1 /***************************************************************************/
5 /* OpenType GPOS table validation (body). */
7 /* Copyright 2002, 2004, 2005, 2006, 2007, 2008 by */
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
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. */
16 /***************************************************************************/
24 /*************************************************************************/
26 /* The macro FT_COMPONENT is used in trace mode. It is an implicit */
27 /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */
28 /* messages during execution. */
31 #define FT_COMPONENT trace_otvgpos
35 otv_Anchor_validate( FT_Bytes table,
36 OTV_Validator valid );
39 otv_MarkArray_validate( FT_Bytes table,
40 OTV_Validator valid );
43 /*************************************************************************/
44 /*************************************************************************/
46 /***** UTILITY FUNCTIONS *****/
48 /*************************************************************************/
49 /*************************************************************************/
51 #define BaseArrayFunc otv_x_sxy
52 #define LigatureAttachFunc otv_x_sxy
53 #define Mark2ArrayFunc otv_x_sxy
55 /* uses valid->extra1 (counter) */
56 /* uses valid->extra2 (boolean to handle NULL anchor field) */
59 otv_x_sxy( FT_Bytes table,
60 OTV_Validator otvalid )
63 FT_UInt Count, count1, table_size;
70 Count = FT_NEXT_USHORT( p );
72 OTV_TRACE(( " (Count = %d)\n", Count ));
74 OTV_LIMIT_CHECK( Count * otvalid->extra1 * 2 );
76 table_size = Count * otvalid->extra1 * 2 + 2;
78 for ( ; Count > 0; Count-- )
79 for ( count1 = otvalid->extra1; count1 > 0; count1-- )
81 OTV_OPTIONAL_TABLE( anchor_offset );
84 OTV_OPTIONAL_OFFSET( anchor_offset );
86 if ( otvalid->extra2 )
88 OTV_SIZE_CHECK( anchor_offset );
90 otv_Anchor_validate( table + anchor_offset, otvalid );
93 otv_Anchor_validate( table + anchor_offset, otvalid );
100 #define MarkBasePosFormat1Func otv_u_O_O_u_O_O
101 #define MarkLigPosFormat1Func otv_u_O_O_u_O_O
102 #define MarkMarkPosFormat1Func otv_u_O_O_u_O_O
104 /* sets otvalid->extra1 (class count) */
107 otv_u_O_O_u_O_O( FT_Bytes table,
108 OTV_Validator otvalid )
111 FT_UInt Coverage1, Coverage2, ClassCount;
112 FT_UInt Array1, Array2;
113 OTV_Validate_Func func;
118 p += 2; /* skip PosFormat */
120 OTV_LIMIT_CHECK( 10 );
121 Coverage1 = FT_NEXT_USHORT( p );
122 Coverage2 = FT_NEXT_USHORT( p );
123 ClassCount = FT_NEXT_USHORT( p );
124 Array1 = FT_NEXT_USHORT( p );
125 Array2 = FT_NEXT_USHORT( p );
127 otv_Coverage_validate( table + Coverage1, otvalid, -1 );
128 otv_Coverage_validate( table + Coverage2, otvalid, -1 );
130 otv_MarkArray_validate( table + Array1, otvalid );
132 otvalid->nesting_level++;
133 func = otvalid->func[otvalid->nesting_level];
134 otvalid->extra1 = ClassCount;
136 func( table + Array2, otvalid );
138 otvalid->nesting_level--;
144 /*************************************************************************/
145 /*************************************************************************/
147 /***** VALUE RECORDS *****/
149 /*************************************************************************/
150 /*************************************************************************/
153 otv_value_length( FT_UInt format )
158 count = ( ( format & 0xAA ) >> 1 ) + ( format & 0x55 );
159 count = ( ( count & 0xCC ) >> 2 ) + ( count & 0x33 );
160 count = ( ( count & 0xF0 ) >> 4 ) + ( count & 0x0F );
166 /* uses otvalid->extra3 (pointer to base table) */
169 otv_ValueRecord_validate( FT_Bytes table,
171 OTV_Validator otvalid )
176 #ifdef FT_DEBUG_LEVEL_TRACE
181 OTV_NAME_ENTER( "ValueRecord" );
183 /* display `format' in dual representation */
184 for ( loop = 7; loop >= 0; loop-- )
187 res += ( format >> loop ) & 1;
190 OTV_TRACE(( " (format 0b%08lx)\n", res ));
193 if ( format >= 0x100 )
196 for ( count = 4; count > 0; count-- )
200 /* XPlacement, YPlacement, XAdvance, YAdvance */
201 OTV_LIMIT_CHECK( 2 );
208 for ( count = 4; count > 0; count-- )
212 FT_PtrDist table_size;
214 OTV_OPTIONAL_TABLE( device );
217 /* XPlaDevice, YPlaDevice, XAdvDevice, YAdvDevice */
218 OTV_LIMIT_CHECK( 2 );
219 OTV_OPTIONAL_OFFSET( device );
221 /* XXX: this value is usually too small, especially if the current */
222 /* ValueRecord is part of an array -- getting the correct table */
223 /* size is probably not worth the trouble */
225 table_size = p - otvalid->extra3;
227 OTV_SIZE_CHECK( device );
229 otv_Device_validate( otvalid->extra3 + device, otvalid );
238 /*************************************************************************/
239 /*************************************************************************/
241 /***** ANCHORS *****/
243 /*************************************************************************/
244 /*************************************************************************/
247 otv_Anchor_validate( FT_Bytes table,
248 OTV_Validator otvalid )
251 FT_UInt AnchorFormat;
254 OTV_NAME_ENTER( "Anchor");
256 OTV_LIMIT_CHECK( 6 );
257 AnchorFormat = FT_NEXT_USHORT( p );
259 OTV_TRACE(( " (format %d)\n", AnchorFormat ));
261 p += 4; /* skip XCoordinate and YCoordinate */
263 switch ( AnchorFormat )
269 OTV_LIMIT_CHECK( 2 ); /* AnchorPoint */
276 OTV_OPTIONAL_TABLE( XDeviceTable );
277 OTV_OPTIONAL_TABLE( YDeviceTable );
280 OTV_LIMIT_CHECK( 4 );
281 OTV_OPTIONAL_OFFSET( XDeviceTable );
282 OTV_OPTIONAL_OFFSET( YDeviceTable );
286 OTV_SIZE_CHECK( XDeviceTable );
288 otv_Device_validate( table + XDeviceTable, otvalid );
290 OTV_SIZE_CHECK( YDeviceTable );
292 otv_Device_validate( table + YDeviceTable, otvalid );
304 /*************************************************************************/
305 /*************************************************************************/
307 /***** MARK ARRAYS *****/
309 /*************************************************************************/
310 /*************************************************************************/
313 otv_MarkArray_validate( FT_Bytes table,
314 OTV_Validator otvalid )
320 OTV_NAME_ENTER( "MarkArray" );
322 OTV_LIMIT_CHECK( 2 );
323 MarkCount = FT_NEXT_USHORT( p );
325 OTV_TRACE(( " (MarkCount = %d)\n", MarkCount ));
327 OTV_LIMIT_CHECK( MarkCount * 4 );
330 for ( ; MarkCount > 0; MarkCount-- )
332 p += 2; /* skip Class */
334 otv_Anchor_validate( table + FT_NEXT_USHORT( p ), otvalid );
341 /*************************************************************************/
342 /*************************************************************************/
344 /***** GPOS LOOKUP TYPE 1 *****/
346 /*************************************************************************/
347 /*************************************************************************/
349 /* sets otvalid->extra3 (pointer to base table) */
352 otv_SinglePos_validate( FT_Bytes table,
353 OTV_Validator otvalid )
359 OTV_NAME_ENTER( "SinglePos" );
361 OTV_LIMIT_CHECK( 2 );
362 PosFormat = FT_NEXT_USHORT( p );
364 OTV_TRACE(( " (format %d)\n", PosFormat ));
366 otvalid->extra3 = table;
370 case 1: /* SinglePosFormat1 */
372 FT_UInt Coverage, ValueFormat;
375 OTV_LIMIT_CHECK( 4 );
376 Coverage = FT_NEXT_USHORT( p );
377 ValueFormat = FT_NEXT_USHORT( p );
379 otv_Coverage_validate( table + Coverage, otvalid, -1 );
380 otv_ValueRecord_validate( p, ValueFormat, otvalid ); /* Value */
384 case 2: /* SinglePosFormat2 */
386 FT_UInt Coverage, ValueFormat, ValueCount, len_value;
389 OTV_LIMIT_CHECK( 6 );
390 Coverage = FT_NEXT_USHORT( p );
391 ValueFormat = FT_NEXT_USHORT( p );
392 ValueCount = FT_NEXT_USHORT( p );
394 OTV_TRACE(( " (ValueCount = %d)\n", ValueCount ));
396 len_value = otv_value_length( ValueFormat );
398 otv_Coverage_validate( table + Coverage, otvalid, ValueCount );
400 OTV_LIMIT_CHECK( ValueCount * len_value );
403 for ( ; ValueCount > 0; ValueCount-- )
405 otv_ValueRecord_validate( p, ValueFormat, otvalid );
419 /*************************************************************************/
420 /*************************************************************************/
422 /***** GPOS LOOKUP TYPE 2 *****/
424 /*************************************************************************/
425 /*************************************************************************/
428 otv_PairSet_validate( FT_Bytes table,
431 OTV_Validator otvalid )
434 FT_UInt value_len1, value_len2, PairValueCount;
437 OTV_NAME_ENTER( "PairSet" );
439 OTV_LIMIT_CHECK( 2 );
440 PairValueCount = FT_NEXT_USHORT( p );
442 OTV_TRACE(( " (PairValueCount = %d)\n", PairValueCount ));
444 value_len1 = otv_value_length( format1 );
445 value_len2 = otv_value_length( format2 );
447 OTV_LIMIT_CHECK( PairValueCount * ( value_len1 + value_len2 + 2 ) );
449 /* PairValueRecord */
450 for ( ; PairValueCount > 0; PairValueCount-- )
452 p += 2; /* skip SecondGlyph */
455 otv_ValueRecord_validate( p, format1, otvalid ); /* Value1 */
459 otv_ValueRecord_validate( p, format2, otvalid ); /* Value2 */
467 /* sets otvalid->extra3 (pointer to base table) */
470 otv_PairPos_validate( FT_Bytes table,
471 OTV_Validator otvalid )
477 OTV_NAME_ENTER( "PairPos" );
479 OTV_LIMIT_CHECK( 2 );
480 PosFormat = FT_NEXT_USHORT( p );
482 OTV_TRACE(( " (format %d)\n", PosFormat ));
484 otvalid->extra3 = table;
488 case 1: /* PairPosFormat1 */
490 FT_UInt Coverage, ValueFormat1, ValueFormat2, PairSetCount;
493 OTV_LIMIT_CHECK( 8 );
494 Coverage = FT_NEXT_USHORT( p );
495 ValueFormat1 = FT_NEXT_USHORT( p );
496 ValueFormat2 = FT_NEXT_USHORT( p );
497 PairSetCount = FT_NEXT_USHORT( p );
499 OTV_TRACE(( " (PairSetCount = %d)\n", PairSetCount ));
501 otv_Coverage_validate( table + Coverage, otvalid, -1 );
503 OTV_LIMIT_CHECK( PairSetCount * 2 );
506 for ( ; PairSetCount > 0; PairSetCount-- )
507 otv_PairSet_validate( table + FT_NEXT_USHORT( p ),
508 ValueFormat1, ValueFormat2, otvalid );
512 case 2: /* PairPosFormat2 */
514 FT_UInt Coverage, ValueFormat1, ValueFormat2, ClassDef1, ClassDef2;
515 FT_UInt ClassCount1, ClassCount2, len_value1, len_value2, count;
518 OTV_LIMIT_CHECK( 14 );
519 Coverage = FT_NEXT_USHORT( p );
520 ValueFormat1 = FT_NEXT_USHORT( p );
521 ValueFormat2 = FT_NEXT_USHORT( p );
522 ClassDef1 = FT_NEXT_USHORT( p );
523 ClassDef2 = FT_NEXT_USHORT( p );
524 ClassCount1 = FT_NEXT_USHORT( p );
525 ClassCount2 = FT_NEXT_USHORT( p );
527 OTV_TRACE(( " (ClassCount1 = %d)\n", ClassCount1 ));
528 OTV_TRACE(( " (ClassCount2 = %d)\n", ClassCount2 ));
530 len_value1 = otv_value_length( ValueFormat1 );
531 len_value2 = otv_value_length( ValueFormat2 );
533 otv_Coverage_validate( table + Coverage, otvalid, -1 );
534 otv_ClassDef_validate( table + ClassDef1, otvalid );
535 otv_ClassDef_validate( table + ClassDef2, otvalid );
537 OTV_LIMIT_CHECK( ClassCount1 * ClassCount2 *
538 ( len_value1 + len_value2 ) );
541 for ( ; ClassCount1 > 0; ClassCount1-- )
544 for ( count = ClassCount2; count > 0; count-- )
548 otv_ValueRecord_validate( p, ValueFormat1, otvalid );
553 otv_ValueRecord_validate( p, ValueFormat2, otvalid );
568 /*************************************************************************/
569 /*************************************************************************/
571 /***** GPOS LOOKUP TYPE 3 *****/
573 /*************************************************************************/
574 /*************************************************************************/
577 otv_CursivePos_validate( FT_Bytes table,
578 OTV_Validator otvalid )
584 OTV_NAME_ENTER( "CursivePos" );
586 OTV_LIMIT_CHECK( 2 );
587 PosFormat = FT_NEXT_USHORT( p );
589 OTV_TRACE(( " (format %d)\n", PosFormat ));
593 case 1: /* CursivePosFormat1 */
596 FT_UInt Coverage, EntryExitCount;
598 OTV_OPTIONAL_TABLE( EntryAnchor );
599 OTV_OPTIONAL_TABLE( ExitAnchor );
602 OTV_LIMIT_CHECK( 4 );
603 Coverage = FT_NEXT_USHORT( p );
604 EntryExitCount = FT_NEXT_USHORT( p );
606 OTV_TRACE(( " (EntryExitCount = %d)\n", EntryExitCount ));
608 otv_Coverage_validate( table + Coverage, otvalid, EntryExitCount );
610 OTV_LIMIT_CHECK( EntryExitCount * 4 );
612 table_size = EntryExitCount * 4 + 4;
614 /* EntryExitRecord */
615 for ( ; EntryExitCount > 0; EntryExitCount-- )
617 OTV_OPTIONAL_OFFSET( EntryAnchor );
618 OTV_OPTIONAL_OFFSET( ExitAnchor );
620 OTV_SIZE_CHECK( EntryAnchor );
622 otv_Anchor_validate( table + EntryAnchor, otvalid );
624 OTV_SIZE_CHECK( ExitAnchor );
626 otv_Anchor_validate( table + ExitAnchor, otvalid );
639 /*************************************************************************/
640 /*************************************************************************/
642 /***** GPOS LOOKUP TYPE 4 *****/
644 /*************************************************************************/
645 /*************************************************************************/
647 /* UNDOCUMENTED (in OpenType 1.5): */
648 /* BaseRecord tables can contain NULL pointers. */
650 /* sets otvalid->extra2 (1) */
653 otv_MarkBasePos_validate( FT_Bytes table,
654 OTV_Validator otvalid )
660 OTV_NAME_ENTER( "MarkBasePos" );
662 OTV_LIMIT_CHECK( 2 );
663 PosFormat = FT_NEXT_USHORT( p );
665 OTV_TRACE(( " (format %d)\n", PosFormat ));
671 OTV_NEST2( MarkBasePosFormat1, BaseArray );
672 OTV_RUN( table, otvalid );
683 /*************************************************************************/
684 /*************************************************************************/
686 /***** GPOS LOOKUP TYPE 5 *****/
688 /*************************************************************************/
689 /*************************************************************************/
691 /* sets otvalid->extra2 (1) */
694 otv_MarkLigPos_validate( FT_Bytes table,
695 OTV_Validator otvalid )
701 OTV_NAME_ENTER( "MarkLigPos" );
703 OTV_LIMIT_CHECK( 2 );
704 PosFormat = FT_NEXT_USHORT( p );
706 OTV_TRACE(( " (format %d)\n", PosFormat ));
712 OTV_NEST3( MarkLigPosFormat1, LigatureArray, LigatureAttach );
713 OTV_RUN( table, otvalid );
724 /*************************************************************************/
725 /*************************************************************************/
727 /***** GPOS LOOKUP TYPE 6 *****/
729 /*************************************************************************/
730 /*************************************************************************/
732 /* sets otvalid->extra2 (0) */
735 otv_MarkMarkPos_validate( FT_Bytes table,
736 OTV_Validator otvalid )
742 OTV_NAME_ENTER( "MarkMarkPos" );
744 OTV_LIMIT_CHECK( 2 );
745 PosFormat = FT_NEXT_USHORT( p );
747 OTV_TRACE(( " (format %d)\n", PosFormat ));
753 OTV_NEST2( MarkMarkPosFormat1, Mark2Array );
754 OTV_RUN( table, otvalid );
765 /*************************************************************************/
766 /*************************************************************************/
768 /***** GPOS LOOKUP TYPE 7 *****/
770 /*************************************************************************/
771 /*************************************************************************/
773 /* sets otvalid->extra1 (lookup count) */
776 otv_ContextPos_validate( FT_Bytes table,
777 OTV_Validator otvalid )
783 OTV_NAME_ENTER( "ContextPos" );
785 OTV_LIMIT_CHECK( 2 );
786 PosFormat = FT_NEXT_USHORT( p );
788 OTV_TRACE(( " (format %d)\n", PosFormat ));
793 /* no need to check glyph indices/classes used as input for these */
794 /* context rules since even invalid glyph indices/classes return */
795 /* meaningful results */
797 otvalid->extra1 = otvalid->lookup_count;
798 OTV_NEST3( ContextPosFormat1, PosRuleSet, PosRule );
799 OTV_RUN( table, otvalid );
803 /* no need to check glyph indices/classes used as input for these */
804 /* context rules since even invalid glyph indices/classes return */
805 /* meaningful results */
807 OTV_NEST3( ContextPosFormat2, PosClassSet, PosClassRule );
808 OTV_RUN( table, otvalid );
812 OTV_NEST1( ContextPosFormat3 );
813 OTV_RUN( table, otvalid );
824 /*************************************************************************/
825 /*************************************************************************/
827 /***** GPOS LOOKUP TYPE 8 *****/
829 /*************************************************************************/
830 /*************************************************************************/
832 /* sets otvalid->extra1 (lookup count) */
835 otv_ChainContextPos_validate( FT_Bytes table,
836 OTV_Validator otvalid )
842 OTV_NAME_ENTER( "ChainContextPos" );
844 OTV_LIMIT_CHECK( 2 );
845 PosFormat = FT_NEXT_USHORT( p );
847 OTV_TRACE(( " (format %d)\n", PosFormat ));
852 /* no need to check glyph indices/classes used as input for these */
853 /* context rules since even invalid glyph indices/classes return */
854 /* meaningful results */
856 otvalid->extra1 = otvalid->lookup_count;
857 OTV_NEST3( ChainContextPosFormat1,
858 ChainPosRuleSet, ChainPosRule );
859 OTV_RUN( table, otvalid );
863 /* no need to check glyph indices/classes used as input for these */
864 /* context rules since even invalid glyph indices/classes return */
865 /* meaningful results */
867 OTV_NEST3( ChainContextPosFormat2,
868 ChainPosClassSet, ChainPosClassRule );
869 OTV_RUN( table, otvalid );
873 OTV_NEST1( ChainContextPosFormat3 );
874 OTV_RUN( table, otvalid );
885 /*************************************************************************/
886 /*************************************************************************/
888 /***** GPOS LOOKUP TYPE 9 *****/
890 /*************************************************************************/
891 /*************************************************************************/
893 /* uses otvalid->type_funcs */
896 otv_ExtensionPos_validate( FT_Bytes table,
897 OTV_Validator otvalid )
903 OTV_NAME_ENTER( "ExtensionPos" );
905 OTV_LIMIT_CHECK( 2 );
906 PosFormat = FT_NEXT_USHORT( p );
908 OTV_TRACE(( " (format %d)\n", PosFormat ));
912 case 1: /* ExtensionPosFormat1 */
914 FT_UInt ExtensionLookupType;
915 FT_ULong ExtensionOffset;
916 OTV_Validate_Func validate;
919 OTV_LIMIT_CHECK( 6 );
920 ExtensionLookupType = FT_NEXT_USHORT( p );
921 ExtensionOffset = FT_NEXT_ULONG( p );
923 if ( ExtensionLookupType == 0 || ExtensionLookupType >= 9 )
926 validate = otvalid->type_funcs[ExtensionLookupType - 1];
927 validate( table + ExtensionOffset, otvalid );
939 static const OTV_Validate_Func otv_gpos_validate_funcs[9] =
941 otv_SinglePos_validate,
942 otv_PairPos_validate,
943 otv_CursivePos_validate,
944 otv_MarkBasePos_validate,
945 otv_MarkLigPos_validate,
946 otv_MarkMarkPos_validate,
947 otv_ContextPos_validate,
948 otv_ChainContextPos_validate,
949 otv_ExtensionPos_validate
953 /* sets otvalid->type_count */
954 /* sets otvalid->type_funcs */
957 otv_GPOS_subtable_validate( FT_Bytes table,
958 OTV_Validator otvalid )
960 otvalid->type_count = 9;
961 otvalid->type_funcs = (OTV_Validate_Func*)otv_gpos_validate_funcs;
963 otv_Lookup_validate( table, otvalid );
967 /*************************************************************************/
968 /*************************************************************************/
970 /***** GPOS TABLE *****/
972 /*************************************************************************/
973 /*************************************************************************/
975 /* sets otvalid->glyph_count */
978 otv_GPOS_validate( FT_Bytes table,
980 FT_Validator ftvalid )
982 OTV_ValidatorRec validrec;
983 OTV_Validator otvalid = &validrec;
985 FT_UInt ScriptList, FeatureList, LookupList;
988 otvalid->root = ftvalid;
990 FT_TRACE3(( "validating GPOS table\n" ));
993 OTV_LIMIT_CHECK( 10 );
995 if ( FT_NEXT_ULONG( p ) != 0x10000UL ) /* Version */
998 ScriptList = FT_NEXT_USHORT( p );
999 FeatureList = FT_NEXT_USHORT( p );
1000 LookupList = FT_NEXT_USHORT( p );
1002 otvalid->type_count = 9;
1003 otvalid->type_funcs = (OTV_Validate_Func*)otv_gpos_validate_funcs;
1004 otvalid->glyph_count = glyph_count;
1006 otv_LookupList_validate( table + LookupList,
1008 otv_FeatureList_validate( table + FeatureList, table + LookupList,
1010 otv_ScriptList_validate( table + ScriptList, table + FeatureList,
1013 FT_TRACE4(( "\n" ));