A small always-on-top mpv window renders the local time in a screen
corner. Implementation notes:
- Transparent lavfi canvas (color=...@0.0, --alpha=yes) so the camera
video shows through; no new dependencies. If the compositor can't do
alpha it degrades to a dark backing, still legible.
- Time drawn as an ASS osd-overlay pushed over mpv IPC once a second:
white fill + black outline (\bord), so it reads on both bright (day)
and dark (night) scenes without sampling the picture. Formatting the
text in Go avoids any filtergraph escaping.
- Time computed with time.LoadLocation against a configured IANA zone
(default "Local"), so it's correct regardless of the host clock's zone
and handles DST. A bad zone name fails at startup.
- Managed on the daemon's own context (survives layout switches); the
daemon keeps it positioned and raised above camera tiles. ensureClock
is a no-op when the clock config + resolution are unchanged, so a
reload never disturbs it.
Config: new `clock` section (enabled, timezone, format, corner,
font_size, width, height, margin) with defaults and corner validation.
Documented in README and config.example (shipped enabled, America/Denver,
24-hour w/ seconds). Tests cover corner geometry.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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