tools.book: serve a busy-only iCalendar feed on cal.lassul.us
For when.lassul.us (timeful) to show lass's availability without event
details, at https://cal.lassul.us/busy/<token>.ics.
With --busy-token-file, GET /busy/<token>.ics returns the busy time book
itself uses for free slots (CalDAV.busy plus held requests), so the feed
and the booking page agree on what blocks time: recurrences expanded,
all-day events from local midnight, TRANSPARENT and CANCELLED events
left out, TENTATIVE events (own ones and pending booking requests) kept
as busy, since book holds those slots too.
Intervals are merged so overlapping events cannot be counted, and each
VEVENT carries only DTSTART/DTEND in UTC, DTSTAMP (required by RFC
5545), SUMMARY "Busy", TRANSP OPAQUE and a UID hashed from its times.
The window runs from 7 days back to 90 days ahead: book's own 28 day
horizon is too short for polls planned weeks ahead, and the past week
keeps polls that are still open showing sensible data.
The feed is generated per request, so it is as fresh as the calendar;
an unreadable calendar gives 503, never an empty feed. Any other path
under /busy/ gives 404; the token is compared in constant time.
configs/book.nix: the token comes from the prompt-less vars generator
busy-feed and reaches book as a systemd credential, so it never lands in
the Nix store; nginx proxies all of cal.lassul.us/busy/ to book.
book.lassul.us returns 404 for /busy/ so the feed has a single URL.
tools.hermes-voice: native Android app answers the headset button
The Android app holds the call itself instead of opening the page in a
Custom Tab: hold the headset's voice button (HFP AT+BVRA=1 starts
VOICE_COMMAND), talk, short press to hang up, all with the phone locked
and without looking at it.
- VoiceCall: the page's Call in Java over WebRTC (webrtc-sdk/android):
delegation to Hermes, voice approvals, end_call, idle hang-up.
- CallService: a self-managed Telecom call in the foreground, so the
audio goes to the headset and its hang-up (AT+CHUP) ends the call; a
tone says it listens.
- Screens: the current conversation with Call / Hang up, the list of
conversations, and the settings (app token, permissions).
- hermes-voice accepts the app's own token (--app-token-file, clan var
hermes-voice-app on coaxmetal); assist.lassul.us/app/ passes it
through without the web login.
- The page keeps Talk / Hang up in view: only the transcript scrolls.
assetlinks.json, the TWA and the page's ?listen go away with the
Custom Tab.
tools.realwallpaper: real colour imagery on the day side
The day side now shows what the geostationary satellites see, like
zoom.earth, instead of the base map under white clouds synthesised from
infrared:
- Europe/Africa/Atlantic: MTG (Meteosat-12) rgb_truecolour from EUMETSAT.
rgb_geocolour looks the same by day but renders ~4x slower on the
server and timed out (502) for full 2048 px tiles.
- Americas/Pacific: GOES-East and GOES-West GeoColor from GIBS.
- Asia/Australia: GIBS has no Himawari colour product. Himawari band 3
(red, 10 min) is turned into white cloud over the base map, with the
cloud opacity being the reflectance beyond the ground's own albedo.
The daily VIIRS true colour mosaics were the alternative, but their
clouds are up to a day old, have swath seams of different times and
would not match the IR clouds next to them.
Each source is weighted by how well its satellite sees the point: full
trust up to 62° view zenith, none from 78° (the limb is smeared), and
the more nadir satellite wins in overlaps with cos^8 of the zenith
angle, so seams are soft. Trust also needs the sun not to be in front
of the satellite: looking towards a low sun both MTG (mornings over the
Indian Ocean) and Himawari (evenings) are washed out to a pale band
with straight edges, while a long path with the sun behind the
satellite is fine (Berlin at winter noon). A plain path-length limit
would have dropped the latter. Near the terminator (cosz < 0.2)
GeoColor fades into its purple night blend, so the live imagery fades
out there and the IR clouds over the base map take over as before.
Where it is shown, the synthetic clouds and so their relief shading and
shadows are scaled down, so the real image is not shaded twice.
All live layers (including the IR clouds) now request an explicit TIME,
the render time floored to 10 min: without TIME GIBS served tiles of
one layer from different frames (sun glint cut at a tile edge), and it
makes --time render the imagery of that time, not only the sun. The
TIME is capped at the newest frame the server lists (GIBS
DescribeDomains, EUMETSAT per-layer capabilities), since GIBS answers
an unpublished time with an empty image and EUMETSAT with an error;
MTG true colour stops producing frames while its disk is dark.
GIBS also now and then answers with an empty 1 kB image for a frame it
has (the same request succeeds when repeated), which left a quarter of
the Himawari disk missing, so empty tiles are asked for up to 3 times.