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+/***************************************************************************/
+/* */
+/* ftcache.h */
+/* */
+/* FreeType Cache subsystem (specification). */
+/* */
+/* Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007 by */
+/* David Turner, Robert Wilhelm, and Werner Lemberg. */
+/* */
+/* This file is part of the FreeType project, and may only be used, */
+/* modified, and distributed under the terms of the FreeType project */
+/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
+/* this file you indicate that you have read the license and */
+/* understand and accept it fully. */
+/* */
+/***************************************************************************/
+
+
+#ifndef __FTCACHE_H__
+#define __FTCACHE_H__
+
+
+#include <ft2build.h>
+#include FT_GLYPH_H
+
+
+FT_BEGIN_HEADER
+
+
+ /*************************************************************************
+ *
+ * <Section>
+ * cache_subsystem
+ *
+ * <Title>
+ * Cache Sub-System
+ *
+ * <Abstract>
+ * How to cache face, size, and glyph data with FreeType 2.
+ *
+ * <Description>
+ * This section describes the FreeType 2 cache sub-system, which is used
+ * to limit the number of concurrently opened @FT_Face and @FT_Size
+ * objects, as well as caching information like character maps and glyph
+ * images while limiting their maximum memory usage.
+ *
+ * Note that all types and functions begin with the `FTC_' prefix.
+ *
+ * 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:
+ *
+ * First, available or installed font faces are uniquely identified by
+ * @FTC_FaceID 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.
+ *
+ * Second, the cache calls, only when needed, a client-provided function
+ * to convert a @FTC_FaceID into a new @FT_Face object. The latter is
+ * then completely managed by the cache, including its termination
+ * through @FT_Done_Face.
+ *
+ * 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 @FT_New_Face. However, more complex schemes are also
+ * possible.
+ *
+ * Note that for the cache to work correctly, the face ID values must be
+ * *persistent*, which means that the contents they point to should not
+ * change at runtime, or that their value should not become invalid.
+ *
+ * If this is unavoidable (e.g., when a font is uninstalled at runtime),
+ * you should call @FTC_Manager_RemoveFaceID as soon as possible, to let
+ * the cache get rid of any references to the old @FTC_FaceID it may
+ * keep internally. Failure to do so will lead to incorrect behaviour
+ * or even crashes.
+ *
+ * To use the cache, start with calling @FTC_Manager_New to create a new
+ * @FTC_Manager object, which models a single cache instance. You can
+ * then look up @FT_Face and @FT_Size objects with
+ * @FTC_Manager_LookupFace and @FTC_Manager_LookupSize, respectively.
+ *
+ * If you want to use the charmap caching, call @FTC_CMapCache_New, then
+ * later use @FTC_CMapCache_Lookup to perform the equivalent of
+ * @FT_Get_Char_Index, only much faster.
+ *
+ * If you want to use the @FT_Glyph caching, call @FTC_ImageCache, then
+ * later use @FTC_ImageCache_Lookup to retrieve the corresponding
+ * @FT_Glyph objects from the cache.
+ *
+ * If you need lots of small bitmaps, it is much more memory efficient
+ * to call @FTC_SBitCache_New followed by @FTC_SBitCache_Lookup. This
+ * returns @FTC_SBitRec structures, which are used to store small
+ * bitmaps directly. (A small bitmap is one whose metrics and
+ * dimensions all fit into 8-bit integers).
+ *
+ * We hope to also provide a kerning cache in the near future.
+ *
+ *
+ * <Order>
+ * FTC_Manager
+ * FTC_FaceID
+ * FTC_Face_Requester
+ *
+ * FTC_Manager_New
+ * FTC_Manager_Reset
+ * FTC_Manager_Done
+ * FTC_Manager_LookupFace
+ * FTC_Manager_LookupSize
+ * FTC_Manager_RemoveFaceID
+ *
+ * FTC_Node
+ * FTC_Node_Unref
+ *
+ * FTC_ImageCache
+ * FTC_ImageCache_New
+ * FTC_ImageCache_Lookup
+ *
+ * FTC_SBit
+ * FTC_SBitCache
+ * FTC_SBitCache_New
+ * FTC_SBitCache_Lookup
+ *
+ * FTC_CMapCache
+ * FTC_CMapCache_New
+ * FTC_CMapCache_Lookup
+ *
+ *************************************************************************/
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** BASIC TYPE DEFINITIONS *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+
+
+ /*************************************************************************
+ *
+ * @type: FTC_FaceID
+ *
+ * @description:
+ * An opaque pointer type that is used to identity face objects. The
+ * contents of such objects is application-dependent.
+ *
+ * These pointers are typically used to point to a user-defined
+ * structure containing a font file path, and face index.
+ *
+ * @note:
+ * Never use NULL as a valid @FTC_FaceID.
+ *
+ * Face IDs are passed by the client to the cache manager, which calls,
+ * when needed, the @FTC_Face_Requester to translate them into new
+ * @FT_Face objects.
+ *
+ * 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 @FTC_Manager_RemoveFaceID before any other cache
+ * function.
+ *
+ * Failure to do so will result in incorrect behaviour or even
+ * memory leaks and crashes.
+ */
+ typedef struct FTC_FaceIDRec_* FTC_FaceID;
+
+
+ /************************************************************************
+ *
+ * @functype:
+ * FTC_Face_Requester
+ *
+ * @description:
+ * A callback function provided by client applications. It is used by
+ * the cache manager to translate a given @FTC_FaceID into a new valid
+ * @FT_Face object, on demand.
+ *
+ * <Input>
+ * face_id ::
+ * The face ID to resolve.
+ *
+ * library ::
+ * A handle to a FreeType library object.
+ *
+ * req_data ::
+ * Application-provided request data (see note below).
+ *
+ * <Output>
+ * aface ::
+ * A new @FT_Face handle.
+ *
+ * <Return>
+ * FreeType error code. 0 means success.
+ *
+ * <Note>
+ * The third parameter `req_data' is the same as the one passed by the
+ * client when @FTC_Manager_New is called.
+ *
+ * The face requester should not perform funny things on the returned
+ * face object, like creating a new @FT_Size for it, or setting a
+ * transformation through @FT_Set_Transform!
+ */
+ typedef FT_Error
+ (*FTC_Face_Requester)( FTC_FaceID face_id,
+ FT_Library library,
+ FT_Pointer request_data,
+ FT_Face* aface );
+
+ /* */
+
+#define FT_POINTER_TO_ULONG( p ) ( (FT_ULong)(FT_Pointer)(p) )
+
+#define FTC_FACE_ID_HASH( i ) \
+ ((FT_UInt32)(( FT_POINTER_TO_ULONG( i ) >> 3 ) ^ \
+ ( FT_POINTER_TO_ULONG( i ) << 7 ) ) )
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** CACHE MANAGER OBJECT *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+
+
+ /*************************************************************************/
+ /* */
+ /* <Type> */
+ /* FTC_Manager */
+ /* */
+ /* <Description> */
+ /* This object corresponds to one instance of the cache-subsystem. */
+ /* It is used to cache one or more @FT_Face objects, along with */
+ /* corresponding @FT_Size objects. */
+ /* */
+ /* The manager intentionally limits the total number of opened */
+ /* @FT_Face and @FT_Size objects to control memory usage. See the */
+ /* `max_faces' and `max_sizes' parameters of @FTC_Manager_New. */
+ /* */
+ /* The manager is also used to cache `nodes' of various types while */
+ /* limiting their total memory usage. */
+ /* */
+ /* 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. */
+ /* */
+ typedef struct FTC_ManagerRec_* FTC_Manager;
+
+
+ /*************************************************************************/
+ /* */
+ /* <Type> */
+ /* FTC_Node */
+ /* */
+ /* <Description> */
+ /* 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. */
+ /* */
+ /* If you lookup 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 @FTC_Node_Unref). */
+ /* */
+ /* See also @FTC_SBitCache_Lookup and @FTC_ImageCache_Lookup. */
+ /* */
+ typedef struct FTC_NodeRec_* FTC_Node;
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_Manager_New */
+ /* */
+ /* <Description> */
+ /* Creates a new cache manager. */
+ /* */
+ /* <Input> */
+ /* library :: The parent FreeType library handle to use. */
+ /* */
+ /* max_faces :: Maximum number of opened @FT_Face objects managed by */
+ /* this cache instance. Use 0 for defaults. */
+ /* */
+ /* max_sizes :: Maximum number of opened @FT_Size objects managed by */
+ /* this cache instance. Use 0 for defaults. */
+ /* */
+ /* max_bytes :: Maximum number of bytes to use for cached data nodes. */
+ /* Use 0 for defaults. Note that this value does not */
+ /* account for managed @FT_Face and @FT_Size objects. */
+ /* */
+ /* requester :: An application-provided callback used to translate */
+ /* face IDs into real @FT_Face objects. */
+ /* */
+ /* req_data :: A generic pointer that is passed to the requester */
+ /* each time it is called (see @FTC_Face_Requester). */
+ /* */
+ /* <Output> */
+ /* amanager :: A handle to a new manager object. 0 in case of */
+ /* failure. */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_Manager_New( FT_Library library,
+ FT_UInt max_faces,
+ FT_UInt max_sizes,
+ FT_ULong max_bytes,
+ FTC_Face_Requester requester,
+ FT_Pointer req_data,
+ FTC_Manager *amanager );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_Manager_Reset */
+ /* */
+ /* <Description> */
+ /* Empties a given cache manager. This simply gets rid of all the */
+ /* currently cached @FT_Face and @FT_Size objects within the manager. */
+ /* */
+ /* <InOut> */
+ /* manager :: A handle to the manager. */
+ /* */
+ FT_EXPORT( void )
+ FTC_Manager_Reset( FTC_Manager manager );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_Manager_Done */
+ /* */
+ /* <Description> */
+ /* Destroys a given manager after emptying it. */
+ /* */
+ /* <Input> */
+ /* manager :: A handle to the target cache manager object. */
+ /* */
+ FT_EXPORT( void )
+ FTC_Manager_Done( FTC_Manager manager );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_Manager_LookupFace */
+ /* */
+ /* <Description> */
+ /* Retrieves the @FT_Face object that corresponds to a given face ID */
+ /* through a cache manager. */
+ /* */
+ /* <Input> */
+ /* manager :: A handle to the cache manager. */
+ /* */
+ /* face_id :: The ID of the face object. */
+ /* */
+ /* <Output> */
+ /* aface :: A handle to the face object. */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ /* <Note> */
+ /* The returned @FT_Face object is always owned by the manager. You */
+ /* should never try to discard it yourself. */
+ /* */
+ /* The @FT_Face object doesn't necessarily have a current size object */
+ /* (i.e., face->size can be 0). If you need a specific `font size', */
+ /* use @FTC_Manager_LookupSize instead. */
+ /* */
+ /* Never change the face's transformation matrix (i.e., never call */
+ /* the @FT_Set_Transform function) on a returned face! If you need */
+ /* to transform glyphs, do it yourself after glyph loading. */
+ /* */
+ /* When you perform a lookup, out-of-memory errors are detected */
+ /* _within_ the lookup and force incremental flushes of the cache */
+ /* until enough memory is released for the lookup to succeed. */
+ /* */
+ /* 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. */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_Manager_LookupFace( FTC_Manager manager,
+ FTC_FaceID face_id,
+ FT_Face *aface );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Struct> */
+ /* FTC_ScalerRec */
+ /* */
+ /* <Description> */
+ /* A structure used to describe a given character size in either */
+ /* pixels or points to the cache manager. See */
+ /* @FTC_Manager_LookupSize. */
+ /* */
+ /* <Fields> */
+ /* face_id :: The source face ID. */
+ /* */
+ /* width :: The character width. */
+ /* */
+ /* height :: The character height. */
+ /* */
+ /* pixel :: 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. */
+ /* */
+ /* x_res :: Only used when `pixel' is value 0 to indicate the */
+ /* horizontal resolution in dpi. */
+ /* */
+ /* y_res :: Only used when `pixel' is value 0 to indicate the */
+ /* vertical resolution in dpi. */
+ /* */
+ /* <Note> */
+ /* This type is mainly used to retrieve @FT_Size objects through the */
+ /* cache manager. */
+ /* */
+ typedef struct FTC_ScalerRec_
+ {
+ FTC_FaceID face_id;
+ FT_UInt width;
+ FT_UInt height;
+ FT_Int pixel;
+ FT_UInt x_res;
+ FT_UInt y_res;
+
+ } FTC_ScalerRec, *FTC_Scaler;
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_Manager_LookupSize */
+ /* */
+ /* <Description> */
+ /* Retrieve the @FT_Size object that corresponds to a given */
+ /* @FTC_ScalerRec pointer through a cache manager. */
+ /* */
+ /* <Input> */
+ /* manager :: A handle to the cache manager. */
+ /* */
+ /* scaler :: A scaler handle. */
+ /* */
+ /* <Output> */
+ /* asize :: A handle to the size object. */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ /* <Note> */
+ /* The returned @FT_Size object is always owned by the manager. You */
+ /* should never try to discard it by yourself. */
+ /* */
+ /* You can access the parent @FT_Face object simply as `size->face' */
+ /* if you need it. Note that this object is also owned by the */
+ /* manager. */
+ /* */
+ /* <Note> */
+ /* When you perform a lookup, out-of-memory errors are detected */
+ /* _within_ the lookup and force incremental flushes of the cache */
+ /* until enough memory is released for the lookup to succeed. */
+ /* */
+ /* 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. */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_Manager_LookupSize( FTC_Manager manager,
+ FTC_Scaler scaler,
+ FT_Size *asize );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_Node_Unref */
+ /* */
+ /* <Description> */
+ /* Decrement a cache node's internal reference count. When the count */
+ /* reaches 0, it is not destroyed but becomes eligible for subsequent */
+ /* cache flushes. */
+ /* */
+ /* <Input> */
+ /* node :: The cache node handle. */
+ /* */
+ /* manager :: The cache manager handle. */
+ /* */
+ FT_EXPORT( void )
+ FTC_Node_Unref( FTC_Node node,
+ FTC_Manager manager );
+
+
+ /*************************************************************************
+ *
+ * @function:
+ * FTC_Manager_RemoveFaceID
+ *
+ * @description:
+ * A special function used to indicate to the cache manager that
+ * a given @FTC_FaceID is no longer valid, either because its
+ * content changed, or because it was deallocated or uninstalled.
+ *
+ * @input:
+ * manager ::
+ * The cache manager handle.
+ *
+ * face_id ::
+ * The @FTC_FaceID to be removed.
+ *
+ * @note:
+ * This function flushes all nodes from the cache corresponding to this
+ * `face_id', with the exception of nodes with a non-null reference
+ * count.
+ *
+ * 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.
+ *
+ */
+ FT_EXPORT( void )
+ FTC_Manager_RemoveFaceID( FTC_Manager manager,
+ FTC_FaceID face_id );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Section> */
+ /* cache_subsystem */
+ /* */
+ /*************************************************************************/
+
+ /*************************************************************************
+ *
+ * @type:
+ * FTC_CMapCache
+ *
+ * @description:
+ * An opaque handle used to model a charmap cache. This cache is to
+ * hold character codes -> glyph indices mappings.
+ *
+ */
+ typedef struct FTC_CMapCacheRec_* FTC_CMapCache;
+
+
+ /*************************************************************************
+ *
+ * @function:
+ * FTC_CMapCache_New
+ *
+ * @description:
+ * Create a new charmap cache.
+ *
+ * @input:
+ * manager ::
+ * A handle to the cache manager.
+ *
+ * @output:
+ * acache ::
+ * A new cache handle. NULL in case of error.
+ *
+ * @return:
+ * FreeType error code. 0 means success.
+ *
+ * @note:
+ * Like all other caches, this one will be destroyed with the cache
+ * manager.
+ *
+ */
+ FT_EXPORT( FT_Error )
+ FTC_CMapCache_New( FTC_Manager manager,
+ FTC_CMapCache *acache );
+
+
+ /************************************************************************
+ *
+ * @function:
+ * FTC_CMapCache_Lookup
+ *
+ * @description:
+ * Translate a character code into a glyph index, using the charmap
+ * cache.
+ *
+ * @input:
+ * cache ::
+ * A charmap cache handle.
+ *
+ * face_id ::
+ * The source face ID.
+ *
+ * cmap_index ::
+ * The index of the charmap in the source face.
+ *
+ * char_code ::
+ * The character code (in the corresponding charmap).
+ *
+ * @return:
+ * Glyph index. 0 means `no glyph'.
+ *
+ */
+ FT_EXPORT( FT_UInt )
+ FTC_CMapCache_Lookup( FTC_CMapCache cache,
+ FTC_FaceID face_id,
+ FT_Int cmap_index,
+ FT_UInt32 char_code );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Section> */
+ /* cache_subsystem */
+ /* */
+ /*************************************************************************/
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+ /***** *****/
+ /***** IMAGE CACHE OBJECT *****/
+ /***** *****/
+ /*************************************************************************/
+ /*************************************************************************/
+ /*************************************************************************/
+
+
+ /*************************************************************************
+ *
+ * @struct:
+ * FTC_ImageTypeRec
+ *
+ * @description:
+ * A structure used to model the type of images in a glyph cache.
+ *
+ * @fields:
+ * face_id ::
+ * The face ID.
+ *
+ * width ::
+ * The width in pixels.
+ *
+ * height ::
+ * The height in pixels.
+ *
+ * flags ::
+ * The load flags, as in @FT_Load_Glyph.
+ *
+ */
+ typedef struct FTC_ImageTypeRec_
+ {
+ FTC_FaceID face_id;
+ FT_Int width;
+ FT_Int height;
+ FT_Int32 flags;
+
+ } FTC_ImageTypeRec;
+
+
+ /*************************************************************************
+ *
+ * @type:
+ * FTC_ImageType
+ *
+ * @description:
+ * A handle to an @FTC_ImageTypeRec structure.
+ *
+ */
+ typedef struct FTC_ImageTypeRec_* FTC_ImageType;
+
+
+ /* */
+
+
+#define FTC_IMAGE_TYPE_COMPARE( d1, d2 ) \
+ ( (d1)->face_id == (d2)->face_id && \
+ (d1)->width == (d2)->width && \
+ (d1)->flags == (d2)->flags )
+
+#define FTC_IMAGE_TYPE_HASH( d ) \
+ (FT_UFast)( FTC_FACE_ID_HASH( (d)->face_id ) ^ \
+ ( (d)->width << 8 ) ^ (d)->height ^ \
+ ( (d)->flags << 4 ) )
+
+
+ /*************************************************************************/
+ /* */
+ /* <Type> */
+ /* FTC_ImageCache */
+ /* */
+ /* <Description> */
+ /* A handle to an glyph image cache object. They are designed to */
+ /* hold many distinct glyph images while not exceeding a certain */
+ /* memory threshold. */
+ /* */
+ typedef struct FTC_ImageCacheRec_* FTC_ImageCache;
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_ImageCache_New */
+ /* */
+ /* <Description> */
+ /* Creates a new glyph image cache. */
+ /* */
+ /* <Input> */
+ /* manager :: The parent manager for the image cache. */
+ /* */
+ /* <Output> */
+ /* acache :: A handle to the new glyph image cache object. */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_ImageCache_New( FTC_Manager manager,
+ FTC_ImageCache *acache );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_ImageCache_Lookup */
+ /* */
+ /* <Description> */
+ /* Retrieves a given glyph image from a glyph image cache. */
+ /* */
+ /* <Input> */
+ /* cache :: A handle to the source glyph image cache. */
+ /* */
+ /* type :: A pointer to a glyph image type descriptor. */
+ /* */
+ /* gindex :: The glyph index to retrieve. */
+ /* */
+ /* <Output> */
+ /* aglyph :: The corresponding @FT_Glyph object. 0 in case of */
+ /* failure. */
+ /* */
+ /* anode :: Used to return the address of of the corresponding cache */
+ /* node after incrementing its reference count (see note */
+ /* below). */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ /* <Note> */
+ /* 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 @FT_Glyph_Copy and modify the new one. */
+ /* */
+ /* If `anode' is _not_ 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 @FT_Glyph) will */
+ /* always be kept in the cache until you call @FTC_Node_Unref to */
+ /* `release' it. */
+ /* */
+ /* If `anode' is NULL, the cache node is left unchanged, which means */
+ /* that the @FT_Glyph 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! */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_ImageCache_Lookup( FTC_ImageCache cache,
+ FTC_ImageType type,
+ FT_UInt gindex,
+ FT_Glyph *aglyph,
+ FTC_Node *anode );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_ImageCache_LookupScaler */
+ /* */
+ /* <Description> */
+ /* A variant of @FTC_ImageCache_Lookup that uses an @FTC_ScalerRec */
+ /* to specify the face ID and its size. */
+ /* */
+ /* <Input> */
+ /* cache :: A handle to the source glyph image cache. */
+ /* */
+ /* scaler :: A pointer to a scaler descriptor. */
+ /* */
+ /* load_flags :: The corresponding load flags. */
+ /* */
+ /* gindex :: The glyph index to retrieve. */
+ /* */
+ /* <Output> */
+ /* aglyph :: The corresponding @FT_Glyph object. 0 in case of */
+ /* failure. */
+ /* */
+ /* anode :: Used to return the address of of the corresponding */
+ /* cache node after incrementing its reference count */
+ /* (see note below). */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ /* <Note> */
+ /* 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 @FT_Glyph_Copy and modify the new one. */
+ /* */
+ /* If `anode' is _not_ 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 @FT_Glyph) will */
+ /* always be kept in the cache until you call @FTC_Node_Unref to */
+ /* `release' it. */
+ /* */
+ /* If `anode' is NULL, the cache node is left unchanged, which means */
+ /* that the @FT_Glyph 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! */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_ImageCache_LookupScaler( FTC_ImageCache cache,
+ FTC_Scaler scaler,
+ FT_ULong load_flags,
+ FT_UInt gindex,
+ FT_Glyph *aglyph,
+ FTC_Node *anode );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Type> */
+ /* FTC_SBit */
+ /* */
+ /* <Description> */
+ /* A handle to a small bitmap descriptor. See the @FTC_SBitRec */
+ /* structure for details. */
+ /* */
+ typedef struct FTC_SBitRec_* FTC_SBit;
+
+
+ /*************************************************************************/
+ /* */
+ /* <Struct> */
+ /* FTC_SBitRec */
+ /* */
+ /* <Description> */
+ /* A very compact structure used to describe a small glyph bitmap. */
+ /* */
+ /* <Fields> */
+ /* width :: The bitmap width in pixels. */
+ /* */
+ /* height :: The bitmap height in pixels. */
+ /* */
+ /* left :: The horizontal distance from the pen position to the */
+ /* left bitmap border (a.k.a. `left side bearing', or */
+ /* `lsb'). */
+ /* */
+ /* top :: 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. */
+ /* */
+ /* format :: The format of the glyph bitmap (monochrome or gray). */
+ /* */
+ /* max_grays :: Maximum gray level value (in the range 1 to 255). */
+ /* */
+ /* pitch :: The number of bytes per bitmap line. May be positive */
+ /* or negative. */
+ /* */
+ /* xadvance :: The horizontal advance width in pixels. */
+ /* */
+ /* yadvance :: The vertical advance height in pixels. */
+ /* */
+ /* buffer :: A pointer to the bitmap pixels. */
+ /* */
+ typedef struct FTC_SBitRec_
+ {
+ FT_Byte width;
+ FT_Byte height;
+ FT_Char left;
+ FT_Char top;
+
+ FT_Byte format;
+ FT_Byte max_grays;
+ FT_Short pitch;
+ FT_Char xadvance;
+ FT_Char yadvance;
+
+ FT_Byte* buffer;
+
+ } FTC_SBitRec;
+
+
+ /*************************************************************************/
+ /* */
+ /* <Type> */
+ /* FTC_SBitCache */
+ /* */
+ /* <Description> */
+ /* 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 @FTC_ImageCache. */
+ /* */
+ typedef struct FTC_SBitCacheRec_* FTC_SBitCache;
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_SBitCache_New */
+ /* */
+ /* <Description> */
+ /* Creates a new cache to store small glyph bitmaps. */
+ /* */
+ /* <Input> */
+ /* manager :: A handle to the source cache manager. */
+ /* */
+ /* <Output> */
+ /* acache :: A handle to the new sbit cache. NULL in case of error. */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_SBitCache_New( FTC_Manager manager,
+ FTC_SBitCache *acache );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_SBitCache_Lookup */
+ /* */
+ /* <Description> */
+ /* Looks up a given small glyph bitmap in a given sbit cache and */
+ /* `lock' it to prevent its flushing from the cache until needed. */
+ /* */
+ /* <Input> */
+ /* cache :: A handle to the source sbit cache. */
+ /* */
+ /* type :: A pointer to the glyph image type descriptor. */
+ /* */
+ /* gindex :: The glyph index. */
+ /* */
+ /* <Output> */
+ /* sbit :: A handle to a small bitmap descriptor. */
+ /* */
+ /* anode :: Used to return the address of of the corresponding cache */
+ /* node after incrementing its reference count (see note */
+ /* below). */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ /* <Note> */
+ /* 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. */
+ /* */
+ /* The descriptor's `buffer' field is set to 0 to indicate a missing */
+ /* glyph bitmap. */
+ /* */
+ /* If `anode' is _not_ 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 @FTC_Node_Unref to `release' it. */
+ /* */
+ /* 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! */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_SBitCache_Lookup( FTC_SBitCache cache,
+ FTC_ImageType type,
+ FT_UInt gindex,
+ FTC_SBit *sbit,
+ FTC_Node *anode );
+
+
+ /*************************************************************************/
+ /* */
+ /* <Function> */
+ /* FTC_SBitCache_LookupScaler */
+ /* */
+ /* <Description> */
+ /* A variant of @FTC_SBitCache_Lookup that uses an @FTC_ScalerRec */
+ /* to specify the face ID and its size. */
+ /* */
+ /* <Input> */
+ /* cache :: A handle to the source sbit cache. */
+ /* */
+ /* scaler :: A pointer to the scaler descriptor. */
+ /* */
+ /* load_flags :: The corresponding load flags. */
+ /* */
+ /* gindex :: The glyph index. */
+ /* */
+ /* <Output> */
+ /* sbit :: A handle to a small bitmap descriptor. */
+ /* */
+ /* anode :: Used to return the address of of the corresponding */
+ /* cache node after incrementing its reference count */
+ /* (see note below). */
+ /* */
+ /* <Return> */
+ /* FreeType error code. 0 means success. */
+ /* */
+ /* <Note> */
+ /* 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. */
+ /* */
+ /* The descriptor's `buffer' field is set to 0 to indicate a missing */
+ /* glyph bitmap. */
+ /* */
+ /* If `anode' is _not_ 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 @FTC_Node_Unref to `release' it. */
+ /* */
+ /* 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! */
+ /* */
+ FT_EXPORT( FT_Error )
+ FTC_SBitCache_LookupScaler( FTC_SBitCache cache,
+ FTC_Scaler scaler,
+ FT_ULong load_flags,
+ FT_UInt gindex,
+ FTC_SBit *sbit,
+ FTC_Node *anode );
+
+
+ /* */
+
+#ifdef FT_CONFIG_OPTION_OLD_INTERNALS
+
+ /*@***********************************************************************/
+ /* */
+ /* <Struct> */
+ /* FTC_FontRec */
+ /* */
+ /* <Description> */
+ /* A simple structure used to describe a given `font' to the cache */
+ /* manager. Note that a `font' is the combination of a given face */
+ /* with a given character size. */
+ /* */
+ /* <Fields> */
+ /* face_id :: The ID of the face to use. */
+ /* */
+ /* pix_width :: The character width in integer pixels. */
+ /* */
+ /* pix_height :: The character height in integer pixels. */
+ /* */
+ typedef struct FTC_FontRec_
+ {
+ FTC_FaceID face_id;
+ FT_UShort pix_width;
+ FT_UShort pix_height;
+
+ } FTC_FontRec;
+
+
+ /* */
+
+
+#define FTC_FONT_COMPARE( f1, f2 ) \
+ ( (f1)->face_id == (f2)->face_id && \
+ (f1)->pix_width == (f2)->pix_width && \
+ (f1)->pix_height == (f2)->pix_height )
+
+#define FTC_FONT_HASH( f ) \
+ (FT_UInt32)( FTC_FACE_ID_HASH((f)->face_id) ^ \
+ ((f)->pix_width << 8) ^ \
+ ((f)->pix_height) )
+
+ typedef FTC_FontRec* FTC_Font;
+
+
+ FT_EXPORT( FT_Error )
+ FTC_Manager_Lookup_Face( FTC_Manager manager,
+ FTC_FaceID face_id,
+ FT_Face *aface );
+
+ FT_EXPORT( FT_Error )
+ FTC_Manager_Lookup_Size( FTC_Manager manager,
+ FTC_Font font,
+ FT_Face *aface,
+ FT_Size *asize );
+
+#endif /* FT_CONFIG_OPTION_OLD_INTERNALS */
+
+
+ /* */
+
+FT_END_HEADER
+
+#endif /* __FTCACHE_H__ */
+
+
+/* END */