0.1, "right/b", False), (0.3, "right/b", True)]), 1)
+g = gp.Gesture(("right/b",), 2)
+check("other buttons don't count", presses(g, [(0, "right/a", True), (0.2, "right/a", True)]), 0)
+
+VR = ("left/thumbstick", "right/thumbstick", "right/b", "right/a")
+check("no pause_gesture: both sticks twice", gp.gesture_of({}, VR), ((L, R), 2))
+check("pause_gesture null: none", gp.gesture_of({"pause_gesture": None}, VR), None)
+check("one button, presses 1: still twice", gp.gesture_of({"pause_gesture": {"buttons": ["right/b"], "presses": 1}}, VR),
+      (("right/b",), 2))
+check("unknown buttons dropped", gp.gesture_of({"pause_gesture": {"buttons": ["right/zz", "right/a"]}}, VR),
+      (("right/a",), 2))
+check("settings: defaults", gp.settings_of({}, VR)["auto"], True)
+check("settings: unknown desktop mode is hide", gp.settings_of({"pause_desktop": "x"}, VR)["desktop"], "hide")
+
+
+# ---------------------------------------------------------------- pausing by itself
+class StubWorker:
+    def __init__(self, log, save):
+        self.jobs = []
+        self.busy = False
+
+    def start(self):
+        pass
+
+    def submit(self, job, *args):
+        self.jobs.append(job.__name__)
+
+    def snapshot(self):
+        return {"units": [], "remote": False, "desktop": None}
+
+    def restore(self, stopped):
+        self.restored = stopped
+
+    def pause(self, desktop):
+        pass
+
+    def resume(self):
+        pass
+
+    def enforce(self):
+        pass
+
+
+class StubWatch:
+    connected = False
+
+    def __init__(self, log):
+        pass
+
+    def start(self):
+        pass
+
+    def set_gesture(self, spec):
+        self.spec = spec
+
+
+tmp = tempfile.mkdtemp(prefix="ft-pause-test-")
+gp.STATE_PATH = os.path.join(tmp, "pause.json")
+gp.SCREENS = f"\0ft_pause_test_{os.getpid()}_screens"
+gp.Worker, gp.ControllerWatch = StubWorker, StubWatch
+changes = []
+
+
+def new(rules=None):
+    """A relay starting afresh: not paused before."""
+    if os.path.exists(gp.STATE_PATH):
+        os.remove(gp.STATE_PATH)
+    changes.clear()
+    p = gp.GamePause(lambda *a: None, changes.append, VR)
+    p.configure(dict({"pause_sound": False}, **(rules or {})))
+    return p
+
+
+p = new()
+p.game_state(True, 0)
+check("a game starts: paused", (p.paused, p.reason, p.ends_with_game), (True, "game", True))
+check("the relay heard", changes, [True])
+p.game_state(True, 5)
+p.tick(5)
+check("the helper repeats it: still paused, nothing new", (p.paused, changes), (True, [True]))
+p.game_state(False, 10)
+p.tick(12)
+check("the game ends: not yet resumed", p.paused, True)
+p.tick(15.1)
+check("5 s later: resumed", (p.paused, changes), (False, [True, False]))
+check("the worker paused and resumed", p.worker.jobs, ["pause", "resume"])
+
+p = new()
+p.game_state(True, 0)
+p.game_state(False, 10)
+p.game_state(True, 12)
+p.tick(16)
+check("the next game starts within 5 s: stays paused", p.paused, True)
+p.game_state(False, 20)
+p.tick(25.1)
+check("and resumes 5 s after that one ends", p.paused, False)
+
+p = new()
+p.game_state(True, 0)
+p.toggle("gesture", 1)
+check("resumed during a game: running", p.paused, False)
+p.game_state(True, 6)
+p.tick(30)
+check("and stays running while that game runs", p.paused, False)
+p.game_state(False, 40)
+p.game_state(True, 50)
+check("the next game pauses again", p.paused, True)
+
+p = new()
+p.toggle("command", 0)
+check("paused outside a game: not tied to one", (p.paused, p.ends_with_game), (True, False))
+p.game_state(True, 1)
+p.game_state(False, 10)
+p.tick(20)
+check("a game comes and goes: still paused", p.paused, True)
+p.toggle("command", 21)
+check("toggled: running", p.paused, False)
+
+p = new({"pause_auto": False})
+p.game_state(True, 0)
+check("auto off: a game doesn't pause", p.paused, False)
+p.toggle("gesture", 1)
+p.game_state(False, 10)
+p.tick(20)
+check("auto off: a pause during a game outlasts it", p.paused, True)
+
+p = new()
+p.game_state(True, 0)
+p.tick(0 + gp.GAME_STALE + 0.1)
+check("the helper goes quiet: the game counts as ended", p.game, False)
+p.tick(0 + gp.GAME_STALE + gp.RESUME_DELAY + 0.2)
+check("and the pause ends", p.paused, False)
+
+p = new()
+p.toggle("gesture", 0)
+q = gp.GamePause(lambda *a: None, changes.append, VR)
+check("a relay restarted while paused stays paused", (q.paused, q.reason), (True, "gesture"))
+check("and stops the services again", q.worker.jobs, ["enforce"])
+q.toggle("gesture", 1)
+r = gp.GamePause(lambda *a: None, changes.append, VR)
+check("resumed: the next relay starts running", r.paused, False)
+
+p = new({"pause_gesture": None})
+check("pause_gesture null: the reader gets none", p.watch.spec, None)
+check("status", sorted(p.status()), sorted(["t", "paused", "reason", "since", "ends_with_game", "game", "busy",
+                                            "stopped", "gesture_reader", "auto", "desktop"]))
+
+print("FAILED: " + ", ".join(failures) if failures else "all passed", flush=True)
+for f in os.listdir(tmp):
+    os.remove(os.path.join(tmp, f))
+os.rmdir(tmp)
+sys.exit(1 if failures else 0)

input/vrws.py

@@ -0,0 +1,198 @@
+#!/usr/bin/python3
+"""vrws: vrserver's local web socket, with nothing but the standard library.
+
+vrserver (SteamVR) serves its controller binding page on 127.0.0.1:27062, and that page
+follows the controllers' raw input through a web socket there (mailbox input_server,
+request_input_state_updates). Reading it takes nothing from anyone: whatever the buttons are
+bound to still happens, and it works whatever app has input focus, VR games included. SteamVR
+input only reaches the focused app, or an overlay with global input, which then takes the button
+from the game (pointer/helper/vrbuttons.h). frame-voice reads its push-to-talk button the same
+way. It's undocumented, so a SteamVR update could change it (scripts/update-check.py checks it).
+The host's Python has no `websockets` module, so this is a small RFC 6455 client of its own.
+
+  controllers()   the Frame controllers SteamVR has now: {root path: "left" | "right"}. A
+                  controller's root path is /user/hand/<side>, or /devices/cv/<serial> while the
+                  3D mouse's virtual controller holds that hand role.
+  VrSocket()      a connection: open(mailbox), subscribe(path), messages(timeout) -> raw texts,
+                  each a JSON object like {"type": "update_component_states", "device": path,
+                  "components": {"/input/thumbstick/click": true, ...}} with the components
+                  that changed (mostly capacitive sensing, about 160 a second)
+
+Run as a program, it prints the controllers' button changes for a while (default 10 s):
+
+  input/vrws.py [seconds]
+"""
+import base64
+import json
+import os
+import select
+import socket
+import struct
+import sys
+import time
+import urllib.request
+
+HOST, PORT = "127.0.0.1", 27062
+ORIGIN = f"http://{HOST}:{PORT}"
+# vrserver answers the binding page's own requests; these headers make ours look like them.
+HEADERS = {"Referer": f"{ORIGIN}/dashboard/controllerbinding.html"}
+
+
+def getstate(timeout=3):
+    """vrserver's /input/getstate.json: the devices and their input components."""
+    req = urllib.request.Request(f"{ORIGIN}/input/getstate.json", headers=HEADERS)
+    with urllib.request.urlopen(req, timeout=timeout) as resp:
+        return json.load(resp)
+
+
+def controllers(timeout=3):
+    """{root path: side} for the Frame controllers SteamVR has now."""
+    return {d["root_path"]: d["side"] for d in getstate(timeout).get("devices", [])
+            if d.get("controller_type") == "frame_controller" and d.get("root_path")
+            and d.get("side") in ("left", "right")}
+
+
+class VrSocket:
+    def __init__(self, timeout=3):
+        self.sock = socket.create_connection((HOST, PORT), timeout=timeout)
+        try:
+            key = base64.b64encode(os.urandom(16)).decode()
+            self.sock.sendall((f"GET / HTTP/1.1\r\nHost: {HOST}:{PORT}\r\nUpgrade: websocket\r\n"
+                               f"Connection: Upgrade\r\nSec-WebSocket-Key: {key}\r\nSec-WebSocket-Version: 13\r\n"
+                               f"Origin: {ORIGIN}\r\nReferer: {HEADERS['Referer']}\r\n\r\n").encode())
+            head = b""
+            while b"\r\n\r\n" not in head:
+                chunk = self.sock.recv(4096)
+                if not chunk:
+                    raise OSError("vrserver closed the connection during the handshake")
+                head += chunk
+            head, rest = head.split(b"\r\n\r\n", 1)
+            status = head.split(b"\r\n", 1)[0]
+            if b" 101 " not in status + b" ":
+                raise OSError(f"vrserver refused the web socket: {status.decode(errors='replace')}")
+        except BaseException:
+            self.sock.close()
+            raise
+        self.sock.settimeout(None)
+        self.buf = bytearray(rest)
+        self.parts = bytearray()  # a fragmented message so far
+        self.mailbox = ""
+
+    def fileno(self):
+        return self.sock.fileno()
+
+    def close(self):
+        try:
+            self._frame(0x8, b"")
+        except OSError:
+            pass
+        self.sock.close()
+
+    def _frame(self, opcode, payload):
+        """One frame to vrserver: final, masked (as a client's must be)."""
+        n = len(payload)
+        head = bytes([0x80 | opcode])
+        if n < 126:
+            head += bytes([0x80 | n])
+        elif n < 65536:
+            head += bytes([0x80 | 126]) + struct.pack(">H", n)
+        else:
+            head += bytes([0x80 | 127]) + struct.pack(">Q", n)
+        mask = os.urandom(4)
+        self.sock.sendall(head + mask + bytes(b ^ mask[i % 4] for i, b in enumerate(payload)))
+
+    def send(self, text):
+        self._frame(0x1, text.encode())
+
+    def open(self, mailbox):
+        self.send(f"mailbox_open {mailbox}")
+        self.mailbox = mailbox
+
+    def subscribe(self, path, on=True):
+        kind = "request_input_state_updates" if on else "cancel_input_state_updates"
+        self.send("mailbox_send input_server " +
+                  json.dumps({"type": kind, "device_path": path, "returnAddress": self.mailbox}))
+
+    def messages(self, timeout=None):
+        """The text messages that came in, as strings: waits up to `timeout` seconds (None:
+        forever) for some, [] at the timeout. Raises OSError when the connection ends."""
+        out = self._parse()
+        if out:
+            return out
+        if not select.select([self.sock], [], [], timeout)[0]:
+            return []
+        chunk = self.sock.recv(65536)
+        if not chunk:
+            raise OSError("vrserver closed the web socket")
+        self.buf += chunk
+        return self._parse()
+
+    def _parse(self):
+        """Every whole frame in the buffer; a partial one waits for the rest."""
+        out, buf, pos = [], self.buf, 0
+        while len(buf) - pos >= 2:
+            b0, b1 = buf[pos], buf[pos + 1]
+            n, head = b1 & 0x7F, 2
+            if n == 126:
+                if len(buf) - pos < 4:
+                    break
+                n, head = struct.unpack_from(">H", buf, pos + 2)[0], 4
+            elif n == 127:
+                if len(buf) - pos < 10:
+                    break
+                n, head = struct.unpack_from(">Q", buf, pos + 2)[0], 10
+            masked = b1 & 0x80
+            if masked:
+                head += 4
+            if len(buf) - pos < head + n:
+                break
+            data = bytes(buf[pos + head:pos + head + n])
+            if masked:  # servers don't mask, but nothing says they can't
+                mask = buf[pos + head - 4:pos + head]
+                data = bytes(b ^ mask[i % 4] for i, b in enumerate(data))
+            pos += head + n
+            opcode = b0 & 0x0F
+            if opcode == 0x8:
+                raise OSError("vrserver closed the web socket")
+            if opcode == 0x9:
+                self._frame(0xA, data)  # ping: pong
+            elif opcode in (0x0, 0x1, 0x2):
+                self.parts += data
+                if b0 & 0x80:
+                    out.append(self.parts.decode(errors="replace"))
+                    self.parts = bytearray()
+        del buf[:pos]
+        return out
+
+
+def main():
+    seconds = float(sys.argv[1]) if len(sys.argv) > 1 else 10.0
+    ws = VrSocket()
+    ws.open(f"frametop_vrws_{os.getpid()}")
+    sides = controllers()
+    for path, side in sides.items():
+        print(f"{side} controller: {path}", flush=True)
+        ws.subscribe(path)
+    if not sides:
+        print("no Frame controllers", flush=True)
+    start = time.monotonic()
+    count = 0
+    try:
+        while time.monotonic() - start < seconds:
+            for text in ws.messages(timeout=0.5):
+                count += 1
+                if "/click" not in text:
+                    continue
+                msg = json.loads(text)
+                side = sides.get(msg.get("device"), msg.get("device"))
+                for name, value in sorted(msg.get("components", {}).items()):
+                    if name.endswith("/click"):
+                        print(f"{time.monotonic() - start:7.3f}  {side} {name[len('/input/'):-len('/click')]} "
+                              f"{'down' if value else 'up'}", flush=True)
+    finally:
+        ws.close()
+    print(f"{count} messages in {seconds:.0f} s")
+
+
+if __name__ == "__main__":
+    main()

pointer/helper/ft-pointer.cpp

@@ -267,7 +267,8 @@
 //
 // Commands (datagrams on @ft_pointer_helper): show, hide, recenter, move <dyaw> <dpitch>,
 // follow on|off|toggle (head follow, until the next restart or a change to POINTER_FOLLOW),
-// gaze on|off|toggle|? (gaze mode, likewise with POINTER_GAZE; ? only asks), gz ... (the gaze, from ft-gazed),
+// gaze on|off|toggle|? (gaze mode, likewise with POINTER_GAZE; ? only asks, and "? headset" adds
+// worn|away to the reply), gz ... (the gaze, from ft-gazed),
 // reload (re-read the settings below), debug (toggle a twice-a-second state log),
 // overlays (replies with the overlay list as JSON, see OverlayList),
 // vrbind/vrglobal/vrstatus (Frame controller buttons, see vrbuttons.h),
@@ -931,8 +932,8 @@ int main() {
     Clock::time_point handUsed{};  // a gesture began then (keeps the pointer, like gaze mode)
     Clock::time_point lastTyping{};  // the relay's last "typing": a key on a keyboard
     // Gaze mode outside games, and its dot (see the top): lastMove/lastHeld/pulseAt.
-    bool inGame = false, gazeAwake = false;
+    bool inGame = false, gazeAwake = false, gameSent = false;
-    Clock::time_point inGameAt{}, gazeAwakeAt{};
+    Clock::time_point inGameAt{}, gazeAwakeAt{}, gameSentAt{};
     Clock::time_point lastMove{}, lastHeld{}, pulseAt{};
     // The left button, as sent to the driver; pressRight: the next press is the right button
     // instead (gaze_right), heldButton: the one pressed.
@@ -1283,6 +1284,13 @@ int main() {
                 gazeAwakeAt = t;
                 SendTo(out, "frametop_relay", awake ? "gazeawake 1" : "gazeawake 0");
             }
+            // The relay pauses Frametop for VR games (input/game_pause.py). Repeated, so a relay
+            // that restarts learns it, and silence (SteamVR gone) ends the game there.
+            if (inGame != gameSent || t - gameSentAt > std::chrono::seconds(5)) {
+                gameSent = inGame;
+                gameSentAt = t;
+                SendTo(out, "frametop_relay", inGame ? "vrgame 1" : "vrgame 0");
+            }
         }
 
         // Commands from the relay.
@@ -1380,7 +1388,12 @@ int main() {
                     std::printf("gaze mode %s\n", gazeOn ? "on" : "off");
                     std::fflush(stdout);
                 }
-                reply(gazeOn ? "ok on" : "ok off");
+                // "gaze ? headset" (the gaze service, which idles while nobody wears the headset)
+                // also says whether someone does.
+                if (std::strstr(arg, "headset"))
+                    reply(gazeOn ? (headsetOff ? "ok on away" : "ok on worn") : (headsetOff ? "ok off away" : "ok off worn"));
+                else
+                    reply(gazeOn ? "ok on" : "ok off");
                 continue;
             }
             const bool mouseInput = std::strncmp(buf, "move", 4) == 0 || std::strncmp(buf, "btn", 3) == 0 ||

screens/compositor.c

@@ -381,7 +381,10 @@ static void keys_update(struct server *s) {
            offsetof(struct sockaddr_un, sun_path) + 1 + sizeof name - 1);
 }
 
-// Every ~11 ms (90 Hz): SteamVR events, and frame callbacks for screens that committed.
+// Every ~11 ms (90 Hz): SteamVR events, and frame callbacks for screens that committed. While
+// Frametop is paused for a VR game (everything hidden), every 100 ms, and the frame callbacks
+// once a second: KWin draws a screen only after its callback, and its apps wait for theirs, so
+// the desktop hardly draws until it's resumed.
 static int tick(void *data) {
     struct server *s = data;
     ft_vr_poll(handle_vr_event, s);
@@ -395,14 +398,15 @@ static int tick(void *data) {
     }
     struct timespec now;
     clock_gettime(CLOCK_MONOTONIC, &now);
-    for (int i = 0; i < MAX_SCREENS; ++i) {
+    const bool paused = ft_vr_paused();
+    for (int i = 0; i < MAX_SCREENS && (!paused || s->ticks % 10 == 0); ++i) {
         struct screen *sc = s->screens[i];
         if (sc && sc->frame_pending) {
             sc->frame_pending = false;
             wlr_surface_send_frame_done(sc->toplevel->base->surface, &now);
         }
     }
-    wl_event_source_timer_update(s->tick, 11);
+    wl_event_source_timer_update(s->tick, paused ? 100 : 11);
     return 0;
 }
 

screens/handcut.cpp

@@ -279,9 +279,6 @@ PFNEGLCREATEIMAGEKHRPROC pCreateImage;
 PFNEGLDESTROYIMAGEKHRPROC pDestroyImage;
 PFNGLEGLIMAGETARGETTEXTURE2DOESPROC pImageTargetTexture;
 PFNGLEGLIMAGETARGETRENDERBUFFERSTORAGEOESPROC pImageTargetRenderbuffer;
-PFNEGLCREATESYNCKHRPROC pCreateSync;
-PFNEGLDESTROYSYNCKHRPROC pDestroySync;
-PFNEGLCLIENTWAITSYNCKHRPROC pClientWaitSync;
 
 const char *kVertex = R"(
 attribute vec2 pos;          // the unit square
@@ -403,11 +400,7 @@ bool Renderer::Init(const std::vector<uint64_t> &modifiers, std::function<void(c
     pImageTargetTexture = reinterpret_cast<PFNGLEGLIMAGETARGETTEXTURE2DOESPROC>(eglGetProcAddress("glEGLImageTargetTexture2DOES"));
     pImageTargetRenderbuffer = reinterpret_cast<PFNGLEGLIMAGETARGETRENDERBUFFERSTORAGEOESPROC>(
         eglGetProcAddress("glEGLImageTargetRenderbufferStorageOES"));
-    pCreateSync = reinterpret_cast<PFNEGLCREATESYNCKHRPROC>(eglGetProcAddress("eglCreateSyncKHR"));
+    if (!gbm_ || !pGetPlatformDisplay || !pCreateImage || !pImageTargetTexture || !pImageTargetRenderbuffer) {
-    pDestroySync = reinterpret_cast<PFNEGLDESTROYSYNCKHRPROC>(eglGetProcAddress("eglDestroySyncKHR"));
-    pClientWaitSync = reinterpret_cast<PFNEGLCLIENTWAITSYNCKHRPROC>(eglGetProcAddress("eglClientWaitSyncKHR"));
-    if (!gbm_ || !pGetPlatformDisplay || !pCreateImage || !pImageTargetTexture || !pImageTargetRenderbuffer ||
-        !pCreateSync || !pDestroySync || !pClientWaitSync) {
         std::fprintf(stderr, "handcut: GBM or EGL extensions missing\n");
         return false;
     }
@@ -458,9 +451,6 @@ void Renderer::Forget(const void *key) {
     glDeleteTextures(1, &it->second.tex);
     pDestroyImage(EGLDisplay(dpy_), EGLImageKHR(it->second.image));
     imported_.erase(it);
-    for (auto &[k, r] : rings_)   // a new buffer at the same address isn't this one
-        for (Output &o : r.out)
-            if (o.key == key) o.drawn = false;
 }
 
 bool Renderer::MakeOutput(Output &o, int w, int h) {
@@ -499,7 +489,6 @@ bool Renderer::MakeOutput(Output &o, int w, int h) {
 
 void Renderer::FreeOutput(Output &o) {
     if (o.bo && released_) released_(&o);
-    if (o.fence) pDestroySync(EGLDisplay(dpy_), EGLSyncKHR(o.fence));
     if (o.fbo) glDeleteFramebuffers(1, &o.fbo);
     if (o.rb) glDeleteRenderbuffers(1, &o.rb);
     if (o.image) pDestroyImage(EGLDisplay(dpy_), EGLImageKHR(o.image));
@@ -516,68 +505,26 @@ void Renderer::DropPanel(int panel) {
     rings_.erase(it);
 }
 
-namespace {
+const Output *Renderer::Composite(int panel, const void *key, const ft_dmabuf &src, const std::vector<Capsule2D> eyes[2]) {
-
+    if (!ready_) return nullptr;
-// The pixels a cutout's quad covers (see Draw), as x0 y0 x1 y1 in the eye's half.
+    const auto t0 = std::chrono::steady_clock::now();
-void Bounds(const Capsule2D &c, float b[4]) {
+    const int w = src.width, h = src.height;
-    const float feather = std::max(1.5f, 0.15f * std::min(c.ra, c.rb));
+    Ring &ring = rings_[panel];
-    const float r = std::max(c.ra, c.rb) + feather;
+    if (ring.w != w || ring.h != h) {
-    b[0] = std::min(c.ax, c.bx) - r, b[1] = std::min(c.ay, c.by) - r;
+        for (Output &old : ring.out) FreeOutput(old);
-    b[2] = std::max(c.ax, c.bx) + r, b[3] = std::max(c.ay, c.by) + r;
+        ring.w = w, ring.h = h, ring.next = 0;
-}
-
-// Within a quarter pixel: the same picture.
-bool SameSpots(const std::vector<Capsule2D> a[2], const std::vector<Capsule2D> b[2]) {
-    for (int e = 0; e < 2; ++e) {
-        if (a[e].size() != b[e].size()) return false;
-        for (size_t i = 0; i < a[e].size(); ++i) {
-            const Capsule2D &p = a[e][i], &q = b[e][i];
-            for (float d : {p.ax - q.ax, p.ay - q.ay, p.bx - q.bx, p.by - q.by, p.ra - q.ra, p.rb - q.rb})
-                if (std::fabs(d) > 0.25f) return false;
-        }
     }
-    return true;
+    Output &o = ring.out[ring.next];
-}
+    if (!o.bo && !MakeOutput(o, 2 * w, h)) return nullptr;
+    const GLuint tex = Texture(key, src);
+    if (!tex) return nullptr;
+    ring.next = (ring.next + 1) % 3;
 
-int64_t SteadyNs() {
-    return std::chrono::duration_cast<std::chrono::nanoseconds>(std::chrono::steady_clock::now().time_since_epoch()).count();
-}
-
-}  // namespace
-
-bool Renderer::Passed(Output &o, int64_t timeoutNs) {
-    if (!o.fence) return true;
-    const EGLint r = pClientWaitSync(EGLDisplay(dpy_), EGLSyncKHR(o.fence), 0, EGLTimeKHR(timeoutNs));
-    if (r == EGL_TIMEOUT_EXPIRED_KHR) return false;
-    pDestroySync(EGLDisplay(dpy_), EGLSyncKHR(o.fence));   // passed, or failed: don't wait on it again
-    o.fence = nullptr;
-    return true;
-}
-
-// Draws one buffer. Partial: the buffer holds this client frame already, with o.spots cut
-// out, so each eye is drawn again only inside the box around those and the new cutouts.
-void Renderer::Draw(Output &o, unsigned tex, int w, int h, const std::vector<Capsule2D> eyes[2], bool partial) {
     glBindFramebuffer(GL_FRAMEBUFFER, o.fbo);
     glBindBuffer(GL_ARRAY_BUFFER, vbo_);
     glEnableVertexAttribArray(0);
     glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, 0, nullptr);
     for (int e = 0; e < 2; ++e) {
-        if (partial) {
-            float box[4] = {1e9f, 1e9f, -1e9f, -1e9f}, b[4];
-            const std::vector<Capsule2D> *lists[2] = {&o.spots[e], &eyes[e]};
-            for (const std::vector<Capsule2D> *list : lists)
-                for (const Capsule2D &c : *list) {
-                    Bounds(c, b);
-                    box[0] = std::min(box[0], b[0]), box[1] = std::min(box[1], b[1]);
-                    box[2] = std::max(box[2], b[2]), box[3] = std::max(box[3], b[3]);
-                }
-            // Window y is the buffer's row, the same way down as the cutouts' y (see kVertex).
-            const int x0 = std::clamp(int(std::floor(box[0])) - 1, 0, w), y0 = std::clamp(int(std::floor(box[1])) - 1, 0, h);
-            const int x1 = std::clamp(int(std::ceil(box[2])) + 1, 0, w), y1 = std::clamp(int(std::ceil(box[3])) + 1, 0, h);
-            if (x1 <= x0 || y1 <= y0) continue;   // no cutout in this eye, then or now
-            glEnable(GL_SCISSOR_TEST);
-            glScissor(e * w + x0, y0, x1 - x0, y1 - y0);
-        }
         glViewport(e * w, 0, w, h);
         glDisable(GL_BLEND);
         glUseProgram(copyProg_);
@@ -596,69 +543,22 @@ void Renderer::Draw(Output &o, unsigned tex, int w, int h, const std::vector<Cap
                     uB = glGetUniformLocation(cutProg_, "b"), uR = glGetUniformLocation(cutProg_, "r"),
                     uF = glGetUniformLocation(cutProg_, "feather");
         for (const Capsule2D &c : eyes[e]) {
-            float b[4];
+            const float feather = std::max(1.5f, 0.15f * std::min(c.ra, c.rb));
-            Bounds(c, b);
+            const float r = std::max(c.ra, c.rb) + feather;
-            glUniform4f(uRect, b[0], b[1], b[2], b[3]);
+            glUniform4f(uRect, std::min(c.ax, c.bx) - r, std::min(c.ay, c.by) - r, std::max(c.ax, c.bx) + r,
+                        std::max(c.ay, c.by) + r);
             glUniform2f(uA, c.ax, c.ay);
             glUniform2f(uB, c.bx, c.by);
             glUniform2f(uR, c.ra, c.rb);
-            glUniform1f(uF, std::max(1.5f, 0.15f * std::min(c.ra, c.rb)));
+            glUniform1f(uF, feather);
             glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
         }
-        glDisable(GL_SCISSOR_TEST);
     }
     glDisable(GL_BLEND);
-}
+    // SteamVR reads the buffer from another process and GPU queue; make sure it's done.
-
+    glFinish();
-const Output *Renderer::Composite(int panel, const void *key, uint64_t serial, const ft_dmabuf &src,
+    lastMs_ = std::chrono::duration<double, std::milli>(std::chrono::steady_clock::now() - t0).count();
-                                  const std::vector<Capsule2D> eyes[2]) {
+    return &o;
-    if (!ready_) return nullptr;
-    const int64_t t0 = SteadyNs();
-    const int w = src.width, h = src.height;
-    Ring &ring = rings_[panel];
-    if (ring.w != w || ring.h != h) {
-        for (Output &old : ring.out) FreeOutput(old);
-        ring.w = w, ring.h = h, ring.shown = ring.before = ring.drawing = -1;
-    }
-    // After a pause the panel showed its client buffer, so nothing of ours is on it.
-    if (t0 - ring.lastCall > 30'000'000) ring.shown = ring.before = -1;
-    ring.lastCall = t0;
-    auto promote = [&ring] {
-        ring.before = ring.shown, ring.shown = ring.drawing, ring.drawing = -1;
-    };
-    if (ring.drawing >= 0 && Passed(ring.out[ring.drawing], 0)) promote();
-
-    const int newest = ring.drawing >= 0 ? ring.drawing : ring.shown;
-    const Output *n = newest >= 0 ? &ring.out[newest] : nullptr;
-    if (n && n->key == key && n->serial == serial && SameSpots(n->spots, eyes)) {
-        ++stats_.same;
-    } else if (ring.drawing >= 0) {
-        ++stats_.busy;   // drawn on a later tick, from what's current then
-    } else {
-        int i = 0;
-        while (i == ring.shown || i == ring.before) ++i;
-        Output &o = ring.out[i];
-        if (!o.bo && !MakeOutput(o, 2 * w, h)) return nullptr;
-        const GLuint tex = Texture(key, src);
-        if (!tex) return nullptr;
-        const bool partial = o.drawn && o.key == key && o.serial == serial;
-        Draw(o, tex, w, h, eyes, partial);
-        o.fence = pCreateSync(EGLDisplay(dpy_), EGL_SYNC_FENCE_KHR, nullptr);
-        glFlush();
-        if (!o.fence) glFinish();   // no fence: wait here, as before
-        o.key = key, o.serial = serial, o.drawn = true;
-        for (int e = 0; e < 2; ++e) o.spots[e] = eyes[e];
-        ring.drawing = i;
-        ++stats_.draws, stats_.partial += partial;
-    }
-    // Nothing of ours to show yet: wait for this one rather than show none.
-    if (ring.shown < 0 && ring.drawing >= 0) {
-        ++stats_.waits;
-        if (Passed(ring.out[ring.drawing], 50'000'000)) promote();
-    }
-    lastMs_ = (SteadyNs() - t0) / 1e6;
-    stats_.cpuMs += lastMs_, stats_.worstMs = std::max(stats_.worstMs, lastMs_);
-    return ring.shown >= 0 ? &ring.out[ring.shown] : nullptr;
 }
 
 }  // namespace handcut

screens/handcut.h

@@ -70,7 +70,7 @@ private:
     std::map<uint32_t, Motion> motion_;
     std::vector<Capsule> world_;  // base_, moved ahead
     bool predict_ = true;
-    int64_t leadNs_ = 36'000'000;   // 25 ms to the displays, plus the tick a cutout buffer waits for its fence
+    int64_t leadNs_ = 25'000'000;
     int fd_ = -1;
     const void *map_ = nullptr;
     uint64_t seq_ = 0;
@@ -91,22 +91,6 @@ struct Output {
     void *bo = nullptr;
     unsigned fbo = 0, rb = 0;
     void *image = nullptr;
-    // What's drawn in it: the client buffer and its frame, and the cutouts (a later draw
-    // with the same frame only redraws around the old and new cutouts).
-    void *fence = nullptr;        // the GPU is still drawing it
-    const void *key = nullptr;
-    uint64_t serial = 0;
-    bool drawn = false;
-    std::vector<Capsule2D> spots[2];
-};
-
-// Composite's counts since the last TakeStats.
-struct CutStats {
-    int draws = 0, partial = 0;   // buffers drawn, of them only around the cutouts
-    int same = 0;                 // nothing changed: the newest buffer stays
-    int busy = 0;                 // the GPU hadn't finished the last one: drawn next tick
-    int waits = 0;                // a panel's first buffer, waited for
-    double cpuMs = 0, worstMs = 0;
 };
 
 class Renderer {
@@ -115,34 +99,20 @@ public:
     // modifiers: what SteamVR takes for DRM_FORMAT_ABGR8888, the outputs' format.
     // released: an output is about to be freed (drop its SteamVR import).
     bool Init(const std::vector<uint64_t> &modifiers, std::function<void(const Output *)> released);
-    // Draw client buffer `src` (identified by `key`; `serial` counts its frames) into a
+    // Draw client buffer `src` (identified by `key`) into the next output buffer of
-    // buffer of panel `panel`, both eyes, cutting out `eyes`. Returns the newest buffer the
+    // panel `panel`, both eyes, cutting out `eyes`. Returns that buffer, or null.
-    // GPU has finished, or null.
+    const Output *Composite(int panel, const void *key, const ft_dmabuf &src, const std::vector<Capsule2D> eyes[2]);
-    //
-    // It doesn't wait for the GPU: a buffer is drawn, fenced, and returned from a later call
-    // once the fence has passed, so what SteamVR shows is a tick behind. Each panel has three
-    // buffers: the one shown, the one shown before it (SteamVR may still be reading it), and
-    // the one being drawn. Nothing is drawn when the frame and the cutouts are what the newest
-    // buffer has, and when only the cutouts moved, a buffer that holds the same client frame
-    // is drawn again only around them. The first call after a pause (no call for 30 ms, about
-    // 3 ticks: the panel showed its client buffer meanwhile) waits for its buffer, so a stale
-    // one never shows.
-    const Output *Composite(int panel, const void *key, uint64_t serial, const ft_dmabuf &src,
-                            const std::vector<Capsule2D> eyes[2]);
     // A client buffer is going away.
     void Forget(const void *key);
     // A panel is gone: drop its outputs.
     void DropPanel(int panel);
-    // How long the last Composite took on the CPU, ms.
+    // How long the last Composite took, ms (it waits for the GPU).
     double lastMs() const { return lastMs_; }
-    CutStats TakeStats() { CutStats s = stats_; stats_ = {}; return s; }
 
 private:
     unsigned Texture(const void *key, const ft_dmabuf &src);
     bool MakeOutput(Output &o, int w, int h);
     void FreeOutput(Output &o);
-    bool Passed(Output &o, int64_t timeoutNs);
-    void Draw(Output &o, unsigned tex, int w, int h, const std::vector<Capsule2D> eyes[2], bool partial);
     bool ready_ = false;
     int drm_ = -1;
     void *gbm_ = nullptr, *dpy_ = nullptr, *ctx_ = nullptr;
@@ -151,15 +121,9 @@ private:
     std::function<void(const Output *)> released_;
     struct Imported { void *image; unsigned tex; };
     std::map<const void *, Imported> imported_;
-    struct Ring {
+    struct Ring { Output out[3]; int next = 0; int w = 0, h = 0; };
-        Output out[3];
-        int shown = -1, before = -1, drawing = -1;   // indices into out
-        int w = 0, h = 0;
-        int64_t lastCall = 0;                        // steady clock ns
-    };
     std::map<int, Ring> rings_;
     double lastMs_ = 0;
-    CutStats stats_;
 };
 
 }  // namespace handcut

screens/handtest.cpp

@@ -163,7 +163,7 @@ int main(int argc, char **argv) {
             handcut::EyePositions(head, eyes);
             cut = handcut::Project(panel, hands.capsules(), eyes, eyes2d);
         }
-        const handcut::Output *out = cut ? renderer.Composite(0, bo, 1, client, eyes2d) : nullptr;
+        const handcut::Output *out = cut ? renderer.Composite(0, bo, client, eyes2d) : nullptr;
         if (out) {
             auto it = imports.find(out);
             if (it == imports.end()) {
@@ -177,7 +177,8 @@ int main(int argc, char **argv) {
                     vr::VROverlay()->SetOverlayFlag(ov, vr::VROverlayFlags_SideBySide_Parallel, true);
                     cutting = true;
                 }
-                if (shown != it->second) shown = it->second, vr::VROverlay()->SetOverlayTexture(ov, &tex);
+                shown = it->second;
+                vr::VROverlay()->SetOverlayTexture(ov, &tex);
                 ms += renderer.lastMs(), worst = std::max(worst, renderer.lastMs());
                 ++cutFrames;
                 caps2d += eyes2d[0].size() + eyes2d[1].size();
@@ -191,12 +192,10 @@ int main(int argc, char **argv) {
         }
         ++frames;
         if (now - lastReport > 2'000'000'000) {
-            const handcut::CutStats st = renderer.TakeStats();
             std::printf("%.0f s: %d ticks, %d with a cutout (%.1f capsules per eye), composite %.2f ms avg %.2f ms worst, "
-                        "%zu hand capsules known; %d draws (%d partial), %d same, %d busy\n",
+                        "%zu hand capsules known\n",
                         (now - start) / 1e9, frames, cutFrames, cutFrames ? caps2d / 2.0 / cutFrames : 0.0,
-                        cutFrames ? ms / cutFrames : 0.0, worst, hands.capsules().size(), st.draws, st.partial, st.same,
+                        cutFrames ? ms / cutFrames : 0.0, worst, hands.capsules().size());
-                        st.busy);
             std::fflush(stdout);
             lastReport = now, frames = cutFrames = 0, ms = worst = 0, caps2d = 0;
         }

screens/vr.cpp

@@ -43,6 +43,10 @@
 //     own; also for flatscreen games, which aren't scene apps).
 //   - during a VR game the screens hide unless the dashboard is open (g_inGames, default),
 //     or stay visible over it; the hotkey still shows them.
+//   - paused ("pause on", from the input relay when Frametop pauses for a VR game,
+//     input/game_pause.py): every screen and floating window hides whatever the mode, the
+//     hotkey, or the dashboard says, and compositor.c gives KWin a frame callback once a
+//     second instead of 90 times, so KWin and its apps hardly draw. "pause off" undoes it.
 //   - hand cutouts (handcut.cpp): where ft-hands (hands/) tracks a hand between an eye and a
 //     screen, that eye sees through the screen (to Room View). Only then is the screen
 //     drawn by us, into a side-by-side buffer (one half per eye); otherwise its client
@@ -270,9 +274,7 @@ struct Screen {
     const void *key = nullptr;    // the client buffer on it now, and its dmabuf (for cutouts)
     ft_dmabuf buf{};
     vr::SharedTextureHandle_t plain = 0;  // that buffer's SteamVR import
-    uint64_t frames = 0;          // client frames presented (a cutout buffer's "serial")
     bool cutting = false;         // showing a cutout buffer (side by side) instead
-    vr::SharedTextureHandle_t cutShown = 0;  // ...this one
     double chrome = 0.3;          // the bar's width; the other controls follow it (ChromeSize)
     double grip = 0.04;           // the corner tab's and the round buttons' size
     // A floating window's panel (see the top): the window's rectangle in the buffer, its
@@ -322,6 +324,7 @@ double g_gestureAngle = 20;  // gesture: look within this of the controller
 std::string g_gestureHand = "left";
 Lasers g_lasers = Lasers::OutsideGames;  // when controllers' lasers work the screens (see the top)
 bool g_gameRunning = false;              // a scene app (VR game) is running
+bool g_paused = false;                   // Frametop paused for a VR game: everything hidden (see the top)
 InGames g_inGames = InGames::Hide;       // during a VR game, the always mode acts like the dashboard mode
 
 // ---------------------------------------------------------------- chrome (bar, button, handle)
@@ -736,6 +739,7 @@ void UpdateGame() {
 }
 
 bool ModeVisible() {
+    if (g_paused) return false;
     switch (EffectiveMode()) {
         case Mode::Always: return !g_manual;
         case Mode::Toggle: return g_manual;
@@ -794,7 +798,7 @@ void UpdateVisibility() {
     Mat head;
     const bool haveHead = DevicePose(vr::k_unTrackedDeviceIndex_Hmd, &head);
     for (auto &[i, s] : g_screens) {
-        bool visible = s.shown && (shared || s.drag != Drag::None) && !s.alone;
+        bool visible = !g_paused && s.shown && (shared || s.drag != Drag::None) && !s.alone;
         // A floating window's panel: while a window floats on it, its output is on, and the
         // window isn't minimized (and once it has a crop).
         if (s.floating) visible = visible && s.floatOn && s.outputOn && !s.minimized && s.cropW > 0;
@@ -1440,7 +1444,7 @@ void StopCutting(Screen &s) {
     vr::VROverlay()->SetOverlayFlag(s.overlay, vr::VROverlayFlags_SideBySide_Parallel, false);
     vr::VROverlay()->SetOverlayFlag(s.overlay, vr::VROverlayFlags_IgnoreTextureAlpha, true);
     if (s.plain) SetScreenTexture(s, s.plain);
-    s.cutting = false, s.cutShown = 0;
+    s.cutting = false;
 }
 
 // Each tick: for each visible screen with a hand in front of it (for either eye), draw its
@@ -1461,7 +1465,7 @@ void UpdateCutouts() {
         bool cut = hands && s.visible && !s.floating && s.key && s.width > 0 && ScreenPose(s, &p) &&
                    handcut::Project({p, s.metres, s.heightMetres(), s.curve, s.width, s.height}, g_hands.capsules(),
                                     eyes, spots);
-        const handcut::Output *out = cut && CutterReady() ? g_cutter.Composite(i, s.key, s.frames, s.buf, spots) : nullptr;
+        const handcut::Output *out = cut && CutterReady() ? g_cutter.Composite(i, s.key, s.buf, spots) : nullptr;
         const vr::SharedTextureHandle_t h = out ? ImportCutout(out) : 0;
         if (!h) {
             StopCutting(s);
@@ -1472,7 +1476,7 @@ void UpdateCutouts() {
             vr::VROverlay()->SetOverlayFlag(s.overlay, vr::VROverlayFlags_SideBySide_Parallel, true);
             s.cutting = true;
         }
-        if (h != s.cutShown) SetScreenTexture(s, h), s.cutShown = h;   // the same buffer stays: no new frame for SteamVR
+        SetScreenTexture(s, h);
     }
 }
 
@@ -1571,6 +1575,7 @@ int ft_vr_modifiers(uint32_t format, uint64_t *out, int max) {
 }
 
 bool ft_vr_screens_shown(void) { return g_vr && ModeVisible(); }
+bool ft_vr_paused(void) { return g_paused; }
 
 }  // extern "C"
 
@@ -1701,7 +1706,7 @@ bool ft_vr_screen_present(int index, const void *key, const struct ft_dmabuf *b)
         PlaceChrome(s);  // the height changed
         std::printf("screen %d: %dx%d\n", index + 1, s.width, s.height);
     }
-    s.key = key, s.buf = *b, s.plain = it->second, ++s.frames;
+    s.key = key, s.buf = *b, s.plain = it->second;
     // While cutting, the next tick draws the new buffer with the cutouts (never floating).
     if (!s.cutting) SetScreenTexture(s, it->second);
     vr::SharedTextureHandle_t handle = it->second;
@@ -2106,6 +2111,17 @@ void ft_vr_command(const char *cmd, char *reply, int size) {
         g_manual = always ? !want : want;
         UpdateVisibility();
         std::snprintf(reply, size, "ok %s", want ? "shown" : "hidden");
+    } else if (std::sscanf(cmd, "pause %15s", word) == 1) {
+        if (!std::strcmp(word, "on") || !std::strcmp(word, "off")) {
+            const bool on = !std::strcmp(word, "on");
+            if (on != g_paused)
+                std::printf("%s\n", on ? "paused for a VR game: everything hidden, KWin slowed down" : "resumed");
+            g_paused = on;
+            UpdateVisibility();
+        } else if (std::strcmp(word, "state") != 0) {
+            return (void)std::snprintf(reply, size, "error pause on|off|state");
+        }
+        std::snprintf(reply, size, "ok %s", g_paused ? "paused" : "running");
     } else if (std::sscanf(cmd, "ingames %15s", word) == 1) {
         if (!std::strcmp(word, "hide")) g_inGames = InGames::Hide;
         else if (!std::strcmp(word, "visible")) g_inGames = InGames::Visible;
@@ -2133,18 +2149,9 @@ void ft_vr_command(const char *cmd, char *reply, int size) {
             g_hands.SetPrediction(g_hands.predicting(), ms);
         else if (std::strcmp(word, "state") != 0)
             return (void)std::snprintf(reply, size, "error cutouts on|off|state|predict on|off|lead <ms>");
-        // Composite's counts since the last state, per second.
+        std::snprintf(reply, size, "ok %s %s %.2f ms, predict %s lead %.0f ms", g_cutouts ? "on" : "off",
-        static auto since = Clock::now();
+                      g_cutterState > 0 ? "ready" : g_cutterState < 0 ? "unavailable" : "idle", g_cutter.lastMs(),
-        const double dt = std::max(1e-3, std::chrono::duration<double>(Clock::now() - since).count());
+                      g_hands.predicting() ? "on" : "off", g_hands.leadMs());
-        since = Clock::now();
-        const handcut::CutStats c = g_cutter.TakeStats();
-        const int calls = c.draws + c.same + c.busy;
-        std::snprintf(reply, size,
-                      "ok %s %s %.2f ms, predict %s lead %.0f ms; per s: %.1f draws (%.1f partial), %.1f same, %.1f busy, "
-                      "%.1f waits; CPU %.2f ms avg %.2f worst",
-                      g_cutouts ? "on" : "off", g_cutterState > 0 ? "ready" : g_cutterState < 0 ? "unavailable" : "idle",
-                      g_cutter.lastMs(), g_hands.predicting() ? "on" : "off", g_hands.leadMs(), c.draws / dt,
-                      c.partial / dt, c.same / dt, c.busy / dt, c.waits / dt, calls ? c.cpuMs / calls : 0.0, c.worstMs);
     } else if (int x0, y0, w0, h0, t0; std::sscanf(cmd, "float %d %lf %d %d %d %d %d", &n, &w, &x0, &y0, &w0, &h0, &t0) == 7) {
         Screen *s = Find(n);
         if (!s || !s->floating) return (void)std::snprintf(reply, size, "error no floating window panel %d", n);

screens/vr.h

@@ -36,6 +36,8 @@ void ft_vr_shutdown(void);
 int ft_vr_modifiers(uint32_t format, uint64_t *out, int max);
 // The screens are showing (by the visibility mode; not counting a wrist-pinned screen).
 bool ft_vr_screens_shown(void);
+// Frametop is paused for a VR game ("pause on"): everything is hidden, and KWin slows down.
+bool ft_vr_paused(void);
 // A panel for screen `index`, width in metres, placed in a row in front of the head.
 void ft_vr_screen_create(int index, double metres, int count);
 void ft_vr_screen_destroy(int index);

scripts/report.sh

@@ -25,6 +25,7 @@ for u in frametop-input-relay frametop-pointer frametop-power; do
   echo "$u: $(systemctl --user is-enabled $u 2>/dev/null) / $(systemctl --user is-active $u 2>/dev/null)"
 done
 echo "desktop: $(pgrep -x ft-screens >/dev/null && echo running || echo 'not running'), plasmashell: $(pgrep -c plasmashell || true)"
+echo "paused for VR games: $(cat /run/user/$(id -u)/frametop-pause.json 2>/dev/null || echo 'no (never paused since boot)')"
 LD_LIBRARY_PATH=/opt/steamvr/bin/linuxarm64 /opt/steamvr/bin/linuxarm64/vrpathreg show 2>/dev/null | sed -n '/xternal/,$p'
 
 section "What Frametop needs from SteamOS (scripts/update-check.py)"

scripts/update-check.py

@@ -12,15 +12,18 @@ This checks each one, and compares the versions with the last ones recorded as w
 From a PC: ssh frame python3 - [--mark-good] < scripts/update-check.py
 
 It only reads. It connects to SteamVR as a background app (which never starts SteamVR),
-runs `vrcmd --overlays` as the pointer helper does, and maps the eye tracker's shared
+runs `vrcmd --overlays` as the pointer helper does, maps the eye tracker's shared memory
-memory read-only. It never starts, stops, or restarts anything.
+read-only, and follows a controller on vrserver's web socket for a moment. It never starts,
+stops, or restarts anything.
 """
+import base64
 import json
 import math
 import mmap
 import os
 import platform
 import re
+import socket
 import struct
 import subprocess
 import sys
@@ -34,6 +37,8 @@ LAUNCHER = os.path.join(HOME, ".local/share/applications/deckard-nested-desktop.
 VRPATHS = os.path.join(HOME, ".config/openvr/openvrpaths.vrpath")
 BACKLIGHT = "/sys/class/backlight/ae94000.dsi.0/brightness"  # as in power/ft-powerd.cpp
 EYE_MMAP = "/dev/shm/eye-server.mmap"
+VRSERVER = "http://127.0.0.1:27062"  # its web socket: input/vrws.py
+PAUSE_STATE = f"/run/user/{os.getuid()}/frametop-pause.json"  # input/game_pause.py
 HOST_GLIBC = (2, 39)  # the newest the pointer driver may need (pointer/driver/build.sh)
 
 # Packages in the OS image that Frametop depends on, and what to try by hand when one changes.
@@ -297,11 +302,19 @@ def check_overlays(desktop_up):
 
 
 def check_services(sockets, desktop_up):
+    try:
+        with open(PAUSE_STATE) as f:
+            pause = json.load(f)
+        paused = pause["stopped"]["units"] if pause.get("paused") else []
+    except (OSError, ValueError, KeyError, TypeError):
+        paused = []
     for unit, socket in UNITS.items():
         if systemctl("is-enabled", unit) != "enabled":
             continue
         state = systemctl("is-active", unit)
-        if state != "active":
+        if state != "active" and unit + ".service" in paused:
+            report("skip", unit, "stopped while Frametop is paused for a VR game (input/ft-pause off resumes it)")
+        elif state != "active":
             report("FAIL", unit, f"{state}; see journalctl --user -u {unit}")
         elif socket and socket not in sockets:
             report("FAIL", unit, f"runs, but hasn't opened {socket}")
@@ -345,6 +358,69 @@ def check_steam_ui():
         report("warn", "Steam menu shortcut", f"{detail}; a Meta tap won't open the Steam menu (steam/ft-steam)")
 
 
+def check_vr_socket():
+    """vrserver's web socket, which the pause gesture reads the controllers from (input/vrws.py,
+    input/game_pause.py). It's undocumented: SteamVR's controller binding page uses it."""
+    label, headers = "vrserver web socket", {"Referer": f"{VRSERVER}/dashboard/controllerbinding.html"}
+    try:
+        import urllib.request
+        with urllib.request.urlopen(urllib.request.Request(f"{VRSERVER}/input/getstate.json", headers=headers),
+                                    timeout=3) as r:
+            devices = json.load(r).get("devices", [])
+    except (OSError, ValueError) as e:
+        report("FAIL", label, f"/input/getstate.json didn't answer ({e}); the pause gesture can't read the controllers")
+        return
+    found = [d for d in devices if d.get("controller_type") == "frame_controller" and d.get("root_path")
+             and d.get("side") in ("left", "right")]
+    if not found:
+        report("skip", label, "no Frame controller is on, so it wasn't checked")
+        return
+    if not all(any(c.get("path") == "/input/thumbstick/click" for c in d.get("components", [])) for d in found):
+        report("warn", label, "a controller lists no /input/thumbstick/click; the default pause gesture needs it")
+    data = b""
+    try:
+        with socket.create_connection(("127.0.0.1", 27062), timeout=3) as s:
+            key = base64.b64encode(os.urandom(16)).decode()
+            s.sendall((f"GET / HTTP/1.1\r\nHost: 127.0.0.1:27062\r\nUpgrade: websocket\r\nConnection: Upgrade\r\n"
+                       f"Sec-WebSocket-Key: {key}\r\nSec-WebSocket-Version: 13\r\nOrigin: {VRSERVER}\r\n"
+                       f"Referer: {headers['Referer']}\r\n\r\n").encode())
+            while b"\r\n\r\n" not in data:
+                chunk = s.recv(4096)
+                if not chunk:
+                    break
+                data += chunk
+            if b" 101 " not in data.split(b"\r\n", 1)[0] + b" ":
+                report("FAIL", label, "vrserver refused the web socket; the pause gesture can't read the controllers")
+                return
+            mailbox = f"frametop_check_{os.getpid()}"
+            # Every controller: one lying still (or asleep) may send nothing at all.
+            for text in [f"mailbox_open {mailbox}"] + ["mailbox_send input_server " + json.dumps(
+                    {"type": "request_input_state_updates", "device_path": d["root_path"], "returnAddress": mailbox})
+                    for d in found]:
+                payload, mask = text.encode(), os.urandom(4)
+                size = bytes([0x80 | len(payload)]) if len(payload) < 126 else bytes([0x80 | 126]) + struct.pack(">H", len(payload))
+                s.sendall(b"\x81" + size + mask + bytes(b ^ mask[i % 4] for i, b in enumerate(payload)))
+            deadline = time.monotonic() + 3
+            try:
+                while b"update_component_states" not in data and time.monotonic() < deadline:
+                    chunk = s.recv(65536)
+                    if not chunk:
+                        break
+                    data += chunk
+            except socket.timeout:
+                report("skip", label, "it took the subscription, but no controller sent anything in 3 s "
+                       "(lying still or asleep?): pick one up and check again")
+                return
+    except OSError as e:
+        report("FAIL", label, f"{e}; the pause gesture can't read the controllers")
+        return
+    if b"update_component_states" in data and b"/click" in data:
+        report("ok", label, "it still streams the controllers' buttons, which the pause gesture reads")
+    else:
+        report("FAIL", label, "no button states came, so the pause gesture can't read the controllers "
+               "(input/vrws.py: the message format changed?)")
+
+
 def check_eye_tracker():
     gaze = systemctl("is-enabled", "frametop-gaze") == "enabled"
     try:
@@ -394,6 +470,7 @@ def main():
         check_overlays(desktop_up)
         check_services(sockets, desktop_up)
         check_steam_ui()
+        check_vr_socket()
         check_eye_tracker()
 
     if args == ["--mark-good"]: