| /***************************************************************************/ |
| /* */ |
| /* ftcmanag.h */ |
| /* */ |
| /* FreeType Cache Manager (specification). */ |
| /* */ |
| /* Copyright 2000-2015 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. */ |
| /* */ |
| /***************************************************************************/ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* 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). */ |
| /* */ |
| /*************************************************************************/ |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /********* *********/ |
| /********* WARNING, THIS IS BETA CODE. *********/ |
| /********* *********/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| #ifndef __FTCMANAG_H__ |
| #define __FTCMANAG_H__ |
| |
| |
| #include <ft2build.h> |
| #include FT_CACHE_H |
| #include "ftcmru.h" |
| #include "ftccache.h" |
| |
| |
| FT_BEGIN_HEADER |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Section> */ |
| /* cache_subsystem */ |
| /* */ |
| /*************************************************************************/ |
| |
| |
| #define FTC_MAX_FACES_DEFAULT 2 |
| #define FTC_MAX_SIZES_DEFAULT 4 |
| #define FTC_MAX_BYTES_DEFAULT 200000L /* ~200kByte by default */ |
| |
| /* maximum number of caches registered in a single manager */ |
| #define FTC_MAX_CACHES 16 |
| |
| |
| typedef struct FTC_ManagerRec_ |
| { |
| FT_Library library; |
| FT_Memory memory; |
| |
| FTC_Node nodes_list; |
| FT_Offset max_weight; |
| FT_Offset cur_weight; |
| FT_UInt num_nodes; |
| |
| FTC_Cache caches[FTC_MAX_CACHES]; |
| FT_UInt num_caches; |
| |
| FTC_MruListRec faces; |
| FTC_MruListRec sizes; |
| |
| FT_Pointer request_data; |
| FTC_Face_Requester request_face; |
| |
| } FTC_ManagerRec; |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <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 ); |
| |
| |
| /* 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 ); |
| |
| |
| /* this must be used internally for the moment */ |
| FT_LOCAL( FT_Error ) |
| FTC_Manager_RegisterCache( FTC_Manager manager, |
| FTC_CacheClass clazz, |
| FTC_Cache *acache ); |
| |
| /* */ |
| |
| #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 ) ) ) |
| |
| #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 ) ) ) |
| |
| /* */ |
| |
| FT_END_HEADER |
| |
| #endif /* __FTCMANAG_H__ */ |
| |
| |
| /* END */ |
