xref: /aosp_15_r20/external/freetype/src/cid/cidgload.c (revision 63949dbd25bcc50c4e1178497ff9e9574d44fc5a)
1 /****************************************************************************
2  *
3  * cidgload.c
4  *
5  *   CID-keyed Type1 Glyph Loader (body).
6  *
7  * Copyright (C) 1996-2023 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 "cidload.h"
20 #include "cidgload.h"
21 #include <freetype/internal/ftdebug.h>
22 #include <freetype/internal/ftstream.h>
23 #include <freetype/ftoutln.h>
24 #include <freetype/internal/ftcalc.h>
25 
26 #include <freetype/internal/psaux.h>
27 #include <freetype/internal/cfftypes.h>
28 #include <freetype/ftdriver.h>
29 
30 #include "ciderrs.h"
31 
32 
33   /**************************************************************************
34    *
35    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
36    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
37    * messages during execution.
38    */
39 #undef  FT_COMPONENT
40 #define FT_COMPONENT  cidgload
41 
42 
43   /*
44    * A helper function to compute FD number (`fd_select`), the offset to the
45    * head of the glyph data (`off1`), and the offset to the and of the glyph
46    * data (`off2`).
47    *
48    * The number how many times `cid_get_offset` is invoked can be controlled
49    * by the number of non-NULL arguments.  If `fd_select` is non-NULL but
50    * `off1` and `off2` are NULL, `cid_get_offset` is invoked only for
51    * `fd_select`; `off1` and `off2` are not validated.
52    *
53    */
54   FT_LOCAL_DEF( FT_Error )
cid_compute_fd_and_offsets(CID_Face face,FT_UInt glyph_index,FT_ULong * fd_select_p,FT_ULong * off1_p,FT_ULong * off2_p)55   cid_compute_fd_and_offsets( CID_Face   face,
56                               FT_UInt    glyph_index,
57                               FT_ULong*  fd_select_p,
58                               FT_ULong*  off1_p,
59                               FT_ULong*  off2_p )
60   {
61     FT_Error  error = FT_Err_Ok;
62 
63     CID_FaceInfo  cid       = &face->cid;
64     FT_Stream     stream    =  face->cid_stream;
65     FT_UInt       entry_len = cid->fd_bytes + cid->gd_bytes;
66 
67     FT_Byte*  p;
68     FT_Bool   need_frame_exit = 0;
69     FT_ULong  fd_select, off1, off2;
70 
71 
72     /* For ordinary fonts, read the CID font dictionary index */
73     /* and charstring offset from the CIDMap.                 */
74 
75     if ( FT_STREAM_SEEK( cid->data_offset + cid->cidmap_offset +
76                          glyph_index * entry_len )               ||
77          FT_FRAME_ENTER( 2 * entry_len )                         )
78       goto Exit;
79 
80     need_frame_exit = 1;
81 
82     p         = (FT_Byte*)stream->cursor;
83     fd_select = cid_get_offset( &p, cid->fd_bytes );
84     off1      = cid_get_offset( &p, cid->gd_bytes );
85 
86     p    += cid->fd_bytes;
87     off2  = cid_get_offset( &p, cid->gd_bytes );
88 
89     if ( fd_select_p )
90       *fd_select_p = fd_select;
91     if ( off1_p )
92       *off1_p = off1;
93     if ( off2_p )
94       *off2_p = off2;
95 
96     if ( fd_select >= cid->num_dicts )
97     {
98       /*
99        * fd_select == 0xFF is often used to indicate that the CID
100        * has no charstring to be rendered, similar to GID = 0xFFFF
101        * in TrueType fonts.
102        */
103       if ( ( cid->fd_bytes == 1 && fd_select == 0xFFU   ) ||
104            ( cid->fd_bytes == 2 && fd_select == 0xFFFFU ) )
105       {
106         FT_TRACE1(( "cid_load_glyph: fail for glyph index %d:\n",
107                     glyph_index ));
108         FT_TRACE1(( "                FD number %ld is the maximum\n",
109                     fd_select ));
110         FT_TRACE1(( "                integer fitting into %d byte%s\n",
111                     cid->fd_bytes, cid->fd_bytes == 1 ? "" : "s" ));
112       }
113       else
114       {
115         FT_TRACE0(( "cid_load_glyph: fail for glyph index %d:\n",
116                     glyph_index ));
117         FT_TRACE0(( "                FD number %ld is larger\n",
118                     fd_select ));
119         FT_TRACE0(( "                than number of dictionaries (%d)\n",
120                     cid->num_dicts ));
121       }
122 
123       error = FT_THROW( Invalid_Offset );
124       goto Exit;
125     }
126     else if ( off2 > stream->size )
127     {
128       FT_TRACE0(( "cid_load_glyph: fail for glyph index %d:\n",
129                   glyph_index ));
130       FT_TRACE0(( "               end of the glyph data\n" ));
131       FT_TRACE0(( "               is beyond the data stream\n" ));
132 
133       error = FT_THROW( Invalid_Offset );
134       goto Exit;
135     }
136     else if ( off1 > off2 )
137     {
138       FT_TRACE0(( "cid_load_glyph: fail for glyph index %d:\n",
139                   glyph_index ));
140       FT_TRACE0(( "                the end position of glyph data\n" ));
141       FT_TRACE0(( "                is set before the start position\n" ));
142 
143       error = FT_THROW( Invalid_Offset );
144     }
145 
146     Exit:
147       if ( need_frame_exit )
148         FT_FRAME_EXIT();
149 
150     return error;
151   }
152 
153 
154   FT_CALLBACK_DEF( FT_Error )
cid_load_glyph(T1_Decoder decoder,FT_UInt glyph_index)155   cid_load_glyph( T1_Decoder  decoder,
156                   FT_UInt     glyph_index )
157   {
158     CID_Face       face = (CID_Face)decoder->builder.face;
159     CID_FaceInfo   cid  = &face->cid;
160     FT_Byte*       p;
161     FT_ULong       fd_select;
162     FT_Stream      stream       = face->cid_stream;
163     FT_Error       error        = FT_Err_Ok;
164     FT_Byte*       charstring   = NULL;
165     FT_Memory      memory       = face->root.memory;
166     FT_ULong       glyph_length = 0;
167     PSAux_Service  psaux        = (PSAux_Service)face->psaux;
168 
169     FT_Bool  force_scaling = FALSE;
170 
171 #ifdef FT_CONFIG_OPTION_INCREMENTAL
172     FT_Incremental_InterfaceRec  *inc =
173                                    face->root.internal->incremental_interface;
174 #endif
175 
176 
177     FT_TRACE1(( "cid_load_glyph: glyph index %u\n", glyph_index ));
178 
179 #ifdef FT_CONFIG_OPTION_INCREMENTAL
180 
181     /* For incremental fonts get the character data using */
182     /* the callback function.                             */
183     if ( inc )
184     {
185       FT_Data  glyph_data;
186 
187 
188       error = inc->funcs->get_glyph_data( inc->object,
189                                           glyph_index, &glyph_data );
190       if ( error || glyph_data.length < cid->fd_bytes )
191         goto Exit;
192 
193       p         = (FT_Byte*)glyph_data.pointer;
194       fd_select = cid_get_offset( &p, cid->fd_bytes );
195 
196       glyph_length = glyph_data.length - cid->fd_bytes;
197 
198       if ( !FT_QALLOC( charstring, glyph_length ) )
199         FT_MEM_COPY( charstring, glyph_data.pointer + cid->fd_bytes,
200                      glyph_length );
201 
202       inc->funcs->free_glyph_data( inc->object, &glyph_data );
203 
204       if ( error )
205         goto Exit;
206     }
207 
208     else
209 
210 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
211     {
212       FT_ULong  off1, off2;
213 
214 
215       error = cid_compute_fd_and_offsets( face, glyph_index,
216                                           &fd_select, &off1, &off2 );
217       if ( error )
218         goto Exit;
219 
220       glyph_length = off2 - off1;
221 
222       if ( glyph_length == 0                             ||
223            FT_QALLOC( charstring, glyph_length )         ||
224            FT_STREAM_READ_AT( cid->data_offset + off1,
225                               charstring, glyph_length ) )
226         goto Exit;
227     }
228 
229     /* Now set up the subrs array and parse the charstrings. */
230     {
231       CID_FaceDict  dict;
232       CID_Subrs     cid_subrs = face->subrs + fd_select;
233       FT_UInt       cs_offset;
234 
235 
236       /* Set up subrs */
237       decoder->num_subrs  = cid_subrs->num_subrs;
238       decoder->subrs      = cid_subrs->code;
239       decoder->subrs_len  = 0;
240       decoder->subrs_hash = NULL;
241 
242       /* Set up font matrix */
243       dict                 = cid->font_dicts + fd_select;
244 
245       decoder->font_matrix = dict->font_matrix;
246       decoder->font_offset = dict->font_offset;
247       decoder->lenIV       = dict->private_dict.lenIV;
248 
249       /* Decode the charstring. */
250 
251       /* Adjustment for seed bytes. */
252       cs_offset = decoder->lenIV >= 0 ? (FT_UInt)decoder->lenIV : 0;
253       if ( cs_offset > glyph_length )
254       {
255         FT_TRACE0(( "cid_load_glyph: fail for glyph_index=%d, "
256                     "offset to the charstring is beyond glyph length\n",
257                     glyph_index ));
258         error = FT_THROW( Invalid_Offset );
259         goto Exit;
260       }
261 
262       /* Decrypt only if lenIV >= 0. */
263       if ( decoder->lenIV >= 0 )
264         psaux->t1_decrypt( charstring, glyph_length, 4330 );
265 
266       /* choose which renderer to use */
267 #ifdef T1_CONFIG_OPTION_OLD_ENGINE
268       if ( ( (PS_Driver)FT_FACE_DRIVER( face ) )->hinting_engine ==
269                FT_HINTING_FREETYPE                                  ||
270            decoder->builder.metrics_only                            )
271         error = psaux->t1_decoder_funcs->parse_charstrings_old(
272                   decoder,
273                   charstring + cs_offset,
274                   glyph_length - cs_offset );
275 #else
276       if ( decoder->builder.metrics_only )
277         error = psaux->t1_decoder_funcs->parse_metrics(
278                   decoder,
279                   charstring + cs_offset,
280                   glyph_length - cs_offset );
281 #endif
282       else
283       {
284         PS_Decoder      psdecoder;
285         CFF_SubFontRec  subfont;
286 
287 
288         psaux->ps_decoder_init( &psdecoder, decoder, TRUE );
289 
290         psaux->t1_make_subfont( FT_FACE( face ),
291                                 &dict->private_dict,
292                                 &subfont );
293         psdecoder.current_subfont = &subfont;
294 
295         error = psaux->t1_decoder_funcs->parse_charstrings(
296                   &psdecoder,
297                   charstring + cs_offset,
298                   glyph_length - cs_offset );
299 
300         /* Adobe's engine uses 16.16 numbers everywhere;              */
301         /* as a consequence, glyphs larger than 2000ppem get rejected */
302         if ( FT_ERR_EQ( error, Glyph_Too_Big ) )
303         {
304           /* this time, we retry unhinted and scale up the glyph later on */
305           /* (the engine uses and sets the hardcoded value 0x10000 / 64 = */
306           /* 0x400 for both `x_scale' and `y_scale' in this case)         */
307           ((CID_GlyphSlot)decoder->builder.glyph)->hint = FALSE;
308 
309           force_scaling = TRUE;
310 
311           error = psaux->t1_decoder_funcs->parse_charstrings(
312                     &psdecoder,
313                     charstring + cs_offset,
314                     glyph_length - cs_offset );
315         }
316       }
317     }
318 
319 #ifdef FT_CONFIG_OPTION_INCREMENTAL
320 
321     /* Incremental fonts can optionally override the metrics. */
322     if ( !error && inc && inc->funcs->get_glyph_metrics )
323     {
324       FT_Incremental_MetricsRec  metrics;
325 
326 
327       metrics.bearing_x = FIXED_TO_INT( decoder->builder.left_bearing.x );
328       metrics.bearing_y = 0;
329       metrics.advance   = FIXED_TO_INT( decoder->builder.advance.x );
330       metrics.advance_v = FIXED_TO_INT( decoder->builder.advance.y );
331 
332       error = inc->funcs->get_glyph_metrics( inc->object,
333                                              glyph_index, FALSE, &metrics );
334 
335       decoder->builder.left_bearing.x = INT_TO_FIXED( metrics.bearing_x );
336       decoder->builder.advance.x      = INT_TO_FIXED( metrics.advance );
337       decoder->builder.advance.y      = INT_TO_FIXED( metrics.advance_v );
338     }
339 
340 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
341 
342   Exit:
343     FT_FREE( charstring );
344 
345     ((CID_GlyphSlot)decoder->builder.glyph)->scaled = force_scaling;
346 
347     return error;
348   }
349 
350 
351 #if 0
352 
353 
354   /*************************************************************************/
355   /*************************************************************************/
356   /*************************************************************************/
357   /**********                                                      *********/
358   /**********                                                      *********/
359   /**********            COMPUTE THE MAXIMUM ADVANCE WIDTH         *********/
360   /**********                                                      *********/
361   /**********    The following code is in charge of computing      *********/
362   /**********    the maximum advance width of the font.  It        *********/
363   /**********    quickly processes each glyph charstring to        *********/
364   /**********    extract the value from either a `sbw' or `seac'   *********/
365   /**********    operator.                                         *********/
366   /**********                                                      *********/
367   /*************************************************************************/
368   /*************************************************************************/
369   /*************************************************************************/
370 
371 
372   FT_LOCAL_DEF( FT_Error )
373   cid_face_compute_max_advance( CID_Face  face,
374                                 FT_Int*   max_advance )
375   {
376     FT_Error       error;
377     T1_DecoderRec  decoder;
378     FT_Int         glyph_index;
379 
380     PSAux_Service  psaux = (PSAux_Service)face->psaux;
381 
382 
383     *max_advance = 0;
384 
385     /* Initialize load decoder */
386     error = psaux->t1_decoder_funcs->init( &decoder,
387                                            (FT_Face)face,
388                                            0, /* size       */
389                                            0, /* glyph slot */
390                                            0, /* glyph names! XXX */
391                                            0, /* blend == 0 */
392                                            0, /* hinting == 0 */
393                                            cid_load_glyph );
394     if ( error )
395       return error;
396 
397     /* TODO: initialize decoder.len_buildchar and decoder.buildchar */
398     /*       if we ever support CID-keyed multiple master fonts     */
399 
400     decoder.builder.metrics_only = 1;
401     decoder.builder.load_points  = 0;
402 
403     /* for each glyph, parse the glyph charstring and extract */
404     /* the advance width                                      */
405     for ( glyph_index = 0; glyph_index < face->root.num_glyphs;
406           glyph_index++ )
407     {
408       /* now get load the unscaled outline */
409       error = cid_load_glyph( &decoder, glyph_index );
410       /* ignore the error if one occurred - skip to next glyph */
411     }
412 
413     *max_advance = FIXED_TO_INT( decoder.builder.advance.x );
414 
415     psaux->t1_decoder_funcs->done( &decoder );
416 
417     return FT_Err_Ok;
418   }
419 
420 
421 #endif /* 0 */
422 
423 
424   FT_LOCAL_DEF( FT_Error )
cid_slot_load_glyph(FT_GlyphSlot cidglyph,FT_Size cidsize,FT_UInt glyph_index,FT_Int32 load_flags)425   cid_slot_load_glyph( FT_GlyphSlot  cidglyph,      /* CID_GlyphSlot */
426                        FT_Size       cidsize,       /* CID_Size      */
427                        FT_UInt       glyph_index,
428                        FT_Int32      load_flags )
429   {
430     CID_GlyphSlot  glyph = (CID_GlyphSlot)cidglyph;
431     FT_Error       error;
432     T1_DecoderRec  decoder;
433     CID_Face       face = (CID_Face)cidglyph->face;
434     FT_Bool        hinting;
435     FT_Bool        scaled;
436 
437     PSAux_Service  psaux = (PSAux_Service)face->psaux;
438     FT_Matrix      font_matrix;
439     FT_Vector      font_offset;
440     FT_Bool        must_finish_decoder = FALSE;
441 
442 
443     if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
444     {
445       error = FT_THROW( Invalid_Argument );
446       goto Exit;
447     }
448 
449     if ( load_flags & FT_LOAD_NO_RECURSE )
450       load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING;
451 
452     glyph->x_scale = cidsize->metrics.x_scale;
453     glyph->y_scale = cidsize->metrics.y_scale;
454 
455     cidglyph->outline.n_points   = 0;
456     cidglyph->outline.n_contours = 0;
457 
458     hinting = FT_BOOL( ( load_flags & FT_LOAD_NO_SCALE   ) == 0 &&
459                        ( load_flags & FT_LOAD_NO_HINTING ) == 0 );
460     scaled  = FT_BOOL( ( load_flags & FT_LOAD_NO_SCALE   ) == 0 );
461 
462     glyph->hint      = hinting;
463     glyph->scaled    = scaled;
464     cidglyph->format = FT_GLYPH_FORMAT_OUTLINE;
465 
466     error = psaux->t1_decoder_funcs->init( &decoder,
467                                            cidglyph->face,
468                                            cidsize,
469                                            cidglyph,
470                                            0, /* glyph names -- XXX */
471                                            0, /* blend == 0 */
472                                            hinting,
473                                            FT_LOAD_TARGET_MODE( load_flags ),
474                                            cid_load_glyph );
475     if ( error )
476       goto Exit;
477 
478     /* TODO: initialize decoder.len_buildchar and decoder.buildchar */
479     /*       if we ever support CID-keyed multiple master fonts     */
480 
481     must_finish_decoder = TRUE;
482 
483     /* set up the decoder */
484     decoder.builder.no_recurse = FT_BOOL( load_flags & FT_LOAD_NO_RECURSE );
485 
486     error = cid_load_glyph( &decoder, glyph_index );
487     if ( error )
488       goto Exit;
489 
490     /* copy flags back for forced scaling */
491     hinting = glyph->hint;
492     scaled  = glyph->scaled;
493 
494     font_matrix = decoder.font_matrix;
495     font_offset = decoder.font_offset;
496 
497     /* save new glyph tables */
498     psaux->t1_decoder_funcs->done( &decoder );
499 
500     must_finish_decoder = FALSE;
501 
502     /* now set the metrics -- this is rather simple, as    */
503     /* the left side bearing is the xMin, and the top side */
504     /* bearing the yMax                                    */
505     cidglyph->outline.flags &= FT_OUTLINE_OWNER;
506     cidglyph->outline.flags |= FT_OUTLINE_REVERSE_FILL;
507 
508     /* for composite glyphs, return only left side bearing and */
509     /* advance width                                           */
510     if ( load_flags & FT_LOAD_NO_RECURSE )
511     {
512       FT_Slot_Internal  internal = cidglyph->internal;
513 
514 
515       cidglyph->metrics.horiBearingX =
516         FIXED_TO_INT( decoder.builder.left_bearing.x );
517       cidglyph->metrics.horiAdvance =
518         FIXED_TO_INT( decoder.builder.advance.x );
519 
520       internal->glyph_matrix      = font_matrix;
521       internal->glyph_delta       = font_offset;
522       internal->glyph_transformed = 1;
523     }
524     else
525     {
526       FT_BBox            cbox;
527       FT_Glyph_Metrics*  metrics = &cidglyph->metrics;
528 
529 
530       /* copy the _unscaled_ advance width */
531       metrics->horiAdvance =
532         FIXED_TO_INT( decoder.builder.advance.x );
533       cidglyph->linearHoriAdvance =
534         FIXED_TO_INT( decoder.builder.advance.x );
535       cidglyph->internal->glyph_transformed = 0;
536 
537       /* make up vertical ones */
538       metrics->vertAdvance        = ( face->cid.font_bbox.yMax -
539                                       face->cid.font_bbox.yMin ) >> 16;
540       cidglyph->linearVertAdvance = metrics->vertAdvance;
541 
542       cidglyph->format            = FT_GLYPH_FORMAT_OUTLINE;
543 
544       if ( cidsize->metrics.y_ppem < 24 )
545         cidglyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;
546 
547       /* apply the font matrix, if any */
548       if ( font_matrix.xx != 0x10000L || font_matrix.yy != 0x10000L ||
549            font_matrix.xy != 0        || font_matrix.yx != 0        )
550       {
551         FT_Outline_Transform( &cidglyph->outline, &font_matrix );
552 
553         metrics->horiAdvance = FT_MulFix( metrics->horiAdvance,
554                                           font_matrix.xx );
555         metrics->vertAdvance = FT_MulFix( metrics->vertAdvance,
556                                           font_matrix.yy );
557       }
558 
559       if ( font_offset.x || font_offset.y )
560       {
561         FT_Outline_Translate( &cidglyph->outline,
562                               font_offset.x,
563                               font_offset.y );
564 
565         metrics->horiAdvance += font_offset.x;
566         metrics->vertAdvance += font_offset.y;
567       }
568 
569       if ( ( load_flags & FT_LOAD_NO_SCALE ) == 0 || scaled )
570       {
571         /* scale the outline and the metrics */
572         FT_Int       n;
573         FT_Outline*  cur = decoder.builder.base;
574         FT_Vector*   vec = cur->points;
575         FT_Fixed     x_scale = glyph->x_scale;
576         FT_Fixed     y_scale = glyph->y_scale;
577 
578 
579         /* First of all, scale the points */
580         if ( !hinting || !decoder.builder.hints_funcs )
581           for ( n = cur->n_points; n > 0; n--, vec++ )
582           {
583             vec->x = FT_MulFix( vec->x, x_scale );
584             vec->y = FT_MulFix( vec->y, y_scale );
585           }
586 
587         /* Then scale the metrics */
588         metrics->horiAdvance = FT_MulFix( metrics->horiAdvance, x_scale );
589         metrics->vertAdvance = FT_MulFix( metrics->vertAdvance, y_scale );
590       }
591 
592       /* compute the other metrics */
593       FT_Outline_Get_CBox( &cidglyph->outline, &cbox );
594 
595       metrics->width  = cbox.xMax - cbox.xMin;
596       metrics->height = cbox.yMax - cbox.yMin;
597 
598       metrics->horiBearingX = cbox.xMin;
599       metrics->horiBearingY = cbox.yMax;
600 
601       if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
602       {
603         /* make up vertical ones */
604         ft_synthesize_vertical_metrics( metrics,
605                                         metrics->vertAdvance );
606       }
607     }
608 
609   Exit:
610 
611     if ( must_finish_decoder )
612       psaux->t1_decoder_funcs->done( &decoder );
613 
614     return error;
615   }
616 
617 
618 /* END */
619