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Cache Sub-System
<
table align=center
cellspacing=5 cellpadding=0 border=0>
<
tr><
td><
/td><
td><
a href="#FTC_Manager">FTC_Manager<
/a><
/td><
td><
/td><
td><
a href="#FTC_CMapCache_New">FTC_CMapCache_New<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_FaceID">FTC_FaceID<
/a><
/td><
td><
/td><
td><
a href="#FTC_CMapCache_Lookup">FTC_CMapCache_Lookup<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_Face_Requester">FTC_Face_Requester<
/a><
/td><
td><
/td><
td><
a href="#FTC_ImageTypeRec">FTC_ImageTypeRec<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_Manager_New">FTC_Manager_New<
/a><
/td><
td><
/td><
td><
a href="#FTC_ImageCache">FTC_ImageCache<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_Manager_Reset">FTC_Manager_Reset<
/a><
/td><
td><
/td><
td><
a href="#FTC_ImageCache_New">FTC_ImageCache_New<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_Manager_Done">FTC_Manager_Done<
/a><
/td><
td><
/td><
td><
a href="#FTC_ImageCache_Lookup">FTC_ImageCache_Lookup<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_Manager_LookupFace">FTC_Manager_LookupFace<
/a><
/td><
td><
/td><
td><
a href="#FTC_ImageCache_LookupScaler">FTC_ImageCache_LookupScaler<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_Manager_LookupSize">FTC_Manager_LookupSize<
/a><
/td><
td><
/td><
td><
a href="#FTC_SBitCache">FTC_SBitCache<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_Node_Unref">FTC_Node_Unref<
/a><
/td><
td><
/td><
td><
a href="#FTC_SBitCache_New">FTC_SBitCache_New<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_Manager_RemoveFaceID">FTC_Manager_RemoveFaceID<
/a><
/td><
td><
/td><
td><
a href="#FTC_SBitCache_Lookup">FTC_SBitCache_Lookup<
/a><
/td><
/tr>
<
tr><
td><
/td><
td><
a href="#FTC_CMapCache">FTC_CMapCache<
/a><
/td><
td><
/td><
td><
a href="#FTC_SBitCache_LookupScaler">FTC_SBitCache_LookupScaler<
/a><
/td><
/tr>
<
p>This section describes the FreeType
2 cache sub-system, which is used to limit the number of concurrently opened <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> and <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> objects, as well as caching information like character maps and glyph images while limiting their maximum memory usage.<
/p>
<
p>Note that all types and functions begin with the ‘FTC_’ prefix.<
/p>
<
p>The cache is highly portable and thus doesn
't know anything about the fonts installed on your system, or how to access them. This implies the following scheme:</p>
<p>First, available or installed font faces are uniquely identified by <a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID</a> values, provided to the cache by the client. Note that the cache only stores and compares these values, and doesn't try to interpret them in any way.<
/p>
<
p>Second, the cache calls, only when needed, a client-provided function to convert an <
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a> into a new <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a>
object. The latter is then completely managed by the cache, including its termination through <
a href="ft2-base_interface.html#FT_Done_Face">FT_Done_Face<
/a>. To monitor termination of
face objects, the finalizer callback in the ‘generic’ field of the <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a>
object can be used, which might also be used to store the <
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a> of the
face.<
/p>
<
p>Clients are free to map
face IDs to anything else. The most simple usage is to associate them to a
(pathname,face_index
) pair that is used to call <
a href="ft2-base_interface.html#FT_New_Face">FT_New_Face<
/a>. However, more complex schemes are also possible.<
/p>
<
p>Note that
for the cache to work correctly, the
face ID values must be <
b>persistent<
/b>, which means that the contents they point to should not change at runtime, or that their
value should not become invalid.<
/p>
<
p>If this is unavoidable
(e.g., when a font is uninstalled at runtime
), you should call <
a href="ft2-cache_subsystem.html#FTC_Manager_RemoveFaceID">FTC_Manager_RemoveFaceID<
/a> as soon as possible, to let the cache get rid of any references to the old <
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a> it may keep internally. Failure to do so will lead to incorrect behaviour or even crashes.<
/p>
<
p>To use the cache,
start with calling <
a href="ft2-cache_subsystem.html#FTC_Manager_New">FTC_Manager_New<
/a> to create a new <
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a>
object, which models a single cache instance. You can then look up <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> and <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> objects with <
a href="ft2-cache_subsystem.html#FTC_Manager_LookupFace">FTC_Manager_LookupFace<
/a> and <
a href="ft2-cache_subsystem.html#FTC_Manager_LookupSize">FTC_Manager_LookupSize<
/a>, respectively.<
/p>
<
p>If you want to use the charmap caching, call <
a href="ft2-cache_subsystem.html#FTC_CMapCache_New">FTC_CMapCache_New<
/a>, then later use <
a href="ft2-cache_subsystem.html#FTC_CMapCache_Lookup">FTC_CMapCache_Lookup<
/a> to perform the equivalent of <
a href="ft2-base_interface.html#FT_Get_Char_Index">FT_Get_Char_Index<
/a>, only much faster.<
/p>
<
p>If you want to use the <
a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph<
/a> caching, call <
a href="ft2-cache_subsystem.html#FTC_ImageCache">FTC_ImageCache<
/a>, then later use <
a href="ft2-cache_subsystem.html#FTC_ImageCache_Lookup">FTC_ImageCache_Lookup<
/a> to retrieve the corresponding <
a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph<
/a> objects from the cache.<
/p>
<
p>If you need lots of small bitmaps, it is much more memory efficient to call <
a href="ft2-cache_subsystem.html#FTC_SBitCache_New">FTC_SBitCache_New<
/a> followed by <
a href="ft2-cache_subsystem.html#FTC_SBitCache_Lookup">FTC_SBitCache_Lookup<
/a>. This returns <
a href="ft2-cache_subsystem.html#FTC_SBitRec">FTC_SBitRec<
/a> structures, which are used to store small bitmaps directly.
(A small bitmap is one whose metrics and dimensions all fit into
8-bit integers
).<
/p>
<
p>We hope to also provide a kerning cache in the near future.<
/p>
<
h4><
a name="FTC_Manager">FTC_Manager<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_ManagerRec_* <
b>FTC_Manager<
/b>;
<
p>This
object corresponds to one instance of the cache-subsystem. It is used to cache one or more <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> objects, along with corresponding <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> objects.<
/p>
<
p>The manager intentionally limits the total number of opened <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> and <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> objects to control memory usage. See the ‘max_faces’ and ‘max_sizes’ parameters of <
a href="ft2-cache_subsystem.html#FTC_Manager_New">FTC_Manager_New<
/a>.<
/p>
<
p>The manager is also used to cache ‘nodes’ of various types while limiting their total memory usage.<
/p>
<
p>All limitations are enforced by keeping lists of managed objects in most-recently-used order, and flushing old nodes to make room
for new ones.<
/p>
<
h4><
a name="FTC_FaceID">FTC_FaceID<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
a href="ft2-basic_types.html#FT_Pointer">FT_Pointer<
/a> <
b>FTC_FaceID<
/b>;
<
p>An opaque pointer
type that is used to identity
face objects. The contents of such objects is application-dependent.<
/p>
<
p>These pointers are typically used to point to a user-defined structure containing a font file path, and
face index.<
/p>
<
p>Never use NULL as a valid <
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a>.<
/p>
<
p>
Face IDs are passed by the client to the cache manager, which calls, when needed, the <
a href="ft2-cache_subsystem.html#FTC_Face_Requester">FTC_Face_Requester<
/a> to translate them into new <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> objects.<
/p>
<
p>If the
content of a given
face ID changes at runtime, or if the
value becomes invalid
(e.g., when uninstalling a font
), you should immediately call <
a href="ft2-cache_subsystem.html#FTC_Manager_RemoveFaceID">FTC_Manager_RemoveFaceID<
/a> before any other cache function.<
/p>
<
p>Failure to do so will result in incorrect behaviour or even memory leaks and crashes.<
/p>
<
h4><
a name="FTC_Face_Requester">FTC_Face_Requester<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
a href="ft2-basic_types.html#FT_Error">FT_Error<
/a>
(*<
b>FTC_Face_Requester<
/b>
)( <
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a> face_id,
<
a href="ft2-base_interface.html#FT_Library">FT_Library<
/a> library,
<
a href="ft2-basic_types.html#FT_Pointer">FT_Pointer<
/a> request_data,
<
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a>* aface
);
<
p>A callback function provided by client applications. It is used by the cache manager to translate a given <
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a> into a new valid <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a>
object, on demand.<
/p>
<
table cellpadding=3 border=0>
<
p>The
face ID to resolve.<
/p>
<
p>A handle to a FreeType library
object.<
/p>
<
p>Application-provided request
data (see note below
).<
/p>
<
table cellpadding=3 border=0>
<
p>A new <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> handle.<
/p>
<
p>FreeType error
code.
0 means success.<
/p>
<
p>The third parameter ‘req_data’ is the same as the one passed by the client when <
a href="ft2-cache_subsystem.html#FTC_Manager_New">FTC_Manager_New<
/a> is called.<
/p>
<
p>The
face requester should not perform funny things on the returned
face object, like creating a new <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a>
for it, or setting a transformation through <
a href="ft2-base_interface.html#FT_Set_Transform">FT_Set_Transform<
/a>!<
/p>
<
h4><
a name="FTC_Node">FTC_Node<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_NodeRec_* <
b>FTC_Node<
/b>;
<
p>An opaque handle to a cache node
object. Each cache node is reference-counted. A node with a count of
0 might be flushed out of a full cache whenever a lookup request is performed.<
/p>
<
p>If you look up nodes, you have the ability to ‘acquire’ them, i.e., to increment their reference count. This will prevent the node from being flushed out of the cache until you explicitly ‘release’ it
(see <
a href="ft2-cache_subsystem.html#FTC_Node_Unref">FTC_Node_Unref<
/a>
).<
/p>
<
p>See also <
a href="ft2-cache_subsystem.html#FTC_SBitCache_Lookup">FTC_SBitCache_Lookup<
/a> and <
a href="ft2-cache_subsystem.html#FTC_ImageCache_Lookup">FTC_ImageCache_Lookup<
/a>.<
/p>
<
h4><
a name="FTC_Manager_New">FTC_Manager_New<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
a href="ft2-basic_types.html#FT_Error">FT_Error<
/a>
)
<
b>FTC_Manager_New<
/b>
( <
a href="ft2-base_interface.html#FT_Library">FT_Library<
/a> library,
<
a href="ft2-basic_types.html#FT_UInt">FT_UInt<
/a> max_faces,
<
a href="ft2-basic_types.html#FT_UInt">FT_UInt<
/a> max_sizes,
<
a href="ft2-basic_types.html#FT_ULong">FT_ULong<
/a> max_bytes,
<
a href="ft2-cache_subsystem.html#FTC_Face_Requester">FTC_Face_Requester<
/a> requester,
<
a href="ft2-basic_types.html#FT_Pointer">FT_Pointer<
/a> req_data,
<
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a> *amanager
);
<
p>Create a new cache manager.<
/p>
<
table cellpadding=3 border=0>
<
p>The parent FreeType library handle to use.<
/p>
<
p>Maximum number of opened <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> objects managed by this cache instance. Use
0 for defaults.<
/p>
<
p>Maximum number of opened <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> objects managed by this cache instance. Use
0 for defaults.<
/p>
<
p>Maximum number of bytes to use
for cached
data nodes. Use
0 for defaults. Note that this
value does not account
for managed <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> and <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> objects.<
/p>
<
p>An application-provided callback used to translate
face IDs into real <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> objects.<
/p>
<
p>A generic pointer that is passed to the requester each time it is called
(see <
a href="ft2-cache_subsystem.html#FTC_Face_Requester">FTC_Face_Requester<
/a>
).<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to a new manager
object.
0 in case of failure.<
/p>
<
p>FreeType error
code.
0 means success.<
/p>
<
h4><
a name="FTC_Manager_Reset">FTC_Manager_Reset<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
span class="keyword">void<
/span>
)
<
b>FTC_Manager_Reset<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a> manager
);
<
p>Empty a given cache manager. This simply gets rid of all the currently cached <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> and <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> objects within the manager.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the manager.<
/p>
<
h4><
a name="FTC_Manager_Done">FTC_Manager_Done<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
span class="keyword">void<
/span>
)
<
b>FTC_Manager_Done<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a> manager
);
<
p>Destroy a given manager after emptying it.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the
target cache manager
object.<
/p>
<
h4><
a name="FTC_Manager_LookupFace">FTC_Manager_LookupFace<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
a href="ft2-basic_types.html#FT_Error">FT_Error<
/a>
)
<
b>FTC_Manager_LookupFace<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a> manager,
<
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a> face_id,
<
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a> *aface
);
<
p>Retrieve the <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a>
object that corresponds to a given
face ID through a cache manager.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the cache manager.<
/p>
<
p>The
ID of the
face object.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the
face object.<
/p>
<
p>FreeType error
code.
0 means success.<
/p>
<
p>The returned <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a>
object is always owned by the manager. You should never try to discard it yourself.<
/p>
<
p>The <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a>
object doesn
't necessarily have a current size object (i.e., face->size can be 0). If you need a specific ‘font size’, use <a href="ft2-cache_subsystem.html#FTC_Manager_LookupSize">FTC_Manager_LookupSize</a> instead.</p>
<p>Never change the face's transformation matrix
(i.e., never call the <
a href="ft2-base_interface.html#FT_Set_Transform">FT_Set_Transform<
/a> function
) on a returned
face! If you need to transform glyphs, do it yourself after glyph loading.<
/p>
<
p>When you perform a lookup, out-of-memory errors are detected <
i>within<
/i> the lookup and force incremental flushes of the cache until enough memory is released
for the lookup to succeed.<
/p>
<
p>If a lookup fails with ‘FT_Err_Out_Of_Memory’ the cache has already been completely flushed, and still no memory was available
for the operation.<
/p>
<
h4><
a name="FTC_ScalerRec">FTC_ScalerRec<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_ScalerRec_
{
<
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a> face_id;
<
a href="ft2-basic_types.html#FT_UInt">FT_UInt<
/a>
width;
<
a href="ft2-basic_types.html#FT_UInt">FT_UInt<
/a>
height;
<
a href="ft2-basic_types.html#FT_Int">FT_Int<
/a> pixel;
<
a href="ft2-basic_types.html#FT_UInt">FT_UInt<
/a> x_res;
<
a href="ft2-basic_types.html#FT_UInt">FT_UInt<
/a> y_res;
<
p>A structure used to describe a given character
size in either pixels or points to the cache manager. See <
a href="ft2-cache_subsystem.html#FTC_Manager_LookupSize">FTC_Manager_LookupSize<
/a>.<
/p>
<
table cellpadding=3 border=0>
<
p>The source
face ID.<
/p>
<
p>The character
width.<
/p>
<
p>The character
height.<
/p>
<
p>A Boolean. If
1, the ‘width’ and ‘height’ fields are interpreted as integer pixel character sizes. Otherwise, they are expressed as
1/64th of points.<
/p>
<
p>Only used when ‘pixel’ is value
0 to indicate the horizontal resolution in dpi.<
/p>
<
p>Only used when ‘pixel’ is value
0 to indicate the vertical resolution in dpi.<
/p>
<
p>This
type is mainly used to retrieve <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> objects through the cache manager.<
/p>
<
h4><
a name="FTC_Scaler">FTC_Scaler<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_ScalerRec_* <
b>FTC_Scaler<
/b>;
<
p>A handle to an <
a href="ft2-cache_subsystem.html#FTC_ScalerRec">FTC_ScalerRec<
/a> structure.<
/p>
<
h4><
a name="FTC_Manager_LookupSize">FTC_Manager_LookupSize<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
a href="ft2-basic_types.html#FT_Error">FT_Error<
/a>
)
<
b>FTC_Manager_LookupSize<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a> manager,
<
a href="ft2-cache_subsystem.html#FTC_Scaler">FTC_Scaler<
/a> scaler,
<
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a> *asize
);
<
p>Retrieve the <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a>
object that corresponds to a given <
a href="ft2-cache_subsystem.html#FTC_ScalerRec">FTC_ScalerRec<
/a> pointer through a cache manager.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the cache manager.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the
size object.<
/p>
<
p>FreeType error
code.
0 means success.<
/p>
<
p>The returned <
a href="ft2-base_interface.html#FT_Size">FT_Size<
/a>
object is always owned by the manager. You should never try to discard it by yourself.<
/p>
<
p>You can access the parent <
a href="ft2-base_interface.html#FT_Face">FT_Face<
/a>
object simply as ‘size->face’ if you need it. Note that this
object is also owned by the manager.<
/p>
<
p>When you perform a lookup, out-of-memory errors are detected <
i>within<
/i> the lookup and force incremental flushes of the cache until enough memory is released
for the lookup to succeed.<
/p>
<
p>If a lookup fails with ‘FT_Err_Out_Of_Memory’ the cache has already been completely flushed, and still no memory is available
for the operation.<
/p>
<
h4><
a name="FTC_Node_Unref">FTC_Node_Unref<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
span class="keyword">void<
/span>
)
<
b>FTC_Node_Unref<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_Node">FTC_Node<
/a> node,
<
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a> manager
);
<
p>Decrement a cache node
's internal reference count. When the count reaches 0, it is not destroyed but becomes eligible for subsequent cache flushes.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>node</b></td><td>
<p>The cache node handle.</p>
</td></tr>
<tr valign=top><td><b>manager</b></td><td>
<p>The cache manager handle.</p>
</td></tr>
</table>
</td></tr></table>
</td></tr></table>
<hr width="75%">
<table align=center width="75%"><tr><td><font size=-2>[<a href="ft2-index.html">Index</a>]</font></td>
<td width="100%"></td>
<td><font size=-2>[<a href="ft2-toc.html">TOC</a>]</font></td></tr></table>
<table align=center width="75%"><tr><td>
<h4><a name="FTC_Manager_RemoveFaceID">FTC_Manager_RemoveFaceID</a></h4>
<table align=center width="87%"><tr><td>
Defined in FT_CACHE_H (freetype/ftcache.h).
</td></tr></table><br>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>
FT_EXPORT( <span class="keyword">void</span> )
<b>FTC_Manager_RemoveFaceID</b>( <a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager</a> manager,
<a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID</a> face_id );
</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A special function used to indicate to the cache manager that a given <a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID</a> is no longer valid, either because its content changed, or because it was deallocated or uninstalled.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>manager</b></td><td>
<p>The cache manager handle.</p>
</td></tr>
<tr valign=top><td><b>face_id</b></td><td>
<p>The <a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID</a> to be removed.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>note</b></em></td></tr><tr><td>
<p>This function flushes all nodes from the cache corresponding to this ‘face_id’, with the exception of nodes with a non-null reference count.</p>
<p>Such nodes are however modified internally so as to never appear in later lookups with the same ‘face_id’ value, and to be immediately destroyed when released by all their users.</p>
</td></tr></table>
</td></tr></table>
<hr width="75%">
<table align=center width="75%"><tr><td><font size=-2>[<a href="ft2-index.html">Index</a>]</font></td>
<td width="100%"></td>
<td><font size=-2>[<a href="ft2-toc.html">TOC</a>]</font></td></tr></table>
<table align=center width="75%"><tr><td>
<h4><a name="FTC_CMapCache">FTC_CMapCache</a></h4>
<table align=center width="87%"><tr><td>
Defined in FT_CACHE_H (freetype/ftcache.h).
</td></tr></table><br>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>
<span class="keyword">typedef</span> <span class="keyword">struct</span> FTC_CMapCacheRec_* <b>FTC_CMapCache</b>;
</pre></table><br>
<table align=center width="87%"><tr><td>
<p>An opaque handle used to model a charmap cache. This cache is to hold character codes -> glyph indices mappings.</p>
</td></tr></table><br>
</td></tr></table>
<hr width="75%">
<table align=center width="75%"><tr><td><font size=-2>[<a href="ft2-index.html">Index</a>]</font></td>
<td width="100%"></td>
<td><font size=-2>[<a href="ft2-toc.html">TOC</a>]</font></td></tr></table>
<table align=center width="75%"><tr><td>
<h4><a name="FTC_CMapCache_New">FTC_CMapCache_New</a></h4>
<table align=center width="87%"><tr><td>
Defined in FT_CACHE_H (freetype/ftcache.h).
</td></tr></table><br>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>
FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
<b>FTC_CMapCache_New</b>( <a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager</a> manager,
<a href="ft2-cache_subsystem.html#FTC_CMapCache">FTC_CMapCache</a> *acache );
</pre></table><br>
<table align=center width="87%"><tr><td>
<p>Create a new charmap cache.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>manager</b></td><td>
<p>A handle to the cache manager.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>output</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>acache</b></td><td>
<p>A new cache handle. NULL in case of error.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>return</b></em></td></tr><tr><td>
<p>FreeType error code. 0 means success.</p>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>note</b></em></td></tr><tr><td>
<p>Like all other caches, this one will be destroyed with the cache manager.</p>
</td></tr></table>
</td></tr></table>
<hr width="75%">
<table align=center width="75%"><tr><td><font size=-2>[<a href="ft2-index.html">Index</a>]</font></td>
<td width="100%"></td>
<td><font size=-2>[<a href="ft2-toc.html">TOC</a>]</font></td></tr></table>
<table align=center width="75%"><tr><td>
<h4><a name="FTC_CMapCache_Lookup">FTC_CMapCache_Lookup</a></h4>
<table align=center width="87%"><tr><td>
Defined in FT_CACHE_H (freetype/ftcache.h).
</td></tr></table><br>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>
FT_EXPORT( <a href="ft2-basic_types.html#FT_UInt">FT_UInt</a> )
<b>FTC_CMapCache_Lookup</b>( <a href="ft2-cache_subsystem.html#FTC_CMapCache">FTC_CMapCache</a> cache,
<a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID</a> face_id,
<a href="ft2-basic_types.html#FT_Int">FT_Int</a> cmap_index,
<a href="ft2-basic_types.html#FT_UInt32">FT_UInt32</a> char_code );
</pre></table><br>
<table align=center width="87%"><tr><td>
<p>Translate a character code into a glyph index, using the charmap cache.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>cache</b></td><td>
<p>A charmap cache handle.</p>
</td></tr>
<tr valign=top><td><b>face_id</b></td><td>
<p>The source face ID.</p>
</td></tr>
<tr valign=top><td><b>cmap_index</b></td><td>
<p>The index of the charmap in the source face. Any negative value means to use the cache <a href="ft2-base_interface.html#FT_Face">FT_Face</a>'s default charmap.<
/p>
<
p>The character
code (in the corresponding charmap
).<
/p>
<
p>Glyph index.
0 means ‘no glyph’.<
/p>
<
h4><
a name="FTC_ImageTypeRec">FTC_ImageTypeRec<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_ImageTypeRec_
{
<
a href="ft2-cache_subsystem.html#FTC_FaceID">FTC_FaceID<
/a> face_id;
<
a href="ft2-basic_types.html#FT_Int">FT_Int<
/a>
width;
<
a href="ft2-basic_types.html#FT_Int">FT_Int<
/a>
height;
<
a href="ft2-basic_types.html#FT_Int32">FT_Int32<
/a> flags;
} <
b>FTC_ImageTypeRec<
/b>;
<
p>A structure used to model the
type of images in a glyph cache.<
/p>
<
table cellpadding=3 border=0>
<
p>The
width in pixels.<
/p>
<
p>The
height in pixels.<
/p>
<
p>The load flags, as in <
a href="ft2-base_interface.html#FT_Load_Glyph">FT_Load_Glyph<
/a>.<
/p>
<
h4><
a name="FTC_ImageType">FTC_ImageType<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_ImageTypeRec_* <
b>FTC_ImageType<
/b>;
<
p>A handle to an <
a href="ft2-cache_subsystem.html#FTC_ImageTypeRec">FTC_ImageTypeRec<
/a> structure.<
/p>
<
h4><
a name="FTC_ImageCache">FTC_ImageCache<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_ImageCacheRec_* <
b>FTC_ImageCache<
/b>;
<
p>A handle to a glyph image cache
object. They are designed to hold many distinct glyph images while not exceeding a certain memory threshold.<
/p>
<
h4><
a name="FTC_ImageCache_New">FTC_ImageCache_New<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
a href="ft2-basic_types.html#FT_Error">FT_Error<
/a>
)
<
b>FTC_ImageCache_New<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a> manager,
<
a href="ft2-cache_subsystem.html#FTC_ImageCache">FTC_ImageCache<
/a> *acache
);
<
p>Create a new glyph image cache.<
/p>
<
table cellpadding=3 border=0>
<
p>The parent manager
for the image cache.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the new glyph image cache
object.<
/p>
<
p>FreeType error
code.
0 means success.<
/p>
<
h4><
a name="FTC_ImageCache_Lookup">FTC_ImageCache_Lookup<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
a href="ft2-basic_types.html#FT_Error">FT_Error<
/a>
)
<
b>FTC_ImageCache_Lookup<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_ImageCache">FTC_ImageCache<
/a> cache,
<
a href="ft2-cache_subsystem.html#FTC_ImageType">FTC_ImageType<
/a>
type,
<
a href="ft2-basic_types.html#FT_UInt">FT_UInt<
/a> gindex,
<
a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph<
/a> *aglyph,
<
a href="ft2-cache_subsystem.html#FTC_Node">FTC_Node<
/a> *anode
);
<
p>Retrieve a given glyph image from a glyph image cache.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the source glyph image cache.<
/p>
<
p>A pointer to a glyph image
type descriptor.<
/p>
<
p>The glyph index to retrieve.<
/p>
<
table cellpadding=3 border=0>
<
p>The corresponding <
a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph<
/a>
object.
0 in case of failure.<
/p>
<
p>Used to return the address of of the corresponding cache node after incrementing its reference count
(see note below
).<
/p>
<
p>FreeType error
code.
0 means success.<
/p>
<
p>The returned glyph is owned and managed by the glyph image cache. Never try to transform or discard it manually! You can however create a copy with <
a href="ft2-glyph_management.html#FT_Glyph_Copy">FT_Glyph_Copy<
/a> and modify the new one.<
/p>
<
p>If ‘anode’ is <
i>not<
/i> NULL, it receives the address of the cache node containing the glyph image, after increasing its reference count. This ensures that the node
(as well as the <
a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph<
/a>
) will always be kept in the cache until you call <
a href="ft2-cache_subsystem.html#FTC_Node_Unref">FTC_Node_Unref<
/a> to ‘release’ it.<
/p>
<
p>If ‘anode’ is NULL, the cache node is left unchanged, which means that the <
a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph<
/a> could be flushed out of the cache on the next call to one of the caching sub-system APIs. Don
't assume that it is persistent!</p>
</td></tr></table>
</td></tr></table>
<hr width="75%">
<table align=center width="75%"><tr><td><font size=-2>[<a href="ft2-index.html">Index</a>]</font></td>
<td width="100%"></td>
<td><font size=-2>[<a href="ft2-toc.html">TOC</a>]</font></td></tr></table>
<table align=center width="75%"><tr><td>
<h4><a name="FTC_ImageCache_LookupScaler">FTC_ImageCache_LookupScaler</a></h4>
<table align=center width="87%"><tr><td>
Defined in FT_CACHE_H (freetype/ftcache.h).
</td></tr></table><br>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>
FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
<b>FTC_ImageCache_LookupScaler</b>( <a href="ft2-cache_subsystem.html#FTC_ImageCache">FTC_ImageCache</a> cache,
<a href="ft2-cache_subsystem.html#FTC_Scaler">FTC_Scaler</a> scaler,
<a href="ft2-basic_types.html#FT_ULong">FT_ULong</a> load_flags,
<a href="ft2-basic_types.html#FT_UInt">FT_UInt</a> gindex,
<a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph</a> *aglyph,
<a href="ft2-cache_subsystem.html#FTC_Node">FTC_Node</a> *anode );
</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A variant of <a href="ft2-cache_subsystem.html#FTC_ImageCache_Lookup">FTC_ImageCache_Lookup</a> that uses an <a href="ft2-cache_subsystem.html#FTC_ScalerRec">FTC_ScalerRec</a> to specify the face ID and its size.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>cache</b></td><td>
<p>A handle to the source glyph image cache.</p>
</td></tr>
<tr valign=top><td><b>scaler</b></td><td>
<p>A pointer to a scaler descriptor.</p>
</td></tr>
<tr valign=top><td><b>load_flags</b></td><td>
<p>The corresponding load flags.</p>
</td></tr>
<tr valign=top><td><b>gindex</b></td><td>
<p>The glyph index to retrieve.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>output</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>aglyph</b></td><td>
<p>The corresponding <a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph</a> object. 0 in case of failure.</p>
</td></tr>
<tr valign=top><td><b>anode</b></td><td>
<p>Used to return the address of of the corresponding cache node after incrementing its reference count (see note below).</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>return</b></em></td></tr><tr><td>
<p>FreeType error code. 0 means success.</p>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>note</b></em></td></tr><tr><td>
<p>The returned glyph is owned and managed by the glyph image cache. Never try to transform or discard it manually! You can however create a copy with <a href="ft2-glyph_management.html#FT_Glyph_Copy">FT_Glyph_Copy</a> and modify the new one.</p>
<p>If ‘anode’ is <i>not</i> NULL, it receives the address of the cache node containing the glyph image, after increasing its reference count. This ensures that the node (as well as the <a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph</a>) will always be kept in the cache until you call <a href="ft2-cache_subsystem.html#FTC_Node_Unref">FTC_Node_Unref</a> to ‘release’ it.</p>
<p>If ‘anode’ is NULL, the cache node is left unchanged, which means that the <a href="ft2-glyph_management.html#FT_Glyph">FT_Glyph</a> could be flushed out of the cache on the next call to one of the caching sub-system APIs. Don't assume that it is persistent!<
/p>
<
p>Calls to <
a href="ft2-base_interface.html#FT_Set_Char_Size">FT_Set_Char_Size<
/a> and friends have no effect on cached glyphs; you should always use the FreeType cache API instead.<
/p>
<
h4><
a name="FTC_SBit">FTC_SBit<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_SBitRec_* <
b>FTC_SBit<
/b>;
<
p>A handle to a small bitmap descriptor. See the <
a href="ft2-cache_subsystem.html#FTC_SBitRec">FTC_SBitRec<
/a> structure
for details.<
/p>
<
h4><
a name="FTC_SBitRec">FTC_SBitRec<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_SBitRec_
{
<
a href="ft2-basic_types.html#FT_Byte">FT_Byte<
/a>
width;
<
a href="ft2-basic_types.html#FT_Byte">FT_Byte<
/a>
height;
<
a href="ft2-basic_types.html#FT_Char">FT_Char<
/a> left;
<
a href="ft2-basic_types.html#FT_Char">FT_Char<
/a> top;
<
a href="ft2-basic_types.html#FT_Byte">FT_Byte<
/a> format;
<
a href="ft2-basic_types.html#FT_Byte">FT_Byte<
/a> max_grays;
<
a href="ft2-basic_types.html#FT_Short">FT_Short<
/a> pitch;
<
a href="ft2-basic_types.html#FT_Char">FT_Char<
/a> xadvance;
<
a href="ft2-basic_types.html#FT_Char">FT_Char<
/a> yadvance;
<
a href="ft2-basic_types.html#FT_Byte">FT_Byte<
/a>* buffer;
<
p>A very
compact structure used to describe a small glyph bitmap.<
/p>
<
table cellpadding=3 border=0>
<
p>The bitmap
width in pixels.<
/p>
<
p>The bitmap
height in pixels.<
/p>
<
p>The horizontal distance from the pen position to the left bitmap
border (a.k.a. ‘left side bearing’, or ‘lsb’
).<
/p>
<
p>The vertical distance from the pen position
(on the baseline
) to the upper bitmap
border (a.k.a. ‘top side bearing’
). The distance is positive
for upwards y coordinates.<
/p>
<
p>The format of the glyph bitmap
(monochrome or gray
).<
/p>
<
p>Maximum gray level
value (in the range
1 to
255).<
/p>
<
p>The number of bytes per bitmap line. May be positive or negative.<
/p>
<
p>The horizontal advance
width in pixels.<
/p>
<
p>The vertical advance
height in pixels.<
/p>
<
p>A pointer to the bitmap pixels.<
/p>
<
h4><
a name="FTC_SBitCache">FTC_SBitCache<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
<
span class="keyword">typedef<
/span> <
span class="keyword">struct<
/span> FTC_SBitCacheRec_* <
b>FTC_SBitCache<
/b>;
<
p>A handle to a small bitmap cache. These are special cache objects used to store small glyph bitmaps
(and anti-aliased pixmaps
) in a much more efficient way than the traditional glyph image cache implemented by <
a href="ft2-cache_subsystem.html#FTC_ImageCache">FTC_ImageCache<
/a>.<
/p>
<
h4><
a name="FTC_SBitCache_New">FTC_SBitCache_New<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
a href="ft2-basic_types.html#FT_Error">FT_Error<
/a>
)
<
b>FTC_SBitCache_New<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_Manager">FTC_Manager<
/a> manager,
<
a href="ft2-cache_subsystem.html#FTC_SBitCache">FTC_SBitCache<
/a> *acache
);
<
p>Create a new cache to store small glyph bitmaps.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the source cache manager.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the new sbit cache. NULL in case of error.<
/p>
<
p>FreeType error
code.
0 means success.<
/p>
<
h4><
a name="FTC_SBitCache_Lookup">FTC_SBitCache_Lookup<
/a><
/h4>
Defined in FT_CACHE_H (freetype/ftcache.h).
<
table align=center
width="87%"><
tr bgcolor="#D6E8FF"><
td><
pre>
FT_EXPORT
( <
a href="ft2-basic_types.html#FT_Error">FT_Error<
/a>
)
<
b>FTC_SBitCache_Lookup<
/b>
( <
a href="ft2-cache_subsystem.html#FTC_SBitCache">FTC_SBitCache<
/a> cache,
<
a href="ft2-cache_subsystem.html#FTC_ImageType">FTC_ImageType<
/a>
type,
<
a href="ft2-basic_types.html#FT_UInt">FT_UInt<
/a> gindex,
<
a href="ft2-cache_subsystem.html#FTC_SBit">FTC_SBit<
/a> *sbit,
<
a href="ft2-cache_subsystem.html#FTC_Node">FTC_Node<
/a> *anode
);
<
p>Look up a given small glyph bitmap in a given sbit cache and ‘lock’ it to prevent its flushing from the cache until needed.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to the source sbit cache.<
/p>
<
p>A pointer to the glyph image
type descriptor.<
/p>
<
table cellpadding=3 border=0>
<
p>A handle to a small bitmap descriptor.<
/p>
<
p>Used to return the address of of the corresponding cache node after incrementing its reference count
(see note below
).<
/p>
<
p>FreeType error
code.
0 means success.<
/p>
<
p>The small bitmap descriptor and its bit buffer are owned by the cache and should never be freed by the application. They might as well disappear from memory on the next cache lookup, so don
't treat them as persistent data.</p>
<p>The descriptor's ‘buffer’ field is set to
0 to indicate a missing glyph bitmap.<
/p>
<
p>If ‘anode’ is <
i>not<
/i> NULL, it receives the address of the cache node containing the bitmap, after increasing its reference count. This ensures that the node
(as well as the image
) will always be kept in the cache until you call <
a href="ft2-cache_subsystem.html#FTC_Node_Unref">FTC_Node_Unref<
/a> to ‘release’ it.<
/p>
<
p>If ‘anode’ is NULL, the cache node is left unchanged, which means that the bitmap could be flushed out of the cache on the next call to one of the caching sub-system APIs. Don
't assume that it is persistent!</p>
</td></tr></table>
</td></tr></table>
<hr width="75%">
<table align=center width="75%"><tr><td><font size=-2>[<a href="ft2-index.html">Index</a>]</font></td>
<td width="100%"></td>
<td><font size=-2>[<a href="ft2-toc.html">TOC</a>]</font></td></tr></table>
<table align=center width="75%"><tr><td>
<h4><a name="FTC_SBitCache_LookupScaler">FTC_SBitCache_LookupScaler</a></h4>
<table align=center width="87%"><tr><td>
Defined in FT_CACHE_H (freetype/ftcache.h).
</td></tr></table><br>
<table align=center width="87%"><tr bgcolor="#D6E8FF"><td><pre>
FT_EXPORT( <a href="ft2-basic_types.html#FT_Error">FT_Error</a> )
<b>FTC_SBitCache_LookupScaler</b>( <a href="ft2-cache_subsystem.html#FTC_SBitCache">FTC_SBitCache</a> cache,
<a href="ft2-cache_subsystem.html#FTC_Scaler">FTC_Scaler</a> scaler,
<a href="ft2-basic_types.html#FT_ULong">FT_ULong</a> load_flags,
<a href="ft2-basic_types.html#FT_UInt">FT_UInt</a> gindex,
<a href="ft2-cache_subsystem.html#FTC_SBit">FTC_SBit</a> *sbit,
<a href="ft2-cache_subsystem.html#FTC_Node">FTC_Node</a> *anode );
</pre></table><br>
<table align=center width="87%"><tr><td>
<p>A variant of <a href="ft2-cache_subsystem.html#FTC_SBitCache_Lookup">FTC_SBitCache_Lookup</a> that uses an <a href="ft2-cache_subsystem.html#FTC_ScalerRec">FTC_ScalerRec</a> to specify the face ID and its size.</p>
</td></tr></table><br>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>input</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>cache</b></td><td>
<p>A handle to the source sbit cache.</p>
</td></tr>
<tr valign=top><td><b>scaler</b></td><td>
<p>A pointer to the scaler descriptor.</p>
</td></tr>
<tr valign=top><td><b>load_flags</b></td><td>
<p>The corresponding load flags.</p>
</td></tr>
<tr valign=top><td><b>gindex</b></td><td>
<p>The glyph index.</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>output</b></em></td></tr><tr><td>
<p></p>
<table cellpadding=3 border=0>
<tr valign=top><td><b>sbit</b></td><td>
<p>A handle to a small bitmap descriptor.</p>
</td></tr>
<tr valign=top><td><b>anode</b></td><td>
<p>Used to return the address of of the corresponding cache node after incrementing its reference count (see note below).</p>
</td></tr>
</table>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>return</b></em></td></tr><tr><td>
<p>FreeType error code. 0 means success.</p>
</td></tr></table>
<table align=center width="87%" cellpadding=5><tr bgcolor="#EEEEFF"><td><em><b>note</b></em></td></tr><tr><td>
<p>The small bitmap descriptor and its bit buffer are owned by the cache and should never be freed by the application. They might as well disappear from memory on the next cache lookup, so don't treat them as persistent
data.<
/p>
<
p>The descriptor
's ‘buffer’ field is set to 0 to indicate a missing glyph bitmap.</p>
<p>If ‘anode’ is <i>not</i> NULL, it receives the address of the cache node containing the bitmap, after increasing its reference count. This ensures that the node (as well as the image) will always be kept in the cache until you call <a href="ft2-cache_subsystem.html#FTC_Node_Unref">FTC_Node_Unref</a> to ‘release’ it.</p>
<p>If ‘anode’ is NULL, the cache node is left unchanged, which means that the bitmap could be flushed out of the cache on the next call to one of the caching sub-system APIs. Don't assume that it is persistent!<
/p>