xref: /aosp_15_r20/external/freetype/src/autofit/afcjk.c (revision 63949dbd25bcc50c4e1178497ff9e9574d44fc5a)
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  pp, first, last;
421 
422 
423           last = -1;
424           for ( nn = 0; nn < outline.n_contours; nn++ )
425           {
426             first = last + 1;
427             last  = outline.contours[nn];
428 
429             /* Avoid single-point contours since they are never rasterized. */
430             /* In some fonts, they correspond to mark attachment points     */
431             /* which are way outside of the glyph's real outline.           */
432             if ( last <= first )
433               continue;
434 
435             if ( AF_CJK_IS_HORIZ_BLUE( bs ) )
436             {
437               if ( AF_CJK_IS_RIGHT_BLUE( bs ) )
438               {
439                 for ( pp = first; pp <= last; pp++ )
440                   if ( best_point < 0 || points[pp].x > best_pos )
441                   {
442                     best_point = pp;
443                     best_pos   = points[pp].x;
444                   }
445               }
446               else
447               {
448                 for ( pp = first; pp <= last; pp++ )
449                   if ( best_point < 0 || points[pp].x < best_pos )
450                   {
451                     best_point = pp;
452                     best_pos   = points[pp].x;
453                   }
454               }
455             }
456             else
457             {
458               if ( AF_CJK_IS_TOP_BLUE( bs ) )
459               {
460                 for ( pp = first; pp <= last; pp++ )
461                   if ( best_point < 0 || points[pp].y > best_pos )
462                   {
463                     best_point = pp;
464                     best_pos   = points[pp].y;
465                   }
466               }
467               else
468               {
469                 for ( pp = first; pp <= last; pp++ )
470                   if ( best_point < 0 || points[pp].y < best_pos )
471                   {
472                     best_point = pp;
473                     best_pos   = points[pp].y;
474                   }
475               }
476             }
477           }
478 
479           FT_TRACE5(( "  U+%04lX: best_pos = %5ld\n", ch, best_pos ));
480         }
481 
482         if ( fill )
483           fills[num_fills++] = best_pos;
484         else
485           flats[num_flats++] = best_pos;
486 
487       } /* end while loop */
488 
489       if ( num_flats == 0 && num_fills == 0 )
490       {
491         /*
492          * we couldn't find a single glyph to compute this blue zone,
493          * we will simply ignore it then
494          */
495         FT_TRACE5(( "  empty\n" ));
496         continue;
497       }
498 
499       /* we have computed the contents of the `fill' and `flats' tables,   */
500       /* now determine the reference and overshoot position of the blue -- */
501       /* we simply take the median value after a simple sort               */
502       af_sort_pos( num_fills, fills );
503       af_sort_pos( num_flats, flats );
504 
505       blue       = &axis->blues[axis->blue_count];
506       blue_ref   = &blue->ref.org;
507       blue_shoot = &blue->shoot.org;
508 
509       axis->blue_count++;
510 
511       if ( num_flats == 0 )
512       {
513         *blue_ref   =
514         *blue_shoot = fills[num_fills / 2];
515       }
516       else if ( num_fills == 0 )
517       {
518         *blue_ref   =
519         *blue_shoot = flats[num_flats / 2];
520       }
521       else
522       {
523         *blue_ref   = fills[num_fills / 2];
524         *blue_shoot = flats[num_flats / 2];
525       }
526 
527       /* make sure blue_ref >= blue_shoot for top/right or */
528       /* vice versa for bottom/left                        */
529       if ( *blue_shoot != *blue_ref )
530       {
531         FT_Pos   ref       = *blue_ref;
532         FT_Pos   shoot     = *blue_shoot;
533         FT_Bool  under_ref = FT_BOOL( shoot < ref );
534 
535 
536         /* AF_CJK_IS_TOP_BLUE covers `right' and `top' */
537         if ( AF_CJK_IS_TOP_BLUE( bs ) ^ under_ref )
538         {
539           *blue_ref   =
540           *blue_shoot = ( shoot + ref ) / 2;
541 
542           FT_TRACE5(( "  [reference smaller than overshoot,"
543                       " taking mean value]\n" ));
544         }
545       }
546 
547       blue->flags = 0;
548       if ( AF_CJK_IS_TOP_BLUE( bs ) )
549         blue->flags |= AF_CJK_BLUE_TOP;
550 
551       FT_TRACE5(( "    -> reference = %ld\n", *blue_ref ));
552       FT_TRACE5(( "       overshoot = %ld\n", *blue_shoot ));
553 
554     } /* end for loop */
555 
556     af_shaper_buf_destroy( face, shaper_buf );
557 
558     FT_TRACE5(( "\n" ));
559 
560     return;
561   }
562 
563 
564   /* Basically the Latin version with type AF_CJKMetrics for metrics. */
565 
566   FT_LOCAL_DEF( void )
af_cjk_metrics_check_digits(AF_CJKMetrics metrics,FT_Face face)567   af_cjk_metrics_check_digits( AF_CJKMetrics  metrics,
568                                FT_Face        face )
569   {
570     FT_Bool  started = 0, same_width = 1;
571     FT_Long  advance = 0, old_advance = 0;
572 
573     /* If HarfBuzz is not available, we need a pointer to a single */
574     /* unsigned long value.                                        */
575 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
576     void*     shaper_buf;
577 #else
578     FT_ULong  shaper_buf_;
579     void*     shaper_buf = &shaper_buf_;
580 #endif
581 
582     /* in all supported charmaps, digits have character codes 0x30-0x39 */
583     const char   digits[] = "0 1 2 3 4 5 6 7 8 9";
584     const char*  p;
585 
586 
587     p = digits;
588 
589 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
590     shaper_buf = af_shaper_buf_create( face );
591 #endif
592 
593     while ( *p )
594     {
595       FT_ULong      glyph_index;
596       unsigned int  num_idx;
597 
598 
599       /* reject input that maps to more than a single glyph */
600       p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
601       if ( num_idx > 1 )
602         continue;
603 
604       glyph_index = af_shaper_get_elem( &metrics->root,
605                                         shaper_buf,
606                                         0,
607                                         &advance,
608                                         NULL );
609       if ( !glyph_index )
610         continue;
611 
612       if ( started )
613       {
614         if ( advance != old_advance )
615         {
616           same_width = 0;
617           break;
618         }
619       }
620       else
621       {
622         old_advance = advance;
623         started     = 1;
624       }
625     }
626 
627     af_shaper_buf_destroy( face, shaper_buf );
628 
629     metrics->root.digits_have_same_width = same_width;
630   }
631 
632 
633   /* Initialize global metrics. */
634 
635   FT_LOCAL_DEF( FT_Error )
af_cjk_metrics_init(AF_StyleMetrics metrics_,FT_Face face)636   af_cjk_metrics_init( AF_StyleMetrics  metrics_,  /* AF_CJKMetrics */
637                        FT_Face          face )
638   {
639     AF_CJKMetrics  metrics = (AF_CJKMetrics)metrics_;
640     FT_CharMap     oldmap  = face->charmap;
641 
642 
643     metrics->units_per_em = face->units_per_EM;
644 
645     if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
646     {
647       af_cjk_metrics_init_widths( metrics, face );
648       af_cjk_metrics_init_blues( metrics, face );
649       af_cjk_metrics_check_digits( metrics, face );
650     }
651 
652     face->charmap = oldmap;
653     return FT_Err_Ok;
654   }
655 
656 
657   /* Adjust scaling value, then scale and shift widths   */
658   /* and blue zones (if applicable) for given dimension. */
659 
660   static void
af_cjk_metrics_scale_dim(AF_CJKMetrics metrics,AF_Scaler scaler,AF_Dimension dim)661   af_cjk_metrics_scale_dim( AF_CJKMetrics  metrics,
662                             AF_Scaler      scaler,
663                             AF_Dimension   dim )
664   {
665     FT_Fixed    scale;
666     FT_Pos      delta;
667     AF_CJKAxis  axis;
668     FT_UInt     nn;
669 
670 
671     if ( dim == AF_DIMENSION_HORZ )
672     {
673       scale = scaler->x_scale;
674       delta = scaler->x_delta;
675     }
676     else
677     {
678       scale = scaler->y_scale;
679       delta = scaler->y_delta;
680     }
681 
682     axis = &metrics->axis[dim];
683 
684     if ( axis->org_scale == scale && axis->org_delta == delta )
685       return;
686 
687     axis->org_scale = scale;
688     axis->org_delta = delta;
689 
690     axis->scale = scale;
691     axis->delta = delta;
692 
693     /* scale the blue zones */
694     for ( nn = 0; nn < axis->blue_count; nn++ )
695     {
696       AF_CJKBlue  blue = &axis->blues[nn];
697       FT_Pos      dist;
698 
699 
700       blue->ref.cur   = FT_MulFix( blue->ref.org, scale ) + delta;
701       blue->ref.fit   = blue->ref.cur;
702       blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
703       blue->shoot.fit = blue->shoot.cur;
704       blue->flags    &= ~AF_CJK_BLUE_ACTIVE;
705 
706       /* a blue zone is only active if it is less than 3/4 pixels tall */
707       dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
708       if ( dist <= 48 && dist >= -48 )
709       {
710         FT_Pos  delta1, delta2;
711 
712 
713         blue->ref.fit  = FT_PIX_ROUND( blue->ref.cur );
714 
715         /* shoot is under shoot for cjk */
716         delta1 = FT_DivFix( blue->ref.fit, scale ) - blue->shoot.org;
717         delta2 = delta1;
718         if ( delta1 < 0 )
719           delta2 = -delta2;
720 
721         delta2 = FT_MulFix( delta2, scale );
722 
723         FT_TRACE5(( "delta: %ld", delta1 ));
724         if ( delta2 < 32 )
725           delta2 = 0;
726 #if 0
727         else if ( delta2 < 64 )
728           delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
729 #endif
730         else
731           delta2 = FT_PIX_ROUND( delta2 );
732         FT_TRACE5(( "/%ld\n", delta2 ));
733 
734         if ( delta1 < 0 )
735           delta2 = -delta2;
736 
737         blue->shoot.fit = blue->ref.fit - delta2;
738 
739         FT_TRACE5(( ">> active cjk blue zone %c%d[%ld/%ld]:\n",
740                     ( dim == AF_DIMENSION_HORZ ) ? 'H' : 'V',
741                     nn, blue->ref.org, blue->shoot.org ));
742         FT_TRACE5(( "     ref:   cur=%.2f fit=%.2f\n",
743                     (double)blue->ref.cur / 64,
744                     (double)blue->ref.fit / 64 ));
745         FT_TRACE5(( "     shoot: cur=%.2f fit=%.2f\n",
746                     (double)blue->shoot.cur / 64,
747                     (double)blue->shoot.fit / 64 ));
748 
749         blue->flags |= AF_CJK_BLUE_ACTIVE;
750       }
751     }
752   }
753 
754 
755   /* Scale global values in both directions. */
756 
757   FT_LOCAL_DEF( void )
af_cjk_metrics_scale(AF_StyleMetrics metrics_,AF_Scaler scaler)758   af_cjk_metrics_scale( AF_StyleMetrics  metrics_,   /* AF_CJKMetrics */
759                         AF_Scaler        scaler )
760   {
761     AF_CJKMetrics  metrics = (AF_CJKMetrics)metrics_;
762 
763 
764     /* we copy the whole structure since the x and y scaling values */
765     /* are not modified, contrary to e.g. the `latin' auto-hinter   */
766     metrics->root.scaler = *scaler;
767 
768     af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
769     af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
770   }
771 
772 
773   /* Extract standard_width from writing system/script specific */
774   /* metrics class.                                             */
775 
776   FT_CALLBACK_DEF( void )
af_cjk_get_standard_widths(AF_StyleMetrics metrics_,FT_Pos * stdHW,FT_Pos * stdVW)777   af_cjk_get_standard_widths( AF_StyleMetrics  metrics_,  /* AF_CJKMetrics */
778                               FT_Pos*          stdHW,
779                               FT_Pos*          stdVW )
780   {
781     AF_CJKMetrics  metrics = (AF_CJKMetrics)metrics_;
782 
783 
784     if ( stdHW )
785       *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width;
786 
787     if ( stdVW )
788       *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width;
789   }
790 
791 
792   /*************************************************************************/
793   /*************************************************************************/
794   /*****                                                               *****/
795   /*****              C J K   G L Y P H   A N A L Y S I S              *****/
796   /*****                                                               *****/
797   /*************************************************************************/
798   /*************************************************************************/
799 
800 
801   /* Walk over all contours and compute its segments. */
802 
803   static FT_Error
af_cjk_hints_compute_segments(AF_GlyphHints hints,AF_Dimension dim)804   af_cjk_hints_compute_segments( AF_GlyphHints  hints,
805                                  AF_Dimension   dim )
806   {
807     AF_AxisHints  axis          = &hints->axis[dim];
808     AF_Segment    segments      = axis->segments;
809     AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
810     FT_Error      error;
811     AF_Segment    seg;
812 
813 
814     error = af_latin_hints_compute_segments( hints, dim );
815     if ( error )
816       return error;
817 
818     /* a segment is round if it doesn't have successive */
819     /* on-curve points.                                 */
820     for ( seg = segments; seg < segment_limit; seg++ )
821     {
822       AF_Point  pt   = seg->first;
823       AF_Point  last = seg->last;
824       FT_UInt   f0   = pt->flags & AF_FLAG_CONTROL;
825       FT_UInt   f1;
826 
827 
828       seg->flags &= ~AF_EDGE_ROUND;
829 
830       for ( ; pt != last; f0 = f1 )
831       {
832         pt = pt->next;
833         f1 = pt->flags & AF_FLAG_CONTROL;
834 
835         if ( !f0 && !f1 )
836           break;
837 
838         if ( pt == last )
839           seg->flags |= AF_EDGE_ROUND;
840       }
841     }
842 
843     return FT_Err_Ok;
844   }
845 
846 
847   static void
af_cjk_hints_link_segments(AF_GlyphHints hints,AF_Dimension dim)848   af_cjk_hints_link_segments( AF_GlyphHints  hints,
849                               AF_Dimension   dim )
850   {
851     AF_AxisHints  axis          = &hints->axis[dim];
852     AF_Segment    segments      = axis->segments;
853     AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
854     AF_Direction  major_dir     = axis->major_dir;
855     AF_Segment    seg1, seg2;
856     FT_Pos        len_threshold;
857     FT_Pos        dist_threshold;
858 
859 
860     len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
861 
862     dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
863                                                   : hints->y_scale;
864     dist_threshold = FT_DivFix( 64 * 3, dist_threshold );
865 
866     /* now compare each segment to the others */
867     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
868     {
869       if ( seg1->dir != major_dir )
870         continue;
871 
872       for ( seg2 = segments; seg2 < segment_limit; seg2++ )
873         if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
874         {
875           FT_Pos  dist = seg2->pos - seg1->pos;
876 
877 
878           if ( dist < 0 )
879             continue;
880 
881           {
882             FT_Pos  min = seg1->min_coord;
883             FT_Pos  max = seg1->max_coord;
884             FT_Pos  len;
885 
886 
887             if ( min < seg2->min_coord )
888               min = seg2->min_coord;
889 
890             if ( max > seg2->max_coord )
891               max = seg2->max_coord;
892 
893             len = max - min;
894             if ( len >= len_threshold )
895             {
896               if ( dist * 8 < seg1->score * 9                        &&
897                    ( dist * 8 < seg1->score * 7 || seg1->len < len ) )
898               {
899                 seg1->score = dist;
900                 seg1->len   = len;
901                 seg1->link  = seg2;
902               }
903 
904               if ( dist * 8 < seg2->score * 9                        &&
905                    ( dist * 8 < seg2->score * 7 || seg2->len < len ) )
906               {
907                 seg2->score = dist;
908                 seg2->len   = len;
909                 seg2->link  = seg1;
910               }
911             }
912           }
913         }
914     }
915 
916     /*
917      * now compute the `serif' segments
918      *
919      * In Hanzi, some strokes are wider on one or both of the ends.
920      * We either identify the stems on the ends as serifs or remove
921      * the linkage, depending on the length of the stems.
922      *
923      */
924 
925     {
926       AF_Segment  link1, link2;
927 
928 
929       for ( seg1 = segments; seg1 < segment_limit; seg1++ )
930       {
931         link1 = seg1->link;
932         if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos )
933           continue;
934 
935         if ( seg1->score >= dist_threshold )
936           continue;
937 
938         for ( seg2 = segments; seg2 < segment_limit; seg2++ )
939         {
940           if ( seg2->pos > seg1->pos || seg1 == seg2 )
941             continue;
942 
943           link2 = seg2->link;
944           if ( !link2 || link2->link != seg2 || link2->pos < link1->pos )
945             continue;
946 
947           if ( seg1->pos == seg2->pos && link1->pos == link2->pos )
948             continue;
949 
950           if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score )
951             continue;
952 
953           /* seg2 < seg1 < link1 < link2 */
954 
955           if ( seg1->len >= seg2->len * 3 )
956           {
957             AF_Segment  seg;
958 
959 
960             for ( seg = segments; seg < segment_limit; seg++ )
961             {
962               AF_Segment  link = seg->link;
963 
964 
965               if ( link == seg2 )
966               {
967                 seg->link  = NULL;
968                 seg->serif = link1;
969               }
970               else if ( link == link2 )
971               {
972                 seg->link  = NULL;
973                 seg->serif = seg1;
974               }
975             }
976           }
977           else
978           {
979             seg1->link = link1->link = NULL;
980 
981             break;
982           }
983         }
984       }
985     }
986 
987     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
988     {
989       seg2 = seg1->link;
990 
991       if ( seg2 )
992       {
993         if ( seg2->link != seg1 )
994         {
995           seg1->link = NULL;
996 
997           if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 )
998             seg1->serif = seg2->link;
999         }
1000       }
1001     }
1002   }
1003 
1004 
1005   static FT_Error
af_cjk_hints_compute_edges(AF_GlyphHints hints,AF_Dimension dim)1006   af_cjk_hints_compute_edges( AF_GlyphHints  hints,
1007                               AF_Dimension   dim )
1008   {
1009     AF_AxisHints  axis   = &hints->axis[dim];
1010     FT_Error      error  = FT_Err_Ok;
1011     FT_Memory     memory = hints->memory;
1012     AF_CJKAxis    laxis  = &((AF_CJKMetrics)hints->metrics)->axis[dim];
1013 
1014     AF_Segment    segments      = axis->segments;
1015     AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
1016     AF_Segment    seg;
1017 
1018     FT_Fixed      scale;
1019     FT_Pos        edge_distance_threshold;
1020 
1021 
1022     axis->num_edges = 0;
1023 
1024     scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
1025                                          : hints->y_scale;
1026 
1027     /**********************************************************************
1028      *
1029      * We begin by generating a sorted table of edges for the current
1030      * direction.  To do so, we simply scan each segment and try to find
1031      * an edge in our table that corresponds to its position.
1032      *
1033      * If no edge is found, we create and insert a new edge in the
1034      * sorted table.  Otherwise, we simply add the segment to the edge's
1035      * list which is then processed in the second step to compute the
1036      * edge's properties.
1037      *
1038      * Note that the edges table is sorted along the segment/edge
1039      * position.
1040      *
1041      */
1042 
1043     edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
1044                                          scale );
1045     if ( edge_distance_threshold > 64 / 4 )
1046       edge_distance_threshold = FT_DivFix( 64 / 4, scale );
1047     else
1048       edge_distance_threshold = laxis->edge_distance_threshold;
1049 
1050     for ( seg = segments; seg < segment_limit; seg++ )
1051     {
1052       AF_Edge  found = NULL;
1053       FT_Pos   best  = 0xFFFFU;
1054       FT_UInt  ee;
1055 
1056 
1057       /* look for an edge corresponding to the segment */
1058       for ( ee = 0; ee < axis->num_edges; ee++ )
1059       {
1060         AF_Edge  edge = axis->edges + ee;
1061         FT_Pos   dist;
1062 
1063 
1064         if ( edge->dir != seg->dir )
1065           continue;
1066 
1067         dist = seg->pos - edge->fpos;
1068         if ( dist < 0 )
1069           dist = -dist;
1070 
1071         if ( dist < edge_distance_threshold && dist < best )
1072         {
1073           AF_Segment  link = seg->link;
1074 
1075 
1076           /* check whether all linked segments of the candidate edge */
1077           /* can make a single edge.                                 */
1078           if ( link )
1079           {
1080             AF_Segment  seg1  = edge->first;
1081             FT_Pos      dist2 = 0;
1082 
1083 
1084             do
1085             {
1086               AF_Segment  link1 = seg1->link;
1087 
1088 
1089               if ( link1 )
1090               {
1091                 dist2 = AF_SEGMENT_DIST( link, link1 );
1092                 if ( dist2 >= edge_distance_threshold )
1093                   break;
1094               }
1095 
1096             } while ( ( seg1 = seg1->edge_next ) != edge->first );
1097 
1098             if ( dist2 >= edge_distance_threshold )
1099               continue;
1100           }
1101 
1102           best  = dist;
1103           found = edge;
1104         }
1105       }
1106 
1107       if ( !found )
1108       {
1109         AF_Edge  edge;
1110 
1111 
1112         /* insert a new edge in the list and */
1113         /* sort according to the position    */
1114         error = af_axis_hints_new_edge( axis, seg->pos,
1115                                         (AF_Direction)seg->dir, 0,
1116                                         memory, &edge );
1117         if ( error )
1118           goto Exit;
1119 
1120         /* add the segment to the new edge's list */
1121         FT_ZERO( edge );
1122 
1123         edge->first    = seg;
1124         edge->last     = seg;
1125         edge->dir      = seg->dir;
1126         edge->fpos     = seg->pos;
1127         edge->opos     = FT_MulFix( seg->pos, scale );
1128         edge->pos      = edge->opos;
1129         seg->edge_next = seg;
1130       }
1131       else
1132       {
1133         /* if an edge was found, simply add the segment to the edge's */
1134         /* list                                                       */
1135         seg->edge_next         = found->first;
1136         found->last->edge_next = seg;
1137         found->last            = seg;
1138       }
1139     }
1140 
1141     /*******************************************************************
1142      *
1143      * Good, we now compute each edge's properties according to the
1144      * segments found on its position.  Basically, these are
1145      *
1146      * - the edge's main direction
1147      * - stem edge, serif edge or both (which defaults to stem then)
1148      * - rounded edge, straight or both (which defaults to straight)
1149      * - link for edge
1150      *
1151      */
1152 
1153     /* first of all, set the `edge' field in each segment -- this is */
1154     /* required in order to compute edge links                       */
1155 
1156     /*
1157      * Note that removing this loop and setting the `edge' field of each
1158      * segment directly in the code above slows down execution speed for
1159      * some reasons on platforms like the Sun.
1160      */
1161     {
1162       AF_Edge  edges      = axis->edges;
1163       AF_Edge  edge_limit = FT_OFFSET( edges, axis->num_edges );
1164       AF_Edge  edge;
1165 
1166 
1167       for ( edge = edges; edge < edge_limit; edge++ )
1168       {
1169         seg = edge->first;
1170         if ( seg )
1171           do
1172           {
1173             seg->edge = edge;
1174             seg       = seg->edge_next;
1175 
1176           } while ( seg != edge->first );
1177       }
1178 
1179       /* now compute each edge properties */
1180       for ( edge = edges; edge < edge_limit; edge++ )
1181       {
1182         FT_Int  is_round    = 0;  /* does it contain round segments?    */
1183         FT_Int  is_straight = 0;  /* does it contain straight segments? */
1184 
1185 
1186         seg = edge->first;
1187         if ( !seg )
1188           goto Skip_Loop;
1189 
1190         do
1191         {
1192           FT_Bool  is_serif;
1193 
1194 
1195           /* check for roundness of segment */
1196           if ( seg->flags & AF_EDGE_ROUND )
1197             is_round++;
1198           else
1199             is_straight++;
1200 
1201           /* check for links -- if seg->serif is set, then seg->link must */
1202           /* be ignored                                                   */
1203           is_serif = FT_BOOL( seg->serif && seg->serif->edge != edge );
1204 
1205           if ( seg->link || is_serif )
1206           {
1207             AF_Edge     edge2;
1208             AF_Segment  seg2;
1209 
1210 
1211             edge2 = edge->link;
1212             seg2  = seg->link;
1213 
1214             if ( is_serif )
1215             {
1216               seg2  = seg->serif;
1217               edge2 = edge->serif;
1218             }
1219 
1220             if ( edge2 )
1221             {
1222               FT_Pos  edge_delta;
1223               FT_Pos  seg_delta;
1224 
1225 
1226               edge_delta = edge->fpos - edge2->fpos;
1227               if ( edge_delta < 0 )
1228                 edge_delta = -edge_delta;
1229 
1230               seg_delta = AF_SEGMENT_DIST( seg, seg2 );
1231 
1232               if ( seg_delta < edge_delta )
1233                 edge2 = seg2->edge;
1234             }
1235             else
1236               edge2 = seg2->edge;
1237 
1238             if ( is_serif )
1239             {
1240               edge->serif   = edge2;
1241               edge2->flags |= AF_EDGE_SERIF;
1242             }
1243             else
1244               edge->link = edge2;
1245           }
1246 
1247           seg = seg->edge_next;
1248 
1249         } while ( seg != edge->first );
1250 
1251       Skip_Loop:
1252         /* set the round/straight flags */
1253         edge->flags = AF_EDGE_NORMAL;
1254 
1255         if ( is_round > 0 && is_round >= is_straight )
1256           edge->flags |= AF_EDGE_ROUND;
1257 
1258         /* get rid of serifs if link is set                 */
1259         /* XXX: This gets rid of many unpleasant artefacts! */
1260         /*      Example: the `c' in cour.pfa at size 13     */
1261 
1262         if ( edge->serif && edge->link )
1263           edge->serif = NULL;
1264       }
1265     }
1266 
1267   Exit:
1268     return error;
1269   }
1270 
1271 
1272   /* Detect segments and edges for given dimension. */
1273 
1274   static FT_Error
af_cjk_hints_detect_features(AF_GlyphHints hints,AF_Dimension dim)1275   af_cjk_hints_detect_features( AF_GlyphHints  hints,
1276                                 AF_Dimension   dim )
1277   {
1278     FT_Error  error;
1279 
1280 
1281     error = af_cjk_hints_compute_segments( hints, dim );
1282     if ( !error )
1283     {
1284       af_cjk_hints_link_segments( hints, dim );
1285 
1286       error = af_cjk_hints_compute_edges( hints, dim );
1287     }
1288     return error;
1289   }
1290 
1291 
1292   /* Compute all edges which lie within blue zones. */
1293 
1294   static void
af_cjk_hints_compute_blue_edges(AF_GlyphHints hints,AF_CJKMetrics metrics,AF_Dimension dim)1295   af_cjk_hints_compute_blue_edges( AF_GlyphHints  hints,
1296                                    AF_CJKMetrics  metrics,
1297                                    AF_Dimension   dim )
1298   {
1299     AF_AxisHints  axis       = &hints->axis[dim];
1300     AF_Edge       edge       = axis->edges;
1301     AF_Edge       edge_limit = FT_OFFSET( edge, axis->num_edges );
1302     AF_CJKAxis    cjk        = &metrics->axis[dim];
1303     FT_Fixed      scale      = cjk->scale;
1304     FT_Pos        best_dist0;  /* initial threshold */
1305 
1306 
1307     /* compute the initial threshold as a fraction of the EM size */
1308     best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
1309 
1310     if ( best_dist0 > 64 / 2 ) /* maximum 1/2 pixel */
1311       best_dist0 = 64 / 2;
1312 
1313     /* compute which blue zones are active, i.e. have their scaled */
1314     /* size < 3/4 pixels                                           */
1315 
1316     /* If the distant between an edge and a blue zone is shorter than */
1317     /* best_dist0, set the blue zone for the edge.  Then search for   */
1318     /* the blue zone with the smallest best_dist to the edge.         */
1319 
1320     for ( ; edge < edge_limit; edge++ )
1321     {
1322       FT_UInt   bb;
1323       AF_Width  best_blue = NULL;
1324       FT_Pos    best_dist = best_dist0;
1325 
1326 
1327       for ( bb = 0; bb < cjk->blue_count; bb++ )
1328       {
1329         AF_CJKBlue  blue = cjk->blues + bb;
1330         FT_Bool     is_top_right_blue, is_major_dir;
1331 
1332 
1333         /* skip inactive blue zones (i.e., those that are too small) */
1334         if ( !( blue->flags & AF_CJK_BLUE_ACTIVE ) )
1335           continue;
1336 
1337         /* if it is a top zone, check for right edges -- if it is a bottom */
1338         /* zone, check for left edges                                      */
1339         /*                                                                 */
1340         /* of course, that's for TrueType                                  */
1341         is_top_right_blue =
1342           (FT_Byte)( ( blue->flags & AF_CJK_BLUE_TOP ) != 0 );
1343         is_major_dir =
1344           FT_BOOL( edge->dir == axis->major_dir );
1345 
1346         /* if it is a top zone, the edge must be against the major    */
1347         /* direction; if it is a bottom zone, it must be in the major */
1348         /* direction                                                  */
1349         if ( is_top_right_blue ^ is_major_dir )
1350         {
1351           FT_Pos    dist;
1352           AF_Width  compare;
1353 
1354 
1355           /* Compare the edge to the closest blue zone type */
1356           if ( FT_ABS( edge->fpos - blue->ref.org ) >
1357                FT_ABS( edge->fpos - blue->shoot.org ) )
1358             compare = &blue->shoot;
1359           else
1360             compare = &blue->ref;
1361 
1362           dist = edge->fpos - compare->org;
1363           if ( dist < 0 )
1364             dist = -dist;
1365 
1366           dist = FT_MulFix( dist, scale );
1367           if ( dist < best_dist )
1368           {
1369             best_dist = dist;
1370             best_blue = compare;
1371           }
1372         }
1373       }
1374 
1375       if ( best_blue )
1376         edge->blue_edge = best_blue;
1377     }
1378   }
1379 
1380 
1381   /* Initalize hinting engine. */
1382 
1383   FT_LOCAL_DEF( FT_Error )
af_cjk_hints_init(AF_GlyphHints hints,AF_StyleMetrics metrics_)1384   af_cjk_hints_init( AF_GlyphHints    hints,
1385                      AF_StyleMetrics  metrics_ )   /* AF_CJKMetrics */
1386   {
1387     AF_CJKMetrics   metrics = (AF_CJKMetrics)metrics_;
1388     FT_Render_Mode  mode;
1389     FT_UInt32       scaler_flags, other_flags;
1390 
1391 
1392     af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics );
1393 
1394     /*
1395      * correct x_scale and y_scale when needed, since they may have
1396      * been modified af_cjk_scale_dim above
1397      */
1398     hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
1399     hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
1400     hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
1401     hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
1402 
1403     /* compute flags depending on render mode, etc. */
1404     mode = metrics->root.scaler.render_mode;
1405 
1406     scaler_flags = hints->scaler_flags;
1407     other_flags  = 0;
1408 
1409     /*
1410      * We snap the width of vertical stems for the monochrome and
1411      * horizontal LCD rendering targets only.
1412      */
1413     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
1414       other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
1415 
1416     /*
1417      * We snap the width of horizontal stems for the monochrome and
1418      * vertical LCD rendering targets only.
1419      */
1420     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
1421       other_flags |= AF_LATIN_HINTS_VERT_SNAP;
1422 
1423     /*
1424      * We adjust stems to full pixels unless in `light' or `lcd' mode.
1425      */
1426     if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD )
1427       other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
1428 
1429     if ( mode == FT_RENDER_MODE_MONO )
1430       other_flags |= AF_LATIN_HINTS_MONO;
1431 
1432     scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE;
1433 
1434     hints->scaler_flags = scaler_flags;
1435     hints->other_flags  = other_flags;
1436 
1437     return FT_Err_Ok;
1438   }
1439 
1440 
1441   /*************************************************************************/
1442   /*************************************************************************/
1443   /*****                                                               *****/
1444   /*****          C J K   G L Y P H   G R I D - F I T T I N G          *****/
1445   /*****                                                               *****/
1446   /*************************************************************************/
1447   /*************************************************************************/
1448 
1449   /* Snap a given width in scaled coordinates to one of the */
1450   /* current standard widths.                               */
1451 
1452   static FT_Pos
af_cjk_snap_width(AF_Width widths,FT_UInt count,FT_Pos width)1453   af_cjk_snap_width( AF_Width  widths,
1454                      FT_UInt   count,
1455                      FT_Pos    width )
1456   {
1457     FT_UInt  n;
1458     FT_Pos   best      = 64 + 32 + 2;
1459     FT_Pos   reference = width;
1460     FT_Pos   scaled;
1461 
1462 
1463     for ( n = 0; n < count; n++ )
1464     {
1465       FT_Pos  w;
1466       FT_Pos  dist;
1467 
1468 
1469       w = widths[n].cur;
1470       dist = width - w;
1471       if ( dist < 0 )
1472         dist = -dist;
1473       if ( dist < best )
1474       {
1475         best      = dist;
1476         reference = w;
1477       }
1478     }
1479 
1480     scaled = FT_PIX_ROUND( reference );
1481 
1482     if ( width >= reference )
1483     {
1484       if ( width < scaled + 48 )
1485         width = reference;
1486     }
1487     else
1488     {
1489       if ( width > scaled - 48 )
1490         width = reference;
1491     }
1492 
1493     return width;
1494   }
1495 
1496 
1497   /* Compute the snapped width of a given stem.                          */
1498   /* There is a lot of voodoo in this function; changing the hard-coded  */
1499   /* parameters influence the whole hinting process.                     */
1500 
1501   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)1502   af_cjk_compute_stem_width( AF_GlyphHints  hints,
1503                              AF_Dimension   dim,
1504                              FT_Pos         width,
1505                              FT_UInt        base_flags,
1506                              FT_UInt        stem_flags )
1507   {
1508     AF_CJKMetrics  metrics  = (AF_CJKMetrics)hints->metrics;
1509     AF_CJKAxis     axis     = &metrics->axis[dim];
1510     FT_Pos         dist     = width;
1511     FT_Int         sign     = 0;
1512     FT_Bool        vertical = FT_BOOL( dim == AF_DIMENSION_VERT );
1513 
1514     FT_UNUSED( base_flags );
1515     FT_UNUSED( stem_flags );
1516 
1517 
1518     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1519       return width;
1520 
1521     if ( dist < 0 )
1522     {
1523       dist = -width;
1524       sign = 1;
1525     }
1526 
1527     if ( (  vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
1528          ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
1529     {
1530       /* smooth hinting process: very lightly quantize the stem width */
1531 
1532       if ( axis->width_count > 0 )
1533       {
1534         if ( FT_ABS( dist - axis->widths[0].cur ) < 40 )
1535         {
1536           dist = axis->widths[0].cur;
1537           if ( dist < 48 )
1538             dist = 48;
1539 
1540           goto Done_Width;
1541         }
1542       }
1543 
1544       if ( dist < 54 )
1545         dist += ( 54 - dist ) / 2;
1546       else if ( dist < 3 * 64 )
1547       {
1548         FT_Pos  delta;
1549 
1550 
1551         delta  = dist & 63;
1552         dist  &= -64;
1553 
1554         if ( delta < 10 )
1555           dist += delta;
1556         else if ( delta < 22 )
1557           dist += 10;
1558         else if ( delta < 42 )
1559           dist += delta;
1560         else if ( delta < 54 )
1561           dist += 54;
1562         else
1563           dist += delta;
1564       }
1565     }
1566     else
1567     {
1568       /* strong hinting process: snap the stem width to integer pixels */
1569 
1570       dist = af_cjk_snap_width( axis->widths, axis->width_count, dist );
1571 
1572       if ( vertical )
1573       {
1574         /* in the case of vertical hinting, always round */
1575         /* the stem heights to integer pixels            */
1576 
1577         if ( dist >= 64 )
1578           dist = ( dist + 16 ) & ~63;
1579         else
1580           dist = 64;
1581       }
1582       else
1583       {
1584         if ( AF_LATIN_HINTS_DO_MONO( hints ) )
1585         {
1586           /* monochrome horizontal hinting: snap widths to integer pixels */
1587           /* with a different threshold                                   */
1588 
1589           if ( dist < 64 )
1590             dist = 64;
1591           else
1592             dist = ( dist + 32 ) & ~63;
1593         }
1594         else
1595         {
1596           /* for horizontal anti-aliased hinting, we adopt a more subtle */
1597           /* approach: we strengthen small stems, round stems whose size */
1598           /* is between 1 and 2 pixels to an integer, otherwise nothing  */
1599 
1600           if ( dist < 48 )
1601             dist = ( dist + 64 ) >> 1;
1602 
1603           else if ( dist < 128 )
1604             dist = ( dist + 22 ) & ~63;
1605           else
1606             /* round otherwise to prevent color fringes in LCD mode */
1607             dist = ( dist + 32 ) & ~63;
1608         }
1609       }
1610     }
1611 
1612   Done_Width:
1613     if ( sign )
1614       dist = -dist;
1615 
1616     return dist;
1617   }
1618 
1619 
1620   /* Align one stem edge relative to the previous stem edge. */
1621 
1622   static void
af_cjk_align_linked_edge(AF_GlyphHints hints,AF_Dimension dim,AF_Edge base_edge,AF_Edge stem_edge)1623   af_cjk_align_linked_edge( AF_GlyphHints  hints,
1624                             AF_Dimension   dim,
1625                             AF_Edge        base_edge,
1626                             AF_Edge        stem_edge )
1627   {
1628     FT_Pos  dist = stem_edge->opos - base_edge->opos;
1629 
1630     FT_Pos  fitted_width = af_cjk_compute_stem_width( hints, dim, dist,
1631                                                       base_edge->flags,
1632                                                       stem_edge->flags );
1633 
1634 
1635     stem_edge->pos = base_edge->pos + fitted_width;
1636 
1637     FT_TRACE5(( "  CJKLINK: edge %td @%d (opos=%.2f) linked to %.2f,"
1638                 " dist was %.2f, now %.2f\n",
1639                 stem_edge - hints->axis[dim].edges, stem_edge->fpos,
1640                 (double)stem_edge->opos / 64,
1641                 (double)stem_edge->pos / 64,
1642                 (double)dist / 64,
1643                 (double)fitted_width / 64 ));
1644   }
1645 
1646 
1647   /* Shift the coordinates of the `serif' edge by the same amount */
1648   /* as the corresponding `base' edge has been moved already.     */
1649 
1650   static void
af_cjk_align_serif_edge(AF_GlyphHints hints,AF_Edge base,AF_Edge serif)1651   af_cjk_align_serif_edge( AF_GlyphHints  hints,
1652                            AF_Edge        base,
1653                            AF_Edge        serif )
1654   {
1655     FT_UNUSED( hints );
1656 
1657     serif->pos = base->pos + ( serif->opos - base->opos );
1658   }
1659 
1660 
1661   /*************************************************************************/
1662   /*************************************************************************/
1663   /*************************************************************************/
1664   /****                                                                 ****/
1665   /****                    E D G E   H I N T I N G                      ****/
1666   /****                                                                 ****/
1667   /*************************************************************************/
1668   /*************************************************************************/
1669   /*************************************************************************/
1670 
1671 
1672 #define AF_LIGHT_MODE_MAX_HORZ_GAP    9
1673 #define AF_LIGHT_MODE_MAX_VERT_GAP   15
1674 #define AF_LIGHT_MODE_MAX_DELTA_ABS  14
1675 
1676 
1677   static FT_Pos
af_hint_normal_stem(AF_GlyphHints hints,AF_Edge edge,AF_Edge edge2,FT_Pos anchor,AF_Dimension dim)1678   af_hint_normal_stem( AF_GlyphHints  hints,
1679                        AF_Edge        edge,
1680                        AF_Edge        edge2,
1681                        FT_Pos         anchor,
1682                        AF_Dimension   dim )
1683   {
1684     FT_Pos  org_len, cur_len, org_center;
1685     FT_Pos  cur_pos1, cur_pos2;
1686     FT_Pos  d_off1, u_off1, d_off2, u_off2, delta;
1687     FT_Pos  offset;
1688     FT_Pos  threshold = 64;
1689 
1690 
1691     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1692     {
1693       if ( ( edge->flags  & AF_EDGE_ROUND ) &&
1694            ( edge2->flags & AF_EDGE_ROUND ) )
1695       {
1696         if ( dim == AF_DIMENSION_VERT )
1697           threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP;
1698         else
1699           threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP;
1700       }
1701       else
1702       {
1703         if ( dim == AF_DIMENSION_VERT )
1704           threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3;
1705         else
1706           threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3;
1707       }
1708     }
1709 
1710     org_len    = edge2->opos - edge->opos;
1711     cur_len    = af_cjk_compute_stem_width( hints, dim, org_len,
1712                                             edge->flags,
1713                                             edge2->flags );
1714 
1715     org_center = ( edge->opos + edge2->opos ) / 2 + anchor;
1716     cur_pos1   = org_center - cur_len / 2;
1717     cur_pos2   = cur_pos1 + cur_len;
1718     d_off1     = cur_pos1 - FT_PIX_FLOOR( cur_pos1 );
1719     d_off2     = cur_pos2 - FT_PIX_FLOOR( cur_pos2 );
1720     u_off1     = 64 - d_off1;
1721     u_off2     = 64 - d_off2;
1722     delta      = 0;
1723 
1724 
1725     if ( d_off1 == 0 || d_off2 == 0 )
1726       goto Exit;
1727 
1728     if ( cur_len <= threshold )
1729     {
1730       if ( d_off2 < cur_len )
1731       {
1732         if ( u_off1 <= d_off2 )
1733           delta =  u_off1;
1734         else
1735           delta = -d_off2;
1736       }
1737 
1738       goto Exit;
1739     }
1740 
1741     if ( threshold < 64 )
1742     {
1743       if ( d_off1 >= threshold || u_off1 >= threshold ||
1744            d_off2 >= threshold || u_off2 >= threshold )
1745         goto Exit;
1746     }
1747 
1748     offset = cur_len & 63;
1749 
1750     if ( offset < 32 )
1751     {
1752       if ( u_off1 <= offset || d_off2 <= offset )
1753         goto Exit;
1754     }
1755     else
1756       offset = 64 - threshold;
1757 
1758     d_off1 = threshold - u_off1;
1759     u_off1 = u_off1    - offset;
1760     u_off2 = threshold - d_off2;
1761     d_off2 = d_off2    - offset;
1762 
1763     if ( d_off1 <= u_off1 )
1764       u_off1 = -d_off1;
1765 
1766     if ( d_off2 <= u_off2 )
1767       u_off2 = -d_off2;
1768 
1769     if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) )
1770       delta = u_off1;
1771     else
1772       delta = u_off2;
1773 
1774   Exit:
1775 
1776 #if 1
1777     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1778     {
1779       if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS )
1780         delta = AF_LIGHT_MODE_MAX_DELTA_ABS;
1781       else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS )
1782         delta = -AF_LIGHT_MODE_MAX_DELTA_ABS;
1783     }
1784 #endif
1785 
1786     cur_pos1 += delta;
1787 
1788     if ( edge->opos < edge2->opos )
1789     {
1790       edge->pos  = cur_pos1;
1791       edge2->pos = cur_pos1 + cur_len;
1792     }
1793     else
1794     {
1795       edge->pos  = cur_pos1 + cur_len;
1796       edge2->pos = cur_pos1;
1797     }
1798 
1799     return delta;
1800   }
1801 
1802 
1803   /* The main grid-fitting routine. */
1804 
1805   static void
af_cjk_hint_edges(AF_GlyphHints hints,AF_Dimension dim)1806   af_cjk_hint_edges( AF_GlyphHints  hints,
1807                      AF_Dimension   dim )
1808   {
1809     AF_AxisHints  axis       = &hints->axis[dim];
1810     AF_Edge       edges      = axis->edges;
1811     AF_Edge       edge_limit = FT_OFFSET( edges, axis->num_edges );
1812     FT_PtrDist    n_edges;
1813     AF_Edge       edge;
1814     AF_Edge       anchor   = NULL;
1815     FT_Pos        delta    = 0;
1816     FT_Int        skipped  = 0;
1817     FT_Bool       has_last_stem = FALSE;
1818     FT_Pos        last_stem_pos = 0;
1819 
1820 #ifdef FT_DEBUG_LEVEL_TRACE
1821     FT_UInt       num_actions = 0;
1822 #endif
1823 
1824 
1825     FT_TRACE5(( "cjk %s edge hinting (style `%s')\n",
1826                 dim == AF_DIMENSION_VERT ? "horizontal" : "vertical",
1827                 af_style_names[hints->metrics->style_class->style] ));
1828 
1829     /* we begin by aligning all stems relative to the blue zone */
1830 
1831     if ( AF_HINTS_DO_BLUES( hints ) )
1832     {
1833       for ( edge = edges; edge < edge_limit; edge++ )
1834       {
1835         AF_Width  blue;
1836         AF_Edge   edge1, edge2;
1837 
1838 
1839         if ( edge->flags & AF_EDGE_DONE )
1840           continue;
1841 
1842         blue  = edge->blue_edge;
1843         edge1 = NULL;
1844         edge2 = edge->link;
1845 
1846         if ( blue )
1847         {
1848           edge1 = edge;
1849         }
1850         else if ( edge2 && edge2->blue_edge )
1851         {
1852           blue  = edge2->blue_edge;
1853           edge1 = edge2;
1854           edge2 = edge;
1855         }
1856 
1857         if ( !edge1 )
1858           continue;
1859 
1860 #ifdef FT_DEBUG_LEVEL_TRACE
1861         FT_TRACE5(( "  CJKBLUE: edge %td @%d (opos=%.2f) snapped to %.2f,"
1862                     " was %.2f\n",
1863                     edge1 - edges, edge1->fpos, (double)edge1->opos / 64,
1864                     (double)blue->fit / 64, (double)edge1->pos / 64 ));
1865 
1866         num_actions++;
1867 #endif
1868 
1869         edge1->pos    = blue->fit;
1870         edge1->flags |= AF_EDGE_DONE;
1871 
1872         if ( edge2 && !edge2->blue_edge )
1873         {
1874           af_cjk_align_linked_edge( hints, dim, edge1, edge2 );
1875           edge2->flags |= AF_EDGE_DONE;
1876 
1877 #ifdef FT_DEBUG_LEVEL_TRACE
1878           num_actions++;
1879 #endif
1880         }
1881 
1882         if ( !anchor )
1883           anchor = edge;
1884       }
1885     }
1886 
1887     /* now we align all stem edges. */
1888     for ( edge = edges; edge < edge_limit; edge++ )
1889     {
1890       AF_Edge  edge2;
1891 
1892 
1893       if ( edge->flags & AF_EDGE_DONE )
1894         continue;
1895 
1896       /* skip all non-stem edges */
1897       edge2 = edge->link;
1898       if ( !edge2 )
1899       {
1900         skipped++;
1901         continue;
1902       }
1903 
1904       /* Some CJK characters have so many stems that
1905        * the hinter is likely to merge two adjacent ones.
1906        * To solve this problem, if either edge of a stem
1907        * is too close to the previous one, we avoid
1908        * aligning the two edges, but rather interpolate
1909        * their locations at the end of this function in
1910        * order to preserve the space between the stems.
1911        */
1912       if ( has_last_stem                       &&
1913            ( edge->pos  < last_stem_pos + 64 ||
1914              edge2->pos < last_stem_pos + 64 ) )
1915       {
1916         skipped++;
1917         continue;
1918       }
1919 
1920       /* now align the stem */
1921 
1922       /* this should not happen, but it's better to be safe */
1923       if ( edge2->blue_edge )
1924       {
1925         FT_TRACE5(( "ASSERTION FAILED for edge %td\n", edge2 - edges ));
1926 
1927         af_cjk_align_linked_edge( hints, dim, edge2, edge );
1928         edge->flags |= AF_EDGE_DONE;
1929 
1930 #ifdef FT_DEBUG_LEVEL_TRACE
1931         num_actions++;
1932 #endif
1933 
1934         continue;
1935       }
1936 
1937       if ( edge2 < edge )
1938       {
1939         af_cjk_align_linked_edge( hints, dim, edge2, edge );
1940         edge->flags |= AF_EDGE_DONE;
1941 
1942 #ifdef FT_DEBUG_LEVEL_TRACE
1943         num_actions++;
1944 #endif
1945 
1946         /* We rarely reaches here it seems;
1947          * usually the two edges belonging
1948          * to one stem are marked as DONE together
1949          */
1950         has_last_stem = TRUE;
1951         last_stem_pos = edge->pos;
1952         continue;
1953       }
1954 
1955       if ( dim != AF_DIMENSION_VERT && !anchor )
1956       {
1957 
1958 #if 0
1959         if ( fixedpitch )
1960         {
1961           AF_Edge     left  = edge;
1962           AF_Edge     right = edge_limit - 1;
1963           AF_EdgeRec  left1, left2, right1, right2;
1964           FT_Pos      target, center1, center2;
1965           FT_Pos      delta1, delta2, d1, d2;
1966 
1967 
1968           while ( right > left && !right->link )
1969             right--;
1970 
1971           left1  = *left;
1972           left2  = *left->link;
1973           right1 = *right->link;
1974           right2 = *right;
1975 
1976           delta  = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2;
1977           target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16;
1978 
1979           delta1  = delta;
1980           delta1 += af_hint_normal_stem( hints, left, left->link,
1981                                          delta1, 0 );
1982 
1983           if ( left->link != right )
1984             af_hint_normal_stem( hints, right->link, right, delta1, 0 );
1985 
1986           center1 = left->pos + ( right->pos - left->pos ) / 2;
1987 
1988           if ( center1 >= target )
1989             delta2 = delta - 32;
1990           else
1991             delta2 = delta + 32;
1992 
1993           delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 );
1994 
1995           if ( delta1 != delta2 )
1996           {
1997             if ( left->link != right )
1998               af_hint_normal_stem( hints, &right1, &right2, delta2, 0 );
1999 
2000             center2 = left1.pos + ( right2.pos - left1.pos ) / 2;
2001 
2002             d1 = center1 - target;
2003             d2 = center2 - target;
2004 
2005             if ( FT_ABS( d2 ) < FT_ABS( d1 ) )
2006             {
2007               left->pos       = left1.pos;
2008               left->link->pos = left2.pos;
2009 
2010               if ( left->link != right )
2011               {
2012                 right->link->pos = right1.pos;
2013                 right->pos       = right2.pos;
2014               }
2015 
2016               delta1 = delta2;
2017             }
2018           }
2019 
2020           delta               = delta1;
2021           right->link->flags |= AF_EDGE_DONE;
2022           right->flags       |= AF_EDGE_DONE;
2023         }
2024         else
2025 
2026 #endif /* 0 */
2027 
2028           delta = af_hint_normal_stem( hints, edge, edge2, 0,
2029                                        AF_DIMENSION_HORZ );
2030       }
2031       else
2032         af_hint_normal_stem( hints, edge, edge2, delta, dim );
2033 
2034 #if 0
2035       printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n",
2036                edge - edges, edge2 - edges,
2037                (double)( edge->pos - edge->opos ) / 64,
2038                (double)( edge2->pos - edge2->opos ) / 64 );
2039 #endif
2040 
2041       anchor = edge;
2042       edge->flags  |= AF_EDGE_DONE;
2043       edge2->flags |= AF_EDGE_DONE;
2044       has_last_stem = TRUE;
2045       last_stem_pos = edge2->pos;
2046     }
2047 
2048     /* make sure that lowercase m's maintain their symmetry */
2049 
2050     /* In general, lowercase m's have six vertical edges if they are sans */
2051     /* serif, or twelve if they are with serifs.  This implementation is  */
2052     /* based on that assumption, and seems to work very well with most    */
2053     /* faces.  However, if for a certain face this assumption is not      */
2054     /* true, the m is just rendered like before.  In addition, any stem   */
2055     /* correction will only be applied to symmetrical glyphs (even if the */
2056     /* glyph is not an m), so the potential for unwanted distortion is    */
2057     /* relatively low.                                                    */
2058 
2059     /* We don't handle horizontal edges since we can't easily assure that */
2060     /* the third (lowest) stem aligns with the base line; it might end up */
2061     /* one pixel higher or lower.                                         */
2062 
2063     n_edges = edge_limit - edges;
2064     if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
2065     {
2066       AF_Edge  edge1, edge2, edge3;
2067       FT_Pos   dist1, dist2, span;
2068 
2069 
2070       if ( n_edges == 6 )
2071       {
2072         edge1 = edges;
2073         edge2 = edges + 2;
2074         edge3 = edges + 4;
2075       }
2076       else
2077       {
2078         edge1 = edges + 1;
2079         edge2 = edges + 5;
2080         edge3 = edges + 9;
2081       }
2082 
2083       dist1 = edge2->opos - edge1->opos;
2084       dist2 = edge3->opos - edge2->opos;
2085 
2086       span = dist1 - dist2;
2087       if ( span < 0 )
2088         span = -span;
2089 
2090       if ( edge1->link == edge1 + 1 &&
2091            edge2->link == edge2 + 1 &&
2092            edge3->link == edge3 + 1 && span < 8 )
2093       {
2094         delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
2095         edge3->pos -= delta;
2096         if ( edge3->link )
2097           edge3->link->pos -= delta;
2098 
2099         /* move the serifs along with the stem */
2100         if ( n_edges == 12 )
2101         {
2102           ( edges + 8 )->pos -= delta;
2103           ( edges + 11 )->pos -= delta;
2104         }
2105 
2106         edge3->flags |= AF_EDGE_DONE;
2107         if ( edge3->link )
2108           edge3->link->flags |= AF_EDGE_DONE;
2109       }
2110     }
2111 
2112     if ( !skipped )
2113       goto Exit;
2114 
2115     /*
2116      * now hint the remaining edges (serifs and single) in order
2117      * to complete our processing
2118      */
2119     for ( edge = edges; edge < edge_limit; edge++ )
2120     {
2121       if ( edge->flags & AF_EDGE_DONE )
2122         continue;
2123 
2124       if ( edge->serif )
2125       {
2126         af_cjk_align_serif_edge( hints, edge->serif, edge );
2127         edge->flags |= AF_EDGE_DONE;
2128         skipped--;
2129       }
2130     }
2131 
2132     if ( !skipped )
2133       goto Exit;
2134 
2135     for ( edge = edges; edge < edge_limit; edge++ )
2136     {
2137       AF_Edge  before, after;
2138 
2139 
2140       if ( edge->flags & AF_EDGE_DONE )
2141         continue;
2142 
2143       before = after = edge;
2144 
2145       while ( --before >= edges )
2146         if ( before->flags & AF_EDGE_DONE )
2147           break;
2148 
2149       while ( ++after < edge_limit )
2150         if ( after->flags & AF_EDGE_DONE )
2151           break;
2152 
2153       if ( before >= edges || after < edge_limit )
2154       {
2155         if ( before < edges )
2156           af_cjk_align_serif_edge( hints, after, edge );
2157         else if ( after >= edge_limit )
2158           af_cjk_align_serif_edge( hints, before, edge );
2159         else
2160         {
2161           if ( after->fpos == before->fpos )
2162             edge->pos = before->pos;
2163           else
2164             edge->pos = before->pos +
2165                         FT_MulDiv( edge->fpos - before->fpos,
2166                                    after->pos - before->pos,
2167                                    after->fpos - before->fpos );
2168         }
2169       }
2170     }
2171 
2172   Exit:
2173 
2174 #ifdef FT_DEBUG_LEVEL_TRACE
2175     if ( !num_actions )
2176       FT_TRACE5(( "  (none)\n" ));
2177     FT_TRACE5(( "\n" ));
2178 #endif
2179 
2180     return;
2181   }
2182 
2183 
2184   static void
af_cjk_align_edge_points(AF_GlyphHints hints,AF_Dimension dim)2185   af_cjk_align_edge_points( AF_GlyphHints  hints,
2186                             AF_Dimension   dim )
2187   {
2188     AF_AxisHints  axis       = & hints->axis[dim];
2189     AF_Edge       edges      = axis->edges;
2190     AF_Edge       edge_limit = FT_OFFSET( edges, axis->num_edges );
2191     AF_Edge       edge;
2192     FT_Bool       snapping;
2193 
2194 
2195     snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ             &&
2196                           AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) )  ||
2197                         ( dim == AF_DIMENSION_VERT             &&
2198                           AF_LATIN_HINTS_DO_VERT_SNAP( hints ) )  );
2199 
2200     for ( edge = edges; edge < edge_limit; edge++ )
2201     {
2202       /* move the points of each segment     */
2203       /* in each edge to the edge's position */
2204       AF_Segment  seg = edge->first;
2205 
2206 
2207       if ( snapping )
2208       {
2209         do
2210         {
2211           AF_Point  point = seg->first;
2212 
2213 
2214           for (;;)
2215           {
2216             if ( dim == AF_DIMENSION_HORZ )
2217             {
2218               point->x      = edge->pos;
2219               point->flags |= AF_FLAG_TOUCH_X;
2220             }
2221             else
2222             {
2223               point->y      = edge->pos;
2224               point->flags |= AF_FLAG_TOUCH_Y;
2225             }
2226 
2227             if ( point == seg->last )
2228               break;
2229 
2230             point = point->next;
2231           }
2232 
2233           seg = seg->edge_next;
2234 
2235         } while ( seg != edge->first );
2236       }
2237       else
2238       {
2239         FT_Pos  delta = edge->pos - edge->opos;
2240 
2241 
2242         do
2243         {
2244           AF_Point  point = seg->first;
2245 
2246 
2247           for (;;)
2248           {
2249             if ( dim == AF_DIMENSION_HORZ )
2250             {
2251               point->x     += delta;
2252               point->flags |= AF_FLAG_TOUCH_X;
2253             }
2254             else
2255             {
2256               point->y     += delta;
2257               point->flags |= AF_FLAG_TOUCH_Y;
2258             }
2259 
2260             if ( point == seg->last )
2261               break;
2262 
2263             point = point->next;
2264           }
2265 
2266           seg = seg->edge_next;
2267 
2268         } while ( seg != edge->first );
2269       }
2270     }
2271   }
2272 
2273 
2274   /* Apply the complete hinting algorithm to a CJK glyph. */
2275 
2276   FT_LOCAL_DEF( FT_Error )
af_cjk_hints_apply(FT_UInt glyph_index,AF_GlyphHints hints,FT_Outline * outline,AF_StyleMetrics metrics_)2277   af_cjk_hints_apply( FT_UInt          glyph_index,
2278                       AF_GlyphHints    hints,
2279                       FT_Outline*      outline,
2280                       AF_StyleMetrics  metrics_ )   /* AF_CJKMetrics */
2281   {
2282     AF_CJKMetrics  metrics = (AF_CJKMetrics)metrics_;
2283 
2284     FT_Error  error;
2285     int       dim;
2286 
2287     FT_UNUSED( metrics );
2288     FT_UNUSED( glyph_index );
2289 
2290 
2291     error = af_glyph_hints_reload( hints, outline );
2292     if ( error )
2293       goto Exit;
2294 
2295     /* analyze glyph outline */
2296     if ( AF_HINTS_DO_HORIZONTAL( hints ) )
2297     {
2298       error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ );
2299       if ( error )
2300         goto Exit;
2301 
2302       af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_HORZ );
2303     }
2304 
2305     if ( AF_HINTS_DO_VERTICAL( hints ) )
2306     {
2307       error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
2308       if ( error )
2309         goto Exit;
2310 
2311       af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_VERT );
2312     }
2313 
2314     /* grid-fit the outline */
2315     for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
2316     {
2317       if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
2318            ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
2319       {
2320         af_cjk_hint_edges( hints, (AF_Dimension)dim );
2321         af_cjk_align_edge_points( hints, (AF_Dimension)dim );
2322         af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
2323         af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
2324       }
2325     }
2326 
2327     af_glyph_hints_save( hints, outline );
2328 
2329   Exit:
2330     return error;
2331   }
2332 
2333 
2334   /*************************************************************************/
2335   /*************************************************************************/
2336   /*****                                                               *****/
2337   /*****                C J K   S C R I P T   C L A S S                *****/
2338   /*****                                                               *****/
2339   /*************************************************************************/
2340   /*************************************************************************/
2341 
2342 
2343   AF_DEFINE_WRITING_SYSTEM_CLASS(
2344     af_cjk_writing_system_class,
2345 
2346     AF_WRITING_SYSTEM_CJK,
2347 
2348     sizeof ( AF_CJKMetricsRec ),
2349 
2350     (AF_WritingSystem_InitMetricsFunc) af_cjk_metrics_init,        /* style_metrics_init    */
2351     (AF_WritingSystem_ScaleMetricsFunc)af_cjk_metrics_scale,       /* style_metrics_scale   */
2352     (AF_WritingSystem_DoneMetricsFunc) NULL,                       /* style_metrics_done    */
2353     (AF_WritingSystem_GetStdWidthsFunc)af_cjk_get_standard_widths, /* style_metrics_getstdw */
2354 
2355     (AF_WritingSystem_InitHintsFunc)   af_cjk_hints_init,          /* style_hints_init      */
2356     (AF_WritingSystem_ApplyHintsFunc)  af_cjk_hints_apply          /* style_hints_apply     */
2357   )
2358 
2359 
2360 #else /* !AF_CONFIG_OPTION_CJK */
2361 
2362 
2363   AF_DEFINE_WRITING_SYSTEM_CLASS(
2364     af_cjk_writing_system_class,
2365 
2366     AF_WRITING_SYSTEM_CJK,
2367 
2368     sizeof ( AF_CJKMetricsRec ),
2369 
2370     (AF_WritingSystem_InitMetricsFunc) NULL, /* style_metrics_init    */
2371     (AF_WritingSystem_ScaleMetricsFunc)NULL, /* style_metrics_scale   */
2372     (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done    */
2373     (AF_WritingSystem_GetStdWidthsFunc)NULL, /* style_metrics_getstdw */
2374 
2375     (AF_WritingSystem_InitHintsFunc)   NULL, /* style_hints_init      */
2376     (AF_WritingSystem_ApplyHintsFunc)  NULL  /* style_hints_apply     */
2377   )
2378 
2379 
2380 #endif /* !AF_CONFIG_OPTION_CJK */
2381 
2382 
2383 /* END */
2384