ReactOS  0.4.14-dev-323-g6fe6a88
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 
110  } FTC_ManagerRec;
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  */
141  FT_LOCAL( FT_UInt )
143  FT_UInt count );
144 
145 
146  /* this must be used internally for the moment */
147  FT_LOCAL( FT_Error )
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 */
int FT_Error
Definition: fttypes.h:300
FT_UInt num_nodes
Definition: ftcmanag.h:99
FTC_Manager_FlushN(FTC_Manager manager, FT_UInt count)
Definition: ftcmanag.c:632
FTC_MruListRec faces
Definition: ftcmanag.h:104
#define FT_END_HEADER
Definition: ftheader.h:54
GLuint GLuint GLsizei count
Definition: gl.h:1545
FT_Offset max_weight
Definition: ftcmanag.h:97
struct FTC_ManagerRec_ FTC_ManagerRec
FT_Offset cur_weight
Definition: ftcmanag.h:98
FT_Library library
Definition: ftcmanag.h:93
FT_Memory memory
Definition: ftcmanag.h:94
#define FT_BEGIN_HEADER
Definition: ftheader.h:36
#define FT_LOCAL(x)
Definition: ftconfig.h:387
FT_Error(* FTC_Face_Requester)(FTC_FaceID face_id, FT_Library library, FT_Pointer req_data, FT_Face *aface)
Definition: ftcache.h:210
typedefFT_BEGIN_HEADER struct FT_MemoryRec_ * FT_Memory
Definition: ftsystem.h:66
FTC_Manager_RegisterCache(FTC_Manager manager, FTC_CacheClass clazz, FTC_Cache *acache)
Definition: ftcmanag.c:580
FT_Pointer request_data
Definition: ftcmanag.h:107
FTC_Node nodes_list
Definition: ftcmanag.h:96
FTC_MruListRec sizes
Definition: ftcmanag.h:105
unsigned int FT_UInt
Definition: fttypes.h:231
#define FTC_MAX_CACHES
Definition: ftcmanag.h:88
FTC_Manager_Compress(FTC_Manager manager)
Definition: ftcmanag.c:538
FT_UInt num_caches
Definition: ftcmanag.h:102
FTC_Cache caches[FTC_MAX_CACHES]
Definition: ftcmanag.h:101
size_t FT_Offset
Definition: fttypes.h:324
FTC_Face_Requester request_face
Definition: ftcmanag.h:108