Visualization Library 2.0.0-b5

A lightweight C++ OpenGL middleware for 2D/3D graphics

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ftvalid.h
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1 /***************************************************************************/
2 /* */
3 /* ftvalid.h */
4 /* */
5 /* FreeType validation support (specification). */
6 /* */
7 /* Copyright 2004 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 #ifndef __FTVALID_H__
20 #define __FTVALID_H__
21 
22 #include <ft2build.h>
23 #include FT_CONFIG_STANDARD_LIBRARY_H /* for ft_setjmp and ft_longjmp */
24 
25 
27 
28 
29  /*************************************************************************/
30  /*************************************************************************/
31  /*************************************************************************/
32  /**** ****/
33  /**** ****/
34  /**** V A L I D A T I O N ****/
35  /**** ****/
36  /**** ****/
37  /*************************************************************************/
38  /*************************************************************************/
39  /*************************************************************************/
40 
41  /* handle to a validation object */
42  typedef struct FT_ValidatorRec_ volatile* FT_Validator;
43 
44 
45  /*************************************************************************/
46  /* */
47  /* There are three distinct validation levels defined here: */
48  /* */
49  /* FT_VALIDATE_DEFAULT :: */
50  /* A table that passes this validation level can be used reliably by */
51  /* FreeType. It generally means that all offsets have been checked to */
52  /* prevent out-of-bound reads, that array counts are correct, etc. */
53  /* */
54  /* FT_VALIDATE_TIGHT :: */
55  /* A table that passes this validation level can be used reliably and */
56  /* doesn't contain invalid data. For example, a charmap table that */
57  /* returns invalid glyph indices will not pass, even though it can */
58  /* be used with FreeType in default mode (the library will simply */
59  /* return an error later when trying to load the glyph). */
60  /* */
61  /* It also checks that fields which must be a multiple of 2, 4, or 8, */
62  /* don't have incorrect values, etc. */
63  /* */
64  /* FT_VALIDATE_PARANOID :: */
65  /* Only for font debugging. Checks that a table follows the */
66  /* specification by 100%. Very few fonts will be able to pass this */
67  /* level anyway but it can be useful for certain tools like font */
68  /* editors/converters. */
69  /* */
70  typedef enum FT_ValidationLevel_
71  {
75 
77 
78 
79  /* validator structure */
80  typedef struct FT_ValidatorRec_
81  {
82  const FT_Byte* base; /* address of table in memory */
83  const FT_Byte* limit; /* `base' + sizeof(table) in memory */
84  FT_ValidationLevel level; /* validation level */
85  FT_Error error; /* error returned. 0 means success */
86 
87  ft_jmp_buf jump_buffer; /* used for exception handling */
88 
90 
91 
92 #define FT_VALIDATOR( x ) ((FT_Validator)( x ))
93 
94 
95  FT_BASE( void )
96  ft_validator_init( FT_Validator valid,
97  const FT_Byte* base,
98  const FT_Byte* limit,
100 
101  /* Do not use this. It's broken and will cause your validator to crash */
102  /* if you run it on an invalid font. */
103  FT_BASE( FT_Int )
104  ft_validator_run( FT_Validator valid );
105 
106  /* Sets the error field in a validator, then calls `longjmp' to return */
107  /* to high-level caller. Using `setjmp/longjmp' avoids many stupid */
108  /* error checks within the validation routines. */
109  /* */
110  FT_BASE( void )
111  ft_validator_error( FT_Validator valid,
112  FT_Error error );
113 
114 
115  /* Calls ft_validate_error. Assumes that the `valid' local variable */
116  /* holds a pointer to the current validator object. */
117  /* */
118  /* Use preprocessor prescan to pass FT_ERR_PREFIX. */
119  /* */
120 #define FT_INVALID( _prefix, _error ) FT_INVALID_( _prefix, _error )
121 #define FT_INVALID_( _prefix, _error ) \
122  ft_validator_error( valid, _prefix ## _error )
123 
124  /* called when a broken table is detected */
125 #define FT_INVALID_TOO_SHORT \
126  FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
127 
128  /* called when an invalid offset is detected */
129 #define FT_INVALID_OFFSET \
130  FT_INVALID( FT_ERR_PREFIX, Invalid_Offset )
131 
132  /* called when an invalid format/value is detected */
133 #define FT_INVALID_FORMAT \
134  FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
135 
136  /* called when an invalid glyph index is detected */
137 #define FT_INVALID_GLYPH_ID \
138  FT_INVALID( FT_ERR_PREFIX, Invalid_Glyph_Index )
139 
140  /* called when an invalid field value is detected */
141 #define FT_INVALID_DATA \
142  FT_INVALID( FT_ERR_PREFIX, Invalid_Table )
143 
144 
146 
147 #endif /* __FTVALID_H__ */
148 
149 
150 /* END */
#define ft_jmp_buf
Definition: ftstdlib.h:157
int FT_Error
Definition: fttypes.h:296
struct FT_ValidatorRec_ FT_ValidatorRec
#define FT_END_HEADER
Definition: ftheader.h:54
signed int FT_Int
Definition: fttypes.h:216
enum FT_ValidationLevel_ FT_ValidationLevel
ft_jmp_buf jump_buffer
Definition: ftvalid.h:87
ft_validator_run(FT_Validator valid)
Definition: ftobjs.c:95
FT_Error error
Definition: ftvalid.h:85
unsigned char FT_Byte
Definition: fttypes.h:150
#define FT_BEGIN_HEADER
Definition: ftheader.h:36
#define FT_BASE(x)
Definition: ftconfig.h:247
GLint level
FT_ValidationLevel_
Definition: ftvalid.h:70
typedefFT_BEGIN_HEADER struct FT_ValidatorRec_ volatile * FT_Validator
Definition: ftvalid.h:42
ft_validator_error(FT_Validator valid, FT_Error error)
Definition: ftobjs.c:105
const FT_Byte * limit
Definition: ftvalid.h:83
FT_ValidationLevel level
Definition: ftvalid.h:84
ft_validator_init(FT_Validator valid, const FT_Byte *base, const FT_Byte *limit, FT_ValidationLevel level)
Definition: ftobjs.c:82
const FT_Byte * base
Definition: ftvalid.h:82
GLint limit