ReactOS 0.4.15-dev-8131-g4988de4
ftcmanag.h
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1/***************************************************************************/
2/* */
3/* ftcmanag.h */
4/* */
5/* FreeType Cache Manager (specification). */
6/* */
7/* Copyright 2000-2018 by */
8/* David Turner, Robert Wilhelm, and Werner Lemberg. */
9/* */
10/* This file is part of the FreeType project, and may only be used, */
11/* modified, and distributed under the terms of the FreeType project */
12/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
13/* this file you indicate that you have read the license and */
14/* understand and accept it fully. */
15/* */
16/***************************************************************************/
17
18
19 /*************************************************************************/
20 /* */
21 /* A cache manager is in charge of the following: */
22 /* */
23 /* - Maintain a mapping between generic FTC_FaceIDs and live FT_Face */
24 /* objects. The mapping itself is performed through a user-provided */
25 /* callback. However, the manager maintains a small cache of FT_Face */
26 /* and FT_Size objects in order to speed up things considerably. */
27 /* */
28 /* - Manage one or more cache objects. Each cache is in charge of */
29 /* holding a varying number of `cache nodes'. Each cache node */
30 /* represents a minimal amount of individually accessible cached */
31 /* data. For example, a cache node can be an FT_Glyph image */
32 /* containing a vector outline, or some glyph metrics, or anything */
33 /* else. */
34 /* */
35 /* Each cache node has a certain size in bytes that is added to the */
36 /* total amount of `cache memory' within the manager. */
37 /* */
38 /* All cache nodes are located in a global LRU list, where the oldest */
39 /* node is at the tail of the list. */
40 /* */
41 /* Each node belongs to a single cache, and includes a reference */
42 /* count to avoid destroying it (due to caching). */
43 /* */
44 /*************************************************************************/
45
46
47 /*************************************************************************/
48 /*************************************************************************/
49 /*************************************************************************/
50 /*************************************************************************/
51 /*************************************************************************/
52 /********* *********/
53 /********* WARNING, THIS IS BETA CODE. *********/
54 /********* *********/
55 /*************************************************************************/
56 /*************************************************************************/
57 /*************************************************************************/
58 /*************************************************************************/
59 /*************************************************************************/
60
61
62#ifndef FTCMANAG_H_
63#define FTCMANAG_H_
64
65
66#include <ft2build.h>
67#include FT_CACHE_H
68#include "ftcmru.h"
69#include "ftccache.h"
70
71
73
74
75 /*************************************************************************/
76 /* */
77 /* <Section> */
78 /* cache_subsystem */
79 /* */
80 /*************************************************************************/
81
82
83#define FTC_MAX_FACES_DEFAULT 2
84#define FTC_MAX_SIZES_DEFAULT 4
85#define FTC_MAX_BYTES_DEFAULT 200000L /* ~200kByte by default */
86
87 /* maximum number of caches registered in a single manager */
88#define FTC_MAX_CACHES 16
89
90
91 typedef struct FTC_ManagerRec_
92 {
95
100
103
106
109
111
112
113 /*************************************************************************/
114 /* */
115 /* <Function> */
116 /* FTC_Manager_Compress */
117 /* */
118 /* <Description> */
119 /* This function is used to check the state of the cache manager if */
120 /* its `num_bytes' field is greater than its `max_bytes' field. It */
121 /* will flush as many old cache nodes as possible (ignoring cache */
122 /* nodes with a non-zero reference count). */
123 /* */
124 /* <InOut> */
125 /* manager :: A handle to the cache manager. */
126 /* */
127 /* <Note> */
128 /* Client applications should not call this function directly. It is */
129 /* normally invoked by specific cache implementations. */
130 /* */
131 /* The reason this function is exported is to allow client-specific */
132 /* cache classes. */
133 /* */
134 FT_LOCAL( void )
136
137
138 /* try to flush `count' old nodes from the cache; return the number
139 * of really flushed nodes
140 */
143 FT_UInt count );
144
145
146 /* this must be used internally for the moment */
149 FTC_CacheClass clazz,
150 FTC_Cache *acache );
151
152 /* */
153
154#define FTC_SCALER_COMPARE( a, b ) \
155 ( (a)->face_id == (b)->face_id && \
156 (a)->width == (b)->width && \
157 (a)->height == (b)->height && \
158 ((a)->pixel != 0) == ((b)->pixel != 0) && \
159 ( (a)->pixel || \
160 ( (a)->x_res == (b)->x_res && \
161 (a)->y_res == (b)->y_res ) ) )
162
163#define FTC_SCALER_HASH( q ) \
164 ( FTC_FACE_ID_HASH( (q)->face_id ) + \
165 (q)->width + (q)->height*7 + \
166 ( (q)->pixel ? 0 : ( (q)->x_res*33 ^ (q)->y_res*61 ) ) )
167
168 /* */
169
171
172#endif /* FTCMANAG_H_ */
173
174
175/* END */
FT_Error(* FTC_Face_Requester)(FTC_FaceID face_id, FT_Library library, FT_Pointer req_data, FT_Face *aface)
Definition: ftcache.h:210
FTC_Manager_RegisterCache(FTC_Manager manager, FTC_CacheClass clazz, FTC_Cache *acache)
Definition: ftcmanag.c:580
struct FTC_ManagerRec_ FTC_ManagerRec
FTC_Manager_Compress(FTC_Manager manager)
Definition: ftcmanag.c:538
FTC_Manager_FlushN(FTC_Manager manager, FT_UInt count)
Definition: ftcmanag.c:632
#define FTC_MAX_CACHES
Definition: ftcmanag.h:88
#define FT_LOCAL(x)
Definition: ftconfig.h:387
#define FT_END_HEADER
Definition: ftheader.h:54
#define FT_BEGIN_HEADER
Definition: ftheader.h:36
typedefFT_BEGIN_HEADER struct FT_MemoryRec_ * FT_Memory
Definition: ftsystem.h:66
int FT_Error
Definition: fttypes.h:300
unsigned int FT_UInt
Definition: fttypes.h:231
size_t FT_Offset
Definition: fttypes.h:324
GLuint GLuint GLsizei count
Definition: gl.h:1545
FT_UInt num_caches
Definition: ftcmanag.h:102
FT_Pointer request_data
Definition: ftcmanag.h:107
FTC_Cache caches[FTC_MAX_CACHES]
Definition: ftcmanag.h:101
FT_Offset cur_weight
Definition: ftcmanag.h:98
FTC_MruListRec faces
Definition: ftcmanag.h:104
FT_Memory memory
Definition: ftcmanag.h:94
FTC_Face_Requester request_face
Definition: ftcmanag.h:108
FT_Offset max_weight
Definition: ftcmanag.h:97
FTC_Node nodes_list
Definition: ftcmanag.h:96
FT_Library library
Definition: ftcmanag.h:93
FTC_MruListRec sizes
Definition: ftcmanag.h:105
FT_UInt num_nodes
Definition: ftcmanag.h:99