| /**************************************************************************** |
| * |
| * ftcmanag.h |
| * |
| * FreeType Cache Manager (specification). |
| * |
| * Copyright (C) 2000-2021 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 <freetype/ftcache.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 */ |