Vista - June CTP - transparent windows rendered in hardware?

Are transparent windows rendered in hardware? I remember setting
'UsesPerPixelOpacity' to true caused the whole window to be rendered
in software, now I'm wondering if that's still true with
'AllowsTransparency'...?

Florian

I have tested the sample app from here
http://laurenlavoie.com/avalon/162
using Perforator and it seems that the window is rendered in hardware.
--
Valentin Iliescu [MVP - Client Application Development]


"Florian Kruesch" wrote:

> Are transparent windows rendered in hardware? I remember setting
> 'UsesPerPixelOpacity' to true caused the whole window to be rendered
> in software, now I'm wondering if that's still true with
> 'AllowsTransparency'...?
>
> Florian
>

viliescu wrote:
> I have tested the sample app from here
> http://laurenlavoie.com/avalon/162
> using Perforator and it seems that the window is rendered in hardware.

that's what I wanted to hear
thx!

On Mon, 3 Jul 2006 19:18:02 -0700, =?Utf-8?B?dmlsaWVzY3U=?=
<viliescu@discussions.microsoft.com> wrote:

>I have tested the sample app from here
>http://laurenlavoie.com/avalon/162
>using Perforator and it seems that the window is rendered in hardware.
>--
>Valentin Iliescu [MVP - Client Application Development]

The article indicates that a layered window is used. I've been trying
to determine if there is a way that hardware accelerated 3D rendering
(via Direct3D or OpenGL) can render transparently to the desktop in
Vista. So far I've been unsuccessful in making this work. There is
UpdateLayeredWindow, but it requires that the rendered data be read
back into system memory first. If the sample app really is fully
hardware accelerated, how does it work? Is it using an uncodumented
API?

Chris

I dont know how they did it, but I wouldn't assume it's not being read back
into system memory (at least on XP). As long as the CPU isn't doing all the
Visual rendering I would still consider it HW accelerated and propbably only
slighly slower than a non-per pixel alpha window.

"Chris Hill" wrote:

> On Mon, 3 Jul 2006 19:18:02 -0700, =?Utf-8?B?dmlsaWVzY3U=?=
> <viliescu@discussions.microsoft.com> wrote:
>
> >I have tested the sample app from here
> >http://laurenlavoie.com/avalon/162
> >using Perforator and it seems that the window is rendered in hardware.
> >--
> >Valentin Iliescu [MVP - Client Application Development]
>
> The article indicates that a layered window is used. I've been trying
> to determine if there is a way that hardware accelerated 3D rendering
> (via Direct3D or OpenGL) can render transparently to the desktop in
> Vista. So far I've been unsuccessful in making this work. There is
> UpdateLayeredWindow, but it requires that the rendered data be read
> back into system memory first. If the sample app really is fully
> hardware accelerated, how does it work? Is it using an uncodumented
> API?
>
> Chris
>