Path: utzoo!utgpu!watmath!att!ucbvax!tut.cis.ohio-state.edu!bloom-beacon!EXPO.LCS.MIT.EDU!rws
From: rws@EXPO.LCS.MIT.EDU
Newsgroups: comp.windows.x
Subject: Re: Color to Grayscale mapping
Message-ID: <8908071428.AA02515@expire.lcs.mit.edu>
Date: 7 Aug 89 14:28:00 GMT
References: <5631@b11.ingr.com>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
Lines: 24


    I have a question about how color allocation is done on a StaticGray
    color display.

You get the "closest RGB values provided by the hardware".  That's all the
protocol says, for better or for worse.

    I remember reading in something that R G and B should all be set to
    the same value by the client because it cannot be sure which one of these
    three that the server will use as an intensity.

This is only when storing (StoreColors) into a GrayScale map.

    finds the color that minimizes the following ...
    really happens? Yes!! Hey this is it but not documented ANYWHERE

Because it's not part of the protocol specification.  (Also, you missed an
important part of the implementation, which is that ResolveColor gets called,
and it can transform the RGB values.  For example, in the server I'm typing at,
it transforms to a gray value according to the 30/59/11 percentages.  Since the
GrayScale map happens to have been initialized similarly, the FindBestPixel
code pretty much ends up actually looking for equality.  Since ResolveColor can
vary with each ddx, it's kinda hard to provide a single description of what
the sample server chooses to do for this implementation-dependent detail.)