BitBlt copies from ghost canvas when it is applied to same canvas
Original Reporter info from Mantis: Valdas
-
Reporter name: Valdas Jankūnas
Original Reporter info from Mantis: Valdas
- Reporter name: Valdas Jankūnas
Description:
Run attached test project. There on OnPaint event of TPaintBox:
- right side of canvas is filled with white color (using FillRect),
- left side of canvas is filled (using BitBlt) with copies of left column from previously filled area,
- in last step in right side of canvas (which is filled with FillRect) a horizontal line is drawn.
In Gtk2 as expected (see attached pic): line only in right side.
In Qt is mess (see attached pics):
- immediately after start right side of canvas filled with pixels from my desktop background,
- after refresh line runs across entire canvas.
Seems that in Qt WS BitBlt takes data from some buffer of Canvas :/
Additional information:
FPC v 3.0.0
KDE uses Qt v 5.7.1
Not sure what Qt version test application uses. How to get that info?
Mantis conversion info:
- Mantis ID: 32141
- OS: Kubuntu 17.04
- Build: 55475
- Platform: linux 4.10.0-26-generic
- Version: 1.9 (SVN)
- Fixed in revision: 62870 (#a6e255c4)
- Monitored by: » Valdas (Valdas Jankūnas)