838 lines
48 KiB
C
838 lines
48 KiB
C
/***************************************************************************/
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/* */
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/* ftcache.h */
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/* */
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/* FreeType Cache subsystem (specification). */
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/* */
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/* Copyright 1996-2001, 2002, 2003, 2004, 2005 by */
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */
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/* */
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/* This file is part of the FreeType project, and may only be used, */
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/* modified, and distributed under the terms of the FreeType project */
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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/* this file you indicate that you have read the license and */
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/* understand and accept it fully. */
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/* */
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/***************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/********* *********/
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/********* WARNING, THIS IS BETA CODE. *********/
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/********* *********/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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#ifndef __FTCACHE_H__
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#define __FTCACHE_H__
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#include <ft2build.h>
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#include FT_GLYPH_H
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FT_BEGIN_HEADER
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/*************************************************************************/
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/* */
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/* <Section> */
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/* cache_subsystem */
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/* */
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/* <Title> */
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/* Cache Sub-System */
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/* */
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/* <Abstract> */
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/* How to cache face, size, and glyph data with FreeType 2. */
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/* */
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/* <Description> */
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/* This section describes the FreeType 2 cache sub-system which is */
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/* still in beta. */
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/* */
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/* <Order> */
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/* FTC_Manager */
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/* FTC_FaceID */
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/* FTC_Face_Requester */
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/* */
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/* FTC_Manager_New */
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/* FTC_Manager_Reset */
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/* FTC_Manager_Done */
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/* FTC_Manager_LookupFace */
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/* FTC_Manager_LookupSize */
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/* FTC_Manager_RemoveFaceID */
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/* */
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/* FTC_Node */
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/* FTC_Node_Unref */
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/* */
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/* FTC_Font */
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/* FTC_ImageCache */
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/* FTC_ImageCache_New */
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/* FTC_ImageCache_Lookup */
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/* */
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/* FTC_SBit */
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/* FTC_SBitCache */
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/* FTC_SBitCache_New */
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/* FTC_SBitCache_Lookup */
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/* */
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/* FTC_CMapCache */
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/* FTC_CMapCache_New */
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/* FTC_CMapCache_Lookup */
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/* */
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/***** *****/
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/***** BASIC TYPE DEFINITIONS *****/
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/***** *****/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/* */
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/* <Type> */
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/* FTC_FaceID */
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/* */
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/* <Description> */
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/* An opaque pointer type that is used to identity face objects. The */
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/* contents of such objects is application-dependent. */
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/* */
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typedef struct FTC_FaceIDRec_* FTC_FaceID;
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/*************************************************************************/
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/* */
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/* <FuncType> */
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/* FTC_Face_Requester */
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/* */
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/* <Description> */
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/* A callback function provided by client applications. It is used */
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/* to translate a given @FTC_FaceID into a new valid @FT_Face object. */
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/* */
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/* <Input> */
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/* face_id :: The face ID to resolve. */
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/* */
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/* library :: A handle to a FreeType library object. */
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/* */
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/* data :: Application-provided request data. */
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/* */
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/* <Output> */
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/* aface :: A new @FT_Face handle. */
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/* */
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/* <Return> */
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/* FreeType error code. 0 means success. */
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/* */
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/* <Note> */
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/* The face requester should not perform funny things on the returned */
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/* face object, like creating a new @FT_Size for it, or setting a */
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/* transformation through @FT_Set_Transform! */
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/* */
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typedef FT_Error
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(*FTC_Face_Requester)( FTC_FaceID face_id,
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FT_Library library,
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FT_Pointer request_data,
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FT_Face* aface );
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/*************************************************************************/
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/* */
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/* <Struct> */
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/* FTC_FontRec */
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/* */
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/* <Description> */
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/* A simple structure used to describe a given `font' to the cache */
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/* manager. Note that a `font' is the combination of a given face */
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/* with a given character size. */
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/* */
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/* <Fields> */
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/* face_id :: The ID of the face to use. */
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/* */
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/* pix_width :: The character width in integer pixels. */
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/* */
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/* pix_height :: The character height in integer pixels. */
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/* */
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typedef struct FTC_FontRec_
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{
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FTC_FaceID face_id;
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FT_UShort pix_width;
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FT_UShort pix_height;
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} FTC_FontRec;
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/* */
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#define FTC_FONT_COMPARE( f1, f2 ) \
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( (f1)->face_id == (f2)->face_id && \
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(f1)->pix_width == (f2)->pix_width && \
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(f1)->pix_height == (f2)->pix_height )
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#define FT_POINTER_TO_ULONG( p ) ((FT_ULong)(FT_Pointer)(p))
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#define FTC_FACE_ID_HASH( i ) \
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((FT_UInt32)(( FT_POINTER_TO_ULONG( i ) >> 3 ) ^ \
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( FT_POINTER_TO_ULONG( i ) << 7 ) ) )
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#define FTC_FONT_HASH( f ) \
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(FT_UInt32)( FTC_FACE_ID_HASH((f)->face_id) ^ \
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((f)->pix_width << 8) ^ \
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((f)->pix_height) )
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/*************************************************************************/
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/* */
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/* <Type> */
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/* FTC_Font */
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/* */
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/* <Description> */
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/* A simple handle to an @FTC_FontRec structure. */
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/* */
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typedef FTC_FontRec* FTC_Font;
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/***** *****/
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/***** CACHE MANAGER OBJECT *****/
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/***** *****/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/* */
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/* <Type> */
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/* FTC_Manager */
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/* */
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/* <Description> */
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/* This object is used to cache one or more @FT_Face objects, along */
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/* with corresponding @FT_Size objects. */
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/* */
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typedef struct FTC_ManagerRec_* FTC_Manager;
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/*************************************************************************/
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/* */
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/* <Type> */
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/* FTC_Node */
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/* */
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/* <Description> */
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/* An opaque handle to a cache node object. Each cache node is */
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/* reference-counted. A node with a count of 0 might be flushed */
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/* out of a full cache whenever a lookup request is performed. */
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/* */
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/* If you lookup nodes, you have the ability to "acquire" them, i.e., */
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/* to increment their reference count. This will prevent the node */
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/* from being flushed out of the cache until you explicitly "release" */
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/* it (see @FTC_Node_Unref). */
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/* */
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/* See also @FTC_SBitCache_Lookup and @FTC_ImageCache_Lookup. */
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/* */
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typedef struct FTC_NodeRec_* FTC_Node;
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FTC_Manager_New */
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/* */
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/* <Description> */
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/* Creates a new cache manager. */
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/* */
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/* <Input> */
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/* library :: The parent FreeType library handle to use. */
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/* */
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/* max_bytes :: Maximum number of bytes to use for cached data */
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/* nodes. Use 0 for defaults. Note that this value */
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/* does not account for managed FT_Face and FT_Size */
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/* objects. */
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/* */
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/* requester :: An application-provided callback used to translate */
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/* face IDs into real @FT_Face objects. */
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/* */
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/* req_data :: A generic pointer that is passed to the requester */
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/* each time it is called (see @FTC_Face_Requester). */
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/* */
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/* <Output> */
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/* amanager :: A handle to a new manager object. 0 in case of */
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/* failure. */
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/* */
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/* <Return> */
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/* FreeType error code. 0 means success. */
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/* */
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/* <Note> */
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/* When you perform a lookup, out-of-memory errors are detected */
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/* _within_ the lookup and force incremental flushes of the cache */
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/* until enough memory is released for the lookup to succeed. */
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/* */
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/* If a lookup fails with FT_Err_Out_Of_Memory the cache has already */
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/* been completely flushed, and still no memory is available for the */
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/* operation. */
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/* */
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FT_EXPORT( FT_Error )
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FTC_Manager_New( FT_Library library,
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FT_UInt max_faces,
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FT_UInt max_sizes,
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FT_ULong max_bytes,
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FTC_Face_Requester requester,
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FT_Pointer req_data,
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FTC_Manager *amanager );
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FTC_Manager_Reset */
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/* */
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/* <Description> */
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/* Empties a given cache manager. This simply gets rid of all the */
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/* currently cached @FT_Face and @FT_Size objects within the manager. */
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/* */
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/* <InOut> */
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/* manager :: A handle to the manager. */
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/* */
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FT_EXPORT( void )
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FTC_Manager_Reset( FTC_Manager manager );
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FTC_Manager_Done */
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/* */
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/* <Description> */
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/* Destroys a given manager after emptying it. */
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/* */
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/* <Input> */
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/* manager :: A handle to the target cache manager object. */
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/* */
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FT_EXPORT( void )
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FTC_Manager_Done( FTC_Manager manager );
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FTC_Manager_LookupFace */
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/* */
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/* <Description> */
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/* Retrieves the @FT_Face object that corresponds to a given face ID */
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/* through a cache manager. */
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/* */
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/* <Input> */
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/* manager :: A handle to the cache manager. */
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/* */
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/* face_id :: The ID of the face object. */
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/* */
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/* <Output> */
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/* aface :: A handle to the face object. */
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/* */
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/* <Return> */
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/* FreeType error code. 0 means success. */
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/* */
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/* <Note> */
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/* The returned @FT_Face object is always owned by the manager. You */
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/* should never try to discard it yourself. */
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/* */
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/* The @FT_Face object doesn't necessarily have a current size object */
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/* (i.e., face->size can be 0). If you need a specific `font size', */
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/* use @FTC_Manager_LookupSize instead. */
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/* */
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/* Never change the face's transformation matrix (i.e., never call */
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/* the @FT_Set_Transform function) on a returned face! If you need */
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/* to transform glyphs, do it yourself after glyph loading. */
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/* */
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FT_EXPORT( FT_Error )
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FTC_Manager_LookupFace( FTC_Manager manager,
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FTC_FaceID face_id,
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FT_Face *aface );
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/*************************************************************************/
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/* */
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/* <Struct> */
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/* FTC_ScalerRec */
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/* */
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/* <Description> */
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/* A structure used to describe a given character size in either */
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/* pixels or points to the cache manager. See */
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/* @FTC_Manager_LookupSize. */
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/* */
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/* <Fields> */
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/* face_id :: The source face ID. */
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/* */
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/* width :: The character width. */
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/* */
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/* height :: The character height. */
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/* */
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/* pixel :: A Boolean. If TRUE, the `width' and `height' fields */
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/* are interpreted as integer pixel character sizes. */
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/* Otherwise, they are expressed as 1/64th of points. */
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/* */
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/* x_res :: Only used when `pixel' is FALSE to indicate the */
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/* horizontal resolution in dpi. */
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/* */
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/* y_res :: Only used when `pixel' is FALSE to indicate the */
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/* vertical resolution in dpi. */
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/* */
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/* <Note> */
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/* This type is mainly used to retrieve @FT_Size objects through the */
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/* cache manager. */
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/* */
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typedef struct FTC_ScalerRec_
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{
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FTC_FaceID face_id;
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FT_UInt width;
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FT_UInt height;
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FT_Int pixel;
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FT_UInt x_res;
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FT_UInt y_res;
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} FTC_ScalerRec, *FTC_Scaler;
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FTC_Manager_LookupSize */
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/* */
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/* <Description> */
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/* Retrieve the @FT_Size object that corresponds to a given */
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/* @FTC_Scaler through a cache manager. */
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/* */
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/* <Input> */
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/* manager :: A handle to the cache manager. */
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/* */
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/* scaler :: A scaler handle. */
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/* */
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/* <Output> */
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/* asize :: A handle to the size object. */
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/* */
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/* <Return> */
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/* FreeType error code. 0 means success. */
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/* */
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/* <Note> */
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/* The returned @FT_Size object is always owned by the manager. You */
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/* should never try to discard it by yourself. */
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/* */
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/* You can access the parent @FT_Face object simply as `size->face' */
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/* if you need it. Note that this object is also owned by the */
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/* manager. */
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/* */
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FT_EXPORT( FT_Error )
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FTC_Manager_LookupSize( FTC_Manager manager,
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FTC_Scaler scaler,
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FT_Size *asize );
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/*************************************************************************/
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/* */
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/* <Function> */
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/* FTC_Node_Unref */
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/* */
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/* <Description> */
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/* Decrement a cache node's internal reference count. When the count */
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/* reaches 0, it is not destroyed but becomes eligible for subsequent */
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/* cache flushes. */
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/* */
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/* <Input> */
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/* node :: The cache node handle. */
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/* */
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/* manager :: The cache manager handle. */
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/* */
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FT_EXPORT( void )
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FTC_Node_Unref( FTC_Node node,
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FTC_Manager manager );
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/* remove all nodes belonging to a given face_id */
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FT_EXPORT( void )
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FTC_Manager_RemoveFaceID( FTC_Manager manager,
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FTC_FaceID face_id );
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/*************************************************************************/
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/* */
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/* <Section> */
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/* cache_subsystem */
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/* */
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/*************************************************************************/
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/*************************************************************************
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*
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* @type:
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* FTC_CMapCache
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*
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* @description:
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* An opaque handle used to manager a charmap cache. This cache is to
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* hold character codes -> glyph indices mappings.
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*
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*/
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typedef struct FTC_CMapCacheRec_* FTC_CMapCache;
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/*************************************************************************
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*
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* @function:
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* FTC_CMapCache_New
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*
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* @description:
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* Create a new charmap cache.
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*
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* @input:
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* manager ::
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* A handle to the cache manager.
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*
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* @output:
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* acache ::
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* A new cache handle. NULL in case of error.
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*
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* @return:
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* FreeType error code. 0 means success.
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*
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* @note:
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* Like all other caches, this one will be destroyed with the cache
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* manager.
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*
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*/
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FT_EXPORT( FT_Error )
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FTC_CMapCache_New( FTC_Manager manager,
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FTC_CMapCache *acache );
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/************************************************************************
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*
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* @function:
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* FTC_CMapCache_Lookup
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*
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* @description:
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* Translate a character code into a glyph index, using the charmap
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* cache.
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*
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* @input:
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* cache ::
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* A charmap cache handle.
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*
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* face_id ::
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* The source face ID.
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*
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* cmap_index ::
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* The index of the charmap in the source face.
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*
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* char_code ::
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* The character code (in the corresponding charmap).
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*
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* @return:
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* Glyph index. 0 means `no glyph'.
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*
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*/
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FT_EXPORT( FT_UInt )
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FTC_CMapCache_Lookup( FTC_CMapCache cache,
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FTC_FaceID face_id,
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FT_Int cmap_index,
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FT_UInt32 char_code );
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/*************************************************************************/
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/* */
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/* <Section> */
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/* cache_subsystem */
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/* */
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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/***** *****/
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/***** IMAGE CACHE OBJECT *****/
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/***** *****/
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/*************************************************************************/
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/*************************************************************************/
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/*************************************************************************/
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typedef struct FTC_ImageTypeRec_
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{
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FTC_FaceID face_id;
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FT_Int width;
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FT_Int height;
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FT_Int32 flags;
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} FTC_ImageTypeRec;
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typedef struct FTC_ImageTypeRec_* FTC_ImageType;
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/* */
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#define FTC_IMAGE_TYPE_COMPARE( d1, d2 ) \
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( FTC_FONT_COMPARE( &(d1)->font, &(d2)->font ) && \
|
|
(d1)->flags == (d2)->flags )
|
|
|
|
#define FTC_IMAGE_TYPE_HASH( d ) \
|
|
(FT_UFast)( FTC_FONT_HASH( &(d)->font ) ^ \
|
|
( (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 );
|
|
|
|
|
|
/*************************************************************************/
|
|
/* */
|
|
/* <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 );
|
|
|
|
|
|
/* */
|
|
|
|
FT_END_HEADER
|
|
|
|
#endif /* __FTCACHE_H__ */
|
|
|
|
|
|
/* END */
|