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<html>
<head>
<meta name="generator" content=
- "HTML Tidy for Linux (vers 25 March 2009), see www.w3.org">
+ "HTML Tidy for HTML5 for Linux version 5.2.0">
<title>A Hacker's Guide to Ncurses Internals</title>
<link rel="author" href="mailto:bugs-ncurses@gnu.org">
</ul>
</li>
- <li><a href="#portability">Portability and
- Configuration</a></li>
+ <li><a href="#portability">Portability and Configuration</a></li>
<li><a href="#documentation">Documentation Conventions</a></li>
These have to be viewable through traditional <em>man(1)</em>
programs.</li>
- <li><strong>Write everything else in HTML.</strong></li>
+ <li><strong>Write everything else in HTML.</strong>
+ </li>
</ol>
<p>When in doubt, HTMLize a master and use <em>lynx(1)</em> to
majordomo list; to join, write to
<code>bug-ncurses-request@gnu.org</code> with a message
containing the line:</p>
+
<pre>
subscribe <name>@<host.domain>
</pre>
<p>Tell us about every terminal on which you have reproduced
the bug — and every terminal on which you cannot.
- Ideally, sent us terminfo sources for all of these (yours
+ Ideally, send us terminfo sources for all of these (yours
might differ from ours).</p>
<p>Include your ncurses version and your OS/machine type, of
<p>Here are some more details about mouse event handling:</p>
- <p>The <code>lib_mouse()</code>code is logically split into a
+ <p>The <code>lib_mouse()</code> code is logically split into a
lower level that accepts event reports in a device-dependent
format and an upper level that parses mouse gestures and filters
events. The mediating data structure is a circular queue of event
reports (low-level events) into a gesture (a high-level or
composite event).</p>
- <h3><a name="output" id="output">Output and Screen
- Updating</a></h3>
+ <h3><a name="output" id="output">Output and Screen Updating</a></h3>
<p>With the single exception of character echoes during a
<code>wgetnstr()</code> call (which simulates cooked-mode line
<code>lib_mvcur.c</code>. Essentially, what happens looks like
this:</p>
- <p>The <code>hashmap.c</code> module tries to detect vertical
- motion changes between the real and virtual screens. This
- information is represented by the oldindex members in the newscr
- structure. These are modified by vertical-motion and clear
- operations, and both are re-initialized after each update. To
- this change-journalling information, the hashmap code adds
- deductions made using a modified Heckel algorithm on hash values
- generated from the line contents.</p>
-
- <p>The <code>hardscroll.c</code> module computes an optimum set
- of scroll, insertion, and deletion operations to make the indices
- match. It calls <code>_nc_mvcur_scrolln()</code> in
- <code>lib_mvcur.c</code> to do those motions.</p>
-
- <p>Then <code>lib_doupdate.c</code> goes to work. Its job is to
- do line-by-line transformations of <code>curscr</code> lines to
- <code>newscr</code> lines. Its main tool is the routine
- <code>mvcur()</code> in <code>lib_mvcur.c</code>. This routine
- does cursor-movement optimization, attempting to get from given
- screen location A to given location B in the fewest output
- characters possible.</p>
+ <ul>
+ <li>
+ <p>The <code>hashmap.c</code> module tries to detect vertical
+ motion changes between the real and virtual screens. This
+ information is represented by the oldindex members in the
+ newscr structure. These are modified by vertical-motion and
+ clear operations, and both are re-initialized after each
+ update. To this change-journalling information, the hashmap
+ code adds deductions made using a modified Heckel algorithm
+ on hash values generated from the line contents.</p>
+ </li>
+
+ <li>
+ <p>The <code>hardscroll.c</code> module computes an optimum
+ set of scroll, insertion, and deletion operations to make the
+ indices match. It calls <code>_nc_mvcur_scrolln()</code> in
+ <code>lib_mvcur.c</code> to do those motions.</p>
+ </li>
+
+ <li>
+ <p>Then <code>lib_doupdate.c</code> goes to work. Its job is
+ to do line-by-line transformations of <code>curscr</code>
+ lines to <code>newscr</code> lines. Its main tool is the
+ routine <code>mvcur()</code> in <code>lib_mvcur.c</code>.
+ This routine does cursor-movement optimization, attempting to
+ get from given screen location A to given location B in the
+ fewest output characters possible.</p>
+ </li>
+ </ul>
<p>If you want to work on screen optimizations, you should use
the fact that (in the trace-enabled version of the library)
<code>include/curses.h.in</code> for mask values, near the
end.</p>
- <h1><a name="fmnote" id="fmnote">The Forms and Menu
- Libraries</a></h1>
+ <h1><a name="fmnote" id="fmnote">The Forms and Menu Libraries</a></h1>
<p>The forms and menu libraries should work reliably in any
environment you can port ncurses to. The only portability issue
This version has been slightly cleaned up for
<code>ncurses</code>.</p>
- <h1><a name="tic" id="tic">A Tour of the Terminfo
- Compiler</a></h1>
+ <h1><a name="tic" id="tic">A Tour of the Terminfo Compiler</a></h1>
<p>The <strong>ncurses</strong> implementation of
<strong>tic</strong> is rather complex internally; it has to do a
<dd>gettimeofday(), select().</dd>
</dl>
+
<hr>
<address>
Eric S. Raymond <esr@snark.thyrsus.com>
- </address>(Note: This is <em>not</em> the <a href="#bugtrack">bug
+ </address>
+ (Note: This is <em>not</em> the <a href="#bugtrack">bug
address</a>!)
</body>
</html>
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