GDI+DWM lag
1,149 views · Published 27 June 2013 · 0:36 · Indexed 29 September 2026
Channel: anothergol · 2013 · Science & Technology
Apparently some Win7/Win8 system suffer from this GDI/DWM problem, as demonstrated here. If the selection in your FL Studio gets its borders disappearing like this, then your system suffers from it too. Surface Pro has it, it most likely has to do with the DWM v1.1, if we could get anyone to listen at Microsoft it could be fixed (unless it's related to caching & "the way it is in order to reduce memory footprint", which may be the case). Vista may not be affected by this. If confirmed, it could indeed be a problem since DWM 1.1. Also with desktop composition off, no problem either (you'll just get some tearing since there is no vsync anymore). But since Win8, you can't switch desktop composition off anymore. (capture on Scott's Win7 desktop, NVIDEA GeForce GTS 240) As for the code it's dead simple, it only involves moving a lasso from inside wm_MouseMove, in which you invalidate either the lasso's old & new rectangle, or a union of both (doesn't matter, it just CAN'T be the full window), & in wm_Paint, erase the background & paint the lasso, using GDI (FillRect/Rectangle or whatever)
