Re: Fix Using DDraw to Access the Desktop

[Alexandre Julliard]

Robert Shearman  writes:
> Previously, using ddraw to write to a small area of the desktop (or
> even none at all) would cause the screen to go black because the
> contents of the screen wasn't copied to the surface before the surface
> was copied back to the screen. This patch fixes that.

Of course it's still corrupting the screen, it's just less obvious...

Fix Using DDraw to Access the Desktop

[Robert Shearman]

Alexandre Julliard wrote:
> Robert Shearman  writes:
> > Previously, using ddraw to write to a small area of the desktop (or
> > even none at all) would cause the screen to go black because the
> > contents of the screen wasn't copied to the surface before the surface
> > was copied back to the screen. This patch fixes that.
>
> Of course it's still corrupting the screen, it's just less obvious...

I'm pretty sure Windows NT doesn't allow you to have direct access to 
the video memory so surely Windows must be doing it like this too?
How do you suggest to fix the problem?

Fix Using DDraw to Access the Desktop

[Lionel Ulmer]

On Wed, Jul 27, 2005 at 04:33:29PM +0100, Robert Shearman wrote:
> I'm pretty sure Windows NT doesn't allow you to have direct access to 
> the video memory so surely Windows must be doing it like this too?
> How do you suggest to fix the problem?

The only way I could think of would be to lock the X display between the
call to the lock to the time of the unlock (a bit what WMs like FVMW do when
a window is resized).

Lionel

Fix Using DDraw to Access the Desktop

[Alexandre Julliard]

Robert Shearman  writes:
> I'm pretty sure Windows NT doesn't allow you to have direct access to
> the video memory so surely Windows must be doing it like this too?
> How do you suggest to fix the problem?

Windows will certainly let you access the video memory, but since we
can't do that I'm afraid there is no good solution. We could grab the
server but that probably causes more problems than it solves.

Maybe we should simply not try to update the root window when no clip
list is set, since it can't work right anyway. Apps that really need
that feature could always be run in desktop mode.