baketnk--frame-yap/docs/evidence/ui-click-flicker-2026-09-24.md

FrameYap click flicker investigation — 2026-09-24

Dated controls-only observations on one user-authorized Frame. This is not headset acceptance or proof that a compositor update will behave identically. No microphone was opened and no text/Enter was delivered. Both checks used the finite --check-controls --mount world mode; clicks were diagnostic only.

What changed

The earlier diagnostic painted pointer counts, action text and controller state onto the panel, causing SetOverlayRaw uploads even for clicks that would not otherwise alter its pixels. Commit b5499ec logs those values to the terminal instead; it keeps the panel static for Record/Cancel/Insert/Enter clicks, while navigation and mount changes still repaint. A subsequent commit, c59c8b1, counts application raw uploads, show/hide calls and OpenVR visibility/focus/image events without adding repaints.

The rendering loop in src/runtime.cpp and src/overlay.cpp is single-threaded: it draws before polling input and processes click actions before the next draw. No separate logic/render thread race was found in this path. That alone does not identify SteamVR's compositor behavior.

Controls-only trials

• Static-canvas build 2026-09-24T173900Z-gb5499ec was built on Frame from a clean snapshot; 11/11 hardware-free ARM64 tests passed. Its native-only archive was checksum-verified and installed; the previous version was retained. The 30-second probe exited normally with 22 pointer downs, 22 ups and 8 action/ mount/recenter hits. The wearer reported that the whole overlay still disappeared on every action click, including clicks that leave the canvas static. This contradicts full raw uploads being the sole cause of the flash.
• Event-counter build 2026-09-24T174700Z-gc59c8b1 was built on Frame from a clean snapshot; 12/12 hardware-free ARM64 tests passed. It was checksum-verified, installed and version-checked. The 30-second probe exited normally with 7 pointer downs, 7 ups and 2 action/mount/recenter hits. From start to finish, application ShowOverlay calls stayed at 1, HideOverlay calls at 0, VREvent_OverlayShown at 1, and VREvent_OverlayHidden at 0. SetOverlayRaw calls rose from 2 initial uploads to 7 during the trial; image-loaded events reached 7 with no image-failed events. Four overlay and four global focus-change notifications were observed, but not on every click; input-focus-captured and gamepad-focus-lost counters stayed at zero. Pointer events occurred without intervening raw uploads or hide/show events. This second probe had no separate contemporaneous headset visibility report.

The second probe did not log hit targets; its five later raw uploads may include tab, mount or placement-note changes and are not a per-action-click count. The log does not establish that SteamVR never briefly occluded the panel: it only shows that the app did not call hide and received no hidden event in that finite trial. The first trial's visual report plus static-click rendering behavior point toward dashboard laser/input compositing rather than a FrameYap repaint race, but the exact compositor cause remains unverified. A persistent GPU texture alone cannot explain or guarantee a fix for flicker observed when no texture is uploaded.

The installed diagnostic version at the end of this investigation was 2026-09-24T174700Z-gc59c8b1 (native-only, external ASR runtime unchanged); an independent controls-only right-X binding trial occurred between these two builds. No session or SSH process was terminated. No further hardware remedy is claimed here.