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<head>
<title>graphics(3) - Plan 9 from User Space</title>
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
</head>
<body bgcolor=#ffffff>
<table border=0 cellpadding=0 cellspacing=0 width=100%>
<tr height=10><td>
<tr><td width=20><td>
<tr><td width=20><td><b>GRAPHICS(3)</b><td align=right><b>GRAPHICS(3)</b>
<tr><td width=20><td colspan=2>
<br>
<p><font size=+1><b>NAME </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Display, Point, Rectangle, Cursor, initdraw, geninitdraw, drawerror,
initdisplay, closedisplay, getdefont, getwindow, gengetwindow,
flushimage, bufimage, lockdisplay, unlockdisplay, cursorswitch,
cursorset, openfont, buildfont, freefont, Pfmt, Rfmt, strtochan,
chantostr, chantodepth – interactive graphics
</table>
<p><font size=+1><b>SYNOPSIS </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>#include <u.h><br>
#include <libc.h><br>
#include <draw.h><br>
#include <cursor.h><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int initdraw(void (*errfun)(Display*, char*), char *font,<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
char *label)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</table>
</table>
</font></tt>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
</table>
</table>
<tt><font size=+1>int geninitdraw(char *devdir, void(*errfun)(Display*, char*),<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>char *font, char *label, char *mousedir, char *windir,<br>
int ref)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
</table>
</table>
<tt><font size=+1>int newwindow(char *str)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>void drawerror(Display *d, char *msg)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>Display*initdisplay(char *devdir, char *win, void(*errfun)(Display*,
char*))<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>void closedisplay(Display *d)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>Font* getdefont(Display *d)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int flushimage(Display *d, int vis)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int bufimage(Display *d, int n)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int lockdisplay(Display *d)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int unlockdisplay(Display *d)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int getwindow(Display *d, int ref)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int gengetwindow(Display *d, char *winname,<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Image **ip, Screen **sp, int ref)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</table>
</table>
</font></tt>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
</table>
</table>
<tt><font size=+1>void cursorswitch(Cursor *curs)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>void cursorset(Point p)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>Font* openfont(Display *d, char *name)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>Font* buildfont(Display *d, char *desc, char *name)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>void freefont(Font *f)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int Pfmt(Fmt*)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int Rfmt(Fmt*)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>ulong strtochan(char *s)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>char* chantostr(char *s, ulong chan)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int chantodepth(ulong chan)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>extern Display *display<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>extern Image *screen<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>extern Screen *_screen<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>extern Font *font<br>
</font></tt>
</table>
<p><font size=+1><b>DESCRIPTION </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
A <tt><font size=+1>Display</font></tt> structure represents a connection to the graphics device,
<a href="../man3/draw.html"><i>draw</i>(3)</a>, holding all graphics resources associated with the connection,
including in particular raster image data in use by the client
program. The structure is defined (in part) as:<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>typedef<br>
struct Display<br>
{<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
...<br>
void (*error)(Display*, char*);<br>
...<br>
Image *black;<br>
Image *white;<br>
Image *opaque;<br>
Image *transparent;<br>
Image *image;<br>
Font *defaultfont;<br>
Subfont*defaultsubfont;<br>
...<br>
</table>
};<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
</table>
A <tt><font size=+1>Point</font></tt> is a location in an Image (see below and <a href="../man3/draw.html"><i>draw</i>(3)</a>), such
as the display, and is defined as:<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>typedef<br>
struct Point {<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
int x;<br>
int y;<br>
</table>
} Point;<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
</table>
The coordinate system has <i>x</i> increasing to the right and <i>y</i> increasing
down.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
A <tt><font size=+1>Rectangle</font></tt> is a rectangular area in an image.<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>typedef<br>
struct Rectangle {<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Point min; /* upper left */<br>
Point max; /* lower right */<br>
</table>
} Rectangle;<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
</table>
By definition, <tt><font size=+1>min.x</font></tt>≤<tt><font size=+1>max.x</font></tt> and <tt><font size=+1>min.y</font></tt>≤<tt><font size=+1>max.y</font></tt>. By convention, the right
(maximum <i>x</i>) and bottom (maximum <i>y</i>) edges are excluded from the
represented rectangle, so abutting rectangles have no points in
common. Thus, <tt><font size=+1>max</font></tt> contains the coordinates of the first point
beyond the rectangle.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
The <tt><font size=+1>Image</font></tt> data structure is defined in <a href="../man3/draw.html"><i>draw</i>(3)</a>.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
A <tt><font size=+1>Font</font></tt> is a set of character images, indexed by runes (see <a href="../man7/utf.html"><i>utf</i>(7)</a>).
The images are organized into <tt><font size=+1>Subfonts</font></tt>, each containing the images
for a small, contiguous set of runes. The detailed format of these
data structures, which are described in detail in <a href="../man3/cachechars.html"><i>cachechars</i>(3)</a>,
is immaterial for most applications. <tt><font size=+1>Font</font></tt> and
<tt><font size=+1>Subfont</font></tt> structures contain two interrelated fields: <tt><font size=+1>ascent</font></tt>, the
distance from the top of the highest character (actually the top
of the image holding all the characters) to the baseline, and
<tt><font size=+1>height</font></tt>, the distance from the top of the highest character to
the bottom of the lowest character (and hence, the interline
spacing). See <a href="../man3/cachechars.html"><i>cachechars</i>(3)</a> for more details.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<i>Buildfont</i> parses the font description in the buffer <tt><font size=+1>desc</font></tt>, returning
a <tt><font size=+1>Font*</font></tt> pointer that can be used by <tt><font size=+1>string</font></tt> (see <a href="../man3/draw.html"><i>draw</i>(3)</a>) to draw
characters from the font. <i>Openfont</i> does the same, but reads the
description from the named file. <i>Freefont</i> frees a font. The convention
for naming font files is:
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>/lib/font/bit/</font></tt><i>name</i><tt><font size=+1>/</font></tt><i>range</i><tt><font size=+1>.</font></tt><i>size</i><tt><font size=+1>.font
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
</table>
where <i>size</i> is approximately the height in pixels of the lower
case letters (without ascenders or descenders). <i>Range</i> gives some
indication of which characters will be available: for example
<tt><font size=+1>ascii</font></tt>, <tt><font size=+1>latin1</font></tt>, <tt><font size=+1>euro</font></tt>, or <tt><font size=+1>unicode</font></tt>. <tt><font size=+1>Euro</font></tt> includes most European languages,
punctuation marks, the International Phonetic
Alphabet, etc., but no Oriental languages. <tt><font size=+1>Unicode</font></tt> includes every
character for which appropriate-sized images exist on the system.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
A <i>Cursor</i> is defined:<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>typedef struct<br>
Cursor {<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
Point offset;<br>
uchar clr[2*16];<br>
uchar set[2*16];<br>
</table>
} Cursor;<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
</table>
The arrays are arranged in rows, two bytes per row, left to right
in big-endian order to give 16 rows of 16 bits each. A cursor
is displayed on the screen by adding <tt><font size=+1>offset</font></tt> to the current mouse
position, using <tt><font size=+1>clr</font></tt> as a mask to draw white at the pixels where
<tt><font size=+1>clr</font></tt> is one, and then drawing black at the pixels where <tt><font size=+1>set
</font></tt>is one.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
The routine <i>initdraw</i> connects to the display; it returns –1 if
it fails and sets the error string. <i>Initdraw</i> sets up the global
variables <tt><font size=+1>display</font></tt> (the <tt><font size=+1>Display</font></tt> structure representing the connection),
<tt><font size=+1>screen</font></tt> (an <tt><font size=+1>Image</font></tt> representing the display memory itself or, if
<a href="../man1/rio.html"><i>rio</i>(1)</a> is running, the client’s window), and <tt><font size=+1>font</font></tt> (the
default font for text). The arguments to <i>initdraw</i> include a <i>label</i>,
which is written to <tt><font size=+1>/dev/label</font></tt> if non-nil so that it can be used
to identify the window when hidden (see <a href="../man1/rio.html"><i>rio</i>(1)</a>). The font is created
by reading the named <i>font</i> file. If <tt><font size=+1>font</font></tt> is null, <i>initdraw</i> reads
the file named in the environment variable <tt><font size=+1>$font</font></tt>; if
<tt><font size=+1>$font</font></tt> is not set, it imports the default (usually minimal) font
from the operating system. The global <i>font</i> will be set to point
to the resulting <tt><font size=+1>Font</font></tt> structure. The <i>errfun</i> argument is a <i>graphics
error function</i> to call in the event of a fatal error in the library;
it must never return. Its arguments are the display pointer
and an error string. If <i>errfun</i> is nil, the library provides a
default, called <i>drawerror</i>. Another effect of <i>initdraw</i> is that
it installs <a href="../man3/print.html"><i>print</i>(3)</a> formats <i>Pfmt</i> and <i>Rfmt</i> as <tt><font size=+1>%P</font></tt> and <tt><font size=+1>%R</font></tt> for printing
<tt><font size=+1>Points</font></tt> and <tt><font size=+1>Rectangles</font></tt>.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
The <i>geninitdraw</i> function provides a less automated way to establish
a connection, for programs that wish to connect to multiple displays.
<i>Devdir</i> is the name of the directory containing the device files
for the display (if nil, default <tt><font size=+1>/dev</font></tt>); <i>errfun</i>, <i>font</i>, and <i>label</i>
are as in <i>initdraw</i>; <i>mousedir</i> and <i>windir</i> are the directories
holding the <tt><font size=+1>mouse</font></tt> and <tt><font size=+1>winname</font></tt> files; and <i>ref</i> specifies the refresh
function to be used to create the window, if running under <a href="../man1/rio.html"><i>rio</i>(1)</a>
(see <a href="../man3/window.html"><i>window</i>(3)</a>).
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<i>Initdisplay</i> is part of <i>geninitdraw</i>; it sets up the display structures
but does not allocate any fonts or call <i>getwindow</i>. The arguments
are similar to those of <i>initdraw</i>; <i>win</i> names the directory, default
<tt><font size=+1>/dev</font></tt>, in which the files associated with the window reside. <i>Closedisplay</i>
disconnects the display and frees the associated
data structures. <i>Getdefont</i> builds a <tt><font size=+1>Font</font></tt> structure from in-core
data describing a default font. None of these routines is needed
by most programs, since <i>initdraw</i> calls them as needed.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
The data structures associated with the display must be protected
in a multi-process program, because they assume only one process
will be using them at a time. Multi-process programs should set
<tt><font size=+1>display−>locking</font></tt> to <tt><font size=+1>1</font></tt>, to notify the library to use a locking protocol
for its own accesses, and call <i>lockdisplay</i> and
<i>unlockdisplay</i> around any calls to the graphics library that will
cause messages to be sent to the display device. <i>Initdraw</i> and
<i>geninitdraw</i> initialize the display to the locked state.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<i>Getwindow</i> returns a pointer to the window associated with the
application; it is called automatically by <i>initdraw</i> to establish
the <tt><font size=+1>screen</font></tt> pointer but must be called after each resizing of the
window to restore the library’s connection to the window. If <tt><font size=+1>rio</font></tt>
is not running, it returns <tt><font size=+1>display−>image</font></tt>; otherwise it
negotiates with <tt><font size=+1>rio</font></tt> by looking in <tt><font size=+1>/dev/winname</font></tt> to find the name
of the window and opening it using <tt><font size=+1>namedimage</font></tt> (see <a href="../man3/allocimage.html"><i>allocimage</i>(3)</a>).
The resulting window will be created using the refresh method
<i>ref</i> (see <a href="../man3/window.html"><i>window</i>(3)</a>); this should almost always be <tt><font size=+1>Refnone</font></tt> because
<tt><font size=+1>rio</font></tt> provides backing store for the window.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<i>Getwindow</i> overwrites the global variables <tt><font size=+1>screen</font></tt>, a pointer to
the <tt><font size=+1>Image</font></tt> defining the window (or the overall display, if no window
system is running); and <tt><font size=+1>_screen</font></tt>, a pointer to the <tt><font size=+1>Screen</font></tt> representing
the root of the window’s hierarchy. (See <a href="../man3/window.html"><i>window</i>(3)</a>. The overloading
of the <tt><font size=+1>screen</font></tt> word is an unfortunate
historical accident.) <i>Getwindow</i> arranges that <tt><font size=+1>screen</font></tt> point to
the portion of the window inside the border; sophisticated clients
may use <tt><font size=+1>_screen</font></tt> to make further subwindows. <i>Gengetwindow</i>’s extra
arguments are the full path of the window’s <tt><font size=+1>winname</font></tt> file and pointers
to be overwritten with the values of the
‘global’ <tt><font size=+1>Image</font></tt> and <tt><font size=+1>Screen</font></tt> variables for the new window.
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The mouse cursor is always displayed. The initial cursor is an
arrow. <i>Cursorswitch</i> causes the argument cursor to be displayed
instead. A zero argument causes a switch back to the arrow cursor.
<i>Cursorset</i> moves the mouse cursor to position <i>p</i>, provided (if in
a window) that the requesting program is executing in the
current window and the mouse is within the window boundaries;
otherwise <i>cursorset</i> is a no-op.
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The graphics functions described in <a href="../man3/draw.html"><i>draw</i>(3)</a>, <a href="../man3/allocimage.html"><i>allocimage</i>(3)</a>, <a href="../man3/cachechars.html"><i>cachechars</i>(3)</a>,
and <a href="../man3/subfont.html"><i>subfont</i>(3)</a> are implemented by writing commands to files under
<tt><font size=+1>/dev/draw</font></tt> (see <a href="../man3/draw.html"><i>draw</i>(3)</a>); the writes are buffered, so the functions
may not take effect immediately. <i>Flushimage</i> flushes the buffer,
doing all pending graphics operations. If
<i>vis</i> is non-zero, any changes are also copied from the ‘soft screen’
(if any) in the driver to the visible frame buffer. The various
allocation routines in the library flush automatically, as does
the event package (see <a href="../man3/event.html"><i>event</i>(3)</a>); most programs do not need to
call <i>flushimage</i>. It returns –1 on error.
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<i>Bufimage</i> is used to allocate space for <i>n</i> bytes in the display
buffer. It is used by all the graphics routines to send messages
to the display.
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The functions <i>strtochan</i> and <i>chantostr</i> convert between the channel
descriptor strings used by <a href="../man7/image.html"><i>image</i>(7)</a> and the internal <tt><font size=+1>ulong</font></tt> representation
used by the graphics protocol (see <a href="../man3/draw.html"><i>draw</i>(3)</a>’s <tt><font size=+1>b</font></tt> message). <tt><font size=+1>Chantostr</font></tt>
writes at most nine bytes into the buffer pointed at by <i>s</i> and
returns <i>s</i> on success, 0 on failure.
<tt><font size=+1>Chantodepth</font></tt> returns the number of bits per pixel used by the format
specified by <i>chan</i>. Both <tt><font size=+1>chantodepth</font></tt> and <tt><font size=+1>strtochan</font></tt> return 0 when
presented with bad input.<br>
</table>
<p><font size=+1><b>EXAMPLES </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
To reconnect to the window after a resize event,<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>if(getwindow(display, Refnone) < 0)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
sysfatal("resize failed: %r");<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</table>
</font></tt>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
</table>
</table>
To create and set up a new <a href="../man1/rio.html"><i>rio</i>(1)</a> window,<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>Image *screen2;<br>
Screen *_screen2;<br>
srvwsys = getenv("wsys");<br>
if(srvwsys == nil)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
sysfatal("can't find $wsys: %r");<br>
</table>
rfork(RFNAMEG); /* keep mount of rio private */<br>
fd = open(srvwsys, ORDWR);<br>
if(fd < 0)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
sysfatal("can't open $wsys: %r");<br>
</table>
/* mount creates window; see</font></tt> <i>rio</i><tt><font size=+1>(4) */<br>
if(mount(fd, −1, "/tmp", MREPL, "new −dx 300−dy 200") < 0)<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
sysfatal("can't mount new window: %r");<br>
</table>
if(gengetwindow(display, "/tmp/winname",<br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
&screen2, &_screen2, Refnone) < 0)<br>
sysfatal("resize failed: %r");<br>
</table>
/* now open /tmp/cons, /tmp/mouse */<br>
...<br>
</font></tt>
</table>
</table>
<p><font size=+1><b>FILES </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>/usr/local/plan9/font/bit </font></tt> directory of fonts<br>
</table>
<p><font size=+1><b>SOURCE </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>/usr/local/plan9/src/libdraw<br>
</font></tt>
</table>
<p><font size=+1><b>SEE ALSO </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<a href="../man1/rio.html"><i>rio</i>(1)</a>, <a href="../man3/addpt.html"><i>addpt</i>(3)</a>, <a href="../man3/allocimage.html"><i>allocimage</i>(3)</a>, <a href="../man3/cachechars.html"><i>cachechars</i>(3)</a>, <a href="../man3/subfont.html"><i>subfont</i>(3)</a>, <a href="../man3/draw.html"><i>draw</i>(3)</a>,
<a href="../man3/event.html"><i>event</i>(3)</a>, <a href="../man3/frame.html"><i>frame</i>(3)</a>, <a href="../man3/print.html"><i>print</i>(3)</a>, <a href="../man3/window.html"><i>window</i>(3)</a>, <a href="../man3/draw.html"><i>draw</i>(3)</a>, <a href="../man7/image.html"><i>image</i>(7)</a>, <a href="../man7/font.html"><i>font</i>(7)</a><br>
</table>
<p><font size=+1><b>DIAGNOSTICS </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
An error function may call <a href="../man3/errstr.html"><i>errstr</i>(3)</a> for further diagnostics.<br>
</table>
<p><font size=+1><b>BUGS </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
The names <tt><font size=+1>clr</font></tt> and <tt><font size=+1>set</font></tt> in the <tt><font size=+1>Cursor</font></tt> structure are reminders of
an archaic color map and might be more appropriately called <tt><font size=+1>white</font></tt>
and <tt><font size=+1>black</font></tt>.
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These manual pages contain many references to the now-fictitious
<tt><font size=+1>/dev/draw</font></tt>.<br>
</table>
<td width=20>
<tr height=20><td>
</table>
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