keys-test: the spin bindings (Meta+Alt+Tab, Meta+Alt+Shift+Tab), not while paused

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

README.md

@@ -57,6 +57,7 @@ If you work in the desktop for long stretches, or leave the headset on a stand,
 | While carrying a screen, sweep its laser across your other controller's ring, then let go | Pins it to that wrist, at its size and distance, as you hold it when you let go; it shows while you see its front. Grab its bar to adjust it (it stays pinned); sweep across the ring again to take it off |
 | Set a screen to On your head (Frametop Display Settings, Visibility & pins) | Pins it to your head where it is, like a HUD. Grab its bar to move it; it stays on your head |
 | Meta+Shift+R in the desktop | Puts the screens back in their layout (also in the menu as Reset Screen Layout, and mappable to a mouse button) |
+| Meta+Alt+Tab, or Meta+Alt+Shift+Tab | Spins every screen and floating window around you together, like a lazy susan, so the next one on your right (or left) glides to straight ahead, with the pointer and typing going to it. Their arrangement stays the same: the room turns instead of you. Tap again to keep going; Meta+Shift+R puts the screens back. Pinned screens stay where they are |
 | 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 |

docs/controller-click-stability.md

@@ -1,6 +1,6 @@
 # Controller desktop click stability
 
-Trigger presses reach KDE immediately, but controller motion within 8 logical
+Trigger presses reach KDE immediately, but controller motion within 32 logical
 pixels of the press stays at that position until release. Releasing without a motion outside this
 zone delivers the click at the original position, even if the hand moved during
 release. Moving outside the zone begins a normal drag immediately; returning to
@@ -13,11 +13,11 @@ floating-app title-bar carrying are unaffected. Multi-button gestures keep their
 existing behavior. A motion onto another desktop monitor starts a drag;
 cross-monitor motion is not stabilized.
 
-CLI (runtime preferences, reset to 8 on desktop restart):
+CLI (runtime preferences, reset to 32 on desktop restart):
 
 ```sh
 input/ft-clickctl status
-input/ft-clickctl threshold 8
+input/ft-clickctl threshold 32
 input/ft-clickctl threshold 0  # disable without a restart
 ```
 
@@ -29,6 +29,6 @@ This is a separate contribution from desktop mouse/controller ownership. Its
 hardware validation must check small controls, intentional text selection,
 long presses, cross-monitor dragging and simultaneous mouse use. The existing
 renderer laser remains tracked; this change stabilizes desktop input rather
-than smoothing the visual laser. Default threshold is a starting point to test.
+than smoothing the visual laser. The default was 8 at first. That's about 0.2° on a 3.4 m wide 3440-pixel screen 2 m away, and clicking took a very still hand, so it's 32 (about 0.9°) since 2026-10-03.
 
 Run `scripts/test-controller-click.sh` for the isolated gesture-state tests.

docs/design.md

@@ -38,7 +38,7 @@ The curved layout chains screens edge to edge, like monitors on a desk: the midd
 
 A resize handle has to be able to shrink a screen from any direction, so the dragged corner follows the laser along the screen's diagonal rather than taking the larger of its horizontal and vertical reach. Pushing and pulling a carried screen moves it along the line from your head, because the 3D mouse's virtual controller sits just in front of the bar, below the screen's centre, so the line from the device points mostly upward.
 
-Wherever ft-screens needs to know where a laser points (showing the controls, the resize tab, the roll knob), it uses the laser's own pose, the render model's `tip` component, rather than the controller's pose. On the Frame's controllers the tip points 40° below the pose's forward axis, so rays from the pose missed what the laser was actually on. The 3D mouse's virtual controller has no tip, and its laser runs along its pose.
+Wherever ft-screens needs to know where a laser points (showing the controls, the resize tab, the roll knob), it uses the laser's own pose, the render model's `tip` component, rather than the controller's pose. On the Frame's controllers the tip points 40° below the pose's forward axis, so rays from the pose missed what the laser was actually on. The 3D mouse's virtual controller has no tip, and its laser runs along its pose. ft-screens reads the tip with `GetComponentState`: `GetComponentStateForDevicePath` without an input source handle fails for every component while a VR game runs, so in games the rays came from the pose, 40° too high.
 
 `ComputeOverlayIntersection` ignores `SetOverlayIntersectionMask`, and a control can't be allowed to cover part of its screen, so the resize tab sits entirely outside the corner.
 
@@ -62,7 +62,7 @@ A profile's screen part is the custom arrangement under a name: each screen's po
 
 `IVRApplications::GetCurrentSceneProcessId()` is 0 when no game is running (the Frame's home environment isn't a scene app) and the game's process ID while one is. ft-screens checks it twice a second, turns the flag off while a game runs, and by default hides the screens unless the dashboard is open. Flatscreen games run inside Steam's gamescope overlay and aren't scene apps, which is why "only with the dashboard open" is offered as a controller setting.
 
-The reset button needs to work in a game, where the screens have the flag off. So ft-screens turns the flag on for that button's overlay alone while a hand controller aims within about one button's width of it, and off half a second after the aim leaves a zone twice as wide. ft-screens finds the aim from the controllers' laser poses, which it reads anyway to show the controls, so it doesn't need SteamVR's laser to be on first. The game loses the controllers only while you aim at the button.
+In a game, Frametop's panels work like SteamVR's own floating windows: point a controller at one and its laser comes on, point away and the game has the controllers again. ft-screens turns the flag on for a panel while a hand controller's laser pose meets it, its controls, or a floating window's popups. It finds that from the poses it already reads to show the controls, so SteamVR's laser doesn't have to be on first. Leaving takes a margin two control-sizes wide and 0.3 s, a drag or a held button keeps the flag on, and the keyboard, a single overlay, uses SteamVR's `ComputeOverlayIntersection`. The 3D mouse doesn't need any of this: it has its own laser mode.
 
 ## Floating windows
 

docs/reference.md

@@ -44,7 +44,7 @@ Every screen is an overlay named `frametop.screen.N` with five controls:
 - `.curve` bends the screen into a cylinder around you, using your current distance as the radius, or makes it flat again.
 - `.roll` rolls the screen when you drag it sideways, like a knob. It snaps level within 2.5°, and scrolling on it turns 5° per notch.
 - `.resize`, the tab on the bottom right corner, sets the width. Screens go down to 15 cm wide.
-- `.reset`, left of the bar, puts every screen back in its layout around where you are now, like Meta+Shift+R (`ft-layout apply`). In a VR game, where the screens leave the controllers to the game, aiming a controller at it turns SteamVR's laser on for that button alone, so the trigger clicks it; the game gets the controllers back half a second after you aim away.
+- `.reset`, left of the bar, puts every screen back in its layout around where you are now, like Meta+Shift+R (`ft-layout apply`).
 
 The controls are sized from both the screen's width and its distance from you, follow the surface of a curved screen, and stay invisible until a laser or the 3D mouse's cursor lands on one or comes within about 1.5 times a button's size of it. While invisible they're still there, fully transparent, so SteamVR's laser can find them. They're translucent until a laser is on them, like SteamVR's own window controls.
 
@@ -62,7 +62,7 @@ The Visibility & pins tab of Frametop Display Settings decides when the screens
 In the last three modes the hotkey shows the screens anyway. A screen can also be hidden on its own (Screens shown on the same tab, or `ft-layout hide N`): it stays hidden whatever the mode or the hotkey says, until it's shown again there. Windows on it stay put, and a new window that would open on it floats instead (ft-floatd). Profiles use this to show only some screens. Two more settings on the same tab cover VR games, which ft-screens detects as SteamVR scene apps:
 
 - During VR games, the Always mode hides the screens unless the dashboard is open (the default), or leaves them up.
-- Controllers on the screens. Visible screens can keep SteamVR's laser mouse on, so controllers work them with the dashboard closed, but that also takes the controllers away from a game. By default this is off while a VR game runs, and the 3D mouse or the dashboard works the screens. The other choices are always on, or only with the dashboard open, which also suits flatscreen games since they aren't scene apps.
+- Controllers on the screens. Visible screens can keep SteamVR's laser mouse on, so controllers work them with the dashboard closed, but that also takes the controllers away from a game. By default this is off while a VR game runs, and the 3D mouse or the dashboard works the screens. Pointing a controller at a screen, a floating window, or the keyboard still turns its laser on, like SteamVR's own floating windows, and pointing away gives the game the controllers back. The other choices are always on, or only with the dashboard open, which also suits flatscreen games since they aren't scene apps.
 
 Input from the lasers reaches KWin through ft-screens' own seat. Keys come from the input relay, from pass-through keyboards and any key a pointer device passes through. Typing follows your last click: after a click on a screen it goes to the desktop, even with the SteamVR dashboard open, and after a mouse click on any other panel (the dashboard, Steam, an app like Spotify) it goes there instead. While it goes to the desktop, the relay grabs pass-through keyboards so gamescope, which reads every keyboard itself, doesn't type them into the Steam app too. A program that watches every keyboard for a hotkey loses a grabbed one; with `SHARE_KEYS=1` in `~/.config/frametop.conf`, their keys also go to `@frametop_keys` for it. That's off by default, since any local process that binds the name first would get everything typed into the desktop. Hidden screens don't take typing.
 
@@ -134,7 +134,7 @@ A Kirigami app with a Python backend, in the Plasma menu under Settings. It runs
 - 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.
+- 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), Meta+Shift+F (float window in VR or put it back), and Meta+Alt+Tab and Meta+Alt+Shift+Tab (spin the panels: every screen and floating window turns about your head, so the next one on the right or left comes to the front; ft-screens' `spin next|prev|<degrees>`); 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.
 - Gaze has the gaze pointer switch (on now and from now on; a mapped button toggles it until the helper restarts), what the mouse's left button and movement do, the gaze dot, the eye tracker and eye bias, the gaze mode sliders, the gaze service's state (headset, samples per second, how often the tracker is losing each eye, the calibration, the nudges learned), and Quick check, Calibrate, and Check headset fit (each in a panel in the headset), Reload calibration, and Forget nudges. The gaze probe, a development tool, is in the page's overflow menu.

float/frametop-float.js

@@ -378,6 +378,17 @@ function run(c) {
         case "activate":
             if (w) workspace.activeWindow = w;
             break;
+        case "activate-output": {  // the top window on that output (a spin brought it to the front)
+            const order = workspace.stackingOrder;
+            for (let i = order.length - 1; i >= 0; --i) {
+                const o = order[i];
+                if (o.deleted || o.minimized || o.hidden || !o.managed || !o.output) continue;
+                if (o.output.name !== c.output || !o.normalWindow || o.popupWindow) continue;
+                workspace.activeWindow = o;
+                break;
+            }
+            break;
+        }
         case "minimize":
             if (w) w.minimized = c.on;
             break;

float/ft_floatd.py

@@ -18,6 +18,8 @@ command-line side). Replies go to the sender:
   ("float pointer" is the float key: the window under the pointer, else the active one,
   floated or docked; the input relay sends it for float_toggle, and "dock all" for dock_all)
   dock N | close N | resize N W H | scale N STEPS                      (ft-screens, N = its screen)
+  front N   (ft-screens: a spin brought panel N to the front: make its window, or the top one
+            on a screen, KWin's active window)
 
 Spare outputs are WL-<screens> .. WL-<screens + slots - 1>. A floating window's output is its
 frame plus a margin on each side (FLOAT_MARGIN pixels), so menus have room; the panel shows
@@ -1063,6 +1065,13 @@ class Daemon:
             for f in list(self.floats.values()):
                 self.dock(f)
             return "ok"
+        if cmd == "front" and len(rest) == 1 and rest[0].isdigit():
+            f = self.by_panel(int(rest[0]))
+            if f:
+                self.command(cmd="activate", id=f.id)
+            else:  # a screen: its output is WL-<N - 1>
+                self.command(cmd="activate-output", output=f"WL-{int(rest[0]) - 1}")
+            return "ok"
         if cmd in ("dock", "close", "resize", "scale") and rest and rest[0].isdigit():
             f = self.by_panel(int(rest[0]))
             if not f:

input-settings/ft_input_settings.py

@@ -77,6 +77,8 @@ ACTION_LABELS = {
     "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)",
+    "spin_next": "Spin the panels: next one on the right to the front",
+    "spin_prev": "Spin the panels: next one on the left to the front",
     "key": "Pass through as key",
     "none": "Do nothing",
 }
@@ -163,9 +165,10 @@ GAZE_MOUSE = {"precision": "Gaze precision: hold to steer with the mouse, releas
 MODIFIER_CODES = {29: 29, 97: 29, 42: 42, 54: 42, 56: 56, 100: 56, 125: 125, 126: 125}
 MODIFIER_NAMES = {29: "Ctrl", 42: "Shift", 56: "Alt", 125: "Meta"}
 # What a rules file without "key_bindings" gets (the relay's DEFAULT_KEY_BINDINGS): a Meta tap
-# opens Steam's menu, Meta+J and Meta+K click at the gaze, Meta+Shift+F floats a window.
+# opens Steam's menu, Meta+J and Meta+K click at the gaze, Meta+Shift+F floats a window,
+# Meta+Alt+Tab and Meta+Alt+Shift+Tab spin the panels.
 DEFAULT_KEY_BINDINGS = {"125": "steam_menu", "125+36": "gaze_left", "125+37": "gaze_right",
-                        "42+125+33": "float_toggle"}
+                        "42+125+33": "float_toggle", "56+125+15": "spin_next", "42+56+125+15": "spin_prev"}
 
 
 def key_bindings(rules):

input/input-relay.py

@@ -30,7 +30,9 @@ gaze_quickcal = the gaze service's one-dot check ("quickcal" to @ft_gazed), sens
 layout_reset = put the desktop screens back in their saved layout, screens_toggle = hide or show the desktop screens,
 keyboard_toggle = open or close Frametop's keyboard, float_toggle = float the desktop window under the
 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
+window back (both to ft-floatd, @frametop_float), spin_next and spin_prev = turn every panel in the
+room about your head so the next one to the right or left comes to the front (ft-screens' "spin",
+Meta+Alt+Tab and Meta+Alt+Shift+Tab by default), 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), pause_toggle =
 pause Frametop for a VR game, or resume it (game_pause.py), command:CMD = run
@@ -209,14 +211,16 @@ 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", "pause_toggle", "key", "none")
+           "dock_all", "spin_next", "spin_prev", "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
 # and Meta+K click at the gaze (free on the Frametop desktop, and apps don't use Meta),
-# Meta+Shift+F floats a window.
+# Meta+Shift+F floats a window, and Meta+Alt+Tab and Meta+Alt+Shift+Tab spin the panels around
+# you (ft-screens' lazy susan); not Meta+Tab, which is Cmd+Tab on a Mac reached through a remote
+# desktop like RustDesk.
 DEFAULT_KEY_BINDINGS = {"125": "steam_menu", "125+36": "gaze_left", "125+37": "gaze_right",
-                        "42+125+33": "float_toggle"}
+                        "42+125+33": "float_toggle", "56+125+15": "spin_next", "42+56+125+15": "spin_prev"}
 KEY_F24 = 194  # sent to the desktop with a Meta combination (see the top)
 # Key combinations ("key_bindings"): modifiers, each side's code folded into the left one's.
 MODIFIERS = {29: 29, 97: 29, 42: 42, 54: 42, 56: 56, 100: 56, 125: 125, 126: 125}
@@ -232,6 +236,9 @@ GAZED = "\0ft_gazed"
 FLOAT = "\0frametop_float"  # ft-floatd, floating windows in the Frametop desktop
 # Actions for ft-floatd ("float_toggle", "dock_all"): they don't need pointer mode.
 FLOAT_ACTIONS = {"float_toggle": b"float pointer", "dock_all": b"dock all"}
+# Actions for ft-screens: spin_next and spin_prev turn every panel in the room about your head,
+# so the next one to the right or left comes to the front. They don't need pointer mode either.
+SCREENS_ACTIONS = {"spin_next": b"spin next", "spin_prev": b"spin prev"}
 PROFILE = "profile:"  # "profile:NAME": switch to that profile (doesn't need pointer mode either)
 COMMAND = "command:"  # "command:CMD": run CMD (nor does this)
 
@@ -242,7 +249,7 @@ def known_action(a):
 
 
 def needs_pointer(a):
-    return a not in FLOAT_ACTIONS and a not in ("steam_menu", "pause_toggle") and not a.startswith((PROFILE, COMMAND))
+    return a not in FLOAT_ACTIONS and a not in SCREENS_ACTIONS and a not in ("steam_menu", "pause_toggle") and not a.startswith((PROFILE, COMMAND))
 
 
 def works_paused(a):
@@ -925,6 +932,13 @@ def main():
                 except OSError:
                     pass  # the Frametop desktop isn't running
                 log(action)
+        elif action in SCREENS_ACTIONS:
+            if value == 1:
+                try:
+                    screens_sock.sendto(SCREENS_ACTIONS[action], SCREENS)
+                except OSError:
+                    pass  # the Frametop desktop isn't running
+                log(action)
         elif state["pointer"]:
             state["pointer"].action(action, value, now, source)
 

input/test/keys-test.py

@@ -206,7 +206,7 @@ def check(label, got, want):
         failures.append(label)
 
 
-META, RMETA, SHIFT, CTRL, RCTRL, A, F, J, P = 125, 126, 42, 29, 97, 30, 33, 36, 25
+META, RMETA, SHIFT, CTRL, RCTRL, ALT, A, F, J, P, TAB = 125, 126, 42, 29, 97, 56, 30, 33, 36, 25, 15
 F24 = ["key 194 1", "key 194 0"]
 
 
@@ -265,6 +265,20 @@ def tests():
     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"])
 
+    use(None)  # the defaults: Meta+Alt+Tab and Meta+Alt+Shift+Tab spin the panels (ft-screens)
+    key(META, 1); key(ALT, 1); key(TAB, 1); key(TAB, 0); key(ALT, 0); key(META, 0)
+    got = typed()
+    check("Meta+Alt+Tab (default): spin next", [m for m in got if m.startswith("spin")], ["spin next"])
+    check("Meta+Alt+Tab: Tab isn't typed", [m for m in got if m.startswith("key 15 ")], [])
+    key(META, 1); key(ALT, 1); key(SHIFT, 1); key(TAB, 1); key(TAB, 0); key(SHIFT, 0); key(ALT, 0); key(META, 0)
+    check("Meta+Alt+Shift+Tab (default): spin prev", [m for m in typed() if m.startswith("spin")], ["spin prev"])
+    pause("on")
+    key(META, 1); key(ALT, 1); key(TAB, 1); key(TAB, 0); key(ALT, 0); key(META, 0)
+    check("paused: Meta+Alt+Tab doesn't spin", [m for m in typed() if m.startswith("spin")], [])
+    pause("off")
+    check("spinning works without pointer mode", (relay.needs_pointer("spin_next"), relay.needs_pointer("spin_prev")),
+          (False, False))
+
     check("an empty command isn't an action", relay.known_action("command:  "), False)
     check("steam_menu, pause_toggle and commands work without pointer mode",
           (relay.needs_pointer("steam_menu"), relay.needs_pointer("pause_toggle"), relay.needs_pointer("command:ls")),

screens/compositor.c

@@ -346,6 +346,20 @@ static void handle_vr_event(const struct ft_event *e, void *data) {
     if (e->screen < 0 || e->screen >= MAX_SCREENS || !s->screens[e->screen]) return;
     struct screen *sc = s->screens[e->screen];
     struct wlr_surface *surface = sc->toplevel->base->surface;
+    if (e->type == FT_FRONT) {
+        // A spin brought this panel to the front: typing goes to it, as after a click there,
+        // and ft-floatd makes its window (or the top one on a screen) KWin's active window.
+        wlr_seat_keyboard_notify_enter(s->seat, surface, NULL, 0, NULL);
+        s->keys_clicked = true;
+        char msg[32];
+        snprintf(msg, sizeof msg, "front %d", e->screen + 1);
+        struct sockaddr_un addr = {.sun_family = AF_UNIX};
+        const char name[] = "frametop_float";
+        memcpy(addr.sun_path + 1, name, sizeof name - 1);
+        sendto(s->relay_fd, msg, strlen(msg), MSG_DONTWAIT, (struct sockaddr *)&addr,
+               offsetof(struct sockaddr_un, sun_path) + 1 + sizeof name - 1);
+        return;
+    }
     const uint32_t t = now_ms();
     const double x = e->x / s->scale[e->screen], y = e->y / s->scale[e->screen];  // KWin's units
     switch (e->type) {
@@ -795,7 +809,9 @@ static bool setup_dmabuf(struct server *s) {
 
 int main(int argc, char **argv) {
     struct server s = {0};
-    s.controller_click.threshold = 8;
+    // About 0.9 degrees on a 3.4 m wide 3440-pixel screen 2 m away; 8 (the first default,
+    // about 0.2 degrees) needed a very still hand to click (headset test 2026-10-03).
+    s.controller_click.threshold = 32;
     for (int i = 0; i < MAX_SCREENS; ++i) s.scale[i] = 1;
     s.kb_screen = -1;
     s.rate[FT_FOCUSED] = 0, s.rate[FT_IN_VIEW] = 15, s.rate[FT_HIDDEN] = 1;

screens/keyboard.cpp

@@ -459,7 +459,21 @@ void Hide() {
 bool Shown() { return g_shown; }
 
 void SetLasers(bool on) {
-    if (Create()) vr::VROverlay()->SetOverlayFlag(g_overlay, vr::VROverlayFlags_MakeOverlaysInteractiveIfVisible, on);
+    static vr::VROverlayHandle_t set = vr::k_ulOverlayHandleInvalid;  // the overlay `was` is for
+    static bool was = false;
+    if (!Create() || (set == g_overlay && was == on)) return;
+    set = g_overlay, was = on;
+    vr::VROverlay()->SetOverlayFlag(g_overlay, vr::VROverlayFlags_MakeOverlaysInteractiveIfVisible, on);
+}
+
+bool Aimed(const vr::HmdMatrix34_t &laser) {
+    if (!g_shown) return false;
+    vr::VROverlayIntersectionParams_t in{};
+    in.eOrigin = vr::TrackingUniverseStanding;
+    in.vSource = {laser.m[0][3], laser.m[1][3], laser.m[2][3]};
+    in.vDirection = {-laser.m[0][2], -laser.m[1][2], -laser.m[2][2]};
+    vr::VROverlayIntersectionResults_t out{};
+    return vr::VROverlay()->ComputeOverlayIntersection(g_overlay, &in, &out);
 }
 
 void Poll(void (*handle)(const Event &, void *), void *data) {

screens/keyboard.h

@@ -26,6 +26,8 @@ const vr::HmdMatrix34_t &Pose();
 void EndDragBy(uint32_t device);
 // Controllers' lasers work the panel with the dashboard closed, like the screens'.
 void SetLasers(bool on);
+// A laser (its pose, aiming along -z) points at the panel.
+bool Aimed(const vr::HmdMatrix34_t &laser);
 // The panel's input: key presses and releases, and Closed for its Close key.
 void Poll(void (*handle)(const Event &, void *), void *data);
 void Destroy();

screens/vr.cpp

@@ -12,9 +12,7 @@
 //   - a resize tab on the bottom right corner: drag it to set the width (the height
 //     follows the screen's resolution).
 //   - a reset button left of the bar: every screen back in its layout, around where you
-//     are now (`ft-layout apply`, like Meta+Shift+R). Where the screens leave the
+//     are now (`ft-layout apply`, like Meta+Shift+R).
-//     controllers to a VR game, aiming a controller at it turns SteamVR's laser mouse on for
-//     that button alone (UpdateResetLaser), so it can be clicked in a game.
 //   The controls are translucent, like SteamVR's own, and brighten under a laser. They
 //   are invisible until a laser (a controller's, or the 3D mouse's) lands on or passes very close to
 //   one of them (UpdateControls).
@@ -44,7 +42,10 @@
 //     default it's off while a game (a scene app) runs: the screens stay up over the game,
 //     the controllers stay in it, and the 3D mouse (its own laser mode) or the dashboard
 //     works the screens. Modes: always, outside_games (default), dashboard (never on its
-//     own; also for flatscreen games, which aren't scene apps).
+//     own; also for flatscreen games, which aren't scene apps). Where the mode leaves the
+//     controllers to the game, pointing a controller at a panel (a screen, a floating window
+//     and its popups, their controls, the keyboard) turns the laser on for it until you
+//     point away, like SteamVR's own floating windows (UpdateAim).
 //   - 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,
@@ -189,8 +190,12 @@ Mat TipOffset(vr::TrackedDeviceIndex_t dev) {
     Tip tip{model, Identity(), false, now};
     vr::RenderModel_ControllerMode_State_t mode{};
     vr::RenderModel_ComponentState_t state{};
-    if (model[0] && vr::VRRenderModels()->GetComponentStateForDevicePath(model, vr::k_pch_Controller_Component_Tip,
+    // GetComponentState, not GetComponentStateForDevicePath: without an input source handle
-                                                                          vr::k_ulInvalidInputValueHandle, &mode, &state))
+    // the latter fails for every component while a VR game runs, and the rays came from the
+    // pose, 40 degrees above the laser. The tip doesn't move with the buttons.
+    vr::VRControllerState_t buttons{};
+    if (model[0] && vr::VRRenderModels()->GetComponentState(model, vr::k_pch_Controller_Component_Tip, &buttons, &mode,
+                                                            &state))
         tip.offset = state.mTrackingToComponentLocal, tip.found = true;
     cache[dev] = tip;
     return tip.offset;
@@ -237,7 +242,7 @@ constexpr double kRollSnap = 2.5;    // degrees from level where rolling snaps l
 constexpr double kRollStep = 5;      // degrees per scroll notch on the roll button
 constexpr float kChromeIdle = 0.55f; // the controls' opacity without a laser on them
 constexpr long kControlsLinger = 35; // ticks (~0.4 s) the controls stay after a laser leaves
-constexpr long kResetLinger = 45;    // ticks (~0.5 s) the reset button keeps the laser mouse on
+constexpr long kAimLinger = 25;      // ticks (~0.3 s) a panel keeps the laser on after the aim leaves it
 long g_tick = 0;                     // ft_vr_poll calls
 bool g_vr = false;                   // connected to SteamVR (ft-screens --no-vr runs without it)
 constexpr vr::TrackedDeviceIndex_t kNone = vr::k_unTrackedDeviceIndexInvalid;
@@ -275,8 +280,7 @@ struct Screen {
     float controls = 0;                       // the controls' fade, 0 (hidden) .. 1
     bool controlsUp = false;                  // the controls' overlays are shown
     long nearUntil = 0;                       // a laser was near the controls until this tick
-    long resetNearUntil = 0;                  // a hand controller aimed at the reset button until this tick
+    long aimUntil = 0;                        // a hand controller pointed at it until this tick (UpdateAim)
-    bool resetLaser = false;                  // the reset button has MakeOverlaysInteractiveIfVisible
     vr::TrackedDeviceIndex_t pinTarget = kNone;  // moving: rides on this controller when let go
     vr::TrackedDeviceIndex_t onWrist = kNone;    // moving: the laser is in this controller's ring
     bool barLit = false;
@@ -910,26 +914,20 @@ void UpdateAttention() {
 
 
 // Controllers' lasers on the screens (see the top): the flag follows the mode and whether a
-// VR game runs.
+// VR game runs, and where the mode leaves the controllers to the game, whether one points at
+// the panel (UpdateAim).
+bool LasersByMode() { return g_lasers == Lasers::Always || (g_lasers == Lasers::OutsideGames && !g_gameRunning); }
+long g_keyboardAimUntil = 0;
+
 void UpdateLasers() {
-    const bool want = g_lasers == Lasers::Always || (g_lasers == Lasers::OutsideGames && !g_gameRunning);
+    const bool byMode = LasersByMode();
     for (auto &[i, s] : g_screens) {
+        const bool want = byMode || (s.visible && g_tick < s.aimUntil);
         if (s.lasers == want) continue;
         s.lasers = want;
         vr::VROverlay()->SetOverlayFlag(s.overlay, vr::VROverlayFlags_MakeOverlaysInteractiveIfVisible, want);
     }
-}
+    if (keyboard::Shown()) keyboard::SetLasers(byMode || g_tick < g_keyboardAimUntil);
-
-// The reset button in a VR game (or the dashboard mode), where the screens don't keep
-// SteamVR's laser mouse on: aiming a hand controller at it turns the laser mouse on for that
-// button alone, so the trigger clicks it, and the game gets the controllers back
-// kResetLinger ticks after the aim leaves it (a wider zone than the one that turns it on).
-void UpdateResetLaser(Screen &s) {
-    const bool want = s.resetButton != vr::k_ulOverlayHandleInvalid && s.visible && !s.lasers &&
-                      g_tick < s.resetNearUntil;
-    if (want == s.resetLaser) return;
-    s.resetLaser = want;
-    vr::VROverlay()->SetOverlayFlag(s.resetButton, vr::VROverlayFlags_MakeOverlaysInteractiveIfVisible, want);
 }
 
 // The distance from a laser's line to a point ahead of it, or -1 when it's behind.
@@ -947,11 +945,10 @@ double RayDistance(const Mat &d, const Mat &c) {
 // kControlsLinger ticks after it leaves, and while in use.
 void UpdateControls() {
     std::vector<Mat> lasers;
-    std::vector<bool> hands;  // the laser is a hand controller's (not the 3D mouse's)
     for (vr::TrackedDeviceIndex_t i = 1; i < vr::k_unMaxTrackedDeviceCount; ++i) {
         Mat d;
         if (vr::VRSystem()->GetTrackedDeviceClass(i) == vr::TrackedDeviceClass_Controller && LaserPose(i, &d))
-            lasers.push_back(d), hands.push_back(IsHandController(i));
+            lasers.push_back(d);
     }
     for (auto &[i, s] : g_screens) {
         Mat p;
@@ -977,16 +974,7 @@ void UpdateControls() {
                     break;
                 }
             }
-            if (s.resetButton != vr::k_ulOverlayHandleInvalid && !s.lasers) {
-                const Mat c = Mul(p, offsets[6]);
-                const double aim = s.grip * (s.resetLaser ? 2.0 : 0.9);
-                for (size_t k = 0; k < lasers.size(); ++k) {
-                    const double r = RayDistance(lasers[k], c);
-                    if (hands[k] && r >= 0 && r <= aim) s.resetNearUntil = g_tick + kResetLinger;
-                }
-            }
         }
-        UpdateResetLaser(s);
         const bool inUse = s.drag != Drag::None || std::any_of(std::begin(s.hover), std::end(s.hover), [](bool h) { return h; });
         const bool want = s.visible && (inUse || g_tick < s.nearUntil);
         // The controls stay shown while their screen is, just fully transparent when not
@@ -1020,19 +1008,21 @@ void SendFloat(const std::string &msg) {
         std::printf("to ft-floatd: %s\n", msg.c_str());
 }
 
-// A new panel: the pointer helper reads SteamVR's list of panels only every 20 s, so it's told
+// To the pointer helper (@ft_pointer_helper), from an unbound socket.
-// at once ("overlay <key>"), or the mouse couldn't click a menu until then.
+void SendPointer(const std::string &msg) {
-void AnnounceOverlay(const char *key) {
     static const int fd = socket(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0);
     sockaddr_un addr{};
     addr.sun_family = AF_UNIX;
     const char name[] = "ft_pointer_helper";
     std::memcpy(addr.sun_path + 1, name, sizeof name - 1);
-    const std::string msg = std::string("overlay ") + key;
     sendto(fd, msg.data(), msg.size(), MSG_DONTWAIT, reinterpret_cast<sockaddr *>(&addr),
            socklen_t(offsetof(sockaddr_un, sun_path) + 1 + sizeof name - 1));
 }
 
+// A new panel: the pointer helper reads SteamVR's list of panels only every 20 s, so it's told
+// at once ("overlay <key>"), or the mouse couldn't click a menu until then.
+void AnnounceOverlay(const char *key) { SendPointer(std::string("overlay ") + key); }
+
 // Where a device's ray meets the screen's plane, in the screen's x (right) and y (up),
 // metres from its centre.
 bool RayOnPlane(const Mat &p, const Mat &d, double *x, double *y) {
@@ -1500,6 +1490,137 @@ Screen *Find(int one_based) {
     return it == g_screens.end() ? nullptr : &it->second;
 }
 
+// ---------------------------------------------------------------- the lazy susan
+// "spin next|prev|<degrees>": the panels in the room (screens and floating windows, not
+// pinned ones) turn together about a vertical axis through your head, so the next panel to
+// your right (next) or left (prev) glides to straight ahead, or the ring turns by that many
+// degrees (positive turns it left, like next). Their arrangement stays as it is: the room
+// turns instead of you. A spin that arrives during one adds to it, from where the panels are
+// headed, so quick taps carry on smoothly. Grabbing a panel, or a command that places it,
+// takes it out of the spin where it is. The 3D mouse's pointer goes to straight ahead.
+constexpr double kSpinSeconds = 0.3;  // how long a spin takes
+constexpr double kSpinAhead = 8;      // degrees: a panel this near straight ahead is the current one
+constexpr double kSpinFocus = 30;     // degrees: when a spin settles, the panel this near ahead gets typing
+
+struct Spin {
+    bool on = false;
+    double cx = 0, cz = 0;    // the axis
+    double from = 0, to = 0;  // radians, turned from the poses in base (positive: to the left)
+    Clock::time_point start;
+    std::map<int, Mat> base;  // index -> its pose before the spin
+    int front = -1;           // settled: this panel came to the front (ft_vr_poll reports it)
+} g_spin;
+
+// p turned a radians about the vertical axis through (cx, cz); positive turns it to the left.
+Mat Turned(const Mat &p, double a, double cx, double cz) {
+    const double c = std::cos(a), s = std::sin(a);
+    Mat r = Identity();
+    r.m[0][0] = float(c), r.m[0][2] = float(s);
+    r.m[2][0] = float(-s), r.m[2][2] = float(c);
+    r.m[0][3] = float(cx - c * cx - s * cz);
+    r.m[2][3] = float(cz + s * cx - c * cz);
+    return Mul(r, p);
+}
+
+bool Spinnable(const Screen &s) { return s.pinned == kNone && (!s.floating || s.floatOn) && s.drag == Drag::None; }
+
+double SpinNow() {
+    if (!g_spin.on) return g_spin.to;
+    const double t = std::min(1.0, std::chrono::duration<double>(Clock::now() - g_spin.start).count() / kSpinSeconds);
+    return g_spin.from + (g_spin.to - g_spin.from) * t * t * (3 - 2 * t);
+}
+
+void UpdateSpin() {
+    if (!g_spin.on) return;
+    const double a = SpinNow();
+    const bool done = Clock::now() - g_spin.start >= std::chrono::duration<double>(kSpinSeconds);
+    for (auto it = g_spin.base.begin(); it != g_spin.base.end();) {
+        auto s = g_screens.find(it->first);
+        if (s == g_screens.end() || !Spinnable(s->second)) {
+            it = g_spin.base.erase(it);  // grabbed, pinned, or gone: it stays where it is now
+            continue;
+        }
+        SetAbsolute(s->second, Turned(it->second, a, g_spin.cx, g_spin.cz));
+        ++it;
+    }
+    if (done) {
+        // The panel now nearest straight ahead (of where you face) gets typing and the active window.
+        Mat head;
+        double nearest = kSpinFocus;
+        if (DevicePose(vr::k_unTrackedDeviceIndex_Hmd, &head)) {
+            for (const auto &[i, p] : g_spin.base) {
+                const auto it = g_screens.find(i);
+                Mat q;
+                if (it == g_screens.end() || !it->second.visible || !ScreenPose(it->second, &q)) continue;
+                double f[3] = {-head.m[0][2], 0, -head.m[2][2]};
+                double d[3] = {q.m[0][3] - head.m[0][3], 0, q.m[2][3] - head.m[2][3]};
+                const double fl = std::sqrt(Dot3(f, f)), dl = std::sqrt(Dot3(d, d));
+                if (fl < 1e-6 || dl < 1e-6) continue;
+                const double a = std::acos(std::clamp(Dot3(f, d) / (fl * dl), -1.0, 1.0)) * 180 / M_PI;
+                if (a < nearest) nearest = a, g_spin.front = i;
+            }
+        }
+        g_spin.on = false;
+        g_spin.base.clear();
+        ArrangeDesktopSoon();  // KWin's outputs follow where the screens are now
+    }
+}
+
+void SpinCommand(const char *arg, char *reply, int size) {
+    Mat head;
+    if (!DevicePose(vr::k_unTrackedDeviceIndex_Hmd, &head))
+        return (void)std::snprintf(reply, size, "error no head pose (headset off?)");
+    if (g_spin.on) {
+        g_spin.from = SpinNow();  // carry on from where the panels are now
+    } else {
+        g_spin.base.clear();
+        for (auto &[i, s] : g_screens) {
+            Mat p;
+            if (Spinnable(s) && ScreenPose(s, &p)) g_spin.base[i] = p;
+        }
+        g_spin.cx = head.m[0][3], g_spin.cz = head.m[2][3];
+        g_spin.from = g_spin.to = 0;
+    }
+    if (g_spin.base.empty()) return (void)std::snprintf(reply, size, "error nothing to spin");
+    double turn;  // degrees, positive to the left
+    const bool next = !std::strcmp(arg, "next");
+    if (next || !std::strcmp(arg, "prev")) {
+        // Each visible panel's bearing from where you face, to the right positive, as it will
+        // be when the spin so far ends; the nearest one past straight ahead comes to the front.
+        double fx = -head.m[0][2], fz = -head.m[2][2];
+        const double n = std::sqrt(fx * fx + fz * fz) + 1e-9;
+        fx /= n, fz /= n;
+        const double rx = -fz, rz = fx;
+        double best = 0;
+        bool found = false;
+        for (const auto &[i, p] : g_spin.base) {
+            const auto s = g_screens.find(i);
+            if (s == g_screens.end() || !s->second.visible) continue;
+            const Mat q = Turned(p, g_spin.to, g_spin.cx, g_spin.cz);
+            const double dx = q.m[0][3] - head.m[0][3], dz = q.m[2][3] - head.m[2][3];
+            double a = std::atan2(dx * rx + dz * rz, dx * fx + dz * fz) * 180 / M_PI;
+            if (!next) a = -a;
+            if (a <= kSpinAhead) a += 360;
+            if (!found || a < best) best = a, found = true;
+        }
+        if (!found || best >= 360 - kSpinAhead) {
+            if (!g_spin.on) g_spin.base.clear();
+            return (void)std::snprintf(reply, size, "ok 0 (no other panel)");
+        }
+        if (best > 180) best -= 360;  // the short way round
+        turn = next ? best : -best;
+    } else {
+        char *end;
+        turn = std::strtod(arg, &end);
+        if (end == arg || *end) return (void)std::snprintf(reply, size, "error spin next|prev|<degrees>");
+    }
+    g_spin.to += turn * M_PI / 180;
+    g_spin.start = Clock::now();
+    g_spin.on = true;
+    SendPointer("recenter");  // the 3D mouse's pointer stays in front of you, on what comes there
+    std::snprintf(reply, size, "ok %.1f", turn);
+}
+
 uint32_t LinuxButton(uint32_t vrButton) {
     switch (vrButton) {
         case vr::VRMouseButton_Right: return BTN_RIGHT;
@@ -1514,6 +1635,81 @@ void ReleaseAwayBy(vr::TrackedDeviceIndex_t dev, uint32_t vrButton, void (*handl
     if (g_press.buttons && dev == g_press.device) ReleaseAway(LinuxButton(vrButton), handle, data);
 }
 
+// Where a laser meets a panel's surface, in the panel's u (metres along it from the centre,
+// along the arc when curved) and v (up). OpenVR curves a screen into a cylinder toward its
+// front, centred `curve` metres in front of it (see OnSurface).
+bool RayOnSurface(const Screen &s, const Mat &p, const Mat &laser, double *u, double *v) {
+    const Mat inv = Inverse(p);
+    const double o[3] = {inv.m[0][0] * laser.m[0][3] + inv.m[0][1] * laser.m[1][3] + inv.m[0][2] * laser.m[2][3] + inv.m[0][3],
+                         inv.m[1][0] * laser.m[0][3] + inv.m[1][1] * laser.m[1][3] + inv.m[1][2] * laser.m[2][3] + inv.m[1][3],
+                         inv.m[2][0] * laser.m[0][3] + inv.m[2][1] * laser.m[1][3] + inv.m[2][2] * laser.m[2][3] + inv.m[2][3]};
+    double d[3];
+    for (int i = 0; i < 3; ++i) d[i] = -(inv.m[i][0] * laser.m[0][2] + inv.m[i][1] * laser.m[1][2] + inv.m[i][2] * laser.m[2][2]);
+    if (s.curve <= 0) {
+        if (std::fabs(d[2]) < 1e-6) return false;
+        const double t = -o[2] / d[2];
+        if (t <= 0) return false;
+        *u = o[0] + d[0] * t, *v = o[1] + d[1] * t;
+        return true;
+    }
+    // x^2 + (z - r)^2 = r^2, on the screen's side of the axis (z < r).
+    const double r = s.curve, oz = o[2] - r;
+    const double a = d[0] * d[0] + d[2] * d[2], b = 2 * (o[0] * d[0] + oz * d[2]), c = o[0] * o[0] + oz * oz - r * r;
+    const double disc = b * b - 4 * a * c;
+    if (a < 1e-9 || disc < 0) return false;
+    for (double t : {(-b - std::sqrt(disc)) / (2 * a), (-b + std::sqrt(disc)) / (2 * a)}) {
+        const double x = o[0] + d[0] * t, z = oz + d[2] * t;
+        if (t <= 0 || z >= 0) continue;
+        *u = r * std::atan2(x, -z), *v = o[1] + d[1] * t;
+        return true;
+    }
+    return false;
+}
+
+// Where the mode leaves the controllers to a VR game (see the top): a hand controller
+// pointing at a panel, its controls, or a floating window's popups keeps that panel's laser
+// on (UpdateLasers) until kAimLinger ticks after it points away, like SteamVR's own floating
+// windows. Leaving takes a wider margin than arriving, and a drag or a held button keeps it
+// on. The keyboard is one overlay, so SteamVR's own intersection test does there.
+void UpdateAim() {
+    if (LasersByMode()) return;
+    std::vector<Mat> lasers;
+    for (vr::TrackedDeviceIndex_t i = 1; i < vr::k_unMaxTrackedDeviceCount; ++i) {
+        Mat d;
+        if (IsHandController(i) && LaserPose(i, &d)) lasers.push_back(d);
+    }
+    for (auto &[index, s] : g_screens) {
+        Mat p;
+        if (!s.visible || !ScreenPose(s, &p)) continue;
+        if (s.drag != Drag::None || (g_press.buttons && g_press.screen == index)) {
+            s.aimUntil = g_tick + kAimLinger;
+            continue;
+        }
+        const double m = s.grip * (g_tick < s.aimUntil ? 2.0 : 0.25), h = s.heightMetres();
+        // The panel and its controls: the bar row under it, the resize tab off its corner.
+        const double halfW = std::max(s.metres / 2 + s.grip, s.chrome / 2 + s.chrome * 0.12 + s.grip * 2) + m;
+        const double top = h / 2 + m, bottom = std::min(BarY(s) - s.grip, -(h / 2 + s.grip)) - m;
+        for (const Mat &l : lasers) {
+            double u, v;
+            if (!RayOnSurface(s, p, l, &u, &v)) continue;
+            bool on = std::fabs(u) <= halfW && v <= top && v >= bottom;
+            for (const auto &[k, sub] : s.subs) {
+                if (on || s.cropW <= 0) break;
+                const double su = (sub.x + sub.w / 2.0 - (s.cropX + s.cropW / 2.0)) * s.mpp;
+                const double sv = -(sub.y + sub.h / 2.0 - (s.cropY + s.cropH / 2.0)) * s.mpp;
+                on = std::fabs(u - su) <= sub.w * s.mpp / 2 + m && std::fabs(v - sv) <= sub.h * s.mpp / 2 + m;
+            }
+            if (on) {
+                s.aimUntil = g_tick + kAimLinger;
+                break;
+            }
+        }
+    }
+    if (keyboard::Shown())
+        for (const Mat &l : lasers)
+            if (keyboard::Aimed(l)) g_keyboardAimUntil = g_tick + kAimLinger;
+}
+
 const char *LasersName() {
     switch (g_lasers) {
         case Lasers::Always: return "always";
@@ -2071,10 +2267,19 @@ void ft_vr_poll(void (*handle)(const struct ft_event *, void *), void *data) {
         handle(&e, data);
     }
     ++g_tick;
+    UpdateSpin();
+    if (g_spin.front >= 0) {
+        ft_event e{};
+        e.type = FT_FRONT;
+        e.screen = g_spin.front;
+        g_spin.front = -1;
+        handle(&e, data);
+    }
     UpdateGame();
     UpdateArrange();
     UpdateVisibility();
     UpdateAttention();
+    UpdateAim();
     UpdateLasers();
     UpdateControls();
     UpdateGuides();
@@ -2101,7 +2306,7 @@ bool ft_vr_keyboard_show(int index) {
     const double fx = -head.m[0][2], fz = -head.m[2][2], n = std::sqrt(fx * fx + fz * fz) + 1e-9;
     const double at[3] = {head.m[0][3] + fx / n * kKeyboardAhead, head.m[1][3] - kKeyboardBelow,
                           head.m[2][3] + fz / n * kKeyboardAhead};
-    keyboard::SetLasers(g_lasers == Lasers::Always || (g_lasers == Lasers::OutsideGames && !g_gameRunning));
+    keyboard::SetLasers(LasersByMode());
     g_steamInFront = SteamInFront();
     if (g_steamInFront) {
         g_asidePose = FacingPose(at, head);
@@ -2146,6 +2351,8 @@ void ft_vr_keyboard_hide(void) {
 //                             ~100 ms (it landed on something else), KWin gets it anyway
 //   state         -> "ok <mode> <manual 0|1> <wrist deg> <gesture hand> <gesture deg>
 //                     <controllers> <game running 0|1> <ingames>"
+//   spin next|prev|<degrees>  turn every panel in the room about your head (see the lazy
+//                             susan) -> "ok <degrees turned>"
 //   cutouts on|off|state      hand cutouts (see handcut.h) -> "ok <on|off> <ready|idle|unavailable>
 //                             <last composite ms> ms, predict <on|off> lead <ms> ms"
 //   cutouts predict on|off    move the hands ahead along their velocity (on by default)
@@ -2183,6 +2390,7 @@ void ft_vr_command(const char *cmd, char *reply, int size) {
         Screen *s = Find(n);
         if (!s) return (void)std::snprintf(reply, size, "error no screen %d", n);
         EndDrag(*s);
+        g_spin.base.erase(n - 1);
         SetAbsolute(*s, PanelPose(x, y, z, yaw, pitch, roll));
         std::snprintf(reply, size, "ok");
     } else if (std::sscanf(cmd, "width %d %lf", &n, &w) == 2) {
@@ -2349,6 +2557,7 @@ void ft_vr_command(const char *cmd, char *reply, int size) {
         Mat m{};
         for (int k = 0; k < 12; ++k) m.m[k / 4][k % 4] = r[k];
         EndDrag(*s);
+        g_spin.base.erase(n - 1);
         SetAbsolute(*s, m);
         std::snprintf(reply, size, "ok");
     } else if (int k0; std::sscanf(cmd, "sub %d %d %d %d %d %d", &n, &k0, &x0, &y0, &w0, &h0) == 6 ||
@@ -2376,6 +2585,8 @@ void ft_vr_command(const char *cmd, char *reply, int size) {
         if ((g_press.buttons & ButtonBit(BTN_LEFT)) && g_press.device != kNone && !IsHandController(g_press.device))
             g_press.upAt = g_tick + 9;
         std::snprintf(reply, size, "ok");
+    } else if (std::sscanf(cmd, "spin %15s", word) == 1) {
+        SpinCommand(word, reply, size);
     } else if (std::strncmp(cmd, "state", 5) == 0) {
         std::snprintf(reply, size, "ok %s %d %.0f %s %.0f %s %d %s", ModeName(), g_manual ? 1 : 0, g_wristAngle,
                       g_gestureHand.c_str(), g_gestureAngle, LasersName(), g_gameRunning ? 1 : 0,

screens/vr.h

@@ -17,7 +17,8 @@ struct ft_dmabuf {
     int fd[4];
 };
 
-enum ft_event_type { FT_MOTION, FT_BUTTON, FT_SCROLL, FT_LEAVE, FT_QUIT, FT_KEY, FT_KEYBOARD_CLOSED };
+// FT_FRONT: a spin (the lazy susan) brought panel `screen` to straight ahead: typing goes there.
+enum ft_event_type { FT_MOTION, FT_BUTTON, FT_SCROLL, FT_LEAVE, FT_QUIT, FT_KEY, FT_KEYBOARD_CLOSED, FT_FRONT };
 
 struct ft_event {
     enum ft_event_type type;