bug#460: 23.0.60; x-display-color-cells returns 20 on w32 remote desktop

[jpw@pobox.com (John Paul Wallington)]

Jason Rumney <jasonr@gnu.org> wrote:

> John Paul Wallington wrote:
> 
> > When I run Emacs on my Windows machine and look at it with Remote
> > Desktop Connection on my Mac the modeline faces are black and white.
> > This is because the `mode-line' face is defined as inverse-video for
> > displays with less than 88 colors, and `x-display-color-cells' returns
> > 20 when using RDC.
> 
> Are you sure that is not correct? One of the bandwidth saving techniques
> that RDP uses is to reduce the number of colors.

I see.  The link here at home is fast enough to make using RDC perfectly
usable with lots of colors.  Same at work where we have machines miles
away in co-location.  Using RDC, Windows Display Properties says that
the Color Quality is "Medium (15 bit)" - Emacs itself gives 783 for
(length (defined-colors)) and doing M-x list-colors-display shows those
colours fine; they're distinguishable and undithered.  When browsing the
Web or watching a video clip the 15 bit RDC display is not quite as good
as the 24 bit display of the console, but uses a high number of colours.
Every desktop icon on that machine bar one is a High Color image.  However,
I've never ran RDC in a heavily bandwidth-constrained situation.