📄 ftcache.h
字号:
/* 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;
/*************************************************************************
*
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -