Re: Windows XP display driver brush color question
- From: "Ivan Brugiolo [MSFT]" <ivanbrug@xxxxxxxxxxxxxxxxxxxx>
- Date: Thu, 10 May 2007 10:54:11 -0700
Yes, that's correct as far as the problem was described and understood.
If you could post a stack of the place where that happens,
and the application generating that, I might be able to cross check.
--
--
This posting is provided "AS IS" with no warranties, and confers no rights.
Use of any included script samples are subject to the terms specified at
http://www.microsoft.com/info/cpyright.htm
"Mr Hat" <MrHat@xxxxxxxxxxxxx> wrote in message
news:05A0D449-ABC8-42F0-85F5-5F94E95581DD@xxxxxxxxxxxxxxxx
I just want to verify that I understand correctly:
Despite the "extra" information in the upper byte returned from
BRUSHOBJ_ulGetBrushColor, the RGB data returned contains the correct color
information. The solution to my problem is to ignore the upper byte
returned
(after checking for a return value of -1).
"Ivan Brugiolo [MSFT]" wrote:
In certain parts of NtGdi, the high byte of a COLOREF
is reused for storing a few private bits for Image Color Management.
That's why a `solid` color brush cannot have alpha, and, the closest
approximation of that is a 32bpp 1x1 bitmap-based brush with alpha,
to be used in StretchBlt and BitBlt operations.
--
--
This posting is provided "AS IS" with no warranties, and confers no
rights.
Use of any included script samples are subject to the terms specified at
http://www.microsoft.com/info/cpyright.htm
"Mr Hat" <MrHat@xxxxxxxxxxxxx> wrote in message
news:0DBA48D2-8D3A-480B-B737-56995AD6C27D@xxxxxxxxxxxxxxxx
The ddk states that BRUSHOBJ_ulGetBrushColor returns either an RGB
value
or
-1 if the brush is not solid. When our driver is running in an 8bit
display
mode with no palette, we sometimes see bits set in the upper 8 bits of
the
return value. Is this an indication of an invalid color, or is it
correct
for
GDI to return alpha information as part of the RGB data?
Note: Our driver is for a display adapter optimized for grayscale
medical
imaging. The 8bit display mode is used to display grayscale images.
.
- References:
- Re: Windows XP display driver brush color question
- From: Ivan Brugiolo [MSFT]
- Re: Windows XP display driver brush color question
- Prev by Date: Re: how to write on a vhd
- Next by Date: Re: Physical Address Problem... Help me.
- Previous by thread: Re: Windows XP display driver brush color question
- Index(es):
Relevant Pages
|
