schcom: repaint what changed, and stop rendering frames nobody sees

Browse source

Moving the mouse repainted the whole screen. At 1280x800 that is a
million pixels of desktop fill, every surface re-blitted, and a 4 MB copy
to the framebuffer -- per event. Under emulation the pointer lagged the
mouse by whole seconds, and that was not the emulation's fault: moving a
10x10 cursor does not require touching four megabytes.

Two changes, and the second matters as much as the first.

Damage tracking: one rectangle, unioned from whatever actually changed,
and only those rows are redrawn and copied out. A pointer move damages
where it was and where it is; a commit damages that surface; a client
going away damages what it had. One rectangle rather than a list, because
in practice the changes are a cursor and the window under it, and a list
costs more bookkeeping than it saves.

Draining input: a single mouse movement produces a burst of EV_REL ending
in EV_SYN, and the loop handled one event per poll and repainted. So the
compositor rendered every intermediate position of a cursor that was
never seen at those positions. Both queues are now drained before
anything is painted. handle_input grew a distinct "queue empty" return
for it -- EV_SYN changes nothing but is not the end of the burst, and a
drain that stopped there would leave the rest queued.

Also cuts the loader's resolution prompt from four seconds to one and a
half, on both the BIOS and UEFI paths. Four was mine and it was too long:
it is paid on every unattended boot, and adding four seconds to every
start to offer a menu nobody usually wants makes the common case worse to
serve the rare one.

schcom-test passes, including two overlapping clients and stacking order.
bootcheck 108 [ok].

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

...

This commit is contained in:

Nexoniarz 2026-08-10 05:54:06 +02:00

parent eafdddefbc

commit bf9ac843f7

4 changed files with 130 additions and 37 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

BIN

projects/schcom/schcom

View file

Binary file not shown.