[Bug 34889] New: Drawing to device context outside message loop does not update window

http://bugs.winehq.org/show_bug.cgi?id=34889

Bug #: 34889
           Summary: Drawing to device context outside message loop does
                    not update window
           Product: Wine
           Version: 1.7.4
          Platform: x86-64
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: winex11.drv
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]
    Classification: Unclassified

Created attachment 46495
  --> http://bugs.winehq.org/attachment.cgi?id=46495
Source code demonstrating the issue.

When drawing to a window DC outside the message loop, the window does not
update (see attachment).

On Windows: There is a flickering rectangle in the upper corner of the window
On Wine: The rectangle is not affected until a message is posted from the
system

Example compiled and tested with g++ 4.7.1 TDM-GCC 64 bit on Windows 7 64 bit.
Compiler command:

g++ test.cpp -mwindows
a.exe

[Bug 34889] Drawing to device context outside message loop does not update window

http://bugs.winehq.org/show_bug.cgi?id=34889

[e-mail] changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |testcase

[Bug 34889] Drawing to device context outside message loop does not update window

http://bugs.winehq.org/show_bug.cgi?id=34889

[e-mail] changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |[e-mail]

[Bug 34889] Drawing to device context outside message loop does not update window

http://bugs.winehq.org/show_bug.cgi?id=34889

--- Comment #1 from Alexandre Julliard  2013-11-10 14:17:58 CST ---
Is there an actual application that has this problem?

[Bug 34889] Drawing to device context outside message loop does not update window

http://bugs.winehq.org/show_bug.cgi?id=34889

--- Comment #2 from [e-mail] 2013-11-12 01:32:21 CST ---
(In reply to comment #1)
> Is there an actual application that has this problem?

I use this technique because the way through InvalidateRect -> UpdateWindow ->
WM_PAINT is much slower than just drawing directly. It also separates control
from display in a natural way.

A more complete scenario is

1. Create a window
 2. Get context of the window
 3. Start message loop. In this state, drawing is done through WM_PAINT
 4. User presses a "Start" button. A new program thread is started that checks
for a stop flag. If it is false, it issues commands that update the contents of
the window regularly without user interaction (spin OpenGL triangle if you
like). Meanwhile, the message loop checks for user input. Drawing may be issued
by WM_PAINT as well if the rendering is slow (or paused in case of a clock) but
drawing is fast.
 5. When user presses a "Stop" button the stop flag raises causing the
rendering thread to exit. Drawing is again issued by WM_PAINT

The reason of posting this bug is that I suspect limitations in X. For example,
GTK cannot do this.

[Bug 34889] Drawing to device context outside message loop does not update window

http://bugs.winehq.org/show_bug.cgi?id=34889

--- Comment #3 from Alexandre Julliard  2013-11-12 02:41:50 CST ---
That's not X limitations. The client-side rendering is flushed when the app
processes messages. It would be possible to add extra flushing, but that would
hurt performance for properly behaved apps, so I'm not going to do this unless
there's a demonstrated need for it.

[Bug 34889] Drawing to device context outside message loop does not update window

http://bugs.winehq.org/show_bug.cgi?id=34889

--- Comment #4 from [e-mail] 2013-11-12 10:52:08 CST ---
Perhaps I should GdiFlush()

[Bug 34889] Drawing to device context outside message loop does not update window

http://bugs.winehq.org/show_bug.cgi?id=34889

Jerome Leclanche  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |WONTFIX

--- Comment #5 from Jerome Leclanche  ---
Per AJ, WONTFIX.

[Bug 34889] Drawing to device context outside message loop does not update window

https://bugs.winehq.org/show_bug.cgi?id=34889

Austin English  changed:

What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |CLOSED

--- Comment #6 from Austin English  ---
Closing.