opentype.xml

Pango is a library for layout and rendering of text, with an emphasis on internationalization. Pang

<refentry id="pango-OpenType-Font-Handling">
<refmeta>
<refentrytitle role="top_of_page" id="pango-OpenType-Font-Handling.top_of_page">OpenType Font Handling</refentrytitle>
<manvolnum>3</manvolnum>
<refmiscinfo>PANGO Library</refmiscinfo>
</refmeta>

<refnamediv>
<refname>OpenType Font Handling</refname>
<refpurpose>Obtaining information from OpenType tables</refpurpose>
<!--[<xref linkend="desc" endterm="desc.title"/>]-->
</refnamediv>
<refsect1 id="pango-OpenType-Font-Handling.stability-level">
<title>Stability Level</title>
Unstable, unless otherwise indicated
</refsect1>

<refsynopsisdiv id="pango-OpenType-Font-Handling.synopsis" role="synopsis">
<title role="synopsis.title">Synopsis</title>
<anchor id="PangoOTInfo"/><anchor id="PangoOTRuleset"/>
<synopsis>
typedef             <link linkend="PangoOTTag">PangoOTTag</link>;
                    <link linkend="PangoOTInfo-struct">PangoOTInfo</link>;
                    <link linkend="PangoOTBuffer">PangoOTBuffer</link>;
                    <link linkend="PangoOTGlyph">PangoOTGlyph</link>;
                    <link linkend="PangoOTRuleset-struct">PangoOTRuleset</link>;
                    <link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link>;
enum                <link linkend="PangoOTTableType">PangoOTTableType</link>;
                    <link linkend="PangoOTFeatureMap">PangoOTFeatureMap</link>;
#define             <link linkend="PANGO-OT-TAG-MAKE:CAPS">PANGO_OT_TAG_MAKE</link>                   (c1,c2,c3,c4)
#define             <link linkend="PANGO-OT-TAG-MAKE-FROM-STRING:CAPS">PANGO_OT_TAG_MAKE_FROM_STRING</link>       (s)
#define             <link linkend="PANGO-OT-ALL-GLYPHS:CAPS">PANGO_OT_ALL_GLYPHS</link>
#define             <link linkend="PANGO-OT-NO-FEATURE:CAPS">PANGO_OT_NO_FEATURE</link>
#define             <link linkend="PANGO-OT-NO-SCRIPT:CAPS">PANGO_OT_NO_SCRIPT</link>
#define             <link linkend="PANGO-OT-DEFAULT-LANGUAGE:CAPS">PANGO_OT_DEFAULT_LANGUAGE</link>
#define             <link linkend="PANGO-OT-TAG-DEFAULT-LANGUAGE:CAPS">PANGO_OT_TAG_DEFAULT_LANGUAGE</link>
#define             <link linkend="PANGO-OT-TAG-DEFAULT-SCRIPT:CAPS">PANGO_OT_TAG_DEFAULT_SCRIPT</link>
<link linkend="PangoOTInfo">PangoOTInfo</link>*        <link linkend="pango-ot-info-get">pango_ot_info_get</link>                   (<link linkend="FT-Face">FT_Face</link> face);
<link linkend="gboolean">gboolean</link>            <link linkend="pango-ot-info-find-script">pango_ot_info_find_script</link>           (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type,
                                                         <link linkend="PangoOTTag">PangoOTTag</link> script_tag,
                                                         <link linkend="guint">guint</link> *script_index);
<link linkend="gboolean">gboolean</link>            <link linkend="pango-ot-info-find-language">pango_ot_info_find_language</link>         (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type,
                                                         <link linkend="guint">guint</link> script_index,
                                                         <link linkend="PangoOTTag">PangoOTTag</link> language_tag,
                                                         <link linkend="guint">guint</link> *language_index,
                                                         <link linkend="guint">guint</link> *required_feature_index);
<link linkend="gboolean">gboolean</link>            <link linkend="pango-ot-info-find-feature">pango_ot_info_find_feature</link>          (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type,
                                                         <link linkend="PangoOTTag">PangoOTTag</link> feature_tag,
                                                         <link linkend="guint">guint</link> script_index,
                                                         <link linkend="guint">guint</link> language_index,
                                                         <link linkend="guint">guint</link> *feature_index);
<link linkend="PangoOTTag">PangoOTTag</link>*         <link linkend="pango-ot-info-list-scripts">pango_ot_info_list_scripts</link>          (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type);
<link linkend="PangoOTTag">PangoOTTag</link>*         <link linkend="pango-ot-info-list-languages">pango_ot_info_list_languages</link>        (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type,
                                                         <link linkend="guint">guint</link> script_index,
                                                         <link linkend="PangoOTTag">PangoOTTag</link> language_tag);
<link linkend="PangoOTTag">PangoOTTag</link>*         <link linkend="pango-ot-info-list-features">pango_ot_info_list_features</link>         (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type,
                                                         <link linkend="PangoOTTag">PangoOTTag</link> tag,
                                                         <link linkend="guint">guint</link> script_index,
                                                         <link linkend="guint">guint</link> language_index);
<link linkend="PangoOTBuffer">PangoOTBuffer</link>*      <link linkend="pango-ot-buffer-new">pango_ot_buffer_new</link>                 (<link linkend="PangoFcFont">PangoFcFont</link> *font);
<link linkend="void">void</link>                <link linkend="pango-ot-buffer-destroy">pango_ot_buffer_destroy</link>             (<link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer);
<link linkend="void">void</link>                <link linkend="pango-ot-buffer-clear">pango_ot_buffer_clear</link>               (<link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer);
<link linkend="void">void</link>                <link linkend="pango-ot-buffer-add-glyph">pango_ot_buffer_add_glyph</link>           (<link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer,
                                                         <link linkend="guint">guint</link> glyph,
                                                         <link linkend="guint">guint</link> properties,
                                                         <link linkend="guint">guint</link> cluster);
<link linkend="void">void</link>                <link linkend="pango-ot-buffer-set-rtl">pango_ot_buffer_set_rtl</link>             (<link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer,
                                                         <link linkend="gboolean">gboolean</link> rtl);
<link linkend="void">void</link>                <link linkend="pango-ot-buffer-set-zero-width-marks">pango_ot_buffer_set_zero_width_marks</link>
                                                        (<link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer,
                                                         <link linkend="gboolean">gboolean</link> zero_width_marks);
<link linkend="void">void</link>                <link linkend="pango-ot-buffer-get-glyphs">pango_ot_buffer_get_glyphs</link>          (const <link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer,
                                                         <link linkend="PangoOTGlyph">PangoOTGlyph</link> **glyphs,
                                                         <link linkend="int">int</link> *n_glyphs);
<link linkend="void">void</link>                <link linkend="pango-ot-buffer-output">pango_ot_buffer_output</link>              (const <link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer,
                                                         <link linkend="PangoGlyphString">PangoGlyphString</link> *glyphs);
const <link linkend="PangoOTRuleset">PangoOTRuleset</link>* <link linkend="pango-ot-ruleset-get-for-description">pango_ot_ruleset_get_for_description</link>
                                                        (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         const <link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link> *desc);
<link linkend="PangoOTRuleset">PangoOTRuleset</link>*     <link linkend="pango-ot-ruleset-new">pango_ot_ruleset_new</link>                (<link linkend="PangoOTInfo">PangoOTInfo</link> *info);
<link linkend="PangoOTRuleset">PangoOTRuleset</link>*     <link linkend="pango-ot-ruleset-new-for">pango_ot_ruleset_new_for</link>            (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         <link linkend="PangoScript">PangoScript</link> script,
                                                         <link linkend="PangoLanguage">PangoLanguage</link> *language);
<link linkend="PangoOTRuleset">PangoOTRuleset</link>*     <link linkend="pango-ot-ruleset-new-from-description">pango_ot_ruleset_new_from_description</link>
                                                        (<link linkend="PangoOTInfo">PangoOTInfo</link> *info,
                                                         const <link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link> *desc);
<link linkend="void">void</link>                <link linkend="pango-ot-ruleset-add-feature">pango_ot_ruleset_add_feature</link>        (<link linkend="PangoOTRuleset">PangoOTRuleset</link> *ruleset,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type,
                                                         <link linkend="guint">guint</link> feature_index,
                                                         <link linkend="gulong">gulong</link> property_bit);
<link linkend="gboolean">gboolean</link>            <link linkend="pango-ot-ruleset-maybe-add-feature">pango_ot_ruleset_maybe_add_feature</link>  (<link linkend="PangoOTRuleset">PangoOTRuleset</link> *ruleset,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type,
                                                         <link linkend="PangoOTTag">PangoOTTag</link> feature_tag,
                                                         <link linkend="gulong">gulong</link> property_bit);
<link linkend="guint">guint</link>               <link linkend="pango-ot-ruleset-maybe-add-features">pango_ot_ruleset_maybe_add_features</link> (<link linkend="PangoOTRuleset">PangoOTRuleset</link> *ruleset,
                                                         <link linkend="PangoOTTableType">PangoOTTableType</link> table_type,
                                                         const <link linkend="PangoOTFeatureMap">PangoOTFeatureMap</link> *features,
                                                         <link linkend="guint">guint</link> n_features);
<link linkend="guint">guint</link>               <link linkend="pango-ot-ruleset-get-feature-count">pango_ot_ruleset_get_feature_count</link>  (const <link linkend="PangoOTRuleset">PangoOTRuleset</link> *ruleset,
                                                         <link linkend="guint">guint</link> *n_gsub_features,
                                                         <link linkend="guint">guint</link> *n_gpos_features);
<link linkend="void">void</link>                <link linkend="pango-ot-ruleset-substitute">pango_ot_ruleset_substitute</link>         (const <link linkend="PangoOTRuleset">PangoOTRuleset</link> *ruleset,
                                                         <link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer);
<link linkend="void">void</link>                <link linkend="pango-ot-ruleset-position">pango_ot_ruleset_position</link>           (const <link linkend="PangoOTRuleset">PangoOTRuleset</link> *ruleset,
                                                         <link linkend="PangoOTBuffer">PangoOTBuffer</link> *buffer);
<link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link>* <link linkend="pango-ot-ruleset-description-copy">pango_ot_ruleset_description_copy</link>
                                                        (const <link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link> *desc);
<link linkend="gboolean">gboolean</link>            <link linkend="pango-ot-ruleset-description-equal">pango_ot_ruleset_description_equal</link>  (const <link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link> *desc1,
                                                         const <link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link> *desc2);
<link linkend="void">void</link>                <link linkend="pango-ot-ruleset-description-free">pango_ot_ruleset_description_free</link>   (<link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link> *desc);
<link linkend="guint">guint</link>               <link linkend="pango-ot-ruleset-description-hash">pango_ot_ruleset_description_hash</link>   (const <link linkend="PangoOTRulesetDescription">PangoOTRulesetDescription</link> *desc);
<link linkend="PangoOTTag">PangoOTTag</link>          <link linkend="pango-ot-tag-from-language">pango_ot_tag_from_language</link>          (<link linkend="PangoLanguage">PangoLanguage</link> *language);
<link linkend="PangoOTTag">PangoOTTag</link>          <link linkend="pango-ot-tag-from-script">pango_ot_tag_from_script</link>            (<link linkend="PangoScript">PangoScript</link> script);
<link linkend="PangoLanguage">PangoLanguage</link>*      <link linkend="pango-ot-tag-to-language">pango_ot_tag_to_language</link>            (<link linkend="PangoOTTag">PangoOTTag</link> language_tag);
<link linkend="PangoScript">PangoScript</link>         <link linkend="pango-ot-tag-to-script">pango_ot_tag_to_script</link>              (<link linkend="PangoOTTag">PangoOTTag</link> script_tag);
</synopsis>
</refsynopsisdiv>

<refsect1 id="pango-OpenType-Font-Handling.object-hierarchy" role="object_hierarchy">
<title role="object_hierarchy.title">Object Hierarchy</title>
<synopsis>
  <link linkend="GObject">GObject</link>
   +----PangoOTInfo
</synopsis>
<synopsis>
  <link linkend="GObject">GObject</link>
   +----PangoOTRuleset
</synopsis>

</refsect1>








<refsect1 id="pango-OpenType-Font-Handling.description" role="desc">
<title role="desc.title">Description</title>
<para>
Functions and macros in this section are used to implement the OpenType Layout
features and algorithms.  These are mostly useful when writing Fontconfig-based
shaping engines
</para>
</refsect1>

<refsect1 id="pango-OpenType-Font-Handling.details" role="details">
<title role="details.title">Details</title>
<refsect2 id="PangoOTTag" role="typedef">
<title>PangoOTTag</title>
<indexterm zone="PangoOTTag"><primary>PangoOTTag</primary></indexterm><programlisting>typedef guint32 PangoOTTag;
</programlisting>
<para>
The <type>PangoOTTag</type> typedef is used to represent TrueType and OpenType
four letter tags inside Pango. Use <link linkend="PANGO-OT-TAG-MAKE:CAPS"><function>PANGO_OT_TAG_MAKE()</function></link>
or <link linkend="PANGO-OT-TAG-MAKE-FROM-STRING:CAPS"><function>PANGO_OT_TAG_MAKE_FROM_STRING()</function></link> macros to create <type>PangoOTTag</type>s manually.
</para></refsect2>
<refsect2 id="PangoOTInfo-struct" role="struct">
<title>PangoOTInfo</title>
<indexterm zone="PangoOTInfo-struct"><primary>PangoOTInfo</primary></indexterm><programlisting>typedef struct _PangoOTInfo PangoOTInfo;</programlisting>
<para>
The <link linkend="PangoOTInfo"><type>PangoOTInfo</type></link> struct contains the various 
tables associated with an OpenType font. It contains only private fields and
should only be accessed via the <function>pango_ot_info_*</function> functions
which are documented below. To obtain a <link linkend="PangoOTInfo"><type>PangoOTInfo</type></link>,
use <link linkend="pango-ot-info-new"><function>pango_ot_info_new()</function></link>.
</para></refsect2>
<refsect2 id="PangoOTBuffer" role="struct">
<title>PangoOTBuffer</title>
<indexterm zone="PangoOTBuffer"><primary>PangoOTBuffer</primary></indexterm><programlisting>typedef struct _PangoOTBuffer PangoOTBuffer;</programlisting>
<para>
The <link linkend="PangoOTBuffer"><type>PangoOTBuffer</type></link> structure is used to store strings of glyphs associated
with a <link linkend="PangoFcFont"><type>PangoFcFont</type></link>, suitable for OpenType layout processing.  It contains
only private fields and should only be accessed via the
<function>pango_ot_buffer_*</function> functions which are documented below.
To obtain a <link linkend="PangoOTBuffer"><type>PangoOTBuffer</type></link>, use <link linkend="pango-ot-buffer-new"><function>pango_ot_buffer_new()</function></link>.
</para></refsect2>
<refsect2 id="PangoOTGlyph" role="struct">
<title>PangoOTGlyph</title>
<indexterm zone="PangoOTGlyph"><primary>PangoOTGlyph</primary></indexterm><programlisting>typedef struct {
  guint    glyph;
  guint    properties;
  guint    cluster;
  gushort  component;