A room's chat log was wrapped to the pane width from the first line on
every frame, so a busy room lagged more the longer it stayed open: in
the harness 30,000 lines cost 16.6ms a frame. The wrapped rows now
live with the log and a draw only wraps the lines that arrived since
the last one, starting over when the width changes. The same cache
serves the private-message box, and the room list draws only its
visible page like the other tables. The 30,000-line room now draws in
0.4ms.
Michel de Graaf
6c4e60bb0e