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1 /***************************************************************************/
2 /*                                                                         */
3 /*  cffdecode.c                                                            */
4 /*                                                                         */
5 /*    PostScript CFF (Type 2) decoding routines (body).                    */
6 /*                                                                         */
7 /*  Copyright 2017-2018 by                                                 */
8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
9 /*                                                                         */
10 /*  This file is part of the FreeType project, and may only be used,       */
11 /*  modified, and distributed under the terms of the FreeType project      */
12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
13 /*  this file you indicate that you have read the license and              */
14 /*  understand and accept it fully.                                        */
15 /*                                                                         */
16 /***************************************************************************/
17 
18 
19 #include <ft2build.h>
20 #include FT_FREETYPE_H
21 #include FT_INTERNAL_DEBUG_H
22 #include FT_INTERNAL_SERVICE_H
23 #include FT_SERVICE_CFF_TABLE_LOAD_H
24 
25 #include "cffdecode.h"
26 #include "psobjs.h"
27 
28 #include "psauxerr.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_cffdecode
39 
40 
41 #ifdef CFF_CONFIG_OPTION_OLD_ENGINE
42 
43   typedef enum  CFF_Operator_
44   {
45     cff_op_unknown = 0,
46 
47     cff_op_rmoveto,
48     cff_op_hmoveto,
49     cff_op_vmoveto,
50 
51     cff_op_rlineto,
52     cff_op_hlineto,
53     cff_op_vlineto,
54 
55     cff_op_rrcurveto,
56     cff_op_hhcurveto,
57     cff_op_hvcurveto,
58     cff_op_rcurveline,
59     cff_op_rlinecurve,
60     cff_op_vhcurveto,
61     cff_op_vvcurveto,
62 
63     cff_op_flex,
64     cff_op_hflex,
65     cff_op_hflex1,
66     cff_op_flex1,
67 
68     cff_op_endchar,
69 
70     cff_op_hstem,
71     cff_op_vstem,
72     cff_op_hstemhm,
73     cff_op_vstemhm,
74 
75     cff_op_hintmask,
76     cff_op_cntrmask,
77     cff_op_dotsection,  /* deprecated, acts as no-op */
78 
79     cff_op_abs,
80     cff_op_add,
81     cff_op_sub,
82     cff_op_div,
83     cff_op_neg,
84     cff_op_random,
85     cff_op_mul,
86     cff_op_sqrt,
87 
88     cff_op_blend,
89 
90     cff_op_drop,
91     cff_op_exch,
92     cff_op_index,
93     cff_op_roll,
94     cff_op_dup,
95 
96     cff_op_put,
97     cff_op_get,
98     cff_op_store,
99     cff_op_load,
100 
101     cff_op_and,
102     cff_op_or,
103     cff_op_not,
104     cff_op_eq,
105     cff_op_ifelse,
106 
107     cff_op_callsubr,
108     cff_op_callgsubr,
109     cff_op_return,
110 
111     /* Type 1 opcodes: invalid but seen in real life */
112     cff_op_hsbw,
113     cff_op_closepath,
114     cff_op_callothersubr,
115     cff_op_pop,
116     cff_op_seac,
117     cff_op_sbw,
118     cff_op_setcurrentpoint,
119 
120     /* do not remove */
121     cff_op_max
122 
123   } CFF_Operator;
124 
125 
126 #define CFF_COUNT_CHECK_WIDTH  0x80
127 #define CFF_COUNT_EXACT        0x40
128 #define CFF_COUNT_CLEAR_STACK  0x20
129 
130   /* count values which have the `CFF_COUNT_CHECK_WIDTH' flag set are  */
131   /* used for checking the width and requested numbers of arguments    */
132   /* only; they are set to zero afterwards                             */
133 
134   /* the other two flags are informative only and unused currently     */
135 
136   static const FT_Byte  cff_argument_counts[] =
137   {
138     0,  /* unknown */
139 
140     2 | CFF_COUNT_CHECK_WIDTH | CFF_COUNT_EXACT, /* rmoveto */
141     1 | CFF_COUNT_CHECK_WIDTH | CFF_COUNT_EXACT,
142     1 | CFF_COUNT_CHECK_WIDTH | CFF_COUNT_EXACT,
143 
144     0 | CFF_COUNT_CLEAR_STACK, /* rlineto */
145     0 | CFF_COUNT_CLEAR_STACK,
146     0 | CFF_COUNT_CLEAR_STACK,
147 
148     0 | CFF_COUNT_CLEAR_STACK, /* rrcurveto */
149     0 | CFF_COUNT_CLEAR_STACK,
150     0 | CFF_COUNT_CLEAR_STACK,
151     0 | CFF_COUNT_CLEAR_STACK,
152     0 | CFF_COUNT_CLEAR_STACK,
153     0 | CFF_COUNT_CLEAR_STACK,
154     0 | CFF_COUNT_CLEAR_STACK,
155 
156     13, /* flex */
157     7,
158     9,
159     11,
160 
161     0 | CFF_COUNT_CHECK_WIDTH, /* endchar */
162 
163     2 | CFF_COUNT_CHECK_WIDTH, /* hstem */
164     2 | CFF_COUNT_CHECK_WIDTH,
165     2 | CFF_COUNT_CHECK_WIDTH,
166     2 | CFF_COUNT_CHECK_WIDTH,
167 
168     0 | CFF_COUNT_CHECK_WIDTH, /* hintmask */
169     0 | CFF_COUNT_CHECK_WIDTH, /* cntrmask */
170     0, /* dotsection */
171 
172     1, /* abs */
173     2,
174     2,
175     2,
176     1,
177     0,
178     2,
179     1,
180 
181     1, /* blend */
182 
183     1, /* drop */
184     2,
185     1,
186     2,
187     1,
188 
189     2, /* put */
190     1,
191     4,
192     3,
193 
194     2, /* and */
195     2,
196     1,
197     2,
198     4,
199 
200     1, /* callsubr */
201     1,
202     0,
203 
204     2, /* hsbw */
205     0,
206     0,
207     0,
208     5, /* seac */
209     4, /* sbw */
210     2  /* setcurrentpoint */
211   };
212 
213 
214   static FT_Error
cff_operator_seac(CFF_Decoder * decoder,FT_Pos asb,FT_Pos adx,FT_Pos ady,FT_Int bchar,FT_Int achar)215   cff_operator_seac( CFF_Decoder*  decoder,
216                      FT_Pos        asb,
217                      FT_Pos        adx,
218                      FT_Pos        ady,
219                      FT_Int        bchar,
220                      FT_Int        achar )
221   {
222     FT_Error      error;
223     CFF_Builder*  builder = &decoder->builder;
224     FT_Int        bchar_index, achar_index;
225     TT_Face       face    = decoder->builder.face;
226     FT_Vector     left_bearing, advance;
227     FT_Byte*      charstring;
228     FT_ULong      charstring_len;
229     FT_Pos        glyph_width;
230 
231 
232     if ( decoder->seac )
233     {
234       FT_ERROR(( "cff_operator_seac: invalid nested seac\n" ));
235       return FT_THROW( Syntax_Error );
236     }
237 
238     adx += decoder->builder.left_bearing.x;
239     ady += decoder->builder.left_bearing.y;
240 
241 #ifdef FT_CONFIG_OPTION_INCREMENTAL
242     /* Incremental fonts don't necessarily have valid charsets.        */
243     /* They use the character code, not the glyph index, in this case. */
244     if ( face->root.internal->incremental_interface )
245     {
246       bchar_index = bchar;
247       achar_index = achar;
248     }
249     else
250 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
251     {
252       CFF_Font cff = (CFF_Font)(face->extra.data);
253 
254 
255       bchar_index = cff_lookup_glyph_by_stdcharcode( cff, bchar );
256       achar_index = cff_lookup_glyph_by_stdcharcode( cff, achar );
257     }
258 
259     if ( bchar_index < 0 || achar_index < 0 )
260     {
261       FT_ERROR(( "cff_operator_seac:"
262                  " invalid seac character code arguments\n" ));
263       return FT_THROW( Syntax_Error );
264     }
265 
266     /* If we are trying to load a composite glyph, do not load the */
267     /* accent character and return the array of subglyphs.         */
268     if ( builder->no_recurse )
269     {
270       FT_GlyphSlot    glyph  = (FT_GlyphSlot)builder->glyph;
271       FT_GlyphLoader  loader = glyph->internal->loader;
272       FT_SubGlyph     subg;
273 
274 
275       /* reallocate subglyph array if necessary */
276       error = FT_GlyphLoader_CheckSubGlyphs( loader, 2 );
277       if ( error )
278         goto Exit;
279 
280       subg = loader->current.subglyphs;
281 
282       /* subglyph 0 = base character */
283       subg->index = bchar_index;
284       subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES |
285                     FT_SUBGLYPH_FLAG_USE_MY_METRICS;
286       subg->arg1  = 0;
287       subg->arg2  = 0;
288       subg++;
289 
290       /* subglyph 1 = accent character */
291       subg->index = achar_index;
292       subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES;
293       subg->arg1  = (FT_Int)( adx >> 16 );
294       subg->arg2  = (FT_Int)( ady >> 16 );
295 
296       /* set up remaining glyph fields */
297       glyph->num_subglyphs = 2;
298       glyph->subglyphs     = loader->base.subglyphs;
299       glyph->format        = FT_GLYPH_FORMAT_COMPOSITE;
300 
301       loader->current.num_subglyphs = 2;
302     }
303 
304     FT_GlyphLoader_Prepare( builder->loader );
305 
306     /* First load `bchar' in builder */
307     error = decoder->get_glyph_callback( face, (FT_UInt)bchar_index,
308                                          &charstring, &charstring_len );
309     if ( !error )
310     {
311       /* the seac operator must not be nested */
312       decoder->seac = TRUE;
313       error = cff_decoder_parse_charstrings( decoder, charstring,
314                                              charstring_len, 0 );
315       decoder->seac = FALSE;
316 
317       decoder->free_glyph_callback( face, &charstring, charstring_len );
318 
319       if ( error )
320         goto Exit;
321     }
322 
323     /* Save the left bearing, advance and glyph width of the base */
324     /* character as they will be erased by the next load.         */
325 
326     left_bearing = builder->left_bearing;
327     advance      = builder->advance;
328     glyph_width  = decoder->glyph_width;
329 
330     builder->left_bearing.x = 0;
331     builder->left_bearing.y = 0;
332 
333     builder->pos_x = adx - asb;
334     builder->pos_y = ady;
335 
336     /* Now load `achar' on top of the base outline. */
337     error = decoder->get_glyph_callback( face, (FT_UInt)achar_index,
338                                          &charstring, &charstring_len );
339     if ( !error )
340     {
341       /* the seac operator must not be nested */
342       decoder->seac = TRUE;
343       error = cff_decoder_parse_charstrings( decoder, charstring,
344                                              charstring_len, 0 );
345       decoder->seac = FALSE;
346 
347       decoder->free_glyph_callback( face, &charstring, charstring_len );
348 
349       if ( error )
350         goto Exit;
351     }
352 
353     /* Restore the left side bearing, advance and glyph width */
354     /* of the base character.                                 */
355     builder->left_bearing = left_bearing;
356     builder->advance      = advance;
357     decoder->glyph_width  = glyph_width;
358 
359     builder->pos_x = 0;
360     builder->pos_y = 0;
361 
362   Exit:
363     return error;
364   }
365 
366 #endif /* CFF_CONFIG_OPTION_OLD_ENGINE */
367 
368 
369   /*************************************************************************/
370   /*************************************************************************/
371   /*************************************************************************/
372   /**********                                                      *********/
373   /**********                                                      *********/
374   /**********             GENERIC CHARSTRING PARSING               *********/
375   /**********                                                      *********/
376   /**********                                                      *********/
377   /*************************************************************************/
378   /*************************************************************************/
379   /*************************************************************************/
380 
381   /*************************************************************************/
382   /*                                                                       */
383   /* <Function>                                                            */
384   /*    cff_compute_bias                                                   */
385   /*                                                                       */
386   /* <Description>                                                         */
387   /*    Computes the bias value in dependence of the number of glyph       */
388   /*    subroutines.                                                       */
389   /*                                                                       */
390   /* <Input>                                                               */
391   /*    in_charstring_type :: The `CharstringType' value of the top DICT   */
392   /*                          dictionary.                                  */
393   /*                                                                       */
394   /*    num_subrs          :: The number of glyph subroutines.             */
395   /*                                                                       */
396   /* <Return>                                                              */
397   /*    The bias value.                                                    */
398   static FT_Int
cff_compute_bias(FT_Int in_charstring_type,FT_UInt num_subrs)399   cff_compute_bias( FT_Int   in_charstring_type,
400                     FT_UInt  num_subrs )
401   {
402     FT_Int  result;
403 
404 
405     if ( in_charstring_type == 1 )
406       result = 0;
407     else if ( num_subrs < 1240 )
408       result = 107;
409     else if ( num_subrs < 33900U )
410       result = 1131;
411     else
412       result = 32768U;
413 
414     return result;
415   }
416 
417 
418   FT_LOCAL_DEF( FT_Int )
cff_lookup_glyph_by_stdcharcode(CFF_Font cff,FT_Int charcode)419   cff_lookup_glyph_by_stdcharcode( CFF_Font  cff,
420                                    FT_Int    charcode )
421   {
422     FT_UInt    n;
423     FT_UShort  glyph_sid;
424 
425     FT_Service_CFFLoad  cffload;
426 
427 
428     /* CID-keyed fonts don't have glyph names */
429     if ( !cff->charset.sids )
430       return -1;
431 
432     /* check range of standard char code */
433     if ( charcode < 0 || charcode > 255 )
434       return -1;
435 
436 #if 0
437     /* retrieve cffload from list of current modules */
438     FT_Service_CFFLoad  cffload;
439 
440 
441     FT_FACE_FIND_GLOBAL_SERVICE( face, cffload, CFF_LOAD );
442     if ( !cffload )
443     {
444       FT_ERROR(( "cff_lookup_glyph_by_stdcharcode:"
445                  " the `cffload' module is not available\n" ));
446       return FT_THROW( Unimplemented_Feature );
447     }
448 #endif
449 
450     cffload = (FT_Service_CFFLoad)cff->cffload;
451 
452     /* Get code to SID mapping from `cff_standard_encoding'. */
453     glyph_sid = cffload->get_standard_encoding( (FT_UInt)charcode );
454 
455     for ( n = 0; n < cff->num_glyphs; n++ )
456     {
457       if ( cff->charset.sids[n] == glyph_sid )
458         return (FT_Int)n;
459     }
460 
461     return -1;
462   }
463 
464 
465 #ifdef CFF_CONFIG_OPTION_OLD_ENGINE
466 
467   /*************************************************************************/
468   /*                                                                       */
469   /* <Function>                                                            */
470   /*    cff_decoder_parse_charstrings                                      */
471   /*                                                                       */
472   /* <Description>                                                         */
473   /*    Parses a given Type 2 charstrings program.                         */
474   /*                                                                       */
475   /* <InOut>                                                               */
476   /*    decoder         :: The current Type 1 decoder.                     */
477   /*                                                                       */
478   /* <Input>                                                               */
479   /*    charstring_base :: The base of the charstring stream.              */
480   /*                                                                       */
481   /*    charstring_len  :: The length in bytes of the charstring stream.   */
482   /*                                                                       */
483   /*    in_dict         :: Set to 1 if function is called from top or      */
484   /*                       private DICT (needed for Multiple Master CFFs). */
485   /*                                                                       */
486   /* <Return>                                                              */
487   /*    FreeType error code.  0 means success.                             */
488   /*                                                                       */
489   FT_LOCAL_DEF( FT_Error )
cff_decoder_parse_charstrings(CFF_Decoder * decoder,FT_Byte * charstring_base,FT_ULong charstring_len,FT_Bool in_dict)490   cff_decoder_parse_charstrings( CFF_Decoder*  decoder,
491                                  FT_Byte*      charstring_base,
492                                  FT_ULong      charstring_len,
493                                  FT_Bool       in_dict )
494   {
495     FT_Error           error;
496     CFF_Decoder_Zone*  zone;
497     FT_Byte*           ip;
498     FT_Byte*           limit;
499     CFF_Builder*       builder = &decoder->builder;
500     FT_Pos             x, y;
501     FT_Fixed*          stack;
502     FT_Int             charstring_type =
503                          decoder->cff->top_font.font_dict.charstring_type;
504     FT_UShort          num_designs =
505                          decoder->cff->top_font.font_dict.num_designs;
506     FT_UShort          num_axes =
507                          decoder->cff->top_font.font_dict.num_axes;
508 
509     T2_Hints_Funcs  hinter;
510 
511 
512     /* set default width */
513     decoder->num_hints  = 0;
514     decoder->read_width = 1;
515 
516     /* initialize the decoder */
517     decoder->top  = decoder->stack;
518     decoder->zone = decoder->zones;
519     zone          = decoder->zones;
520     stack         = decoder->top;
521 
522     hinter = (T2_Hints_Funcs)builder->hints_funcs;
523 
524     builder->path_begun = 0;
525 
526     zone->base           = charstring_base;
527     limit = zone->limit  = charstring_base + charstring_len;
528     ip    = zone->cursor = zone->base;
529 
530     error = FT_Err_Ok;
531 
532     x = builder->pos_x;
533     y = builder->pos_y;
534 
535     /* begin hints recording session, if any */
536     if ( hinter )
537       hinter->open( hinter->hints );
538 
539     /* now execute loop */
540     while ( ip < limit )
541     {
542       CFF_Operator  op;
543       FT_Byte       v;
544 
545 
546       /********************************************************************/
547       /*                                                                  */
548       /* Decode operator or operand                                       */
549       /*                                                                  */
550       v = *ip++;
551       if ( v >= 32 || v == 28 )
552       {
553         FT_Int    shift = 16;
554         FT_Int32  val;
555 
556 
557         /* this is an operand, push it on the stack */
558 
559         /* if we use shifts, all computations are done with unsigned */
560         /* values; the conversion to a signed value is the last step */
561         if ( v == 28 )
562         {
563           if ( ip + 1 >= limit )
564             goto Syntax_Error;
565           val = (FT_Short)( ( (FT_UShort)ip[0] << 8 ) | ip[1] );
566           ip += 2;
567         }
568         else if ( v < 247 )
569           val = (FT_Int32)v - 139;
570         else if ( v < 251 )
571         {
572           if ( ip >= limit )
573             goto Syntax_Error;
574           val = ( (FT_Int32)v - 247 ) * 256 + *ip++ + 108;
575         }
576         else if ( v < 255 )
577         {
578           if ( ip >= limit )
579             goto Syntax_Error;
580           val = -( (FT_Int32)v - 251 ) * 256 - *ip++ - 108;
581         }
582         else
583         {
584           if ( ip + 3 >= limit )
585             goto Syntax_Error;
586           val = (FT_Int32)( ( (FT_UInt32)ip[0] << 24 ) |
587                             ( (FT_UInt32)ip[1] << 16 ) |
588                             ( (FT_UInt32)ip[2] <<  8 ) |
589                               (FT_UInt32)ip[3]         );
590           ip += 4;
591           if ( charstring_type == 2 )
592             shift = 0;
593         }
594         if ( decoder->top - stack >= CFF_MAX_OPERANDS )
595           goto Stack_Overflow;
596 
597         val             = (FT_Int32)( (FT_UInt32)val << shift );
598         *decoder->top++ = val;
599 
600 #ifdef FT_DEBUG_LEVEL_TRACE
601         if ( !( val & 0xFFFFL ) )
602           FT_TRACE4(( " %hd", (FT_Short)( (FT_UInt32)val >> 16 ) ));
603         else
604           FT_TRACE4(( " %.5f", val / 65536.0 ));
605 #endif
606 
607       }
608       else
609       {
610         /* The specification says that normally arguments are to be taken */
611         /* from the bottom of the stack.  However, this seems not to be   */
612         /* correct, at least for Acroread 7.0.8 on GNU/Linux: It pops the */
613         /* arguments similar to a PS interpreter.                         */
614 
615         FT_Fixed*  args     = decoder->top;
616         FT_Int     num_args = (FT_Int)( args - decoder->stack );
617         FT_Int     req_args;
618 
619 
620         /* find operator */
621         op = cff_op_unknown;
622 
623         switch ( v )
624         {
625         case 1:
626           op = cff_op_hstem;
627           break;
628         case 3:
629           op = cff_op_vstem;
630           break;
631         case 4:
632           op = cff_op_vmoveto;
633           break;
634         case 5:
635           op = cff_op_rlineto;
636           break;
637         case 6:
638           op = cff_op_hlineto;
639           break;
640         case 7:
641           op = cff_op_vlineto;
642           break;
643         case 8:
644           op = cff_op_rrcurveto;
645           break;
646         case 9:
647           op = cff_op_closepath;
648           break;
649         case 10:
650           op = cff_op_callsubr;
651           break;
652         case 11:
653           op = cff_op_return;
654           break;
655         case 12:
656           if ( ip >= limit )
657             goto Syntax_Error;
658           v = *ip++;
659 
660           switch ( v )
661           {
662           case 0:
663             op = cff_op_dotsection;
664             break;
665           case 1: /* this is actually the Type1 vstem3 operator */
666             op = cff_op_vstem;
667             break;
668           case 2: /* this is actually the Type1 hstem3 operator */
669             op = cff_op_hstem;
670             break;
671           case 3:
672             op = cff_op_and;
673             break;
674           case 4:
675             op = cff_op_or;
676             break;
677           case 5:
678             op = cff_op_not;
679             break;
680           case 6:
681             op = cff_op_seac;
682             break;
683           case 7:
684             op = cff_op_sbw;
685             break;
686           case 8:
687             op = cff_op_store;
688             break;
689           case 9:
690             op = cff_op_abs;
691             break;
692           case 10:
693             op = cff_op_add;
694             break;
695           case 11:
696             op = cff_op_sub;
697             break;
698           case 12:
699             op = cff_op_div;
700             break;
701           case 13:
702             op = cff_op_load;
703             break;
704           case 14:
705             op = cff_op_neg;
706             break;
707           case 15:
708             op = cff_op_eq;
709             break;
710           case 16:
711             op = cff_op_callothersubr;
712             break;
713           case 17:
714             op = cff_op_pop;
715             break;
716           case 18:
717             op = cff_op_drop;
718             break;
719           case 20:
720             op = cff_op_put;
721             break;
722           case 21:
723             op = cff_op_get;
724             break;
725           case 22:
726             op = cff_op_ifelse;
727             break;
728           case 23:
729             op = cff_op_random;
730             break;
731           case 24:
732             op = cff_op_mul;
733             break;
734           case 26:
735             op = cff_op_sqrt;
736             break;
737           case 27:
738             op = cff_op_dup;
739             break;
740           case 28:
741             op = cff_op_exch;
742             break;
743           case 29:
744             op = cff_op_index;
745             break;
746           case 30:
747             op = cff_op_roll;
748             break;
749           case 33:
750             op = cff_op_setcurrentpoint;
751             break;
752           case 34:
753             op = cff_op_hflex;
754             break;
755           case 35:
756             op = cff_op_flex;
757             break;
758           case 36:
759             op = cff_op_hflex1;
760             break;
761           case 37:
762             op = cff_op_flex1;
763             break;
764           default:
765             FT_TRACE4(( " unknown op (12, %d)\n", v ));
766             break;
767           }
768           break;
769         case 13:
770           op = cff_op_hsbw;
771           break;
772         case 14:
773           op = cff_op_endchar;
774           break;
775         case 16:
776           op = cff_op_blend;
777           break;
778         case 18:
779           op = cff_op_hstemhm;
780           break;
781         case 19:
782           op = cff_op_hintmask;
783           break;
784         case 20:
785           op = cff_op_cntrmask;
786           break;
787         case 21:
788           op = cff_op_rmoveto;
789           break;
790         case 22:
791           op = cff_op_hmoveto;
792           break;
793         case 23:
794           op = cff_op_vstemhm;
795           break;
796         case 24:
797           op = cff_op_rcurveline;
798           break;
799         case 25:
800           op = cff_op_rlinecurve;
801           break;
802         case 26:
803           op = cff_op_vvcurveto;
804           break;
805         case 27:
806           op = cff_op_hhcurveto;
807           break;
808         case 29:
809           op = cff_op_callgsubr;
810           break;
811         case 30:
812           op = cff_op_vhcurveto;
813           break;
814         case 31:
815           op = cff_op_hvcurveto;
816           break;
817         default:
818           FT_TRACE4(( " unknown op (%d)\n", v ));
819           break;
820         }
821 
822         if ( op == cff_op_unknown )
823           continue;
824 
825         /* in Multiple Master CFFs, T2 charstrings can appear in */
826         /* dictionaries, but some operators are prohibited       */
827         if ( in_dict )
828         {
829           switch ( op )
830           {
831           case cff_op_hstem:
832           case cff_op_vstem:
833           case cff_op_vmoveto:
834           case cff_op_rlineto:
835           case cff_op_hlineto:
836           case cff_op_vlineto:
837           case cff_op_rrcurveto:
838           case cff_op_hstemhm:
839           case cff_op_hintmask:
840           case cff_op_cntrmask:
841           case cff_op_rmoveto:
842           case cff_op_hmoveto:
843           case cff_op_vstemhm:
844           case cff_op_rcurveline:
845           case cff_op_rlinecurve:
846           case cff_op_vvcurveto:
847           case cff_op_hhcurveto:
848           case cff_op_vhcurveto:
849           case cff_op_hvcurveto:
850           case cff_op_hflex:
851           case cff_op_flex:
852           case cff_op_hflex1:
853           case cff_op_flex1:
854           case cff_op_callsubr:
855           case cff_op_callgsubr:
856             goto MM_Error;
857 
858           default:
859             break;
860           }
861         }
862 
863         /* check arguments */
864         req_args = cff_argument_counts[op];
865         if ( req_args & CFF_COUNT_CHECK_WIDTH )
866         {
867           if ( num_args > 0 && decoder->read_width )
868           {
869             /* If `nominal_width' is non-zero, the number is really a      */
870             /* difference against `nominal_width'.  Else, the number here  */
871             /* is truly a width, not a difference against `nominal_width'. */
872             /* If the font does not set `nominal_width', then              */
873             /* `nominal_width' defaults to zero, and so we can set         */
874             /* `glyph_width' to `nominal_width' plus number on the stack   */
875             /* -- for either case.                                         */
876 
877             FT_Int  set_width_ok;
878 
879 
880             switch ( op )
881             {
882             case cff_op_hmoveto:
883             case cff_op_vmoveto:
884               set_width_ok = num_args & 2;
885               break;
886 
887             case cff_op_hstem:
888             case cff_op_vstem:
889             case cff_op_hstemhm:
890             case cff_op_vstemhm:
891             case cff_op_rmoveto:
892             case cff_op_hintmask:
893             case cff_op_cntrmask:
894               set_width_ok = num_args & 1;
895               break;
896 
897             case cff_op_endchar:
898               /* If there is a width specified for endchar, we either have */
899               /* 1 argument or 5 arguments.  We like to argue.             */
900               set_width_ok = in_dict
901                                ? 0
902                                : ( ( num_args == 5 ) || ( num_args == 1 ) );
903               break;
904 
905             default:
906               set_width_ok = 0;
907               break;
908             }
909 
910             if ( set_width_ok )
911             {
912               decoder->glyph_width = decoder->nominal_width +
913                                        ( stack[0] >> 16 );
914 
915               if ( decoder->width_only )
916               {
917                 /* we only want the advance width; stop here */
918                 break;
919               }
920 
921               /* Consumed an argument. */
922               num_args--;
923             }
924           }
925 
926           decoder->read_width = 0;
927           req_args            = 0;
928         }
929 
930         req_args &= 0x000F;
931         if ( num_args < req_args )
932           goto Stack_Underflow;
933         args     -= req_args;
934         num_args -= req_args;
935 
936         /* At this point, `args' points to the first argument of the  */
937         /* operand in case `req_args' isn't zero.  Otherwise, we have */
938         /* to adjust `args' manually.                                 */
939 
940         /* Note that we only pop arguments from the stack which we    */
941         /* really need and can digest so that we can continue in case */
942         /* of superfluous stack elements.                             */
943 
944         switch ( op )
945         {
946         case cff_op_hstem:
947         case cff_op_vstem:
948         case cff_op_hstemhm:
949         case cff_op_vstemhm:
950           /* the number of arguments is always even here */
951           FT_TRACE4((
952               op == cff_op_hstem   ? " hstem\n"   :
953             ( op == cff_op_vstem   ? " vstem\n"   :
954             ( op == cff_op_hstemhm ? " hstemhm\n" : " vstemhm\n" ) ) ));
955 
956           if ( hinter )
957             hinter->stems( hinter->hints,
958                            ( op == cff_op_hstem || op == cff_op_hstemhm ),
959                            num_args / 2,
960                            args - ( num_args & ~1 ) );
961 
962           decoder->num_hints += num_args / 2;
963           args = stack;
964           break;
965 
966         case cff_op_hintmask:
967         case cff_op_cntrmask:
968           FT_TRACE4(( op == cff_op_hintmask ? " hintmask" : " cntrmask" ));
969 
970           /* implement vstem when needed --                        */
971           /* the specification doesn't say it, but this also works */
972           /* with the 'cntrmask' operator                          */
973           /*                                                       */
974           if ( num_args > 0 )
975           {
976             if ( hinter )
977               hinter->stems( hinter->hints,
978                              0,
979                              num_args / 2,
980                              args - ( num_args & ~1 ) );
981 
982             decoder->num_hints += num_args / 2;
983           }
984 
985           /* In a valid charstring there must be at least one byte */
986           /* after `hintmask' or `cntrmask' (e.g., for a `return'  */
987           /* instruction).  Additionally, there must be space for  */
988           /* `num_hints' bits.                                     */
989 
990           if ( ( ip + ( ( decoder->num_hints + 7 ) >> 3 ) ) >= limit )
991             goto Syntax_Error;
992 
993           if ( hinter )
994           {
995             if ( op == cff_op_hintmask )
996               hinter->hintmask( hinter->hints,
997                                 (FT_UInt)builder->current->n_points,
998                                 (FT_UInt)decoder->num_hints,
999                                 ip );
1000             else
1001               hinter->counter( hinter->hints,
1002                                (FT_UInt)decoder->num_hints,
1003                                ip );
1004           }
1005 
1006 #ifdef FT_DEBUG_LEVEL_TRACE
1007           {
1008             FT_UInt  maskbyte;
1009 
1010 
1011             FT_TRACE4(( " (maskbytes:" ));
1012 
1013             for ( maskbyte = 0;
1014                   maskbyte < (FT_UInt)( ( decoder->num_hints + 7 ) >> 3 );
1015                   maskbyte++, ip++ )
1016               FT_TRACE4(( " 0x%02X", *ip ));
1017 
1018             FT_TRACE4(( ")\n" ));
1019           }
1020 #else
1021           ip += ( decoder->num_hints + 7 ) >> 3;
1022 #endif
1023           args = stack;
1024           break;
1025 
1026         case cff_op_rmoveto:
1027           FT_TRACE4(( " rmoveto\n" ));
1028 
1029           cff_builder_close_contour( builder );
1030           builder->path_begun = 0;
1031           x    = ADD_LONG( x, args[-2] );
1032           y    = ADD_LONG( y, args[-1] );
1033           args = stack;
1034           break;
1035 
1036         case cff_op_vmoveto:
1037           FT_TRACE4(( " vmoveto\n" ));
1038 
1039           cff_builder_close_contour( builder );
1040           builder->path_begun = 0;
1041           y    = ADD_LONG( y, args[-1] );
1042           args = stack;
1043           break;
1044 
1045         case cff_op_hmoveto:
1046           FT_TRACE4(( " hmoveto\n" ));
1047 
1048           cff_builder_close_contour( builder );
1049           builder->path_begun = 0;
1050           x    = ADD_LONG( x, args[-1] );
1051           args = stack;
1052           break;
1053 
1054         case cff_op_rlineto:
1055           FT_TRACE4(( " rlineto\n" ));
1056 
1057           if ( cff_builder_start_point( builder, x, y )  ||
1058                cff_check_points( builder, num_args / 2 ) )
1059             goto Fail;
1060 
1061           if ( num_args < 2 )
1062             goto Stack_Underflow;
1063 
1064           args -= num_args & ~1;
1065           while ( args < decoder->top )
1066           {
1067             x = ADD_LONG( x, args[0] );
1068             y = ADD_LONG( y, args[1] );
1069             cff_builder_add_point( builder, x, y, 1 );
1070             args += 2;
1071           }
1072           args = stack;
1073           break;
1074 
1075         case cff_op_hlineto:
1076         case cff_op_vlineto:
1077           {
1078             FT_Int  phase = ( op == cff_op_hlineto );
1079 
1080 
1081             FT_TRACE4(( op == cff_op_hlineto ? " hlineto\n"
1082                                              : " vlineto\n" ));
1083 
1084             if ( num_args < 0 )
1085               goto Stack_Underflow;
1086 
1087             /* there exist subsetted fonts (found in PDFs) */
1088             /* which call `hlineto' without arguments      */
1089             if ( num_args == 0 )
1090               break;
1091 
1092             if ( cff_builder_start_point( builder, x, y ) ||
1093                  cff_check_points( builder, num_args )    )
1094               goto Fail;
1095 
1096             args = stack;
1097             while ( args < decoder->top )
1098             {
1099               if ( phase )
1100                 x = ADD_LONG( x, args[0] );
1101               else
1102                 y = ADD_LONG( y, args[0] );
1103 
1104               if ( cff_builder_add_point1( builder, x, y ) )
1105                 goto Fail;
1106 
1107               args++;
1108               phase ^= 1;
1109             }
1110             args = stack;
1111           }
1112           break;
1113 
1114         case cff_op_rrcurveto:
1115           {
1116             FT_Int  nargs;
1117 
1118 
1119             FT_TRACE4(( " rrcurveto\n" ));
1120 
1121             if ( num_args < 6 )
1122               goto Stack_Underflow;
1123 
1124             nargs = num_args - num_args % 6;
1125 
1126             if ( cff_builder_start_point( builder, x, y ) ||
1127                  cff_check_points( builder, nargs / 2 )   )
1128               goto Fail;
1129 
1130             args -= nargs;
1131             while ( args < decoder->top )
1132             {
1133               x = ADD_LONG( x, args[0] );
1134               y = ADD_LONG( y, args[1] );
1135               cff_builder_add_point( builder, x, y, 0 );
1136 
1137               x = ADD_LONG( x, args[2] );
1138               y = ADD_LONG( y, args[3] );
1139               cff_builder_add_point( builder, x, y, 0 );
1140 
1141               x = ADD_LONG( x, args[4] );
1142               y = ADD_LONG( y, args[5] );
1143               cff_builder_add_point( builder, x, y, 1 );
1144 
1145               args += 6;
1146             }
1147             args = stack;
1148           }
1149           break;
1150 
1151         case cff_op_vvcurveto:
1152           {
1153             FT_Int  nargs;
1154 
1155 
1156             FT_TRACE4(( " vvcurveto\n" ));
1157 
1158             if ( num_args < 4 )
1159               goto Stack_Underflow;
1160 
1161             /* if num_args isn't of the form 4n or 4n+1, */
1162             /* we enforce it by clearing the second bit  */
1163 
1164             nargs = num_args & ~2;
1165 
1166             if ( cff_builder_start_point( builder, x, y ) )
1167               goto Fail;
1168 
1169             args -= nargs;
1170 
1171             if ( nargs & 1 )
1172             {
1173               x = ADD_LONG( x, args[0] );
1174               args++;
1175               nargs--;
1176             }
1177 
1178             if ( cff_check_points( builder, 3 * ( nargs / 4 ) ) )
1179               goto Fail;
1180 
1181             while ( args < decoder->top )
1182             {
1183               y = ADD_LONG( y, args[0] );
1184               cff_builder_add_point( builder, x, y, 0 );
1185 
1186               x = ADD_LONG( x, args[1] );
1187               y = ADD_LONG( y, args[2] );
1188               cff_builder_add_point( builder, x, y, 0 );
1189 
1190               y = ADD_LONG( y, args[3] );
1191               cff_builder_add_point( builder, x, y, 1 );
1192 
1193               args += 4;
1194             }
1195             args = stack;
1196           }
1197           break;
1198 
1199         case cff_op_hhcurveto:
1200           {
1201             FT_Int  nargs;
1202 
1203 
1204             FT_TRACE4(( " hhcurveto\n" ));
1205 
1206             if ( num_args < 4 )
1207               goto Stack_Underflow;
1208 
1209             /* if num_args isn't of the form 4n or 4n+1, */
1210             /* we enforce it by clearing the second bit  */
1211 
1212             nargs = num_args & ~2;
1213 
1214             if ( cff_builder_start_point( builder, x, y ) )
1215               goto Fail;
1216 
1217             args -= nargs;
1218             if ( nargs & 1 )
1219             {
1220               y = ADD_LONG( y, args[0] );
1221               args++;
1222               nargs--;
1223             }
1224 
1225             if ( cff_check_points( builder, 3 * ( nargs / 4 ) ) )
1226               goto Fail;
1227 
1228             while ( args < decoder->top )
1229             {
1230               x = ADD_LONG( x, args[0] );
1231               cff_builder_add_point( builder, x, y, 0 );
1232 
1233               x = ADD_LONG( x, args[1] );
1234               y = ADD_LONG( y, args[2] );
1235               cff_builder_add_point( builder, x, y, 0 );
1236 
1237               x = ADD_LONG( x, args[3] );
1238               cff_builder_add_point( builder, x, y, 1 );
1239 
1240               args += 4;
1241             }
1242             args = stack;
1243           }
1244           break;
1245 
1246         case cff_op_vhcurveto:
1247         case cff_op_hvcurveto:
1248           {
1249             FT_Int  phase;
1250             FT_Int  nargs;
1251 
1252 
1253             FT_TRACE4(( op == cff_op_vhcurveto ? " vhcurveto\n"
1254                                                : " hvcurveto\n" ));
1255 
1256             if ( cff_builder_start_point( builder, x, y ) )
1257               goto Fail;
1258 
1259             if ( num_args < 4 )
1260               goto Stack_Underflow;
1261 
1262             /* if num_args isn't of the form 8n, 8n+1, 8n+4, or 8n+5, */
1263             /* we enforce it by clearing the second bit               */
1264 
1265             nargs = num_args & ~2;
1266 
1267             args -= nargs;
1268             if ( cff_check_points( builder, ( nargs / 4 ) * 3 ) )
1269               goto Stack_Underflow;
1270 
1271             phase = ( op == cff_op_hvcurveto );
1272 
1273             while ( nargs >= 4 )
1274             {
1275               nargs -= 4;
1276               if ( phase )
1277               {
1278                 x = ADD_LONG( x, args[0] );
1279                 cff_builder_add_point( builder, x, y, 0 );
1280 
1281                 x = ADD_LONG( x, args[1] );
1282                 y = ADD_LONG( y, args[2] );
1283                 cff_builder_add_point( builder, x, y, 0 );
1284 
1285                 y = ADD_LONG( y, args[3] );
1286                 if ( nargs == 1 )
1287                   x = ADD_LONG( x, args[4] );
1288                 cff_builder_add_point( builder, x, y, 1 );
1289               }
1290               else
1291               {
1292                 y = ADD_LONG( y, args[0] );
1293                 cff_builder_add_point( builder, x, y, 0 );
1294 
1295                 x = ADD_LONG( x, args[1] );
1296                 y = ADD_LONG( y, args[2] );
1297                 cff_builder_add_point( builder, x, y, 0 );
1298 
1299                 x = ADD_LONG( x, args[3] );
1300                 if ( nargs == 1 )
1301                   y = ADD_LONG( y, args[4] );
1302                 cff_builder_add_point( builder, x, y, 1 );
1303               }
1304               args  += 4;
1305               phase ^= 1;
1306             }
1307             args = stack;
1308           }
1309           break;
1310 
1311         case cff_op_rlinecurve:
1312           {
1313             FT_Int  num_lines;
1314             FT_Int  nargs;
1315 
1316 
1317             FT_TRACE4(( " rlinecurve\n" ));
1318 
1319             if ( num_args < 8 )
1320               goto Stack_Underflow;
1321 
1322             nargs     = num_args & ~1;
1323             num_lines = ( nargs - 6 ) / 2;
1324 
1325             if ( cff_builder_start_point( builder, x, y )   ||
1326                  cff_check_points( builder, num_lines + 3 ) )
1327               goto Fail;
1328 
1329             args -= nargs;
1330 
1331             /* first, add the line segments */
1332             while ( num_lines > 0 )
1333             {
1334               x = ADD_LONG( x, args[0] );
1335               y = ADD_LONG( y, args[1] );
1336               cff_builder_add_point( builder, x, y, 1 );
1337 
1338               args += 2;
1339               num_lines--;
1340             }
1341 
1342             /* then the curve */
1343             x = ADD_LONG( x, args[0] );
1344             y = ADD_LONG( y, args[1] );
1345             cff_builder_add_point( builder, x, y, 0 );
1346 
1347             x = ADD_LONG( x, args[2] );
1348             y = ADD_LONG( y, args[3] );
1349             cff_builder_add_point( builder, x, y, 0 );
1350 
1351             x = ADD_LONG( x, args[4] );
1352             y = ADD_LONG( y, args[5] );
1353             cff_builder_add_point( builder, x, y, 1 );
1354 
1355             args = stack;
1356           }
1357           break;
1358 
1359         case cff_op_rcurveline:
1360           {
1361             FT_Int  num_curves;
1362             FT_Int  nargs;
1363 
1364 
1365             FT_TRACE4(( " rcurveline\n" ));
1366 
1367             if ( num_args < 8 )
1368               goto Stack_Underflow;
1369 
1370             nargs      = num_args - 2;
1371             nargs      = nargs - nargs % 6 + 2;
1372             num_curves = ( nargs - 2 ) / 6;
1373 
1374             if ( cff_builder_start_point( builder, x, y )        ||
1375                  cff_check_points( builder, num_curves * 3 + 2 ) )
1376               goto Fail;
1377 
1378             args -= nargs;
1379 
1380             /* first, add the curves */
1381             while ( num_curves > 0 )
1382             {
1383               x = ADD_LONG( x, args[0] );
1384               y = ADD_LONG( y, args[1] );
1385               cff_builder_add_point( builder, x, y, 0 );
1386 
1387               x = ADD_LONG( x, args[2] );
1388               y = ADD_LONG( y, args[3] );
1389               cff_builder_add_point( builder, x, y, 0 );
1390 
1391               x = ADD_LONG( x, args[4] );
1392               y = ADD_LONG( y, args[5] );
1393               cff_builder_add_point( builder, x, y, 1 );
1394 
1395               args += 6;
1396               num_curves--;
1397             }
1398 
1399             /* then the final line */
1400             x = ADD_LONG( x, args[0] );
1401             y = ADD_LONG( y, args[1] );
1402             cff_builder_add_point( builder, x, y, 1 );
1403 
1404             args = stack;
1405           }
1406           break;
1407 
1408         case cff_op_hflex1:
1409           {
1410             FT_Pos  start_y;
1411 
1412 
1413             FT_TRACE4(( " hflex1\n" ));
1414 
1415             /* adding five more points: 4 control points, 1 on-curve point */
1416             /* -- make sure we have enough space for the start point if it */
1417             /* needs to be added                                           */
1418             if ( cff_builder_start_point( builder, x, y ) ||
1419                  cff_check_points( builder, 6 )           )
1420               goto Fail;
1421 
1422             /* record the starting point's y position for later use */
1423             start_y = y;
1424 
1425             /* first control point */
1426             x = ADD_LONG( x, args[0] );
1427             y = ADD_LONG( y, args[1] );
1428             cff_builder_add_point( builder, x, y, 0 );
1429 
1430             /* second control point */
1431             x = ADD_LONG( x, args[2] );
1432             y = ADD_LONG( y, args[3] );
1433             cff_builder_add_point( builder, x, y, 0 );
1434 
1435             /* join point; on curve, with y-value the same as the last */
1436             /* control point's y-value                                 */
1437             x = ADD_LONG( x, args[4] );
1438             cff_builder_add_point( builder, x, y, 1 );
1439 
1440             /* third control point, with y-value the same as the join */
1441             /* point's y-value                                        */
1442             x = ADD_LONG( x, args[5] );
1443             cff_builder_add_point( builder, x, y, 0 );
1444 
1445             /* fourth control point */
1446             x = ADD_LONG( x, args[6] );
1447             y = ADD_LONG( y, args[7] );
1448             cff_builder_add_point( builder, x, y, 0 );
1449 
1450             /* ending point, with y-value the same as the start   */
1451             x = ADD_LONG( x, args[8] );
1452             y = start_y;
1453             cff_builder_add_point( builder, x, y, 1 );
1454 
1455             args = stack;
1456             break;
1457           }
1458 
1459         case cff_op_hflex:
1460           {
1461             FT_Pos  start_y;
1462 
1463 
1464             FT_TRACE4(( " hflex\n" ));
1465 
1466             /* adding six more points; 4 control points, 2 on-curve points */
1467             if ( cff_builder_start_point( builder, x, y ) ||
1468                  cff_check_points( builder, 6 )           )
1469               goto Fail;
1470 
1471             /* record the starting point's y-position for later use */
1472             start_y = y;
1473 
1474             /* first control point */
1475             x = ADD_LONG( x, args[0] );
1476             cff_builder_add_point( builder, x, y, 0 );
1477 
1478             /* second control point */
1479             x = ADD_LONG( x, args[1] );
1480             y = ADD_LONG( y, args[2] );
1481             cff_builder_add_point( builder, x, y, 0 );
1482 
1483             /* join point; on curve, with y-value the same as the last */
1484             /* control point's y-value                                 */
1485             x = ADD_LONG( x, args[3] );
1486             cff_builder_add_point( builder, x, y, 1 );
1487 
1488             /* third control point, with y-value the same as the join */
1489             /* point's y-value                                        */
1490             x = ADD_LONG( x, args[4] );
1491             cff_builder_add_point( builder, x, y, 0 );
1492 
1493             /* fourth control point */
1494             x = ADD_LONG( x, args[5] );
1495             y = start_y;
1496             cff_builder_add_point( builder, x, y, 0 );
1497 
1498             /* ending point, with y-value the same as the start point's */
1499             /* y-value -- we don't add this point, though               */
1500             x = ADD_LONG( x, args[6] );
1501             cff_builder_add_point( builder, x, y, 1 );
1502 
1503             args = stack;
1504             break;
1505           }
1506 
1507         case cff_op_flex1:
1508           {
1509             FT_Pos     start_x, start_y; /* record start x, y values for */
1510                                          /* alter use                    */
1511             FT_Fixed   dx = 0, dy = 0;   /* used in horizontal/vertical  */
1512                                          /* algorithm below              */
1513             FT_Int     horizontal, count;
1514             FT_Fixed*  temp;
1515 
1516 
1517             FT_TRACE4(( " flex1\n" ));
1518 
1519             /* adding six more points; 4 control points, 2 on-curve points */
1520             if ( cff_builder_start_point( builder, x, y ) ||
1521                  cff_check_points( builder, 6 )           )
1522               goto Fail;
1523 
1524             /* record the starting point's x, y position for later use */
1525             start_x = x;
1526             start_y = y;
1527 
1528             /* XXX: figure out whether this is supposed to be a horizontal */
1529             /*      or vertical flex; the Type 2 specification is vague... */
1530 
1531             temp = args;
1532 
1533             /* grab up to the last argument */
1534             for ( count = 5; count > 0; count-- )
1535             {
1536               dx    = ADD_LONG( dx, temp[0] );
1537               dy    = ADD_LONG( dy, temp[1] );
1538               temp += 2;
1539             }
1540 
1541             if ( dx < 0 )
1542               dx = -dx;
1543             if ( dy < 0 )
1544               dy = -dy;
1545 
1546             /* strange test, but here it is... */
1547             horizontal = ( dx > dy );
1548 
1549             for ( count = 5; count > 0; count-- )
1550             {
1551               x = ADD_LONG( x, args[0] );
1552               y = ADD_LONG( y, args[1] );
1553               cff_builder_add_point( builder, x, y,
1554                                      (FT_Bool)( count == 3 ) );
1555               args += 2;
1556             }
1557 
1558             /* is last operand an x- or y-delta? */
1559             if ( horizontal )
1560             {
1561               x = ADD_LONG( x, args[0] );
1562               y = start_y;
1563             }
1564             else
1565             {
1566               x = start_x;
1567               y = ADD_LONG( y, args[0] );
1568             }
1569 
1570             cff_builder_add_point( builder, x, y, 1 );
1571 
1572             args = stack;
1573             break;
1574            }
1575 
1576         case cff_op_flex:
1577           {
1578             FT_UInt  count;
1579 
1580 
1581             FT_TRACE4(( " flex\n" ));
1582 
1583             if ( cff_builder_start_point( builder, x, y ) ||
1584                  cff_check_points( builder, 6 )           )
1585               goto Fail;
1586 
1587             for ( count = 6; count > 0; count-- )
1588             {
1589               x = ADD_LONG( x, args[0] );
1590               y = ADD_LONG( y, args[1] );
1591               cff_builder_add_point( builder, x, y,
1592                                      (FT_Bool)( count == 4 || count == 1 ) );
1593               args += 2;
1594             }
1595 
1596             args = stack;
1597           }
1598           break;
1599 
1600         case cff_op_seac:
1601           FT_TRACE4(( " seac\n" ));
1602 
1603           error = cff_operator_seac( decoder,
1604                                      args[0], args[1], args[2],
1605                                      (FT_Int)( args[3] >> 16 ),
1606                                      (FT_Int)( args[4] >> 16 ) );
1607 
1608           /* add current outline to the glyph slot */
1609           FT_GlyphLoader_Add( builder->loader );
1610 
1611           /* return now! */
1612           FT_TRACE4(( "\n" ));
1613           return error;
1614 
1615         case cff_op_endchar:
1616           /* in dictionaries, `endchar' simply indicates end of data */
1617           if ( in_dict )
1618             return error;
1619 
1620           FT_TRACE4(( " endchar\n" ));
1621 
1622           /* We are going to emulate the seac operator. */
1623           if ( num_args >= 4 )
1624           {
1625             /* Save glyph width so that the subglyphs don't overwrite it. */
1626             FT_Pos  glyph_width = decoder->glyph_width;
1627 
1628 
1629             error = cff_operator_seac( decoder,
1630                                        0L, args[-4], args[-3],
1631                                        (FT_Int)( args[-2] >> 16 ),
1632                                        (FT_Int)( args[-1] >> 16 ) );
1633 
1634             decoder->glyph_width = glyph_width;
1635           }
1636           else
1637           {
1638             cff_builder_close_contour( builder );
1639 
1640             /* close hints recording session */
1641             if ( hinter )
1642             {
1643               if ( hinter->close( hinter->hints,
1644                                   (FT_UInt)builder->current->n_points ) )
1645                 goto Syntax_Error;
1646 
1647               /* apply hints to the loaded glyph outline now */
1648               error = hinter->apply( hinter->hints,
1649                                      builder->current,
1650                                      (PSH_Globals)builder->hints_globals,
1651                                      decoder->hint_mode );
1652               if ( error )
1653                 goto Fail;
1654             }
1655 
1656             /* add current outline to the glyph slot */
1657             FT_GlyphLoader_Add( builder->loader );
1658           }
1659 
1660           /* return now! */
1661           FT_TRACE4(( "\n" ));
1662           return error;
1663 
1664         case cff_op_abs:
1665           FT_TRACE4(( " abs\n" ));
1666 
1667           if ( args[0] < 0 )
1668           {
1669             if ( args[0] == FT_LONG_MIN )
1670               args[0] = FT_LONG_MAX;
1671             else
1672               args[0] = -args[0];
1673           }
1674           args++;
1675           break;
1676 
1677         case cff_op_add:
1678           FT_TRACE4(( " add\n" ));
1679 
1680           args[0] = ADD_LONG( args[0], args[1] );
1681           args++;
1682           break;
1683 
1684         case cff_op_sub:
1685           FT_TRACE4(( " sub\n" ));
1686 
1687           args[0] = SUB_LONG( args[0], args[1] );
1688           args++;
1689           break;
1690 
1691         case cff_op_div:
1692           FT_TRACE4(( " div\n" ));
1693 
1694           args[0] = FT_DivFix( args[0], args[1] );
1695           args++;
1696           break;
1697 
1698         case cff_op_neg:
1699           FT_TRACE4(( " neg\n" ));
1700 
1701           if ( args[0] == FT_LONG_MIN )
1702             args[0] = FT_LONG_MAX;
1703           args[0] = -args[0];
1704           args++;
1705           break;
1706 
1707         case cff_op_random:
1708           FT_TRACE4(( " random\n" ));
1709 
1710           /* only use the lower 16 bits of `random'  */
1711           /* to generate a number in the range (0;1] */
1712           args[0] = (FT_Fixed)
1713                       ( ( decoder->current_subfont->random & 0xFFFF ) + 1 );
1714           args++;
1715 
1716           decoder->current_subfont->random =
1717             cff_random( decoder->current_subfont->random );
1718           break;
1719 
1720         case cff_op_mul:
1721           FT_TRACE4(( " mul\n" ));
1722 
1723           args[0] = FT_MulFix( args[0], args[1] );
1724           args++;
1725           break;
1726 
1727         case cff_op_sqrt:
1728           FT_TRACE4(( " sqrt\n" ));
1729 
1730           if ( args[0] > 0 )
1731           {
1732             FT_Fixed  root = args[0];
1733             FT_Fixed  new_root;
1734 
1735 
1736             for (;;)
1737             {
1738               new_root = ( root + FT_DivFix( args[0], root ) + 1 ) >> 1;
1739               if ( new_root == root )
1740                 break;
1741               root = new_root;
1742             }
1743             args[0] = new_root;
1744           }
1745           else
1746             args[0] = 0;
1747           args++;
1748           break;
1749 
1750         case cff_op_drop:
1751           /* nothing */
1752           FT_TRACE4(( " drop\n" ));
1753 
1754           break;
1755 
1756         case cff_op_exch:
1757           {
1758             FT_Fixed  tmp;
1759 
1760 
1761             FT_TRACE4(( " exch\n" ));
1762 
1763             tmp     = args[0];
1764             args[0] = args[1];
1765             args[1] = tmp;
1766             args   += 2;
1767           }
1768           break;
1769 
1770         case cff_op_index:
1771           {
1772             FT_Int  idx = (FT_Int)( args[0] >> 16 );
1773 
1774 
1775             FT_TRACE4(( " index\n" ));
1776 
1777             if ( idx < 0 )
1778               idx = 0;
1779             else if ( idx > num_args - 2 )
1780               idx = num_args - 2;
1781             args[0] = args[-( idx + 1 )];
1782             args++;
1783           }
1784           break;
1785 
1786         case cff_op_roll:
1787           {
1788             FT_Int  count = (FT_Int)( args[0] >> 16 );
1789             FT_Int  idx   = (FT_Int)( args[1] >> 16 );
1790 
1791 
1792             FT_TRACE4(( " roll\n" ));
1793 
1794             if ( count <= 0 )
1795               count = 1;
1796 
1797             args -= count;
1798             if ( args < stack )
1799               goto Stack_Underflow;
1800 
1801             if ( idx >= 0 )
1802             {
1803               while ( idx > 0 )
1804               {
1805                 FT_Fixed  tmp = args[count - 1];
1806                 FT_Int    i;
1807 
1808 
1809                 for ( i = count - 2; i >= 0; i-- )
1810                   args[i + 1] = args[i];
1811                 args[0] = tmp;
1812                 idx--;
1813               }
1814             }
1815             else
1816             {
1817               while ( idx < 0 )
1818               {
1819                 FT_Fixed  tmp = args[0];
1820                 FT_Int    i;
1821 
1822 
1823                 for ( i = 0; i < count - 1; i++ )
1824                   args[i] = args[i + 1];
1825                 args[count - 1] = tmp;
1826                 idx++;
1827               }
1828             }
1829             args += count;
1830           }
1831           break;
1832 
1833         case cff_op_dup:
1834           FT_TRACE4(( " dup\n" ));
1835 
1836           args[1] = args[0];
1837           args   += 2;
1838           break;
1839 
1840         case cff_op_put:
1841           {
1842             FT_Fixed  val = args[0];
1843             FT_Int    idx = (FT_Int)( args[1] >> 16 );
1844 
1845 
1846             FT_TRACE4(( " put\n" ));
1847 
1848             /* the Type2 specification before version 16-March-2000 */
1849             /* didn't give a hard-coded size limit of the temporary */
1850             /* storage array; instead, an argument of the           */
1851             /* `MultipleMaster' operator set the size               */
1852             if ( idx >= 0 && idx < CFF_MAX_TRANS_ELEMENTS )
1853               decoder->buildchar[idx] = val;
1854           }
1855           break;
1856 
1857         case cff_op_get:
1858           {
1859             FT_Int    idx = (FT_Int)( args[0] >> 16 );
1860             FT_Fixed  val = 0;
1861 
1862 
1863             FT_TRACE4(( " get\n" ));
1864 
1865             if ( idx >= 0 && idx < CFF_MAX_TRANS_ELEMENTS )
1866               val = decoder->buildchar[idx];
1867 
1868             args[0] = val;
1869             args++;
1870           }
1871           break;
1872 
1873         case cff_op_store:
1874           /* this operator was removed from the Type2 specification */
1875           /* in version 16-March-2000                               */
1876 
1877           /* since we currently don't handle interpolation of multiple */
1878           /* master fonts, this is a no-op                             */
1879           FT_TRACE4(( " store\n" ));
1880           break;
1881 
1882         case cff_op_load:
1883           /* this operator was removed from the Type2 specification */
1884           /* in version 16-March-2000                               */
1885           {
1886             FT_Int  reg_idx = (FT_Int)args[0];
1887             FT_Int  idx     = (FT_Int)args[1];
1888             FT_Int  count   = (FT_Int)args[2];
1889 
1890 
1891             FT_TRACE4(( " load\n" ));
1892 
1893             /* since we currently don't handle interpolation of multiple */
1894             /* master fonts, we store a vector [1 0 0 ...] in the        */
1895             /* temporary storage array regardless of the Registry index  */
1896             if ( reg_idx >= 0 && reg_idx <= 2             &&
1897                  idx >= 0 && idx < CFF_MAX_TRANS_ELEMENTS &&
1898                  count >= 0 && count <= num_axes          )
1899             {
1900               FT_Int  end, i;
1901 
1902 
1903               end = FT_MIN( idx + count, CFF_MAX_TRANS_ELEMENTS );
1904 
1905               if ( idx < end )
1906                 decoder->buildchar[idx] = 1 << 16;
1907 
1908               for ( i = idx + 1; i < end; i++ )
1909                 decoder->buildchar[i] = 0;
1910             }
1911           }
1912           break;
1913 
1914         case cff_op_blend:
1915           /* this operator was removed from the Type2 specification */
1916           /* in version 16-March-2000                               */
1917           {
1918             FT_Int  num_results = (FT_Int)( args[0] >> 16 );
1919 
1920 
1921             FT_TRACE4(( " blend\n" ));
1922 
1923             if ( num_results < 0 )
1924               goto Syntax_Error;
1925 
1926             if ( num_results * (FT_Int)num_designs > num_args )
1927               goto Stack_Underflow;
1928 
1929             /* since we currently don't handle interpolation of multiple */
1930             /* master fonts, return the `num_results' values of the      */
1931             /* first master                                              */
1932             args     -= num_results * ( num_designs - 1 );
1933             num_args -= num_results * ( num_designs - 1 );
1934           }
1935           break;
1936 
1937         case cff_op_dotsection:
1938           /* this operator is deprecated and ignored by the parser */
1939           FT_TRACE4(( " dotsection\n" ));
1940           break;
1941 
1942         case cff_op_closepath:
1943           /* this is an invalid Type 2 operator; however, there        */
1944           /* exist fonts which are incorrectly converted from probably */
1945           /* Type 1 to CFF, and some parsers seem to accept it         */
1946 
1947           FT_TRACE4(( " closepath (invalid op)\n" ));
1948 
1949           args = stack;
1950           break;
1951 
1952         case cff_op_hsbw:
1953           /* this is an invalid Type 2 operator; however, there        */
1954           /* exist fonts which are incorrectly converted from probably */
1955           /* Type 1 to CFF, and some parsers seem to accept it         */
1956 
1957           FT_TRACE4(( " hsbw (invalid op)\n" ));
1958 
1959           decoder->glyph_width =
1960             ADD_LONG( decoder->nominal_width, ( args[1] >> 16 ) );
1961 
1962           decoder->builder.left_bearing.x = args[0];
1963           decoder->builder.left_bearing.y = 0;
1964 
1965           x    = ADD_LONG( decoder->builder.pos_x, args[0] );
1966           y    = decoder->builder.pos_y;
1967           args = stack;
1968           break;
1969 
1970         case cff_op_sbw:
1971           /* this is an invalid Type 2 operator; however, there        */
1972           /* exist fonts which are incorrectly converted from probably */
1973           /* Type 1 to CFF, and some parsers seem to accept it         */
1974 
1975           FT_TRACE4(( " sbw (invalid op)\n" ));
1976 
1977           decoder->glyph_width =
1978             ADD_LONG( decoder->nominal_width, ( args[2] >> 16 ) );
1979 
1980           decoder->builder.left_bearing.x = args[0];
1981           decoder->builder.left_bearing.y = args[1];
1982 
1983           x    = ADD_LONG( decoder->builder.pos_x, args[0] );
1984           y    = ADD_LONG( decoder->builder.pos_y, args[1] );
1985           args = stack;
1986           break;
1987 
1988         case cff_op_setcurrentpoint:
1989           /* this is an invalid Type 2 operator; however, there        */
1990           /* exist fonts which are incorrectly converted from probably */
1991           /* Type 1 to CFF, and some parsers seem to accept it         */
1992 
1993           FT_TRACE4(( " setcurrentpoint (invalid op)\n" ));
1994 
1995           x    = ADD_LONG( decoder->builder.pos_x, args[0] );
1996           y    = ADD_LONG( decoder->builder.pos_y, args[1] );
1997           args = stack;
1998           break;
1999 
2000         case cff_op_callothersubr:
2001           /* this is an invalid Type 2 operator; however, there        */
2002           /* exist fonts which are incorrectly converted from probably */
2003           /* Type 1 to CFF, and some parsers seem to accept it         */
2004 
2005           FT_TRACE4(( " callothersubr (invalid op)\n" ));
2006 
2007           /* subsequent `pop' operands should add the arguments,       */
2008           /* this is the implementation described for `unknown' other  */
2009           /* subroutines in the Type1 spec.                            */
2010           /*                                                           */
2011           /* XXX Fix return arguments (see discussion below).          */
2012           args -= 2 + ( args[-2] >> 16 );
2013           if ( args < stack )
2014             goto Stack_Underflow;
2015           break;
2016 
2017         case cff_op_pop:
2018           /* this is an invalid Type 2 operator; however, there        */
2019           /* exist fonts which are incorrectly converted from probably */
2020           /* Type 1 to CFF, and some parsers seem to accept it         */
2021 
2022           FT_TRACE4(( " pop (invalid op)\n" ));
2023 
2024           /* XXX Increasing `args' is wrong: After a certain number of */
2025           /* `pop's we get a stack overflow.  Reason for doing it is   */
2026           /* code like this (actually found in a CFF font):            */
2027           /*                                                           */
2028           /*   17 1 3 callothersubr                                    */
2029           /*   pop                                                     */
2030           /*   callsubr                                                */
2031           /*                                                           */
2032           /* Since we handle `callothersubr' as a no-op, and           */
2033           /* `callsubr' needs at least one argument, `pop' can't be a  */
2034           /* no-op too as it basically should be.                      */
2035           /*                                                           */
2036           /* The right solution would be to provide real support for   */
2037           /* `callothersubr' as done in `t1decode.c', however, given   */
2038           /* the fact that CFF fonts with `pop' are invalid, it is     */
2039           /* questionable whether it is worth the time.                */
2040           args++;
2041           break;
2042 
2043         case cff_op_and:
2044           {
2045             FT_Fixed  cond = ( args[0] && args[1] );
2046 
2047 
2048             FT_TRACE4(( " and\n" ));
2049 
2050             args[0] = cond ? 0x10000L : 0;
2051             args++;
2052           }
2053           break;
2054 
2055         case cff_op_or:
2056           {
2057             FT_Fixed  cond = ( args[0] || args[1] );
2058 
2059 
2060             FT_TRACE4(( " or\n" ));
2061 
2062             args[0] = cond ? 0x10000L : 0;
2063             args++;
2064           }
2065           break;
2066 
2067         case cff_op_not:
2068           {
2069             FT_Fixed  cond = !args[0];
2070 
2071 
2072             FT_TRACE4(( " not\n" ));
2073 
2074             args[0] = cond ? 0x10000L : 0;
2075             args++;
2076           }
2077           break;
2078 
2079         case cff_op_eq:
2080           {
2081             FT_Fixed  cond = ( args[0] == args[1] );
2082 
2083 
2084             FT_TRACE4(( " eq\n" ));
2085 
2086             args[0] = cond ? 0x10000L : 0;
2087             args++;
2088           }
2089           break;
2090 
2091         case cff_op_ifelse:
2092           {
2093             FT_Fixed  cond = ( args[2] <= args[3] );
2094 
2095 
2096             FT_TRACE4(( " ifelse\n" ));
2097 
2098             if ( !cond )
2099               args[0] = args[1];
2100             args++;
2101           }
2102           break;
2103 
2104         case cff_op_callsubr:
2105           {
2106             FT_UInt  idx = (FT_UInt)( ( args[0] >> 16 ) +
2107                                       decoder->locals_bias );
2108 
2109 
2110             FT_TRACE4(( " callsubr (idx %d, entering level %d)\n",
2111                         idx,
2112                         zone - decoder->zones + 1 ));
2113 
2114             if ( idx >= decoder->num_locals )
2115             {
2116               FT_ERROR(( "cff_decoder_parse_charstrings:"
2117                          " invalid local subr index\n" ));
2118               goto Syntax_Error;
2119             }
2120 
2121             if ( zone - decoder->zones >= CFF_MAX_SUBRS_CALLS )
2122             {
2123               FT_ERROR(( "cff_decoder_parse_charstrings:"
2124                          " too many nested subrs\n" ));
2125               goto Syntax_Error;
2126             }
2127 
2128             zone->cursor = ip;  /* save current instruction pointer */
2129 
2130             zone++;
2131             zone->base   = decoder->locals[idx];
2132             zone->limit  = decoder->locals[idx + 1];
2133             zone->cursor = zone->base;
2134 
2135             if ( !zone->base || zone->limit == zone->base )
2136             {
2137               FT_ERROR(( "cff_decoder_parse_charstrings:"
2138                          " invoking empty subrs\n" ));
2139               goto Syntax_Error;
2140             }
2141 
2142             decoder->zone = zone;
2143             ip            = zone->base;
2144             limit         = zone->limit;
2145           }
2146           break;
2147 
2148         case cff_op_callgsubr:
2149           {
2150             FT_UInt  idx = (FT_UInt)( ( args[0] >> 16 ) +
2151                                       decoder->globals_bias );
2152 
2153 
2154             FT_TRACE4(( " callgsubr (idx %d, entering level %d)\n",
2155                         idx,
2156                         zone - decoder->zones + 1 ));
2157 
2158             if ( idx >= decoder->num_globals )
2159             {
2160               FT_ERROR(( "cff_decoder_parse_charstrings:"
2161                          " invalid global subr index\n" ));
2162               goto Syntax_Error;
2163             }
2164 
2165             if ( zone - decoder->zones >= CFF_MAX_SUBRS_CALLS )
2166             {
2167               FT_ERROR(( "cff_decoder_parse_charstrings:"
2168                          " too many nested subrs\n" ));
2169               goto Syntax_Error;
2170             }
2171 
2172             zone->cursor = ip;  /* save current instruction pointer */
2173 
2174             zone++;
2175             zone->base   = decoder->globals[idx];
2176             zone->limit  = decoder->globals[idx + 1];
2177             zone->cursor = zone->base;
2178 
2179             if ( !zone->base || zone->limit == zone->base )
2180             {
2181               FT_ERROR(( "cff_decoder_parse_charstrings:"
2182                          " invoking empty subrs\n" ));
2183               goto Syntax_Error;
2184             }
2185 
2186             decoder->zone = zone;
2187             ip            = zone->base;
2188             limit         = zone->limit;
2189           }
2190           break;
2191 
2192         case cff_op_return:
2193           FT_TRACE4(( " return (leaving level %d)\n",
2194                       decoder->zone - decoder->zones ));
2195 
2196           if ( decoder->zone <= decoder->zones )
2197           {
2198             FT_ERROR(( "cff_decoder_parse_charstrings:"
2199                        " unexpected return\n" ));
2200             goto Syntax_Error;
2201           }
2202 
2203           decoder->zone--;
2204           zone  = decoder->zone;
2205           ip    = zone->cursor;
2206           limit = zone->limit;
2207           break;
2208 
2209         default:
2210           FT_ERROR(( "Unimplemented opcode: %d", ip[-1] ));
2211 
2212           if ( ip[-1] == 12 )
2213             FT_ERROR(( " %d", ip[0] ));
2214           FT_ERROR(( "\n" ));
2215 
2216           return FT_THROW( Unimplemented_Feature );
2217         }
2218 
2219         decoder->top = args;
2220 
2221         if ( decoder->top - stack >= CFF_MAX_OPERANDS )
2222           goto Stack_Overflow;
2223 
2224       } /* general operator processing */
2225 
2226     } /* while ip < limit */
2227 
2228     FT_TRACE4(( "..end..\n\n" ));
2229 
2230   Fail:
2231     return error;
2232 
2233   MM_Error:
2234     FT_TRACE4(( "cff_decoder_parse_charstrings:"
2235                 " invalid opcode found in top DICT charstring\n"));
2236     return FT_THROW( Invalid_File_Format );
2237 
2238   Syntax_Error:
2239     FT_TRACE4(( "cff_decoder_parse_charstrings: syntax error\n" ));
2240     return FT_THROW( Invalid_File_Format );
2241 
2242   Stack_Underflow:
2243     FT_TRACE4(( "cff_decoder_parse_charstrings: stack underflow\n" ));
2244     return FT_THROW( Too_Few_Arguments );
2245 
2246   Stack_Overflow:
2247     FT_TRACE4(( "cff_decoder_parse_charstrings: stack overflow\n" ));
2248     return FT_THROW( Stack_Overflow );
2249   }
2250 
2251 #endif /* CFF_CONFIG_OPTION_OLD_ENGINE */
2252 
2253 
2254   /*************************************************************************/
2255   /*                                                                       */
2256   /* <Function>                                                            */
2257   /*    cff_decoder_init                                                   */
2258   /*                                                                       */
2259   /* <Description>                                                         */
2260   /*    Initializes a given glyph decoder.                                 */
2261   /*                                                                       */
2262   /* <InOut>                                                               */
2263   /*    decoder :: A pointer to the glyph builder to initialize.           */
2264   /*                                                                       */
2265   /* <Input>                                                               */
2266   /*    face      :: The current face object.                              */
2267   /*                                                                       */
2268   /*    size      :: The current size object.                              */
2269   /*                                                                       */
2270   /*    slot      :: The current glyph object.                             */
2271   /*                                                                       */
2272   /*    hinting   :: Whether hinting is active.                            */
2273   /*                                                                       */
2274   /*    hint_mode :: The hinting mode.                                     */
2275   /*                                                                       */
2276   FT_LOCAL_DEF( void )
cff_decoder_init(CFF_Decoder * decoder,TT_Face face,CFF_Size size,CFF_GlyphSlot slot,FT_Bool hinting,FT_Render_Mode hint_mode,CFF_Decoder_Get_Glyph_Callback get_callback,CFF_Decoder_Free_Glyph_Callback free_callback)2277   cff_decoder_init( CFF_Decoder*                     decoder,
2278                     TT_Face                          face,
2279                     CFF_Size                         size,
2280                     CFF_GlyphSlot                    slot,
2281                     FT_Bool                          hinting,
2282                     FT_Render_Mode                   hint_mode,
2283                     CFF_Decoder_Get_Glyph_Callback   get_callback,
2284                     CFF_Decoder_Free_Glyph_Callback  free_callback )
2285   {
2286     CFF_Font  cff = (CFF_Font)face->extra.data;
2287 
2288 
2289     /* clear everything */
2290     FT_ZERO( decoder );
2291 
2292     /* initialize builder */
2293     cff_builder_init( &decoder->builder, face, size, slot, hinting );
2294 
2295     /* initialize Type2 decoder */
2296     decoder->cff          = cff;
2297     decoder->num_globals  = cff->global_subrs_index.count;
2298     decoder->globals      = cff->global_subrs;
2299     decoder->globals_bias = cff_compute_bias(
2300                               cff->top_font.font_dict.charstring_type,
2301                               decoder->num_globals );
2302 
2303     decoder->hint_mode = hint_mode;
2304 
2305     decoder->get_glyph_callback  = get_callback;
2306     decoder->free_glyph_callback = free_callback;
2307   }
2308 
2309 
2310   /* this function is used to select the subfont */
2311   /* and the locals subrs array                  */
2312   FT_LOCAL_DEF( FT_Error )
cff_decoder_prepare(CFF_Decoder * decoder,CFF_Size size,FT_UInt glyph_index)2313   cff_decoder_prepare( CFF_Decoder*  decoder,
2314                        CFF_Size      size,
2315                        FT_UInt       glyph_index )
2316   {
2317     CFF_Builder  *builder = &decoder->builder;
2318     CFF_Font      cff     = (CFF_Font)builder->face->extra.data;
2319     CFF_SubFont   sub     = &cff->top_font;
2320     FT_Error      error   = FT_Err_Ok;
2321 
2322     FT_Service_CFFLoad  cffload = (FT_Service_CFFLoad)cff->cffload;
2323 
2324 
2325     /* manage CID fonts */
2326     if ( cff->num_subfonts )
2327     {
2328       FT_Byte  fd_index = cffload->fd_select_get( &cff->fd_select,
2329                                                   glyph_index );
2330 
2331 
2332       if ( fd_index >= cff->num_subfonts )
2333       {
2334         FT_TRACE4(( "cff_decoder_prepare: invalid CID subfont index\n" ));
2335         error = FT_THROW( Invalid_File_Format );
2336         goto Exit;
2337       }
2338 
2339       FT_TRACE3(( "  in subfont %d:\n", fd_index ));
2340 
2341       sub = cff->subfonts[fd_index];
2342 
2343       if ( builder->hints_funcs && size )
2344       {
2345         FT_Size       ftsize   = FT_SIZE( size );
2346         CFF_Internal  internal = (CFF_Internal)ftsize->internal->module_data;
2347 
2348 
2349         /* for CFFs without subfonts, this value has already been set */
2350         builder->hints_globals = (void *)internal->subfonts[fd_index];
2351       }
2352     }
2353 
2354     decoder->num_locals  = sub->local_subrs_index.count;
2355     decoder->locals      = sub->local_subrs;
2356     decoder->locals_bias = cff_compute_bias(
2357                              decoder->cff->top_font.font_dict.charstring_type,
2358                              decoder->num_locals );
2359 
2360     decoder->glyph_width   = sub->private_dict.default_width;
2361     decoder->nominal_width = sub->private_dict.nominal_width;
2362 
2363     decoder->current_subfont = sub;
2364 
2365   Exit:
2366     return error;
2367   }
2368 
2369 
2370 /* END */
2371