| /***************************************************************************/ |
| /* */ |
| /* ftcache.h */ |
| /* */ |
| /* FreeType Cache subsystem (specification). */ |
| /* */ |
| /* Copyright 1996-2015 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 an @FTC_FaceID into a new @FT_Face object. The latter is |
| * then completely managed by the cache, including its termination |
| * through @FT_Done_Face. To monitor termination of face objects, the |
| * finalizer callback in the `generic' field of the @FT_Face object can |
| * be used, which might also be used to store the @FTC_FaceID of the |
| * 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 that 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 FT_Pointer 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 req_data, |
| FT_Face* aface ); |
| |
| /* */ |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /***** *****/ |
| /***** 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 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 @FTC_Node_Unref). */ |
| /* */ |
| /* See also @FTC_SBitCache_Lookup and @FTC_ImageCache_Lookup. */ |
| /* */ |
| typedef struct FTC_NodeRec_* FTC_Node; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* FTC_Manager_New */ |
| /* */ |
| /* <Description> */ |
| /* Create 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> */ |
| /* Empty 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> */ |
| /* Destroy 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> */ |
| /* Retrieve 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; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Struct> */ |
| /* FTC_Scaler */ |
| /* */ |
| /* <Description> */ |
| /* A handle to an @FTC_ScalerRec structure. */ |
| /* */ |
| typedef struct 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. Any negative value |
| * means to use the cache @FT_Face's default charmap. |
| * |
| * 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_UInt width; |
| FT_UInt 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 ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Type> */ |
| /* FTC_ImageCache */ |
| /* */ |
| /* <Description> */ |
| /* A handle to a 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> */ |
| /* Create 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> */ |
| /* Retrieve 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! */ |
| /* */ |
| /* Calls to @FT_Set_Char_Size and friends have no effect on cached */ |
| /* glyphs; you should always use the FreeType cache API instead. */ |
| /* */ |
| 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> */ |
| /* Create 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> */ |
| /* Look 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 ); |
| |
| /* */ |
| |
| |
| FT_END_HEADER |
| |
| #endif /* __FTCACHE_H__ */ |
| |
| |
| /* END */ |
