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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-2.9.1 API Reference</h1>

<h1 id="ot_validation">OpenType Validation</h1>
<h2>Synopsis</h2>
<table class="synopsis">
<tr><td><a href="#FT_OpenType_Validate">FT_OpenType_Validate</a></td><td>&nbsp;</td><td></td></tr>
<tr><td><a href="#FT_OpenType_Free">FT_OpenType_Free</a></td><td><a href="#FT_VALIDATE_OTXXX">FT_VALIDATE_OTXXX</a></td><td></td></tr>
</table>

<p>This section contains the declaration of functions to validate some OpenType tables (BASE, GDEF, GPOS, GSUB, JSTF, MATH).</p>

<div class="section">
<h3 id="FT_OpenType_Validate">FT_OpenType_Validate</h3>
<p>Defined in FT_OPENTYPE_VALIDATE_H (freetype/ftotval.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_OpenType_Validate</b>( <a href="ft2-base_interface.html#FT_Face">FT_Face</a>    face,
                        <a href="ft2-basic_types.html#FT_UInt">FT_UInt</a>    validation_flags,
                        <a href="ft2-basic_types.html#FT_Bytes">FT_Bytes</a>  *BASE_table,
                        <a href="ft2-basic_types.html#FT_Bytes">FT_Bytes</a>  *GDEF_table,
                        <a href="ft2-basic_types.html#FT_Bytes">FT_Bytes</a>  *GPOS_table,
                        <a href="ft2-basic_types.html#FT_Bytes">FT_Bytes</a>  *GSUB_table,
                        <a href="ft2-basic_types.html#FT_Bytes">FT_Bytes</a>  *JSTF_table );
</pre>

<p>Validate various OpenType tables to assure that all offsets and indices are valid. The idea is that a higher-level library that actually does the text layout can access those tables without error checking (which can be quite time consuming).</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="face">face</td><td class="desc">
<p>A handle to the input face.</p>
</td></tr>
<tr><td class="val" id="validation_flags">validation_flags</td><td class="desc">
<p>A bit field that specifies the tables to be validated. See <a href="ft2-ot_validation.html#FT_VALIDATE_OTXXX">FT_VALIDATE_OTXXX</a> for possible values.</p>
</td></tr>
</table>

<h4>output</h4>
<table class="fields">
<tr><td class="val" id="BASE_table">BASE_table</td><td class="desc">
<p>A pointer to the BASE table.</p>
</td></tr>
<tr><td class="val" id="GDEF_table">GDEF_table</td><td class="desc">
<p>A pointer to the GDEF table.</p>
</td></tr>
<tr><td class="val" id="GPOS_table">GPOS_table</td><td class="desc">
<p>A pointer to the GPOS table.</p>
</td></tr>
<tr><td class="val" id="GSUB_table">GSUB_table</td><td class="desc">
<p>A pointer to the GSUB table.</p>
</td></tr>
<tr><td class="val" id="JSTF_table">JSTF_table</td><td class="desc">
<p>A pointer to the JSTF table.</p>
</td></tr>
</table>

<h4>return</h4>
<p>FreeType error code. 0&nbsp;means success.</p>

<h4>note</h4>
<p>This function only works with OpenType fonts, returning an error otherwise.</p>
<p>After use, the application should deallocate the five tables with <a href="ft2-ot_validation.html#FT_OpenType_Free">FT_OpenType_Free</a>. A NULL value indicates that the table either doesn't exist in the font, or the application hasn't asked for validation.</p>

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<div class="section">
<h3 id="FT_OpenType_Free">FT_OpenType_Free</h3>
<p>Defined in FT_OPENTYPE_VALIDATE_H (freetype/ftotval.h).</p>
<pre>
  FT_EXPORT( <span class="keyword">void</span> )
  <b>FT_OpenType_Free</b>( <a href="ft2-base_interface.html#FT_Face">FT_Face</a>   face,
                    <a href="ft2-basic_types.html#FT_Bytes">FT_Bytes</a>  table );
</pre>

<p>Free the buffer allocated by OpenType validator.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="face">face</td><td class="desc">
<p>A handle to the input face.</p>
</td></tr>
<tr><td class="val" id="table">table</td><td class="desc">
<p>The pointer to the buffer that is allocated by <a href="ft2-ot_validation.html#FT_OpenType_Validate">FT_OpenType_Validate</a>.</p>
</td></tr>
</table>

<h4>note</h4>
<p>This function must be used to free the buffer allocated by <a href="ft2-ot_validation.html#FT_OpenType_Validate">FT_OpenType_Validate</a> only.</p>

<div class="section">
<h3 id="FT_VALIDATE_OTXXX">FT_VALIDATE_OTXXX</h3>
<p>Defined in FT_OPENTYPE_VALIDATE_H (freetype/ftotval.h).</p>
<pre>
#define <a href="ft2-ot_validation.html#FT_VALIDATE_BASE">FT_VALIDATE_BASE</a>  0x0100
#define <a href="ft2-ot_validation.html#FT_VALIDATE_GDEF">FT_VALIDATE_GDEF</a>  0x0200
#define <a href="ft2-ot_validation.html#FT_VALIDATE_GPOS">FT_VALIDATE_GPOS</a>  0x0400
#define <a href="ft2-ot_validation.html#FT_VALIDATE_GSUB">FT_VALIDATE_GSUB</a>  0x0800
#define <a href="ft2-ot_validation.html#FT_VALIDATE_JSTF">FT_VALIDATE_JSTF</a>  0x1000
#define <a href="ft2-ot_validation.html#FT_VALIDATE_MATH">FT_VALIDATE_MATH</a>  0x2000

#define <a href="ft2-ot_validation.html#FT_VALIDATE_OT">FT_VALIDATE_OT</a>  ( <a href="ft2-ot_validation.html#FT_VALIDATE_BASE">FT_VALIDATE_BASE</a> | \
                          <a href="ft2-ot_validation.html#FT_VALIDATE_GDEF">FT_VALIDATE_GDEF</a> | \
                          <a href="ft2-ot_validation.html#FT_VALIDATE_GPOS">FT_VALIDATE_GPOS</a> | \
                          <a href="ft2-ot_validation.html#FT_VALIDATE_GSUB">FT_VALIDATE_GSUB</a> | \
                          <a href="ft2-ot_validation.html#FT_VALIDATE_JSTF">FT_VALIDATE_JSTF</a> | \
                          <a href="ft2-ot_validation.html#FT_VALIDATE_MATH">FT_VALIDATE_MATH</a> )
</pre>

<p>A list of bit-field constants used with <a href="ft2-ot_validation.html#FT_OpenType_Validate">FT_OpenType_Validate</a> to indicate which OpenType tables should be validated.</p>

<h4>values</h4>
<table class="fields">
<tr><td class="val" id="FT_VALIDATE_BASE">FT_VALIDATE_BASE</td><td class="desc">
<p>Validate BASE table.</p>
</td></tr>
<tr><td class="val" id="FT_VALIDATE_GDEF">FT_VALIDATE_GDEF</td><td class="desc">
<p>Validate GDEF table.</p>
</td></tr>
<tr><td class="val" id="FT_VALIDATE_GPOS">FT_VALIDATE_GPOS</td><td class="desc">
<p>Validate GPOS table.</p>
</td></tr>
<tr><td class="val" id="FT_VALIDATE_GSUB">FT_VALIDATE_GSUB</td><td class="desc">
<p>Validate GSUB table.</p>
</td></tr>
<tr><td class="val" id="FT_VALIDATE_JSTF">FT_VALIDATE_JSTF</td><td class="desc">
<p>Validate JSTF table.</p>
</td></tr>
<tr><td class="val" id="FT_VALIDATE_MATH">FT_VALIDATE_MATH</td><td class="desc">
<p>Validate MATH table.</p>
</td></tr>
<tr><td class="val" id="FT_VALIDATE_OT">FT_VALIDATE_OT</td><td class="desc">
<p>Validate all OpenType tables (BASE, GDEF, GPOS, GSUB, JSTF, MATH).</p>
</td></tr>
</table>

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