ttbdf.c revision ee451cb395940862dad63c85adfe8f2fd55e864c 
1/***************************************************************************/
2/*                                                                         */
3/*  ttbdf.c                                                                */
4/*                                                                         */
5/*    TrueType and OpenType embedded BDF properties (body).                */
6/*                                                                         */
7/*  Copyright 2005, 2006, 2010, 2013 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#include "../../include/ft2build.h"
20#include "../../include/freetype/internal/ftdebug.h"
21#include "../../include/freetype/internal/ftstream.h"
22#include "../../include/freetype/tttags.h"
23#include "ttbdf.h"
24
25#include "sferrors.h"
26
27
28#ifdef TT_CONFIG_OPTION_BDF
29
30  /*************************************************************************/
31  /*                                                                       */
32  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
33  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
34  /* messages during execution.                                            */
35  /*                                                                       */
36#undef  FT_COMPONENT
37#define FT_COMPONENT  trace_ttbdf
38
39
40  FT_LOCAL_DEF( void )
41  tt_face_free_bdf_props( TT_Face  face )
42  {
43    TT_BDF  bdf = &face->bdf;
44
45
46    if ( bdf->loaded )
47    {
48      FT_Stream  stream = FT_FACE(face)->stream;
49
50
51      if ( bdf->table != NULL )
52        FT_FRAME_RELEASE( bdf->table );
53
54      bdf->table_end    = NULL;
55      bdf->strings      = NULL;
56      bdf->strings_size = 0;
57    }
58  }
59
60
61  static FT_Error
62  tt_face_load_bdf_props( TT_Face    face,
63                          FT_Stream  stream )
64  {
65    TT_BDF    bdf = &face->bdf;
66    FT_ULong  length;
67    FT_Error  error;
68
69
70    FT_ZERO( bdf );
71
72    error = tt_face_goto_table( face, TTAG_BDF, stream, &length );
73    if ( error                                  ||
74         length < 8                             ||
75         FT_FRAME_EXTRACT( length, bdf->table ) )
76    {
77      error = FT_THROW( Invalid_Table );
78      goto Exit;
79    }
80
81    bdf->table_end = bdf->table + length;
82
83    {
84      FT_Byte*   p           = bdf->table;
85      FT_UInt    version     = FT_NEXT_USHORT( p );
86      FT_UInt    num_strikes = FT_NEXT_USHORT( p );
87      FT_ULong   strings     = FT_NEXT_ULONG ( p );
88      FT_UInt    count;
89      FT_Byte*   strike;
90
91
92      if ( version != 0x0001                 ||
93           strings < 8                       ||
94           ( strings - 8 ) / 4 < num_strikes ||
95           strings + 1 > length              )
96      {
97        goto BadTable;
98      }
99
100      bdf->num_strikes  = num_strikes;
101      bdf->strings      = bdf->table + strings;
102      bdf->strings_size = length - strings;
103
104      count  = bdf->num_strikes;
105      p      = bdf->table + 8;
106      strike = p + count * 4;
107
108
109      for ( ; count > 0; count-- )
110      {
111        FT_UInt  num_items = FT_PEEK_USHORT( p + 2 );
112
113        /*
114         *  We don't need to check the value sets themselves, since this
115         *  is done later.
116         */
117        strike += 10 * num_items;
118
119        p += 4;
120      }
121
122      if ( strike > bdf->strings )
123        goto BadTable;
124    }
125
126    bdf->loaded = 1;
127
128  Exit:
129    return error;
130
131  BadTable:
132    FT_FRAME_RELEASE( bdf->table );
133    FT_ZERO( bdf );
134    error = FT_THROW( Invalid_Table );
135    goto Exit;
136  }
137
138
139  FT_LOCAL_DEF( FT_Error )
140  tt_face_find_bdf_prop( TT_Face           face,
141                         const char*       property_name,
142                         BDF_PropertyRec  *aprop )
143  {
144    TT_BDF     bdf   = &face->bdf;
145    FT_Size    size  = FT_FACE(face)->size;
146    FT_Error   error = FT_Err_Ok;
147    FT_Byte*   p;
148    FT_UInt    count;
149    FT_Byte*   strike;
150    FT_Offset  property_len;
151
152
153    aprop->type = BDF_PROPERTY_TYPE_NONE;
154
155    if ( bdf->loaded == 0 )
156    {
157      error = tt_face_load_bdf_props( face, FT_FACE( face )->stream );
158      if ( error )
159        goto Exit;
160    }
161
162    count  = bdf->num_strikes;
163    p      = bdf->table + 8;
164    strike = p + 4 * count;
165
166    error = FT_ERR( Invalid_Argument );
167
168    if ( size == NULL || property_name == NULL )
169      goto Exit;
170
171    property_len = ft_strlen( property_name );
172    if ( property_len == 0 )
173      goto Exit;
174
175    for ( ; count > 0; count-- )
176    {
177      FT_UInt  _ppem  = FT_NEXT_USHORT( p );
178      FT_UInt  _count = FT_NEXT_USHORT( p );
179
180      if ( _ppem == size->metrics.y_ppem )
181      {
182        count = _count;
183        goto FoundStrike;
184      }
185
186      strike += 10 * _count;
187    }
188    goto Exit;
189
190  FoundStrike:
191    p = strike;
192    for ( ; count > 0; count-- )
193    {
194      FT_UInt  type = FT_PEEK_USHORT( p + 4 );
195
196      if ( ( type & 0x10 ) != 0 )
197      {
198        FT_UInt32  name_offset = FT_PEEK_ULONG( p     );
199        FT_UInt32  value       = FT_PEEK_ULONG( p + 6 );
200
201        /* be a bit paranoid for invalid entries here */
202        if ( name_offset < bdf->strings_size                    &&
203             property_len < bdf->strings_size - name_offset     &&
204             ft_strncmp( property_name,
205                         (const char*)bdf->strings + name_offset,
206                         bdf->strings_size - name_offset ) == 0 )
207        {
208          switch ( type & 0x0F )
209          {
210          case 0x00:  /* string */
211          case 0x01:  /* atoms */
212            /* check that the content is really 0-terminated */
213            if ( value < bdf->strings_size &&
214                 ft_memchr( bdf->strings + value, 0, bdf->strings_size ) )
215            {
216              aprop->type   = BDF_PROPERTY_TYPE_ATOM;
217              aprop->u.atom = (const char*)bdf->strings + value;
218              error         = FT_Err_Ok;
219              goto Exit;
220            }
221            break;
222
223          case 0x02:
224            aprop->type      = BDF_PROPERTY_TYPE_INTEGER;
225            aprop->u.integer = (FT_Int32)value;
226            error            = FT_Err_Ok;
227            goto Exit;
228
229          case 0x03:
230            aprop->type       = BDF_PROPERTY_TYPE_CARDINAL;
231            aprop->u.cardinal = value;
232            error             = FT_Err_Ok;
233            goto Exit;
234
235          default:
236            ;
237          }
238        }
239      }
240      p += 10;
241    }
242
243  Exit:
244    return error;
245  }
246
247#endif /* TT_CONFIG_OPTION_BDF */
248
249
250/* END */
251