src/third_party/freetype2/docs/reference/ft2-quick_advance.html - cobalt - Git at Google

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 <h1>FreeType-2.6.2 API Reference</h1>

 <h1 id="quick_advance">Quick retrieval of advance values</h1>
 <h2>Synopsis</h2>
 <table class="synopsis">
 <tr><td><a href="#FT_Get_Advance">FT_Get_Advance</a></td><td>&nbsp;</td></tr>
 <tr><td><a href="#FT_Get_Advances">FT_Get_Advances</a></td><td><a href="#FT_ADVANCE_FLAG_FAST_ONLY">FT_ADVANCE_FLAG_FAST_ONLY</a></td></tr>
 </table>


 <p>This section contains functions to quickly extract advance values without handling glyph outlines, if possible.</p>

 <div class="section">
 <h3 id="FT_Get_Advance">FT_Get_Advance</h3>
 <p>Defined in FT_ADVANCES_H (freetype/ftadvanc.h).</p>
 <pre>
   FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
   <b>FT_Get_Advance</b>( <a href="ft2-base_interface.html#FT_Face">FT_Face</a>    face,
                   <a href="ft2-basic_types.html#FT_UInt">FT_UInt</a>    gindex,
                   <a href="ft2-basic_types.html#FT_Int32">FT_Int32</a>   load_flags,
                   <a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a>  *padvance );
 </pre>

 <p>Retrieve the advance value of a given glyph outline in an <a href="ft2-base_interface.html#FT_Face">FT_Face</a>.</p>

 <h4>input</h4>
 <table class="fields">
 <tr><td class="val" id="face">face</td><td class="desc">
 <p>The source <a href="ft2-base_interface.html#FT_Face">FT_Face</a> handle.</p>
 </td></tr>
 <tr><td class="val" id="gindex">gindex</td><td class="desc">
 <p>The glyph index.</p>
 </td></tr>
 <tr><td class="val" id="load_flags">load_flags</td><td class="desc">
 <p>A set of bit flags similar to those used when calling <a href="ft2-base_interface.html#FT_Load_Glyph">FT_Load_Glyph</a>, used to determine what kind of advances you need.</p>
 </td></tr>
 </table>

 <h4>output</h4>
 <table class="fields">
 <tr><td class="val" id="padvance">padvance</td><td class="desc">
 <p>The advance value. If scaling is performed (based on the value of &lsquo;load_flags&rsquo;), the advance value is in 16.16 format. Otherwise, it is in font units.</p>
 <p>If <a href="ft2-base_interface.html#FT_LOAD_XXX">FT_LOAD_VERTICAL_LAYOUT</a> is set, this is the vertical advance corresponding to a vertical layout. Otherwise, it is the horizontal advance in a horizontal layout.</p>
 </td></tr>
 </table>

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

 <h4>note</h4>
 <p>This function may fail if you use <a href="ft2-quick_advance.html#FT_ADVANCE_FLAG_FAST_ONLY">FT_ADVANCE_FLAG_FAST_ONLY</a> and if the corresponding font backend doesn't have a quick way to retrieve the advances.</p>
 <p>A scaled advance is returned in 16.16 format but isn't transformed by the affine transformation specified by <a href="ft2-base_interface.html#FT_Set_Transform">FT_Set_Transform</a>.</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_Get_Advances">FT_Get_Advances</h3>
 <p>Defined in FT_ADVANCES_H (freetype/ftadvanc.h).</p>
 <pre>
   FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
   <b>FT_Get_Advances</b>( <a href="ft2-base_interface.html#FT_Face">FT_Face</a>    face,
                    <a href="ft2-basic_types.html#FT_UInt">FT_UInt</a>    start,
                    <a href="ft2-basic_types.html#FT_UInt">FT_UInt</a>    count,
                    <a href="ft2-basic_types.html#FT_Int32">FT_Int32</a>   load_flags,
                    <a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a>  *padvances );
 </pre>

 <p>Retrieve the advance values of several glyph outlines in an <a href="ft2-base_interface.html#FT_Face">FT_Face</a>.</p>

 <h4>input</h4>
 <table class="fields">
 <tr><td class="val" id="face">face</td><td class="desc">
 <p>The source <a href="ft2-base_interface.html#FT_Face">FT_Face</a> handle.</p>
 </td></tr>
 <tr><td class="val" id="start">start</td><td class="desc">
 <p>The first glyph index.</p>
 </td></tr>
 <tr><td class="val" id="count">count</td><td class="desc">
 <p>The number of advance values you want to retrieve.</p>
 </td></tr>
 <tr><td class="val" id="load_flags">load_flags</td><td class="desc">
 <p>A set of bit flags similar to those used when calling <a href="ft2-base_interface.html#FT_Load_Glyph">FT_Load_Glyph</a>.</p>
 </td></tr>
 </table>

 <h4>output</h4>
 <table class="fields">
 <tr><td class="val" id="padvance">padvance</td><td class="desc">
 <p>The advance values. This array, to be provided by the caller, must contain at least &lsquo;count&rsquo; elements.</p>
 <p>If scaling is performed (based on the value of &lsquo;load_flags&rsquo;), the advance values are in 16.16 format. Otherwise, they are in font units.</p>
 <p>If <a href="ft2-base_interface.html#FT_LOAD_XXX">FT_LOAD_VERTICAL_LAYOUT</a> is set, these are the vertical advances corresponding to a vertical layout. Otherwise, they are the horizontal advances in a horizontal layout.</p>
 </td></tr>
 </table>

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

 <h4>note</h4>
 <p>This function may fail if you use <a href="ft2-quick_advance.html#FT_ADVANCE_FLAG_FAST_ONLY">FT_ADVANCE_FLAG_FAST_ONLY</a> and if the corresponding font backend doesn't have a quick way to retrieve the advances.</p>
 <p>Scaled advances are returned in 16.16 format but aren't transformed by the affine transformation specified by <a href="ft2-base_interface.html#FT_Set_Transform">FT_Set_Transform</a>.</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_ADVANCE_FLAG_FAST_ONLY">FT_ADVANCE_FLAG_FAST_ONLY</h3>
 <p>Defined in FT_ADVANCES_H (freetype/ftadvanc.h).</p>
 <pre>
 #define <b>FT_ADVANCE_FLAG_FAST_ONLY</b>  0x20000000L
 </pre>

 <p>A bit-flag to be OR-ed with the &lsquo;flags&rsquo; parameter of the <a href="ft2-quick_advance.html#FT_Get_Advance">FT_Get_Advance</a> and <a href="ft2-quick_advance.html#FT_Get_Advances">FT_Get_Advances</a> functions.</p>
 <p>If set, it indicates that you want these functions to fail if the corresponding hinting mode or font driver doesn't allow for very quick advance computation.</p>
 <p>Typically, glyphs that are either unscaled, unhinted, bitmapped, or light-hinted can have their advance width computed very quickly.</p>
 <p>Normal and bytecode hinted modes that require loading, scaling, and hinting of the glyph outline, are extremely slow by comparison.</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>

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	<h1>FreeType-2.6.2 API Reference</h1>

	<h1 id="quick_advance">Quick retrieval of advance values</h1>
	<h2>Synopsis</h2>
	<table class="synopsis">
	<tr><td><a href="#FT_Get_Advance">FT_Get_Advance</a></td><td> </td></tr>
	<tr><td><a href="#FT_Get_Advances">FT_Get_Advances</a></td><td><a href="#FT_ADVANCE_FLAG_FAST_ONLY">FT_ADVANCE_FLAG_FAST_ONLY</a></td></tr>
	</table>


	<p>This section contains functions to quickly extract advance values without handling glyph outlines, if possible.</p>

	<div class="section">
	<h3 id="FT_Get_Advance">FT_Get_Advance</h3>
	<p>Defined in FT_ADVANCES_H (freetype/ftadvanc.h).</p>
	<pre>
	FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
	<b>FT_Get_Advance</b>( <a href="ft2-base_interface.html#FT_Face">FT_Face</a> face,
	<a href="ft2-basic_types.html#FT_UInt">FT_UInt</a> gindex,
	<a href="ft2-basic_types.html#FT_Int32">FT_Int32</a> load_flags,
	<a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a> *padvance );
	</pre>

	<p>Retrieve the advance value of a given glyph outline in an <a href="ft2-base_interface.html#FT_Face">FT_Face</a>.</p>

	<h4>input</h4>
	<table class="fields">
	<tr><td class="val" id="face">face</td><td class="desc">
	<p>The source <a href="ft2-base_interface.html#FT_Face">FT_Face</a> handle.</p>
	</td></tr>
	<tr><td class="val" id="gindex">gindex</td><td class="desc">
	<p>The glyph index.</p>
	</td></tr>
	<tr><td class="val" id="load_flags">load_flags</td><td class="desc">
	<p>A set of bit flags similar to those used when calling <a href="ft2-base_interface.html#FT_Load_Glyph">FT_Load_Glyph</a>, used to determine what kind of advances you need.</p>
	</td></tr>
	</table>

	<h4>output</h4>
	<table class="fields">
	<tr><td class="val" id="padvance">padvance</td><td class="desc">
	<p>The advance value. If scaling is performed (based on the value of ‘load_flags’), the advance value is in 16.16 format. Otherwise, it is in font units.</p>
	<p>If <a href="ft2-base_interface.html#FT_LOAD_XXX">FT_LOAD_VERTICAL_LAYOUT</a> is set, this is the vertical advance corresponding to a vertical layout. Otherwise, it is the horizontal advance in a horizontal layout.</p>
	</td></tr>
	</table>

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

	<h4>note</h4>
	<p>This function may fail if you use <a href="ft2-quick_advance.html#FT_ADVANCE_FLAG_FAST_ONLY">FT_ADVANCE_FLAG_FAST_ONLY</a> and if the corresponding font backend doesn't have a quick way to retrieve the advances.</p>
	<p>A scaled advance is returned in 16.16 format but isn't transformed by the affine transformation specified by <a href="ft2-base_interface.html#FT_Set_Transform">FT_Set_Transform</a>.</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_Get_Advances">FT_Get_Advances</h3>
	<p>Defined in FT_ADVANCES_H (freetype/ftadvanc.h).</p>
	<pre>
	FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
	<b>FT_Get_Advances</b>( <a href="ft2-base_interface.html#FT_Face">FT_Face</a> face,
	<a href="ft2-basic_types.html#FT_UInt">FT_UInt</a> start,
	<a href="ft2-basic_types.html#FT_UInt">FT_UInt</a> count,
	<a href="ft2-basic_types.html#FT_Int32">FT_Int32</a> load_flags,
	<a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a> *padvances );
	</pre>

	<p>Retrieve the advance values of several glyph outlines in an <a href="ft2-base_interface.html#FT_Face">FT_Face</a>.</p>

	<h4>input</h4>
	<table class="fields">
	<tr><td class="val" id="face">face</td><td class="desc">
	<p>The source <a href="ft2-base_interface.html#FT_Face">FT_Face</a> handle.</p>
	</td></tr>
	<tr><td class="val" id="start">start</td><td class="desc">
	<p>The first glyph index.</p>
	</td></tr>
	<tr><td class="val" id="count">count</td><td class="desc">
	<p>The number of advance values you want to retrieve.</p>
	</td></tr>
	<tr><td class="val" id="load_flags">load_flags</td><td class="desc">
	<p>A set of bit flags similar to those used when calling <a href="ft2-base_interface.html#FT_Load_Glyph">FT_Load_Glyph</a>.</p>
	</td></tr>
	</table>

	<h4>output</h4>
	<table class="fields">
	<tr><td class="val" id="padvance">padvance</td><td class="desc">
	<p>The advance values. This array, to be provided by the caller, must contain at least ‘count’ elements.</p>
	<p>If scaling is performed (based on the value of ‘load_flags’), the advance values are in 16.16 format. Otherwise, they are in font units.</p>
	<p>If <a href="ft2-base_interface.html#FT_LOAD_XXX">FT_LOAD_VERTICAL_LAYOUT</a> is set, these are the vertical advances corresponding to a vertical layout. Otherwise, they are the horizontal advances in a horizontal layout.</p>
	</td></tr>
	</table>

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

	<h4>note</h4>
	<p>This function may fail if you use <a href="ft2-quick_advance.html#FT_ADVANCE_FLAG_FAST_ONLY">FT_ADVANCE_FLAG_FAST_ONLY</a> and if the corresponding font backend doesn't have a quick way to retrieve the advances.</p>
	<p>Scaled advances are returned in 16.16 format but aren't transformed by the affine transformation specified by <a href="ft2-base_interface.html#FT_Set_Transform">FT_Set_Transform</a>.</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_ADVANCE_FLAG_FAST_ONLY">FT_ADVANCE_FLAG_FAST_ONLY</h3>
	<p>Defined in FT_ADVANCES_H (freetype/ftadvanc.h).</p>
	<pre>
	#define <b>FT_ADVANCE_FLAG_FAST_ONLY</b> 0x20000000L
	</pre>

	<p>A bit-flag to be OR-ed with the ‘flags’ parameter of the <a href="ft2-quick_advance.html#FT_Get_Advance">FT_Get_Advance</a> and <a href="ft2-quick_advance.html#FT_Get_Advances">FT_Get_Advances</a> functions.</p>
	<p>If set, it indicates that you want these functions to fail if the corresponding hinting mode or font driver doesn't allow for very quick advance computation.</p>
	<p>Typically, glyphs that are either unscaled, unhinted, bitmapped, or light-hinted can have their advance width computed very quickly.</p>
	<p>Normal and bytecode hinted modes that require loading, scaling, and hinting of the glyph outline, are extremely slow by comparison.</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>

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