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Diffstat (limited to 'modules/freetype2/src/cache/ftcmanag.h')
| -rw-r--r-- | modules/freetype2/src/cache/ftcmanag.h | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/modules/freetype2/src/cache/ftcmanag.h b/modules/freetype2/src/cache/ftcmanag.h new file mode 100644 index 0000000000..5b30929c9a --- /dev/null +++ b/modules/freetype2/src/cache/ftcmanag.h @@ -0,0 +1,175 @@ +/**************************************************************************** + * + * ftcmanag.h + * + * FreeType Cache Manager (specification). + * + * Copyright (C) 2000-2023 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 */ |