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1 /****************************************************************************
2  *
3  * afcjk.c
4  *
5  *   Auto-fitter hinting routines for CJK writing system (body).
6  *
7  * Copyright (C) 2006-2023 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    * The algorithm is based on akito's autohint patch, archived at
20    *
21    * https://web.archive.org/web/20051219160454/http://www.kde.gr.jp:80/~akito/patch/freetype2/2.1.7/
22    *
23    */
24 
25 #include <freetype/ftadvanc.h>
26 #include <freetype/internal/ftdebug.h>
27 
28 #include "afglobal.h"
29 #include "aflatin.h"
30 #include "afcjk.h"
31 
32 
33 #ifdef AF_CONFIG_OPTION_CJK
34 
35 #undef AF_CONFIG_OPTION_CJK_BLUE_HANI_VERT
36 
37 #include "aferrors.h"
38 
39 
40   /**************************************************************************
41    *
42    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
43    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
44    * messages during execution.
45    */
46 #undef  FT_COMPONENT
47 #define FT_COMPONENT  afcjk
48 
49 
50   /*************************************************************************/
51   /*************************************************************************/
52   /*****                                                               *****/
53   /*****              C J K   G L O B A L   M E T R I C S              *****/
54   /*****                                                               *****/
55   /*************************************************************************/
56   /*************************************************************************/
57 
58 
59   /* Basically the Latin version with AF_CJKMetrics */
60   /* to replace AF_LatinMetrics.                    */
61 
62   FT_LOCAL_DEF( void )
af_cjk_metrics_init_widths(AF_CJKMetrics metrics,FT_Face face)63   af_cjk_metrics_init_widths( AF_CJKMetrics  metrics,
64                               FT_Face        face )
65   {
66     /* scan the array of segments in each direction */
67     AF_GlyphHintsRec  hints[1];
68 
69 
70     FT_TRACE5(( "\n" ));
71     FT_TRACE5(( "cjk standard widths computation (style `%s')\n",
72                 af_style_names[metrics->root.style_class->style] ));
73     FT_TRACE5(( "===================================================\n" ));
74     FT_TRACE5(( "\n" ));
75 
76     af_glyph_hints_init( hints, face->memory );
77 
78     metrics->axis[AF_DIMENSION_HORZ].width_count = 0;
79     metrics->axis[AF_DIMENSION_VERT].width_count = 0;
80 
81     {
82       FT_Error          error;
83       FT_ULong          glyph_index;
84       int               dim;
85       AF_CJKMetricsRec  dummy[1];
86       AF_Scaler         scaler = &dummy->root.scaler;
87 
88       AF_StyleClass   style_class  = metrics->root.style_class;
89       AF_ScriptClass  script_class = af_script_classes[style_class->script];
90 
91       /* If HarfBuzz is not available, we need a pointer to a single */
92       /* unsigned long value.                                        */
93 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
94       void*     shaper_buf;
95 #else
96       FT_ULong  shaper_buf_;
97       void*     shaper_buf = &shaper_buf_;
98 #endif
99 
100       const char*  p;
101 
102 #ifdef FT_DEBUG_LEVEL_TRACE
103       FT_ULong  ch = 0;
104 #endif
105 
106       p = script_class->standard_charstring;
107 
108 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
109       shaper_buf = af_shaper_buf_create( face );
110 #endif
111 
112       /* We check a list of standard characters.  The first match wins. */
113 
114       glyph_index = 0;
115       while ( *p )
116       {
117         unsigned int  num_idx;
118 
119 #ifdef FT_DEBUG_LEVEL_TRACE
120         const char*  p_old;
121 #endif
122 
123 
124         while ( *p == ' ' )
125           p++;
126 
127 #ifdef FT_DEBUG_LEVEL_TRACE
128         p_old = p;
129         GET_UTF8_CHAR( ch, p_old );
130 #endif
131 
132         /* reject input that maps to more than a single glyph */
133         p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
134         if ( num_idx > 1 )
135           continue;
136 
137         /* otherwise exit loop if we have a result */
138         glyph_index = af_shaper_get_elem( &metrics->root,
139                                           shaper_buf,
140                                           0,
141                                           NULL,
142                                           NULL );
143         if ( glyph_index )
144           break;
145       }
146 
147       af_shaper_buf_destroy( face, shaper_buf );
148 
149       if ( !glyph_index )
150         goto Exit;
151 
152       if ( !glyph_index )
153         goto Exit;
154 
155       FT_TRACE5(( "standard character: U+%04lX (glyph index %ld)\n",
156                   ch, glyph_index ));
157 
158       error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
159       if ( error || face->glyph->outline.n_points <= 0 )
160         goto Exit;
161 
162       FT_ZERO( dummy );
163 
164       dummy->units_per_em = metrics->units_per_em;
165 
166       scaler->x_scale = 0x10000L;
167       scaler->y_scale = 0x10000L;
168       scaler->x_delta = 0;
169       scaler->y_delta = 0;
170 
171       scaler->face        = face;
172       scaler->render_mode = FT_RENDER_MODE_NORMAL;
173       scaler->flags       = 0;
174 
175       af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy );
176 
177       error = af_glyph_hints_reload( hints, &face->glyph->outline );
178       if ( error )
179         goto Exit;
180 
181       for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
182       {
183         AF_CJKAxis    axis    = &metrics->axis[dim];
184         AF_AxisHints  axhints = &hints->axis[dim];
185         AF_Segment    seg, limit, link;
186         FT_UInt       num_widths = 0;
187 
188 
189         error = af_latin_hints_compute_segments( hints,
190                                                  (AF_Dimension)dim );
191         if ( error )
192           goto Exit;
193 
194         /*
195          * We assume that the glyphs selected for the stem width
196          * computation are `featureless' enough so that the linking
197          * algorithm works fine without adjustments of its scoring
198          * function.
199          */
200         af_latin_hints_link_segments( hints,
201                                       0,
202                                       NULL,
203                                       (AF_Dimension)dim );
204 
205         seg   = axhints->segments;
206         limit = seg + axhints->num_segments;
207 
208         for ( ; seg < limit; seg++ )
209         {
210           link = seg->link;
211 
212           /* we only consider stem segments there! */
213           if ( link && link->link == seg && link > seg )
214           {
215             FT_Pos  dist;
216 
217 
218             dist = seg->pos - link->pos;
219             if ( dist < 0 )
220               dist = -dist;
221 
222             if ( num_widths < AF_CJK_MAX_WIDTHS )
223               axis->widths[num_widths++].org = dist;
224           }
225         }
226 
227         /* this also replaces multiple almost identical stem widths */
228         /* with a single one (the value 100 is heuristic)           */
229         af_sort_and_quantize_widths( &num_widths, axis->widths,
230                                      dummy->units_per_em / 100 );
231         axis->width_count = num_widths;
232       }
233 
234     Exit:
235       for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
236       {
237         AF_CJKAxis  axis = &metrics->axis[dim];
238         FT_Pos      stdw;
239 
240 
241         stdw = ( axis->width_count > 0 ) ? axis->widths[0].org
242                                          : AF_LATIN_CONSTANT( metrics, 50 );
243 
244         /* let's try 20% of the smallest width */
245         axis->edge_distance_threshold = stdw / 5;
246         axis->standard_width          = stdw;
247         axis->extra_light             = 0;
248 
249 #ifdef FT_DEBUG_LEVEL_TRACE
250         {
251           FT_UInt  i;
252 
253 
254           FT_TRACE5(( "%s widths:\n",
255                       dim == AF_DIMENSION_VERT ? "horizontal"
256                                                : "vertical" ));
257 
258           FT_TRACE5(( "  %ld (standard)", axis->standard_width ));
259           for ( i = 1; i < axis->width_count; i++ )
260             FT_TRACE5(( " %ld", axis->widths[i].org ));
261 
262           FT_TRACE5(( "\n" ));
263         }
264 #endif
265       }
266     }
267 
268     FT_TRACE5(( "\n" ));
269 
270     af_glyph_hints_done( hints );
271   }
272 
273 
274   /* Find all blue zones. */
275 
276   static void
af_cjk_metrics_init_blues(AF_CJKMetrics metrics,FT_Face face)277   af_cjk_metrics_init_blues( AF_CJKMetrics  metrics,
278                              FT_Face        face )
279   {
280     FT_Pos      fills[AF_BLUE_STRING_MAX_LEN];
281     FT_Pos      flats[AF_BLUE_STRING_MAX_LEN];
282 
283     FT_UInt     num_fills;
284     FT_UInt     num_flats;
285 
286     FT_Bool     fill;
287 
288     AF_CJKBlue  blue;
289     FT_Error    error;
290     AF_CJKAxis  axis;
291     FT_Outline  outline;
292 
293     AF_StyleClass  sc = metrics->root.style_class;
294 
295     AF_Blue_Stringset         bss = sc->blue_stringset;
296     const AF_Blue_StringRec*  bs  = &af_blue_stringsets[bss];
297 
298     /* If HarfBuzz is not available, we need a pointer to a single */
299     /* unsigned long value.                                        */
300 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
301     void*     shaper_buf;
302 #else
303     FT_ULong  shaper_buf_;
304     void*     shaper_buf = &shaper_buf_;
305 #endif
306 
307 
308     /* we walk over the blue character strings as specified in the   */
309     /* style's entry in the `af_blue_stringset' array, computing its */
310     /* extremum points (depending on the string properties)          */
311 
312     FT_TRACE5(( "cjk blue zones computation\n" ));
313     FT_TRACE5(( "==========================\n" ));
314     FT_TRACE5(( "\n" ));
315 
316 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
317     shaper_buf = af_shaper_buf_create( face );
318 #endif
319 
320     for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ )
321     {
322       const char*  p = &af_blue_strings[bs->string];
323       FT_Pos*      blue_ref;
324       FT_Pos*      blue_shoot;
325 
326 
327       if ( AF_CJK_IS_HORIZ_BLUE( bs ) )
328         axis = &metrics->axis[AF_DIMENSION_HORZ];
329       else
330         axis = &metrics->axis[AF_DIMENSION_VERT];
331 
332 #ifdef FT_DEBUG_LEVEL_TRACE
333       {
334         FT_String*  cjk_blue_name[4] =
335         {
336           (FT_String*)"bottom",    /* --   , --  */
337           (FT_String*)"top",       /* --   , TOP */
338           (FT_String*)"left",      /* HORIZ, --  */
339           (FT_String*)"right"      /* HORIZ, TOP */
340         };
341 
342 
343         FT_TRACE5(( "blue zone %d (%s):\n",
344                     axis->blue_count,
345                     cjk_blue_name[AF_CJK_IS_HORIZ_BLUE( bs ) |
346                                   AF_CJK_IS_TOP_BLUE( bs )   ] ));
347       }
348 #endif /* FT_DEBUG_LEVEL_TRACE */
349 
350       num_fills = 0;
351       num_flats = 0;
352 
353       fill = 1;  /* start with characters that define fill values */
354       FT_TRACE5(( "  [overshoot values]\n" ));
355 
356       while ( *p )
357       {
358         FT_ULong    glyph_index;
359         FT_Pos      best_pos;       /* same as points.y or points.x, resp. */
360         FT_Int      best_point;
361         FT_Vector*  points;
362 
363         unsigned int  num_idx;
364 
365 #ifdef FT_DEBUG_LEVEL_TRACE
366         const char*  p_old;
367         FT_ULong     ch;
368 #endif
369 
370 
371         while ( *p == ' ' )
372           p++;
373 
374 #ifdef FT_DEBUG_LEVEL_TRACE
375         p_old = p;
376         GET_UTF8_CHAR( ch, p_old );
377 #endif
378 
379         /* switch to characters that define flat values */
380         if ( *p == '|' )
381         {
382           fill = 0;
383           FT_TRACE5(( "  [reference values]\n" ));
384           p++;
385           continue;
386         }
387 
388         /* reject input that maps to more than a single glyph */
389         p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
390         if ( num_idx > 1 )
391           continue;
392 
393         /* load the character in the face -- skip unknown or empty ones */
394         glyph_index = af_shaper_get_elem( &metrics->root,
395                                           shaper_buf,
396                                           0,
397                                           NULL,
398                                           NULL );
399         if ( glyph_index == 0 )
400         {
401           FT_TRACE5(( "  U+%04lX unavailable\n", ch ));
402           continue;
403         }
404 
405         error   = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
406         outline = face->glyph->outline;
407         if ( error || outline.n_points <= 2 )
408         {
409           FT_TRACE5(( "  U+%04lX contains no (usable) outlines\n", ch ));
410           continue;
411         }
412 
413         /* now compute min or max point indices and coordinates */
414         points     = outline.points;
415         best_point = -1;
416         best_pos   = 0;  /* make compiler happy */
417 
418         {
419           FT_Int  nn;
420           FT_Int  first = 0;
421           FT_Int  last  = -1;
422 
423 
424           for ( nn = 0; nn < outline.n_contours; first = last + 1, nn++ )
425           {
426             FT_Int  pp;
427 
428 
429             last = outline.contours[nn];
430 
431             /* Avoid single-point contours since they are never rasterized. */
432             /* In some fonts, they correspond to mark attachment points     */
433             /* which are way outside of the glyph's real outline.           */
434             if ( last <= first )
435               continue;
436 
437             if ( AF_CJK_IS_HORIZ_BLUE( bs ) )
438             {
439               if ( AF_CJK_IS_RIGHT_BLUE( bs ) )
440               {
441                 for ( pp = first; pp <= last; pp++ )
442                   if ( best_point < 0 || points[pp].x > best_pos )
443                   {
444                     best_point = pp;
445                     best_pos   = points[pp].x;
446                   }
447               }
448               else
449               {
450                 for ( pp = first; pp <= last; pp++ )
451                   if ( best_point < 0 || points[pp].x < best_pos )
452                   {
453                     best_point = pp;
454                     best_pos   = points[pp].x;
455                   }
456               }
457             }
458             else
459             {
460               if ( AF_CJK_IS_TOP_BLUE( bs ) )
461               {
462                 for ( pp = first; pp <= last; pp++ )
463                   if ( best_point < 0 || points[pp].y > best_pos )
464                   {
465                     best_point = pp;
466                     best_pos   = points[pp].y;
467                   }
468               }
469               else
470               {
471                 for ( pp = first; pp <= last; pp++ )
472                   if ( best_point < 0 || points[pp].y < best_pos )
473                   {
474                     best_point = pp;
475                     best_pos   = points[pp].y;
476                   }
477               }
478             }
479           }
480 
481           FT_TRACE5(( "  U+%04lX: best_pos = %5ld\n", ch, best_pos ));
482         }
483 
484         if ( fill )
485           fills[num_fills++] = best_pos;
486         else
487           flats[num_flats++] = best_pos;
488 
489       } /* end while loop */
490 
491       if ( num_flats == 0 && num_fills == 0 )
492       {
493         /*
494          * we couldn't find a single glyph to compute this blue zone,
495          * we will simply ignore it then
496          */
497         FT_TRACE5(( "  empty\n" ));
498         continue;
499       }
500 
501       /* we have computed the contents of the `fill' and `flats' tables,   */
502       /* now determine the reference and overshoot position of the blue -- */
503       /* we simply take the median value after a simple sort               */
504       af_sort_pos( num_fills, fills );
505       af_sort_pos( num_flats, flats );
506 
507       blue       = &axis->blues[axis->blue_count];
508       blue_ref   = &blue->ref.org;
509       blue_shoot = &blue->shoot.org;
510 
511       axis->blue_count++;
512 
513       if ( num_flats == 0 )
514       {
515         *blue_ref   =
516         *blue_shoot = fills[num_fills / 2];
517       }
518       else if ( num_fills == 0 )
519       {
520         *blue_ref   =
521         *blue_shoot = flats[num_flats / 2];
522       }
523       else
524       {
525         *blue_ref   = fills[num_fills / 2];
526         *blue_shoot = flats[num_flats / 2];
527       }
528 
529       /* make sure blue_ref >= blue_shoot for top/right or */
530       /* vice versa for bottom/left                        */
531       if ( *blue_shoot != *blue_ref )
532       {
533         FT_Pos   ref       = *blue_ref;
534         FT_Pos   shoot     = *blue_shoot;
535         FT_Bool  under_ref = FT_BOOL( shoot < ref );
536 
537 
538         /* AF_CJK_IS_TOP_BLUE covers `right' and `top' */
539         if ( AF_CJK_IS_TOP_BLUE( bs ) ^ under_ref )
540         {
541           *blue_ref   =
542           *blue_shoot = ( shoot + ref ) / 2;
543 
544           FT_TRACE5(( "  [reference smaller than overshoot,"
545                       " taking mean value]\n" ));
546         }
547       }
548 
549       blue->flags = 0;
550       if ( AF_CJK_IS_TOP_BLUE( bs ) )
551         blue->flags |= AF_CJK_BLUE_TOP;
552 
553       FT_TRACE5(( "    -> reference = %ld\n", *blue_ref ));
554       FT_TRACE5(( "       overshoot = %ld\n", *blue_shoot ));
555 
556     } /* end for loop */
557 
558     af_shaper_buf_destroy( face, shaper_buf );
559 
560     FT_TRACE5(( "\n" ));
561 
562     return;
563   }
564 
565 
566   /* Basically the Latin version with type AF_CJKMetrics for metrics. */
567 
568   FT_LOCAL_DEF( void )
af_cjk_metrics_check_digits(AF_CJKMetrics metrics,FT_Face face)569   af_cjk_metrics_check_digits( AF_CJKMetrics  metrics,
570                                FT_Face        face )
571   {
572     FT_Bool   started = 0, same_width = 1;
573     FT_Fixed  advance = 0, old_advance = 0;
574 
575     /* If HarfBuzz is not available, we need a pointer to a single */
576     /* unsigned long value.                                        */
577 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
578     void*     shaper_buf;
579 #else
580     FT_ULong  shaper_buf_;
581     void*     shaper_buf = &shaper_buf_;
582 #endif
583 
584     /* in all supported charmaps, digits have character codes 0x30-0x39 */
585     const char   digits[] = "0 1 2 3 4 5 6 7 8 9";
586     const char*  p;
587 
588 
589     p = digits;
590 
591 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
592     shaper_buf = af_shaper_buf_create( face );
593 #endif
594 
595     while ( *p )
596     {
597       FT_ULong      glyph_index;
598       unsigned int  num_idx;
599 
600 
601       /* reject input that maps to more than a single glyph */
602       p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
603       if ( num_idx > 1 )
604         continue;
605 
606       glyph_index = af_shaper_get_elem( &metrics->root,
607                                         shaper_buf,
608                                         0,
609                                         &advance,
610                                         NULL );
611       if ( !glyph_index )
612         continue;
613 
614       if ( started )
615       {
616         if ( advance != old_advance )
617         {
618           same_width = 0;
619           break;
620         }
621       }
622       else
623       {
624         old_advance = advance;
625         started     = 1;
626       }
627     }
628 
629     af_shaper_buf_destroy( face, shaper_buf );
630 
631     metrics->root.digits_have_same_width = same_width;
632   }
633 
634 
635   /* Initialize global metrics. */
636 
637   FT_LOCAL_DEF( FT_Error )
af_cjk_metrics_init(AF_CJKMetrics metrics,FT_Face face)638   af_cjk_metrics_init( AF_CJKMetrics  metrics,
639                        FT_Face        face )
640   {
641     FT_CharMap  oldmap = face->charmap;
642 
643 
644     metrics->units_per_em = face->units_per_EM;
645 
646     if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
647     {
648       af_cjk_metrics_init_widths( metrics, face );
649       af_cjk_metrics_init_blues( metrics, face );
650       af_cjk_metrics_check_digits( metrics, face );
651     }
652 
653     face->charmap = oldmap;
654     return FT_Err_Ok;
655   }
656 
657 
658   /* Adjust scaling value, then scale and shift widths   */
659   /* and blue zones (if applicable) for given dimension. */
660 
661   static void
af_cjk_metrics_scale_dim(AF_CJKMetrics metrics,AF_Scaler scaler,AF_Dimension dim)662   af_cjk_metrics_scale_dim( AF_CJKMetrics  metrics,
663                             AF_Scaler      scaler,
664                             AF_Dimension   dim )
665   {
666     FT_Fixed    scale;
667     FT_Pos      delta;
668     AF_CJKAxis  axis;
669     FT_UInt     nn;
670 
671 
672     if ( dim == AF_DIMENSION_HORZ )
673     {
674       scale = scaler->x_scale;
675       delta = scaler->x_delta;
676     }
677     else
678     {
679       scale = scaler->y_scale;
680       delta = scaler->y_delta;
681     }
682 
683     axis = &metrics->axis[dim];
684 
685     if ( axis->org_scale == scale && axis->org_delta == delta )
686       return;
687 
688     axis->org_scale = scale;
689     axis->org_delta = delta;
690 
691     axis->scale = scale;
692     axis->delta = delta;
693 
694     /* scale the blue zones */
695     for ( nn = 0; nn < axis->blue_count; nn++ )
696     {
697       AF_CJKBlue  blue = &axis->blues[nn];
698       FT_Pos      dist;
699 
700 
701       blue->ref.cur   = FT_MulFix( blue->ref.org, scale ) + delta;
702       blue->ref.fit   = blue->ref.cur;
703       blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
704       blue->shoot.fit = blue->shoot.cur;
705       blue->flags    &= ~AF_CJK_BLUE_ACTIVE;
706 
707       /* a blue zone is only active if it is less than 3/4 pixels tall */
708       dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
709       if ( dist <= 48 && dist >= -48 )
710       {
711         FT_Pos  delta1, delta2;
712 
713 
714         blue->ref.fit  = FT_PIX_ROUND( blue->ref.cur );
715 
716         /* shoot is under shoot for cjk */
717         delta1 = FT_DivFix( blue->ref.fit, scale ) - blue->shoot.org;
718         delta2 = delta1;
719         if ( delta1 < 0 )
720           delta2 = -delta2;
721 
722         delta2 = FT_MulFix( delta2, scale );
723 
724         FT_TRACE5(( "delta: %ld", delta1 ));
725         if ( delta2 < 32 )
726           delta2 = 0;
727 #if 0
728         else if ( delta2 < 64 )
729           delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
730 #endif
731         else
732           delta2 = FT_PIX_ROUND( delta2 );
733         FT_TRACE5(( "/%ld\n", delta2 ));
734 
735         if ( delta1 < 0 )
736           delta2 = -delta2;
737 
738         blue->shoot.fit = blue->ref.fit - delta2;
739 
740         FT_TRACE5(( ">> active cjk blue zone %c%d[%ld/%ld]:\n",
741                     ( dim == AF_DIMENSION_HORZ ) ? 'H' : 'V',
742                     nn, blue->ref.org, blue->shoot.org ));
743         FT_TRACE5(( "     ref:   cur=%.2f fit=%.2f\n",
744                     (double)blue->ref.cur / 64,
745                     (double)blue->ref.fit / 64 ));
746         FT_TRACE5(( "     shoot: cur=%.2f fit=%.2f\n",
747                     (double)blue->shoot.cur / 64,
748                     (double)blue->shoot.fit / 64 ));
749 
750         blue->flags |= AF_CJK_BLUE_ACTIVE;
751       }
752     }
753   }
754 
755 
756   /* Scale global values in both directions. */
757 
758   FT_LOCAL_DEF( void )
af_cjk_metrics_scale(AF_CJKMetrics metrics,AF_Scaler scaler)759   af_cjk_metrics_scale( AF_CJKMetrics  metrics,
760                         AF_Scaler      scaler )
761   {
762     /* we copy the whole structure since the x and y scaling values */
763     /* are not modified, contrary to e.g. the `latin' auto-hinter   */
764     metrics->root.scaler = *scaler;
765 
766     af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
767     af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
768   }
769 
770 
771   /* Extract standard_width from writing system/script specific */
772   /* metrics class.                                             */
773 
774   FT_LOCAL_DEF( void )
af_cjk_get_standard_widths(AF_CJKMetrics metrics,FT_Pos * stdHW,FT_Pos * stdVW)775   af_cjk_get_standard_widths( AF_CJKMetrics  metrics,
776                               FT_Pos*        stdHW,
777                               FT_Pos*        stdVW )
778   {
779     if ( stdHW )
780       *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width;
781 
782     if ( stdVW )
783       *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width;
784   }
785 
786 
787   /*************************************************************************/
788   /*************************************************************************/
789   /*****                                                               *****/
790   /*****              C J K   G L Y P H   A N A L Y S I S              *****/
791   /*****                                                               *****/
792   /*************************************************************************/
793   /*************************************************************************/
794 
795 
796   /* Walk over all contours and compute its segments. */
797 
798   static FT_Error
af_cjk_hints_compute_segments(AF_GlyphHints hints,AF_Dimension dim)799   af_cjk_hints_compute_segments( AF_GlyphHints  hints,
800                                  AF_Dimension   dim )
801   {
802     AF_AxisHints  axis          = &hints->axis[dim];
803     AF_Segment    segments      = axis->segments;
804     AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
805     FT_Error      error;
806     AF_Segment    seg;
807 
808 
809     error = af_latin_hints_compute_segments( hints, dim );
810     if ( error )
811       return error;
812 
813     /* a segment is round if it doesn't have successive */
814     /* on-curve points.                                 */
815     for ( seg = segments; seg < segment_limit; seg++ )
816     {
817       AF_Point  pt   = seg->first;
818       AF_Point  last = seg->last;
819       FT_UInt   f0   = pt->flags & AF_FLAG_CONTROL;
820       FT_UInt   f1;
821 
822 
823       seg->flags &= ~AF_EDGE_ROUND;
824 
825       for ( ; pt != last; f0 = f1 )
826       {
827         pt = pt->next;
828         f1 = pt->flags & AF_FLAG_CONTROL;
829 
830         if ( !f0 && !f1 )
831           break;
832 
833         if ( pt == last )
834           seg->flags |= AF_EDGE_ROUND;
835       }
836     }
837 
838     return FT_Err_Ok;
839   }
840 
841 
842   static void
af_cjk_hints_link_segments(AF_GlyphHints hints,AF_Dimension dim)843   af_cjk_hints_link_segments( AF_GlyphHints  hints,
844                               AF_Dimension   dim )
845   {
846     AF_AxisHints  axis          = &hints->axis[dim];
847     AF_Segment    segments      = axis->segments;
848     AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
849     AF_Direction  major_dir     = axis->major_dir;
850     AF_Segment    seg1, seg2;
851     FT_Pos        len_threshold;
852     FT_Pos        dist_threshold;
853 
854 
855     len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
856 
857     dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
858                                                   : hints->y_scale;
859     dist_threshold = FT_DivFix( 64 * 3, dist_threshold );
860 
861     /* now compare each segment to the others */
862     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
863     {
864       if ( seg1->dir != major_dir )
865         continue;
866 
867       for ( seg2 = segments; seg2 < segment_limit; seg2++ )
868         if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
869         {
870           FT_Pos  dist = seg2->pos - seg1->pos;
871 
872 
873           if ( dist < 0 )
874             continue;
875 
876           {
877             FT_Pos  min = seg1->min_coord;
878             FT_Pos  max = seg1->max_coord;
879             FT_Pos  len;
880 
881 
882             if ( min < seg2->min_coord )
883               min = seg2->min_coord;
884 
885             if ( max > seg2->max_coord )
886               max = seg2->max_coord;
887 
888             len = max - min;
889             if ( len >= len_threshold )
890             {
891               if ( dist * 8 < seg1->score * 9                        &&
892                    ( dist * 8 < seg1->score * 7 || seg1->len < len ) )
893               {
894                 seg1->score = dist;
895                 seg1->len   = len;
896                 seg1->link  = seg2;
897               }
898 
899               if ( dist * 8 < seg2->score * 9                        &&
900                    ( dist * 8 < seg2->score * 7 || seg2->len < len ) )
901               {
902                 seg2->score = dist;
903                 seg2->len   = len;
904                 seg2->link  = seg1;
905               }
906             }
907           }
908         }
909     }
910 
911     /*
912      * now compute the `serif' segments
913      *
914      * In Hanzi, some strokes are wider on one or both of the ends.
915      * We either identify the stems on the ends as serifs or remove
916      * the linkage, depending on the length of the stems.
917      *
918      */
919 
920     {
921       AF_Segment  link1, link2;
922 
923 
924       for ( seg1 = segments; seg1 < segment_limit; seg1++ )
925       {
926         link1 = seg1->link;
927         if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos )
928           continue;
929 
930         if ( seg1->score >= dist_threshold )
931           continue;
932 
933         for ( seg2 = segments; seg2 < segment_limit; seg2++ )
934         {
935           if ( seg2->pos > seg1->pos || seg1 == seg2 )
936             continue;
937 
938           link2 = seg2->link;
939           if ( !link2 || link2->link != seg2 || link2->pos < link1->pos )
940             continue;
941 
942           if ( seg1->pos == seg2->pos && link1->pos == link2->pos )
943             continue;
944 
945           if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score )
946             continue;
947 
948           /* seg2 < seg1 < link1 < link2 */
949 
950           if ( seg1->len >= seg2->len * 3 )
951           {
952             AF_Segment  seg;
953 
954 
955             for ( seg = segments; seg < segment_limit; seg++ )
956             {
957               AF_Segment  link = seg->link;
958 
959 
960               if ( link == seg2 )
961               {
962                 seg->link  = NULL;
963                 seg->serif = link1;
964               }
965               else if ( link == link2 )
966               {
967                 seg->link  = NULL;
968                 seg->serif = seg1;
969               }
970             }
971           }
972           else
973           {
974             seg1->link = link1->link = NULL;
975 
976             break;
977           }
978         }
979       }
980     }
981 
982     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
983     {
984       seg2 = seg1->link;
985 
986       if ( seg2 )
987       {
988         if ( seg2->link != seg1 )
989         {
990           seg1->link = NULL;
991 
992           if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 )
993             seg1->serif = seg2->link;
994         }
995       }
996     }
997   }
998 
999 
1000   static FT_Error
af_cjk_hints_compute_edges(AF_GlyphHints hints,AF_Dimension dim)1001   af_cjk_hints_compute_edges( AF_GlyphHints  hints,
1002                               AF_Dimension   dim )
1003   {
1004     AF_AxisHints  axis   = &hints->axis[dim];
1005     FT_Error      error  = FT_Err_Ok;
1006     FT_Memory     memory = hints->memory;
1007     AF_CJKAxis    laxis  = &((AF_CJKMetrics)hints->metrics)->axis[dim];
1008 
1009     AF_Segment    segments      = axis->segments;
1010     AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
1011     AF_Segment    seg;
1012 
1013     FT_Fixed      scale;
1014     FT_Pos        edge_distance_threshold;
1015 
1016 
1017     axis->num_edges = 0;
1018 
1019     scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
1020                                          : hints->y_scale;
1021 
1022     /**********************************************************************
1023      *
1024      * We begin by generating a sorted table of edges for the current
1025      * direction.  To do so, we simply scan each segment and try to find
1026      * an edge in our table that corresponds to its position.
1027      *
1028      * If no edge is found, we create and insert a new edge in the
1029      * sorted table.  Otherwise, we simply add the segment to the edge's
1030      * list which is then processed in the second step to compute the
1031      * edge's properties.
1032      *
1033      * Note that the edges table is sorted along the segment/edge
1034      * position.
1035      *
1036      */
1037 
1038     edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
1039                                          scale );
1040     if ( edge_distance_threshold > 64 / 4 )
1041       edge_distance_threshold = FT_DivFix( 64 / 4, scale );
1042     else
1043       edge_distance_threshold = laxis->edge_distance_threshold;
1044 
1045     for ( seg = segments; seg < segment_limit; seg++ )
1046     {
1047       AF_Edge  found = NULL;
1048       FT_Pos   best  = 0xFFFFU;
1049       FT_UInt  ee;
1050 
1051 
1052       /* look for an edge corresponding to the segment */
1053       for ( ee = 0; ee < axis->num_edges; ee++ )
1054       {
1055         AF_Edge  edge = axis->edges + ee;
1056         FT_Pos   dist;
1057 
1058 
1059         if ( edge->dir != seg->dir )
1060           continue;
1061 
1062         dist = seg->pos - edge->fpos;
1063         if ( dist < 0 )
1064           dist = -dist;
1065 
1066         if ( dist < edge_distance_threshold && dist < best )
1067         {
1068           AF_Segment  link = seg->link;
1069 
1070 
1071           /* check whether all linked segments of the candidate edge */
1072           /* can make a single edge.                                 */
1073           if ( link )
1074           {
1075             AF_Segment  seg1  = edge->first;
1076             FT_Pos      dist2 = 0;
1077 
1078 
1079             do
1080             {
1081               AF_Segment  link1 = seg1->link;
1082 
1083 
1084               if ( link1 )
1085               {
1086                 dist2 = AF_SEGMENT_DIST( link, link1 );
1087                 if ( dist2 >= edge_distance_threshold )
1088                   break;
1089               }
1090 
1091             } while ( ( seg1 = seg1->edge_next ) != edge->first );
1092 
1093             if ( dist2 >= edge_distance_threshold )
1094               continue;
1095           }
1096 
1097           best  = dist;
1098           found = edge;
1099         }
1100       }
1101 
1102       if ( !found )
1103       {
1104         AF_Edge  edge;
1105 
1106 
1107         /* insert a new edge in the list and */
1108         /* sort according to the position    */
1109         error = af_axis_hints_new_edge( axis, seg->pos,
1110                                         (AF_Direction)seg->dir, 0,
1111                                         memory, &edge );
1112         if ( error )
1113           goto Exit;
1114 
1115         /* add the segment to the new edge's list */
1116         FT_ZERO( edge );
1117 
1118         edge->first    = seg;
1119         edge->last     = seg;
1120         edge->dir      = seg->dir;
1121         edge->fpos     = seg->pos;
1122         edge->opos     = FT_MulFix( seg->pos, scale );
1123         edge->pos      = edge->opos;
1124         seg->edge_next = seg;
1125       }
1126       else
1127       {
1128         /* if an edge was found, simply add the segment to the edge's */
1129         /* list                                                       */
1130         seg->edge_next         = found->first;
1131         found->last->edge_next = seg;
1132         found->last            = seg;
1133       }
1134     }
1135 
1136     /*******************************************************************
1137      *
1138      * Good, we now compute each edge's properties according to the
1139      * segments found on its position.  Basically, these are
1140      *
1141      * - the edge's main direction
1142      * - stem edge, serif edge or both (which defaults to stem then)
1143      * - rounded edge, straight or both (which defaults to straight)
1144      * - link for edge
1145      *
1146      */
1147 
1148     /* first of all, set the `edge' field in each segment -- this is */
1149     /* required in order to compute edge links                       */
1150 
1151     /*
1152      * Note that removing this loop and setting the `edge' field of each
1153      * segment directly in the code above slows down execution speed for
1154      * some reasons on platforms like the Sun.
1155      */
1156     {
1157       AF_Edge  edges      = axis->edges;
1158       AF_Edge  edge_limit = FT_OFFSET( edges, axis->num_edges );
1159       AF_Edge  edge;
1160 
1161 
1162       for ( edge = edges; edge < edge_limit; edge++ )
1163       {
1164         seg = edge->first;
1165         if ( seg )
1166           do
1167           {
1168             seg->edge = edge;
1169             seg       = seg->edge_next;
1170 
1171           } while ( seg != edge->first );
1172       }
1173 
1174       /* now compute each edge properties */
1175       for ( edge = edges; edge < edge_limit; edge++ )
1176       {
1177         FT_Int  is_round    = 0;  /* does it contain round segments?    */
1178         FT_Int  is_straight = 0;  /* does it contain straight segments? */
1179 
1180 
1181         seg = edge->first;
1182         if ( !seg )
1183           goto Skip_Loop;
1184 
1185         do
1186         {
1187           FT_Bool  is_serif;
1188 
1189 
1190           /* check for roundness of segment */
1191           if ( seg->flags & AF_EDGE_ROUND )
1192             is_round++;
1193           else
1194             is_straight++;
1195 
1196           /* check for links -- if seg->serif is set, then seg->link must */
1197           /* be ignored                                                   */
1198           is_serif = FT_BOOL( seg->serif && seg->serif->edge != edge );
1199 
1200           if ( seg->link || is_serif )
1201           {
1202             AF_Edge     edge2;
1203             AF_Segment  seg2;
1204 
1205 
1206             edge2 = edge->link;
1207             seg2  = seg->link;
1208 
1209             if ( is_serif )
1210             {
1211               seg2  = seg->serif;
1212               edge2 = edge->serif;
1213             }
1214 
1215             if ( edge2 )
1216             {
1217               FT_Pos  edge_delta;
1218               FT_Pos  seg_delta;
1219 
1220 
1221               edge_delta = edge->fpos - edge2->fpos;
1222               if ( edge_delta < 0 )
1223                 edge_delta = -edge_delta;
1224 
1225               seg_delta = AF_SEGMENT_DIST( seg, seg2 );
1226 
1227               if ( seg_delta < edge_delta )
1228                 edge2 = seg2->edge;
1229             }
1230             else
1231               edge2 = seg2->edge;
1232 
1233             if ( is_serif )
1234             {
1235               edge->serif   = edge2;
1236               edge2->flags |= AF_EDGE_SERIF;
1237             }
1238             else
1239               edge->link = edge2;
1240           }
1241 
1242           seg = seg->edge_next;
1243 
1244         } while ( seg != edge->first );
1245 
1246       Skip_Loop:
1247         /* set the round/straight flags */
1248         edge->flags = AF_EDGE_NORMAL;
1249 
1250         if ( is_round > 0 && is_round >= is_straight )
1251           edge->flags |= AF_EDGE_ROUND;
1252 
1253         /* get rid of serifs if link is set                 */
1254         /* XXX: This gets rid of many unpleasant artefacts! */
1255         /*      Example: the `c' in cour.pfa at size 13     */
1256 
1257         if ( edge->serif && edge->link )
1258           edge->serif = NULL;
1259       }
1260     }
1261 
1262   Exit:
1263     return error;
1264   }
1265 
1266 
1267   /* Detect segments and edges for given dimension. */
1268 
1269   static FT_Error
af_cjk_hints_detect_features(AF_GlyphHints hints,AF_Dimension dim)1270   af_cjk_hints_detect_features( AF_GlyphHints  hints,
1271                                 AF_Dimension   dim )
1272   {
1273     FT_Error  error;
1274 
1275 
1276     error = af_cjk_hints_compute_segments( hints, dim );
1277     if ( !error )
1278     {
1279       af_cjk_hints_link_segments( hints, dim );
1280 
1281       error = af_cjk_hints_compute_edges( hints, dim );
1282     }
1283     return error;
1284   }
1285 
1286 
1287   /* Compute all edges which lie within blue zones. */
1288 
1289   static void
af_cjk_hints_compute_blue_edges(AF_GlyphHints hints,AF_CJKMetrics metrics,AF_Dimension dim)1290   af_cjk_hints_compute_blue_edges( AF_GlyphHints  hints,
1291                                    AF_CJKMetrics  metrics,
1292                                    AF_Dimension   dim )
1293   {
1294     AF_AxisHints  axis       = &hints->axis[dim];
1295     AF_Edge       edge       = axis->edges;
1296     AF_Edge       edge_limit = FT_OFFSET( edge, axis->num_edges );
1297     AF_CJKAxis    cjk        = &metrics->axis[dim];
1298     FT_Fixed      scale      = cjk->scale;
1299     FT_Pos        best_dist0;  /* initial threshold */
1300 
1301 
1302     /* compute the initial threshold as a fraction of the EM size */
1303     best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
1304 
1305     if ( best_dist0 > 64 / 2 ) /* maximum 1/2 pixel */
1306       best_dist0 = 64 / 2;
1307 
1308     /* compute which blue zones are active, i.e. have their scaled */
1309     /* size < 3/4 pixels                                           */
1310 
1311     /* If the distant between an edge and a blue zone is shorter than */
1312     /* best_dist0, set the blue zone for the edge.  Then search for   */
1313     /* the blue zone with the smallest best_dist to the edge.         */
1314 
1315     for ( ; edge < edge_limit; edge++ )
1316     {
1317       FT_UInt   bb;
1318       AF_Width  best_blue = NULL;
1319       FT_Pos    best_dist = best_dist0;
1320 
1321 
1322       for ( bb = 0; bb < cjk->blue_count; bb++ )
1323       {
1324         AF_CJKBlue  blue = cjk->blues + bb;
1325         FT_Bool     is_top_right_blue, is_major_dir;
1326 
1327 
1328         /* skip inactive blue zones (i.e., those that are too small) */
1329         if ( !( blue->flags & AF_CJK_BLUE_ACTIVE ) )
1330           continue;
1331 
1332         /* if it is a top zone, check for right edges -- if it is a bottom */
1333         /* zone, check for left edges                                      */
1334         /*                                                                 */
1335         /* of course, that's for TrueType                                  */
1336         is_top_right_blue =
1337           (FT_Byte)( ( blue->flags & AF_CJK_BLUE_TOP ) != 0 );
1338         is_major_dir =
1339           FT_BOOL( edge->dir == axis->major_dir );
1340 
1341         /* if it is a top zone, the edge must be against the major    */
1342         /* direction; if it is a bottom zone, it must be in the major */
1343         /* direction                                                  */
1344         if ( is_top_right_blue ^ is_major_dir )
1345         {
1346           FT_Pos    dist;
1347           AF_Width  compare;
1348 
1349 
1350           /* Compare the edge to the closest blue zone type */
1351           if ( FT_ABS( edge->fpos - blue->ref.org ) >
1352                FT_ABS( edge->fpos - blue->shoot.org ) )
1353             compare = &blue->shoot;
1354           else
1355             compare = &blue->ref;
1356 
1357           dist = edge->fpos - compare->org;
1358           if ( dist < 0 )
1359             dist = -dist;
1360 
1361           dist = FT_MulFix( dist, scale );
1362           if ( dist < best_dist )
1363           {
1364             best_dist = dist;
1365             best_blue = compare;
1366           }
1367         }
1368       }
1369 
1370       if ( best_blue )
1371         edge->blue_edge = best_blue;
1372     }
1373   }
1374 
1375 
1376   /* Initalize hinting engine. */
1377 
1378   FT_LOCAL_DEF( FT_Error )
af_cjk_hints_init(AF_GlyphHints hints,AF_CJKMetrics metrics)1379   af_cjk_hints_init( AF_GlyphHints  hints,
1380                      AF_CJKMetrics  metrics )
1381   {
1382     FT_Render_Mode  mode;
1383     FT_UInt32       scaler_flags, other_flags;
1384 
1385 
1386     af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics );
1387 
1388     /*
1389      * correct x_scale and y_scale when needed, since they may have
1390      * been modified af_cjk_scale_dim above
1391      */
1392     hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
1393     hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
1394     hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
1395     hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
1396 
1397     /* compute flags depending on render mode, etc. */
1398     mode = metrics->root.scaler.render_mode;
1399 
1400     scaler_flags = hints->scaler_flags;
1401     other_flags  = 0;
1402 
1403     /*
1404      * We snap the width of vertical stems for the monochrome and
1405      * horizontal LCD rendering targets only.
1406      */
1407     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
1408       other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
1409 
1410     /*
1411      * We snap the width of horizontal stems for the monochrome and
1412      * vertical LCD rendering targets only.
1413      */
1414     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
1415       other_flags |= AF_LATIN_HINTS_VERT_SNAP;
1416 
1417     /*
1418      * We adjust stems to full pixels unless in `light' or `lcd' mode.
1419      */
1420     if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD )
1421       other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
1422 
1423     if ( mode == FT_RENDER_MODE_MONO )
1424       other_flags |= AF_LATIN_HINTS_MONO;
1425 
1426     scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE;
1427 
1428     hints->scaler_flags = scaler_flags;
1429     hints->other_flags  = other_flags;
1430 
1431     return FT_Err_Ok;
1432   }
1433 
1434 
1435   /*************************************************************************/
1436   /*************************************************************************/
1437   /*****                                                               *****/
1438   /*****          C J K   G L Y P H   G R I D - F I T T I N G          *****/
1439   /*****                                                               *****/
1440   /*************************************************************************/
1441   /*************************************************************************/
1442 
1443   /* Snap a given width in scaled coordinates to one of the */
1444   /* current standard widths.                               */
1445 
1446   static FT_Pos
af_cjk_snap_width(AF_Width widths,FT_UInt count,FT_Pos width)1447   af_cjk_snap_width( AF_Width  widths,
1448                      FT_UInt   count,
1449                      FT_Pos    width )
1450   {
1451     FT_UInt  n;
1452     FT_Pos   best      = 64 + 32 + 2;
1453     FT_Pos   reference = width;
1454     FT_Pos   scaled;
1455 
1456 
1457     for ( n = 0; n < count; n++ )
1458     {
1459       FT_Pos  w;
1460       FT_Pos  dist;
1461 
1462 
1463       w = widths[n].cur;
1464       dist = width - w;
1465       if ( dist < 0 )
1466         dist = -dist;
1467       if ( dist < best )
1468       {
1469         best      = dist;
1470         reference = w;
1471       }
1472     }
1473 
1474     scaled = FT_PIX_ROUND( reference );
1475 
1476     if ( width >= reference )
1477     {
1478       if ( width < scaled + 48 )
1479         width = reference;
1480     }
1481     else
1482     {
1483       if ( width > scaled - 48 )
1484         width = reference;
1485     }
1486 
1487     return width;
1488   }
1489 
1490 
1491   /* Compute the snapped width of a given stem.                          */
1492   /* There is a lot of voodoo in this function; changing the hard-coded  */
1493   /* parameters influence the whole hinting process.                     */
1494 
1495   static FT_Pos
af_cjk_compute_stem_width(AF_GlyphHints hints,AF_Dimension dim,FT_Pos width,FT_UInt base_flags,FT_UInt stem_flags)1496   af_cjk_compute_stem_width( AF_GlyphHints  hints,
1497                              AF_Dimension   dim,
1498                              FT_Pos         width,
1499                              FT_UInt        base_flags,
1500                              FT_UInt        stem_flags )
1501   {
1502     AF_CJKMetrics  metrics  = (AF_CJKMetrics)hints->metrics;
1503     AF_CJKAxis     axis     = &metrics->axis[dim];
1504     FT_Pos         dist     = width;
1505     FT_Int         sign     = 0;
1506     FT_Bool        vertical = FT_BOOL( dim == AF_DIMENSION_VERT );
1507 
1508     FT_UNUSED( base_flags );
1509     FT_UNUSED( stem_flags );
1510 
1511 
1512     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1513       return width;
1514 
1515     if ( dist < 0 )
1516     {
1517       dist = -width;
1518       sign = 1;
1519     }
1520 
1521     if ( (  vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
1522          ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
1523     {
1524       /* smooth hinting process: very lightly quantize the stem width */
1525 
1526       if ( axis->width_count > 0 )
1527       {
1528         if ( FT_ABS( dist - axis->widths[0].cur ) < 40 )
1529         {
1530           dist = axis->widths[0].cur;
1531           if ( dist < 48 )
1532             dist = 48;
1533 
1534           goto Done_Width;
1535         }
1536       }
1537 
1538       if ( dist < 54 )
1539         dist += ( 54 - dist ) / 2;
1540       else if ( dist < 3 * 64 )
1541       {
1542         FT_Pos  delta;
1543 
1544 
1545         delta  = dist & 63;
1546         dist  &= -64;
1547 
1548         if ( delta < 10 )
1549           dist += delta;
1550         else if ( delta < 22 )
1551           dist += 10;
1552         else if ( delta < 42 )
1553           dist += delta;
1554         else if ( delta < 54 )
1555           dist += 54;
1556         else
1557           dist += delta;
1558       }
1559     }
1560     else
1561     {
1562       /* strong hinting process: snap the stem width to integer pixels */
1563 
1564       dist = af_cjk_snap_width( axis->widths, axis->width_count, dist );
1565 
1566       if ( vertical )
1567       {
1568         /* in the case of vertical hinting, always round */
1569         /* the stem heights to integer pixels            */
1570 
1571         if ( dist >= 64 )
1572           dist = ( dist + 16 ) & ~63;
1573         else
1574           dist = 64;
1575       }
1576       else
1577       {
1578         if ( AF_LATIN_HINTS_DO_MONO( hints ) )
1579         {
1580           /* monochrome horizontal hinting: snap widths to integer pixels */
1581           /* with a different threshold                                   */
1582 
1583           if ( dist < 64 )
1584             dist = 64;
1585           else
1586             dist = ( dist + 32 ) & ~63;
1587         }
1588         else
1589         {
1590           /* for horizontal anti-aliased hinting, we adopt a more subtle */
1591           /* approach: we strengthen small stems, round stems whose size */
1592           /* is between 1 and 2 pixels to an integer, otherwise nothing  */
1593 
1594           if ( dist < 48 )
1595             dist = ( dist + 64 ) >> 1;
1596 
1597           else if ( dist < 128 )
1598             dist = ( dist + 22 ) & ~63;
1599           else
1600             /* round otherwise to prevent color fringes in LCD mode */
1601             dist = ( dist + 32 ) & ~63;
1602         }
1603       }
1604     }
1605 
1606   Done_Width:
1607     if ( sign )
1608       dist = -dist;
1609 
1610     return dist;
1611   }
1612 
1613 
1614   /* Align one stem edge relative to the previous stem edge. */
1615 
1616   static void
af_cjk_align_linked_edge(AF_GlyphHints hints,AF_Dimension dim,AF_Edge base_edge,AF_Edge stem_edge)1617   af_cjk_align_linked_edge( AF_GlyphHints  hints,
1618                             AF_Dimension   dim,
1619                             AF_Edge        base_edge,
1620                             AF_Edge        stem_edge )
1621   {
1622     FT_Pos  dist = stem_edge->opos - base_edge->opos;
1623 
1624     FT_Pos  fitted_width = af_cjk_compute_stem_width( hints, dim, dist,
1625                                                       base_edge->flags,
1626                                                       stem_edge->flags );
1627 
1628 
1629     stem_edge->pos = base_edge->pos + fitted_width;
1630 
1631     FT_TRACE5(( "  CJKLINK: edge %ld @%d (opos=%.2f) linked to %.2f,"
1632                 " dist was %.2f, now %.2f\n",
1633                 stem_edge - hints->axis[dim].edges, stem_edge->fpos,
1634                 (double)stem_edge->opos / 64,
1635                 (double)stem_edge->pos / 64,
1636                 (double)dist / 64,
1637                 (double)fitted_width / 64 ));
1638   }
1639 
1640 
1641   /* Shift the coordinates of the `serif' edge by the same amount */
1642   /* as the corresponding `base' edge has been moved already.     */
1643 
1644   static void
af_cjk_align_serif_edge(AF_GlyphHints hints,AF_Edge base,AF_Edge serif)1645   af_cjk_align_serif_edge( AF_GlyphHints  hints,
1646                            AF_Edge        base,
1647                            AF_Edge        serif )
1648   {
1649     FT_UNUSED( hints );
1650 
1651     serif->pos = base->pos + ( serif->opos - base->opos );
1652   }
1653 
1654 
1655   /*************************************************************************/
1656   /*************************************************************************/
1657   /*************************************************************************/
1658   /****                                                                 ****/
1659   /****                    E D G E   H I N T I N G                      ****/
1660   /****                                                                 ****/
1661   /*************************************************************************/
1662   /*************************************************************************/
1663   /*************************************************************************/
1664 
1665 
1666 #define AF_LIGHT_MODE_MAX_HORZ_GAP    9
1667 #define AF_LIGHT_MODE_MAX_VERT_GAP   15
1668 #define AF_LIGHT_MODE_MAX_DELTA_ABS  14
1669 
1670 
1671   static FT_Pos
af_hint_normal_stem(AF_GlyphHints hints,AF_Edge edge,AF_Edge edge2,FT_Pos anchor,AF_Dimension dim)1672   af_hint_normal_stem( AF_GlyphHints  hints,
1673                        AF_Edge        edge,
1674                        AF_Edge        edge2,
1675                        FT_Pos         anchor,
1676                        AF_Dimension   dim )
1677   {
1678     FT_Pos  org_len, cur_len, org_center;
1679     FT_Pos  cur_pos1, cur_pos2;
1680     FT_Pos  d_off1, u_off1, d_off2, u_off2, delta;
1681     FT_Pos  offset;
1682     FT_Pos  threshold = 64;
1683 
1684 
1685     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1686     {
1687       if ( ( edge->flags  & AF_EDGE_ROUND ) &&
1688            ( edge2->flags & AF_EDGE_ROUND ) )
1689       {
1690         if ( dim == AF_DIMENSION_VERT )
1691           threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP;
1692         else
1693           threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP;
1694       }
1695       else
1696       {
1697         if ( dim == AF_DIMENSION_VERT )
1698           threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3;
1699         else
1700           threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3;
1701       }
1702     }
1703 
1704     org_len    = edge2->opos - edge->opos;
1705     cur_len    = af_cjk_compute_stem_width( hints, dim, org_len,
1706                                             edge->flags,
1707                                             edge2->flags );
1708 
1709     org_center = ( edge->opos + edge2->opos ) / 2 + anchor;
1710     cur_pos1   = org_center - cur_len / 2;
1711     cur_pos2   = cur_pos1 + cur_len;
1712     d_off1     = cur_pos1 - FT_PIX_FLOOR( cur_pos1 );
1713     d_off2     = cur_pos2 - FT_PIX_FLOOR( cur_pos2 );
1714     u_off1     = 64 - d_off1;
1715     u_off2     = 64 - d_off2;
1716     delta      = 0;
1717 
1718 
1719     if ( d_off1 == 0 || d_off2 == 0 )
1720       goto Exit;
1721 
1722     if ( cur_len <= threshold )
1723     {
1724       if ( d_off2 < cur_len )
1725       {
1726         if ( u_off1 <= d_off2 )
1727           delta =  u_off1;
1728         else
1729           delta = -d_off2;
1730       }
1731 
1732       goto Exit;
1733     }
1734 
1735     if ( threshold < 64 )
1736     {
1737       if ( d_off1 >= threshold || u_off1 >= threshold ||
1738            d_off2 >= threshold || u_off2 >= threshold )
1739         goto Exit;
1740     }
1741 
1742     offset = cur_len & 63;
1743 
1744     if ( offset < 32 )
1745     {
1746       if ( u_off1 <= offset || d_off2 <= offset )
1747         goto Exit;
1748     }
1749     else
1750       offset = 64 - threshold;
1751 
1752     d_off1 = threshold - u_off1;
1753     u_off1 = u_off1    - offset;
1754     u_off2 = threshold - d_off2;
1755     d_off2 = d_off2    - offset;
1756 
1757     if ( d_off1 <= u_off1 )
1758       u_off1 = -d_off1;
1759 
1760     if ( d_off2 <= u_off2 )
1761       u_off2 = -d_off2;
1762 
1763     if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) )
1764       delta = u_off1;
1765     else
1766       delta = u_off2;
1767 
1768   Exit:
1769 
1770 #if 1
1771     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1772     {
1773       if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS )
1774         delta = AF_LIGHT_MODE_MAX_DELTA_ABS;
1775       else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS )
1776         delta = -AF_LIGHT_MODE_MAX_DELTA_ABS;
1777     }
1778 #endif
1779 
1780     cur_pos1 += delta;
1781 
1782     if ( edge->opos < edge2->opos )
1783     {
1784       edge->pos  = cur_pos1;
1785       edge2->pos = cur_pos1 + cur_len;
1786     }
1787     else
1788     {
1789       edge->pos  = cur_pos1 + cur_len;
1790       edge2->pos = cur_pos1;
1791     }
1792 
1793     return delta;
1794   }
1795 
1796 
1797   /* The main grid-fitting routine. */
1798 
1799   static void
af_cjk_hint_edges(AF_GlyphHints hints,AF_Dimension dim)1800   af_cjk_hint_edges( AF_GlyphHints  hints,
1801                      AF_Dimension   dim )
1802   {
1803     AF_AxisHints  axis       = &hints->axis[dim];
1804     AF_Edge       edges      = axis->edges;
1805     AF_Edge       edge_limit = FT_OFFSET( edges, axis->num_edges );
1806     FT_PtrDist    n_edges;
1807     AF_Edge       edge;
1808     AF_Edge       anchor   = NULL;
1809     FT_Pos        delta    = 0;
1810     FT_Int        skipped  = 0;
1811     FT_Bool       has_last_stem = FALSE;
1812     FT_Pos        last_stem_pos = 0;
1813 
1814 #ifdef FT_DEBUG_LEVEL_TRACE
1815     FT_UInt       num_actions = 0;
1816 #endif
1817 
1818 
1819     FT_TRACE5(( "cjk %s edge hinting (style `%s')\n",
1820                 dim == AF_DIMENSION_VERT ? "horizontal" : "vertical",
1821                 af_style_names[hints->metrics->style_class->style] ));
1822 
1823     /* we begin by aligning all stems relative to the blue zone */
1824 
1825     if ( AF_HINTS_DO_BLUES( hints ) )
1826     {
1827       for ( edge = edges; edge < edge_limit; edge++ )
1828       {
1829         AF_Width  blue;
1830         AF_Edge   edge1, edge2;
1831 
1832 
1833         if ( edge->flags & AF_EDGE_DONE )
1834           continue;
1835 
1836         blue  = edge->blue_edge;
1837         edge1 = NULL;
1838         edge2 = edge->link;
1839 
1840         if ( blue )
1841         {
1842           edge1 = edge;
1843         }
1844         else if ( edge2 && edge2->blue_edge )
1845         {
1846           blue  = edge2->blue_edge;
1847           edge1 = edge2;
1848           edge2 = edge;
1849         }
1850 
1851         if ( !edge1 )
1852           continue;
1853 
1854 #ifdef FT_DEBUG_LEVEL_TRACE
1855         FT_TRACE5(( "  CJKBLUE: edge %ld @%d (opos=%.2f) snapped to %.2f,"
1856                     " was %.2f\n",
1857                     edge1 - edges, edge1->fpos, (double)edge1->opos / 64,
1858                     (double)blue->fit / 64, (double)edge1->pos / 64 ));
1859 
1860         num_actions++;
1861 #endif
1862 
1863         edge1->pos    = blue->fit;
1864         edge1->flags |= AF_EDGE_DONE;
1865 
1866         if ( edge2 && !edge2->blue_edge )
1867         {
1868           af_cjk_align_linked_edge( hints, dim, edge1, edge2 );
1869           edge2->flags |= AF_EDGE_DONE;
1870 
1871 #ifdef FT_DEBUG_LEVEL_TRACE
1872           num_actions++;
1873 #endif
1874         }
1875 
1876         if ( !anchor )
1877           anchor = edge;
1878       }
1879     }
1880 
1881     /* now we align all stem edges. */
1882     for ( edge = edges; edge < edge_limit; edge++ )
1883     {
1884       AF_Edge  edge2;
1885 
1886 
1887       if ( edge->flags & AF_EDGE_DONE )
1888         continue;
1889 
1890       /* skip all non-stem edges */
1891       edge2 = edge->link;
1892       if ( !edge2 )
1893       {
1894         skipped++;
1895         continue;
1896       }
1897 
1898       /* Some CJK characters have so many stems that
1899        * the hinter is likely to merge two adjacent ones.
1900        * To solve this problem, if either edge of a stem
1901        * is too close to the previous one, we avoid
1902        * aligning the two edges, but rather interpolate
1903        * their locations at the end of this function in
1904        * order to preserve the space between the stems.
1905        */
1906       if ( has_last_stem                       &&
1907            ( edge->pos  < last_stem_pos + 64 ||
1908              edge2->pos < last_stem_pos + 64 ) )
1909       {
1910         skipped++;
1911         continue;
1912       }
1913 
1914       /* now align the stem */
1915 
1916       /* this should not happen, but it's better to be safe */
1917       if ( edge2->blue_edge )
1918       {
1919         FT_TRACE5(( "ASSERTION FAILED for edge %ld\n", edge2-edges ));
1920 
1921         af_cjk_align_linked_edge( hints, dim, edge2, edge );
1922         edge->flags |= AF_EDGE_DONE;
1923 
1924 #ifdef FT_DEBUG_LEVEL_TRACE
1925         num_actions++;
1926 #endif
1927 
1928         continue;
1929       }
1930 
1931       if ( edge2 < edge )
1932       {
1933         af_cjk_align_linked_edge( hints, dim, edge2, edge );
1934         edge->flags |= AF_EDGE_DONE;
1935 
1936 #ifdef FT_DEBUG_LEVEL_TRACE
1937         num_actions++;
1938 #endif
1939 
1940         /* We rarely reaches here it seems;
1941          * usually the two edges belonging
1942          * to one stem are marked as DONE together
1943          */
1944         has_last_stem = TRUE;
1945         last_stem_pos = edge->pos;
1946         continue;
1947       }
1948 
1949       if ( dim != AF_DIMENSION_VERT && !anchor )
1950       {
1951 
1952 #if 0
1953         if ( fixedpitch )
1954         {
1955           AF_Edge     left  = edge;
1956           AF_Edge     right = edge_limit - 1;
1957           AF_EdgeRec  left1, left2, right1, right2;
1958           FT_Pos      target, center1, center2;
1959           FT_Pos      delta1, delta2, d1, d2;
1960 
1961 
1962           while ( right > left && !right->link )
1963             right--;
1964 
1965           left1  = *left;
1966           left2  = *left->link;
1967           right1 = *right->link;
1968           right2 = *right;
1969 
1970           delta  = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2;
1971           target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16;
1972 
1973           delta1  = delta;
1974           delta1 += af_hint_normal_stem( hints, left, left->link,
1975                                          delta1, 0 );
1976 
1977           if ( left->link != right )
1978             af_hint_normal_stem( hints, right->link, right, delta1, 0 );
1979 
1980           center1 = left->pos + ( right->pos - left->pos ) / 2;
1981 
1982           if ( center1 >= target )
1983             delta2 = delta - 32;
1984           else
1985             delta2 = delta + 32;
1986 
1987           delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 );
1988 
1989           if ( delta1 != delta2 )
1990           {
1991             if ( left->link != right )
1992               af_hint_normal_stem( hints, &right1, &right2, delta2, 0 );
1993 
1994             center2 = left1.pos + ( right2.pos - left1.pos ) / 2;
1995 
1996             d1 = center1 - target;
1997             d2 = center2 - target;
1998 
1999             if ( FT_ABS( d2 ) < FT_ABS( d1 ) )
2000             {
2001               left->pos       = left1.pos;
2002               left->link->pos = left2.pos;
2003 
2004               if ( left->link != right )
2005               {
2006                 right->link->pos = right1.pos;
2007                 right->pos       = right2.pos;
2008               }
2009 
2010               delta1 = delta2;
2011             }
2012           }
2013 
2014           delta               = delta1;
2015           right->link->flags |= AF_EDGE_DONE;
2016           right->flags       |= AF_EDGE_DONE;
2017         }
2018         else
2019 
2020 #endif /* 0 */
2021 
2022           delta = af_hint_normal_stem( hints, edge, edge2, 0,
2023                                        AF_DIMENSION_HORZ );
2024       }
2025       else
2026         af_hint_normal_stem( hints, edge, edge2, delta, dim );
2027 
2028 #if 0
2029       printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n",
2030                edge - edges, edge2 - edges,
2031                (double)( edge->pos - edge->opos ) / 64,
2032                (double)( edge2->pos - edge2->opos ) / 64 );
2033 #endif
2034 
2035       anchor = edge;
2036       edge->flags  |= AF_EDGE_DONE;
2037       edge2->flags |= AF_EDGE_DONE;
2038       has_last_stem = TRUE;
2039       last_stem_pos = edge2->pos;
2040     }
2041 
2042     /* make sure that lowercase m's maintain their symmetry */
2043 
2044     /* In general, lowercase m's have six vertical edges if they are sans */
2045     /* serif, or twelve if they are with serifs.  This implementation is  */
2046     /* based on that assumption, and seems to work very well with most    */
2047     /* faces.  However, if for a certain face this assumption is not      */
2048     /* true, the m is just rendered like before.  In addition, any stem   */
2049     /* correction will only be applied to symmetrical glyphs (even if the */
2050     /* glyph is not an m), so the potential for unwanted distortion is    */
2051     /* relatively low.                                                    */
2052 
2053     /* We don't handle horizontal edges since we can't easily assure that */
2054     /* the third (lowest) stem aligns with the base line; it might end up */
2055     /* one pixel higher or lower.                                         */
2056 
2057     n_edges = edge_limit - edges;
2058     if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
2059     {
2060       AF_Edge  edge1, edge2, edge3;
2061       FT_Pos   dist1, dist2, span;
2062 
2063 
2064       if ( n_edges == 6 )
2065       {
2066         edge1 = edges;
2067         edge2 = edges + 2;
2068         edge3 = edges + 4;
2069       }
2070       else
2071       {
2072         edge1 = edges + 1;
2073         edge2 = edges + 5;
2074         edge3 = edges + 9;
2075       }
2076 
2077       dist1 = edge2->opos - edge1->opos;
2078       dist2 = edge3->opos - edge2->opos;
2079 
2080       span = dist1 - dist2;
2081       if ( span < 0 )
2082         span = -span;
2083 
2084       if ( edge1->link == edge1 + 1 &&
2085            edge2->link == edge2 + 1 &&
2086            edge3->link == edge3 + 1 && span < 8 )
2087       {
2088         delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
2089         edge3->pos -= delta;
2090         if ( edge3->link )
2091           edge3->link->pos -= delta;
2092 
2093         /* move the serifs along with the stem */
2094         if ( n_edges == 12 )
2095         {
2096           ( edges + 8 )->pos -= delta;
2097           ( edges + 11 )->pos -= delta;
2098         }
2099 
2100         edge3->flags |= AF_EDGE_DONE;
2101         if ( edge3->link )
2102           edge3->link->flags |= AF_EDGE_DONE;
2103       }
2104     }
2105 
2106     if ( !skipped )
2107       goto Exit;
2108 
2109     /*
2110      * now hint the remaining edges (serifs and single) in order
2111      * to complete our processing
2112      */
2113     for ( edge = edges; edge < edge_limit; edge++ )
2114     {
2115       if ( edge->flags & AF_EDGE_DONE )
2116         continue;
2117 
2118       if ( edge->serif )
2119       {
2120         af_cjk_align_serif_edge( hints, edge->serif, edge );
2121         edge->flags |= AF_EDGE_DONE;
2122         skipped--;
2123       }
2124     }
2125 
2126     if ( !skipped )
2127       goto Exit;
2128 
2129     for ( edge = edges; edge < edge_limit; edge++ )
2130     {
2131       AF_Edge  before, after;
2132 
2133 
2134       if ( edge->flags & AF_EDGE_DONE )
2135         continue;
2136 
2137       before = after = edge;
2138 
2139       while ( --before >= edges )
2140         if ( before->flags & AF_EDGE_DONE )
2141           break;
2142 
2143       while ( ++after < edge_limit )
2144         if ( after->flags & AF_EDGE_DONE )
2145           break;
2146 
2147       if ( before >= edges || after < edge_limit )
2148       {
2149         if ( before < edges )
2150           af_cjk_align_serif_edge( hints, after, edge );
2151         else if ( after >= edge_limit )
2152           af_cjk_align_serif_edge( hints, before, edge );
2153         else
2154         {
2155           if ( after->fpos == before->fpos )
2156             edge->pos = before->pos;
2157           else
2158             edge->pos = before->pos +
2159                         FT_MulDiv( edge->fpos - before->fpos,
2160                                    after->pos - before->pos,
2161                                    after->fpos - before->fpos );
2162         }
2163       }
2164     }
2165 
2166   Exit:
2167 
2168 #ifdef FT_DEBUG_LEVEL_TRACE
2169     if ( !num_actions )
2170       FT_TRACE5(( "  (none)\n" ));
2171     FT_TRACE5(( "\n" ));
2172 #endif
2173 
2174     return;
2175   }
2176 
2177 
2178   static void
af_cjk_align_edge_points(AF_GlyphHints hints,AF_Dimension dim)2179   af_cjk_align_edge_points( AF_GlyphHints  hints,
2180                             AF_Dimension   dim )
2181   {
2182     AF_AxisHints  axis       = & hints->axis[dim];
2183     AF_Edge       edges      = axis->edges;
2184     AF_Edge       edge_limit = FT_OFFSET( edges, axis->num_edges );
2185     AF_Edge       edge;
2186     FT_Bool       snapping;
2187 
2188 
2189     snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ             &&
2190                           AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) )  ||
2191                         ( dim == AF_DIMENSION_VERT             &&
2192                           AF_LATIN_HINTS_DO_VERT_SNAP( hints ) )  );
2193 
2194     for ( edge = edges; edge < edge_limit; edge++ )
2195     {
2196       /* move the points of each segment     */
2197       /* in each edge to the edge's position */
2198       AF_Segment  seg = edge->first;
2199 
2200 
2201       if ( snapping )
2202       {
2203         do
2204         {
2205           AF_Point  point = seg->first;
2206 
2207 
2208           for (;;)
2209           {
2210             if ( dim == AF_DIMENSION_HORZ )
2211             {
2212               point->x      = edge->pos;
2213               point->flags |= AF_FLAG_TOUCH_X;
2214             }
2215             else
2216             {
2217               point->y      = edge->pos;
2218               point->flags |= AF_FLAG_TOUCH_Y;
2219             }
2220 
2221             if ( point == seg->last )
2222               break;
2223 
2224             point = point->next;
2225           }
2226 
2227           seg = seg->edge_next;
2228 
2229         } while ( seg != edge->first );
2230       }
2231       else
2232       {
2233         FT_Pos  delta = edge->pos - edge->opos;
2234 
2235 
2236         do
2237         {
2238           AF_Point  point = seg->first;
2239 
2240 
2241           for (;;)
2242           {
2243             if ( dim == AF_DIMENSION_HORZ )
2244             {
2245               point->x     += delta;
2246               point->flags |= AF_FLAG_TOUCH_X;
2247             }
2248             else
2249             {
2250               point->y     += delta;
2251               point->flags |= AF_FLAG_TOUCH_Y;
2252             }
2253 
2254             if ( point == seg->last )
2255               break;
2256 
2257             point = point->next;
2258           }
2259 
2260           seg = seg->edge_next;
2261 
2262         } while ( seg != edge->first );
2263       }
2264     }
2265   }
2266 
2267 
2268   /* Apply the complete hinting algorithm to a CJK glyph. */
2269 
2270   FT_LOCAL_DEF( FT_Error )
af_cjk_hints_apply(FT_UInt glyph_index,AF_GlyphHints hints,FT_Outline * outline,AF_CJKMetrics metrics)2271   af_cjk_hints_apply( FT_UInt        glyph_index,
2272                       AF_GlyphHints  hints,
2273                       FT_Outline*    outline,
2274                       AF_CJKMetrics  metrics )
2275   {
2276     FT_Error  error;
2277     int       dim;
2278 
2279     FT_UNUSED( metrics );
2280     FT_UNUSED( glyph_index );
2281 
2282 
2283     error = af_glyph_hints_reload( hints, outline );
2284     if ( error )
2285       goto Exit;
2286 
2287     /* analyze glyph outline */
2288     if ( AF_HINTS_DO_HORIZONTAL( hints ) )
2289     {
2290       error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ );
2291       if ( error )
2292         goto Exit;
2293 
2294       af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_HORZ );
2295     }
2296 
2297     if ( AF_HINTS_DO_VERTICAL( hints ) )
2298     {
2299       error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
2300       if ( error )
2301         goto Exit;
2302 
2303       af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_VERT );
2304     }
2305 
2306     /* grid-fit the outline */
2307     for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
2308     {
2309       if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
2310            ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
2311       {
2312         af_cjk_hint_edges( hints, (AF_Dimension)dim );
2313         af_cjk_align_edge_points( hints, (AF_Dimension)dim );
2314         af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
2315         af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
2316       }
2317     }
2318 
2319     af_glyph_hints_save( hints, outline );
2320 
2321   Exit:
2322     return error;
2323   }
2324 
2325 
2326   /*************************************************************************/
2327   /*************************************************************************/
2328   /*****                                                               *****/
2329   /*****                C J K   S C R I P T   C L A S S                *****/
2330   /*****                                                               *****/
2331   /*************************************************************************/
2332   /*************************************************************************/
2333 
2334 
2335   AF_DEFINE_WRITING_SYSTEM_CLASS(
2336     af_cjk_writing_system_class,
2337 
2338     AF_WRITING_SYSTEM_CJK,
2339 
2340     sizeof ( AF_CJKMetricsRec ),
2341 
2342     (AF_WritingSystem_InitMetricsFunc) af_cjk_metrics_init,        /* style_metrics_init    */
2343     (AF_WritingSystem_ScaleMetricsFunc)af_cjk_metrics_scale,       /* style_metrics_scale   */
2344     (AF_WritingSystem_DoneMetricsFunc) NULL,                       /* style_metrics_done    */
2345     (AF_WritingSystem_GetStdWidthsFunc)af_cjk_get_standard_widths, /* style_metrics_getstdw */
2346 
2347     (AF_WritingSystem_InitHintsFunc)   af_cjk_hints_init,          /* style_hints_init      */
2348     (AF_WritingSystem_ApplyHintsFunc)  af_cjk_hints_apply          /* style_hints_apply     */
2349   )
2350 
2351 
2352 #else /* !AF_CONFIG_OPTION_CJK */
2353 
2354 
2355   AF_DEFINE_WRITING_SYSTEM_CLASS(
2356     af_cjk_writing_system_class,
2357 
2358     AF_WRITING_SYSTEM_CJK,
2359 
2360     sizeof ( AF_CJKMetricsRec ),
2361 
2362     (AF_WritingSystem_InitMetricsFunc) NULL, /* style_metrics_init    */
2363     (AF_WritingSystem_ScaleMetricsFunc)NULL, /* style_metrics_scale   */
2364     (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done    */
2365     (AF_WritingSystem_GetStdWidthsFunc)NULL, /* style_metrics_getstdw */
2366 
2367     (AF_WritingSystem_InitHintsFunc)   NULL, /* style_hints_init      */
2368     (AF_WritingSystem_ApplyHintsFunc)  NULL  /* style_hints_apply     */
2369   )
2370 
2371 
2372 #endif /* !AF_CONFIG_OPTION_CJK */
2373 
2374 
2375 /* END */
2376