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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   FT_CALLBACK_DEF( FT_Error )
cid_load_glyph(T1_Decoder decoder,FT_UInt glyph_index)44   cid_load_glyph( T1_Decoder  decoder,
45                   FT_UInt     glyph_index )
46   {
47     CID_Face       face = (CID_Face)decoder->builder.face;
48     CID_FaceInfo   cid  = &face->cid;
49     FT_Byte*       p;
50     FT_ULong       fd_select;
51     FT_Stream      stream       = face->cid_stream;
52     FT_Error       error        = FT_Err_Ok;
53     FT_Byte*       charstring   = NULL;
54     FT_Memory      memory       = face->root.memory;
55     FT_ULong       glyph_length = 0;
56     PSAux_Service  psaux        = (PSAux_Service)face->psaux;
57 
58     FT_Bool  force_scaling = FALSE;
59 
60 #ifdef FT_CONFIG_OPTION_INCREMENTAL
61     FT_Incremental_InterfaceRec  *inc =
62                                    face->root.internal->incremental_interface;
63 #endif
64 
65 
66     FT_TRACE1(( "cid_load_glyph: glyph index %u\n", glyph_index ));
67 
68 #ifdef FT_CONFIG_OPTION_INCREMENTAL
69 
70     /* For incremental fonts get the character data using */
71     /* the callback function.                             */
72     if ( inc )
73     {
74       FT_Data  glyph_data;
75 
76 
77       error = inc->funcs->get_glyph_data( inc->object,
78                                           glyph_index, &glyph_data );
79       if ( error || glyph_data.length < cid->fd_bytes )
80         goto Exit;
81 
82       p         = (FT_Byte*)glyph_data.pointer;
83       fd_select = cid_get_offset( &p, cid->fd_bytes );
84 
85       glyph_length = glyph_data.length - cid->fd_bytes;
86 
87       if ( !FT_QALLOC( charstring, glyph_length ) )
88         FT_MEM_COPY( charstring, glyph_data.pointer + cid->fd_bytes,
89                      glyph_length );
90 
91       inc->funcs->free_glyph_data( inc->object, &glyph_data );
92 
93       if ( error )
94         goto Exit;
95     }
96 
97     else
98 
99 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
100 
101     /* For ordinary fonts read the CID font dictionary index */
102     /* and charstring offset from the CIDMap.                */
103     {
104       FT_UInt   entry_len = cid->fd_bytes + cid->gd_bytes;
105       FT_ULong  off1, off2;
106 
107 
108       if ( FT_STREAM_SEEK( cid->data_offset + cid->cidmap_offset +
109                            glyph_index * entry_len )               ||
110            FT_FRAME_ENTER( 2 * entry_len )                         )
111         goto Exit;
112 
113       p         = (FT_Byte*)stream->cursor;
114       fd_select = cid_get_offset( &p, cid->fd_bytes );
115       off1      = cid_get_offset( &p, cid->gd_bytes );
116       p        += cid->fd_bytes;
117       off2      = cid_get_offset( &p, cid->gd_bytes );
118       FT_FRAME_EXIT();
119 
120       if ( fd_select >= cid->num_dicts ||
121            off2 > stream->size         ||
122            off1 > off2                 )
123       {
124         FT_TRACE0(( "cid_load_glyph: invalid glyph stream offsets\n" ));
125         error = FT_THROW( Invalid_Offset );
126         goto Exit;
127       }
128 
129       glyph_length = off2 - off1;
130 
131       if ( glyph_length == 0                             ||
132            FT_QALLOC( charstring, glyph_length )         ||
133            FT_STREAM_READ_AT( cid->data_offset + off1,
134                               charstring, glyph_length ) )
135         goto Exit;
136     }
137 
138     /* Now set up the subrs array and parse the charstrings. */
139     {
140       CID_FaceDict  dict;
141       CID_Subrs     cid_subrs = face->subrs + fd_select;
142       FT_UInt       cs_offset;
143 
144 
145       /* Set up subrs */
146       decoder->num_subrs  = cid_subrs->num_subrs;
147       decoder->subrs      = cid_subrs->code;
148       decoder->subrs_len  = 0;
149       decoder->subrs_hash = NULL;
150 
151       /* Set up font matrix */
152       dict                 = cid->font_dicts + fd_select;
153 
154       decoder->font_matrix = dict->font_matrix;
155       decoder->font_offset = dict->font_offset;
156       decoder->lenIV       = dict->private_dict.lenIV;
157 
158       /* Decode the charstring. */
159 
160       /* Adjustment for seed bytes. */
161       cs_offset = decoder->lenIV >= 0 ? (FT_UInt)decoder->lenIV : 0;
162       if ( cs_offset > glyph_length )
163       {
164         FT_TRACE0(( "cid_load_glyph: invalid glyph stream offsets\n" ));
165         error = FT_THROW( Invalid_Offset );
166         goto Exit;
167       }
168 
169       /* Decrypt only if lenIV >= 0. */
170       if ( decoder->lenIV >= 0 )
171         psaux->t1_decrypt( charstring, glyph_length, 4330 );
172 
173       /* choose which renderer to use */
174 #ifdef T1_CONFIG_OPTION_OLD_ENGINE
175       if ( ( (PS_Driver)FT_FACE_DRIVER( face ) )->hinting_engine ==
176                FT_HINTING_FREETYPE                                  ||
177            decoder->builder.metrics_only                            )
178         error = psaux->t1_decoder_funcs->parse_charstrings_old(
179                   decoder,
180                   charstring + cs_offset,
181                   glyph_length - cs_offset );
182 #else
183       if ( decoder->builder.metrics_only )
184         error = psaux->t1_decoder_funcs->parse_metrics(
185                   decoder,
186                   charstring + cs_offset,
187                   glyph_length - cs_offset );
188 #endif
189       else
190       {
191         PS_Decoder      psdecoder;
192         CFF_SubFontRec  subfont;
193 
194 
195         psaux->ps_decoder_init( &psdecoder, decoder, TRUE );
196 
197         psaux->t1_make_subfont( FT_FACE( face ),
198                                 &dict->private_dict,
199                                 &subfont );
200         psdecoder.current_subfont = &subfont;
201 
202         error = psaux->t1_decoder_funcs->parse_charstrings(
203                   &psdecoder,
204                   charstring + cs_offset,
205                   glyph_length - cs_offset );
206 
207         /* Adobe's engine uses 16.16 numbers everywhere;              */
208         /* as a consequence, glyphs larger than 2000ppem get rejected */
209         if ( FT_ERR_EQ( error, Glyph_Too_Big ) )
210         {
211           /* this time, we retry unhinted and scale up the glyph later on */
212           /* (the engine uses and sets the hardcoded value 0x10000 / 64 = */
213           /* 0x400 for both `x_scale' and `y_scale' in this case)         */
214           ((CID_GlyphSlot)decoder->builder.glyph)->hint = FALSE;
215 
216           force_scaling = TRUE;
217 
218           error = psaux->t1_decoder_funcs->parse_charstrings(
219                     &psdecoder,
220                     charstring + cs_offset,
221                     glyph_length - cs_offset );
222         }
223       }
224     }
225 
226 #ifdef FT_CONFIG_OPTION_INCREMENTAL
227 
228     /* Incremental fonts can optionally override the metrics. */
229     if ( !error && inc && inc->funcs->get_glyph_metrics )
230     {
231       FT_Incremental_MetricsRec  metrics;
232 
233 
234       metrics.bearing_x = FIXED_TO_INT( decoder->builder.left_bearing.x );
235       metrics.bearing_y = 0;
236       metrics.advance   = FIXED_TO_INT( decoder->builder.advance.x );
237       metrics.advance_v = FIXED_TO_INT( decoder->builder.advance.y );
238 
239       error = inc->funcs->get_glyph_metrics( inc->object,
240                                              glyph_index, FALSE, &metrics );
241 
242       decoder->builder.left_bearing.x = INT_TO_FIXED( metrics.bearing_x );
243       decoder->builder.advance.x      = INT_TO_FIXED( metrics.advance );
244       decoder->builder.advance.y      = INT_TO_FIXED( metrics.advance_v );
245     }
246 
247 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
248 
249   Exit:
250     FT_FREE( charstring );
251 
252     ((CID_GlyphSlot)decoder->builder.glyph)->scaled = force_scaling;
253 
254     return error;
255   }
256 
257 
258 #if 0
259 
260 
261   /*************************************************************************/
262   /*************************************************************************/
263   /*************************************************************************/
264   /**********                                                      *********/
265   /**********                                                      *********/
266   /**********            COMPUTE THE MAXIMUM ADVANCE WIDTH         *********/
267   /**********                                                      *********/
268   /**********    The following code is in charge of computing      *********/
269   /**********    the maximum advance width of the font.  It        *********/
270   /**********    quickly processes each glyph charstring to        *********/
271   /**********    extract the value from either a `sbw' or `seac'   *********/
272   /**********    operator.                                         *********/
273   /**********                                                      *********/
274   /*************************************************************************/
275   /*************************************************************************/
276   /*************************************************************************/
277 
278 
279   FT_LOCAL_DEF( FT_Error )
280   cid_face_compute_max_advance( CID_Face  face,
281                                 FT_Int*   max_advance )
282   {
283     FT_Error       error;
284     T1_DecoderRec  decoder;
285     FT_Int         glyph_index;
286 
287     PSAux_Service  psaux = (PSAux_Service)face->psaux;
288 
289 
290     *max_advance = 0;
291 
292     /* Initialize load decoder */
293     error = psaux->t1_decoder_funcs->init( &decoder,
294                                            (FT_Face)face,
295                                            0, /* size       */
296                                            0, /* glyph slot */
297                                            0, /* glyph names! XXX */
298                                            0, /* blend == 0 */
299                                            0, /* hinting == 0 */
300                                            cid_load_glyph );
301     if ( error )
302       return error;
303 
304     /* TODO: initialize decoder.len_buildchar and decoder.buildchar */
305     /*       if we ever support CID-keyed multiple master fonts     */
306 
307     decoder.builder.metrics_only = 1;
308     decoder.builder.load_points  = 0;
309 
310     /* for each glyph, parse the glyph charstring and extract */
311     /* the advance width                                      */
312     for ( glyph_index = 0; glyph_index < face->root.num_glyphs;
313           glyph_index++ )
314     {
315       /* now get load the unscaled outline */
316       error = cid_load_glyph( &decoder, glyph_index );
317       /* ignore the error if one occurred - skip to next glyph */
318     }
319 
320     *max_advance = FIXED_TO_INT( decoder.builder.advance.x );
321 
322     psaux->t1_decoder_funcs->done( &decoder );
323 
324     return FT_Err_Ok;
325   }
326 
327 
328 #endif /* 0 */
329 
330 
331   FT_LOCAL_DEF( FT_Error )
cid_slot_load_glyph(FT_GlyphSlot cidglyph,FT_Size cidsize,FT_UInt glyph_index,FT_Int32 load_flags)332   cid_slot_load_glyph( FT_GlyphSlot  cidglyph,      /* CID_GlyphSlot */
333                        FT_Size       cidsize,       /* CID_Size      */
334                        FT_UInt       glyph_index,
335                        FT_Int32      load_flags )
336   {
337     CID_GlyphSlot  glyph = (CID_GlyphSlot)cidglyph;
338     FT_Error       error;
339     T1_DecoderRec  decoder;
340     CID_Face       face = (CID_Face)cidglyph->face;
341     FT_Bool        hinting;
342     FT_Bool        scaled;
343 
344     PSAux_Service  psaux = (PSAux_Service)face->psaux;
345     FT_Matrix      font_matrix;
346     FT_Vector      font_offset;
347     FT_Bool        must_finish_decoder = FALSE;
348 
349 
350     if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
351     {
352       error = FT_THROW( Invalid_Argument );
353       goto Exit;
354     }
355 
356     if ( load_flags & FT_LOAD_NO_RECURSE )
357       load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING;
358 
359     glyph->x_scale = cidsize->metrics.x_scale;
360     glyph->y_scale = cidsize->metrics.y_scale;
361 
362     cidglyph->outline.n_points   = 0;
363     cidglyph->outline.n_contours = 0;
364 
365     hinting = FT_BOOL( ( load_flags & FT_LOAD_NO_SCALE   ) == 0 &&
366                        ( load_flags & FT_LOAD_NO_HINTING ) == 0 );
367     scaled  = FT_BOOL( ( load_flags & FT_LOAD_NO_SCALE   ) == 0 );
368 
369     glyph->hint      = hinting;
370     glyph->scaled    = scaled;
371     cidglyph->format = FT_GLYPH_FORMAT_OUTLINE;
372 
373     error = psaux->t1_decoder_funcs->init( &decoder,
374                                            cidglyph->face,
375                                            cidsize,
376                                            cidglyph,
377                                            0, /* glyph names -- XXX */
378                                            0, /* blend == 0 */
379                                            hinting,
380                                            FT_LOAD_TARGET_MODE( load_flags ),
381                                            cid_load_glyph );
382     if ( error )
383       goto Exit;
384 
385     /* TODO: initialize decoder.len_buildchar and decoder.buildchar */
386     /*       if we ever support CID-keyed multiple master fonts     */
387 
388     must_finish_decoder = TRUE;
389 
390     /* set up the decoder */
391     decoder.builder.no_recurse = FT_BOOL( load_flags & FT_LOAD_NO_RECURSE );
392 
393     error = cid_load_glyph( &decoder, glyph_index );
394     if ( error )
395       goto Exit;
396 
397     /* copy flags back for forced scaling */
398     hinting = glyph->hint;
399     scaled  = glyph->scaled;
400 
401     font_matrix = decoder.font_matrix;
402     font_offset = decoder.font_offset;
403 
404     /* save new glyph tables */
405     psaux->t1_decoder_funcs->done( &decoder );
406 
407     must_finish_decoder = FALSE;
408 
409     /* now set the metrics -- this is rather simple, as    */
410     /* the left side bearing is the xMin, and the top side */
411     /* bearing the yMax                                    */
412     cidglyph->outline.flags &= FT_OUTLINE_OWNER;
413     cidglyph->outline.flags |= FT_OUTLINE_REVERSE_FILL;
414 
415     /* for composite glyphs, return only left side bearing and */
416     /* advance width                                           */
417     if ( load_flags & FT_LOAD_NO_RECURSE )
418     {
419       FT_Slot_Internal  internal = cidglyph->internal;
420 
421 
422       cidglyph->metrics.horiBearingX =
423         FIXED_TO_INT( decoder.builder.left_bearing.x );
424       cidglyph->metrics.horiAdvance =
425         FIXED_TO_INT( decoder.builder.advance.x );
426 
427       internal->glyph_matrix      = font_matrix;
428       internal->glyph_delta       = font_offset;
429       internal->glyph_transformed = 1;
430     }
431     else
432     {
433       FT_BBox            cbox;
434       FT_Glyph_Metrics*  metrics = &cidglyph->metrics;
435 
436 
437       /* copy the _unscaled_ advance width */
438       metrics->horiAdvance =
439         FIXED_TO_INT( decoder.builder.advance.x );
440       cidglyph->linearHoriAdvance =
441         FIXED_TO_INT( decoder.builder.advance.x );
442       cidglyph->internal->glyph_transformed = 0;
443 
444       /* make up vertical ones */
445       metrics->vertAdvance        = ( face->cid.font_bbox.yMax -
446                                       face->cid.font_bbox.yMin ) >> 16;
447       cidglyph->linearVertAdvance = metrics->vertAdvance;
448 
449       cidglyph->format            = FT_GLYPH_FORMAT_OUTLINE;
450 
451       if ( cidsize->metrics.y_ppem < 24 )
452         cidglyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;
453 
454       /* apply the font matrix, if any */
455       if ( font_matrix.xx != 0x10000L || font_matrix.yy != 0x10000L ||
456            font_matrix.xy != 0        || font_matrix.yx != 0        )
457       {
458         FT_Outline_Transform( &cidglyph->outline, &font_matrix );
459 
460         metrics->horiAdvance = FT_MulFix( metrics->horiAdvance,
461                                           font_matrix.xx );
462         metrics->vertAdvance = FT_MulFix( metrics->vertAdvance,
463                                           font_matrix.yy );
464       }
465 
466       if ( font_offset.x || font_offset.y )
467       {
468         FT_Outline_Translate( &cidglyph->outline,
469                               font_offset.x,
470                               font_offset.y );
471 
472         metrics->horiAdvance += font_offset.x;
473         metrics->vertAdvance += font_offset.y;
474       }
475 
476       if ( ( load_flags & FT_LOAD_NO_SCALE ) == 0 || scaled )
477       {
478         /* scale the outline and the metrics */
479         FT_Int       n;
480         FT_Outline*  cur = decoder.builder.base;
481         FT_Vector*   vec = cur->points;
482         FT_Fixed     x_scale = glyph->x_scale;
483         FT_Fixed     y_scale = glyph->y_scale;
484 
485 
486         /* First of all, scale the points */
487         if ( !hinting || !decoder.builder.hints_funcs )
488           for ( n = cur->n_points; n > 0; n--, vec++ )
489           {
490             vec->x = FT_MulFix( vec->x, x_scale );
491             vec->y = FT_MulFix( vec->y, y_scale );
492           }
493 
494         /* Then scale the metrics */
495         metrics->horiAdvance = FT_MulFix( metrics->horiAdvance, x_scale );
496         metrics->vertAdvance = FT_MulFix( metrics->vertAdvance, y_scale );
497       }
498 
499       /* compute the other metrics */
500       FT_Outline_Get_CBox( &cidglyph->outline, &cbox );
501 
502       metrics->width  = cbox.xMax - cbox.xMin;
503       metrics->height = cbox.yMax - cbox.yMin;
504 
505       metrics->horiBearingX = cbox.xMin;
506       metrics->horiBearingY = cbox.yMax;
507 
508       if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
509       {
510         /* make up vertical ones */
511         ft_synthesize_vertical_metrics( metrics,
512                                         metrics->vertAdvance );
513       }
514     }
515 
516   Exit:
517 
518     if ( must_finish_decoder )
519       psaux->t1_decoder_funcs->done( &decoder );
520 
521     return error;
522   }
523 
524 
525 /* END */
526