Brian
Wed Jul 09 20:49:48 CDT 2003
"alex." <ahtremblay@videotron.ca> wrote in message
news:05d001c34667$6e2d8a80$a301280a@phx.gbl...
> Hi Brian,
>
> Okay, so what can I do with my filter driver onced I
> installed it? I need to "gain access" to the data of other
> drivers because I need to add a "sticky" bitmap to the
> screen. I was thinking of mapping the bitmap to the screen
> along with the rest of the screen info.
What do you mean by 'other drivers'? The filter driver would see all drawing
commands, and would have to pass the commands to the real display driver (or
nothing would ever be displayed). If you want to insert a command to draw a
bitmap, that is pretty straightforward to implement.
> Note; that bitmap will have to stay visible, even when a
> third party application is using directx.
This would be a bit harder, but should also be possible; however, if an
application is using DirectDraw (2D), then the frame buffer will be mapped into
the process' address space, allowing the application do draw whatever it wants
into the frame buffer - possibly overwriting your bitmap. On the bright side,
applications that use the DirectDraw APIs have been diminishing steadily for the
last several years, so that probably won't be much of a problem for you
> Can I gain access to this data with filter driver and can
> I modify it?
Sure
-Brian
Brian Catlin, Sannas Consulting 310-798-8930
Windows Network, Video, WDM Device Driver Training & Consulting
See WWW.AZIUS.COM for courses and scheduling
> thanks. alex
>
> >-----Original Message-----
> >"alex_ht" <ahtremblay@videotron.ca> wrote in message
> >news:019001c34248$e987b750$a101280a@phx.gbl...
> >> Hi, I'm in bug trouble. I need to know if windows will
> >> allow me to install a filter driver between the Graphic
> >> engine (GDI) and the Graphic drivers?
> >
> >Yes, it is possible; I've done it. You will have to
> substitute your "filter
> >driver" for the real driver, and then load the real
> driver from within your
> >filter driver, using EngLoadImage
> >
> >> I need to filter
> >> some packets. Any information will be appreciated. Thank
> >> you.
> >
> >The graphics drivers are not like any other driver type;
> they do not implement
> >packet-driven I/O (IRPs). Graphics drivers are actually
> two drivers, a
> >"display" driver, which handles all drawing operations,
> and a "miniport" which
> >handles non-drawing operations (such as mode changes,
> cursor positioning, color
> >table setting, etc.)
> >
> > -Brian
> >
> >Brian Catlin, Sannas Consulting 310-798-8930
> >Windows Network, Video, WDM Device Driver Training &
> Consulting
> >See WWW.AZIUS.COM for courses and scheduling
> >
> >
> >.
> >