You pull the window bigger and then smaller, but there is serious lag, the window is smaller but the contents inside are still getting bigger and vice verse. There is a disconnect between resizing and redrawing. Also, it flickers white and sometimes stays white.
I’ve built my app yesterday with develop branch and was experiecing exactly the same issue. Weirdly it was less the case the more I was doing it.
reuk
January 20, 2026, 12:03pm
4
Thanks for reporting. A fix for this issue has been published:
committed 10:55AM - 20 Jan 26 UTC
258203706cdfc1357effe8cc752672b793cea37d introduced a problem where
live-resize … of a window would cause the window content to flash and slow
down.
The cause of the errant behaviour seems to be that, during resize, many
WM_PAINT messages might be dispatched over the course of a single vblank
interval. Then, each of these paint calls was waiting for the next
vblank interval to display. This additional waiting resulted in
sluggishness, since many frames would have to be presented before the
presentation 'caught up' with the current window size. This also meant
that many consecutive frames were presented with stale window size
information.
The solution added here simply checks whether we're live resizing, and
uses the vblank instead of WM_PAINT to synchronise repaints during the
resize operation.
