1 /****************************************************************************
2  *
3  * cidgload.c
4  *
5  *   CID-keyed Type1 Glyph Loader (body).
6  *
7  * Copyright (C) 1996-2020 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 %d\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 )
80         goto Exit;
81 
82       p         = (FT_Byte*)glyph_data.pointer;
83       fd_select = cid_get_offset( &p, (FT_Byte)cid->fd_bytes );
84 
85       if ( glyph_data.length != 0 )
86       {
87         glyph_length = (FT_ULong)( glyph_data.length - cid->fd_bytes );
88         (void)FT_ALLOC( charstring, glyph_length );
89         if ( !error )
90           ft_memcpy( charstring, glyph_data.pointer + cid->fd_bytes,
91                      glyph_length );
92       }
93 
94       inc->funcs->free_glyph_data( inc->object, &glyph_data );
95 
96       if ( error )
97         goto Exit;
98     }
99 
100     else
101 
102 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
103 
104     /* For ordinary fonts read the CID font dictionary index */
105     /* and charstring offset from the CIDMap.                */
106     {
107       FT_UInt   entry_len = (FT_UInt)( cid->fd_bytes + cid->gd_bytes );
108       FT_ULong  off1, off2;
109 
110 
111       if ( FT_STREAM_SEEK( cid->data_offset + cid->cidmap_offset +
112                            glyph_index * entry_len )               ||
113            FT_FRAME_ENTER( 2 * entry_len )                         )
114         goto Exit;
115 
116       p         = (FT_Byte*)stream->cursor;
117       fd_select = cid_get_offset( &p, (FT_Byte)cid->fd_bytes );
118       off1      = cid_get_offset( &p, (FT_Byte)cid->gd_bytes );
119       p        += cid->fd_bytes;
120       off2      = cid_get_offset( &p, (FT_Byte)cid->gd_bytes );
121       FT_FRAME_EXIT();
122 
123       if ( fd_select >= (FT_ULong)cid->num_dicts ||
124            off2 > stream->size                   ||
125            off1 > off2                           )
126       {
127         FT_TRACE0(( "cid_load_glyph: invalid glyph stream offsets\n" ));
128         error = FT_THROW( Invalid_Offset );
129         goto Exit;
130       }
131 
132       glyph_length = off2 - off1;
133       if ( glyph_length == 0 )
134         goto Exit;
135       if ( FT_ALLOC( charstring, glyph_length ) )
136         goto Exit;
137       if ( FT_STREAM_READ_AT( cid->data_offset + off1,
138                               charstring, glyph_length ) )
139         goto Exit;
140     }
141 
142     /* Now set up the subrs array and parse the charstrings. */
143     {
144       CID_FaceDict  dict;
145       CID_Subrs     cid_subrs = face->subrs + fd_select;
146       FT_UInt       cs_offset;
147 
148 
149       /* Set up subrs */
150       decoder->num_subrs  = cid_subrs->num_subrs;
151       decoder->subrs      = cid_subrs->code;
152       decoder->subrs_len  = 0;
153       decoder->subrs_hash = NULL;
154 
155       /* Set up font matrix */
156       dict                 = cid->font_dicts + fd_select;
157 
158       decoder->font_matrix = dict->font_matrix;
159       decoder->font_offset = dict->font_offset;
160       decoder->lenIV       = dict->private_dict.lenIV;
161 
162       /* Decode the charstring. */
163 
164       /* Adjustment for seed bytes. */
165       cs_offset = decoder->lenIV >= 0 ? (FT_UInt)decoder->lenIV : 0;
166       if ( cs_offset > glyph_length )
167       {
168         FT_TRACE0(( "cid_load_glyph: invalid glyph stream offsets\n" ));
169         error = FT_THROW( Invalid_Offset );
170         goto Exit;
171       }
172 
173       /* Decrypt only if lenIV >= 0. */
174       if ( decoder->lenIV >= 0 )
175         psaux->t1_decrypt( charstring, glyph_length, 4330 );
176 
177       /* choose which renderer to use */
178 #ifdef T1_CONFIG_OPTION_OLD_ENGINE
179       if ( ( (PS_Driver)FT_FACE_DRIVER( face ) )->hinting_engine ==
180                FT_HINTING_FREETYPE                                  ||
181            decoder->builder.metrics_only                            )
182         error = psaux->t1_decoder_funcs->parse_charstrings_old(
183                   decoder,
184                   charstring + cs_offset,
185                   glyph_length - cs_offset );
186 #else
187       if ( decoder->builder.metrics_only )
188         error = psaux->t1_decoder_funcs->parse_metrics(
189                   decoder,
190                   charstring + cs_offset,
191                   glyph_length - cs_offset );
192 #endif
193       else
194       {
195         PS_Decoder      psdecoder;
196         CFF_SubFontRec  subfont;
197 
198 
199         psaux->ps_decoder_init( &psdecoder, decoder, TRUE );
200 
201         psaux->t1_make_subfont( FT_FACE( face ),
202                                 &dict->private_dict,
203                                 &subfont );
204         psdecoder.current_subfont = &subfont;
205 
206         error = psaux->t1_decoder_funcs->parse_charstrings(
207                   &psdecoder,
208                   charstring + cs_offset,
209                   glyph_length - cs_offset );
210 
211         /* Adobe's engine uses 16.16 numbers everywhere;              */
212         /* as a consequence, glyphs larger than 2000ppem get rejected */
213         if ( FT_ERR_EQ( error, Glyph_Too_Big ) )
214         {
215           /* this time, we retry unhinted and scale up the glyph later on */
216           /* (the engine uses and sets the hardcoded value 0x10000 / 64 = */
217           /* 0x400 for both `x_scale' and `y_scale' in this case)         */
218           ((CID_GlyphSlot)decoder->builder.glyph)->hint = FALSE;
219 
220           force_scaling = TRUE;
221 
222           error = psaux->t1_decoder_funcs->parse_charstrings(
223                     &psdecoder,
224                     charstring + cs_offset,
225                     glyph_length - cs_offset );
226         }
227       }
228     }
229 
230 #ifdef FT_CONFIG_OPTION_INCREMENTAL
231 
232     /* Incremental fonts can optionally override the metrics. */
233     if ( !error && inc && inc->funcs->get_glyph_metrics )
234     {
235       FT_Incremental_MetricsRec  metrics;
236 
237 
238       metrics.bearing_x = FIXED_TO_INT( decoder->builder.left_bearing.x );
239       metrics.bearing_y = 0;
240       metrics.advance   = FIXED_TO_INT( decoder->builder.advance.x );
241       metrics.advance_v = FIXED_TO_INT( decoder->builder.advance.y );
242 
243       error = inc->funcs->get_glyph_metrics( inc->object,
244                                              glyph_index, FALSE, &metrics );
245 
246       decoder->builder.left_bearing.x = INT_TO_FIXED( metrics.bearing_x );
247       decoder->builder.advance.x      = INT_TO_FIXED( metrics.advance );
248       decoder->builder.advance.y      = INT_TO_FIXED( metrics.advance_v );
249     }
250 
251 #endif /* FT_CONFIG_OPTION_INCREMENTAL */
252 
253   Exit:
254     FT_FREE( charstring );
255 
256     ((CID_GlyphSlot)decoder->builder.glyph)->scaled = force_scaling;
257 
258     return error;
259   }
260 
261 
262 #if 0
263 
264 
265   /*************************************************************************/
266   /*************************************************************************/
267   /*************************************************************************/
268   /**********                                                      *********/
269   /**********                                                      *********/
270   /**********            COMPUTE THE MAXIMUM ADVANCE WIDTH         *********/
271   /**********                                                      *********/
272   /**********    The following code is in charge of computing      *********/
273   /**********    the maximum advance width of the font.  It        *********/
274   /**********    quickly processes each glyph charstring to        *********/
275   /**********    extract the value from either a `sbw' or `seac'   *********/
276   /**********    operator.                                         *********/
277   /**********                                                      *********/
278   /*************************************************************************/
279   /*************************************************************************/
280   /*************************************************************************/
281 
282 
283   FT_LOCAL_DEF( FT_Error )
284   cid_face_compute_max_advance( CID_Face  face,
285                                 FT_Int*   max_advance )
286   {
287     FT_Error       error;
288     T1_DecoderRec  decoder;
289     FT_Int         glyph_index;
290 
291     PSAux_Service  psaux = (PSAux_Service)face->psaux;
292 
293 
294     *max_advance = 0;
295 
296     /* Initialize load decoder */
297     error = psaux->t1_decoder_funcs->init( &decoder,
298                                            (FT_Face)face,
299                                            0, /* size       */
300                                            0, /* glyph slot */
301                                            0, /* glyph names! XXX */
302                                            0, /* blend == 0 */
303                                            0, /* hinting == 0 */
304                                            cid_load_glyph );
305     if ( error )
306       return error;
307 
308     /* TODO: initialize decoder.len_buildchar and decoder.buildchar */
309     /*       if we ever support CID-keyed multiple master fonts     */
310 
311     decoder.builder.metrics_only = 1;
312     decoder.builder.load_points  = 0;
313 
314     /* for each glyph, parse the glyph charstring and extract */
315     /* the advance width                                      */
316     for ( glyph_index = 0; glyph_index < face->root.num_glyphs;
317           glyph_index++ )
318     {
319       /* now get load the unscaled outline */
320       error = cid_load_glyph( &decoder, glyph_index );
321       /* ignore the error if one occurred - skip to next glyph */
322     }
323 
324     *max_advance = FIXED_TO_INT( decoder.builder.advance.x );
325 
326     psaux->t1_decoder_funcs->done( &decoder );
327 
328     return FT_Err_Ok;
329   }
330 
331 
332 #endif /* 0 */
333 
334 
335   FT_LOCAL_DEF( FT_Error )
cid_slot_load_glyph(FT_GlyphSlot cidglyph,FT_Size cidsize,FT_UInt glyph_index,FT_Int32 load_flags)336   cid_slot_load_glyph( FT_GlyphSlot  cidglyph,      /* CID_GlyphSlot */
337                        FT_Size       cidsize,       /* CID_Size      */
338                        FT_UInt       glyph_index,
339                        FT_Int32      load_flags )
340   {
341     CID_GlyphSlot  glyph = (CID_GlyphSlot)cidglyph;
342     FT_Error       error;
343     T1_DecoderRec  decoder;
344     CID_Face       face = (CID_Face)cidglyph->face;
345     FT_Bool        hinting;
346     FT_Bool        scaled;
347 
348     PSAux_Service  psaux = (PSAux_Service)face->psaux;
349     FT_Matrix      font_matrix;
350     FT_Vector      font_offset;
351     FT_Bool        must_finish_decoder = FALSE;
352 
353 
354     if ( glyph_index >= (FT_UInt)face->root.num_glyphs )
355     {
356       error = FT_THROW( Invalid_Argument );
357       goto Exit;
358     }
359 
360     if ( load_flags & FT_LOAD_NO_RECURSE )
361       load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING;
362 
363     glyph->x_scale = cidsize->metrics.x_scale;
364     glyph->y_scale = cidsize->metrics.y_scale;
365 
366     cidglyph->outline.n_points   = 0;
367     cidglyph->outline.n_contours = 0;
368 
369     hinting = FT_BOOL( ( load_flags & FT_LOAD_NO_SCALE   ) == 0 &&
370                        ( load_flags & FT_LOAD_NO_HINTING ) == 0 );
371     scaled  = FT_BOOL( ( load_flags & FT_LOAD_NO_SCALE   ) == 0 );
372 
373     glyph->hint      = hinting;
374     glyph->scaled    = scaled;
375     cidglyph->format = FT_GLYPH_FORMAT_OUTLINE;
376 
377     error = psaux->t1_decoder_funcs->init( &decoder,
378                                            cidglyph->face,
379                                            cidsize,
380                                            cidglyph,
381                                            0, /* glyph names -- XXX */
382                                            0, /* blend == 0 */
383                                            hinting,
384                                            FT_LOAD_TARGET_MODE( load_flags ),
385                                            cid_load_glyph );
386     if ( error )
387       goto Exit;
388 
389     /* TODO: initialize decoder.len_buildchar and decoder.buildchar */
390     /*       if we ever support CID-keyed multiple master fonts     */
391 
392     must_finish_decoder = TRUE;
393 
394     /* set up the decoder */
395     decoder.builder.no_recurse = FT_BOOL( load_flags & FT_LOAD_NO_RECURSE );
396 
397     error = cid_load_glyph( &decoder, glyph_index );
398     if ( error )
399       goto Exit;
400 
401     /* copy flags back for forced scaling */
402     hinting = glyph->hint;
403     scaled  = glyph->scaled;
404 
405     font_matrix = decoder.font_matrix;
406     font_offset = decoder.font_offset;
407 
408     /* save new glyph tables */
409     psaux->t1_decoder_funcs->done( &decoder );
410 
411     must_finish_decoder = FALSE;
412 
413     /* now set the metrics -- this is rather simple, as    */
414     /* the left side bearing is the xMin, and the top side */
415     /* bearing the yMax                                    */
416     cidglyph->outline.flags &= FT_OUTLINE_OWNER;
417     cidglyph->outline.flags |= FT_OUTLINE_REVERSE_FILL;
418 
419     /* for composite glyphs, return only left side bearing and */
420     /* advance width                                           */
421     if ( load_flags & FT_LOAD_NO_RECURSE )
422     {
423       FT_Slot_Internal  internal = cidglyph->internal;
424 
425 
426       cidglyph->metrics.horiBearingX =
427         FIXED_TO_INT( decoder.builder.left_bearing.x );
428       cidglyph->metrics.horiAdvance =
429         FIXED_TO_INT( decoder.builder.advance.x );
430 
431       internal->glyph_matrix      = font_matrix;
432       internal->glyph_delta       = font_offset;
433       internal->glyph_transformed = 1;
434     }
435     else
436     {
437       FT_BBox            cbox;
438       FT_Glyph_Metrics*  metrics = &cidglyph->metrics;
439 
440 
441       /* copy the _unscaled_ advance width */
442       metrics->horiAdvance =
443         FIXED_TO_INT( decoder.builder.advance.x );
444       cidglyph->linearHoriAdvance =
445         FIXED_TO_INT( decoder.builder.advance.x );
446       cidglyph->internal->glyph_transformed = 0;
447 
448       /* make up vertical ones */
449       metrics->vertAdvance        = ( face->cid.font_bbox.yMax -
450                                       face->cid.font_bbox.yMin ) >> 16;
451       cidglyph->linearVertAdvance = metrics->vertAdvance;
452 
453       cidglyph->format            = FT_GLYPH_FORMAT_OUTLINE;
454 
455       if ( cidsize->metrics.y_ppem < 24 )
456         cidglyph->outline.flags |= FT_OUTLINE_HIGH_PRECISION;
457 
458       /* apply the font matrix, if any */
459       if ( font_matrix.xx != 0x10000L || font_matrix.yy != 0x10000L ||
460            font_matrix.xy != 0        || font_matrix.yx != 0        )
461       {
462         FT_Outline_Transform( &cidglyph->outline, &font_matrix );
463 
464         metrics->horiAdvance = FT_MulFix( metrics->horiAdvance,
465                                           font_matrix.xx );
466         metrics->vertAdvance = FT_MulFix( metrics->vertAdvance,
467                                           font_matrix.yy );
468       }
469 
470       if ( font_offset.x || font_offset.y )
471       {
472         FT_Outline_Translate( &cidglyph->outline,
473                               font_offset.x,
474                               font_offset.y );
475 
476         metrics->horiAdvance += font_offset.x;
477         metrics->vertAdvance += font_offset.y;
478       }
479 
480       if ( ( load_flags & FT_LOAD_NO_SCALE ) == 0 || scaled )
481       {
482         /* scale the outline and the metrics */
483         FT_Int       n;
484         FT_Outline*  cur = decoder.builder.base;
485         FT_Vector*   vec = cur->points;
486         FT_Fixed     x_scale = glyph->x_scale;
487         FT_Fixed     y_scale = glyph->y_scale;
488 
489 
490         /* First of all, scale the points */
491         if ( !hinting || !decoder.builder.hints_funcs )
492           for ( n = cur->n_points; n > 0; n--, vec++ )
493           {
494             vec->x = FT_MulFix( vec->x, x_scale );
495             vec->y = FT_MulFix( vec->y, y_scale );
496           }
497 
498         /* Then scale the metrics */
499         metrics->horiAdvance = FT_MulFix( metrics->horiAdvance, x_scale );
500         metrics->vertAdvance = FT_MulFix( metrics->vertAdvance, y_scale );
501       }
502 
503       /* compute the other metrics */
504       FT_Outline_Get_CBox( &cidglyph->outline, &cbox );
505 
506       metrics->width  = cbox.xMax - cbox.xMin;
507       metrics->height = cbox.yMax - cbox.yMin;
508 
509       metrics->horiBearingX = cbox.xMin;
510       metrics->horiBearingY = cbox.yMax;
511 
512       if ( load_flags & FT_LOAD_VERTICAL_LAYOUT )
513       {
514         /* make up vertical ones */
515         ft_synthesize_vertical_metrics( metrics,
516                                         metrics->vertAdvance );
517       }
518     }
519 
520   Exit:
521 
522     if ( must_finish_decoder )
523       psaux->t1_decoder_funcs->done( &decoder );
524 
525     return error;
526   }
527 
528 
529 /* END */
530