ft-screens gave KWin a frame callback for every committed screen on each tick, and the tick
was an 11 ms timer set again after each run, so it slid through the display's frame and came
about 85 times a second at 90 Hz: the desktop repeated a frame several times a second (judder
in scrolling and video), and KWin drew every screen in one burst at a random point of
vrcompositor's frame. Hidden screens got the same 90 Hz unless Frametop was paused for a game.
- Ticks run on a timerfd at absolute times, once per display frame, 1 ms after the vsync
(IVRSystem::GetTimeSinceLastVsync and the HMD's display frequency, read once a second), so
KWin gets its callbacks early in the frame. Measured with --no-vr: 91 wakeups a second
instead of about 85. On the Frame the vsync times SteamVR reports lie on a 90 Hz grid.
- Each screen's callbacks come at a rate for how much of it you see (vr.cpp,
UpdateAttention): every frame while focused (within 12 degrees of where your head points,
a laser or the mouse on it in the last 1.5 s, carried, or typed on), 15 a second for the
rest of what you see (within 60 degrees), and 1 a second when hidden, behind you, or
paused. Levels rise at once and fall after 1.5 s (focused) or 0.5 s (in view). KWin draws
a screen only after its callback and its apps wait for theirs, so this throttles the apps
too. A screen where nothing changes costs nothing at any rate, as before.
- A video in view keeps every frame: 8 commits in a row that each redraw 6% or more of the
screen, at 10 a second or more, count as one (from the surface's buffer damage).
- "rates F V H" / --rates set the three rates (default 0 15 1, 0 = every frame), "rates?"
shows them and each screen's level, "watch S" gives everything full rate for S seconds for
a remote viewer (vnc-bridge.sh renews it), and "phase MS" moves the ticks for tuning.
- ft-screens' main thread runs at nice -5 after the session starts: SteamOS allows down to
-8 once the soft RLIMIT_NICE is raised, and KWin waits on these ticks. It had spent nearly
3 times as long waiting to run as running.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Fixes#7: SteamVR's keyboard never came up for the desktop's apps, and
opening it for our panels doesn't work well on the Frame (it's Steam's own
panel, mounted in the dashboard's scene, it follows the laser between
panels, and it takes the controllers over to SteamVR's laser).
- KWin starts input/ft-textinput as the desktop's input method. It tells
the input relay when a text field gains or loses focus, and the relay
asks ft-screens to open or close the keyboard. The session drops the
QT_IM_MODULE=xim and GTK_IM_MODULE=xim that the gamescope session sets,
or Qt and GTK apps never report text fields.
- The keyboard is ft-screens' own panel (screens/keyboard.cpp): a US laptop
layout, typed with a controller's laser or the 3D mouse. It opens 0.7 m
in front of you, below your eyes and facing you. It has a grab bar to
move it, a Close key, latching Shift, Ctrl and Alt, and repeat on a held
key. It's drawn into shared DMA-BUFs, so it doesn't flicker. Its keys
reach the focused screen as key presses, so every app takes them.
- It steps aside while the Steam menu or Steam's own keyboard is up and
comes back after. A layout reset closes it, and it doesn't open without
a head pose.
- Frametop Input Settings has a Keyboard page: open it for every text
field, only while no keyboard is connected (the default), only from a
mapped button (the new Open/close keyboard action, for mice and
controllers), or never. A switch keeps it open until you close it.
- The pointer helper treats every frametop.* overlay as a real panel. The
keyboard's shared texture reports 0x0 like SteamVR's scene-graph
controls, and the helper had given it their wide catch radius.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Where frame-hands tracks a hand between an eye and a screen, that eye sees the
room through the screen. handcut.cpp draws the screen's buffer side by side
(one half per eye) with the hands cut out, only while a hand is in front of it.
The cutouts command turns it on or off. ft-handtest tries it on a test panel.
Not yet tested in the headset.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Several KDE Plasma screens floating in SteamVR, each a real monitor of any
resolution and shape, shown by our own compositor (ft-screens), with a
layout, wrist pinning, and visibility modes; a Bluetooth mouse that drives
all of SteamVR as a room-anchored 3D pointer (input relay, ft-pointer
helper, ft_pointer SteamVR driver); two settings apps; and Bluetooth LE
fixes. Installs on the headset with ./install.sh.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
