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/src/freetype/src/gxvalid/gxvmort.c

https://bitbucket.org/cabalistic/ogredeps/
C | 296 lines | 196 code | 62 blank | 38 comment | 18 complexity | 69011460b18cd064a3b0be7590053c54 MD5 | raw file
  1/***************************************************************************/
  2/*                                                                         */
  3/*  gxvmort.c                                                              */
  4/*                                                                         */
  5/*    TrueTypeGX/AAT mort table validation (body).                         */
  6/*                                                                         */
  7/*  Copyright 2005 by suzuki toshiya, Masatake YAMATO, Red Hat K.K.,       */
  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/* gxvalid is derived from both gxlayout module and otvalid module.        */
 21/* Development of gxlayout is supported by the Information-technology      */
 22/* Promotion Agency(IPA), Japan.                                           */
 23/*                                                                         */
 24/***************************************************************************/
 25
 26
 27#include "gxvmort.h"
 28#include "gxvfeat.h"
 29
 30
 31  /*************************************************************************/
 32  /*                                                                       */
 33  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
 34  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
 35  /* messages during execution.                                            */
 36  /*                                                                       */
 37#undef  FT_COMPONENT
 38#define FT_COMPONENT  trace_gxvmort
 39
 40
 41  static void
 42  gxv_mort_feature_validate( GXV_mort_feature  f,
 43                             GXV_Validator     valid )
 44  {
 45    if ( f->featureType >= gxv_feat_registry_length )
 46    {
 47      GXV_TRACE(( "featureType %d is out of registered range, "
 48                  "setting %d is unchecked\n",
 49                  f->featureType, f->featureSetting ));
 50      GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
 51    }
 52    else if ( !gxv_feat_registry[f->featureType].existence )
 53    {
 54      GXV_TRACE(( "featureType %d is within registered area "
 55                  "but undefined, setting %d is unchecked\n",
 56                  f->featureType, f->featureSetting ));
 57      GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
 58    }
 59    else
 60    {
 61      FT_Byte  nSettings_max;
 62
 63
 64      /* nSettings in gxvfeat.c is halved for exclusive on/off settings */
 65      nSettings_max = gxv_feat_registry[f->featureType].nSettings;
 66      if ( gxv_feat_registry[f->featureType].exclusive )
 67        nSettings_max = (FT_Byte)( 2 * nSettings_max );
 68
 69      GXV_TRACE(( "featureType %d is registered", f->featureType ));
 70      GXV_TRACE(( "setting %d", f->featureSetting ));
 71
 72      if ( f->featureSetting > nSettings_max )
 73      {
 74        GXV_TRACE(( "out of defined range %d", nSettings_max ));
 75        GXV_SET_ERR_IF_PARANOID( FT_INVALID_DATA );
 76      }
 77      GXV_TRACE(( "\n" ));
 78    }
 79
 80    /* TODO: enableFlags must be unique value in specified chain?  */
 81  }
 82
 83
 84  /*
 85   * nFeatureFlags is typed to FT_ULong to accept that in
 86   * mort (typed FT_UShort) and morx (typed FT_ULong).
 87   */
 88  FT_LOCAL_DEF( void )
 89  gxv_mort_featurearray_validate( FT_Bytes       table,
 90                                  FT_Bytes       limit,
 91                                  FT_ULong       nFeatureFlags,
 92                                  GXV_Validator  valid )
 93  {
 94    FT_Bytes  p = table;
 95    FT_ULong  i;
 96
 97    GXV_mort_featureRec  f = GXV_MORT_FEATURE_OFF;
 98
 99
100    GXV_NAME_ENTER( "mort feature list" );
101    for ( i = 0; i < nFeatureFlags; i++ )
102    {
103      GXV_LIMIT_CHECK( 2 + 2 + 4 + 4 );
104      f.featureType    = FT_NEXT_USHORT( p );
105      f.featureSetting = FT_NEXT_USHORT( p );
106      f.enableFlags    = FT_NEXT_ULONG( p );
107      f.disableFlags   = FT_NEXT_ULONG( p );
108
109      gxv_mort_feature_validate( &f, valid );
110    }
111
112    if ( !IS_GXV_MORT_FEATURE_OFF( f ) )
113      FT_INVALID_DATA;
114
115    valid->subtable_length = p - table;
116    GXV_EXIT;
117  }
118
119
120  FT_LOCAL_DEF( void )
121  gxv_mort_coverage_validate( FT_UShort      coverage,
122                              GXV_Validator  valid )
123  {
124    FT_UNUSED( valid );
125
126    if ( coverage & 0x8000U )
127      GXV_TRACE(( " this subtable is for vertical text only\n" ));
128    else
129      GXV_TRACE(( " this subtable is for horizontal text only\n" ));
130
131    if ( coverage & 0x4000 )
132      GXV_TRACE(( " this subtable is applied to glyph array "
133                  "in descending order\n" ));
134    else
135      GXV_TRACE(( " this subtable is applied to glyph array "
136                  "in ascending order\n" ));
137
138    if ( coverage & 0x2000 )
139      GXV_TRACE(( " this subtable is forcibly applied to "
140                  "vertical/horizontal text\n" ));
141
142    if ( coverage & 0x1FF8 )
143      GXV_TRACE(( " coverage has non-zero bits in reserved area\n" ));
144  }
145
146
147  static void
148  gxv_mort_subtables_validate( FT_Bytes       table,
149                               FT_Bytes       limit,
150                               FT_UShort      nSubtables,
151                               GXV_Validator  valid )
152  {
153    FT_Bytes  p = table;
154
155    GXV_Validate_Func fmt_funcs_table[] =
156    {
157      gxv_mort_subtable_type0_validate, /* 0 */
158      gxv_mort_subtable_type1_validate, /* 1 */
159      gxv_mort_subtable_type2_validate, /* 2 */
160      NULL,                             /* 3 */
161      gxv_mort_subtable_type4_validate, /* 4 */
162      gxv_mort_subtable_type5_validate, /* 5 */
163
164    };
165
166    GXV_Validate_Func  func;
167    FT_UShort          i;
168
169
170    GXV_NAME_ENTER( "subtables in a chain" );
171
172    for ( i = 0; i < nSubtables; i++ )
173    {
174      FT_UShort  length;
175      FT_UShort  coverage;
176#ifdef GXV_LOAD_UNUSED_VARS
177      FT_ULong   subFeatureFlags;
178#endif
179      FT_UInt    type;
180      FT_UInt    rest;
181
182
183      GXV_LIMIT_CHECK( 2 + 2 + 4 );
184      length          = FT_NEXT_USHORT( p );
185      coverage        = FT_NEXT_USHORT( p );
186#ifdef GXV_LOAD_UNUSED_VARS
187      subFeatureFlags = FT_NEXT_ULONG( p );
188#else
189      p += 4;
190#endif
191
192      GXV_TRACE(( "validating chain subtable %d/%d (%d bytes)\n",
193                  i + 1, nSubtables, length ));
194      type = coverage & 0x0007;
195      rest = length - ( 2 + 2 + 4 );
196
197      GXV_LIMIT_CHECK( rest );
198      gxv_mort_coverage_validate( coverage, valid );
199
200      if ( type > 5 )
201        FT_INVALID_FORMAT;
202
203      func = fmt_funcs_table[type];
204      if ( func == NULL )
205        GXV_TRACE(( "morx type %d is reserved\n", type ));
206
207      func( p, p + rest, valid );
208
209      p += rest;
210      /* TODO: validate subFeatureFlags */
211    }
212
213    valid->subtable_length = p - table;
214
215    GXV_EXIT;
216  }
217
218
219  static void
220  gxv_mort_chain_validate( FT_Bytes       table,
221                           FT_Bytes       limit,
222                           GXV_Validator  valid )
223  {
224    FT_Bytes   p = table;
225#ifdef GXV_LOAD_UNUSED_VARS
226    FT_ULong   defaultFlags;
227#endif
228    FT_ULong   chainLength;
229    FT_UShort  nFeatureFlags;
230    FT_UShort  nSubtables;
231
232
233    GXV_NAME_ENTER( "mort chain header" );
234
235    GXV_LIMIT_CHECK( 4 + 4 + 2 + 2 );
236#ifdef GXV_LOAD_UNUSED_VARS
237    defaultFlags  = FT_NEXT_ULONG( p );
238#else
239    p += 4;
240#endif
241    chainLength   = FT_NEXT_ULONG( p );
242    nFeatureFlags = FT_NEXT_USHORT( p );
243    nSubtables    = FT_NEXT_USHORT( p );
244
245    gxv_mort_featurearray_validate( p, table + chainLength,
246                                    nFeatureFlags, valid );
247    p += valid->subtable_length;
248    gxv_mort_subtables_validate( p, table + chainLength, nSubtables, valid );
249    valid->subtable_length = chainLength;
250
251    /* TODO: validate defaultFlags */
252    GXV_EXIT;
253  }
254
255
256  FT_LOCAL_DEF( void )
257  gxv_mort_validate( FT_Bytes      table,
258                     FT_Face       face,
259                     FT_Validator  ftvalid )
260  {
261    GXV_ValidatorRec  validrec;
262    GXV_Validator     valid = &validrec;
263    FT_Bytes          p     = table;
264    FT_Bytes          limit = 0;
265    FT_ULong          version;
266    FT_ULong          nChains;
267    FT_ULong          i;
268
269
270    valid->root = ftvalid;
271    valid->face = face;
272    limit       = valid->root->limit;
273
274    FT_TRACE3(( "validating `mort' table\n" ));
275    GXV_INIT;
276
277    GXV_LIMIT_CHECK( 4 + 4 );
278    version = FT_NEXT_ULONG( p );
279    nChains = FT_NEXT_ULONG( p );
280
281    if (version != 0x00010000UL)
282      FT_INVALID_FORMAT;
283
284    for ( i = 0; i < nChains; i++ )
285    {
286      GXV_TRACE(( "validating chain %d/%d\n", i + 1, nChains ));
287      GXV_32BIT_ALIGNMENT_VALIDATE( p - table );
288      gxv_mort_chain_validate( p, limit, valid );
289      p += valid->subtable_length;
290    }
291
292    FT_TRACE4(( "\n" ));
293  }
294
295
296/* END */