joule-moq-web room: draw only what changed, and send a key at once #585

Merged

dcharlot merged 1 commit from room/draw-on-new-frame into main 2026-11-02 19:49:35 -05:00

Conversation 0 Commits 1 Files changed 7 +316 -15

2026-11-02

Transaction Science

joule-moq-web room: draw only what changed, and send a key at once ...

The room's compositor redrew every tile on a fixed timer, whether or not a new
frame had arrived, on a canvas asking for software rendering so that a test hook
could read it back. A still room spent draws at the full rate, and a frame waited
up to a whole period for the next tick.

A tile is now drawn when its video has a new frame, at the next display refresh,
with whatever lies over it; the whole canvas only after a re-layout. Simply drawing
the canvas on every new frame would be worse for a large grid, whose unsynchronised
sources would repaint all of it at every refresh. `stats()` reports what drawing
spent: counts a test can hold, since a busy host can't flake them, and the latency
from a frame's arrival to its drawing, which is reported and not held.

The room's log and timeline no longer grow without bound in the DOM.

Remote control held every action for the next refresh. A pointer moving is many
actions a refresh, and that suits it; a key, a button or a wheel is one thing that
happened, and now goes at once with the moves before it. Coalesced moves also kept
the pointer's oldest place in a refresh, because the batch held a copy of the move
that later ones updated in vain. They now keep the latest.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

d3507ca658

• View at this point in history

2026-11-02 13:45:42 -05:00