Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!decwrl!labrea!jade!ucbvax!shark.tek.COM!paulsh
From: paulsh@shark.tek.COM
Newsgroups: comp.windows.x
Subject: Re: GetStaticColormap
Message-ID: <8711032336.AA25730@shark.GWD.TEK>
Date: Tue, 3-Nov-87 18:36:44 EST
Article-I.D.: shark.8711032336.AA25730
Posted: Tue Nov  3 18:36:44 1987
Date-Received: Sat, 7-Nov-87 08:59:39 EST
References: <8711030356.AA06098@xman.sgi.com>
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The ARPA Internet
Lines: 57


> In the porting layer document, pg. 25 a function pScreen->GetStaticColormap
> is described, however there is no GetStaticColormap function in the screen
> structure.  There is a routine in server/ddx/cfb/cfbcmap.c called 
> cfbGetStaticColormap, but it is never referenced.
> 
> I'm no xpert, but I am wondering what the scoop is here.  As far as I can tell
> the correct way to set build routines for a server on a static color display
> is to:
> 
> Write your own CreateColormap routines hooked in as pScreen->CreateColormap
> which loops through each of the colors in the static map, calling AllocColor
> with appropriate rgb values.
> 
> (reading on in porting layer document 5.2.7.2 seems to confirm this)
> 
> So is this GetStaticColormap a dinosaur or am I missing something
> --
> Michael Toy, secret identity: the XMAN at Silicon Graphics
> Someday: mtoy@xman.sgi.com		For now: {ames,decwrl,sun}!sgi!mtoy

I can only offer a guess.

You are right that it no longer (never did?) exists in the screen
structure.  It may have served a purpose when the cfb server was being
implemented with the -DSTATIC_COLOR .  However I find no current reference
to the routine.

If you implement the routine, it can be used in your own ddx routine
pScreen->CreateColormap, to get the "appropriate rgb values" to initialize
a static colormap that is being created by the server or a client.  This
may have been its intention.  However note that the cfb implementation of
GetStaticColormap returns the Screen Default ColormapStr.  This
means that the default colormap would have to be created and assigned first
before this routine was called.  If you implemented it to simply return a
hardcoded static colormap or one that is initialized by probing the
hardware (and possibly command line options) then this restriction would
not apply to your use of the routine.

I think the most interesting "server implementor lesson" is that the
authors of the cfb routine assumed (intended?) the screen default colormap
to be static.  This makes sense.  It also suggests that all servers 
should offer at least one "Static" class visual per screen so the default
colormap for that screen can be created as a static (StaticGray,
StaticColor, or TrueColor) colormap.


Paul Shearer
M.S. 61-277
Tektronix, Inc.
P.O. Box 1000
Wilsonville, OR
	 97070-1000

W (503) 685-2137
H (503) 224-3536
tektronix!shark!paulsh