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<article>
<title>X11-big-cursor MINIHOWTO<subtitle>How to use enlarged mouse cursors with the X window system
<author><url name="J&oe;rg Schneider" url="mailto:joerg.schneider@ira.uka.de">
<date>v2, 11 August 1997
<abstract>
This document describes how to use enlarged mouse cursors with the X
window system.
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<item><htmlurl url="#intro" name="Introduction">
<item><htmlurl url="#howto" name="How to do it">
<item><htmlurl url="#notes" name="Notes and limitations">
<item><htmlurl url="#tech" name="Technical discussion">
<item><htmlurl url="#ideas" name="Other ideas how to make the mouse cursor more visible">
<item><htmlurl url="#info" name="Related info">
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<item><htmlurl url="#fontserver" name="How to use a fontserver">
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<item><htmlurl url="#fsconfig" name="Setting up a font server">
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<item><htmlurl url="#getbdf" name="How to get the bdf source for some font">
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</abstract>
<toc>
<sect>Introduction<label id=top>
<p>There are several reasons why the standard X mouse cursors are hard to
track for some people:
<itemize>
<item> when running X on a notebook with low contrast LCD
<item> on normal screens when using high resolution, 1600x1280 e. g.
<item> for visually impaired persons even on normal hardware
</itemize>
In all cases it might help to use enlarged mouse cursors. Ideally this
job should be done by a single X program that automatically enlarges
every mouse cursor.
To my knowledge there is no simple way to write a utility like this,
because the X protocol has no provision to query mouse cursors. For
more details see section <ref id="tech" name="Technical discussion"> below.
If we aim for a less general goal, though, something can be done:
There is a set of standard mouse cursors that can be found in the
cursor font (try <TT>xfd -fn cursor</TT> to look at it). Most programs use
these mouse cursors and the key idea is to replace the standard cursor
font with an enlarged version.
<sect>About this document
<p>
The motivation for this MINIHOWTO was a visually impaired co-student
who asked me how to enlarge the mouse cursor under X. After I found
out how this can be done, I wrote an initial version of this
document. The knowledge about the method described here does not seem
to be common, so I decided to share it and submitted this document as
a Linux MINIHOWTO, despite the fact that it is
<em/not specific to Linux at all/. As all other MINIHOWTOs it can be
found in the home of of the <url name="Linux Documentation Project
(LDP)" url="http://sunsite.unc.edu/LDP/HOWTO/">.
The <url name=master
url="http://i11www.ira.uka.de/˜schneid/X11-big-cursor/master/"> of
this document is maintained in the SGML/linuxdoc format. This makes it
possible to automatically provide versions in the following formats
(which can be found in the same place as the master): html, text,
LaTeX, DVI, PostScript, GNU info.
<url name="Shinobu Miyata" url="mailto:shinobu@emichan.rim.or.jp"> has
done a Japanese translation of this MINIHOWTO. It can be found in <url
url="http://i11www.ira.uka.de/˜schneid/jp/X11-big-cursor/">.
<sect>How to do it<label id=howto>
<p>
Follow the steps detailed below. If you don't want to get and compile
the bdfresize package yourself, you can skip to step 3 and download a
magnified font instead of creating it.
<enum>
<item> get cursor.bdf, the source of the cursor font, from some X
distribution, e. g. from <url
url="ftp://ftp.x.org/pub/R6.3/xc/fonts/bdf/misc/cursor.bdf"> (if you don't
find it there try an archie search or get it from <url name="my copy"
url="http://i11www.ira.uka.de/˜schneid/X11-big-cursor/cursor.bdf">).
<item> get, compile and install the bdfresize package from
<url url="ftp://ftp.cs.titech.ac.jp/X11/contrib/Local/bdfresize-1.4.tar.Z">
(or from <url name="my copy"
url="http://i11www.ira.uka.de/˜schneid/X11-big-cursor/bdfresize-1.4.tar.gz">):
<verb>
zcat bdfresize-1.4.tar.Z | tar xf -
cd bdfresize-1.4
xmkmf
make
</verb>
On Linux you probably have to use:
<verb>
make CCOPTIONS='-include /usr/include/bsd/bsd.h' clean all
</verb>
<item> create a directory and install a magnified cursor font in it
(magnification factor 2 in this example):
<verb>
mkdir $HOME/fonts
bdfresize -f 2 cursor.bdf | bdftopcf >$HOME/fonts/cursor2.pcf
mkfontdir $HOME/fonts
</verb>
I have prepared some <url name="cursor fonts"
url="http://i11www.ira.uka.de/˜schneid/X11-big-cursor/fonts/">
with the following magnification factors: 1.5, 2, 2.5, 3, 4, 5,
6, 7, 8 and 16. You can download one of them an copy it to
<tt>$HOME/fonts</tt> if you don't want to use bdfresize.
<item> modify your <TT>.xinitrc</TT> or <TT>.xsession</TT> file: before
any X client (that uses cursors) is started the following
commands must be executed:
<verb>
xset +fp $HOME/fonts
xsetroot -cursor_name X_cursor
</verb>
<item> leave your X session and restart.
</enum>
That's it—now all mouse cursors should have doubled in size.
<sect>Notes and limitations<label id=notes>
<p>
<itemize>
<item> X servers may have a limit for the maximum cursor
size, especially if they use a hardware implementation for the mouse
cursor. Others do not have such a limit. E. g. XF86_S3 3.3
works even with a 512x512 mouse cursor (rather slowly).
<item> The magnified cursor font must have the same name as the original
font (the <em/font name/ must be <TT>cursor</TT>, <em/file name/ does not
matter)—that is no problem as <TT>bdfresize</TT> does not change
the font name.
<item> The directory with the new cursor font must be placed before the
directory with the standard cursor font in the the font path—this
is accomplished with <TT>xset +fp</TT> (as opposed to
<TT>xset fp+</TT>).
<item> Changes in <tt>$HOME/fonts/</tt> will be visible only
after the command <TT>mkfontdir $HOME/fonts; xset fp rehash</TT>
and only in newly
started X clients (more exactly: for newly created cursors).
<item> <TT>xset +fp path</TT> may not work on a X-Terminal. In this case
a font server (see the section <ref id=fontserver
name="How to use a fontserver">)
can be used if supported by the X-Terminal or some
other method to install the font on the X-Terminal (this can
generally only be done by your system administrator).
<item> The same approach can be used for <TT>olcursor</TT> and
<tt>decw$cursor</tt> fonts and any other cursor font you may
encounter.
<item> Cursor fonts produced by bdfresize don't look smooth,
especially at larger magnification factors. It would be nice if
someone could create better looking handcrafted version at
some common sizes.
</itemize>
<sect>Technical discussion<label id=tech>
<p>Is it possible to write a X program that enlarges cursors
automatically?
<descrip>
<tag/(Partial) solution 1/ Use the XTestCompareCursor from the XTEST
extension. For all windows that the mouse pointer enters compare the
cursor of this window with a set of `known' cursors (e. g. from
the cursor font). If the cursor is found, replace it with an enlarged
version, otherwise either leave it alone or substitute a standard
cursor. This will only work where the XTest extension is available.
<tag/Solution 2/ Write a proxy X server that relays all client requests
unchanged to the real X server, except that it intercepts all requests
corresponing to the <TT>XCreate*Cursor</TT> Xlib
functions. <TT>XCreate*Cursor</TT> requests should be modified to use
an enlarged cursor.
This proxy server simulates a new display, e. g. <tt/:1/. All
clients that connect to this display (e. g. <tt/xterm -display
:1/) are displayed on the real server (normally <tt/:0/) and their
mouse cursors are enlarged automatically. The mouse cursors of clients
that connect to <tt/:0/ will remain <em/unchanged/.
</descrip>
<sect>Other ideas how to make the mouse cursor more visible<label id=ideas>
<p>Here are some ideas for rather simple X programs that might make
mouse cursors easier to track.
<itemize>
<item> When a hot key is pressed display something (big cursor, small
window, shaped window) at pointer position for 0.5s.
<item> use XRecolorCursor to change the mouse cursor color every 0.1s
</itemize>
A more demanding project would be <bf/mouse trails/ à la
windoze, i. e. when the mouse is moved and the mouse cursor needs
to be drawn in a different position, then the old mouse cursor does
not disappear at once, but after a short delay. Mouse trails would be
probably best implemented in a X server, but it might be feasible to
do it as a X client, or better as a proxy server (see section <ref id="tech"
name="Technical discussion"> for details).
<sect>Related info<label id=info>
<sect1>How to use a font server<label id=fontserver>
<p>A font server is a net service that provides a set of X11 fonts
with a simple protocol. It can be queried which fonts it provides and
will supply the font bitmap data on request.
You might want to use a font server to provide the X server with a
modified cursor font, instead of telling it where to find the font on
the file system.
This method is especially handy if you use several machines that don't
share a common file system or if you use X terminals that support
the font server protocol.
A font server program and associated tools comes with the X11R5+
distribution (AFAIK).
<sect2>Setting up a font server<label id=fsconfig>
<p>Read the manual pages <em>fs(1)</em>, <em>fslsfonts(1)</em> (or
<em>xfs(1)</em>, <em>xfslsfonts(1)</em> under X11R6) and try it—it isn't
hard. Say, you are running the server on host <TT>some.host.edu</TT>
on port 7100. You can test the setup with the command
<TT>fslsfonts -server some.host.edu:7100</TT>
To actually use the server issue the command
<TT>xset +fp tcp/some.host.edu:7100</TT>
which should return without an error message.
<sect1>How to get the bdf source for some font<label id=getbdf>
<p>If you have set up a font server simply use <TT>fstobdf</TT> which
comes with the font server.
Alternatively you may try <TT>getbdf</TT> which can dump any installed
X11 font to a bdf file.
</article>
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