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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="module_management">Module Management</h1>
<h2>Synopsis</h2>
<table class="synopsis">
<tr><td><a href="#FT_Module">FT_Module</a></td><td>&nbsp;</td></tr>
<tr><td><a href="#FT_Module_Constructor">FT_Module_Constructor</a></td><td><a href="#FT_New_Library">FT_New_Library</a></td></tr>
<tr><td><a href="#FT_Module_Destructor">FT_Module_Destructor</a></td><td><a href="#FT_Done_Library">FT_Done_Library</a></td></tr>
<tr><td><a href="#FT_Module_Requester">FT_Module_Requester</a></td><td><a href="#FT_Reference_Library">FT_Reference_Library</a></td></tr>
<tr><td><a href="#FT_Module_Class">FT_Module_Class</a></td><td>&nbsp;</td></tr>
<tr><td>&nbsp;</td><td><a href="#FT_Renderer">FT_Renderer</a></td></tr>
<tr><td><a href="#FT_Add_Module">FT_Add_Module</a></td><td><a href="#FT_Renderer_Class">FT_Renderer_Class</a></td></tr>
<tr><td><a href="#FT_Get_Module">FT_Get_Module</a></td><td>&nbsp;</td></tr>
<tr><td><a href="#FT_Remove_Module">FT_Remove_Module</a></td><td><a href="#FT_Get_Renderer">FT_Get_Renderer</a></td></tr>
<tr><td><a href="#FT_Add_Default_Modules">FT_Add_Default_Modules</a></td><td><a href="#FT_Set_Renderer">FT_Set_Renderer</a></td></tr>
<tr><td>&nbsp;</td><td>&nbsp;</td></tr>
<tr><td><a href="#FT_Property_Set">FT_Property_Set</a></td><td><a href="#FT_Set_Debug_Hook">FT_Set_Debug_Hook</a></td></tr>
<tr><td><a href="#FT_Property_Get">FT_Property_Get</a></td><td>&nbsp;</td></tr>
<tr><td><a href="#FT_Set_Default_Properties">FT_Set_Default_Properties</a></td><td><a href="#FT_Driver">FT_Driver</a></td></tr>
</table>

<p>The definitions below are used to manage modules within FreeType. Modules can be added, upgraded, and removed at runtime. Additionally, some module properties can be controlled also.</p>
<p>Here is a list of possible values of the &lsquo;module_name&rsquo; field in the <a href="ft2-module_management.html#FT_Module_Class">FT_Module_Class</a> structure.</p>
<pre class="colored">
  autofitter
  bdf
  cff
  gxvalid
  otvalid
  pcf
  pfr
  psaux
  pshinter
  psnames
  raster1
  sfnt
  smooth, smooth-lcd, smooth-lcdv
  truetype
  type1
  type42
  t1cid
  winfonts
</pre>
<p>Note that the FreeType Cache sub-system is not a FreeType module.</p>

<div class="section">
<h3 id="FT_Module">FT_Module</h3>
<p>Defined in FT_FREETYPE_H (freetype/freetype.h).</p>
<pre>
  <span class="keyword">typedef</span> <span class="keyword">struct</span> FT_ModuleRec_*  <b>FT_Module</b>;
</pre>

<p>A handle to a given FreeType module object. A module can be a font driver, a renderer, or anything else that provides services to the former.</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_Module_Constructor">FT_Module_Constructor</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  <span class="keyword">typedef</span> <a href="ft2-basic_types.html#FT_Error">FT_Error</a>
  (*<b>FT_Module_Constructor</b>)( <a href="ft2-module_management.html#FT_Module">FT_Module</a>  module );
</pre>

<p>A function used to initialize (not create) a new module object.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="module">module</td><td class="desc">
<p>The module to initialize.</p>
</td></tr>
</table>

<div class="section">
<h3 id="FT_Module_Destructor">FT_Module_Destructor</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  <span class="keyword">typedef</span> <span class="keyword">void</span>
  (*<b>FT_Module_Destructor</b>)( <a href="ft2-module_management.html#FT_Module">FT_Module</a>  module );
</pre>

<p>A function used to finalize (not destroy) a given module object.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="module">module</td><td class="desc">
<p>The module to finalize.</p>
</td></tr>
</table>

<div class="section">
<h3 id="FT_Module_Requester">FT_Module_Requester</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  <span class="keyword">typedef</span> FT_Module_Interface
  (*<b>FT_Module_Requester</b>)( <a href="ft2-module_management.html#FT_Module">FT_Module</a>    module,
                          <span class="keyword">const</span> <span class="keyword">char</span>*  name );
</pre>

<p>A function used to query a given module for a specific interface.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="module">module</td><td class="desc">
<p>The module to be searched.</p>
</td></tr>
<tr><td class="val" id="name">name</td><td class="desc">
<p>The name of the interface in the module.</p>
</td></tr>
</table>

<div class="section">
<h3 id="FT_Module_Class">FT_Module_Class</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  <span class="keyword">typedef</span> <span class="keyword">struct</span>  FT_Module_Class_
  {
    <a href="ft2-basic_types.html#FT_ULong">FT_ULong</a>               module_flags;
    <a href="ft2-basic_types.html#FT_Long">FT_Long</a>                module_size;
    <span class="keyword">const</span> <a href="ft2-basic_types.html#FT_String">FT_String</a>*       module_name;
    <a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a>               module_version;
    <a href="ft2-basic_types.html#FT_Fixed">FT_Fixed</a>               module_requires;

<span class="keyword">const</span> <span class="keyword">void</span>*            module_interface;

<a href="ft2-module_management.html#FT_Module_Constructor">FT_Module_Constructor</a>  module_init;
    <a href="ft2-module_management.html#FT_Module_Destructor">FT_Module_Destructor</a>   module_done;
    <a href="ft2-module_management.html#FT_Module_Requester">FT_Module_Requester</a>    get_interface;

} <b>FT_Module_Class</b>;
</pre>

<p>The module class descriptor.</p>

<h4>fields</h4>
<table class="fields">
<tr><td class="val" id="module_flags">module_flags</td><td class="desc">
<p>Bit flags describing the module.</p>
</td></tr>
<tr><td class="val" id="module_size">module_size</td><td class="desc">
<p>The size of one module object/instance in bytes.</p>
</td></tr>
<tr><td class="val" id="module_name">module_name</td><td class="desc">
<p>The name of the module.</p>
</td></tr>
<tr><td class="val" id="module_version">module_version</td><td class="desc">
<p>The version, as a 16.16 fixed number (major.minor).</p>
</td></tr>
<tr><td class="val" id="module_requires">module_requires</td><td class="desc">
<p>The version of FreeType this module requires, as a 16.16 fixed number (major.minor). Starts at version 2.0, i.e., 0x20000.</p>
</td></tr>
<tr><td class="val" id="module_init">module_init</td><td class="desc">
<p>The initializing function.</p>
</td></tr>
<tr><td class="val" id="module_done">module_done</td><td class="desc">
<p>The finalizing function.</p>
</td></tr>
<tr><td class="val" id="get_interface">get_interface</td><td class="desc">
<p>The interface requesting function.</p>
</td></tr>
</table>

<div class="section">
<h3 id="FT_Add_Module">FT_Add_Module</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_Add_Module</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>              library,
                 <span class="keyword">const</span> <a href="ft2-module_management.html#FT_Module_Class">FT_Module_Class</a>*  clazz );
</pre>

<p>Add a new module to a given library instance.</p>

<h4>inout</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the library object.</p>
</td></tr>
</table>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="clazz">clazz</td><td class="desc">
<p>A pointer to class descriptor for the module.</p>
</td></tr>
</table>

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

<h4>note</h4>
<p>An error will be returned if a module already exists by that name, or if the module requires a version of FreeType that is too great.</p>

<div class="section">
<h3 id="FT_Get_Module">FT_Get_Module</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-module_management.html#FT_Module">FT_Module</a> )
  <b>FT_Get_Module</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>   library,
                 <span class="keyword">const</span> <span class="keyword">char</span>*  module_name );
</pre>

<p>Find a module by its name.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the library object.</p>
</td></tr>
<tr><td class="val" id="module_name">module_name</td><td class="desc">
<p>The module's name (as an ASCII string).</p>
</td></tr>
</table>

<h4>return</h4>
<p>A module handle. 0&nbsp;if none was found.</p>

<h4>note</h4>
<p>FreeType's internal modules aren't documented very well, and you should look up the source code for details.</p>

<div class="section">
<h3 id="FT_Remove_Module">FT_Remove_Module</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_Remove_Module</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>  library,
                    <a href="ft2-module_management.html#FT_Module">FT_Module</a>   module );
</pre>

<p>Remove a given module from a library instance.</p>

<h4>inout</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to a library object.</p>
</td></tr>
</table>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="module">module</td><td class="desc">
<p>A handle to a module object.</p>
</td></tr>
</table>

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

<h4>note</h4>
<p>The module object is destroyed by the function in case of success.</p>

<div class="section">
<h3 id="FT_Add_Default_Modules">FT_Add_Default_Modules</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <span class="keyword">void</span> )
  <b>FT_Add_Default_Modules</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>  library );
</pre>

<p>Add the set of default drivers to a given library object. This is only useful when you create a library object with <a href="ft2-module_management.html#FT_New_Library">FT_New_Library</a> (usually to plug a custom memory manager).</p>

<h4>inout</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to a new library object.</p>
</td></tr>
</table>

<div class="section">
<h3 id="FT_Property_Set">FT_Property_Set</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_Property_Set</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>        library,
                   <span class="keyword">const</span> <a href="ft2-basic_types.html#FT_String">FT_String</a>*  module_name,
                   <span class="keyword">const</span> <a href="ft2-basic_types.html#FT_String">FT_String</a>*  property_name,
                   <span class="keyword">const</span> <span class="keyword">void</span>*       value );
</pre>

<p>Set a property for a given module.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the library the module is part of.</p>
</td></tr>
<tr><td class="val" id="module_name">module_name</td><td class="desc">
<p>The module name.</p>
</td></tr>
<tr><td class="val" id="property_name">property_name</td><td class="desc">
<p>The property name. Properties are described in section &lsquo;<a href="ft2-properties.html#properties">Driver properties</a>&rsquo;.</p>
<p>Note that only a few modules have properties.</p>
</td></tr>
<tr><td class="val" id="value">value</td><td class="desc">
<p>A generic pointer to a variable or structure that gives the new value of the property. The exact definition of &lsquo;value&rsquo; is dependent on the property; see section &lsquo;<a href="ft2-properties.html#properties">Driver properties</a>&rsquo;.</p>
</td></tr>
</table>

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

<h4>note</h4>
<p>If &lsquo;module_name&rsquo; isn't a valid module name, or &lsquo;property_name&rsquo; doesn't specify a valid property, or if &lsquo;value&rsquo; doesn't represent a valid value for the given property, an error is returned.</p>
<p>The following example sets property &lsquo;bar&rsquo; (a simple integer) in module &lsquo;foo&rsquo; to value&nbsp;1.</p>
<pre class="colored">
  FT_UInt  bar;

bar = 1;
  FT_Property_Set( library, "foo", "bar", &amp;bar );
</pre>
<p>Note that the FreeType Cache sub-system doesn't recognize module property changes. To avoid glyph lookup confusion within the cache you should call <a href="ft2-cache_subsystem.html#FTC_Manager_Reset">FTC_Manager_Reset</a> to completely flush the cache if a module property gets changed after <a href="ft2-cache_subsystem.html#FTC_Manager_New">FTC_Manager_New</a> has been called.</p>
<p>It is not possible to set properties of the FreeType Cache sub-system itself with FT_Property_Set; use ?FTC_Property_Set? instead.</p>

<h4>since</h4>
<p>2.4.11</p>

<div class="section">
<h3 id="FT_Property_Get">FT_Property_Get</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_Property_Get</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>        library,
                   <span class="keyword">const</span> <a href="ft2-basic_types.html#FT_String">FT_String</a>*  module_name,
                   <span class="keyword">const</span> <a href="ft2-basic_types.html#FT_String">FT_String</a>*  property_name,
                   <span class="keyword">void</span>*             value );
</pre>

<p>Get a module's property value.</p>

<h4>inout</h4>
<table class="fields">
<tr><td class="val" id="value">value</td><td class="desc">
<p>A generic pointer to a variable or structure that gives the value of the property. The exact definition of &lsquo;value&rsquo; is dependent on the property; see section &lsquo;<a href="ft2-properties.html#properties">Driver properties</a>&rsquo;.</p>
</td></tr>
</table>

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

<h4>note</h4>
<p>If &lsquo;module_name&rsquo; isn't a valid module name, or &lsquo;property_name&rsquo; doesn't specify a valid property, or if &lsquo;value&rsquo; doesn't represent a valid value for the given property, an error is returned.</p>
<p>The following example gets property &lsquo;baz&rsquo; (a range) in module &lsquo;foo&rsquo;.</p>
<pre class="colored">
  typedef  range_
  {
    FT_Int32  min;
    FT_Int32  max;

} range;

range  baz;

FT_Property_Get( library, "foo", "baz", &amp;baz );
</pre>
<p>It is not possible to retrieve properties of the FreeType Cache sub-system with FT_Property_Get; use ?FTC_Property_Get? instead.</p>

<h4>since</h4>
<p>2.4.11</p>

<div class="section">
<h3 id="FT_Set_Default_Properties">FT_Set_Default_Properties</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <span class="keyword">void</span> )
  <b>FT_Set_Default_Properties</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>  library );
</pre>

<p>If compilation option FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES is set, this function reads the &lsquo;FREETYPE_PROPERTIES&rsquo; environment variable to control driver properties. See section &lsquo;<a href="ft2-properties.html#properties">Driver properties</a>&rsquo; for more.</p>
<p>If the compilation option is not set, this function does nothing.</p>
<p>&lsquo;FREETYPE_PROPERTIES&rsquo; has the following syntax form (broken here into multiple lines for better readability).</p>
<pre class="colored">
  &lt;optional whitespace&gt;
  &lt;module-name1&gt; ':'
  &lt;property-name1&gt; '=' &lt;property-value1&gt;
  &lt;whitespace&gt;
  &lt;module-name2&gt; ':'
  &lt;property-name2&gt; '=' &lt;property-value2&gt;
  ...
</pre>
<p>Example:</p>
<pre class="colored">
  FREETYPE_PROPERTIES=truetype:interpreter-version=35 \
                      cff:no-stem-darkening=1 \
                      autofitter:warping=1
</pre>

<h4>inout</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to a new library object.</p>
</td></tr>
</table>

<h4>since</h4>
<p>2.8</p>

<div class="section">
<h3 id="FT_New_Library">FT_New_Library</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_New_Library</b>( <a href="ft2-system_interface.html#FT_Memory">FT_Memory</a>    memory,
                  <a href="ft2-base_interface.html#FT_Library">FT_Library</a>  *alibrary );
</pre>

<p>This function is used to create a new FreeType library instance from a given memory object. It is thus possible to use libraries with distinct memory allocators within the same program. Note, however, that the used <a href="ft2-system_interface.html#FT_Memory">FT_Memory</a> structure is expected to remain valid for the life of the <a href="ft2-base_interface.html#FT_Library">FT_Library</a> object.</p>
<p>Normally, you would call this function (followed by a call to <a href="ft2-module_management.html#FT_Add_Default_Modules">FT_Add_Default_Modules</a> or a series of calls to <a href="ft2-module_management.html#FT_Add_Module">FT_Add_Module</a>, and a call to <a href="ft2-module_management.html#FT_Set_Default_Properties">FT_Set_Default_Properties</a>) instead of <a href="ft2-base_interface.html#FT_Init_FreeType">FT_Init_FreeType</a> to initialize the FreeType library.</p>
<p>Don't use <a href="ft2-base_interface.html#FT_Done_FreeType">FT_Done_FreeType</a> but <a href="ft2-module_management.html#FT_Done_Library">FT_Done_Library</a> to destroy a library instance.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="memory">memory</td><td class="desc">
<p>A handle to the original memory object.</p>
</td></tr>
</table>

<h4>output</h4>
<table class="fields">
<tr><td class="val" id="alibrary">alibrary</td><td class="desc">
<p>A pointer to handle of a new library object.</p>
</td></tr>
</table>

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

<h4>note</h4>
<p>See the discussion of reference counters in the description of <a href="ft2-module_management.html#FT_Reference_Library">FT_Reference_Library</a>.</p>

<div class="section">
<h3 id="FT_Done_Library">FT_Done_Library</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_Done_Library</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>  library );
</pre>

<p>Discard a given library object. This closes all drivers and discards all resource objects.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the target library.</p>
</td></tr>
</table>

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

<h4>note</h4>
<p>See the discussion of reference counters in the description of <a href="ft2-module_management.html#FT_Reference_Library">FT_Reference_Library</a>.</p>

<div class="section">
<h3 id="FT_Reference_Library">FT_Reference_Library</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_Reference_Library</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>  library );
</pre>

<p>A counter gets initialized to&nbsp;1 at the time an <a href="ft2-base_interface.html#FT_Library">FT_Library</a> structure is created. This function increments the counter. <a href="ft2-module_management.html#FT_Done_Library">FT_Done_Library</a> then only destroys a library if the counter is&nbsp;1, otherwise it simply decrements the counter.</p>
<p>This function helps in managing life-cycles of structures that reference <a href="ft2-base_interface.html#FT_Library">FT_Library</a> objects.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to a target library object.</p>
</td></tr>
</table>

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

<h4>since</h4>
<p>2.4.2</p>

<div class="section">
<h3 id="FT_Renderer">FT_Renderer</h3>
<p>Defined in FT_FREETYPE_H (freetype/freetype.h).</p>
<pre>
  <span class="keyword">typedef</span> <span class="keyword">struct</span> FT_RendererRec_*  <b>FT_Renderer</b>;
</pre>

<p>A handle to a given FreeType renderer. A renderer is a module in charge of converting a glyph's outline image to a bitmap. It supports a single glyph image format, and one or more target surface depths.</p>

<div class="section">
<h3 id="FT_Renderer_Class">FT_Renderer_Class</h3>
<p>Defined in FT_RENDER_H (freetype/ftrender.h).</p>
<pre>
  <span class="keyword">typedef</span> <span class="keyword">struct</span>  FT_Renderer_Class_
  {
    <a href="ft2-module_management.html#FT_Module_Class">FT_Module_Class</a>            root;

<a href="ft2-basic_types.html#FT_Glyph_Format">FT_Glyph_Format</a>            glyph_format;

FT_Renderer_RenderFunc     render_glyph;
    FT_Renderer_TransformFunc  transform_glyph;
    FT_Renderer_GetCBoxFunc    get_glyph_cbox;
    FT_Renderer_SetModeFunc    set_mode;

<a href="ft2-raster.html#FT_Raster_Funcs">FT_Raster_Funcs</a>*           raster_class;

} <b>FT_Renderer_Class</b>;
</pre>

<p>The renderer module class descriptor.</p>

<h4>fields</h4>
<table class="fields">
<tr><td class="val" id="root">root</td><td class="desc">
<p>The root <a href="ft2-module_management.html#FT_Module_Class">FT_Module_Class</a> fields.</p>
</td></tr>
<tr><td class="val" id="glyph_format">glyph_format</td><td class="desc">
<p>The glyph image format this renderer handles.</p>
</td></tr>
<tr><td class="val" id="render_glyph">render_glyph</td><td class="desc">
<p>A method used to render the image that is in a given glyph slot into a bitmap.</p>
</td></tr>
<tr><td class="val" id="transform_glyph">transform_glyph</td><td class="desc">
<p>A method used to transform the image that is in a given glyph slot.</p>
</td></tr>
<tr><td class="val" id="get_glyph_cbox">get_glyph_cbox</td><td class="desc">
<p>A method used to access the glyph's cbox.</p>
</td></tr>
<tr><td class="val" id="set_mode">set_mode</td><td class="desc">
<p>A method used to pass additional parameters.</p>
</td></tr>
<tr><td class="val" id="raster_class">raster_class</td><td class="desc">
<p>For <a href="ft2-basic_types.html#FT_Glyph_Format">FT_GLYPH_FORMAT_OUTLINE</a> renderers only. This is a pointer to its raster's class.</p>
</td></tr>
</table>

<div class="section">
<h3 id="FT_Get_Renderer">FT_Get_Renderer</h3>
<p>Defined in FT_RENDER_H (freetype/ftrender.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-module_management.html#FT_Renderer">FT_Renderer</a> )
  <b>FT_Get_Renderer</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>       library,
                   <a href="ft2-basic_types.html#FT_Glyph_Format">FT_Glyph_Format</a>  format );
</pre>

<p>Retrieve the current renderer for a given glyph format.</p>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the library object.</p>
</td></tr>
<tr><td class="val" id="format">format</td><td class="desc">
<p>The glyph format.</p>
</td></tr>
</table>

<h4>return</h4>
<p>A renderer handle. 0&nbsp;if none found.</p>

<h4>note</h4>
<p>An error will be returned if a module already exists by that name, or if the module requires a version of FreeType that is too great.</p>
<p>To add a new renderer, simply use <a href="ft2-module_management.html#FT_Add_Module">FT_Add_Module</a>. To retrieve a renderer by its name, use <a href="ft2-module_management.html#FT_Get_Module">FT_Get_Module</a>.</p>

<div class="section">
<h3 id="FT_Set_Renderer">FT_Set_Renderer</h3>
<p>Defined in FT_RENDER_H (freetype/ftrender.h).</p>
<pre>
  FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
  <b>FT_Set_Renderer</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>     library,
                   <a href="ft2-module_management.html#FT_Renderer">FT_Renderer</a>    renderer,
                   <a href="ft2-basic_types.html#FT_UInt">FT_UInt</a>        num_params,
                   <a href="ft2-base_interface.html#FT_Parameter">FT_Parameter</a>*  parameters );
</pre>

<p>Set the current renderer to use, and set additional mode.</p>

<h4>inout</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the library object.</p>
</td></tr>
</table>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="renderer">renderer</td><td class="desc">
<p>A handle to the renderer object.</p>
</td></tr>
<tr><td class="val" id="num_params">num_params</td><td class="desc">
<p>The number of additional parameters.</p>
</td></tr>
<tr><td class="val" id="parameters">parameters</td><td class="desc">
<p>Additional parameters.</p>
</td></tr>
</table>

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

<h4>note</h4>
<p>In case of success, the renderer will be used to convert glyph images in the renderer's known format into bitmaps.</p>
<p>This doesn't change the current renderer for other formats.</p>
<p>Currently, no FreeType renderer module uses &lsquo;parameters&rsquo;; you should thus always pass NULL as the value.</p>

<div class="section">
<h3 id="FT_Set_Debug_Hook">FT_Set_Debug_Hook</h3>
<p>Defined in FT_MODULE_H (freetype/ftmodapi.h).</p>
<pre>
  FT_EXPORT( <span class="keyword">void</span> )
  <b>FT_Set_Debug_Hook</b>( <a href="ft2-base_interface.html#FT_Library">FT_Library</a>         library,
                     <a href="ft2-basic_types.html#FT_UInt">FT_UInt</a>            hook_index,
                     FT_DebugHook_Func  debug_hook );
</pre>

<p>Set a debug hook function for debugging the interpreter of a font format.</p>

<h4>inout</h4>
<table class="fields">
<tr><td class="val" id="library">library</td><td class="desc">
<p>A handle to the library object.</p>
</td></tr>
</table>

<h4>input</h4>
<table class="fields">
<tr><td class="val" id="hook_index">hook_index</td><td class="desc">
<p>The index of the debug hook. You should use the values defined in &lsquo;ftobjs.h&rsquo;, e.g., &lsquo;FT_DEBUG_HOOK_TRUETYPE&rsquo;.</p>
</td></tr>
<tr><td class="val" id="debug_hook">debug_hook</td><td class="desc">
<p>The function used to debug the interpreter.</p>
</td></tr>
</table>

<h4>note</h4>
<p>Currently, four debug hook slots are available, but only two (for the TrueType and the Type&nbsp;1 interpreter) are defined.</p>
<p>Since the internal headers of FreeType are no longer installed, the symbol &lsquo;FT_DEBUG_HOOK_TRUETYPE&rsquo; isn't available publicly. This is a bug and will be fixed in a forthcoming release.</p>

<div class="section">
<h3 id="FT_Driver">FT_Driver</h3>
<p>Defined in FT_FREETYPE_H (freetype/freetype.h).</p>
<pre>
  <span class="keyword">typedef</span> <span class="keyword">struct</span> FT_DriverRec_*  <b>FT_Driver</b>;
</pre>

<p>A handle to a given FreeType font driver object. A font driver is a module capable of creating faces from font files.</p>

</body>
</html>

MR SKB