xref: /aosp_15_r20/external/freetype/src/psaux/t1decode.c (revision 63949dbd25bcc50c4e1178497ff9e9574d44fc5a)
1 /****************************************************************************
2  *
3  * t1decode.c
4  *
5  *   PostScript Type 1 decoding routines (body).
6  *
7  * Copyright (C) 2000-2023 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 <freetype/internal/ftcalc.h>
20 #include <freetype/internal/ftdebug.h>
21 #include <freetype/internal/pshints.h>
22 #include <freetype/internal/fthash.h>
23 #include <freetype/ftoutln.h>
24 
25 #include "t1decode.h"
26 #include "psobjs.h"
27 
28 #include "psauxerr.h"
29 
30 
31 /* ensure proper sign extension */
32 #define Fix2Int( f )   ( (FT_Int) (FT_Short)( (f) >> 16 ) )
33 #define Fix2UInt( f )  ( (FT_UInt)(FT_Short)( (f) >> 16 ) )
34 
35 
36   /**************************************************************************
37    *
38    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
39    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
40    * messages during execution.
41    */
42 #undef  FT_COMPONENT
43 #define FT_COMPONENT  t1decode
44 
45 
46   typedef enum  T1_Operator_
47   {
48     op_none = 0,
49     op_endchar,
50     op_hsbw,
51     op_seac,
52     op_sbw,
53     op_closepath,
54     op_hlineto,
55     op_hmoveto,
56     op_hvcurveto,
57     op_rlineto,
58     op_rmoveto,
59     op_rrcurveto,
60     op_vhcurveto,
61     op_vlineto,
62     op_vmoveto,
63     op_dotsection,
64     op_hstem,
65     op_hstem3,
66     op_vstem,
67     op_vstem3,
68     op_div,
69     op_callothersubr,
70     op_callsubr,
71     op_pop,
72     op_return,
73     op_setcurrentpoint,
74     op_unknown15,
75 
76     op_max    /* never remove this one */
77 
78   } T1_Operator;
79 
80 
81   static
82   const FT_Int  t1_args_count[op_max] =
83   {
84     0, /* none */
85     0, /* endchar */
86     2, /* hsbw */
87     5, /* seac */
88     4, /* sbw */
89     0, /* closepath */
90     1, /* hlineto */
91     1, /* hmoveto */
92     4, /* hvcurveto */
93     2, /* rlineto */
94     2, /* rmoveto */
95     6, /* rrcurveto */
96     4, /* vhcurveto */
97     1, /* vlineto */
98     1, /* vmoveto */
99     0, /* dotsection */
100     2, /* hstem */
101     6, /* hstem3 */
102     2, /* vstem */
103     6, /* vstem3 */
104     2, /* div */
105    -1, /* callothersubr */
106     1, /* callsubr */
107     0, /* pop */
108     0, /* return */
109     2, /* setcurrentpoint */
110     2  /* opcode 15 (undocumented and obsolete) */
111   };
112 
113 
114   /**************************************************************************
115    *
116    * @Function:
117    *   t1_lookup_glyph_by_stdcharcode_ps
118    *
119    * @Description:
120    *   Looks up a given glyph by its StandardEncoding charcode.  Used to
121    *   implement the SEAC Type 1 operator in the Adobe engine
122    *
123    * @Input:
124    *   face ::
125    *     The current face object.
126    *
127    *   charcode ::
128    *     The character code to look for.
129    *
130    * @Return:
131    *   A glyph index in the font face.  Returns -1 if the corresponding
132    *   glyph wasn't found.
133    */
134   FT_LOCAL_DEF( FT_Int )
t1_lookup_glyph_by_stdcharcode_ps(PS_Decoder * decoder,FT_Int charcode)135   t1_lookup_glyph_by_stdcharcode_ps( PS_Decoder*  decoder,
136                                      FT_Int       charcode )
137   {
138     FT_UInt             n;
139     const FT_String*    glyph_name;
140     FT_Service_PsCMaps  psnames = decoder->psnames;
141 
142 
143     /* check range of standard char code */
144     if ( charcode < 0 || charcode > 255 )
145       return -1;
146 
147     glyph_name = psnames->adobe_std_strings(
148                    psnames->adobe_std_encoding[charcode]);
149 
150     for ( n = 0; n < decoder->num_glyphs; n++ )
151     {
152       FT_String*  name = (FT_String*)decoder->glyph_names[n];
153 
154 
155       if ( name                               &&
156            name[0] == glyph_name[0]           &&
157            ft_strcmp( name, glyph_name ) == 0 )
158         return (FT_Int)n;
159     }
160 
161     return -1;
162   }
163 
164 
165 #ifdef T1_CONFIG_OPTION_OLD_ENGINE
166 
167   /**************************************************************************
168    *
169    * @Function:
170    *   t1_lookup_glyph_by_stdcharcode
171    *
172    * @Description:
173    *   Looks up a given glyph by its StandardEncoding charcode.  Used to
174    *   implement the SEAC Type 1 operator.
175    *
176    * @Input:
177    *   face ::
178    *     The current face object.
179    *
180    *   charcode ::
181    *     The character code to look for.
182    *
183    * @Return:
184    *   A glyph index in the font face.  Returns -1 if the corresponding
185    *   glyph wasn't found.
186    */
187   static FT_Int
t1_lookup_glyph_by_stdcharcode(T1_Decoder decoder,FT_Int charcode)188   t1_lookup_glyph_by_stdcharcode( T1_Decoder  decoder,
189                                   FT_Int      charcode )
190   {
191     FT_UInt             n;
192     const FT_String*    glyph_name;
193     FT_Service_PsCMaps  psnames = decoder->psnames;
194 
195 
196     /* check range of standard char code */
197     if ( charcode < 0 || charcode > 255 )
198       return -1;
199 
200     glyph_name = psnames->adobe_std_strings(
201                    psnames->adobe_std_encoding[charcode]);
202 
203     for ( n = 0; n < decoder->num_glyphs; n++ )
204     {
205       FT_String*  name = (FT_String*)decoder->glyph_names[n];
206 
207 
208       if ( name                               &&
209            name[0] == glyph_name[0]           &&
210            ft_strcmp( name, glyph_name ) == 0 )
211         return (FT_Int)n;
212     }
213 
214     return -1;
215   }
216 
217 
218   /* parse a single Type 1 glyph */
219   FT_LOCAL_DEF( FT_Error )
t1_decoder_parse_glyph(T1_Decoder decoder,FT_UInt glyph)220   t1_decoder_parse_glyph( T1_Decoder  decoder,
221                           FT_UInt     glyph )
222   {
223     return decoder->parse_callback( decoder, glyph );
224   }
225 
226 
227   /**************************************************************************
228    *
229    * @Function:
230    *   t1operator_seac
231    *
232    * @Description:
233    *   Implements the `seac' Type 1 operator for a Type 1 decoder.
234    *
235    * @Input:
236    *   decoder ::
237    *     The current CID decoder.
238    *
239    *   asb ::
240    *     The accent's side bearing.
241    *
242    *   adx ::
243    *     The horizontal offset of the accent.
244    *
245    *   ady ::
246    *     The vertical offset of the accent.
247    *
248    *   bchar ::
249    *     The base character's StandardEncoding charcode.
250    *
251    *   achar ::
252    *     The accent character's StandardEncoding charcode.
253    *
254    * @Return:
255    *   FreeType error code.  0 means success.
256    */
257   static FT_Error
t1operator_seac(T1_Decoder decoder,FT_Pos asb,FT_Pos adx,FT_Pos ady,FT_Int bchar,FT_Int achar)258   t1operator_seac( T1_Decoder  decoder,
259                    FT_Pos      asb,
260                    FT_Pos      adx,
261                    FT_Pos      ady,
262                    FT_Int      bchar,
263                    FT_Int      achar )
264   {
265     FT_Error     error;
266     FT_Int       bchar_index, achar_index;
267 #if 0
268     FT_Int       n_base_points;
269     FT_Outline*  base = decoder->builder.base;
270 #endif
271     FT_Vector    left_bearing, advance;
272 
273 #ifdef FT_CONFIG_OPTION_INCREMENTAL
274     T1_Face      face  = (T1_Face)decoder->builder.face;
275 #endif
276 
277 
278     if ( decoder->seac )
279     {
280       FT_ERROR(( "t1operator_seac: invalid nested seac\n" ));
281       return FT_THROW( Syntax_Error );
282     }
283 
284     if ( decoder->builder.metrics_only )
285     {
286       FT_ERROR(( "t1operator_seac: unexpected seac\n" ));
287       return FT_THROW( Syntax_Error );
288     }
289 
290     /* seac weirdness */
291     adx += decoder->builder.left_bearing.x;
292 
293     /* `glyph_names' is set to 0 for CID fonts which do not */
294     /* include an encoding.  How can we deal with these?    */
295 #ifdef FT_CONFIG_OPTION_INCREMENTAL
296     if ( decoder->glyph_names == 0                   &&
297          !face->root.internal->incremental_interface )
298 #else
299     if ( decoder->glyph_names == 0 )
300 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
301     {
302       FT_ERROR(( "t1operator_seac:"
303                  " glyph names table not available in this font\n" ));
304       return FT_THROW( Syntax_Error );
305     }
306 
307 #ifdef FT_CONFIG_OPTION_INCREMENTAL
308     if ( face->root.internal->incremental_interface )
309     {
310       /* the caller must handle the font encoding also */
311       bchar_index = bchar;
312       achar_index = achar;
313     }
314     else
315 #endif
316     {
317       bchar_index = t1_lookup_glyph_by_stdcharcode( decoder, bchar );
318       achar_index = t1_lookup_glyph_by_stdcharcode( decoder, achar );
319     }
320 
321     if ( bchar_index < 0 || achar_index < 0 )
322     {
323       FT_ERROR(( "t1operator_seac:"
324                  " invalid seac character code arguments\n" ));
325       return FT_THROW( Syntax_Error );
326     }
327 
328     /* if we are trying to load a composite glyph, do not load the */
329     /* accent character and return the array of subglyphs.         */
330     if ( decoder->builder.no_recurse )
331     {
332       FT_GlyphSlot    glyph  = (FT_GlyphSlot)decoder->builder.glyph;
333       FT_GlyphLoader  loader = glyph->internal->loader;
334       FT_SubGlyph     subg;
335 
336 
337       /* reallocate subglyph array if necessary */
338       error = FT_GlyphLoader_CheckSubGlyphs( loader, 2 );
339       if ( error )
340         goto Exit;
341 
342       subg = loader->current.subglyphs;
343 
344       /* subglyph 0 = base character */
345       subg->index = bchar_index;
346       subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES |
347                     FT_SUBGLYPH_FLAG_USE_MY_METRICS;
348       subg->arg1  = 0;
349       subg->arg2  = 0;
350       subg++;
351 
352       /* subglyph 1 = accent character */
353       subg->index = achar_index;
354       subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES;
355       subg->arg1  = (FT_Int)FIXED_TO_INT( adx - asb );
356       subg->arg2  = (FT_Int)FIXED_TO_INT( ady );
357 
358       /* set up remaining glyph fields */
359       glyph->num_subglyphs = 2;
360       glyph->subglyphs     = loader->base.subglyphs;
361       glyph->format        = FT_GLYPH_FORMAT_COMPOSITE;
362 
363       loader->current.num_subglyphs = 2;
364       goto Exit;
365     }
366 
367     /* First load `bchar' in builder */
368     /* now load the unscaled outline */
369 
370     FT_GlyphLoader_Prepare( decoder->builder.loader );  /* prepare loader */
371 
372     /* save the left bearing and width of the SEAC   */
373     /* glyph as they will be erased by the next load */
374 
375     left_bearing = decoder->builder.left_bearing;
376     advance      = decoder->builder.advance;
377 
378     /* the seac operator must not be nested */
379     decoder->seac = TRUE;
380     error = t1_decoder_parse_glyph( decoder, (FT_UInt)bchar_index );
381     decoder->seac = FALSE;
382     if ( error )
383       goto Exit;
384 
385     /* If the SEAC glyph doesn't have a (H)SBW of its */
386     /* own use the values from the base glyph.        */
387 
388     if ( decoder->builder.parse_state != T1_Parse_Have_Width )
389     {
390       left_bearing = decoder->builder.left_bearing;
391       advance      = decoder->builder.advance;
392     }
393 
394     decoder->builder.left_bearing.x = 0;
395     decoder->builder.left_bearing.y = 0;
396 
397     decoder->builder.pos_x = adx - asb;
398     decoder->builder.pos_y = ady;
399 
400     /* Now load `achar' on top of */
401     /* the base outline           */
402 
403     /* the seac operator must not be nested */
404     decoder->seac = TRUE;
405     error = t1_decoder_parse_glyph( decoder, (FT_UInt)achar_index );
406     decoder->seac = FALSE;
407     if ( error )
408       goto Exit;
409 
410     /* restore the left side bearing and advance width   */
411     /* of the SEAC glyph or base character (saved above) */
412 
413     decoder->builder.left_bearing = left_bearing;
414     decoder->builder.advance      = advance;
415 
416     decoder->builder.pos_x = 0;
417     decoder->builder.pos_y = 0;
418 
419   Exit:
420     return error;
421   }
422 
423 
424   /**************************************************************************
425    *
426    * @Function:
427    *   t1_decoder_parse_charstrings
428    *
429    * @Description:
430    *   Parses a given Type 1 charstrings program.
431    *
432    * @Input:
433    *   decoder ::
434    *     The current Type 1 decoder.
435    *
436    *   charstring_base ::
437    *     The base address of the charstring stream.
438    *
439    *   charstring_len ::
440    *     The length in bytes of the charstring stream.
441    *
442    * @Return:
443    *   FreeType error code.  0 means success.
444    */
445   FT_LOCAL_DEF( FT_Error )
t1_decoder_parse_charstrings(T1_Decoder decoder,FT_Byte * charstring_base,FT_UInt charstring_len)446   t1_decoder_parse_charstrings( T1_Decoder  decoder,
447                                 FT_Byte*    charstring_base,
448                                 FT_UInt     charstring_len )
449   {
450     FT_Error         error;
451     T1_Decoder_Zone  zone;
452     FT_Byte*         ip;
453     FT_Byte*         limit;
454     T1_Builder       builder = &decoder->builder;
455     FT_Pos           x, y, orig_x, orig_y;
456     FT_Int           known_othersubr_result_cnt   = 0;
457     FT_Int           unknown_othersubr_result_cnt = 0;
458     FT_Bool          large_int;
459     FT_Fixed         seed;
460 
461     T1_Hints_Funcs   hinter;
462 
463 #ifdef FT_DEBUG_LEVEL_TRACE
464     FT_Bool          bol = TRUE;
465 #endif
466 
467 
468     /* compute random seed from stack address of parameter */
469     seed = (FT_Fixed)( ( (FT_Offset)(char*)&seed            ^
470                          (FT_Offset)(char*)&decoder         ^
471                          (FT_Offset)(char*)&charstring_base ) &
472                          FT_ULONG_MAX                         );
473     seed = ( seed ^ ( seed >> 10 ) ^ ( seed >> 20 ) ) & 0xFFFFL;
474     if ( seed == 0 )
475       seed = 0x7384;
476 
477     /* First of all, initialize the decoder */
478     decoder->top  = decoder->stack;
479     decoder->zone = decoder->zones;
480     zone          = decoder->zones;
481 
482     builder->parse_state = T1_Parse_Start;
483 
484     hinter = (T1_Hints_Funcs)builder->hints_funcs;
485 
486     /* a font that reads BuildCharArray without setting */
487     /* its values first is buggy, but ...               */
488     FT_ASSERT( ( decoder->len_buildchar == 0 ) ==
489                ( decoder->buildchar == NULL )  );
490 
491     if ( decoder->buildchar && decoder->len_buildchar > 0 )
492       FT_ARRAY_ZERO( decoder->buildchar, decoder->len_buildchar );
493 
494     zone->base           = charstring_base;
495     limit = zone->limit  = charstring_base + charstring_len;
496     ip    = zone->cursor = zone->base;
497 
498     error = FT_Err_Ok;
499 
500     x = orig_x = builder->pos_x;
501     y = orig_y = builder->pos_y;
502 
503     /* begin hints recording session, if any */
504     if ( hinter )
505       hinter->open( hinter->hints );
506 
507     large_int = FALSE;
508 
509     /* now, execute loop */
510     while ( ip < limit )
511     {
512       FT_Long*     top   = decoder->top;
513       T1_Operator  op    = op_none;
514       FT_Int32     value = 0;
515 
516 
517       FT_ASSERT( known_othersubr_result_cnt == 0   ||
518                  unknown_othersubr_result_cnt == 0 );
519 
520 #ifdef FT_DEBUG_LEVEL_TRACE
521       if ( bol )
522       {
523         FT_TRACE5(( " (%td)", decoder->top - decoder->stack ));
524         bol = FALSE;
525       }
526 #endif
527 
528       /**********************************************************************
529        *
530        * Decode operator or operand
531        *
532        */
533 
534       /* first of all, decompress operator or value */
535       switch ( *ip++ )
536       {
537       case 1:
538         op = op_hstem;
539         break;
540 
541       case 3:
542         op = op_vstem;
543         break;
544       case 4:
545         op = op_vmoveto;
546         break;
547       case 5:
548         op = op_rlineto;
549         break;
550       case 6:
551         op = op_hlineto;
552         break;
553       case 7:
554         op = op_vlineto;
555         break;
556       case 8:
557         op = op_rrcurveto;
558         break;
559       case 9:
560         op = op_closepath;
561         break;
562       case 10:
563         op = op_callsubr;
564         break;
565       case 11:
566         op = op_return;
567         break;
568 
569       case 13:
570         op = op_hsbw;
571         break;
572       case 14:
573         op = op_endchar;
574         break;
575 
576       case 15:          /* undocumented, obsolete operator */
577         op = op_unknown15;
578         break;
579 
580       case 21:
581         op = op_rmoveto;
582         break;
583       case 22:
584         op = op_hmoveto;
585         break;
586 
587       case 30:
588         op = op_vhcurveto;
589         break;
590       case 31:
591         op = op_hvcurveto;
592         break;
593 
594       case 12:
595         if ( ip >= limit )
596         {
597           FT_ERROR(( "t1_decoder_parse_charstrings:"
598                      " invalid escape (12+EOF)\n" ));
599           goto Syntax_Error;
600         }
601 
602         switch ( *ip++ )
603         {
604         case 0:
605           op = op_dotsection;
606           break;
607         case 1:
608           op = op_vstem3;
609           break;
610         case 2:
611           op = op_hstem3;
612           break;
613         case 6:
614           op = op_seac;
615           break;
616         case 7:
617           op = op_sbw;
618           break;
619         case 12:
620           op = op_div;
621           break;
622         case 16:
623           op = op_callothersubr;
624           break;
625         case 17:
626           op = op_pop;
627           break;
628         case 33:
629           op = op_setcurrentpoint;
630           break;
631 
632         default:
633           FT_ERROR(( "t1_decoder_parse_charstrings:"
634                      " invalid escape (12+%d)\n",
635                      ip[-1] ));
636           goto Syntax_Error;
637         }
638         break;
639 
640       case 255:    /* four bytes integer */
641         if ( ip + 4 > limit )
642         {
643           FT_ERROR(( "t1_decoder_parse_charstrings:"
644                      " unexpected EOF in integer\n" ));
645           goto Syntax_Error;
646         }
647 
648         value = (FT_Int32)( ( (FT_UInt32)ip[0] << 24 ) |
649                             ( (FT_UInt32)ip[1] << 16 ) |
650                             ( (FT_UInt32)ip[2] << 8  ) |
651                               (FT_UInt32)ip[3]         );
652         ip += 4;
653 
654         /* According to the specification, values > 32000 or < -32000 must */
655         /* be followed by a `div' operator to make the result be in the    */
656         /* range [-32000;32000].  We expect that the second argument of    */
657         /* `div' is not a large number.  Additionally, we don't handle     */
658         /* stuff like `<large1> <large2> <num> div <num> div' or           */
659         /* <large1> <large2> <num> div div'.  This is probably not allowed */
660         /* anyway.                                                         */
661         if ( value > 32000 || value < -32000 )
662         {
663           if ( large_int )
664             FT_ERROR(( "t1_decoder_parse_charstrings:"
665                        " no `div' after large integer\n" ));
666           else
667             large_int = TRUE;
668         }
669         else
670         {
671           if ( !large_int )
672             value = (FT_Int32)( (FT_UInt32)value << 16 );
673         }
674 
675         break;
676 
677       default:
678         if ( ip[-1] >= 32 )
679         {
680           if ( ip[-1] < 247 )
681             value = (FT_Int32)ip[-1] - 139;
682           else
683           {
684             if ( ++ip > limit )
685             {
686               FT_ERROR(( "t1_decoder_parse_charstrings:"
687                          " unexpected EOF in integer\n" ));
688               goto Syntax_Error;
689             }
690 
691             if ( ip[-2] < 251 )
692               value =    ( ( ip[-2] - 247 ) * 256 ) + ip[-1] + 108;
693             else
694               value = -( ( ( ip[-2] - 251 ) * 256 ) + ip[-1] + 108 );
695           }
696 
697           if ( !large_int )
698             value = (FT_Int32)( (FT_UInt32)value << 16 );
699         }
700         else
701         {
702           FT_ERROR(( "t1_decoder_parse_charstrings:"
703                      " invalid byte (%d)\n", ip[-1] ));
704           goto Syntax_Error;
705         }
706       }
707 
708       if ( unknown_othersubr_result_cnt > 0 )
709       {
710         switch ( op )
711         {
712         case op_callsubr:
713         case op_return:
714         case op_none:
715         case op_pop:
716           break;
717 
718         default:
719           /* all operands have been transferred by previous pops */
720           unknown_othersubr_result_cnt = 0;
721           break;
722         }
723       }
724 
725       if ( large_int && !( op == op_none || op == op_div ) )
726       {
727         FT_ERROR(( "t1_decoder_parse_charstrings:"
728                    " no `div' after large integer\n" ));
729 
730         large_int = FALSE;
731       }
732 
733       /**********************************************************************
734        *
735        * Push value on stack, or process operator
736        *
737        */
738       if ( op == op_none )
739       {
740         if ( top - decoder->stack >= T1_MAX_CHARSTRINGS_OPERANDS )
741         {
742           FT_ERROR(( "t1_decoder_parse_charstrings: stack overflow\n" ));
743           goto Syntax_Error;
744         }
745 
746 #ifdef FT_DEBUG_LEVEL_TRACE
747         if ( large_int )
748           FT_TRACE4(( " %d", value ));
749         else
750           FT_TRACE4(( " %d", value / 65536 ));
751 #endif
752 
753         *top++       = value;
754         decoder->top = top;
755       }
756       else if ( op == op_callothersubr )  /* callothersubr */
757       {
758         FT_Int  subr_no;
759         FT_Int  arg_cnt;
760 
761 
762 #ifdef FT_DEBUG_LEVEL_TRACE
763         FT_TRACE4(( " callothersubr\n" ));
764         bol = TRUE;
765 #endif
766 
767         if ( top - decoder->stack < 2 )
768           goto Stack_Underflow;
769 
770         top -= 2;
771 
772         subr_no = Fix2Int( top[1] );
773         arg_cnt = Fix2Int( top[0] );
774 
775         /************************************************************
776          *
777          * remove all operands to callothersubr from the stack
778          *
779          * for handled othersubrs, where we know the number of
780          * arguments, we increase the stack by the value of
781          * known_othersubr_result_cnt
782          *
783          * for unhandled othersubrs the following pops adjust the
784          * stack pointer as necessary
785          */
786 
787         if ( arg_cnt > top - decoder->stack )
788           goto Stack_Underflow;
789 
790         top -= arg_cnt;
791 
792         known_othersubr_result_cnt   = 0;
793         unknown_othersubr_result_cnt = 0;
794 
795         /* XXX TODO: The checks to `arg_count == <whatever>'       */
796         /* might not be correct; an othersubr expects a certain    */
797         /* number of operands on the PostScript stack (as opposed  */
798         /* to the T1 stack) but it doesn't have to put them there  */
799         /* by itself; previous othersubrs might have left the      */
800         /* operands there if they were not followed by an          */
801         /* appropriate number of pops                              */
802         /*                                                         */
803         /* On the other hand, Adobe Reader 7.0.8 for Linux doesn't */
804         /* accept a font that contains charstrings like            */
805         /*                                                         */
806         /*     100 200 2 20 callothersubr                          */
807         /*     300 1 20 callothersubr pop                          */
808         /*                                                         */
809         /* Perhaps this is the reason why BuildCharArray exists.   */
810 
811         switch ( subr_no )
812         {
813         case 0:                     /* end flex feature */
814           if ( arg_cnt != 3 )
815             goto Unexpected_OtherSubr;
816 
817           if ( !decoder->flex_state           ||
818                decoder->num_flex_vectors != 7 )
819           {
820             FT_ERROR(( "t1_decoder_parse_charstrings:"
821                        " unexpected flex end\n" ));
822             goto Syntax_Error;
823           }
824 
825           /* the two `results' are popped by the following setcurrentpoint */
826           top[0] = x;
827           top[1] = y;
828           known_othersubr_result_cnt = 2;
829           break;
830 
831         case 1:                     /* start flex feature */
832           if ( arg_cnt != 0 )
833             goto Unexpected_OtherSubr;
834 
835           if ( FT_SET_ERROR( t1_builder_start_point( builder, x, y ) ) ||
836                FT_SET_ERROR( t1_builder_check_points( builder, 6 ) )   )
837             goto Fail;
838 
839           decoder->flex_state        = 1;
840           decoder->num_flex_vectors  = 0;
841           break;
842 
843         case 2:                     /* add flex vectors */
844           {
845             FT_Int  idx;
846 
847 
848             if ( arg_cnt != 0 )
849               goto Unexpected_OtherSubr;
850 
851             if ( !decoder->flex_state )
852             {
853               FT_ERROR(( "t1_decoder_parse_charstrings:"
854                          " missing flex start\n" ));
855               goto Syntax_Error;
856             }
857 
858             /* note that we should not add a point for index 0; */
859             /* this will move our current position to the flex  */
860             /* point without adding any point to the outline    */
861             idx = decoder->num_flex_vectors++;
862             if ( idx > 0 && idx < 7 )
863             {
864               /* in malformed fonts it is possible to have other */
865               /* opcodes in the middle of a flex (which don't    */
866               /* increase `num_flex_vectors'); we thus have to   */
867               /* check whether we can add a point                */
868               if ( FT_SET_ERROR( t1_builder_check_points( builder, 1 ) ) )
869                 goto Syntax_Error;
870 
871               t1_builder_add_point( builder,
872                                     x,
873                                     y,
874                                     (FT_Byte)( idx == 3 || idx == 6 ) );
875             }
876           }
877           break;
878 
879         case 3:                     /* change hints */
880           if ( arg_cnt != 1 )
881             goto Unexpected_OtherSubr;
882 
883           known_othersubr_result_cnt = 1;
884 
885           if ( hinter )
886             hinter->reset( hinter->hints,
887                            (FT_UInt)builder->current->n_points );
888           break;
889 
890         case 12:
891         case 13:
892           /* counter control hints, clear stack */
893           top = decoder->stack;
894           break;
895 
896         case 14:
897         case 15:
898         case 16:
899         case 17:
900         case 18:                    /* multiple masters */
901           {
902             PS_Blend  blend = decoder->blend;
903             FT_UInt   num_points, nn, mm;
904             FT_Long*  delta;
905             FT_Long*  values;
906 
907 
908             if ( !blend )
909             {
910               FT_ERROR(( "t1_decoder_parse_charstrings:"
911                          " unexpected multiple masters operator\n" ));
912               goto Syntax_Error;
913             }
914 
915             num_points = (FT_UInt)subr_no - 13 + ( subr_no == 18 );
916             if ( arg_cnt != (FT_Int)( num_points * blend->num_designs ) )
917             {
918               FT_ERROR(( "t1_decoder_parse_charstrings:"
919                          " incorrect number of multiple masters arguments\n" ));
920               goto Syntax_Error;
921             }
922 
923             /* We want to compute                                    */
924             /*                                                       */
925             /*   a0*w0 + a1*w1 + ... + ak*wk                         */
926             /*                                                       */
927             /* but we only have a0, a1-a0, a2-a0, ..., ak-a0.        */
928             /*                                                       */
929             /* However, given that w0 + w1 + ... + wk == 1, we can   */
930             /* rewrite it easily as                                  */
931             /*                                                       */
932             /*   a0 + (a1-a0)*w1 + (a2-a0)*w2 + ... + (ak-a0)*wk     */
933             /*                                                       */
934             /* where k == num_designs-1.                             */
935             /*                                                       */
936             /* I guess that's why it's written in this `compact'     */
937             /* form.                                                 */
938             /*                                                       */
939             delta  = top + num_points;
940             values = top;
941             for ( nn = 0; nn < num_points; nn++ )
942             {
943               FT_Long  tmp = values[0];
944 
945 
946               for ( mm = 1; mm < blend->num_designs; mm++ )
947                 tmp = ADD_LONG( tmp,
948                                 FT_MulFix( *delta++,
949                                            blend->weight_vector[mm] ) );
950 
951               *values++ = tmp;
952             }
953 
954             known_othersubr_result_cnt = (FT_Int)num_points;
955             break;
956           }
957 
958         case 19:
959           /* <idx> 1 19 callothersubr                             */
960           /* => replace elements starting from index cvi( <idx> ) */
961           /*    of BuildCharArray with WeightVector               */
962           {
963             FT_Int    idx;
964             PS_Blend  blend = decoder->blend;
965 
966 
967             if ( arg_cnt != 1 || !blend )
968               goto Unexpected_OtherSubr;
969 
970             idx = Fix2Int( top[0] );
971 
972             if ( idx < 0                                                    ||
973                  (FT_UInt)idx + blend->num_designs > decoder->len_buildchar )
974               goto Unexpected_OtherSubr;
975 
976             ft_memcpy( &decoder->buildchar[idx],
977                        blend->weight_vector,
978                        blend->num_designs *
979                          sizeof ( blend->weight_vector[0] ) );
980           }
981           break;
982 
983         case 20:
984           /* <arg1> <arg2> 2 20 callothersubr pop   */
985           /* ==> push <arg1> + <arg2> onto T1 stack */
986           if ( arg_cnt != 2 )
987             goto Unexpected_OtherSubr;
988 
989           top[0] = ADD_LONG( top[0], top[1] );
990 
991           known_othersubr_result_cnt = 1;
992           break;
993 
994         case 21:
995           /* <arg1> <arg2> 2 21 callothersubr pop   */
996           /* ==> push <arg1> - <arg2> onto T1 stack */
997           if ( arg_cnt != 2 )
998             goto Unexpected_OtherSubr;
999 
1000           top[0] = SUB_LONG( top[0], top[1] );
1001 
1002           known_othersubr_result_cnt = 1;
1003           break;
1004 
1005         case 22:
1006           /* <arg1> <arg2> 2 22 callothersubr pop   */
1007           /* ==> push <arg1> * <arg2> onto T1 stack */
1008           if ( arg_cnt != 2 )
1009             goto Unexpected_OtherSubr;
1010 
1011           top[0] = FT_MulFix( top[0], top[1] );
1012 
1013           known_othersubr_result_cnt = 1;
1014           break;
1015 
1016         case 23:
1017           /* <arg1> <arg2> 2 23 callothersubr pop   */
1018           /* ==> push <arg1> / <arg2> onto T1 stack */
1019           if ( arg_cnt != 2 || top[1] == 0 )
1020             goto Unexpected_OtherSubr;
1021 
1022           top[0] = FT_DivFix( top[0], top[1] );
1023 
1024           known_othersubr_result_cnt = 1;
1025           break;
1026 
1027         case 24:
1028           /* <val> <idx> 2 24 callothersubr               */
1029           /* ==> set BuildCharArray[cvi( <idx> )] = <val> */
1030           {
1031             FT_UInt   idx;
1032             PS_Blend  blend = decoder->blend;
1033 
1034 
1035             if ( arg_cnt != 2 || !blend )
1036               goto Unexpected_OtherSubr;
1037 
1038             idx = Fix2UInt( top[1] );
1039 
1040             if ( idx >= decoder->len_buildchar )
1041               goto Unexpected_OtherSubr;
1042 
1043             decoder->buildchar[idx] = top[0];
1044           }
1045           break;
1046 
1047         case 25:
1048           /* <idx> 1 25 callothersubr pop        */
1049           /* ==> push BuildCharArray[cvi( idx )] */
1050           /*     onto T1 stack                   */
1051           {
1052             FT_UInt   idx;
1053             PS_Blend  blend = decoder->blend;
1054 
1055 
1056             if ( arg_cnt != 1 || !blend )
1057               goto Unexpected_OtherSubr;
1058 
1059             idx = Fix2UInt( top[0] );
1060 
1061             if ( idx >= decoder->len_buildchar )
1062               goto Unexpected_OtherSubr;
1063 
1064             top[0] = decoder->buildchar[idx];
1065           }
1066 
1067           known_othersubr_result_cnt = 1;
1068           break;
1069 
1070 #if 0
1071         case 26:
1072           /* <val> mark <idx> ==> set BuildCharArray[cvi( <idx> )] = <val>, */
1073           /*                      leave mark on T1 stack                    */
1074           /* <val> <idx>      ==> set BuildCharArray[cvi( <idx> )] = <val>  */
1075           XXX which routine has left its mark on the (PostScript) stack?;
1076           break;
1077 #endif
1078 
1079         case 27:
1080           /* <res1> <res2> <val1> <val2> 4 27 callothersubr pop */
1081           /* ==> push <res1> onto T1 stack if <val1> <= <val2>, */
1082           /*     otherwise push <res2>                          */
1083           if ( arg_cnt != 4 )
1084             goto Unexpected_OtherSubr;
1085 
1086           if ( top[2] > top[3] )
1087             top[0] = top[1];
1088 
1089           known_othersubr_result_cnt = 1;
1090           break;
1091 
1092         case 28:
1093           /* 0 28 callothersubr pop                               */
1094           /* => push random value from interval [0, 1) onto stack */
1095           if ( arg_cnt != 0 )
1096             goto Unexpected_OtherSubr;
1097 
1098           {
1099             FT_Fixed  Rand;
1100 
1101 
1102             Rand = seed;
1103             if ( Rand >= 0x8000L )
1104               Rand++;
1105 
1106             top[0] = Rand;
1107 
1108             seed = FT_MulFix( seed, 0x10000L - seed );
1109             if ( seed == 0 )
1110               seed += 0x2873;
1111           }
1112 
1113           known_othersubr_result_cnt = 1;
1114           break;
1115 
1116         default:
1117           if ( arg_cnt >= 0 && subr_no >= 0 )
1118           {
1119             FT_ERROR(( "t1_decoder_parse_charstrings:"
1120                        " unknown othersubr [%d %d], wish me luck\n",
1121                        arg_cnt, subr_no ));
1122             unknown_othersubr_result_cnt = arg_cnt;
1123             break;
1124           }
1125           /* fall through */
1126 
1127         Unexpected_OtherSubr:
1128           FT_ERROR(( "t1_decoder_parse_charstrings:"
1129                      " invalid othersubr [%d %d]\n", arg_cnt, subr_no ));
1130           goto Syntax_Error;
1131         }
1132 
1133         top += known_othersubr_result_cnt;
1134 
1135         decoder->top = top;
1136       }
1137       else  /* general operator */
1138       {
1139         FT_Int  num_args = t1_args_count[op];
1140 
1141 
1142         FT_ASSERT( num_args >= 0 );
1143 
1144         if ( top - decoder->stack < num_args )
1145           goto Stack_Underflow;
1146 
1147         /* XXX Operators usually take their operands from the        */
1148         /*     bottom of the stack, i.e., the operands are           */
1149         /*     decoder->stack[0], ..., decoder->stack[num_args - 1]; */
1150         /*     only div, callsubr, and callothersubr are different.  */
1151         /*     In practice it doesn't matter (?).                    */
1152 
1153 #ifdef FT_DEBUG_LEVEL_TRACE
1154 
1155         switch ( op )
1156         {
1157         case op_callsubr:
1158         case op_div:
1159         case op_callothersubr:
1160         case op_pop:
1161         case op_return:
1162           break;
1163 
1164         default:
1165           if ( top - decoder->stack != num_args )
1166             FT_TRACE0(( "t1_decoder_parse_charstrings:"
1167                         " too much operands on the stack"
1168                         " (seen %td, expected %d)\n",
1169                         top - decoder->stack, num_args ));
1170           break;
1171         }
1172 
1173 #endif /* FT_DEBUG_LEVEL_TRACE */
1174 
1175         top -= num_args;
1176 
1177         switch ( op )
1178         {
1179         case op_endchar:
1180           FT_TRACE4(( " endchar\n" ));
1181 
1182           t1_builder_close_contour( builder );
1183 
1184           /* close hints recording session */
1185           if ( hinter )
1186           {
1187             if ( hinter->close( hinter->hints,
1188                                 (FT_UInt)builder->current->n_points ) )
1189               goto Syntax_Error;
1190 
1191             /* apply hints to the loaded glyph outline now */
1192             error = hinter->apply( hinter->hints,
1193                                    builder->current,
1194                                    (PSH_Globals)builder->hints_globals,
1195                                    decoder->hint_mode );
1196             if ( error )
1197               goto Fail;
1198           }
1199 
1200           /* add current outline to the glyph slot */
1201           FT_GlyphLoader_Add( builder->loader );
1202 
1203           /* the compiler should optimize away this empty loop but ... */
1204 
1205 #ifdef FT_DEBUG_LEVEL_TRACE
1206 
1207           if ( decoder->len_buildchar > 0 )
1208           {
1209             FT_UInt  i;
1210 
1211 
1212             FT_TRACE4(( "BuildCharArray = [ " ));
1213 
1214             for ( i = 0; i < decoder->len_buildchar; i++ )
1215               FT_TRACE4(( "%ld ", decoder->buildchar[i] ));
1216 
1217             FT_TRACE4(( "]\n" ));
1218           }
1219 
1220 #endif /* FT_DEBUG_LEVEL_TRACE */
1221 
1222           FT_TRACE4(( "\n" ));
1223 
1224           /* return now! */
1225           return FT_Err_Ok;
1226 
1227         case op_hsbw:
1228           FT_TRACE4(( " hsbw" ));
1229 
1230           builder->parse_state = T1_Parse_Have_Width;
1231 
1232           builder->left_bearing.x = ADD_LONG( builder->left_bearing.x,
1233                                               top[0] );
1234 
1235           builder->advance.x = top[1];
1236           builder->advance.y = 0;
1237 
1238           orig_x = x = ADD_LONG( builder->pos_x, top[0] );
1239           orig_y = y = builder->pos_y;
1240 
1241           FT_UNUSED( orig_y );
1242 
1243           /* `metrics_only' indicates that we only want to compute the */
1244           /* glyph's metrics (lsb + advance width) without loading the */
1245           /* rest of it; so exit immediately                           */
1246           if ( builder->metrics_only )
1247           {
1248             FT_TRACE4(( "\n" ));
1249             return FT_Err_Ok;
1250           }
1251 
1252           break;
1253 
1254         case op_seac:
1255           return t1operator_seac( decoder,
1256                                   top[0],
1257                                   top[1],
1258                                   top[2],
1259                                   Fix2Int( top[3] ),
1260                                   Fix2Int( top[4] ) );
1261 
1262         case op_sbw:
1263           FT_TRACE4(( " sbw" ));
1264 
1265           builder->parse_state = T1_Parse_Have_Width;
1266 
1267           builder->left_bearing.x = ADD_LONG( builder->left_bearing.x,
1268                                               top[0] );
1269           builder->left_bearing.y = ADD_LONG( builder->left_bearing.y,
1270                                               top[1] );
1271 
1272           builder->advance.x = top[2];
1273           builder->advance.y = top[3];
1274 
1275           x = ADD_LONG( builder->pos_x, top[0] );
1276           y = ADD_LONG( builder->pos_y, top[1] );
1277 
1278           /* `metrics_only' indicates that we only want to compute the */
1279           /* glyph's metrics (lsb + advance width) without loading the */
1280           /* rest of it; so exit immediately                           */
1281           if ( builder->metrics_only )
1282           {
1283             FT_TRACE4(( "\n" ));
1284             return FT_Err_Ok;
1285           }
1286 
1287           break;
1288 
1289         case op_closepath:
1290           FT_TRACE4(( " closepath" ));
1291 
1292           /* if there is no path, `closepath' is a no-op */
1293           if ( builder->parse_state == T1_Parse_Have_Path   ||
1294                builder->parse_state == T1_Parse_Have_Moveto )
1295             t1_builder_close_contour( builder );
1296 
1297           builder->parse_state = T1_Parse_Have_Width;
1298           break;
1299 
1300         case op_hlineto:
1301           FT_TRACE4(( " hlineto" ));
1302 
1303           if ( FT_SET_ERROR( t1_builder_start_point( builder, x, y ) ) )
1304             goto Fail;
1305 
1306           x = ADD_LONG( x, top[0] );
1307           goto Add_Line;
1308 
1309         case op_hmoveto:
1310           FT_TRACE4(( " hmoveto" ));
1311 
1312           x = ADD_LONG( x, top[0] );
1313 
1314           if ( !decoder->flex_state )
1315           {
1316             if ( builder->parse_state == T1_Parse_Start )
1317               goto Syntax_Error;
1318             builder->parse_state = T1_Parse_Have_Moveto;
1319           }
1320           break;
1321 
1322         case op_hvcurveto:
1323           FT_TRACE4(( " hvcurveto" ));
1324 
1325           if ( FT_SET_ERROR( t1_builder_start_point( builder, x, y ) ) ||
1326                FT_SET_ERROR( t1_builder_check_points( builder, 3 ) )   )
1327             goto Fail;
1328 
1329           x = ADD_LONG( x, top[0] );
1330           t1_builder_add_point( builder, x, y, 0 );
1331 
1332           x = ADD_LONG( x, top[1] );
1333           y = ADD_LONG( y, top[2] );
1334           t1_builder_add_point( builder, x, y, 0 );
1335 
1336           y = ADD_LONG( y, top[3] );
1337           t1_builder_add_point( builder, x, y, 1 );
1338           break;
1339 
1340         case op_rlineto:
1341           FT_TRACE4(( " rlineto" ));
1342 
1343           if ( FT_SET_ERROR( t1_builder_start_point( builder, x, y ) ) )
1344             goto Fail;
1345 
1346           x = ADD_LONG( x, top[0] );
1347           y = ADD_LONG( y, top[1] );
1348 
1349         Add_Line:
1350           if ( FT_SET_ERROR( t1_builder_add_point1( builder, x, y ) ) )
1351             goto Fail;
1352           break;
1353 
1354         case op_rmoveto:
1355           FT_TRACE4(( " rmoveto" ));
1356 
1357           x = ADD_LONG( x, top[0] );
1358           y = ADD_LONG( y, top[1] );
1359 
1360           if ( !decoder->flex_state )
1361           {
1362             if ( builder->parse_state == T1_Parse_Start )
1363               goto Syntax_Error;
1364             builder->parse_state = T1_Parse_Have_Moveto;
1365           }
1366           break;
1367 
1368         case op_rrcurveto:
1369           FT_TRACE4(( " rrcurveto" ));
1370 
1371           if ( FT_SET_ERROR( t1_builder_start_point( builder, x, y ) ) ||
1372                FT_SET_ERROR( t1_builder_check_points( builder, 3 ) )   )
1373             goto Fail;
1374 
1375           x = ADD_LONG( x, top[0] );
1376           y = ADD_LONG( y, top[1] );
1377           t1_builder_add_point( builder, x, y, 0 );
1378 
1379           x = ADD_LONG( x, top[2] );
1380           y = ADD_LONG( y, top[3] );
1381           t1_builder_add_point( builder, x, y, 0 );
1382 
1383           x = ADD_LONG( x, top[4] );
1384           y = ADD_LONG( y, top[5] );
1385           t1_builder_add_point( builder, x, y, 1 );
1386           break;
1387 
1388         case op_vhcurveto:
1389           FT_TRACE4(( " vhcurveto" ));
1390 
1391           if ( FT_SET_ERROR( t1_builder_start_point( builder, x, y ) ) ||
1392                FT_SET_ERROR( t1_builder_check_points( builder, 3 ) )   )
1393             goto Fail;
1394 
1395           y = ADD_LONG( y, top[0] );
1396           t1_builder_add_point( builder, x, y, 0 );
1397 
1398           x = ADD_LONG( x, top[1] );
1399           y = ADD_LONG( y, top[2] );
1400           t1_builder_add_point( builder, x, y, 0 );
1401 
1402           x = ADD_LONG( x, top[3] );
1403           t1_builder_add_point( builder, x, y, 1 );
1404           break;
1405 
1406         case op_vlineto:
1407           FT_TRACE4(( " vlineto" ));
1408 
1409           if ( FT_SET_ERROR( t1_builder_start_point( builder, x, y ) ) )
1410             goto Fail;
1411 
1412           y = ADD_LONG( y, top[0] );
1413           goto Add_Line;
1414 
1415         case op_vmoveto:
1416           FT_TRACE4(( " vmoveto" ));
1417 
1418           y = ADD_LONG( y, top[0] );
1419 
1420           if ( !decoder->flex_state )
1421           {
1422             if ( builder->parse_state == T1_Parse_Start )
1423               goto Syntax_Error;
1424             builder->parse_state = T1_Parse_Have_Moveto;
1425           }
1426           break;
1427 
1428         case op_div:
1429           FT_TRACE4(( " div" ));
1430 
1431           /* if `large_int' is set, we divide unscaled numbers; */
1432           /* otherwise, we divide numbers in 16.16 format --    */
1433           /* in both cases, it is the same operation            */
1434           *top = FT_DivFix( top[0], top[1] );
1435           top++;
1436 
1437           large_int = FALSE;
1438           break;
1439 
1440         case op_callsubr:
1441           {
1442             FT_Int  idx;
1443 
1444 
1445             FT_TRACE4(( " callsubr" ));
1446 
1447             idx = Fix2Int( top[0] );
1448 
1449             if ( decoder->subrs_hash )
1450             {
1451               size_t*  val = ft_hash_num_lookup( idx,
1452                                                  decoder->subrs_hash );
1453 
1454 
1455               if ( val )
1456                 idx = *val;
1457               else
1458                 idx = -1;
1459             }
1460 
1461             if ( idx < 0 || idx >= decoder->num_subrs )
1462             {
1463               FT_ERROR(( "t1_decoder_parse_charstrings:"
1464                          " invalid subrs index\n" ));
1465               goto Syntax_Error;
1466             }
1467 
1468             if ( zone - decoder->zones >= T1_MAX_SUBRS_CALLS )
1469             {
1470               FT_ERROR(( "t1_decoder_parse_charstrings:"
1471                          " too many nested subrs\n" ));
1472               goto Syntax_Error;
1473             }
1474 
1475             zone->cursor = ip;  /* save current instruction pointer */
1476 
1477             zone++;
1478 
1479             /* The Type 1 driver stores subroutines without the seed bytes. */
1480             /* The CID driver stores subroutines with seed bytes.  This     */
1481             /* case is taken care of when decoder->subrs_len == 0.          */
1482             zone->base = decoder->subrs[idx];
1483 
1484             if ( decoder->subrs_len )
1485               zone->limit = zone->base + decoder->subrs_len[idx];
1486             else
1487             {
1488               /* We are using subroutines from a CID font.  We must adjust */
1489               /* for the seed bytes.                                       */
1490               zone->base  += ( decoder->lenIV >= 0 ? decoder->lenIV : 0 );
1491               zone->limit  = decoder->subrs[idx + 1];
1492             }
1493 
1494             zone->cursor = zone->base;
1495 
1496             if ( !zone->base )
1497             {
1498               FT_ERROR(( "t1_decoder_parse_charstrings:"
1499                          " invoking empty subrs\n" ));
1500               goto Syntax_Error;
1501             }
1502 
1503             decoder->zone = zone;
1504             ip            = zone->base;
1505             limit         = zone->limit;
1506             break;
1507           }
1508 
1509         case op_pop:
1510           FT_TRACE4(( " pop" ));
1511 
1512           if ( known_othersubr_result_cnt > 0 )
1513           {
1514             known_othersubr_result_cnt--;
1515             /* ignore, we pushed the operands ourselves */
1516             break;
1517           }
1518 
1519           if ( unknown_othersubr_result_cnt == 0 )
1520           {
1521             FT_ERROR(( "t1_decoder_parse_charstrings:"
1522                        " no more operands for othersubr\n" ));
1523             goto Syntax_Error;
1524           }
1525 
1526           unknown_othersubr_result_cnt--;
1527           top++;   /* `push' the operand to callothersubr onto the stack */
1528           break;
1529 
1530         case op_return:
1531           FT_TRACE4(( " return" ));
1532 
1533           if ( zone <= decoder->zones )
1534           {
1535             FT_ERROR(( "t1_decoder_parse_charstrings:"
1536                        " unexpected return\n" ));
1537             goto Syntax_Error;
1538           }
1539 
1540           zone--;
1541           ip            = zone->cursor;
1542           limit         = zone->limit;
1543           decoder->zone = zone;
1544           break;
1545 
1546         case op_dotsection:
1547           FT_TRACE4(( " dotsection" ));
1548 
1549           break;
1550 
1551         case op_hstem:
1552           FT_TRACE4(( " hstem" ));
1553 
1554           /* record horizontal hint */
1555           if ( hinter )
1556           {
1557             /* top[0] += builder->left_bearing.y; */
1558             hinter->stem( hinter->hints, 1, top );
1559           }
1560           break;
1561 
1562         case op_hstem3:
1563           FT_TRACE4(( " hstem3" ));
1564 
1565           /* record horizontal counter-controlled hints */
1566           if ( hinter )
1567             hinter->stem3( hinter->hints, 1, top );
1568           break;
1569 
1570         case op_vstem:
1571           FT_TRACE4(( " vstem" ));
1572 
1573           /* record vertical hint */
1574           if ( hinter )
1575           {
1576             top[0] = ADD_LONG( top[0], orig_x );
1577             hinter->stem( hinter->hints, 0, top );
1578           }
1579           break;
1580 
1581         case op_vstem3:
1582           FT_TRACE4(( " vstem3" ));
1583 
1584           /* record vertical counter-controlled hints */
1585           if ( hinter )
1586           {
1587             FT_Pos  dx = orig_x;
1588 
1589 
1590             top[0] = ADD_LONG( top[0], dx );
1591             top[2] = ADD_LONG( top[2], dx );
1592             top[4] = ADD_LONG( top[4], dx );
1593             hinter->stem3( hinter->hints, 0, top );
1594           }
1595           break;
1596 
1597         case op_setcurrentpoint:
1598           FT_TRACE4(( " setcurrentpoint" ));
1599 
1600           /* From the T1 specification, section 6.4:                */
1601           /*                                                        */
1602           /*   The setcurrentpoint command is used only in          */
1603           /*   conjunction with results from OtherSubrs procedures. */
1604 
1605           /* known_othersubr_result_cnt != 0 is already handled     */
1606           /* above.                                                 */
1607 
1608           /* Note, however, that both Ghostscript and Adobe         */
1609           /* Distiller handle this situation by silently ignoring   */
1610           /* the inappropriate `setcurrentpoint' instruction.  So   */
1611           /* we do the same.                                        */
1612 #if 0
1613 
1614           if ( decoder->flex_state != 1 )
1615           {
1616             FT_ERROR(( "t1_decoder_parse_charstrings:"
1617                        " unexpected `setcurrentpoint'\n" ));
1618             goto Syntax_Error;
1619           }
1620           else
1621             ...
1622 #endif
1623 
1624           x = top[0];
1625           y = top[1];
1626           decoder->flex_state = 0;
1627           break;
1628 
1629         case op_unknown15:
1630           FT_TRACE4(( " opcode_15" ));
1631           /* nothing to do except to pop the two arguments */
1632           break;
1633 
1634         default:
1635           FT_ERROR(( "t1_decoder_parse_charstrings:"
1636                      " unhandled opcode %d\n", op ));
1637           goto Syntax_Error;
1638         }
1639 
1640         /* XXX Operators usually clear the operand stack;  */
1641         /*     only div, callsubr, callothersubr, pop, and */
1642         /*     return are different.                       */
1643         /*     In practice it doesn't matter (?).          */
1644 
1645         decoder->top = top;
1646 
1647 #ifdef FT_DEBUG_LEVEL_TRACE
1648         FT_TRACE4(( "\n" ));
1649         bol = TRUE;
1650 #endif
1651 
1652       } /* general operator processing */
1653 
1654     } /* while ip < limit */
1655 
1656     FT_TRACE4(( "..end..\n" ));
1657     FT_TRACE4(( "\n" ));
1658 
1659   Fail:
1660     return error;
1661 
1662   Syntax_Error:
1663     return FT_THROW( Syntax_Error );
1664 
1665   Stack_Underflow:
1666     return FT_THROW( Stack_Underflow );
1667   }
1668 
1669 
1670 #else /* !T1_CONFIG_OPTION_OLD_ENGINE */
1671 
1672 
1673   /**************************************************************************
1674    *
1675    * @Function:
1676    *   t1_decoder_parse_metrics
1677    *
1678    * @Description:
1679    *   Parses a given Type 1 charstrings program to extract width
1680    *
1681    * @Input:
1682    *   decoder ::
1683    *     The current Type 1 decoder.
1684    *
1685    *   charstring_base ::
1686    *     The base address of the charstring stream.
1687    *
1688    *   charstring_len ::
1689    *     The length in bytes of the charstring stream.
1690    *
1691    * @Return:
1692    *   FreeType error code.  0 means success.
1693    */
1694   FT_LOCAL_DEF( FT_Error )
t1_decoder_parse_metrics(T1_Decoder decoder,FT_Byte * charstring_base,FT_UInt charstring_len)1695   t1_decoder_parse_metrics( T1_Decoder  decoder,
1696                             FT_Byte*    charstring_base,
1697                             FT_UInt     charstring_len )
1698   {
1699     T1_Decoder_Zone  zone;
1700     FT_Byte*         ip;
1701     FT_Byte*         limit;
1702     T1_Builder       builder = &decoder->builder;
1703     FT_Bool          large_int;
1704 
1705 #ifdef FT_DEBUG_LEVEL_TRACE
1706     FT_Bool          bol = TRUE;
1707 #endif
1708 
1709 
1710     /* First of all, initialize the decoder */
1711     decoder->top  = decoder->stack;
1712     decoder->zone = decoder->zones;
1713     zone          = decoder->zones;
1714 
1715     builder->parse_state = T1_Parse_Start;
1716 
1717     zone->base           = charstring_base;
1718     limit = zone->limit  = charstring_base + charstring_len;
1719     ip    = zone->cursor = zone->base;
1720 
1721     large_int = FALSE;
1722 
1723     /* now, execute loop */
1724     while ( ip < limit )
1725     {
1726       FT_Long*     top   = decoder->top;
1727       T1_Operator  op    = op_none;
1728       FT_Int32     value = 0;
1729 
1730 
1731 #ifdef FT_DEBUG_LEVEL_TRACE
1732       if ( bol )
1733       {
1734         FT_TRACE5(( " (%ld)", decoder->top - decoder->stack ));
1735         bol = FALSE;
1736       }
1737 #endif
1738 
1739       /**********************************************************************
1740        *
1741        * Decode operator or operand
1742        *
1743        */
1744 
1745       /* first of all, decompress operator or value */
1746       switch ( *ip++ )
1747       {
1748       case 1:
1749       case 3:
1750       case 4:
1751       case 5:
1752       case 6:
1753       case 7:
1754       case 8:
1755       case 9:
1756       case 14:
1757       case 15:
1758       case 21:
1759       case 22:
1760       case 30:
1761       case 31:
1762         goto No_Width;
1763 
1764       case 10:
1765         op = op_callsubr;
1766         break;
1767       case 11:
1768         op = op_return;
1769         break;
1770 
1771       case 13:
1772         op = op_hsbw;
1773         break;
1774 
1775       case 12:
1776         if ( ip >= limit )
1777         {
1778           FT_ERROR(( "t1_decoder_parse_metrics:"
1779                      " invalid escape (12+EOF)\n" ));
1780           goto Syntax_Error;
1781         }
1782 
1783         switch ( *ip++ )
1784         {
1785         case 7:
1786           op = op_sbw;
1787           break;
1788         case 12:
1789           op = op_div;
1790           break;
1791 
1792         default:
1793           goto No_Width;
1794         }
1795         break;
1796 
1797       case 255:    /* four bytes integer */
1798         if ( ip + 4 > limit )
1799         {
1800           FT_ERROR(( "t1_decoder_parse_metrics:"
1801                      " unexpected EOF in integer\n" ));
1802           goto Syntax_Error;
1803         }
1804 
1805         value = (FT_Int32)( ( (FT_UInt32)ip[0] << 24 ) |
1806                             ( (FT_UInt32)ip[1] << 16 ) |
1807                             ( (FT_UInt32)ip[2] << 8  ) |
1808                               (FT_UInt32)ip[3]         );
1809         ip += 4;
1810 
1811         /* According to the specification, values > 32000 or < -32000 must */
1812         /* be followed by a `div' operator to make the result be in the    */
1813         /* range [-32000;32000].  We expect that the second argument of    */
1814         /* `div' is not a large number.  Additionally, we don't handle     */
1815         /* stuff like `<large1> <large2> <num> div <num> div' or           */
1816         /* <large1> <large2> <num> div div'.  This is probably not allowed */
1817         /* anyway.                                                         */
1818         if ( value > 32000 || value < -32000 )
1819         {
1820           if ( large_int )
1821           {
1822             FT_ERROR(( "t1_decoder_parse_metrics:"
1823                        " no `div' after large integer\n" ));
1824             goto Syntax_Error;
1825           }
1826           else
1827             large_int = TRUE;
1828         }
1829         else
1830         {
1831           if ( !large_int )
1832             value = (FT_Int32)( (FT_UInt32)value << 16 );
1833         }
1834 
1835         break;
1836 
1837       default:
1838         if ( ip[-1] >= 32 )
1839         {
1840           if ( ip[-1] < 247 )
1841             value = (FT_Int32)ip[-1] - 139;
1842           else
1843           {
1844             if ( ++ip > limit )
1845             {
1846               FT_ERROR(( "t1_decoder_parse_metrics:"
1847                          " unexpected EOF in integer\n" ));
1848               goto Syntax_Error;
1849             }
1850 
1851             if ( ip[-2] < 251 )
1852               value =    ( ( ip[-2] - 247 ) * 256 ) + ip[-1] + 108;
1853             else
1854               value = -( ( ( ip[-2] - 251 ) * 256 ) + ip[-1] + 108 );
1855           }
1856 
1857           if ( !large_int )
1858             value = (FT_Int32)( (FT_UInt32)value << 16 );
1859         }
1860         else
1861         {
1862           FT_ERROR(( "t1_decoder_parse_metrics:"
1863                      " invalid byte (%d)\n", ip[-1] ));
1864           goto Syntax_Error;
1865         }
1866       }
1867 
1868       if ( large_int && !( op == op_none || op == op_div ) )
1869       {
1870         FT_ERROR(( "t1_decoder_parse_metrics:"
1871                    " no `div' after large integer\n" ));
1872         goto Syntax_Error;
1873       }
1874 
1875       /**********************************************************************
1876        *
1877        * Push value on stack, or process operator
1878        *
1879        */
1880       if ( op == op_none )
1881       {
1882         if ( top - decoder->stack >= T1_MAX_CHARSTRINGS_OPERANDS )
1883         {
1884           FT_ERROR(( "t1_decoder_parse_metrics: stack overflow\n" ));
1885           goto Syntax_Error;
1886         }
1887 
1888 #ifdef FT_DEBUG_LEVEL_TRACE
1889         if ( large_int )
1890           FT_TRACE4(( " %d", value ));
1891         else
1892           FT_TRACE4(( " %d", value / 65536 ));
1893 #endif
1894 
1895         *top++       = value;
1896         decoder->top = top;
1897       }
1898       else  /* general operator */
1899       {
1900         FT_Int  num_args = t1_args_count[op];
1901 
1902 
1903         FT_ASSERT( num_args >= 0 );
1904 
1905         if ( top - decoder->stack < num_args )
1906           goto Stack_Underflow;
1907 
1908 #ifdef FT_DEBUG_LEVEL_TRACE
1909 
1910         switch ( op )
1911         {
1912         case op_callsubr:
1913         case op_div:
1914         case op_return:
1915           break;
1916 
1917         default:
1918           if ( top - decoder->stack != num_args )
1919             FT_TRACE0(( "t1_decoder_parse_metrics:"
1920                         " too much operands on the stack"
1921                         " (seen %ld, expected %d)\n",
1922                         top - decoder->stack, num_args ));
1923           break;
1924         }
1925 
1926 #endif /* FT_DEBUG_LEVEL_TRACE */
1927 
1928         top -= num_args;
1929 
1930         switch ( op )
1931         {
1932         case op_hsbw:
1933           FT_TRACE4(( " hsbw" ));
1934 
1935           builder->parse_state = T1_Parse_Have_Width;
1936 
1937           builder->left_bearing.x = ADD_LONG( builder->left_bearing.x,
1938                                               top[0] );
1939 
1940           builder->advance.x = top[1];
1941           builder->advance.y = 0;
1942 
1943           /* we only want to compute the glyph's metrics */
1944           /* (lsb + advance width) without loading the   */
1945           /* rest of it; so exit immediately             */
1946           FT_TRACE4(( "\n" ));
1947           return FT_Err_Ok;
1948 
1949         case op_sbw:
1950           FT_TRACE4(( " sbw" ));
1951 
1952           builder->parse_state = T1_Parse_Have_Width;
1953 
1954           builder->left_bearing.x = ADD_LONG( builder->left_bearing.x,
1955                                               top[0] );
1956           builder->left_bearing.y = ADD_LONG( builder->left_bearing.y,
1957                                               top[1] );
1958 
1959           builder->advance.x = top[2];
1960           builder->advance.y = top[3];
1961 
1962           /* we only want to compute the glyph's metrics */
1963           /* (lsb + advance width), without loading the  */
1964           /* rest of it; so exit immediately             */
1965           FT_TRACE4(( "\n" ));
1966           return FT_Err_Ok;
1967 
1968         case op_div:
1969           FT_TRACE4(( " div" ));
1970 
1971           /* if `large_int' is set, we divide unscaled numbers; */
1972           /* otherwise, we divide numbers in 16.16 format --    */
1973           /* in both cases, it is the same operation            */
1974           *top = FT_DivFix( top[0], top[1] );
1975           top++;
1976 
1977           large_int = FALSE;
1978           break;
1979 
1980         case op_callsubr:
1981           {
1982             FT_Int  idx;
1983 
1984 
1985             FT_TRACE4(( " callsubr" ));
1986 
1987             idx = Fix2Int( top[0] );
1988 
1989             if ( decoder->subrs_hash )
1990             {
1991               size_t*  val = ft_hash_num_lookup( idx,
1992                                                  decoder->subrs_hash );
1993 
1994 
1995               if ( val )
1996                 idx = *val;
1997               else
1998                 idx = -1;
1999             }
2000 
2001             if ( idx < 0 || idx >= decoder->num_subrs )
2002             {
2003               FT_ERROR(( "t1_decoder_parse_metrics:"
2004                          " invalid subrs index\n" ));
2005               goto Syntax_Error;
2006             }
2007 
2008             if ( zone - decoder->zones >= T1_MAX_SUBRS_CALLS )
2009             {
2010               FT_ERROR(( "t1_decoder_parse_metrics:"
2011                          " too many nested subrs\n" ));
2012               goto Syntax_Error;
2013             }
2014 
2015             zone->cursor = ip;  /* save current instruction pointer */
2016 
2017             zone++;
2018 
2019             /* The Type 1 driver stores subroutines without the seed bytes. */
2020             /* The CID driver stores subroutines with seed bytes.  This     */
2021             /* case is taken care of when decoder->subrs_len == 0.          */
2022             zone->base = decoder->subrs[idx];
2023 
2024             if ( decoder->subrs_len )
2025               zone->limit = zone->base + decoder->subrs_len[idx];
2026             else
2027             {
2028               /* We are using subroutines from a CID font.  We must adjust */
2029               /* for the seed bytes.                                       */
2030               zone->base  += ( decoder->lenIV >= 0 ? decoder->lenIV : 0 );
2031               zone->limit  = decoder->subrs[idx + 1];
2032             }
2033 
2034             zone->cursor = zone->base;
2035 
2036             if ( !zone->base )
2037             {
2038               FT_ERROR(( "t1_decoder_parse_metrics:"
2039                          " invoking empty subrs\n" ));
2040               goto Syntax_Error;
2041             }
2042 
2043             decoder->zone = zone;
2044             ip            = zone->base;
2045             limit         = zone->limit;
2046             break;
2047           }
2048 
2049         case op_return:
2050           FT_TRACE4(( " return" ));
2051 
2052           if ( zone <= decoder->zones )
2053           {
2054             FT_ERROR(( "t1_decoder_parse_metrics:"
2055                        " unexpected return\n" ));
2056             goto Syntax_Error;
2057           }
2058 
2059           zone--;
2060           ip            = zone->cursor;
2061           limit         = zone->limit;
2062           decoder->zone = zone;
2063           break;
2064 
2065         default:
2066           FT_ERROR(( "t1_decoder_parse_metrics:"
2067                      " unhandled opcode %d\n", op ));
2068           goto Syntax_Error;
2069         }
2070 
2071         decoder->top = top;
2072 
2073       } /* general operator processing */
2074 
2075     } /* while ip < limit */
2076 
2077     FT_TRACE4(( "..end..\n" ));
2078     FT_TRACE4(( "\n" ));
2079 
2080   No_Width:
2081     FT_ERROR(( "t1_decoder_parse_metrics:"
2082                " no width, found op %d instead\n",
2083                ip[-1] ));
2084   Syntax_Error:
2085     return FT_THROW( Syntax_Error );
2086 
2087   Stack_Underflow:
2088     return FT_THROW( Stack_Underflow );
2089   }
2090 
2091 #endif /* !T1_CONFIG_OPTION_OLD_ENGINE */
2092 
2093 
2094   /* initialize T1 decoder */
2095   FT_LOCAL_DEF( FT_Error )
t1_decoder_init(T1_Decoder decoder,FT_Face face,FT_Size size,FT_GlyphSlot slot,FT_Byte ** glyph_names,PS_Blend blend,FT_Bool hinting,FT_Render_Mode hint_mode,T1_Decoder_Callback parse_callback)2096   t1_decoder_init( T1_Decoder           decoder,
2097                    FT_Face              face,
2098                    FT_Size              size,
2099                    FT_GlyphSlot         slot,
2100                    FT_Byte**            glyph_names,
2101                    PS_Blend             blend,
2102                    FT_Bool              hinting,
2103                    FT_Render_Mode       hint_mode,
2104                    T1_Decoder_Callback  parse_callback )
2105   {
2106     FT_ZERO( decoder );
2107 
2108     /* retrieve `psnames' interface from list of current modules */
2109     {
2110       FT_Service_PsCMaps  psnames;
2111 
2112 
2113       FT_FACE_FIND_GLOBAL_SERVICE( face, psnames, POSTSCRIPT_CMAPS );
2114       if ( !psnames )
2115       {
2116         FT_ERROR(( "t1_decoder_init:"
2117                    " the `psnames' module is not available\n" ));
2118         return FT_THROW( Unimplemented_Feature );
2119       }
2120 
2121       decoder->psnames = psnames;
2122     }
2123 
2124     t1_builder_init( &decoder->builder, face, size, slot, hinting );
2125 
2126     /* decoder->buildchar and decoder->len_buildchar have to be  */
2127     /* initialized by the caller since we cannot know the length */
2128     /* of the BuildCharArray                                     */
2129 
2130     decoder->num_glyphs     = (FT_UInt)face->num_glyphs;
2131     decoder->glyph_names    = glyph_names;
2132     decoder->hint_mode      = hint_mode;
2133     decoder->blend          = blend;
2134     decoder->parse_callback = parse_callback;
2135 
2136     decoder->funcs          = t1_decoder_funcs;
2137 
2138     return FT_Err_Ok;
2139   }
2140 
2141 
2142   /* finalize T1 decoder */
2143   FT_LOCAL_DEF( void )
t1_decoder_done(T1_Decoder decoder)2144   t1_decoder_done( T1_Decoder  decoder )
2145   {
2146     FT_Memory  memory = decoder->builder.memory;
2147 
2148 
2149     t1_builder_done( &decoder->builder );
2150 
2151     if ( decoder->cf2_instance.finalizer )
2152     {
2153       decoder->cf2_instance.finalizer( decoder->cf2_instance.data );
2154       FT_FREE( decoder->cf2_instance.data );
2155     }
2156   }
2157 
2158 
2159 /* END */
2160