/*********************************************************************** 
    Module:  Readme.colors
 
    Copyright (C) 1996 Harold Youngren, Mark Drela 
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

    Report problems to:    guppy@maine.com
                        or drela@mit.edu  
***********************************************************************/ 

Xplot11  
C     Version 4.46 11/28/01


This Readme file pertains to problems with colors under some window managers.

The color routines used here employ shared colormaps to avoid the major screen
color dislocations that accompany switching mouse focus with private colormaps.
When the window manager leaves a sufficient number of color entries unallocated
this approach works fine.  Newer window managers, notably the fvwm-95 variants
that are now supplied with the Linux distributions, appear to eat up almost
the complete colormap for themselves with allocations for many pixmaps for
icons.  This causes heartaches when using Xplot11 as you get lots of messages  
about trouble allocating colors (and the colors are messed up in the plot). 

This could be avoided by allocating private colormaps but this gets into the 
color flashing problem alluded to above.  

For the time being I suggest using a window manager that doesn't go overboard
allocating lots of colors.  Twm works fine, I use plain old fvwm with xfm
for my usual interface, I set up an .fvwmrc file that does not use 
too many wasteful color features (like lots of pixmap icons).  This leaves 
around 200 free colors most of the time.  Note that if you run something like 
xv displaying a typical color gif file you will eat up most or all the free 
colors while that application is running.  Once you quit xv (or whatever) the
colors are freed and clashes with Xplot11 disappear.

If there is a sufficient problem with this I will make an option of allocating
a private colormap when no color space is available in the shared colormap...

HY

