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<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table>
<h1>FreeType-2.5.5 API Reference</h1>
<h1>The auto-hinter</h1>
<h2>Synopsis</h2>
<table class="synopsis">
<tr><td><a href="#glyph-to-script-map">glyph-to-script-map</a></td><td><a href="#default-script">default-script</a></td></tr>
<tr><td><a href="#FT_AUTOHINTER_SCRIPT_XXX">FT_AUTOHINTER_SCRIPT_XXX</a></td><td><a href="#increase-x-height">increase-x-height</a></td></tr>
<tr><td><a href="#FT_Prop_GlyphToScriptMap">FT_Prop_GlyphToScriptMap</a></td><td><a href="#FT_Prop_IncreaseXHeight">FT_Prop_IncreaseXHeight</a></td></tr>
<tr><td><a href="#fallback-script">fallback-script</a></td><td></td></tr>
</table>
<p>While FreeType's auto-hinter doesn't expose API functions by itself, it is possible to control its behaviour with <a href="ft2-module_management.html#FT_Property_Set">FT_Property_Set</a> and <a href="ft2-module_management.html#FT_Property_Get">FT_Property_Get</a>. The following lists the available properties together with the necessary macros and structures.</p>
<p>Note that the auto-hinter's module name is ‘autofitter’ for historical reasons.</p>
<div class="section">
<h3 id="glyph-to-script-map">glyph-to-script-map</h3>
<p><b>Experimental</b> <b>only</b></p>
<p>The auto-hinter provides various script modules to hint glyphs. Examples of supported scripts are Latin or CJK. Before a glyph is auto-hinted, the Unicode character map of the font gets examined, and the script is then determined based on Unicode character ranges, see below.</p>
<p>OpenType fonts, however, often provide much more glyphs than character codes (small caps, superscripts, ligatures, swashes, etc.), to be controlled by so-called ‘features’. Handling OpenType features can be quite complicated and thus needs a separate library on top of FreeType.</p>
<p>The mapping between glyph indices and scripts (in the auto-hinter sense, see the <a href="ft2-auto_hinter.html#FT_AUTOHINTER_SCRIPT_XXX">FT_AUTOHINTER_SCRIPT_XXX</a> values) is stored as an array with ‘num_glyphs’ elements, as found in the font's <a href="ft2-base_interface.html#FT_Face">FT_Face</a> structure. The ‘glyph-to-script-map’ property returns a pointer to this array, which can be modified as needed. Note that the modification should happen before the first glyph gets processed by the auto-hinter so that the global analysis of the font shapes actually uses the modified mapping.</p>
<p>The following example code demonstrates how to access it (omitting the error handling).</p>
<pre class="colored">
FT_Library library;
FT_Face face;
FT_Prop_GlyphToScriptMap prop;
FT_Init_FreeType( &library );
FT_New_Face( library, "foo.ttf", 0, &face );
prop.face = face;
FT_Property_Get( library, "autofitter",
"glyph-to-script-map", &prop );
// adjust `prop.map' as needed right here
FT_Load_Glyph( face, ..., FT_LOAD_FORCE_AUTOHINT );
</pre>
<hr>
<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="middle">[<a href="#">Top</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table></div>
<div class="section">
<h3 id="FT_AUTOHINTER_SCRIPT_XXX">FT_AUTOHINTER_SCRIPT_XXX</h3>
<p>Defined in FT_AUTOHINTER_H (ftautoh.h).</p>
<pre>
#define <a href="ft2-auto_hinter.html#FT_AUTOHINTER_SCRIPT_NONE">FT_AUTOHINTER_SCRIPT_NONE</a> 0
#define <a href="ft2-auto_hinter.html#FT_AUTOHINTER_SCRIPT_LATIN">FT_AUTOHINTER_SCRIPT_LATIN</a> 1
#define <a href="ft2-auto_hinter.html#FT_AUTOHINTER_SCRIPT_CJK">FT_AUTOHINTER_SCRIPT_CJK</a> 2
#define <a href="ft2-auto_hinter.html#FT_AUTOHINTER_SCRIPT_INDIC">FT_AUTOHINTER_SCRIPT_INDIC</a> 3
</pre>
<p><b>Experimental</b> <b>only</b></p>
<p>A list of constants used for the <a href="ft2-auto_hinter.html#glyph-to-script-map">glyph-to-script-map</a> property to specify the script submodule the auto-hinter should use for hinting a particular glyph.</p>
<h4>values</h4>
<table class="fields">
<tr><td class="val" id="FT_AUTOHINTER_SCRIPT_NONE">FT_AUTOHINTER_SCRIPT_NONE</td><td class="desc">
<p>Don't auto-hint this glyph.</p>
</td></tr>
<tr><td class="val" id="FT_AUTOHINTER_SCRIPT_LATIN">FT_AUTOHINTER_SCRIPT_LATIN</td><td class="desc">
<p>Apply the latin auto-hinter. For the auto-hinter, ‘latin’ is a very broad term, including Cyrillic and Greek also since characters from those scripts share the same design constraints.</p>
<p>By default, characters from the following Unicode ranges are assigned to this submodule.</p>
<pre class="colored">
U+0020 - U+007F // Basic Latin (no control characters)
U+00A0 - U+00FF // Latin-1 Supplement (no control characters)
U+0100 - U+017F // Latin Extended-A
U+0180 - U+024F // Latin Extended-B
U+0250 - U+02AF // IPA Extensions
U+02B0 - U+02FF // Spacing Modifier Letters
U+0300 - U+036F // Combining Diacritical Marks
U+0370 - U+03FF // Greek and Coptic
U+0400 - U+04FF // Cyrillic
U+0500 - U+052F // Cyrillic Supplement
U+1D00 - U+1D7F // Phonetic Extensions
U+1D80 - U+1DBF // Phonetic Extensions Supplement
U+1DC0 - U+1DFF // Combining Diacritical Marks Supplement
U+1E00 - U+1EFF // Latin Extended Additional
U+1F00 - U+1FFF // Greek Extended
U+2000 - U+206F // General Punctuation
U+2070 - U+209F // Superscripts and Subscripts
U+20A0 - U+20CF // Currency Symbols
U+2150 - U+218F // Number Forms
U+2460 - U+24FF // Enclosed Alphanumerics
U+2C60 - U+2C7F // Latin Extended-C
U+2DE0 - U+2DFF // Cyrillic Extended-A
U+2E00 - U+2E7F // Supplemental Punctuation
U+A640 - U+A69F // Cyrillic Extended-B
U+A720 - U+A7FF // Latin Extended-D
U+FB00 - U+FB06 // Alphab. Present. Forms (Latin Ligatures)
U+1D400 - U+1D7FF // Mathematical Alphanumeric Symbols
U+1F100 - U+1F1FF // Enclosed Alphanumeric Supplement
</pre>
<p></p>
</td></tr>
<tr><td class="val" id="FT_AUTOHINTER_SCRIPT_CJK">FT_AUTOHINTER_SCRIPT_CJK</td><td class="desc">
<p>Apply the CJK auto-hinter, covering Chinese, Japanese, Korean, old Vietnamese, and some other scripts.</p>
<p>By default, characters from the following Unicode ranges are assigned to this submodule.</p>
<pre class="colored">
U+1100 - U+11FF // Hangul Jamo
U+2E80 - U+2EFF // CJK Radicals Supplement
U+2F00 - U+2FDF // Kangxi Radicals
U+2FF0 - U+2FFF // Ideographic Description Characters
U+3000 - U+303F // CJK Symbols and Punctuation
U+3040 - U+309F // Hiragana
U+30A0 - U+30FF // Katakana
U+3100 - U+312F // Bopomofo
U+3130 - U+318F // Hangul Compatibility Jamo
U+3190 - U+319F // Kanbun
U+31A0 - U+31BF // Bopomofo Extended
U+31C0 - U+31EF // CJK Strokes
U+31F0 - U+31FF // Katakana Phonetic Extensions
U+3200 - U+32FF // Enclosed CJK Letters and Months
U+3300 - U+33FF // CJK Compatibility
U+3400 - U+4DBF // CJK Unified Ideographs Extension A
U+4DC0 - U+4DFF // Yijing Hexagram Symbols
U+4E00 - U+9FFF // CJK Unified Ideographs
U+A960 - U+A97F // Hangul Jamo Extended-A
U+AC00 - U+D7AF // Hangul Syllables
U+D7B0 - U+D7FF // Hangul Jamo Extended-B
U+F900 - U+FAFF // CJK Compatibility Ideographs
U+FE10 - U+FE1F // Vertical forms
U+FE30 - U+FE4F // CJK Compatibility Forms
U+FF00 - U+FFEF // Halfwidth and Fullwidth Forms
U+1B000 - U+1B0FF // Kana Supplement
U+1D300 - U+1D35F // Tai Xuan Hing Symbols
U+1F200 - U+1F2FF // Enclosed Ideographic Supplement
U+20000 - U+2A6DF // CJK Unified Ideographs Extension B
U+2A700 - U+2B73F // CJK Unified Ideographs Extension C
U+2B740 - U+2B81F // CJK Unified Ideographs Extension D
U+2F800 - U+2FA1F // CJK Compatibility Ideographs Supplement
</pre>
<p></p>
</td></tr>
<tr><td class="val" id="FT_AUTOHINTER_SCRIPT_INDIC">FT_AUTOHINTER_SCRIPT_INDIC</td><td class="desc">
<p>Apply the indic auto-hinter, covering all major scripts from the Indian sub-continent and some other related scripts like Thai, Lao, or Tibetan.</p>
<p>By default, characters from the following Unicode ranges are assigned to this submodule.</p>
<pre class="colored">
U+0900 - U+0DFF // Indic Range
U+0F00 - U+0FFF // Tibetan
U+1900 - U+194F // Limbu
U+1B80 - U+1BBF // Sundanese
U+1C80 - U+1CDF // Meetei Mayak
U+A800 - U+A82F // Syloti Nagri
U+11800 - U+118DF // Sharada
</pre>
<p>Note that currently Indic support is rudimentary only, missing blue zone support.</p>
</td></tr>
</table>
<hr>
<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="middle">[<a href="#">Top</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table></div>
<div class="section">
<h3 id="FT_Prop_GlyphToScriptMap">FT_Prop_GlyphToScriptMap</h3>
<p>Defined in FT_AUTOHINTER_H (ftautoh.h).</p>
<pre>
<span class="keyword">typedef</span> <span class="keyword">struct</span> FT_Prop_GlyphToScriptMap_
{
<a href="ft2-base_interface.html#FT_Face">FT_Face</a> face;
<a href="ft2-basic_types.html#FT_Byte">FT_Byte</a>* map;
} <b>FT_Prop_GlyphToScriptMap</b>;
</pre>
<p><b>Experimental</b> <b>only</b></p>
<p>The data exchange structure for the <a href="ft2-auto_hinter.html#glyph-to-script-map">glyph-to-script-map</a> property.</p>
<hr>
<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="middle">[<a href="#">Top</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table></div>
<div class="section">
<h3 id="fallback-script">fallback-script</h3>
<p><b>Experimental</b> <b>only</b></p>
<p>If no auto-hinter script module can be assigned to a glyph, a fallback script gets assigned to it (see also the <a href="ft2-auto_hinter.html#glyph-to-script-map">glyph-to-script-map</a> property). By default, this is <a href="ft2-auto_hinter.html#FT_AUTOHINTER_SCRIPT_XXX">FT_AUTOHINTER_SCRIPT_CJK</a>. Using the ‘fallback-script’ property, this fallback value can be changed.</p>
<pre class="colored">
FT_Library library;
FT_UInt fallback_script = FT_AUTOHINTER_SCRIPT_NONE;
FT_Init_FreeType( &library );
FT_Property_Set( library, "autofitter",
"fallback-script", &fallback_script );
</pre>
<h4>note</h4>
<p>This property can be used with <a href="ft2-module_management.html#FT_Property_Get">FT_Property_Get</a> also.</p>
<p>It's important to use the right timing for changing this value: The creation of the glyph-to-script map that eventually uses the fallback script value gets triggered either by setting or reading a face-specific property like <a href="ft2-auto_hinter.html#glyph-to-script-map">glyph-to-script-map</a>, or by auto-hinting any glyph from that face. In particular, if you have already created an <a href="ft2-base_interface.html#FT_Face">FT_Face</a> structure but not loaded any glyph (using the auto-hinter), a change of the fallback script will affect this face.</p>
<hr>
<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="middle">[<a href="#">Top</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table></div>
<div class="section">
<h3 id="default-script">default-script</h3>
<p><b>Experimental</b> <b>only</b></p>
<p>If Freetype gets compiled with FT_CONFIG_OPTION_USE_HARFBUZZ to make the HarfBuzz library access OpenType features for getting better glyph coverages, this property sets the (auto-fitter) script to be used for the default (OpenType) script data of a font's GSUB table. Features for the default script are intended for all scripts not explicitly handled in GSUB; an example is a ‘dlig’ feature, containing the combination of the characters ‘T’, ‘E’, and ‘L’ to form a ‘TEL’ ligature.</p>
<p>By default, this is <a href="ft2-auto_hinter.html#FT_AUTOHINTER_SCRIPT_XXX">FT_AUTOHINTER_SCRIPT_LATIN</a>. Using the ‘default-script’ property, this default value can be changed.</p>
<pre class="colored">
FT_Library library;
FT_UInt default_script = FT_AUTOHINTER_SCRIPT_NONE;
FT_Init_FreeType( &library );
FT_Property_Set( library, "autofitter",
"default-script", &default_script );
</pre>
<h4>note</h4>
<p>This property can be used with <a href="ft2-module_management.html#FT_Property_Get">FT_Property_Get</a> also.</p>
<p>It's important to use the right timing for changing this value: The creation of the glyph-to-script map that eventually uses the default script value gets triggered either by setting or reading a face-specific property like <a href="ft2-auto_hinter.html#glyph-to-script-map">glyph-to-script-map</a>, or by auto-hinting any glyph from that face. In particular, if you have already created an <a href="ft2-base_interface.html#FT_Face">FT_Face</a> structure but not loaded any glyph (using the auto-hinter), a change of the default script will affect this face.</p>
<hr>
<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="middle">[<a href="#">Top</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table></div>
<div class="section">
<h3 id="increase-x-height">increase-x-height</h3>
<p>For ppem values in the range 6 <= ppem <= ‘increase-x-height’, round up the font's x height much more often than normally. If the value is set to 0, which is the default, this feature is switched off. Use this property to improve the legibility of small font sizes if necessary.</p>
<pre class="colored">
FT_Library library;
FT_Face face;
FT_Prop_IncreaseXHeight prop;
FT_Init_FreeType( &library );
FT_New_Face( library, "foo.ttf", 0, &face );
FT_Set_Char_Size( face, 10 * 64, 0, 72, 0 );
prop.face = face;
prop.limit = 14;
FT_Property_Set( library, "autofitter",
"increase-x-height", &prop );
</pre>
<h4>note</h4>
<p>This property can be used with <a href="ft2-module_management.html#FT_Property_Get">FT_Property_Get</a> also.</p>
<p>Set this value right after calling <a href="ft2-base_interface.html#FT_Set_Char_Size">FT_Set_Char_Size</a>, but before loading any glyph (using the auto-hinter).</p>
<hr>
<table class="index-toc-link"><tr><td class="left">[<a href="ft2-index.html">Index</a>]</td><td class="middle">[<a href="#">Top</a>]</td><td class="right">[<a href="ft2-toc.html">TOC</a>]</td></tr></table></div>
<div class="section">
<h3 id="FT_Prop_IncreaseXHeight">FT_Prop_IncreaseXHeight</h3>
<p>Defined in FT_AUTOHINTER_H (ftautoh.h).</p>
<pre>
<span class="keyword">typedef</span> <span class="keyword">struct</span> FT_Prop_IncreaseXHeight_
{
<a href="ft2-base_interface.html#FT_Face">FT_Face</a> face;
<a href="ft2-basic_types.html#FT_UInt">FT_UInt</a> limit;
} <b>FT_Prop_IncreaseXHeight</b>;
</pre>
<p>The data exchange structure for the <a href="ft2-auto_hinter.html#increase-x-height">increase-x-height</a> property.</p>
<hr>
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