VNC viewer ignores -truecolor
Mon Jun 23 15:01:01 2003
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On June 20, 2003 10:25 pm, Fred Ma wrote:
> Grant McDorman wrote:
> > > I am using TightVNC connect from sunbox to
> > > sunbox. The remote VNC server is 24-bit
> > > true color, while the local machine's
> > > display has 6 visuals, one of which is
> > > 24-bit true color. When I try to start
> > > the vncviewer with -truecolor, it always
> > > says that it is using 8-bit pseudocolor.
> Hi, Grant,
> Actually, your comment sent me off on some more
> sleuthing. The problems seems to be that -owncmap
> is being specified (I forgot that I had vncviewer
> aliased to always specify -owncmap). If I specify
> -truecolor without -owncmap, the viewer uses a true
> color visual of depth 8. Funny, but I still get
> flashing colors when moving the mouse pointer in
> and out of the viewer.
Colourmap flashing occurs when the hardware colourmap needs to be reloaded. In
your case, presumably the hardware cannot display TrueColour and PseudoColour
(8-bit colour-mapped) simultaneously. Some hardware can (such as my Creator
3D); most can't.
> The illuminating thing is that if I specify -truecolor
> and '-depth 24', the viewer complains that it can't
> find a matching visual. It uses "default colormap" and
> translates from BGR233.
Yep, you don't have a 24-bit TrueColour visual.
> At least
> with the default colormap, I don't get messed up colors
> when I put the viewer in fullscreen (it seems that the
> fullscreen uses the nonprivate color map when the
> viewer is started with -owncmap!).
Sounds like a bug.
> The reason for not finding a true color visual of
> depth 24 is obvious when I reexamine the xdpyinfo:
> visual id: 0x26
> class: TrueColor
> depth: 8 planes
> available colormap entries: 8 per subfield
> red, green, blue masks: 0x7, 0x38, 0xc0
> significant bits in color specification: 8 bits
24 bit truecolour looks like this:
visual id: 0x2c
depth: 24 planes
available colormap entries: 256 per subfield
red, green, blue masks: 0xff, 0xff00, 0xff0000
significant bits in color specification: 8 bits
Grant McDorman <email@example.com>, Sr. Software Design Consultant
Cedara Software Corp. <URL:http://www.cedara.com>
(formerly I.S.G. Technologies Inc.)
Mississauga, Ontario, Canada
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