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diff --git a/doc/groff.html.node/Ligatures-and-Kerning.html b/doc/groff.html.node/Ligatures-and-Kerning.html new file mode 100644 index 0000000..b00ed74 --- /dev/null +++ b/doc/groff.html.node/Ligatures-and-Kerning.html @@ -0,0 +1,157 @@ +<!DOCTYPE html> +<html> +<!-- Created by GNU Texinfo 7.0.3, https://www.gnu.org/software/texinfo/ --> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> +<!-- This manual documents GNU troff version 1.23.0. + +Copyright © 1994-2023 Free Software Foundation, Inc. + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License, Version 1.3 or +any later version published by the Free Software Foundation; with no +Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A +copy of the license is included in the section entitled "GNU Free +Documentation License". --> +<title>Ligatures and Kerning (The GNU Troff Manual)</title> + +<meta name="description" content="Ligatures and Kerning (The GNU Troff Manual)"> +<meta name="keywords" content="Ligatures and Kerning (The GNU Troff Manual)"> +<meta name="resource-type" content="document"> +<meta name="distribution" content="global"> +<meta name="Generator" content="makeinfo"> +<meta name="viewport" content="width=device-width,initial-scale=1"> + +<link href="index.html" rel="start" title="Top"> +<link href="Request-Index.html" rel="index" title="Request Index"> +<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents"> +<link href="Using-Fonts.html" rel="up" title="Using Fonts"> +<link href="Dummy-Characters.html" rel="next" title="Dummy Characters"> +<link href="Artificial-Fonts.html" rel="prev" title="Artificial Fonts"> +<style type="text/css"> +<!-- +a.copiable-link {visibility: hidden; text-decoration: none; line-height: 0em} +span.r {font-family: initial; font-weight: normal; font-style: normal} +span:hover a.copiable-link {visibility: visible} +strong.def-name {font-family: monospace; font-weight: bold; font-size: larger} +--> +</style> + + +</head> + +<body lang="en"> +<div class="subsection-level-extent" id="Ligatures-and-Kerning"> +<div class="nav-panel"> +<p> +Next: <a href="Dummy-Characters.html" accesskey="n" rel="next">Dummy Characters</a>, Previous: <a href="Artificial-Fonts.html" accesskey="p" rel="prev">Artificial Fonts</a>, Up: <a href="Using-Fonts.html" accesskey="u" rel="up">Using Fonts</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Request-Index.html" title="Index" rel="index">Index</a>]</p> +</div> +<hr> +<h4 class="subsection" id="Ligatures-and-Kerning-1">5.19.8 Ligatures and Kerning</h4> +<a class="index-entry-id" id="index-ligatures-and-kerning"></a> +<a class="index-entry-id" id="index-kerning-and-ligatures"></a> + +<p>Ligatures are groups of characters that are run together, i.e, producing +a single glyph. For example, the letters ‘f’ and ‘i’ can form a +ligature ‘fi’ as in the word ‘file’. This produces a cleaner look +(albeit subtle) to the printed output. Usually, ligatures are not +available in fonts for TTY output devices. +</p> +<p>Most PostScript fonts support the fi and fl ligatures. The C/A/T +typesetter that was the target of <abbr class="acronym">AT&T</abbr> <code class="code">troff</code> also +supported ‘ff’, ‘ffi’, and ‘ffl’ ligatures. Advanced typesetters or +‘expert’ fonts may include ligatures for ‘ft’ and ‘ct’, although GNU +<code class="code">troff</code> does not support these (yet). +</p> +<p>Only the current font is checked for ligatures and kerns; neither +special fonts nor special charcters defined with the <code class="code">char</code> request +(and its siblings) are taken into account. +</p> +<dl class="first-deffn"> +<dt class="deffn" id="index-_002elg"><span class="category-def">Request: </span><span><strong class="def-name"><code class="t">.lg</code></strong> <var class="def-var-arguments">[<span class="r"><i class="slanted">flag</i></span>]</var><a class="copiable-link" href='#index-_002elg'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-lg"></a> +</dd><dt class="deffnx def-cmd-deffn" id="index-_005cn_005b_002elg_005d"><span class="category-def">Register: </span><span><strong class="def-name"><code class="t">\n[.lg]</code></strong><a class="copiable-link" href='#index-_005cn_005b_002elg_005d'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-_002elg-1"></a> +<a class="index-entry-id" id="index-activating-ligatures-_0028lg_0029"></a> +<a class="index-entry-id" id="index-ligatures_002c-activating-_0028lg_0029"></a> +<a class="index-entry-id" id="index-ligatures-enabled-register-_0028_002elg_0029"></a> +<p>Switch the ligature mechanism on or off; if the parameter is non-zero or +missing, ligatures are enabled, otherwise disabled. Default is on. The +current ligature mode can be found in the read-only register <code class="code">.lg</code> +(set to 1 or 2 if ligatures are enabled, 0 otherwise). +</p> +<p>Setting the ligature mode to 2 enables the two-character ligatures +(fi, fl, and ff) and disables the three-character ligatures (ffi and +ffl). +</p></dd></dl> + +<p><em class="dfn">Pairwise kerning</em> is another subtle typesetting mechanism that +modifies the distance between a glyph pair to improve readability. In +most cases (but not always) the distance is decreased. +Typewriter-like fonts and fonts for terminals where all glyphs have the +same width don’t use kerning. +</p> +<dl class="first-deffn"> +<dt class="deffn" id="index-_002ekern"><span class="category-def">Request: </span><span><strong class="def-name"><code class="t">.kern</code></strong> <var class="def-var-arguments">[<span class="r"><i class="slanted">flag</i></span>]</var><a class="copiable-link" href='#index-_002ekern'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-kern"></a> +</dd><dt class="deffnx def-cmd-deffn" id="index-_005cn_005b_002ekern_005d"><span class="category-def">Register: </span><span><strong class="def-name"><code class="t">\n[.kern]</code></strong><a class="copiable-link" href='#index-_005cn_005b_002ekern_005d'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-_002ekern-1"></a> +<a class="index-entry-id" id="index-activating-kerning-_0028kern_0029"></a> +<a class="index-entry-id" id="index-kerning_002c-activating-_0028kern_0029"></a> +<a class="index-entry-id" id="index-kerning-enabled-register-_0028_002ekern_0029"></a> +<p>Switch kerning on or off. If the parameter is non-zero or missing, +enable pairwise kerning, otherwise disable it. The read-only register +<code class="code">.kern</code> is set to 1 if pairwise kerning is enabled, +0 otherwise. +</p> +<a class="index-entry-id" id="index-dummy-character-_0028_005c_0026_0029_002c-effect-on-kerning"></a> +<a class="index-entry-id" id="index-character_002c-dummy-_0028_005c_0026_0029_002c-effect-on-kerning"></a> +<p>If the font description file contains pairwise kerning information, +glyphs from that font are kerned. Kerning between two glyphs can be +inhibited by placing <code class="code">\&</code> between them: ‘<samp class="samp">V\&A</samp>’. +</p> +<p>See <a class="xref" href="Font-Description-File-Format.html">Font Description File Format</a>. +</p></dd></dl> + +<a class="index-entry-id" id="index-track-kerning"></a> +<a class="index-entry-id" id="index-kerning_002c-track"></a> +<p><em class="dfn">Track kerning</em> expands or reduces the space between glyphs. This +can be handy, for example, if you need to squeeze a long word onto a +single line or spread some text to fill a narrow column. It must be +used with great care since it is usually considered bad typography if +the reader notices the effect. +</p> +<dl class="first-deffn"> +<dt class="deffn" id="index-_002etkf"><span class="category-def">Request: </span><span><strong class="def-name"><code class="t">.tkf</code></strong> <var class="def-var-arguments">f s1 n1 s2 n2</var><a class="copiable-link" href='#index-_002etkf'> ¶</a></span></dt> +<dd><a class="index-entry-id" id="index-tkf"></a> +<a class="index-entry-id" id="index-activating-track-kerning-_0028tkf_0029"></a> +<a class="index-entry-id" id="index-track-kerning_002c-activating-_0028tkf_0029"></a> +<p>Enable track kerning for font <var class="var">f</var>. If the current font +is <var class="var">f</var> the width of every glyph is increased by an amount +between <var class="var">n1</var> and <var class="var">n2</var> (<var class="var">n1</var>, <var class="var">n2</var> can be negative); if +the current type size is less than or equal to <var class="var">s1</var> the width is +increased by <var class="var">n1</var>; if it is greater than or equal to <var class="var">s2</var> the +width is increased by <var class="var">n2</var>; if the type size is greater than or +equal to <var class="var">s1</var> and less than or equal to <var class="var">s2</var> the increase in +width is a linear function of the type size. +</p> +<p>The default scaling unit is ‘<samp class="samp">z</samp>’ for <var class="var">s1</var> and <var class="var">s2</var>, ‘<samp class="samp">p</samp>’ +for <var class="var">n1</var> and <var class="var">n2</var>. +</p> +<p>The track kerning amount is added even to the rightmost glyph in a line; +for large values it is thus recommended to increase the line length by +the same amount to compensate. +</p></dd></dl> + + +</div> +<hr> +<div class="nav-panel"> +<p> +Next: <a href="Dummy-Characters.html">Dummy Characters</a>, Previous: <a href="Artificial-Fonts.html">Artificial Fonts</a>, Up: <a href="Using-Fonts.html">Using Fonts</a> [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Request-Index.html" title="Index" rel="index">Index</a>]</p> +</div> + + + +</body> +</html> |