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/***************************************************************************/ |
/* */ |
/* ftcmanag.h */ |
/* */ |
/* FreeType Cache Manager (specification). */ |
/* */ |
/* Copyright 2000-2001, 2003, 2004, 2006, 2010, 2013 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. */ |
/* */ |
/***************************************************************************/ |
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/*************************************************************************/ |
/* */ |
/* A cache manager is in charge of the following: */ |
/* */ |
/* - Maintain a mapping between generic FTC_FaceIDs and live FT_Face */ |
/* objects. The mapping itself is performed through a user-provided */ |
/* callback. However, the manager maintains a small cache of FT_Face */ |
/* and FT_Size objects in order to speed up things considerably. */ |
/* */ |
/* - Manage one or more cache objects. Each cache is in charge of */ |
/* holding a varying number of `cache nodes'. Each cache node */ |
/* represents a minimal amount of individually accessible cached */ |
/* data. For example, a cache node can be an FT_Glyph image */ |
/* containing a vector outline, or some glyph metrics, or anything */ |
/* else. */ |
/* */ |
/* Each cache node has a certain size in bytes that is added to the */ |
/* total amount of `cache memory' within the manager. */ |
/* */ |
/* All cache nodes are located in a global LRU list, where the oldest */ |
/* node is at the tail of the list. */ |
/* */ |
/* Each node belongs to a single cache, and includes a reference */ |
/* count to avoid destroying it (due to caching). */ |
/* */ |
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/*************************************************************************/ |
/********* *********/ |
/********* WARNING, THIS IS BETA CODE. *********/ |
/********* *********/ |
/*************************************************************************/ |
/*************************************************************************/ |
/*************************************************************************/ |
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#ifndef __FTCMANAG_H__ |
#define __FTCMANAG_H__ |
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#include <ft2build.h> |
#include FT_CACHE_H |
#include "ftcmru.h" |
#include "ftccache.h" |
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FT_BEGIN_HEADER |
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/*************************************************************************/ |
/* */ |
/* <Section> */ |
/* cache_subsystem */ |
/* */ |
/*************************************************************************/ |
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#define FTC_MAX_FACES_DEFAULT 2 |
#define FTC_MAX_SIZES_DEFAULT 4 |
#define FTC_MAX_BYTES_DEFAULT 200000L /* ~200kByte by default */ |
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/* maximum number of caches registered in a single manager */ |
#define FTC_MAX_CACHES 16 |
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typedef struct FTC_ManagerRec_ |
{ |
FT_Library library; |
FT_Memory memory; |
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FTC_Node nodes_list; |
FT_Offset max_weight; |
FT_Offset cur_weight; |
FT_UInt num_nodes; |
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FTC_Cache caches[FTC_MAX_CACHES]; |
FT_UInt num_caches; |
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FTC_MruListRec faces; |
FTC_MruListRec sizes; |
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FT_Pointer request_data; |
FTC_Face_Requester request_face; |
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} FTC_ManagerRec; |
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/*************************************************************************/ |
/* */ |
/* <Function> */ |
/* FTC_Manager_Compress */ |
/* */ |
/* <Description> */ |
/* This function is used to check the state of the cache manager if */ |
/* its `num_bytes' field is greater than its `max_bytes' field. It */ |
/* will flush as many old cache nodes as possible (ignoring cache */ |
/* nodes with a non-zero reference count). */ |
/* */ |
/* <InOut> */ |
/* manager :: A handle to the cache manager. */ |
/* */ |
/* <Note> */ |
/* Client applications should not call this function directly. It is */ |
/* normally invoked by specific cache implementations. */ |
/* */ |
/* The reason this function is exported is to allow client-specific */ |
/* cache classes. */ |
/* */ |
FT_LOCAL( void ) |
FTC_Manager_Compress( FTC_Manager manager ); |
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/* try to flush `count' old nodes from the cache; return the number |
* of really flushed nodes |
*/ |
FT_LOCAL( FT_UInt ) |
FTC_Manager_FlushN( FTC_Manager manager, |
FT_UInt count ); |
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/* this must be used internally for the moment */ |
FT_LOCAL( FT_Error ) |
FTC_Manager_RegisterCache( FTC_Manager manager, |
FTC_CacheClass clazz, |
FTC_Cache *acache ); |
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/* */ |
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#define FTC_SCALER_COMPARE( a, b ) \ |
( (a)->face_id == (b)->face_id && \ |
(a)->width == (b)->width && \ |
(a)->height == (b)->height && \ |
((a)->pixel != 0) == ((b)->pixel != 0) && \ |
( (a)->pixel || \ |
( (a)->x_res == (b)->x_res && \ |
(a)->y_res == (b)->y_res ) ) ) |
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#define FTC_SCALER_HASH( q ) \ |
( _FTC_FACE_ID_HASH( (q)->face_id ) + \ |
(q)->width + (q)->height*7 + \ |
( (q)->pixel ? 0 : ( (q)->x_res*33 ^ (q)->y_res*61 ) ) ) |
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/* */ |
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FT_END_HEADER |
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#endif /* __FTCMANAG_H__ */ |
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/* END */ |