1 /****************************************************************************
2  *
3  * afcjk.c
4  *
5  *   Auto-fitter hinting routines for CJK writing system (body).
6  *
7  * Copyright (C) 2006-2020 by
8  * David Turner, Robert Wilhelm, and Werner Lemberg.
9  *
10  * This file is part of the FreeType project, and may only be used,
11  * modified, and distributed under the terms of the FreeType project
12  * license, LICENSE.TXT.  By continuing to use, modify, or distribute
13  * this file you indicate that you have read the license and
14  * understand and accept it fully.
15  *
16  */
17 
18   /*
19    * 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 #ifdef AF_CONFIG_OPTION_USE_WARPER
41 #include "afwarp.h"
42 #endif
43 
44 
45   /**************************************************************************
46    *
47    * The macro FT_COMPONENT is used in trace mode.  It is an implicit
48    * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
49    * messages during execution.
50    */
51 #undef  FT_COMPONENT
52 #define FT_COMPONENT  afcjk
53 
54 
55   /*************************************************************************/
56   /*************************************************************************/
57   /*****                                                               *****/
58   /*****              C J K   G L O B A L   M E T R I C S              *****/
59   /*****                                                               *****/
60   /*************************************************************************/
61   /*************************************************************************/
62 
63 
64   /* Basically the Latin version with AF_CJKMetrics */
65   /* to replace AF_LatinMetrics.                    */
66 
67   FT_LOCAL_DEF( void )
af_cjk_metrics_init_widths(AF_CJKMetrics metrics,FT_Face face)68   af_cjk_metrics_init_widths( AF_CJKMetrics  metrics,
69                               FT_Face        face )
70   {
71     /* scan the array of segments in each direction */
72     AF_GlyphHintsRec  hints[1];
73 
74 
75     FT_TRACE5(( "\n"
76                 "cjk standard widths computation (style `%s')\n"
77                 "===================================================\n"
78                 "\n",
79                 af_style_names[metrics->root.style_class->style] ));
80 
81     af_glyph_hints_init( hints, face->memory );
82 
83     metrics->axis[AF_DIMENSION_HORZ].width_count = 0;
84     metrics->axis[AF_DIMENSION_VERT].width_count = 0;
85 
86     {
87       FT_Error          error;
88       FT_ULong          glyph_index;
89       int               dim;
90       AF_CJKMetricsRec  dummy[1];
91       AF_Scaler         scaler = &dummy->root.scaler;
92 
93       AF_StyleClass   style_class  = metrics->root.style_class;
94       AF_ScriptClass  script_class = af_script_classes[style_class->script];
95 
96       /* If HarfBuzz is not available, we need a pointer to a single */
97       /* unsigned long value.                                        */
98 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
99       void*     shaper_buf;
100 #else
101       FT_ULong  shaper_buf_;
102       void*     shaper_buf = &shaper_buf_;
103 #endif
104 
105       const char*  p;
106 
107 #ifdef FT_DEBUG_LEVEL_TRACE
108       FT_ULong  ch = 0;
109 #endif
110 
111       p = script_class->standard_charstring;
112 
113 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
114       shaper_buf = af_shaper_buf_create( face );
115 #endif
116 
117       /* We check a list of standard characters.  The first match wins. */
118 
119       glyph_index = 0;
120       while ( *p )
121       {
122         unsigned int  num_idx;
123 
124 #ifdef FT_DEBUG_LEVEL_TRACE
125         const char*  p_old;
126 #endif
127 
128 
129         while ( *p == ' ' )
130           p++;
131 
132 #ifdef FT_DEBUG_LEVEL_TRACE
133         p_old = p;
134         GET_UTF8_CHAR( ch, p_old );
135 #endif
136 
137         /* reject input that maps to more than a single glyph */
138         p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
139         if ( num_idx > 1 )
140           continue;
141 
142         /* otherwise exit loop if we have a result */
143         glyph_index = af_shaper_get_elem( &metrics->root,
144                                           shaper_buf,
145                                           0,
146                                           NULL,
147                                           NULL );
148         if ( glyph_index )
149           break;
150       }
151 
152       af_shaper_buf_destroy( face, shaper_buf );
153 
154       if ( !glyph_index )
155         goto Exit;
156 
157       if ( !glyph_index )
158         goto Exit;
159 
160       FT_TRACE5(( "standard character: U+%04lX (glyph index %ld)\n",
161                   ch, glyph_index ));
162 
163       error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
164       if ( error || face->glyph->outline.n_points <= 0 )
165         goto Exit;
166 
167       FT_ZERO( dummy );
168 
169       dummy->units_per_em = metrics->units_per_em;
170 
171       scaler->x_scale = 0x10000L;
172       scaler->y_scale = 0x10000L;
173       scaler->x_delta = 0;
174       scaler->y_delta = 0;
175 
176       scaler->face        = face;
177       scaler->render_mode = FT_RENDER_MODE_NORMAL;
178       scaler->flags       = 0;
179 
180       af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy );
181 
182       error = af_glyph_hints_reload( hints, &face->glyph->outline );
183       if ( error )
184         goto Exit;
185 
186       for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
187       {
188         AF_CJKAxis    axis    = &metrics->axis[dim];
189         AF_AxisHints  axhints = &hints->axis[dim];
190         AF_Segment    seg, limit, link;
191         FT_UInt       num_widths = 0;
192 
193 
194         error = af_latin_hints_compute_segments( hints,
195                                                  (AF_Dimension)dim );
196         if ( error )
197           goto Exit;
198 
199         /*
200          * We assume that the glyphs selected for the stem width
201          * computation are `featureless' enough so that the linking
202          * algorithm works fine without adjustments of its scoring
203          * function.
204          */
205         af_latin_hints_link_segments( hints,
206                                       0,
207                                       NULL,
208                                       (AF_Dimension)dim );
209 
210         seg   = axhints->segments;
211         limit = seg + axhints->num_segments;
212 
213         for ( ; seg < limit; seg++ )
214         {
215           link = seg->link;
216 
217           /* we only consider stem segments there! */
218           if ( link && link->link == seg && link > seg )
219           {
220             FT_Pos  dist;
221 
222 
223             dist = seg->pos - link->pos;
224             if ( dist < 0 )
225               dist = -dist;
226 
227             if ( num_widths < AF_CJK_MAX_WIDTHS )
228               axis->widths[num_widths++].org = dist;
229           }
230         }
231 
232         /* this also replaces multiple almost identical stem widths */
233         /* with a single one (the value 100 is heuristic)           */
234         af_sort_and_quantize_widths( &num_widths, axis->widths,
235                                      dummy->units_per_em / 100 );
236         axis->width_count = num_widths;
237       }
238 
239     Exit:
240       for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
241       {
242         AF_CJKAxis  axis = &metrics->axis[dim];
243         FT_Pos      stdw;
244 
245 
246         stdw = ( axis->width_count > 0 ) ? axis->widths[0].org
247                                          : AF_LATIN_CONSTANT( metrics, 50 );
248 
249         /* let's try 20% of the smallest width */
250         axis->edge_distance_threshold = stdw / 5;
251         axis->standard_width          = stdw;
252         axis->extra_light             = 0;
253 
254 #ifdef FT_DEBUG_LEVEL_TRACE
255         {
256           FT_UInt  i;
257 
258 
259           FT_TRACE5(( "%s widths:\n",
260                       dim == AF_DIMENSION_VERT ? "horizontal"
261                                                : "vertical" ));
262 
263           FT_TRACE5(( "  %ld (standard)", axis->standard_width ));
264           for ( i = 1; i < axis->width_count; i++ )
265             FT_TRACE5(( " %ld", axis->widths[i].org ));
266 
267           FT_TRACE5(( "\n" ));
268         }
269 #endif
270       }
271     }
272 
273     FT_TRACE5(( "\n" ));
274 
275     af_glyph_hints_done( hints );
276   }
277 
278 
279   /* Find all blue zones. */
280 
281   static void
af_cjk_metrics_init_blues(AF_CJKMetrics metrics,FT_Face face)282   af_cjk_metrics_init_blues( AF_CJKMetrics  metrics,
283                              FT_Face        face )
284   {
285     FT_Pos      fills[AF_BLUE_STRING_MAX_LEN];
286     FT_Pos      flats[AF_BLUE_STRING_MAX_LEN];
287 
288     FT_UInt     num_fills;
289     FT_UInt     num_flats;
290 
291     FT_Bool     fill;
292 
293     AF_CJKBlue  blue;
294     FT_Error    error;
295     AF_CJKAxis  axis;
296     FT_Outline  outline;
297 
298     AF_StyleClass  sc = metrics->root.style_class;
299 
300     AF_Blue_Stringset         bss = sc->blue_stringset;
301     const AF_Blue_StringRec*  bs  = &af_blue_stringsets[bss];
302 
303     /* If HarfBuzz is not available, we need a pointer to a single */
304     /* unsigned long value.                                        */
305 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
306     void*     shaper_buf;
307 #else
308     FT_ULong  shaper_buf_;
309     void*     shaper_buf = &shaper_buf_;
310 #endif
311 
312 
313     /* we walk over the blue character strings as specified in the   */
314     /* style's entry in the `af_blue_stringset' array, computing its */
315     /* extremum points (depending on the string properties)          */
316 
317     FT_TRACE5(( "cjk blue zones computation\n"
318                 "==========================\n"
319                 "\n" ));
320 
321 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
322     shaper_buf = af_shaper_buf_create( face );
323 #endif
324 
325     for ( ; bs->string != AF_BLUE_STRING_MAX; bs++ )
326     {
327       const char*  p = &af_blue_strings[bs->string];
328       FT_Pos*      blue_ref;
329       FT_Pos*      blue_shoot;
330 
331 
332       if ( AF_CJK_IS_HORIZ_BLUE( bs ) )
333         axis = &metrics->axis[AF_DIMENSION_HORZ];
334       else
335         axis = &metrics->axis[AF_DIMENSION_VERT];
336 
337 #ifdef FT_DEBUG_LEVEL_TRACE
338       {
339         FT_String*  cjk_blue_name[4] =
340         {
341           (FT_String*)"bottom",    /* --   , --  */
342           (FT_String*)"top",       /* --   , TOP */
343           (FT_String*)"left",      /* HORIZ, --  */
344           (FT_String*)"right"      /* HORIZ, TOP */
345         };
346 
347 
348         FT_TRACE5(( "blue zone %d (%s):\n",
349                     axis->blue_count,
350                     cjk_blue_name[AF_CJK_IS_HORIZ_BLUE( bs ) |
351                                   AF_CJK_IS_TOP_BLUE( bs )   ] ));
352       }
353 #endif /* FT_DEBUG_LEVEL_TRACE */
354 
355       num_fills = 0;
356       num_flats = 0;
357 
358       fill = 1;  /* start with characters that define fill values */
359       FT_TRACE5(( "  [overshoot values]\n" ));
360 
361       while ( *p )
362       {
363         FT_ULong    glyph_index;
364         FT_Pos      best_pos;       /* same as points.y or points.x, resp. */
365         FT_Int      best_point;
366         FT_Vector*  points;
367 
368         unsigned int  num_idx;
369 
370 #ifdef FT_DEBUG_LEVEL_TRACE
371         const char*  p_old;
372         FT_ULong     ch;
373 #endif
374 
375 
376         while ( *p == ' ' )
377           p++;
378 
379 #ifdef FT_DEBUG_LEVEL_TRACE
380         p_old = p;
381         GET_UTF8_CHAR( ch, p_old );
382 #endif
383 
384         /* switch to characters that define flat values */
385         if ( *p == '|' )
386         {
387           fill = 0;
388           FT_TRACE5(( "  [reference values]\n" ));
389           p++;
390           continue;
391         }
392 
393         /* reject input that maps to more than a single glyph */
394         p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
395         if ( num_idx > 1 )
396           continue;
397 
398         /* load the character in the face -- skip unknown or empty ones */
399         glyph_index = af_shaper_get_elem( &metrics->root,
400                                           shaper_buf,
401                                           0,
402                                           NULL,
403                                           NULL );
404         if ( glyph_index == 0 )
405         {
406           FT_TRACE5(( "  U+%04lX unavailable\n", ch ));
407           continue;
408         }
409 
410         error   = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
411         outline = face->glyph->outline;
412         if ( error || outline.n_points <= 2 )
413         {
414           FT_TRACE5(( "  U+%04lX contains no (usable) outlines\n", ch ));
415           continue;
416         }
417 
418         /* now compute min or max point indices and coordinates */
419         points     = outline.points;
420         best_point = -1;
421         best_pos   = 0;  /* make compiler happy */
422 
423         {
424           FT_Int  nn;
425           FT_Int  first = 0;
426           FT_Int  last  = -1;
427 
428 
429           for ( nn = 0; nn < outline.n_contours; first = last + 1, nn++ )
430           {
431             FT_Int  pp;
432 
433 
434             last = outline.contours[nn];
435 
436             /* Avoid single-point contours since they are never rasterized. */
437             /* In some fonts, they correspond to mark attachment points     */
438             /* which are way outside of the glyph's real outline.           */
439             if ( last <= first )
440               continue;
441 
442             if ( AF_CJK_IS_HORIZ_BLUE( bs ) )
443             {
444               if ( AF_CJK_IS_RIGHT_BLUE( bs ) )
445               {
446                 for ( pp = first; pp <= last; pp++ )
447                   if ( best_point < 0 || points[pp].x > best_pos )
448                   {
449                     best_point = pp;
450                     best_pos   = points[pp].x;
451                   }
452               }
453               else
454               {
455                 for ( pp = first; pp <= last; pp++ )
456                   if ( best_point < 0 || points[pp].x < best_pos )
457                   {
458                     best_point = pp;
459                     best_pos   = points[pp].x;
460                   }
461               }
462             }
463             else
464             {
465               if ( AF_CJK_IS_TOP_BLUE( bs ) )
466               {
467                 for ( pp = first; pp <= last; pp++ )
468                   if ( best_point < 0 || points[pp].y > best_pos )
469                   {
470                     best_point = pp;
471                     best_pos   = points[pp].y;
472                   }
473               }
474               else
475               {
476                 for ( pp = first; pp <= last; pp++ )
477                   if ( best_point < 0 || points[pp].y < best_pos )
478                   {
479                     best_point = pp;
480                     best_pos   = points[pp].y;
481                   }
482               }
483             }
484           }
485 
486           FT_TRACE5(( "  U+%04lX: best_pos = %5ld\n", ch, best_pos ));
487         }
488 
489         if ( fill )
490           fills[num_fills++] = best_pos;
491         else
492           flats[num_flats++] = best_pos;
493 
494       } /* end while loop */
495 
496       if ( num_flats == 0 && num_fills == 0 )
497       {
498         /*
499          * we couldn't find a single glyph to compute this blue zone,
500          * we will simply ignore it then
501          */
502         FT_TRACE5(( "  empty\n" ));
503         continue;
504       }
505 
506       /* we have computed the contents of the `fill' and `flats' tables,   */
507       /* now determine the reference and overshoot position of the blue -- */
508       /* we simply take the median value after a simple sort               */
509       af_sort_pos( num_fills, fills );
510       af_sort_pos( num_flats, flats );
511 
512       blue       = &axis->blues[axis->blue_count];
513       blue_ref   = &blue->ref.org;
514       blue_shoot = &blue->shoot.org;
515 
516       axis->blue_count++;
517 
518       if ( num_flats == 0 )
519       {
520         *blue_ref   =
521         *blue_shoot = fills[num_fills / 2];
522       }
523       else if ( num_fills == 0 )
524       {
525         *blue_ref   =
526         *blue_shoot = flats[num_flats / 2];
527       }
528       else
529       {
530         *blue_ref   = fills[num_fills / 2];
531         *blue_shoot = flats[num_flats / 2];
532       }
533 
534       /* make sure blue_ref >= blue_shoot for top/right or */
535       /* vice versa for bottom/left                        */
536       if ( *blue_shoot != *blue_ref )
537       {
538         FT_Pos   ref       = *blue_ref;
539         FT_Pos   shoot     = *blue_shoot;
540         FT_Bool  under_ref = FT_BOOL( shoot < ref );
541 
542 
543         /* AF_CJK_IS_TOP_BLUE covers `right' and `top' */
544         if ( AF_CJK_IS_TOP_BLUE( bs ) ^ under_ref )
545         {
546           *blue_ref   =
547           *blue_shoot = ( shoot + ref ) / 2;
548 
549           FT_TRACE5(( "  [reference smaller than overshoot,"
550                       " taking mean value]\n" ));
551         }
552       }
553 
554       blue->flags = 0;
555       if ( AF_CJK_IS_TOP_BLUE( bs ) )
556         blue->flags |= AF_CJK_BLUE_TOP;
557 
558       FT_TRACE5(( "    -> reference = %ld\n"
559                   "       overshoot = %ld\n",
560                   *blue_ref, *blue_shoot ));
561 
562     } /* end for loop */
563 
564     af_shaper_buf_destroy( face, shaper_buf );
565 
566     FT_TRACE5(( "\n" ));
567 
568     return;
569   }
570 
571 
572   /* Basically the Latin version with type AF_CJKMetrics for metrics. */
573 
574   FT_LOCAL_DEF( void )
af_cjk_metrics_check_digits(AF_CJKMetrics metrics,FT_Face face)575   af_cjk_metrics_check_digits( AF_CJKMetrics  metrics,
576                                FT_Face        face )
577   {
578     FT_Bool   started = 0, same_width = 1;
579     FT_Fixed  advance = 0, old_advance = 0;
580 
581     /* If HarfBuzz is not available, we need a pointer to a single */
582     /* unsigned long value.                                        */
583 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
584     void*     shaper_buf;
585 #else
586     FT_ULong  shaper_buf_;
587     void*     shaper_buf = &shaper_buf_;
588 #endif
589 
590     /* in all supported charmaps, digits have character codes 0x30-0x39 */
591     const char   digits[] = "0 1 2 3 4 5 6 7 8 9";
592     const char*  p;
593 
594 
595     p = digits;
596 
597 #ifdef FT_CONFIG_OPTION_USE_HARFBUZZ
598     shaper_buf = af_shaper_buf_create( face );
599 #endif
600 
601     while ( *p )
602     {
603       FT_ULong      glyph_index;
604       unsigned int  num_idx;
605 
606 
607       /* reject input that maps to more than a single glyph */
608       p = af_shaper_get_cluster( p, &metrics->root, shaper_buf, &num_idx );
609       if ( num_idx > 1 )
610         continue;
611 
612       glyph_index = af_shaper_get_elem( &metrics->root,
613                                         shaper_buf,
614                                         0,
615                                         &advance,
616                                         NULL );
617       if ( !glyph_index )
618         continue;
619 
620       if ( started )
621       {
622         if ( advance != old_advance )
623         {
624           same_width = 0;
625           break;
626         }
627       }
628       else
629       {
630         old_advance = advance;
631         started     = 1;
632       }
633     }
634 
635     af_shaper_buf_destroy( face, shaper_buf );
636 
637     metrics->root.digits_have_same_width = same_width;
638   }
639 
640 
641   /* Initialize global metrics. */
642 
643   FT_LOCAL_DEF( FT_Error )
af_cjk_metrics_init(AF_CJKMetrics metrics,FT_Face face)644   af_cjk_metrics_init( AF_CJKMetrics  metrics,
645                        FT_Face        face )
646   {
647     FT_CharMap  oldmap = face->charmap;
648 
649 
650     metrics->units_per_em = face->units_per_EM;
651 
652     if ( !FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
653     {
654       af_cjk_metrics_init_widths( metrics, face );
655       af_cjk_metrics_init_blues( metrics, face );
656       af_cjk_metrics_check_digits( metrics, face );
657     }
658 
659     FT_Set_Charmap( face, oldmap );
660     return FT_Err_Ok;
661   }
662 
663 
664   /* Adjust scaling value, then scale and shift widths   */
665   /* and blue zones (if applicable) for given dimension. */
666 
667   static void
af_cjk_metrics_scale_dim(AF_CJKMetrics metrics,AF_Scaler scaler,AF_Dimension dim)668   af_cjk_metrics_scale_dim( AF_CJKMetrics  metrics,
669                             AF_Scaler      scaler,
670                             AF_Dimension   dim )
671   {
672     FT_Fixed    scale;
673     FT_Pos      delta;
674     AF_CJKAxis  axis;
675     FT_UInt     nn;
676 
677 
678     if ( dim == AF_DIMENSION_HORZ )
679     {
680       scale = scaler->x_scale;
681       delta = scaler->x_delta;
682     }
683     else
684     {
685       scale = scaler->y_scale;
686       delta = scaler->y_delta;
687     }
688 
689     axis = &metrics->axis[dim];
690 
691     if ( axis->org_scale == scale && axis->org_delta == delta )
692       return;
693 
694     axis->org_scale = scale;
695     axis->org_delta = delta;
696 
697     axis->scale = scale;
698     axis->delta = delta;
699 
700     /* scale the blue zones */
701     for ( nn = 0; nn < axis->blue_count; nn++ )
702     {
703       AF_CJKBlue  blue = &axis->blues[nn];
704       FT_Pos      dist;
705 
706 
707       blue->ref.cur   = FT_MulFix( blue->ref.org, scale ) + delta;
708       blue->ref.fit   = blue->ref.cur;
709       blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
710       blue->shoot.fit = blue->shoot.cur;
711       blue->flags    &= ~AF_CJK_BLUE_ACTIVE;
712 
713       /* a blue zone is only active if it is less than 3/4 pixels tall */
714       dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
715       if ( dist <= 48 && dist >= -48 )
716       {
717         FT_Pos  delta1, delta2;
718 
719 
720         blue->ref.fit  = FT_PIX_ROUND( blue->ref.cur );
721 
722         /* shoot is under shoot for cjk */
723         delta1 = FT_DivFix( blue->ref.fit, scale ) - blue->shoot.org;
724         delta2 = delta1;
725         if ( delta1 < 0 )
726           delta2 = -delta2;
727 
728         delta2 = FT_MulFix( delta2, scale );
729 
730         FT_TRACE5(( "delta: %ld", delta1 ));
731         if ( delta2 < 32 )
732           delta2 = 0;
733 #if 0
734         else if ( delta2 < 64 )
735           delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
736 #endif
737         else
738           delta2 = FT_PIX_ROUND( delta2 );
739         FT_TRACE5(( "/%ld\n", delta2 ));
740 
741         if ( delta1 < 0 )
742           delta2 = -delta2;
743 
744         blue->shoot.fit = blue->ref.fit - delta2;
745 
746         FT_TRACE5(( ">> active cjk blue zone %c%d[%ld/%ld]:\n"
747                     "     ref:   cur=%.2f fit=%.2f\n"
748                     "     shoot: cur=%.2f fit=%.2f\n",
749                     ( dim == AF_DIMENSION_HORZ ) ? 'H' : 'V',
750                     nn, blue->ref.org, blue->shoot.org,
751                     blue->ref.cur / 64.0, blue->ref.fit / 64.0,
752                     blue->shoot.cur / 64.0, blue->shoot.fit / 64.0 ));
753 
754         blue->flags |= AF_CJK_BLUE_ACTIVE;
755       }
756     }
757   }
758 
759 
760   /* Scale global values in both directions. */
761 
762   FT_LOCAL_DEF( void )
af_cjk_metrics_scale(AF_CJKMetrics metrics,AF_Scaler scaler)763   af_cjk_metrics_scale( AF_CJKMetrics  metrics,
764                         AF_Scaler      scaler )
765   {
766     /* we copy the whole structure since the x and y scaling values */
767     /* are not modified, contrary to e.g. the `latin' auto-hinter   */
768     metrics->root.scaler = *scaler;
769 
770     af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
771     af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
772   }
773 
774 
775   /* Extract standard_width from writing system/script specific */
776   /* metrics class.                                             */
777 
778   FT_LOCAL_DEF( void )
af_cjk_get_standard_widths(AF_CJKMetrics metrics,FT_Pos * stdHW,FT_Pos * stdVW)779   af_cjk_get_standard_widths( AF_CJKMetrics  metrics,
780                               FT_Pos*        stdHW,
781                               FT_Pos*        stdVW )
782   {
783     if ( stdHW )
784       *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width;
785 
786     if ( stdVW )
787       *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width;
788   }
789 
790 
791   /*************************************************************************/
792   /*************************************************************************/
793   /*****                                                               *****/
794   /*****              C J K   G L Y P H   A N A L Y S I S              *****/
795   /*****                                                               *****/
796   /*************************************************************************/
797   /*************************************************************************/
798 
799 
800   /* Walk over all contours and compute its segments. */
801 
802   static FT_Error
af_cjk_hints_compute_segments(AF_GlyphHints hints,AF_Dimension dim)803   af_cjk_hints_compute_segments( AF_GlyphHints  hints,
804                                  AF_Dimension   dim )
805   {
806     AF_AxisHints  axis          = &hints->axis[dim];
807     AF_Segment    segments      = axis->segments;
808     AF_Segment    segment_limit = FT_OFFSET( segments, axis->num_segments );
809     FT_Error      error;
810     AF_Segment    seg;
811 
812 
813     error = af_latin_hints_compute_segments( hints, dim );
814     if ( error )
815       return error;
816 
817     /* a segment is round if it doesn't have successive */
818     /* on-curve points.                                 */
819     for ( seg = segments; seg < segment_limit; seg++ )
820     {
821       AF_Point  pt   = seg->first;
822       AF_Point  last = seg->last;
823       FT_UInt   f0   = pt->flags & AF_FLAG_CONTROL;
824       FT_UInt   f1;
825 
826 
827       seg->flags &= ~AF_EDGE_ROUND;
828 
829       for ( ; pt != last; f0 = f1 )
830       {
831         pt = pt->next;
832         f1 = pt->flags & AF_FLAG_CONTROL;
833 
834         if ( !f0 && !f1 )
835           break;
836 
837         if ( pt == last )
838           seg->flags |= AF_EDGE_ROUND;
839       }
840     }
841 
842     return FT_Err_Ok;
843   }
844 
845 
846   static void
af_cjk_hints_link_segments(AF_GlyphHints hints,AF_Dimension dim)847   af_cjk_hints_link_segments( AF_GlyphHints  hints,
848                               AF_Dimension   dim )
849   {
850     AF_AxisHints  axis          = &hints->axis[dim];
851     AF_Segment    segments      = axis->segments;
852     AF_Segment    segment_limit = segments + axis->num_segments;
853     AF_Direction  major_dir     = axis->major_dir;
854     AF_Segment    seg1, seg2;
855     FT_Pos        len_threshold;
856     FT_Pos        dist_threshold;
857 
858 
859     len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
860 
861     dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
862                                                   : hints->y_scale;
863     dist_threshold = FT_DivFix( 64 * 3, dist_threshold );
864 
865     /* now compare each segment to the others */
866     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
867     {
868       if ( seg1->dir != major_dir )
869         continue;
870 
871       for ( seg2 = segments; seg2 < segment_limit; seg2++ )
872         if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
873         {
874           FT_Pos  dist = seg2->pos - seg1->pos;
875 
876 
877           if ( dist < 0 )
878             continue;
879 
880           {
881             FT_Pos  min = seg1->min_coord;
882             FT_Pos  max = seg1->max_coord;
883             FT_Pos  len;
884 
885 
886             if ( min < seg2->min_coord )
887               min = seg2->min_coord;
888 
889             if ( max > seg2->max_coord )
890               max = seg2->max_coord;
891 
892             len = max - min;
893             if ( len >= len_threshold )
894             {
895               if ( dist * 8 < seg1->score * 9                        &&
896                    ( dist * 8 < seg1->score * 7 || seg1->len < len ) )
897               {
898                 seg1->score = dist;
899                 seg1->len   = len;
900                 seg1->link  = seg2;
901               }
902 
903               if ( dist * 8 < seg2->score * 9                        &&
904                    ( dist * 8 < seg2->score * 7 || seg2->len < len ) )
905               {
906                 seg2->score = dist;
907                 seg2->len   = len;
908                 seg2->link  = seg1;
909               }
910             }
911           }
912         }
913     }
914 
915     /*
916      * now compute the `serif' segments
917      *
918      * In Hanzi, some strokes are wider on one or both of the ends.
919      * We either identify the stems on the ends as serifs or remove
920      * the linkage, depending on the length of the stems.
921      *
922      */
923 
924     {
925       AF_Segment  link1, link2;
926 
927 
928       for ( seg1 = segments; seg1 < segment_limit; seg1++ )
929       {
930         link1 = seg1->link;
931         if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos )
932           continue;
933 
934         if ( seg1->score >= dist_threshold )
935           continue;
936 
937         for ( seg2 = segments; seg2 < segment_limit; seg2++ )
938         {
939           if ( seg2->pos > seg1->pos || seg1 == seg2 )
940             continue;
941 
942           link2 = seg2->link;
943           if ( !link2 || link2->link != seg2 || link2->pos < link1->pos )
944             continue;
945 
946           if ( seg1->pos == seg2->pos && link1->pos == link2->pos )
947             continue;
948 
949           if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score )
950             continue;
951 
952           /* seg2 < seg1 < link1 < link2 */
953 
954           if ( seg1->len >= seg2->len * 3 )
955           {
956             AF_Segment  seg;
957 
958 
959             for ( seg = segments; seg < segment_limit; seg++ )
960             {
961               AF_Segment  link = seg->link;
962 
963 
964               if ( link == seg2 )
965               {
966                 seg->link  = NULL;
967                 seg->serif = link1;
968               }
969               else if ( link == link2 )
970               {
971                 seg->link  = NULL;
972                 seg->serif = seg1;
973               }
974             }
975           }
976           else
977           {
978             seg1->link = link1->link = NULL;
979 
980             break;
981           }
982         }
983       }
984     }
985 
986     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
987     {
988       seg2 = seg1->link;
989 
990       if ( seg2 )
991       {
992         if ( seg2->link != seg1 )
993         {
994           seg1->link = NULL;
995 
996           if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 )
997             seg1->serif = seg2->link;
998         }
999       }
1000     }
1001   }
1002 
1003 
1004   static FT_Error
af_cjk_hints_compute_edges(AF_GlyphHints hints,AF_Dimension dim)1005   af_cjk_hints_compute_edges( AF_GlyphHints  hints,
1006                               AF_Dimension   dim )
1007   {
1008     AF_AxisHints  axis   = &hints->axis[dim];
1009     FT_Error      error  = FT_Err_Ok;
1010     FT_Memory     memory = hints->memory;
1011     AF_CJKAxis    laxis  = &((AF_CJKMetrics)hints->metrics)->axis[dim];
1012 
1013     AF_Segment    segments      = axis->segments;
1014     AF_Segment    segment_limit = segments + axis->num_segments;
1015     AF_Segment    seg;
1016 
1017     FT_Fixed      scale;
1018     FT_Pos        edge_distance_threshold;
1019 
1020 
1021     axis->num_edges = 0;
1022 
1023     scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
1024                                          : hints->y_scale;
1025 
1026     /**********************************************************************
1027      *
1028      * We begin by generating a sorted table of edges for the current
1029      * direction.  To do so, we simply scan each segment and try to find
1030      * an edge in our table that corresponds to its position.
1031      *
1032      * If no edge is found, we create and insert a new edge in the
1033      * sorted table.  Otherwise, we simply add the segment to the edge's
1034      * list which is then processed in the second step to compute the
1035      * edge's properties.
1036      *
1037      * Note that the edges table is sorted along the segment/edge
1038      * position.
1039      *
1040      */
1041 
1042     edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
1043                                          scale );
1044     if ( edge_distance_threshold > 64 / 4 )
1045       edge_distance_threshold = FT_DivFix( 64 / 4, scale );
1046     else
1047       edge_distance_threshold = laxis->edge_distance_threshold;
1048 
1049     for ( seg = segments; seg < segment_limit; seg++ )
1050     {
1051       AF_Edge  found = NULL;
1052       FT_Pos   best  = 0xFFFFU;
1053       FT_Int   ee;
1054 
1055 
1056       /* look for an edge corresponding to the segment */
1057       for ( ee = 0; ee < axis->num_edges; ee++ )
1058       {
1059         AF_Edge  edge = axis->edges + ee;
1060         FT_Pos   dist;
1061 
1062 
1063         if ( edge->dir != seg->dir )
1064           continue;
1065 
1066         dist = seg->pos - edge->fpos;
1067         if ( dist < 0 )
1068           dist = -dist;
1069 
1070         if ( dist < edge_distance_threshold && dist < best )
1071         {
1072           AF_Segment  link = seg->link;
1073 
1074 
1075           /* check whether all linked segments of the candidate edge */
1076           /* can make a single edge.                                 */
1077           if ( link )
1078           {
1079             AF_Segment  seg1  = edge->first;
1080             FT_Pos      dist2 = 0;
1081 
1082 
1083             do
1084             {
1085               AF_Segment  link1 = seg1->link;
1086 
1087 
1088               if ( link1 )
1089               {
1090                 dist2 = AF_SEGMENT_DIST( link, link1 );
1091                 if ( dist2 >= edge_distance_threshold )
1092                   break;
1093               }
1094 
1095             } while ( ( seg1 = seg1->edge_next ) != edge->first );
1096 
1097             if ( dist2 >= edge_distance_threshold )
1098               continue;
1099           }
1100 
1101           best  = dist;
1102           found = edge;
1103         }
1104       }
1105 
1106       if ( !found )
1107       {
1108         AF_Edge  edge;
1109 
1110 
1111         /* insert a new edge in the list and */
1112         /* sort according to the position    */
1113         error = af_axis_hints_new_edge( axis, seg->pos,
1114                                         (AF_Direction)seg->dir, 0,
1115                                         memory, &edge );
1116         if ( error )
1117           goto Exit;
1118 
1119         /* add the segment to the new edge's list */
1120         FT_ZERO( edge );
1121 
1122         edge->first    = seg;
1123         edge->last     = seg;
1124         edge->dir      = seg->dir;
1125         edge->fpos     = seg->pos;
1126         edge->opos     = FT_MulFix( seg->pos, scale );
1127         edge->pos      = edge->opos;
1128         seg->edge_next = seg;
1129       }
1130       else
1131       {
1132         /* if an edge was found, simply add the segment to the edge's */
1133         /* list                                                       */
1134         seg->edge_next         = found->first;
1135         found->last->edge_next = seg;
1136         found->last            = seg;
1137       }
1138     }
1139 
1140     /*******************************************************************
1141      *
1142      * Good, we now compute each edge's properties according to the
1143      * segments found on its position.  Basically, these are
1144      *
1145      * - the edge's main direction
1146      * - stem edge, serif edge or both (which defaults to stem then)
1147      * - rounded edge, straight or both (which defaults to straight)
1148      * - link for edge
1149      *
1150      */
1151 
1152     /* first of all, set the `edge' field in each segment -- this is */
1153     /* required in order to compute edge links                       */
1154 
1155     /*
1156      * Note that removing this loop and setting the `edge' field of each
1157      * segment directly in the code above slows down execution speed for
1158      * some reasons on platforms like the Sun.
1159      */
1160     {
1161       AF_Edge  edges      = axis->edges;
1162       AF_Edge  edge_limit = edges + axis->num_edges;
1163       AF_Edge  edge;
1164 
1165 
1166       for ( edge = edges; edge < edge_limit; edge++ )
1167       {
1168         seg = edge->first;
1169         if ( seg )
1170           do
1171           {
1172             seg->edge = edge;
1173             seg       = seg->edge_next;
1174 
1175           } while ( seg != edge->first );
1176       }
1177 
1178       /* now compute each edge properties */
1179       for ( edge = edges; edge < edge_limit; edge++ )
1180       {
1181         FT_Int  is_round    = 0;  /* does it contain round segments?    */
1182         FT_Int  is_straight = 0;  /* does it contain straight segments? */
1183 
1184 
1185         seg = edge->first;
1186         if ( !seg )
1187           goto Skip_Loop;
1188 
1189         do
1190         {
1191           FT_Bool  is_serif;
1192 
1193 
1194           /* check for roundness of segment */
1195           if ( seg->flags & AF_EDGE_ROUND )
1196             is_round++;
1197           else
1198             is_straight++;
1199 
1200           /* check for links -- if seg->serif is set, then seg->link must */
1201           /* be ignored                                                   */
1202           is_serif = FT_BOOL( seg->serif && seg->serif->edge != edge );
1203 
1204           if ( seg->link || is_serif )
1205           {
1206             AF_Edge     edge2;
1207             AF_Segment  seg2;
1208 
1209 
1210             edge2 = edge->link;
1211             seg2  = seg->link;
1212 
1213             if ( is_serif )
1214             {
1215               seg2  = seg->serif;
1216               edge2 = edge->serif;
1217             }
1218 
1219             if ( edge2 )
1220             {
1221               FT_Pos  edge_delta;
1222               FT_Pos  seg_delta;
1223 
1224 
1225               edge_delta = edge->fpos - edge2->fpos;
1226               if ( edge_delta < 0 )
1227                 edge_delta = -edge_delta;
1228 
1229               seg_delta = AF_SEGMENT_DIST( seg, seg2 );
1230 
1231               if ( seg_delta < edge_delta )
1232                 edge2 = seg2->edge;
1233             }
1234             else
1235               edge2 = seg2->edge;
1236 
1237             if ( is_serif )
1238             {
1239               edge->serif   = edge2;
1240               edge2->flags |= AF_EDGE_SERIF;
1241             }
1242             else
1243               edge->link = edge2;
1244           }
1245 
1246           seg = seg->edge_next;
1247 
1248         } while ( seg != edge->first );
1249 
1250       Skip_Loop:
1251         /* set the round/straight flags */
1252         edge->flags = AF_EDGE_NORMAL;
1253 
1254         if ( is_round > 0 && is_round >= is_straight )
1255           edge->flags |= AF_EDGE_ROUND;
1256 
1257         /* get rid of serifs if link is set                 */
1258         /* XXX: This gets rid of many unpleasant artefacts! */
1259         /*      Example: the `c' in cour.pfa at size 13     */
1260 
1261         if ( edge->serif && edge->link )
1262           edge->serif = NULL;
1263       }
1264     }
1265 
1266   Exit:
1267     return error;
1268   }
1269 
1270 
1271   /* Detect segments and edges for given dimension. */
1272 
1273   static FT_Error
af_cjk_hints_detect_features(AF_GlyphHints hints,AF_Dimension dim)1274   af_cjk_hints_detect_features( AF_GlyphHints  hints,
1275                                 AF_Dimension   dim )
1276   {
1277     FT_Error  error;
1278 
1279 
1280     error = af_cjk_hints_compute_segments( hints, dim );
1281     if ( !error )
1282     {
1283       af_cjk_hints_link_segments( hints, dim );
1284 
1285       error = af_cjk_hints_compute_edges( hints, dim );
1286     }
1287     return error;
1288   }
1289 
1290 
1291   /* Compute all edges which lie within blue zones. */
1292 
1293   static void
af_cjk_hints_compute_blue_edges(AF_GlyphHints hints,AF_CJKMetrics metrics,AF_Dimension dim)1294   af_cjk_hints_compute_blue_edges( AF_GlyphHints  hints,
1295                                    AF_CJKMetrics  metrics,
1296                                    AF_Dimension   dim )
1297   {
1298     AF_AxisHints  axis       = &hints->axis[dim];
1299     AF_Edge       edge       = axis->edges;
1300     AF_Edge       edge_limit = edge + axis->num_edges;
1301     AF_CJKAxis    cjk        = &metrics->axis[dim];
1302     FT_Fixed      scale      = cjk->scale;
1303     FT_Pos        best_dist0;  /* initial threshold */
1304 
1305 
1306     /* compute the initial threshold as a fraction of the EM size */
1307     best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
1308 
1309     if ( best_dist0 > 64 / 2 ) /* maximum 1/2 pixel */
1310       best_dist0 = 64 / 2;
1311 
1312     /* compute which blue zones are active, i.e. have their scaled */
1313     /* size < 3/4 pixels                                           */
1314 
1315     /* If the distant between an edge and a blue zone is shorter than */
1316     /* best_dist0, set the blue zone for the edge.  Then search for   */
1317     /* the blue zone with the smallest best_dist to the edge.         */
1318 
1319     for ( ; edge < edge_limit; edge++ )
1320     {
1321       FT_UInt   bb;
1322       AF_Width  best_blue = NULL;
1323       FT_Pos    best_dist = best_dist0;
1324 
1325 
1326       for ( bb = 0; bb < cjk->blue_count; bb++ )
1327       {
1328         AF_CJKBlue  blue = cjk->blues + bb;
1329         FT_Bool     is_top_right_blue, is_major_dir;
1330 
1331 
1332         /* skip inactive blue zones (i.e., those that are too small) */
1333         if ( !( blue->flags & AF_CJK_BLUE_ACTIVE ) )
1334           continue;
1335 
1336         /* if it is a top zone, check for right edges -- if it is a bottom */
1337         /* zone, check for left edges                                      */
1338         /*                                                                 */
1339         /* of course, that's for TrueType                                  */
1340         is_top_right_blue =
1341           (FT_Byte)( ( blue->flags & AF_CJK_BLUE_TOP ) != 0 );
1342         is_major_dir =
1343           FT_BOOL( edge->dir == axis->major_dir );
1344 
1345         /* if it is a top zone, the edge must be against the major    */
1346         /* direction; if it is a bottom zone, it must be in the major */
1347         /* direction                                                  */
1348         if ( is_top_right_blue ^ is_major_dir )
1349         {
1350           FT_Pos    dist;
1351           AF_Width  compare;
1352 
1353 
1354           /* Compare the edge to the closest blue zone type */
1355           if ( FT_ABS( edge->fpos - blue->ref.org ) >
1356                FT_ABS( edge->fpos - blue->shoot.org ) )
1357             compare = &blue->shoot;
1358           else
1359             compare = &blue->ref;
1360 
1361           dist = edge->fpos - compare->org;
1362           if ( dist < 0 )
1363             dist = -dist;
1364 
1365           dist = FT_MulFix( dist, scale );
1366           if ( dist < best_dist )
1367           {
1368             best_dist = dist;
1369             best_blue = compare;
1370           }
1371         }
1372       }
1373 
1374       if ( best_blue )
1375         edge->blue_edge = best_blue;
1376     }
1377   }
1378 
1379 
1380   /* Initalize hinting engine. */
1381 
1382   FT_LOCAL_DEF( FT_Error )
af_cjk_hints_init(AF_GlyphHints hints,AF_CJKMetrics metrics)1383   af_cjk_hints_init( AF_GlyphHints  hints,
1384                      AF_CJKMetrics  metrics )
1385   {
1386     FT_Render_Mode  mode;
1387     FT_UInt32       scaler_flags, other_flags;
1388 
1389 
1390     af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics );
1391 
1392     /*
1393      * correct x_scale and y_scale when needed, since they may have
1394      * been modified af_cjk_scale_dim above
1395      */
1396     hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
1397     hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
1398     hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
1399     hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
1400 
1401     /* compute flags depending on render mode, etc. */
1402     mode = metrics->root.scaler.render_mode;
1403 
1404 #if 0 /* AF_CONFIG_OPTION_USE_WARPER */
1405     if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
1406       metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
1407 #endif
1408 
1409     scaler_flags = hints->scaler_flags;
1410     other_flags  = 0;
1411 
1412     /*
1413      * We snap the width of vertical stems for the monochrome and
1414      * horizontal LCD rendering targets only.
1415      */
1416     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
1417       other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
1418 
1419     /*
1420      * We snap the width of horizontal stems for the monochrome and
1421      * vertical LCD rendering targets only.
1422      */
1423     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
1424       other_flags |= AF_LATIN_HINTS_VERT_SNAP;
1425 
1426     /*
1427      * We adjust stems to full pixels unless in `light' or `lcd' mode.
1428      */
1429     if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD )
1430       other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
1431 
1432     if ( mode == FT_RENDER_MODE_MONO )
1433       other_flags |= AF_LATIN_HINTS_MONO;
1434 
1435     scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE;
1436 
1437 #ifdef AF_CONFIG_OPTION_USE_WARPER
1438     /* get (global) warper flag */
1439     if ( !metrics->root.globals->module->warping )
1440       scaler_flags |= AF_SCALER_FLAG_NO_WARPER;
1441 #endif
1442 
1443     hints->scaler_flags = scaler_flags;
1444     hints->other_flags  = other_flags;
1445 
1446     return FT_Err_Ok;
1447   }
1448 
1449 
1450   /*************************************************************************/
1451   /*************************************************************************/
1452   /*****                                                               *****/
1453   /*****          C J K   G L Y P H   G R I D - F I T T I N G          *****/
1454   /*****                                                               *****/
1455   /*************************************************************************/
1456   /*************************************************************************/
1457 
1458   /* Snap a given width in scaled coordinates to one of the */
1459   /* current standard widths.                               */
1460 
1461   static FT_Pos
af_cjk_snap_width(AF_Width widths,FT_UInt count,FT_Pos width)1462   af_cjk_snap_width( AF_Width  widths,
1463                      FT_UInt   count,
1464                      FT_Pos    width )
1465   {
1466     FT_UInt  n;
1467     FT_Pos   best      = 64 + 32 + 2;
1468     FT_Pos   reference = width;
1469     FT_Pos   scaled;
1470 
1471 
1472     for ( n = 0; n < count; n++ )
1473     {
1474       FT_Pos  w;
1475       FT_Pos  dist;
1476 
1477 
1478       w = widths[n].cur;
1479       dist = width - w;
1480       if ( dist < 0 )
1481         dist = -dist;
1482       if ( dist < best )
1483       {
1484         best      = dist;
1485         reference = w;
1486       }
1487     }
1488 
1489     scaled = FT_PIX_ROUND( reference );
1490 
1491     if ( width >= reference )
1492     {
1493       if ( width < scaled + 48 )
1494         width = reference;
1495     }
1496     else
1497     {
1498       if ( width > scaled - 48 )
1499         width = reference;
1500     }
1501 
1502     return width;
1503   }
1504 
1505 
1506   /* Compute the snapped width of a given stem.                          */
1507   /* There is a lot of voodoo in this function; changing the hard-coded  */
1508   /* parameters influence the whole hinting process.                     */
1509 
1510   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)1511   af_cjk_compute_stem_width( AF_GlyphHints  hints,
1512                              AF_Dimension   dim,
1513                              FT_Pos         width,
1514                              FT_UInt        base_flags,
1515                              FT_UInt        stem_flags )
1516   {
1517     AF_CJKMetrics  metrics  = (AF_CJKMetrics)hints->metrics;
1518     AF_CJKAxis     axis     = &metrics->axis[dim];
1519     FT_Pos         dist     = width;
1520     FT_Int         sign     = 0;
1521     FT_Bool        vertical = FT_BOOL( dim == AF_DIMENSION_VERT );
1522 
1523     FT_UNUSED( base_flags );
1524     FT_UNUSED( stem_flags );
1525 
1526 
1527     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1528       return width;
1529 
1530     if ( dist < 0 )
1531     {
1532       dist = -width;
1533       sign = 1;
1534     }
1535 
1536     if ( (  vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
1537          ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
1538     {
1539       /* smooth hinting process: very lightly quantize the stem width */
1540 
1541       if ( axis->width_count > 0 )
1542       {
1543         if ( FT_ABS( dist - axis->widths[0].cur ) < 40 )
1544         {
1545           dist = axis->widths[0].cur;
1546           if ( dist < 48 )
1547             dist = 48;
1548 
1549           goto Done_Width;
1550         }
1551       }
1552 
1553       if ( dist < 54 )
1554         dist += ( 54 - dist ) / 2;
1555       else if ( dist < 3 * 64 )
1556       {
1557         FT_Pos  delta;
1558 
1559 
1560         delta  = dist & 63;
1561         dist  &= -64;
1562 
1563         if ( delta < 10 )
1564           dist += delta;
1565         else if ( delta < 22 )
1566           dist += 10;
1567         else if ( delta < 42 )
1568           dist += delta;
1569         else if ( delta < 54 )
1570           dist += 54;
1571         else
1572           dist += delta;
1573       }
1574     }
1575     else
1576     {
1577       /* strong hinting process: snap the stem width to integer pixels */
1578 
1579       dist = af_cjk_snap_width( axis->widths, axis->width_count, dist );
1580 
1581       if ( vertical )
1582       {
1583         /* in the case of vertical hinting, always round */
1584         /* the stem heights to integer pixels            */
1585 
1586         if ( dist >= 64 )
1587           dist = ( dist + 16 ) & ~63;
1588         else
1589           dist = 64;
1590       }
1591       else
1592       {
1593         if ( AF_LATIN_HINTS_DO_MONO( hints ) )
1594         {
1595           /* monochrome horizontal hinting: snap widths to integer pixels */
1596           /* with a different threshold                                   */
1597 
1598           if ( dist < 64 )
1599             dist = 64;
1600           else
1601             dist = ( dist + 32 ) & ~63;
1602         }
1603         else
1604         {
1605           /* for horizontal anti-aliased hinting, we adopt a more subtle */
1606           /* approach: we strengthen small stems, round stems whose size */
1607           /* is between 1 and 2 pixels to an integer, otherwise nothing  */
1608 
1609           if ( dist < 48 )
1610             dist = ( dist + 64 ) >> 1;
1611 
1612           else if ( dist < 128 )
1613             dist = ( dist + 22 ) & ~63;
1614           else
1615             /* round otherwise to prevent color fringes in LCD mode */
1616             dist = ( dist + 32 ) & ~63;
1617         }
1618       }
1619     }
1620 
1621   Done_Width:
1622     if ( sign )
1623       dist = -dist;
1624 
1625     return dist;
1626   }
1627 
1628 
1629   /* Align one stem edge relative to the previous stem edge. */
1630 
1631   static void
af_cjk_align_linked_edge(AF_GlyphHints hints,AF_Dimension dim,AF_Edge base_edge,AF_Edge stem_edge)1632   af_cjk_align_linked_edge( AF_GlyphHints  hints,
1633                             AF_Dimension   dim,
1634                             AF_Edge        base_edge,
1635                             AF_Edge        stem_edge )
1636   {
1637     FT_Pos  dist = stem_edge->opos - base_edge->opos;
1638 
1639     FT_Pos  fitted_width = af_cjk_compute_stem_width( hints, dim, dist,
1640                                                       base_edge->flags,
1641                                                       stem_edge->flags );
1642 
1643 
1644     stem_edge->pos = base_edge->pos + fitted_width;
1645 
1646     FT_TRACE5(( "  CJKLINK: edge %ld @%d (opos=%.2f) linked to %.2f,"
1647                 " dist was %.2f, now %.2f\n",
1648                 stem_edge - hints->axis[dim].edges, stem_edge->fpos,
1649                 stem_edge->opos / 64.0, stem_edge->pos / 64.0,
1650                 dist / 64.0, fitted_width / 64.0 ));
1651   }
1652 
1653 
1654   /* Shift the coordinates of the `serif' edge by the same amount */
1655   /* as the corresponding `base' edge has been moved already.     */
1656 
1657   static void
af_cjk_align_serif_edge(AF_GlyphHints hints,AF_Edge base,AF_Edge serif)1658   af_cjk_align_serif_edge( AF_GlyphHints  hints,
1659                            AF_Edge        base,
1660                            AF_Edge        serif )
1661   {
1662     FT_UNUSED( hints );
1663 
1664     serif->pos = base->pos + ( serif->opos - base->opos );
1665   }
1666 
1667 
1668   /*************************************************************************/
1669   /*************************************************************************/
1670   /*************************************************************************/
1671   /****                                                                 ****/
1672   /****                    E D G E   H I N T I N G                      ****/
1673   /****                                                                 ****/
1674   /*************************************************************************/
1675   /*************************************************************************/
1676   /*************************************************************************/
1677 
1678 
1679 #define AF_LIGHT_MODE_MAX_HORZ_GAP    9
1680 #define AF_LIGHT_MODE_MAX_VERT_GAP   15
1681 #define AF_LIGHT_MODE_MAX_DELTA_ABS  14
1682 
1683 
1684   static FT_Pos
af_hint_normal_stem(AF_GlyphHints hints,AF_Edge edge,AF_Edge edge2,FT_Pos anchor,AF_Dimension dim)1685   af_hint_normal_stem( AF_GlyphHints  hints,
1686                        AF_Edge        edge,
1687                        AF_Edge        edge2,
1688                        FT_Pos         anchor,
1689                        AF_Dimension   dim )
1690   {
1691     FT_Pos  org_len, cur_len, org_center;
1692     FT_Pos  cur_pos1, cur_pos2;
1693     FT_Pos  d_off1, u_off1, d_off2, u_off2, delta;
1694     FT_Pos  offset;
1695     FT_Pos  threshold = 64;
1696 
1697 
1698     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1699     {
1700       if ( ( edge->flags  & AF_EDGE_ROUND ) &&
1701            ( edge2->flags & AF_EDGE_ROUND ) )
1702       {
1703         if ( dim == AF_DIMENSION_VERT )
1704           threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP;
1705         else
1706           threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP;
1707       }
1708       else
1709       {
1710         if ( dim == AF_DIMENSION_VERT )
1711           threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3;
1712         else
1713           threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3;
1714       }
1715     }
1716 
1717     org_len    = edge2->opos - edge->opos;
1718     cur_len    = af_cjk_compute_stem_width( hints, dim, org_len,
1719                                             edge->flags,
1720                                             edge2->flags );
1721 
1722     org_center = ( edge->opos + edge2->opos ) / 2 + anchor;
1723     cur_pos1   = org_center - cur_len / 2;
1724     cur_pos2   = cur_pos1 + cur_len;
1725     d_off1     = cur_pos1 - FT_PIX_FLOOR( cur_pos1 );
1726     d_off2     = cur_pos2 - FT_PIX_FLOOR( cur_pos2 );
1727     u_off1     = 64 - d_off1;
1728     u_off2     = 64 - d_off2;
1729     delta      = 0;
1730 
1731 
1732     if ( d_off1 == 0 || d_off2 == 0 )
1733       goto Exit;
1734 
1735     if ( cur_len <= threshold )
1736     {
1737       if ( d_off2 < cur_len )
1738       {
1739         if ( u_off1 <= d_off2 )
1740           delta =  u_off1;
1741         else
1742           delta = -d_off2;
1743       }
1744 
1745       goto Exit;
1746     }
1747 
1748     if ( threshold < 64 )
1749     {
1750       if ( d_off1 >= threshold || u_off1 >= threshold ||
1751            d_off2 >= threshold || u_off2 >= threshold )
1752         goto Exit;
1753     }
1754 
1755     offset = cur_len & 63;
1756 
1757     if ( offset < 32 )
1758     {
1759       if ( u_off1 <= offset || d_off2 <= offset )
1760         goto Exit;
1761     }
1762     else
1763       offset = 64 - threshold;
1764 
1765     d_off1 = threshold - u_off1;
1766     u_off1 = u_off1    - offset;
1767     u_off2 = threshold - d_off2;
1768     d_off2 = d_off2    - offset;
1769 
1770     if ( d_off1 <= u_off1 )
1771       u_off1 = -d_off1;
1772 
1773     if ( d_off2 <= u_off2 )
1774       u_off2 = -d_off2;
1775 
1776     if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) )
1777       delta = u_off1;
1778     else
1779       delta = u_off2;
1780 
1781   Exit:
1782 
1783 #if 1
1784     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
1785     {
1786       if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS )
1787         delta = AF_LIGHT_MODE_MAX_DELTA_ABS;
1788       else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS )
1789         delta = -AF_LIGHT_MODE_MAX_DELTA_ABS;
1790     }
1791 #endif
1792 
1793     cur_pos1 += delta;
1794 
1795     if ( edge->opos < edge2->opos )
1796     {
1797       edge->pos  = cur_pos1;
1798       edge2->pos = cur_pos1 + cur_len;
1799     }
1800     else
1801     {
1802       edge->pos  = cur_pos1 + cur_len;
1803       edge2->pos = cur_pos1;
1804     }
1805 
1806     return delta;
1807   }
1808 
1809 
1810   /* The main grid-fitting routine. */
1811 
1812   static void
af_cjk_hint_edges(AF_GlyphHints hints,AF_Dimension dim)1813   af_cjk_hint_edges( AF_GlyphHints  hints,
1814                      AF_Dimension   dim )
1815   {
1816     AF_AxisHints  axis       = &hints->axis[dim];
1817     AF_Edge       edges      = axis->edges;
1818     AF_Edge       edge_limit = edges + axis->num_edges;
1819     FT_PtrDist    n_edges;
1820     AF_Edge       edge;
1821     AF_Edge       anchor   = NULL;
1822     FT_Pos        delta    = 0;
1823     FT_Int        skipped  = 0;
1824     FT_Bool       has_last_stem = FALSE;
1825     FT_Pos        last_stem_pos = 0;
1826 
1827 #ifdef FT_DEBUG_LEVEL_TRACE
1828     FT_UInt       num_actions = 0;
1829 #endif
1830 
1831 
1832     FT_TRACE5(( "cjk %s edge hinting (style `%s')\n",
1833                 dim == AF_DIMENSION_VERT ? "horizontal" : "vertical",
1834                 af_style_names[hints->metrics->style_class->style] ));
1835 
1836     /* we begin by aligning all stems relative to the blue zone */
1837 
1838     if ( AF_HINTS_DO_BLUES( hints ) )
1839     {
1840       for ( edge = edges; edge < edge_limit; edge++ )
1841       {
1842         AF_Width  blue;
1843         AF_Edge   edge1, edge2;
1844 
1845 
1846         if ( edge->flags & AF_EDGE_DONE )
1847           continue;
1848 
1849         blue  = edge->blue_edge;
1850         edge1 = NULL;
1851         edge2 = edge->link;
1852 
1853         if ( blue )
1854         {
1855           edge1 = edge;
1856         }
1857         else if ( edge2 && edge2->blue_edge )
1858         {
1859           blue  = edge2->blue_edge;
1860           edge1 = edge2;
1861           edge2 = edge;
1862         }
1863 
1864         if ( !edge1 )
1865           continue;
1866 
1867 #ifdef FT_DEBUG_LEVEL_TRACE
1868         FT_TRACE5(( "  CJKBLUE: edge %ld @%d (opos=%.2f) snapped to %.2f,"
1869                     " was %.2f\n",
1870                     edge1 - edges, edge1->fpos, edge1->opos / 64.0,
1871                     blue->fit / 64.0, edge1->pos / 64.0 ));
1872 
1873         num_actions++;
1874 #endif
1875 
1876         edge1->pos    = blue->fit;
1877         edge1->flags |= AF_EDGE_DONE;
1878 
1879         if ( edge2 && !edge2->blue_edge )
1880         {
1881           af_cjk_align_linked_edge( hints, dim, edge1, edge2 );
1882           edge2->flags |= AF_EDGE_DONE;
1883 
1884 #ifdef FT_DEBUG_LEVEL_TRACE
1885           num_actions++;
1886 #endif
1887         }
1888 
1889         if ( !anchor )
1890           anchor = edge;
1891       }
1892     }
1893 
1894     /* now we align all stem edges. */
1895     for ( edge = edges; edge < edge_limit; edge++ )
1896     {
1897       AF_Edge  edge2;
1898 
1899 
1900       if ( edge->flags & AF_EDGE_DONE )
1901         continue;
1902 
1903       /* skip all non-stem edges */
1904       edge2 = edge->link;
1905       if ( !edge2 )
1906       {
1907         skipped++;
1908         continue;
1909       }
1910 
1911       /* Some CJK characters have so many stems that
1912        * the hinter is likely to merge two adjacent ones.
1913        * To solve this problem, if either edge of a stem
1914        * is too close to the previous one, we avoid
1915        * aligning the two edges, but rather interpolate
1916        * their locations at the end of this function in
1917        * order to preserve the space between the stems.
1918        */
1919       if ( has_last_stem                       &&
1920            ( edge->pos  < last_stem_pos + 64 ||
1921              edge2->pos < last_stem_pos + 64 ) )
1922       {
1923         skipped++;
1924         continue;
1925       }
1926 
1927       /* now align the stem */
1928 
1929       /* this should not happen, but it's better to be safe */
1930       if ( edge2->blue_edge )
1931       {
1932         FT_TRACE5(( "ASSERTION FAILED for edge %ld\n", edge2-edges ));
1933 
1934         af_cjk_align_linked_edge( hints, dim, edge2, edge );
1935         edge->flags |= AF_EDGE_DONE;
1936 
1937 #ifdef FT_DEBUG_LEVEL_TRACE
1938         num_actions++;
1939 #endif
1940 
1941         continue;
1942       }
1943 
1944       if ( edge2 < edge )
1945       {
1946         af_cjk_align_linked_edge( hints, dim, edge2, edge );
1947         edge->flags |= AF_EDGE_DONE;
1948 
1949 #ifdef FT_DEBUG_LEVEL_TRACE
1950         num_actions++;
1951 #endif
1952 
1953         /* We rarely reaches here it seems;
1954          * usually the two edges belonging
1955          * to one stem are marked as DONE together
1956          */
1957         has_last_stem = TRUE;
1958         last_stem_pos = edge->pos;
1959         continue;
1960       }
1961 
1962       if ( dim != AF_DIMENSION_VERT && !anchor )
1963       {
1964 
1965 #if 0
1966         if ( fixedpitch )
1967         {
1968           AF_Edge     left  = edge;
1969           AF_Edge     right = edge_limit - 1;
1970           AF_EdgeRec  left1, left2, right1, right2;
1971           FT_Pos      target, center1, center2;
1972           FT_Pos      delta1, delta2, d1, d2;
1973 
1974 
1975           while ( right > left && !right->link )
1976             right--;
1977 
1978           left1  = *left;
1979           left2  = *left->link;
1980           right1 = *right->link;
1981           right2 = *right;
1982 
1983           delta  = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2;
1984           target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16;
1985 
1986           delta1  = delta;
1987           delta1 += af_hint_normal_stem( hints, left, left->link,
1988                                          delta1, 0 );
1989 
1990           if ( left->link != right )
1991             af_hint_normal_stem( hints, right->link, right, delta1, 0 );
1992 
1993           center1 = left->pos + ( right->pos - left->pos ) / 2;
1994 
1995           if ( center1 >= target )
1996             delta2 = delta - 32;
1997           else
1998             delta2 = delta + 32;
1999 
2000           delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 );
2001 
2002           if ( delta1 != delta2 )
2003           {
2004             if ( left->link != right )
2005               af_hint_normal_stem( hints, &right1, &right2, delta2, 0 );
2006 
2007             center2 = left1.pos + ( right2.pos - left1.pos ) / 2;
2008 
2009             d1 = center1 - target;
2010             d2 = center2 - target;
2011 
2012             if ( FT_ABS( d2 ) < FT_ABS( d1 ) )
2013             {
2014               left->pos       = left1.pos;
2015               left->link->pos = left2.pos;
2016 
2017               if ( left->link != right )
2018               {
2019                 right->link->pos = right1.pos;
2020                 right->pos       = right2.pos;
2021               }
2022 
2023               delta1 = delta2;
2024             }
2025           }
2026 
2027           delta               = delta1;
2028           right->link->flags |= AF_EDGE_DONE;
2029           right->flags       |= AF_EDGE_DONE;
2030         }
2031         else
2032 
2033 #endif /* 0 */
2034 
2035           delta = af_hint_normal_stem( hints, edge, edge2, 0,
2036                                        AF_DIMENSION_HORZ );
2037       }
2038       else
2039         af_hint_normal_stem( hints, edge, edge2, delta, dim );
2040 
2041 #if 0
2042       printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n",
2043                edge - edges, edge2 - edges,
2044                ( edge->pos - edge->opos ) / 64.0,
2045                ( edge2->pos - edge2->opos ) / 64.0 );
2046 #endif
2047 
2048       anchor = edge;
2049       edge->flags  |= AF_EDGE_DONE;
2050       edge2->flags |= AF_EDGE_DONE;
2051       has_last_stem = TRUE;
2052       last_stem_pos = edge2->pos;
2053     }
2054 
2055     /* make sure that lowercase m's maintain their symmetry */
2056 
2057     /* In general, lowercase m's have six vertical edges if they are sans */
2058     /* serif, or twelve if they are with serifs.  This implementation is  */
2059     /* based on that assumption, and seems to work very well with most    */
2060     /* faces.  However, if for a certain face this assumption is not      */
2061     /* true, the m is just rendered like before.  In addition, any stem   */
2062     /* correction will only be applied to symmetrical glyphs (even if the */
2063     /* glyph is not an m), so the potential for unwanted distortion is    */
2064     /* relatively low.                                                    */
2065 
2066     /* We don't handle horizontal edges since we can't easily assure that */
2067     /* the third (lowest) stem aligns with the base line; it might end up */
2068     /* one pixel higher or lower.                                         */
2069 
2070     n_edges = edge_limit - edges;
2071     if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
2072     {
2073       AF_Edge  edge1, edge2, edge3;
2074       FT_Pos   dist1, dist2, span;
2075 
2076 
2077       if ( n_edges == 6 )
2078       {
2079         edge1 = edges;
2080         edge2 = edges + 2;
2081         edge3 = edges + 4;
2082       }
2083       else
2084       {
2085         edge1 = edges + 1;
2086         edge2 = edges + 5;
2087         edge3 = edges + 9;
2088       }
2089 
2090       dist1 = edge2->opos - edge1->opos;
2091       dist2 = edge3->opos - edge2->opos;
2092 
2093       span = dist1 - dist2;
2094       if ( span < 0 )
2095         span = -span;
2096 
2097       if ( edge1->link == edge1 + 1 &&
2098            edge2->link == edge2 + 1 &&
2099            edge3->link == edge3 + 1 && span < 8 )
2100       {
2101         delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
2102         edge3->pos -= delta;
2103         if ( edge3->link )
2104           edge3->link->pos -= delta;
2105 
2106         /* move the serifs along with the stem */
2107         if ( n_edges == 12 )
2108         {
2109           ( edges + 8 )->pos -= delta;
2110           ( edges + 11 )->pos -= delta;
2111         }
2112 
2113         edge3->flags |= AF_EDGE_DONE;
2114         if ( edge3->link )
2115           edge3->link->flags |= AF_EDGE_DONE;
2116       }
2117     }
2118 
2119     if ( !skipped )
2120       goto Exit;
2121 
2122     /*
2123      * now hint the remaining edges (serifs and single) in order
2124      * to complete our processing
2125      */
2126     for ( edge = edges; edge < edge_limit; edge++ )
2127     {
2128       if ( edge->flags & AF_EDGE_DONE )
2129         continue;
2130 
2131       if ( edge->serif )
2132       {
2133         af_cjk_align_serif_edge( hints, edge->serif, edge );
2134         edge->flags |= AF_EDGE_DONE;
2135         skipped--;
2136       }
2137     }
2138 
2139     if ( !skipped )
2140       goto Exit;
2141 
2142     for ( edge = edges; edge < edge_limit; edge++ )
2143     {
2144       AF_Edge  before, after;
2145 
2146 
2147       if ( edge->flags & AF_EDGE_DONE )
2148         continue;
2149 
2150       before = after = edge;
2151 
2152       while ( --before >= edges )
2153         if ( before->flags & AF_EDGE_DONE )
2154           break;
2155 
2156       while ( ++after < edge_limit )
2157         if ( after->flags & AF_EDGE_DONE )
2158           break;
2159 
2160       if ( before >= edges || after < edge_limit )
2161       {
2162         if ( before < edges )
2163           af_cjk_align_serif_edge( hints, after, edge );
2164         else if ( after >= edge_limit )
2165           af_cjk_align_serif_edge( hints, before, edge );
2166         else
2167         {
2168           if ( after->fpos == before->fpos )
2169             edge->pos = before->pos;
2170           else
2171             edge->pos = before->pos +
2172                         FT_MulDiv( edge->fpos - before->fpos,
2173                                    after->pos - before->pos,
2174                                    after->fpos - before->fpos );
2175         }
2176       }
2177     }
2178 
2179   Exit:
2180 
2181 #ifdef FT_DEBUG_LEVEL_TRACE
2182     if ( !num_actions )
2183       FT_TRACE5(( "  (none)\n" ));
2184     FT_TRACE5(( "\n" ));
2185 #endif
2186 
2187     return;
2188   }
2189 
2190 
2191   static void
af_cjk_align_edge_points(AF_GlyphHints hints,AF_Dimension dim)2192   af_cjk_align_edge_points( AF_GlyphHints  hints,
2193                             AF_Dimension   dim )
2194   {
2195     AF_AxisHints  axis       = & hints->axis[dim];
2196     AF_Edge       edges      = axis->edges;
2197     AF_Edge       edge_limit = edges + axis->num_edges;
2198     AF_Edge       edge;
2199     FT_Bool       snapping;
2200 
2201 
2202     snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ             &&
2203                           AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) )  ||
2204                         ( dim == AF_DIMENSION_VERT             &&
2205                           AF_LATIN_HINTS_DO_VERT_SNAP( hints ) )  );
2206 
2207     for ( edge = edges; edge < edge_limit; edge++ )
2208     {
2209       /* move the points of each segment     */
2210       /* in each edge to the edge's position */
2211       AF_Segment  seg = edge->first;
2212 
2213 
2214       if ( snapping )
2215       {
2216         do
2217         {
2218           AF_Point  point = seg->first;
2219 
2220 
2221           for (;;)
2222           {
2223             if ( dim == AF_DIMENSION_HORZ )
2224             {
2225               point->x      = edge->pos;
2226               point->flags |= AF_FLAG_TOUCH_X;
2227             }
2228             else
2229             {
2230               point->y      = edge->pos;
2231               point->flags |= AF_FLAG_TOUCH_Y;
2232             }
2233 
2234             if ( point == seg->last )
2235               break;
2236 
2237             point = point->next;
2238           }
2239 
2240           seg = seg->edge_next;
2241 
2242         } while ( seg != edge->first );
2243       }
2244       else
2245       {
2246         FT_Pos  delta = edge->pos - edge->opos;
2247 
2248 
2249         do
2250         {
2251           AF_Point  point = seg->first;
2252 
2253 
2254           for (;;)
2255           {
2256             if ( dim == AF_DIMENSION_HORZ )
2257             {
2258               point->x     += delta;
2259               point->flags |= AF_FLAG_TOUCH_X;
2260             }
2261             else
2262             {
2263               point->y     += delta;
2264               point->flags |= AF_FLAG_TOUCH_Y;
2265             }
2266 
2267             if ( point == seg->last )
2268               break;
2269 
2270             point = point->next;
2271           }
2272 
2273           seg = seg->edge_next;
2274 
2275         } while ( seg != edge->first );
2276       }
2277     }
2278   }
2279 
2280 
2281   /* Apply the complete hinting algorithm to a CJK glyph. */
2282 
2283   FT_LOCAL_DEF( FT_Error )
af_cjk_hints_apply(FT_UInt glyph_index,AF_GlyphHints hints,FT_Outline * outline,AF_CJKMetrics metrics)2284   af_cjk_hints_apply( FT_UInt        glyph_index,
2285                       AF_GlyphHints  hints,
2286                       FT_Outline*    outline,
2287                       AF_CJKMetrics  metrics )
2288   {
2289     FT_Error  error;
2290     int       dim;
2291 
2292     FT_UNUSED( metrics );
2293     FT_UNUSED( glyph_index );
2294 
2295 
2296     error = af_glyph_hints_reload( hints, outline );
2297     if ( error )
2298       goto Exit;
2299 
2300     /* analyze glyph outline */
2301     if ( AF_HINTS_DO_HORIZONTAL( hints ) )
2302     {
2303       error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ );
2304       if ( error )
2305         goto Exit;
2306 
2307       af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_HORZ );
2308     }
2309 
2310     if ( AF_HINTS_DO_VERTICAL( hints ) )
2311     {
2312       error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
2313       if ( error )
2314         goto Exit;
2315 
2316       af_cjk_hints_compute_blue_edges( hints, metrics, AF_DIMENSION_VERT );
2317     }
2318 
2319     /* grid-fit the outline */
2320     for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
2321     {
2322       if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
2323            ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
2324       {
2325 
2326 #ifdef AF_CONFIG_OPTION_USE_WARPER
2327         if ( dim == AF_DIMENSION_HORZ                                  &&
2328              metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL &&
2329              AF_HINTS_DO_WARP( hints )                                 )
2330         {
2331           AF_WarperRec  warper;
2332           FT_Fixed      scale;
2333           FT_Pos        delta;
2334 
2335 
2336           af_warper_compute( &warper, hints, (AF_Dimension)dim,
2337                              &scale, &delta );
2338           af_glyph_hints_scale_dim( hints, (AF_Dimension)dim,
2339                                     scale, delta );
2340           continue;
2341         }
2342 #endif /* AF_CONFIG_OPTION_USE_WARPER */
2343 
2344         af_cjk_hint_edges( hints, (AF_Dimension)dim );
2345         af_cjk_align_edge_points( hints, (AF_Dimension)dim );
2346         af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
2347         af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
2348       }
2349     }
2350 
2351     af_glyph_hints_save( hints, outline );
2352 
2353   Exit:
2354     return error;
2355   }
2356 
2357 
2358   /*************************************************************************/
2359   /*************************************************************************/
2360   /*****                                                               *****/
2361   /*****                C J K   S C R I P T   C L A S S                *****/
2362   /*****                                                               *****/
2363   /*************************************************************************/
2364   /*************************************************************************/
2365 
2366 
2367   AF_DEFINE_WRITING_SYSTEM_CLASS(
2368     af_cjk_writing_system_class,
2369 
2370     AF_WRITING_SYSTEM_CJK,
2371 
2372     sizeof ( AF_CJKMetricsRec ),
2373 
2374     (AF_WritingSystem_InitMetricsFunc) af_cjk_metrics_init,        /* style_metrics_init    */
2375     (AF_WritingSystem_ScaleMetricsFunc)af_cjk_metrics_scale,       /* style_metrics_scale   */
2376     (AF_WritingSystem_DoneMetricsFunc) NULL,                       /* style_metrics_done    */
2377     (AF_WritingSystem_GetStdWidthsFunc)af_cjk_get_standard_widths, /* style_metrics_getstdw */
2378 
2379     (AF_WritingSystem_InitHintsFunc)   af_cjk_hints_init,          /* style_hints_init      */
2380     (AF_WritingSystem_ApplyHintsFunc)  af_cjk_hints_apply          /* style_hints_apply     */
2381   )
2382 
2383 
2384 #else /* !AF_CONFIG_OPTION_CJK */
2385 
2386 
2387   AF_DEFINE_WRITING_SYSTEM_CLASS(
2388     af_cjk_writing_system_class,
2389 
2390     AF_WRITING_SYSTEM_CJK,
2391 
2392     sizeof ( AF_CJKMetricsRec ),
2393 
2394     (AF_WritingSystem_InitMetricsFunc) NULL, /* style_metrics_init    */
2395     (AF_WritingSystem_ScaleMetricsFunc)NULL, /* style_metrics_scale   */
2396     (AF_WritingSystem_DoneMetricsFunc) NULL, /* style_metrics_done    */
2397     (AF_WritingSystem_GetStdWidthsFunc)NULL, /* style_metrics_getstdw */
2398 
2399     (AF_WritingSystem_InitHintsFunc)   NULL, /* style_hints_init      */
2400     (AF_WritingSystem_ApplyHintsFunc)  NULL  /* style_hints_apply     */
2401   )
2402 
2403 
2404 #endif /* !AF_CONFIG_OPTION_CJK */
2405 
2406 
2407 /* END */
2408