Path: utzoo!attcan!uunet!samsung!sol.ctr.columbia.edu!lll-winken!sun-barr!newstop!dreams!rbogen
From: rbogen@dreams.EBay.Sun.COM (Richard A. Bogen)
Newsgroups: comp.windows.news
Subject: Colormap Manipulation
Message-ID: <2833@dreams.EBay.Sun.COM>
Date: 3 Aug 90 17:32:04 GMT
Organization: Sun Microsystems, Inc.  Mt. View, Ca.
Lines: 29


% This example shows how to change a color in the hardware colormap
% at a particular pixel index without modifying the other colors
%
% Richard A. Bogen - Sun Microsystems, Inc. - August 1990
%
/zapcolor {% slot color => -

4 dict begin
  /COLOR exch def
  /SLOT exch def

% Assume pseduocolor is the default for the framebuffer
% If not then change this to locate a pseudocolor visual somewhere
/cmap framebuffer /Visual get createcolormap def  

% Load virtual map with existing colors in hardware map
% by creating a single segment and copying in current colors
/seg cmap 256 0 createcolorsegment def
seg {dup /Slot get dup setpixel currentcolor putcolor} forall 

% Replace desired slot with desired color
seg SLOT get SLOT COLOR putcolor

% Now install into the hardware
% Note: olwm will deinstall when cursor is moved out of current window
cmap /Installed true put

end} def