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1 /****************************************************************************
2  *
3  * ttbdf.c
4  *
5  *   TrueType and OpenType embedded BDF properties (body).
6  *
7  * Copyright (C) 2005-2019 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 <ft2build.h>
20 #include FT_INTERNAL_DEBUG_H
21 #include FT_INTERNAL_STREAM_H
22 #include FT_TRUETYPE_TAGS_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  ttbdf
38 
39 
40   FT_LOCAL_DEF( void )
tt_face_free_bdf_props(TT_Face face)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 )
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
tt_face_load_bdf_props(TT_Face face,FT_Stream stream)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 )
tt_face_find_bdf_prop(TT_Face face,const char * property_name,BDF_PropertyRec * aprop)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 || !property_name )
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 
181       if ( _ppem == size->metrics.y_ppem )
182       {
183         count = _count;
184         goto FoundStrike;
185       }
186 
187       strike += 10 * _count;
188     }
189     goto Exit;
190 
191   FoundStrike:
192     p = strike;
193     for ( ; count > 0; count-- )
194     {
195       FT_UInt  type = FT_PEEK_USHORT( p + 4 );
196 
197 
198       if ( ( type & 0x10 ) != 0 )
199       {
200         FT_UInt32  name_offset = FT_PEEK_ULONG( p     );
201         FT_UInt32  value       = FT_PEEK_ULONG( p + 6 );
202 
203         /* be a bit paranoid for invalid entries here */
204         if ( name_offset < bdf->strings_size                    &&
205              property_len < bdf->strings_size - name_offset     &&
206              ft_strncmp( property_name,
207                          (const char*)bdf->strings + name_offset,
208                          bdf->strings_size - name_offset ) == 0 )
209         {
210           switch ( type & 0x0F )
211           {
212           case 0x00:  /* string */
213           case 0x01:  /* atoms */
214             /* check that the content is really 0-terminated */
215             if ( value < bdf->strings_size &&
216                  ft_memchr( bdf->strings + value, 0, bdf->strings_size ) )
217             {
218               aprop->type   = BDF_PROPERTY_TYPE_ATOM;
219               aprop->u.atom = (const char*)bdf->strings + value;
220               error         = FT_Err_Ok;
221               goto Exit;
222             }
223             break;
224 
225           case 0x02:
226             aprop->type      = BDF_PROPERTY_TYPE_INTEGER;
227             aprop->u.integer = (FT_Int32)value;
228             error            = FT_Err_Ok;
229             goto Exit;
230 
231           case 0x03:
232             aprop->type       = BDF_PROPERTY_TYPE_CARDINAL;
233             aprop->u.cardinal = value;
234             error             = FT_Err_Ok;
235             goto Exit;
236 
237           default:
238             ;
239           }
240         }
241       }
242       p += 10;
243     }
244 
245   Exit:
246     return error;
247   }
248 
249 #else /* !TT_CONFIG_OPTION_BDF */
250 
251   /* ANSI C doesn't like empty source files */
252   typedef int  _tt_bdf_dummy;
253 
254 #endif /* !TT_CONFIG_OPTION_BDF */
255 
256 
257 /* END */
258