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1 /* ATTENTION: This file doesn't compile.  It is only here as a reference */
2 /*            of an alternative latin hinting algorithm that was always  */
3 /*            marked as experimental.                                    */
4 
5 
6 /****************************************************************************
7  *
8  * aflatin2.c
9  *
10  *   Auto-fitter hinting routines for latin writing system (body).
11  *
12  * Copyright 2003-2018 by
13  * David Turner, Robert Wilhelm, and Werner Lemberg.
14  *
15  * This file is part of the FreeType project, and may only be used,
16  * modified, and distributed under the terms of the FreeType project
17  * license, LICENSE.TXT.  By continuing to use, modify, or distribute
18  * this file you indicate that you have read the license and
19  * understand and accept it fully.
20  *
21  */
22 
23 
24 #include FT_ADVANCES_H
25 
26 
27 #ifdef FT_OPTION_AUTOFIT2
28 
29 #include "afglobal.h"
30 #include "aflatin.h"
31 #include "aflatin2.h"
32 #include "aferrors.h"
33 
34 
35 #ifdef AF_CONFIG_OPTION_USE_WARPER
36 #include "afwarp.h"
37 #endif
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  trace_aflatin2
48 
49 
50   FT_LOCAL_DEF( FT_Error )
51   af_latin2_hints_compute_segments( AF_GlyphHints  hints,
52                                     AF_Dimension   dim );
53 
54   FT_LOCAL_DEF( void )
55   af_latin2_hints_link_segments( AF_GlyphHints  hints,
56                                  AF_Dimension   dim );
57 
58   /*************************************************************************/
59   /*************************************************************************/
60   /*****                                                               *****/
61   /*****            L A T I N   G L O B A L   M E T R I C S            *****/
62   /*****                                                               *****/
63   /*************************************************************************/
64   /*************************************************************************/
65 
66   FT_LOCAL_DEF( void )
af_latin2_metrics_init_widths(AF_LatinMetrics metrics,FT_Face face)67   af_latin2_metrics_init_widths( AF_LatinMetrics  metrics,
68                                  FT_Face          face )
69   {
70     /* scan the array of segments in each direction */
71     AF_GlyphHintsRec  hints[1];
72 
73 
74     af_glyph_hints_init( hints, face->memory );
75 
76     metrics->axis[AF_DIMENSION_HORZ].width_count = 0;
77     metrics->axis[AF_DIMENSION_VERT].width_count = 0;
78 
79     {
80       FT_Error             error;
81       FT_UInt              glyph_index;
82       int                  dim;
83       AF_LatinMetricsRec   dummy[1];
84       AF_Scaler            scaler = &dummy->root.scaler;
85 
86 
87       glyph_index = FT_Get_Char_Index(
88                       face,
89                       metrics->root.style_class->standard_char );
90       if ( glyph_index == 0 )
91         goto Exit;
92 
93       error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
94       if ( error || face->glyph->outline.n_points <= 0 )
95         goto Exit;
96 
97       FT_ZERO( dummy );
98 
99       dummy->units_per_em = metrics->units_per_em;
100       scaler->x_scale     = scaler->y_scale = 0x10000L;
101       scaler->x_delta     = scaler->y_delta = 0;
102       scaler->face        = face;
103       scaler->render_mode = FT_RENDER_MODE_NORMAL;
104       scaler->flags       = 0;
105 
106       af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy );
107 
108       error = af_glyph_hints_reload( hints, &face->glyph->outline );
109       if ( error )
110         goto Exit;
111 
112       for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
113       {
114         AF_LatinAxis  axis    = &metrics->axis[dim];
115         AF_AxisHints  axhints = &hints->axis[dim];
116         AF_Segment    seg, limit, link;
117         FT_UInt       num_widths = 0;
118 
119 
120         error = af_latin2_hints_compute_segments( hints,
121                                                  (AF_Dimension)dim );
122         if ( error )
123           goto Exit;
124 
125         af_latin2_hints_link_segments( hints,
126                                       (AF_Dimension)dim );
127 
128         seg   = axhints->segments;
129         limit = seg + axhints->num_segments;
130 
131         for ( ; seg < limit; seg++ )
132         {
133           link = seg->link;
134 
135           /* we only consider stem segments there! */
136           if ( link && link->link == seg && link > seg )
137           {
138             FT_Pos  dist;
139 
140 
141             dist = seg->pos - link->pos;
142             if ( dist < 0 )
143               dist = -dist;
144 
145             if ( num_widths < AF_LATIN_MAX_WIDTHS )
146               axis->widths[num_widths++].org = dist;
147           }
148         }
149 
150         af_sort_widths( num_widths, axis->widths );
151         axis->width_count = num_widths;
152       }
153 
154   Exit:
155       for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
156       {
157         AF_LatinAxis  axis = &metrics->axis[dim];
158         FT_Pos        stdw;
159 
160 
161         stdw = ( axis->width_count > 0 )
162                  ? axis->widths[0].org
163                  : AF_LATIN_CONSTANT( metrics, 50 );
164 
165         /* let's try 20% of the smallest width */
166         axis->edge_distance_threshold = stdw / 5;
167         axis->standard_width          = stdw;
168         axis->extra_light             = 0;
169       }
170     }
171 
172     af_glyph_hints_done( hints );
173   }
174 
175 
176 
177 #define AF_LATIN_MAX_TEST_CHARACTERS  12
178 
179 
180   static const char af_latin2_blue_chars[AF_LATIN_MAX_BLUES]
181                                         [AF_LATIN_MAX_TEST_CHARACTERS+1] =
182   {
183     "THEZOCQS",
184     "HEZLOCUS",
185     "fijkdbh",
186     "xzroesc",
187     "xzroesc",
188     "pqgjy"
189   };
190 
191 
192   static void
af_latin2_metrics_init_blues(AF_LatinMetrics metrics,FT_Face face)193   af_latin2_metrics_init_blues( AF_LatinMetrics  metrics,
194                                 FT_Face          face )
195   {
196     FT_Pos        flats [AF_LATIN_MAX_TEST_CHARACTERS];
197     FT_Pos        rounds[AF_LATIN_MAX_TEST_CHARACTERS];
198     FT_Int        num_flats;
199     FT_Int        num_rounds;
200     FT_Int        bb;
201     AF_LatinBlue  blue;
202     FT_Error      error;
203     AF_LatinAxis  axis  = &metrics->axis[AF_DIMENSION_VERT];
204     FT_GlyphSlot  glyph = face->glyph;
205 
206 
207     /* we compute the blues simply by loading each character from the     */
208     /* 'af_latin2_blue_chars[blues]' string, then compute its top-most or */
209     /* bottom-most points (depending on `AF_IS_TOP_BLUE')                 */
210 
211     FT_TRACE5(( "blue zones computation\n"
212                 "======================\n\n" ));
213 
214     for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
215     {
216       const char*  p     = af_latin2_blue_chars[bb];
217       const char*  limit = p + AF_LATIN_MAX_TEST_CHARACTERS;
218       FT_Pos*      blue_ref;
219       FT_Pos*      blue_shoot;
220 
221 
222       FT_TRACE5(( "blue zone %d:\n", bb ));
223 
224       num_flats  = 0;
225       num_rounds = 0;
226 
227       for ( ; p < limit && *p; p++ )
228       {
229         FT_UInt     glyph_index;
230         FT_Int      best_point, best_y, best_first, best_last;
231         FT_Vector*  points;
232         FT_Bool     round;
233 
234 
235         /* load the character in the face -- skip unknown or empty ones */
236         glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p );
237         if ( glyph_index == 0 )
238           continue;
239 
240         error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
241         if ( error || glyph->outline.n_points <= 0 )
242           continue;
243 
244         /* now compute min or max point indices and coordinates */
245         points      = glyph->outline.points;
246         best_point  = -1;
247         best_y      = 0;  /* make compiler happy */
248         best_first  = 0;  /* ditto */
249         best_last   = 0;  /* ditto */
250 
251         {
252           FT_Int  nn;
253           FT_Int  first = 0;
254           FT_Int  last  = -1;
255 
256 
257           for ( nn = 0; nn < glyph->outline.n_contours; first = last+1, nn++ )
258           {
259             FT_Int  old_best_point = best_point;
260             FT_Int  pp;
261 
262 
263             last = glyph->outline.contours[nn];
264 
265             /* Avoid single-point contours since they are never rasterized. */
266             /* In some fonts, they correspond to mark attachment points     */
267             /* which are way outside of the glyph's real outline.           */
268             if ( last == first )
269                 continue;
270 
271             if ( AF_LATIN_IS_TOP_BLUE( bb ) )
272             {
273               for ( pp = first; pp <= last; pp++ )
274                 if ( best_point < 0 || points[pp].y > best_y )
275                 {
276                   best_point = pp;
277                   best_y     = points[pp].y;
278                 }
279             }
280             else
281             {
282               for ( pp = first; pp <= last; pp++ )
283                 if ( best_point < 0 || points[pp].y < best_y )
284                 {
285                   best_point = pp;
286                   best_y     = points[pp].y;
287                 }
288             }
289 
290             if ( best_point != old_best_point )
291             {
292               best_first = first;
293               best_last  = last;
294             }
295           }
296           FT_TRACE5(( "  %c  %d", *p, best_y ));
297         }
298 
299         /* now check whether the point belongs to a straight or round   */
300         /* segment; we first need to find in which contour the extremum */
301         /* lies, then inspect its previous and next points              */
302         {
303           FT_Pos  best_x = points[best_point].x;
304           FT_Int  start, end, prev, next;
305           FT_Pos  dist;
306 
307 
308           /* now look for the previous and next points that are not on the */
309           /* same Y coordinate.  Threshold the `closeness'...              */
310           start = end = best_point;
311 
312           do
313           {
314             prev = start - 1;
315             if ( prev < best_first )
316               prev = best_last;
317 
318             dist = FT_ABS( points[prev].y - best_y );
319             /* accept a small distance or a small angle (both values are */
320             /* heuristic; value 20 corresponds to approx. 2.9 degrees)   */
321             if ( dist > 5 )
322               if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist )
323                 break;
324 
325             start = prev;
326 
327           } while ( start != best_point );
328 
329           do
330           {
331             next = end + 1;
332             if ( next > best_last )
333               next = best_first;
334 
335             dist = FT_ABS( points[next].y - best_y );
336             if ( dist > 5 )
337               if ( FT_ABS( points[next].x - best_x ) <= 20 * dist )
338                 break;
339 
340             end = next;
341 
342           } while ( end != best_point );
343 
344           /* now, set the `round' flag depending on the segment's kind */
345           round = FT_BOOL(
346             FT_CURVE_TAG( glyph->outline.tags[start] ) != FT_CURVE_TAG_ON ||
347             FT_CURVE_TAG( glyph->outline.tags[ end ] ) != FT_CURVE_TAG_ON );
348 
349           FT_TRACE5(( " (%s)\n", round ? "round" : "flat" ));
350         }
351 
352         if ( round )
353           rounds[num_rounds++] = best_y;
354         else
355           flats[num_flats++]   = best_y;
356       }
357 
358       if ( num_flats == 0 && num_rounds == 0 )
359       {
360         /*
361          * we couldn't find a single glyph to compute this blue zone,
362          * we will simply ignore it then
363          */
364         FT_TRACE5(( "  empty\n" ));
365         continue;
366       }
367 
368       /* we have computed the contents of the `rounds' and `flats' tables, */
369       /* now determine the reference and overshoot position of the blue -- */
370       /* we simply take the median value after a simple sort               */
371       af_sort_pos( num_rounds, rounds );
372       af_sort_pos( num_flats,  flats );
373 
374       blue       = & axis->blues[axis->blue_count];
375       blue_ref   = & blue->ref.org;
376       blue_shoot = & blue->shoot.org;
377 
378       axis->blue_count++;
379 
380       if ( num_flats == 0 )
381       {
382         *blue_ref   =
383         *blue_shoot = rounds[num_rounds / 2];
384       }
385       else if ( num_rounds == 0 )
386       {
387         *blue_ref   =
388         *blue_shoot = flats[num_flats / 2];
389       }
390       else
391       {
392         *blue_ref   = flats[num_flats / 2];
393         *blue_shoot = rounds[num_rounds / 2];
394       }
395 
396       /* there are sometimes problems: if the overshoot position of top     */
397       /* zones is under its reference position, or the opposite for bottom  */
398       /* zones.  We must thus check everything there and correct the errors */
399       if ( *blue_shoot != *blue_ref )
400       {
401         FT_Pos   ref      = *blue_ref;
402         FT_Pos   shoot    = *blue_shoot;
403         FT_Bool  over_ref = FT_BOOL( shoot > ref );
404 
405 
406         if ( AF_LATIN_IS_TOP_BLUE( bb ) ^ over_ref )
407         {
408           *blue_ref   =
409           *blue_shoot = ( shoot + ref ) / 2;
410 
411           FT_TRACE5(( "  [overshoot smaller than reference,"
412                       " taking mean value]\n" ));
413         }
414       }
415 
416       blue->flags = 0;
417       if ( AF_LATIN_IS_TOP_BLUE( bb ) )
418         blue->flags |= AF_LATIN_BLUE_TOP;
419 
420       /*
421        * The following flag is used later to adjust the y and x scales
422        * in order to optimize the pixel grid alignment of the top of small
423        * letters.
424        */
425       if ( AF_LATIN_IS_X_HEIGHT_BLUE( bb ) )
426         blue->flags |= AF_LATIN_BLUE_ADJUSTMENT;
427 
428       FT_TRACE5(( "    -> reference = %ld\n"
429                   "       overshoot = %ld\n",
430                   *blue_ref, *blue_shoot ));
431     }
432 
433     return;
434   }
435 
436 
437   FT_LOCAL_DEF( void )
af_latin2_metrics_check_digits(AF_LatinMetrics metrics,FT_Face face)438   af_latin2_metrics_check_digits( AF_LatinMetrics  metrics,
439                                   FT_Face          face )
440   {
441     FT_UInt   i;
442     FT_Bool   started = 0, same_width = 1;
443     FT_Fixed  advance, old_advance = 0;
444 
445 
446     /* check whether all ASCII digits have the same advance width; */
447     /* digit `0' is 0x30 in all supported charmaps                 */
448     for ( i = 0x30; i <= 0x39; i++ )
449     {
450       FT_UInt  glyph_index;
451 
452 
453       glyph_index = FT_Get_Char_Index( face, i );
454       if ( glyph_index == 0 )
455         continue;
456 
457       if ( FT_Get_Advance( face, glyph_index,
458                            FT_LOAD_NO_SCALE         |
459                            FT_LOAD_NO_HINTING       |
460                            FT_LOAD_IGNORE_TRANSFORM,
461                            &advance ) )
462         continue;
463 
464       if ( started )
465       {
466         if ( advance != old_advance )
467         {
468           same_width = 0;
469           break;
470         }
471       }
472       else
473       {
474         old_advance = advance;
475         started     = 1;
476       }
477     }
478 
479     metrics->root.digits_have_same_width = same_width;
480   }
481 
482 
483   FT_LOCAL_DEF( FT_Error )
af_latin2_metrics_init(AF_LatinMetrics metrics,FT_Face face)484   af_latin2_metrics_init( AF_LatinMetrics  metrics,
485                           FT_Face          face )
486   {
487     FT_Error    error  = FT_Err_Ok;
488     FT_CharMap  oldmap = face->charmap;
489     FT_UInt     ee;
490 
491     static const FT_Encoding  latin_encodings[] =
492     {
493       FT_ENCODING_UNICODE,
494       FT_ENCODING_APPLE_ROMAN,
495       FT_ENCODING_ADOBE_STANDARD,
496       FT_ENCODING_ADOBE_LATIN_1,
497       FT_ENCODING_NONE  /* end of list */
498     };
499 
500 
501     metrics->units_per_em = face->units_per_EM;
502 
503     /* do we have a latin charmap in there? */
504     for ( ee = 0; latin_encodings[ee] != FT_ENCODING_NONE; ee++ )
505     {
506       error = FT_Select_Charmap( face, latin_encodings[ee] );
507       if ( !error )
508         break;
509     }
510 
511     if ( !error )
512     {
513       af_latin2_metrics_init_widths( metrics, face );
514       af_latin2_metrics_init_blues( metrics, face );
515       af_latin2_metrics_check_digits( metrics, face );
516     }
517 
518     FT_Set_Charmap( face, oldmap );
519     return FT_Err_Ok;
520   }
521 
522 
523   static void
af_latin2_metrics_scale_dim(AF_LatinMetrics metrics,AF_Scaler scaler,AF_Dimension dim)524   af_latin2_metrics_scale_dim( AF_LatinMetrics  metrics,
525                                AF_Scaler        scaler,
526                                AF_Dimension     dim )
527   {
528     FT_Fixed      scale;
529     FT_Pos        delta;
530     AF_LatinAxis  axis;
531     FT_UInt       nn;
532 
533 
534     if ( dim == AF_DIMENSION_HORZ )
535     {
536       scale = scaler->x_scale;
537       delta = scaler->x_delta;
538     }
539     else
540     {
541       scale = scaler->y_scale;
542       delta = scaler->y_delta;
543     }
544 
545     axis = &metrics->axis[dim];
546 
547     if ( axis->org_scale == scale && axis->org_delta == delta )
548       return;
549 
550     axis->org_scale = scale;
551     axis->org_delta = delta;
552 
553     /*
554      * correct Y scale to optimize the alignment of the top of small
555      * letters to the pixel grid
556      */
557     if ( dim == AF_DIMENSION_VERT )
558     {
559       AF_LatinAxis  vaxis = &metrics->axis[AF_DIMENSION_VERT];
560       AF_LatinBlue  blue = NULL;
561 
562 
563       for ( nn = 0; nn < vaxis->blue_count; nn++ )
564       {
565         if ( vaxis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT )
566         {
567           blue = &vaxis->blues[nn];
568           break;
569         }
570       }
571 
572       if ( blue )
573       {
574         FT_Pos   scaled;
575         FT_Pos   threshold;
576         FT_Pos   fitted;
577         FT_UInt  limit;
578         FT_UInt  ppem;
579 
580 
581         scaled    = FT_MulFix( blue->shoot.org, scaler->y_scale );
582         ppem      = metrics->root.scaler.face->size->metrics.x_ppem;
583         limit     = metrics->root.globals->increase_x_height;
584         threshold = 40;
585 
586         /* if the `increase-x-height' property is active, */
587         /* we round up much more often                    */
588         if ( limit                                 &&
589              ppem <= limit                         &&
590              ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN )
591           threshold = 52;
592 
593         fitted = ( scaled + threshold ) & ~63;
594 
595 #if 1
596         if ( scaled != fitted )
597         {
598           scale = FT_MulDiv( scale, fitted, scaled );
599           FT_TRACE5(( "== scaled x-top = %.2g"
600                       "  fitted = %.2g, scaling = %.4g\n",
601                       scaled / 64.0, fitted / 64.0,
602                       ( fitted * 1.0 ) / scaled ));
603         }
604 #endif
605       }
606     }
607 
608     axis->scale = scale;
609     axis->delta = delta;
610 
611     if ( dim == AF_DIMENSION_HORZ )
612     {
613       metrics->root.scaler.x_scale = scale;
614       metrics->root.scaler.x_delta = delta;
615     }
616     else
617     {
618       metrics->root.scaler.y_scale = scale;
619       metrics->root.scaler.y_delta = delta;
620     }
621 
622     /* scale the standard widths */
623     for ( nn = 0; nn < axis->width_count; nn++ )
624     {
625       AF_Width  width = axis->widths + nn;
626 
627 
628       width->cur = FT_MulFix( width->org, scale );
629       width->fit = width->cur;
630     }
631 
632     /* an extra-light axis corresponds to a standard width that is */
633     /* smaller than 5/8 pixels                                     */
634     axis->extra_light =
635       (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 );
636 
637     if ( dim == AF_DIMENSION_VERT )
638     {
639       /* scale the blue zones */
640       for ( nn = 0; nn < axis->blue_count; nn++ )
641       {
642         AF_LatinBlue  blue = &axis->blues[nn];
643         FT_Pos        dist;
644 
645 
646         blue->ref.cur   = FT_MulFix( blue->ref.org, scale ) + delta;
647         blue->ref.fit   = blue->ref.cur;
648         blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
649         blue->shoot.fit = blue->shoot.cur;
650         blue->flags    &= ~AF_LATIN_BLUE_ACTIVE;
651 
652         /* a blue zone is only active if it is less than 3/4 pixels tall */
653         dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
654         if ( dist <= 48 && dist >= -48 )
655         {
656           FT_Pos  delta1, delta2;
657 
658           delta1 = blue->shoot.org - blue->ref.org;
659           delta2 = delta1;
660           if ( delta1 < 0 )
661             delta2 = -delta2;
662 
663           delta2 = FT_MulFix( delta2, scale );
664 
665           if ( delta2 < 32 )
666             delta2 = 0;
667           else if ( delta2 < 64 )
668             delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
669           else
670             delta2 = FT_PIX_ROUND( delta2 );
671 
672           if ( delta1 < 0 )
673             delta2 = -delta2;
674 
675           blue->ref.fit   = FT_PIX_ROUND( blue->ref.cur );
676           blue->shoot.fit = blue->ref.fit + delta2;
677 
678           FT_TRACE5(( ">> activating blue zone %d:"
679                       "  ref.cur=%.2g ref.fit=%.2g"
680                       "  shoot.cur=%.2g shoot.fit=%.2g\n",
681                       nn, blue->ref.cur / 64.0, blue->ref.fit / 64.0,
682                       blue->shoot.cur / 64.0, blue->shoot.fit / 64.0 ));
683 
684           blue->flags |= AF_LATIN_BLUE_ACTIVE;
685         }
686       }
687     }
688   }
689 
690 
691   FT_LOCAL_DEF( void )
af_latin2_metrics_scale(AF_LatinMetrics metrics,AF_Scaler scaler)692   af_latin2_metrics_scale( AF_LatinMetrics  metrics,
693                            AF_Scaler        scaler )
694   {
695     metrics->root.scaler.render_mode = scaler->render_mode;
696     metrics->root.scaler.face        = scaler->face;
697     metrics->root.scaler.flags       = scaler->flags;
698 
699     af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
700     af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
701   }
702 
703 
704   /* Extract standard_width from writing system/script specific */
705   /* metrics class.                                             */
706 
707   FT_LOCAL_DEF( void )
af_latin2_get_standard_widths(AF_LatinMetrics metrics,FT_Pos * stdHW,FT_Pos * stdVW)708   af_latin2_get_standard_widths( AF_LatinMetrics  metrics,
709                                  FT_Pos*          stdHW,
710                                  FT_Pos*          stdVW )
711   {
712     if ( stdHW )
713       *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width;
714 
715     if ( stdVW )
716       *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width;
717   }
718 
719 
720   /*************************************************************************/
721   /*************************************************************************/
722   /*****                                                               *****/
723   /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
724   /*****                                                               *****/
725   /*************************************************************************/
726   /*************************************************************************/
727 
728 #define  SORT_SEGMENTS
729 
730   FT_LOCAL_DEF( FT_Error )
af_latin2_hints_compute_segments(AF_GlyphHints hints,AF_Dimension dim)731   af_latin2_hints_compute_segments( AF_GlyphHints  hints,
732                                     AF_Dimension   dim )
733   {
734     AF_AxisHints  axis          = &hints->axis[dim];
735     FT_Memory     memory        = hints->memory;
736     FT_Error      error         = FT_Err_Ok;
737     AF_Segment    segment       = NULL;
738     AF_SegmentRec seg0;
739     AF_Point*     contour       = hints->contours;
740     AF_Point*     contour_limit = contour + hints->num_contours;
741     AF_Direction  major_dir, segment_dir;
742 
743 
744     FT_ZERO( &seg0 );
745     seg0.score = 32000;
746     seg0.flags = AF_EDGE_NORMAL;
747 
748     major_dir   = (AF_Direction)FT_ABS( axis->major_dir );
749     segment_dir = major_dir;
750 
751     axis->num_segments = 0;
752 
753     /* set up (u,v) in each point */
754     if ( dim == AF_DIMENSION_HORZ )
755     {
756       AF_Point  point = hints->points;
757       AF_Point  limit = point + hints->num_points;
758 
759 
760       for ( ; point < limit; point++ )
761       {
762         point->u = point->fx;
763         point->v = point->fy;
764       }
765     }
766     else
767     {
768       AF_Point  point = hints->points;
769       AF_Point  limit = point + hints->num_points;
770 
771 
772       for ( ; point < limit; point++ )
773       {
774         point->u = point->fy;
775         point->v = point->fx;
776       }
777     }
778 
779     /* do each contour separately */
780     for ( ; contour < contour_limit; contour++ )
781     {
782       AF_Point  point   =  contour[0];
783       AF_Point  start   =  point;
784       AF_Point  last    =  point->prev;
785 
786 
787       if ( point == last )  /* skip singletons -- just in case */
788         continue;
789 
790       /* already on an edge ?, backtrack to find its start */
791       if ( FT_ABS( point->in_dir ) == major_dir )
792       {
793         point = point->prev;
794 
795         while ( point->in_dir == start->in_dir )
796           point = point->prev;
797       }
798       else  /* otherwise, find first segment start, if any */
799       {
800         while ( FT_ABS( point->out_dir ) != major_dir )
801         {
802           point = point->next;
803 
804           if ( point == start )
805             goto NextContour;
806         }
807       }
808 
809       start = point;
810 
811       for  (;;)
812       {
813         AF_Point  first;
814         FT_Pos    min_u, min_v, max_u, max_v;
815 
816         /* we're at the start of a new segment */
817         FT_ASSERT( FT_ABS( point->out_dir ) == major_dir &&
818                            point->in_dir != point->out_dir );
819         first = point;
820 
821         min_u = max_u = point->u;
822         min_v = max_v = point->v;
823 
824         point = point->next;
825 
826         while ( point->out_dir == first->out_dir )
827         {
828           point = point->next;
829 
830           if ( point->u < min_u )
831             min_u = point->u;
832 
833           if ( point->u > max_u )
834             max_u = point->u;
835         }
836 
837         if ( point->v < min_v )
838           min_v = point->v;
839 
840         if ( point->v > max_v )
841           max_v = point->v;
842 
843         /* record new segment */
844         error = af_axis_hints_new_segment( axis, memory, &segment );
845         if ( error )
846           goto Exit;
847 
848         segment[0]         = seg0;
849         segment->dir       = first->out_dir;
850         segment->first     = first;
851         segment->last      = point;
852         segment->pos       = (FT_Short)( ( min_u + max_u ) >> 1 );
853         segment->min_coord = (FT_Short) min_v;
854         segment->max_coord = (FT_Short) max_v;
855         segment->height    = (FT_Short)( max_v - min_v );
856 
857         /* a segment is round if it doesn't have successive */
858         /* on-curve points.                                 */
859         {
860           AF_Point  pt   = first;
861           AF_Point  last = point;
862           FT_UInt   f0   = pt->flags & AF_FLAG_CONTROL;
863           FT_UInt   f1;
864 
865 
866           segment->flags &= ~AF_EDGE_ROUND;
867 
868           for ( ; pt != last; f0 = f1 )
869           {
870             pt = pt->next;
871             f1 = pt->flags & AF_FLAG_CONTROL;
872 
873             if ( !f0 && !f1 )
874               break;
875 
876             if ( pt == last )
877               segment->flags |= AF_EDGE_ROUND;
878           }
879         }
880 
881        /* this can happen in the case of a degenerate contour
882         * e.g. a 2-point vertical contour
883         */
884         if ( point == start )
885           break;
886 
887         /* jump to the start of the next segment, if any */
888         while ( FT_ABS( point->out_dir ) != major_dir )
889         {
890           point = point->next;
891 
892           if ( point == start )
893             goto NextContour;
894         }
895       }
896 
897     NextContour:
898       ;
899     } /* contours */
900 
901     /* now slightly increase the height of segments when this makes */
902     /* sense -- this is used to better detect and ignore serifs     */
903     {
904       AF_Segment  segments     = axis->segments;
905       AF_Segment  segments_end = segments + axis->num_segments;
906 
907 
908       for ( segment = segments; segment < segments_end; segment++ )
909       {
910         AF_Point  first   = segment->first;
911         AF_Point  last    = segment->last;
912         AF_Point  p;
913         FT_Pos    first_v = first->v;
914         FT_Pos    last_v  = last->v;
915 
916 
917         if ( first_v < last_v )
918         {
919           p = first->prev;
920           if ( p->v < first_v )
921             segment->height = (FT_Short)( segment->height +
922                                           ( ( first_v - p->v ) >> 1 ) );
923 
924           p = last->next;
925           if ( p->v > last_v )
926             segment->height = (FT_Short)( segment->height +
927                                           ( ( p->v - last_v ) >> 1 ) );
928         }
929         else
930         {
931           p = first->prev;
932           if ( p->v > first_v )
933             segment->height = (FT_Short)( segment->height +
934                                           ( ( p->v - first_v ) >> 1 ) );
935 
936           p = last->next;
937           if ( p->v < last_v )
938             segment->height = (FT_Short)( segment->height +
939                                           ( ( last_v - p->v ) >> 1 ) );
940         }
941       }
942     }
943 
944 #ifdef AF_SORT_SEGMENTS
945    /* place all segments with a negative direction to the start
946     * of the array, used to speed up segment linking later...
947     */
948     {
949       AF_Segment  segments = axis->segments;
950       FT_UInt     count    = axis->num_segments;
951       FT_UInt     ii, jj;
952 
953       for ( ii = 0; ii < count; ii++ )
954       {
955         if ( segments[ii].dir > 0 )
956         {
957           for ( jj = ii + 1; jj < count; jj++ )
958           {
959             if ( segments[jj].dir < 0 )
960             {
961               AF_SegmentRec  tmp;
962 
963 
964               tmp          = segments[ii];
965               segments[ii] = segments[jj];
966               segments[jj] = tmp;
967 
968               break;
969             }
970           }
971 
972           if ( jj == count )
973             break;
974         }
975       }
976       axis->mid_segments = ii;
977     }
978 #endif
979 
980   Exit:
981     return error;
982   }
983 
984 
985   FT_LOCAL_DEF( void )
af_latin2_hints_link_segments(AF_GlyphHints hints,AF_Dimension dim)986   af_latin2_hints_link_segments( AF_GlyphHints  hints,
987                                  AF_Dimension   dim )
988   {
989     AF_AxisHints  axis          = &hints->axis[dim];
990     AF_Segment    segments      = axis->segments;
991     AF_Segment    segment_limit = segments + axis->num_segments;
992 #ifdef AF_SORT_SEGMENTS
993     AF_Segment    segment_mid   = segments + axis->mid_segments;
994 #endif
995     FT_Pos        len_threshold, len_score;
996     AF_Segment    seg1, seg2;
997 
998 
999     len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
1000     if ( len_threshold == 0 )
1001       len_threshold = 1;
1002 
1003     len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 );
1004 
1005 #ifdef AF_SORT_SEGMENTS
1006     for ( seg1 = segments; seg1 < segment_mid; seg1++ )
1007     {
1008       if ( seg1->dir != axis->major_dir )
1009         continue;
1010 
1011       for ( seg2 = segment_mid; seg2 < segment_limit; seg2++ )
1012 #else
1013     /* now compare each segment to the others */
1014     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
1015     {
1016       if ( seg1->dir != axis->major_dir )
1017         continue;
1018 
1019       for ( seg2 = segments; seg2 < segment_limit; seg2++ )
1020         if ( seg1->dir + seg2->dir == 0 && seg2->pos > seg1->pos )
1021 #endif
1022         {
1023           FT_Pos  pos1 = seg1->pos;
1024           FT_Pos  pos2 = seg2->pos;
1025           FT_Pos  dist = pos2 - pos1;
1026 
1027 
1028           if ( dist < 0 )
1029             continue;
1030 
1031           {
1032             FT_Pos  min = seg1->min_coord;
1033             FT_Pos  max = seg1->max_coord;
1034             FT_Pos  len, score;
1035 
1036 
1037             if ( min < seg2->min_coord )
1038               min = seg2->min_coord;
1039 
1040             if ( max > seg2->max_coord )
1041               max = seg2->max_coord;
1042 
1043             len = max - min;
1044             if ( len >= len_threshold )
1045             {
1046               score = dist + len_score / len;
1047               if ( score < seg1->score )
1048               {
1049                 seg1->score = score;
1050                 seg1->link  = seg2;
1051               }
1052 
1053               if ( score < seg2->score )
1054               {
1055                 seg2->score = score;
1056                 seg2->link  = seg1;
1057               }
1058             }
1059           }
1060         }
1061     }
1062 #if 0
1063     }
1064 #endif
1065 
1066     /* now, compute the `serif' segments */
1067     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
1068     {
1069       seg2 = seg1->link;
1070 
1071       if ( seg2 )
1072       {
1073         if ( seg2->link != seg1 )
1074         {
1075           seg1->link  = NULL;
1076           seg1->serif = seg2->link;
1077         }
1078       }
1079     }
1080   }
1081 
1082 
1083   FT_LOCAL_DEF( FT_Error )
af_latin2_hints_compute_edges(AF_GlyphHints hints,AF_Dimension dim)1084   af_latin2_hints_compute_edges( AF_GlyphHints  hints,
1085                                  AF_Dimension   dim )
1086   {
1087     AF_AxisHints  axis   = &hints->axis[dim];
1088     FT_Error      error  = FT_Err_Ok;
1089     FT_Memory     memory = hints->memory;
1090     AF_LatinAxis  laxis  = &((AF_LatinMetrics)hints->metrics)->axis[dim];
1091 
1092     AF_Segment    segments      = axis->segments;
1093     AF_Segment    segment_limit = segments + axis->num_segments;
1094     AF_Segment    seg;
1095 
1096     AF_Direction  up_dir;
1097     FT_Fixed      scale;
1098     FT_Pos        edge_distance_threshold;
1099     FT_Pos        segment_length_threshold;
1100 
1101 
1102     axis->num_edges = 0;
1103 
1104     scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
1105                                          : hints->y_scale;
1106 
1107     up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP
1108                                           : AF_DIR_RIGHT;
1109 
1110     /*
1111      * We want to ignore very small (mostly serif) segments, we do that
1112      * by ignoring those that whose length is less than a given fraction
1113      * of the standard width. If there is no standard width, we ignore
1114      * those that are less than a given size in pixels
1115      *
1116      * also, unlink serif segments that are linked to segments farther
1117      * than 50% of the standard width
1118      */
1119     if ( dim == AF_DIMENSION_HORZ )
1120     {
1121       if ( laxis->width_count > 0 )
1122         segment_length_threshold = ( laxis->standard_width * 10 ) >> 4;
1123       else
1124         segment_length_threshold = FT_DivFix( 64, hints->y_scale );
1125     }
1126     else
1127       segment_length_threshold = 0;
1128 
1129     /**********************************************************************
1130      *
1131      * We will begin by generating a sorted table of edges for the
1132      * current direction.  To do so, we simply scan each segment and try
1133      * to find an edge in our table that corresponds to its position.
1134      *
1135      * If no edge is found, we create and insert a new edge in the
1136      * sorted table.  Otherwise, we simply add the segment to the edge's
1137      * list which will be processed in the second step to compute the
1138      * edge's properties.
1139      *
1140      * Note that the edges table is sorted along the segment/edge
1141      * position.
1142      *
1143      */
1144 
1145     edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
1146                                          scale );
1147     if ( edge_distance_threshold > 64 / 4 )
1148       edge_distance_threshold = 64 / 4;
1149 
1150     edge_distance_threshold = FT_DivFix( edge_distance_threshold,
1151                                          scale );
1152 
1153     for ( seg = segments; seg < segment_limit; seg++ )
1154     {
1155       AF_Edge  found = NULL;
1156       FT_Int   ee;
1157 
1158 
1159       if ( seg->height < segment_length_threshold )
1160         continue;
1161 
1162       /* A special case for serif edges: If they are smaller than */
1163       /* 1.5 pixels we ignore them.                               */
1164       if ( seg->serif )
1165       {
1166         FT_Pos  dist = seg->serif->pos - seg->pos;
1167 
1168 
1169         if ( dist < 0 )
1170           dist = -dist;
1171 
1172         if ( dist >= laxis->standard_width >> 1 )
1173         {
1174           /* unlink this serif, it is too distant from its reference stem */
1175           seg->serif = NULL;
1176         }
1177         else if ( 2*seg->height < 3 * segment_length_threshold )
1178           continue;
1179       }
1180 
1181       /* look for an edge corresponding to the segment */
1182       for ( ee = 0; ee < axis->num_edges; ee++ )
1183       {
1184         AF_Edge  edge = axis->edges + ee;
1185         FT_Pos   dist;
1186 
1187 
1188         dist = seg->pos - edge->fpos;
1189         if ( dist < 0 )
1190           dist = -dist;
1191 
1192         if ( dist < edge_distance_threshold && edge->dir == seg->dir )
1193         {
1194           found = edge;
1195           break;
1196         }
1197       }
1198 
1199       if ( !found )
1200       {
1201         AF_Edge   edge;
1202 
1203 
1204         /* insert a new edge in the list and */
1205         /* sort according to the position    */
1206         error = af_axis_hints_new_edge( axis, seg->pos, seg->dir, 0,
1207                                         memory, &edge );
1208         if ( error )
1209           goto Exit;
1210 
1211         /* add the segment to the new edge's list */
1212         FT_ZERO( edge );
1213 
1214         edge->first    = seg;
1215         edge->last     = seg;
1216         edge->dir      = seg->dir;
1217         edge->fpos     = seg->pos;
1218         edge->opos     = FT_MulFix( seg->pos, scale );
1219         edge->pos      = edge->opos;
1220         seg->edge_next = seg;
1221       }
1222       else
1223       {
1224         /* if an edge was found, simply add the segment to the edge's */
1225         /* list                                                       */
1226         seg->edge_next         = found->first;
1227         found->last->edge_next = seg;
1228         found->last            = seg;
1229       }
1230     }
1231 
1232 
1233     /**********************************************************************
1234      *
1235      * Good, we will now compute each edge's properties according to
1236      * segments found on its position.  Basically, these are:
1237      *
1238      * - edge's main direction
1239      * - stem edge, serif edge or both (which defaults to stem then)
1240      * - rounded edge, straight or both (which defaults to straight)
1241      * - link for edge
1242      *
1243      */
1244 
1245     /* first of all, set the `edge' field in each segment -- this is */
1246     /* required in order to compute edge links                       */
1247 
1248     /*
1249      * Note that removing this loop and setting the `edge' field of each
1250      * segment directly in the code above slows down execution speed for
1251      * some reasons on platforms like the Sun.
1252      */
1253     {
1254       AF_Edge  edges      = axis->edges;
1255       AF_Edge  edge_limit = edges + axis->num_edges;
1256       AF_Edge  edge;
1257 
1258 
1259       for ( edge = edges; edge < edge_limit; edge++ )
1260       {
1261         seg = edge->first;
1262         if ( seg )
1263           do
1264           {
1265             seg->edge = edge;
1266             seg       = seg->edge_next;
1267 
1268           } while ( seg != edge->first );
1269       }
1270 
1271       /* now, compute each edge properties */
1272       for ( edge = edges; edge < edge_limit; edge++ )
1273       {
1274         FT_Int  is_round    = 0;  /* does it contain round segments?    */
1275         FT_Int  is_straight = 0;  /* does it contain straight segments? */
1276 #if 0
1277         FT_Pos  ups         = 0;  /* number of upwards segments         */
1278         FT_Pos  downs       = 0;  /* number of downwards segments       */
1279 #endif
1280 
1281 
1282         seg = edge->first;
1283 
1284         do
1285         {
1286           FT_Bool  is_serif;
1287 
1288 
1289           /* check for roundness of segment */
1290           if ( seg->flags & AF_EDGE_ROUND )
1291             is_round++;
1292           else
1293             is_straight++;
1294 
1295 #if 0
1296           /* check for segment direction */
1297           if ( seg->dir == up_dir )
1298             ups   += seg->max_coord-seg->min_coord;
1299           else
1300             downs += seg->max_coord-seg->min_coord;
1301 #endif
1302 
1303           /* check for links -- if seg->serif is set, then seg->link must */
1304           /* be ignored                                                   */
1305           is_serif = (FT_Bool)( seg->serif               &&
1306                                 seg->serif->edge         &&
1307                                 seg->serif->edge != edge );
1308 
1309           if ( ( seg->link && seg->link->edge ) || is_serif )
1310           {
1311             AF_Edge     edge2;
1312             AF_Segment  seg2;
1313 
1314 
1315             edge2 = edge->link;
1316             seg2  = seg->link;
1317 
1318             if ( is_serif )
1319             {
1320               seg2  = seg->serif;
1321               edge2 = edge->serif;
1322             }
1323 
1324             if ( edge2 )
1325             {
1326               FT_Pos  edge_delta;
1327               FT_Pos  seg_delta;
1328 
1329 
1330               edge_delta = edge->fpos - edge2->fpos;
1331               if ( edge_delta < 0 )
1332                 edge_delta = -edge_delta;
1333 
1334               seg_delta = seg->pos - seg2->pos;
1335               if ( seg_delta < 0 )
1336                 seg_delta = -seg_delta;
1337 
1338               if ( seg_delta < edge_delta )
1339                 edge2 = seg2->edge;
1340             }
1341             else
1342               edge2 = seg2->edge;
1343 
1344             if ( is_serif )
1345             {
1346               edge->serif   = edge2;
1347               edge2->flags |= AF_EDGE_SERIF;
1348             }
1349             else
1350               edge->link  = edge2;
1351           }
1352 
1353           seg = seg->edge_next;
1354 
1355         } while ( seg != edge->first );
1356 
1357         /* set the round/straight flags */
1358         edge->flags = AF_EDGE_NORMAL;
1359 
1360         if ( is_round > 0 && is_round >= is_straight )
1361           edge->flags |= AF_EDGE_ROUND;
1362 
1363 #if 0
1364         /* set the edge's main direction */
1365         edge->dir = AF_DIR_NONE;
1366 
1367         if ( ups > downs )
1368           edge->dir = (FT_Char)up_dir;
1369 
1370         else if ( ups < downs )
1371           edge->dir = (FT_Char)-up_dir;
1372 
1373         else if ( ups == downs )
1374           edge->dir = 0;  /* both up and down! */
1375 #endif
1376 
1377         /* gets rid of serifs if link is set                */
1378         /* XXX: This gets rid of many unpleasant artefacts! */
1379         /*      Example: the `c' in cour.pfa at size 13     */
1380 
1381         if ( edge->serif && edge->link )
1382           edge->serif = NULL;
1383       }
1384     }
1385 
1386   Exit:
1387     return error;
1388   }
1389 
1390 
1391   FT_LOCAL_DEF( FT_Error )
af_latin2_hints_detect_features(AF_GlyphHints hints,AF_Dimension dim)1392   af_latin2_hints_detect_features( AF_GlyphHints  hints,
1393                                    AF_Dimension   dim )
1394   {
1395     FT_Error  error;
1396 
1397 
1398     error = af_latin2_hints_compute_segments( hints, dim );
1399     if ( !error )
1400     {
1401       af_latin2_hints_link_segments( hints, dim );
1402 
1403       error = af_latin2_hints_compute_edges( hints, dim );
1404     }
1405     return error;
1406   }
1407 
1408 
1409   static void
af_latin2_hints_compute_blue_edges(AF_GlyphHints hints,AF_LatinMetrics metrics)1410   af_latin2_hints_compute_blue_edges( AF_GlyphHints    hints,
1411                                       AF_LatinMetrics  metrics )
1412   {
1413     AF_AxisHints  axis       = &hints->axis[AF_DIMENSION_VERT];
1414     AF_Edge       edge       = axis->edges;
1415     AF_Edge       edge_limit = edge + axis->num_edges;
1416     AF_LatinAxis  latin      = &metrics->axis[AF_DIMENSION_VERT];
1417     FT_Fixed      scale      = latin->scale;
1418     FT_Pos        best_dist0;  /* initial threshold */
1419 
1420 
1421     /* compute the initial threshold as a fraction of the EM size */
1422     best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
1423 
1424     if ( best_dist0 > 64 / 2 )
1425       best_dist0 = 64 / 2;
1426 
1427     /* compute which blue zones are active, i.e. have their scaled */
1428     /* size < 3/4 pixels                                           */
1429 
1430     /* for each horizontal edge search the blue zone which is closest */
1431     for ( ; edge < edge_limit; edge++ )
1432     {
1433       FT_Int    bb;
1434       AF_Width  best_blue = NULL;
1435       FT_Pos    best_dist = best_dist0;
1436 
1437       for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
1438       {
1439         AF_LatinBlue  blue = latin->blues + bb;
1440         FT_Bool       is_top_blue, is_major_dir;
1441 
1442 
1443         /* skip inactive blue zones (i.e., those that are too small) */
1444         if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) )
1445           continue;
1446 
1447         /* if it is a top zone, check for right edges -- if it is a bottom */
1448         /* zone, check for left edges                                      */
1449         /*                                                                 */
1450         /* of course, that's for TrueType                                  */
1451         is_top_blue  = (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 );
1452         is_major_dir = FT_BOOL( edge->dir == axis->major_dir );
1453 
1454         /* if it is a top zone, the edge must be against the major    */
1455         /* direction; if it is a bottom zone, it must be in the major */
1456         /* direction                                                  */
1457         if ( is_top_blue ^ is_major_dir )
1458         {
1459           FT_Pos     dist;
1460           AF_Width   compare;
1461 
1462 
1463           /* if it's a rounded edge, compare it to the overshoot position */
1464           /* if it's a flat edge, compare it to the reference position    */
1465           if ( edge->flags & AF_EDGE_ROUND )
1466             compare = &blue->shoot;
1467           else
1468             compare = &blue->ref;
1469 
1470           dist = edge->fpos - compare->org;
1471           if ( dist < 0 )
1472             dist = -dist;
1473 
1474           dist = FT_MulFix( dist, scale );
1475           if ( dist < best_dist )
1476           {
1477             best_dist = dist;
1478             best_blue = compare;
1479           }
1480 
1481 #if 0
1482           /* now, compare it to the overshoot position if the edge is     */
1483           /* rounded, and if the edge is over the reference position of a */
1484           /* top zone, or under the reference position of a bottom zone   */
1485           if ( edge->flags & AF_EDGE_ROUND && dist != 0 )
1486           {
1487             FT_Bool  is_under_ref = FT_BOOL( edge->fpos < blue->ref.org );
1488 
1489 
1490             if ( is_top_blue ^ is_under_ref )
1491             {
1492               blue = latin->blues + bb;
1493               dist = edge->fpos - blue->shoot.org;
1494               if ( dist < 0 )
1495                 dist = -dist;
1496 
1497               dist = FT_MulFix( dist, scale );
1498               if ( dist < best_dist )
1499               {
1500                 best_dist = dist;
1501                 best_blue = & blue->shoot;
1502               }
1503             }
1504           }
1505 #endif
1506         }
1507       }
1508 
1509       if ( best_blue )
1510         edge->blue_edge = best_blue;
1511     }
1512   }
1513 
1514 
1515   static FT_Error
af_latin2_hints_init(AF_GlyphHints hints,AF_LatinMetrics metrics)1516   af_latin2_hints_init( AF_GlyphHints    hints,
1517                         AF_LatinMetrics  metrics )
1518   {
1519     FT_Render_Mode  mode;
1520     FT_UInt32       scaler_flags, other_flags;
1521     FT_Face         face = metrics->root.scaler.face;
1522 
1523 
1524     af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics );
1525 
1526     /*
1527      * correct x_scale and y_scale if needed, since they may have
1528      * been modified `af_latin2_metrics_scale_dim' above
1529      */
1530     hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
1531     hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
1532     hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
1533     hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
1534 
1535     /* compute flags depending on render mode, etc. */
1536     mode = metrics->root.scaler.render_mode;
1537 
1538 #if 0 /* #ifdef AF_CONFIG_OPTION_USE_WARPER */
1539     if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
1540       metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
1541 #endif
1542 
1543     scaler_flags = hints->scaler_flags;
1544     other_flags  = 0;
1545 
1546     /*
1547      * We snap the width of vertical stems for the monochrome and
1548      * horizontal LCD rendering targets only.
1549      */
1550     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
1551       other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
1552 
1553     /*
1554      * We snap the width of horizontal stems for the monochrome and
1555      * vertical LCD rendering targets only.
1556      */
1557     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
1558       other_flags |= AF_LATIN_HINTS_VERT_SNAP;
1559 
1560     /*
1561      * We adjust stems to full pixels unless in `light' or `lcd' mode.
1562      */
1563     if ( mode != FT_RENDER_MODE_LIGHT && mode != FT_RENDER_MODE_LCD )
1564       other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
1565 
1566     if ( mode == FT_RENDER_MODE_MONO )
1567       other_flags |= AF_LATIN_HINTS_MONO;
1568 
1569     /*
1570      * In `light' or `lcd' mode we disable horizontal hinting completely.
1571      * We also do it if the face is italic.
1572      */
1573     if ( mode == FT_RENDER_MODE_LIGHT || mode == FT_RENDER_MODE_LCD ||
1574          ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0          )
1575       scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL;
1576 
1577 #ifdef AF_CONFIG_OPTION_USE_WARPER
1578     /* get (global) warper flag */
1579     if ( !metrics->root.globals->module->warping )
1580       scaler_flags |= AF_SCALER_FLAG_NO_WARPER;
1581 #endif
1582 
1583     hints->scaler_flags = scaler_flags;
1584     hints->other_flags  = other_flags;
1585 
1586     return 0;
1587   }
1588 
1589 
1590   /*************************************************************************/
1591   /*************************************************************************/
1592   /*****                                                               *****/
1593   /*****        L A T I N   G L Y P H   G R I D - F I T T I N G        *****/
1594   /*****                                                               *****/
1595   /*************************************************************************/
1596   /*************************************************************************/
1597 
1598   /* snap a given width in scaled coordinates to one of the */
1599   /* current standard widths                                */
1600 
1601   static FT_Pos
af_latin2_snap_width(AF_Width widths,FT_UInt count,FT_Pos width)1602   af_latin2_snap_width( AF_Width  widths,
1603                         FT_UInt   count,
1604                         FT_Pos    width )
1605   {
1606     FT_UInt  n;
1607     FT_Pos   best      = 64 + 32 + 2;
1608     FT_Pos   reference = width;
1609     FT_Pos   scaled;
1610 
1611 
1612     for ( n = 0; n < count; n++ )
1613     {
1614       FT_Pos  w;
1615       FT_Pos  dist;
1616 
1617 
1618       w = widths[n].cur;
1619       dist = width - w;
1620       if ( dist < 0 )
1621         dist = -dist;
1622       if ( dist < best )
1623       {
1624         best      = dist;
1625         reference = w;
1626       }
1627     }
1628 
1629     scaled = FT_PIX_ROUND( reference );
1630 
1631     if ( width >= reference )
1632     {
1633       if ( width < scaled + 48 )
1634         width = reference;
1635     }
1636     else
1637     {
1638       if ( width > scaled - 48 )
1639         width = reference;
1640     }
1641 
1642     return width;
1643   }
1644 
1645 
1646   /* compute the snapped width of a given stem */
1647 
1648   static FT_Pos
af_latin2_compute_stem_width(AF_GlyphHints hints,AF_Dimension dim,FT_Pos width,FT_UInt base_flags,FT_UInt stem_flags)1649   af_latin2_compute_stem_width( AF_GlyphHints  hints,
1650                                 AF_Dimension   dim,
1651                                 FT_Pos         width,
1652                                 FT_UInt        base_flags,
1653                                 FT_UInt        stem_flags )
1654   {
1655     AF_LatinMetrics  metrics  = (AF_LatinMetrics) hints->metrics;
1656     AF_LatinAxis     axis     = & metrics->axis[dim];
1657     FT_Pos           dist     = width;
1658     FT_Int           sign     = 0;
1659     FT_Int           vertical = ( dim == AF_DIMENSION_VERT );
1660 
1661     FT_UNUSED( base_flags );
1662 
1663 
1664     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ||
1665           axis->extra_light                      )
1666       return width;
1667 
1668     if ( dist < 0 )
1669     {
1670       dist = -width;
1671       sign = 1;
1672     }
1673 
1674     if ( (  vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
1675          ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
1676     {
1677       /* smooth hinting process: very lightly quantize the stem width */
1678 
1679       /* leave the widths of serifs alone */
1680 
1681       if ( ( stem_flags & AF_EDGE_SERIF ) && vertical && ( dist < 3 * 64 ) )
1682         goto Done_Width;
1683 
1684 #if 0
1685       else if ( ( base_flags & AF_EDGE_ROUND ) )
1686       {
1687         if ( dist < 80 )
1688           dist = 64;
1689       }
1690       else if ( dist < 56 )
1691         dist = 56;
1692 #endif
1693       if ( axis->width_count > 0 )
1694       {
1695         FT_Pos  delta;
1696 
1697 
1698         /* compare to standard width */
1699         if ( axis->width_count > 0 )
1700         {
1701           delta = dist - axis->widths[0].cur;
1702 
1703           if ( delta < 0 )
1704             delta = -delta;
1705 
1706           if ( delta < 40 )
1707           {
1708             dist = axis->widths[0].cur;
1709             if ( dist < 48 )
1710               dist = 48;
1711 
1712             goto Done_Width;
1713           }
1714         }
1715 
1716         if ( dist < 3 * 64 )
1717         {
1718           delta  = dist & 63;
1719           dist  &= -64;
1720 
1721           if ( delta < 10 )
1722             dist += delta;
1723 
1724           else if ( delta < 32 )
1725             dist += 10;
1726 
1727           else if ( delta < 54 )
1728             dist += 54;
1729 
1730           else
1731             dist += delta;
1732         }
1733         else
1734           dist = ( dist + 32 ) & ~63;
1735       }
1736     }
1737     else
1738     {
1739       /* strong hinting process: snap the stem width to integer pixels */
1740       FT_Pos  org_dist = dist;
1741 
1742 
1743       dist = af_latin2_snap_width( axis->widths, axis->width_count, dist );
1744 
1745       if ( vertical )
1746       {
1747         /* in the case of vertical hinting, always round */
1748         /* the stem heights to integer pixels            */
1749 
1750         if ( dist >= 64 )
1751           dist = ( dist + 16 ) & ~63;
1752         else
1753           dist = 64;
1754       }
1755       else
1756       {
1757         if ( AF_LATIN_HINTS_DO_MONO( hints ) )
1758         {
1759           /* monochrome horizontal hinting: snap widths to integer pixels */
1760           /* with a different threshold                                   */
1761 
1762           if ( dist < 64 )
1763             dist = 64;
1764           else
1765             dist = ( dist + 32 ) & ~63;
1766         }
1767         else
1768         {
1769           /* for horizontal anti-aliased hinting, we adopt a more subtle */
1770           /* approach: we strengthen small stems, round stems whose size */
1771           /* is between 1 and 2 pixels to an integer, otherwise nothing  */
1772 
1773           if ( dist < 48 )
1774             dist = ( dist + 64 ) >> 1;
1775 
1776           else if ( dist < 128 )
1777           {
1778             /* We only round to an integer width if the corresponding */
1779             /* distortion is less than 1/4 pixel.  Otherwise this     */
1780             /* makes everything worse since the diagonals, which are  */
1781             /* not hinted, appear a lot bolder or thinner than the    */
1782             /* vertical stems.                                        */
1783 
1784             FT_Int  delta;
1785 
1786 
1787             dist = ( dist + 22 ) & ~63;
1788             delta = dist - org_dist;
1789             if ( delta < 0 )
1790               delta = -delta;
1791 
1792             if ( delta >= 16 )
1793             {
1794               dist = org_dist;
1795               if ( dist < 48 )
1796                 dist = ( dist + 64 ) >> 1;
1797             }
1798           }
1799           else
1800             /* round otherwise to prevent color fringes in LCD mode */
1801             dist = ( dist + 32 ) & ~63;
1802         }
1803       }
1804     }
1805 
1806   Done_Width:
1807     if ( sign )
1808       dist = -dist;
1809 
1810     return dist;
1811   }
1812 
1813 
1814   /* align one stem edge relative to the previous stem edge */
1815 
1816   static void
af_latin2_align_linked_edge(AF_GlyphHints hints,AF_Dimension dim,AF_Edge base_edge,AF_Edge stem_edge)1817   af_latin2_align_linked_edge( AF_GlyphHints  hints,
1818                                AF_Dimension   dim,
1819                                AF_Edge        base_edge,
1820                                AF_Edge        stem_edge )
1821   {
1822     FT_Pos  dist = stem_edge->opos - base_edge->opos;
1823 
1824     FT_Pos  fitted_width = af_latin2_compute_stem_width( hints, dim, dist,
1825                                                          base_edge->flags,
1826                                                          stem_edge->flags );
1827 
1828 
1829     stem_edge->pos = base_edge->pos + fitted_width;
1830 
1831     FT_TRACE5(( "LINK: edge %d (opos=%.2f) linked to (%.2f), "
1832                 "dist was %.2f, now %.2f\n",
1833                 stem_edge-hints->axis[dim].edges, stem_edge->opos / 64.0,
1834                 stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 ));
1835   }
1836 
1837 
1838   static void
af_latin2_align_serif_edge(AF_GlyphHints hints,AF_Edge base,AF_Edge serif)1839   af_latin2_align_serif_edge( AF_GlyphHints  hints,
1840                               AF_Edge        base,
1841                               AF_Edge        serif )
1842   {
1843     FT_UNUSED( hints );
1844 
1845     serif->pos = base->pos + ( serif->opos - base->opos );
1846   }
1847 
1848 
1849   /*************************************************************************/
1850   /*************************************************************************/
1851   /*************************************************************************/
1852   /****                                                                 ****/
1853   /****                    E D G E   H I N T I N G                      ****/
1854   /****                                                                 ****/
1855   /*************************************************************************/
1856   /*************************************************************************/
1857   /*************************************************************************/
1858 
1859 
1860   static void
af_latin2_hint_edges(AF_GlyphHints hints,AF_Dimension dim)1861   af_latin2_hint_edges( AF_GlyphHints  hints,
1862                         AF_Dimension   dim )
1863   {
1864     AF_AxisHints  axis       = &hints->axis[dim];
1865     AF_Edge       edges      = axis->edges;
1866     AF_Edge       edge_limit = edges + axis->num_edges;
1867     AF_Edge       edge;
1868     AF_Edge       anchor     = NULL;
1869     FT_Int        has_serifs = 0;
1870     FT_Pos        anchor_drift = 0;
1871 
1872 
1873 
1874     FT_TRACE5(( "==== hinting %s edges =====\n",
1875                 dim == AF_DIMENSION_HORZ ? "vertical" : "horizontal" ));
1876 
1877     /* we begin by aligning all stems relative to the blue zone */
1878     /* if needed -- that's only for horizontal edges            */
1879 
1880     if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) )
1881     {
1882       for ( edge = edges; edge < edge_limit; edge++ )
1883       {
1884         AF_Width  blue;
1885         AF_Edge   edge1, edge2;
1886 
1887 
1888         if ( edge->flags & AF_EDGE_DONE )
1889           continue;
1890 
1891         blue  = edge->blue_edge;
1892         edge1 = NULL;
1893         edge2 = edge->link;
1894 
1895         if ( blue )
1896         {
1897           edge1 = edge;
1898         }
1899         else if ( edge2 && edge2->blue_edge )
1900         {
1901           blue  = edge2->blue_edge;
1902           edge1 = edge2;
1903           edge2 = edge;
1904         }
1905 
1906         if ( !edge1 )
1907           continue;
1908 
1909         FT_TRACE5(( "BLUE: edge %d (opos=%.2f) snapped to (%.2f), "
1910                     "was (%.2f)\n",
1911                     edge1-edges, edge1->opos / 64.0, blue->fit / 64.0,
1912                     edge1->pos / 64.0 ));
1913 
1914         edge1->pos    = blue->fit;
1915         edge1->flags |= AF_EDGE_DONE;
1916 
1917         if ( edge2 && !edge2->blue_edge )
1918         {
1919           af_latin2_align_linked_edge( hints, dim, edge1, edge2 );
1920           edge2->flags |= AF_EDGE_DONE;
1921         }
1922 
1923         if ( !anchor )
1924         {
1925           anchor = edge;
1926 
1927           anchor_drift = ( anchor->pos - anchor->opos );
1928           if ( edge2 )
1929             anchor_drift = ( anchor_drift +
1930                              ( edge2->pos - edge2->opos ) ) >> 1;
1931         }
1932       }
1933     }
1934 
1935     /* now we will align all stem edges, trying to maintain the */
1936     /* relative order of stems in the glyph                     */
1937     for ( edge = edges; edge < edge_limit; edge++ )
1938     {
1939       AF_Edge  edge2;
1940 
1941 
1942       if ( edge->flags & AF_EDGE_DONE )
1943         continue;
1944 
1945       /* skip all non-stem edges */
1946       edge2 = edge->link;
1947       if ( !edge2 )
1948       {
1949         has_serifs++;
1950         continue;
1951       }
1952 
1953       /* now align the stem */
1954 
1955       /* this should not happen, but it's better to be safe */
1956       if ( edge2->blue_edge )
1957       {
1958         FT_TRACE5(( "ASSERTION FAILED for edge %d\n", edge2-edges ));
1959 
1960         af_latin2_align_linked_edge( hints, dim, edge2, edge );
1961         edge->flags |= AF_EDGE_DONE;
1962         continue;
1963       }
1964 
1965       if ( !anchor )
1966       {
1967         FT_Pos  org_len, org_center, cur_len;
1968         FT_Pos  cur_pos1, error1, error2, u_off, d_off;
1969 
1970 
1971         org_len = edge2->opos - edge->opos;
1972         cur_len = af_latin2_compute_stem_width( hints, dim, org_len,
1973                                                 edge->flags,
1974                                                 edge2->flags );
1975         if ( cur_len <= 64 )
1976           u_off = d_off = 32;
1977         else
1978         {
1979           u_off = 38;
1980           d_off = 26;
1981         }
1982 
1983         if ( cur_len < 96 )
1984         {
1985           org_center = edge->opos + ( org_len >> 1 );
1986 
1987           cur_pos1   = FT_PIX_ROUND( org_center );
1988 
1989           error1 = org_center - ( cur_pos1 - u_off );
1990           if ( error1 < 0 )
1991             error1 = -error1;
1992 
1993           error2 = org_center - ( cur_pos1 + d_off );
1994           if ( error2 < 0 )
1995             error2 = -error2;
1996 
1997           if ( error1 < error2 )
1998             cur_pos1 -= u_off;
1999           else
2000             cur_pos1 += d_off;
2001 
2002           edge->pos  = cur_pos1 - cur_len / 2;
2003           edge2->pos = edge->pos + cur_len;
2004         }
2005         else
2006           edge->pos = FT_PIX_ROUND( edge->opos );
2007 
2008         FT_TRACE5(( "ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)"
2009                     " snapped to (%.2f) (%.2f)\n",
2010                     edge-edges, edge->opos / 64.0,
2011                     edge2-edges, edge2->opos / 64.0,
2012                     edge->pos / 64.0, edge2->pos / 64.0 ));
2013         anchor = edge;
2014 
2015         edge->flags |= AF_EDGE_DONE;
2016 
2017         af_latin2_align_linked_edge( hints, dim, edge, edge2 );
2018 
2019         edge2->flags |= AF_EDGE_DONE;
2020 
2021         anchor_drift = ( ( anchor->pos - anchor->opos ) +
2022                          ( edge2->pos - edge2->opos ) ) >> 1;
2023 
2024         FT_TRACE5(( "DRIFT: %.2f\n", anchor_drift/64.0 ));
2025       }
2026       else
2027       {
2028         FT_Pos   org_pos, org_len, org_center, cur_center, cur_len;
2029         FT_Pos   org_left, org_right;
2030 
2031 
2032         org_pos    = edge->opos + anchor_drift;
2033         org_len    = edge2->opos - edge->opos;
2034         org_center = org_pos + ( org_len >> 1 );
2035 
2036         cur_len = af_latin2_compute_stem_width( hints, dim, org_len,
2037                                                 edge->flags,
2038                                                 edge2->flags );
2039 
2040         org_left  = org_pos + ( ( org_len - cur_len ) >> 1 );
2041         org_right = org_pos + ( ( org_len + cur_len ) >> 1 );
2042 
2043         FT_TRACE5(( "ALIGN: left=%.2f right=%.2f ",
2044                     org_left / 64.0, org_right / 64.0 ));
2045         cur_center = org_center;
2046 
2047         if ( edge2->flags & AF_EDGE_DONE )
2048         {
2049           FT_TRACE5(( "\n" ));
2050           edge->pos = edge2->pos - cur_len;
2051         }
2052         else
2053         {
2054          /* we want to compare several displacement, and choose
2055           * the one that increases fitness while minimizing
2056           * distortion as well
2057           */
2058           FT_Pos   displacements[6], scores[6], org, fit, delta;
2059           FT_UInt  count = 0;
2060 
2061           /* note: don't even try to fit tiny stems */
2062           if ( cur_len < 32 )
2063           {
2064             FT_TRACE5(( "tiny stem\n" ));
2065             goto AlignStem;
2066           }
2067 
2068           /* if the span is within a single pixel, don't touch it */
2069           if ( FT_PIX_FLOOR( org_left ) == FT_PIX_CEIL( org_right ) )
2070           {
2071             FT_TRACE5(( "single pixel stem\n" ));
2072             goto AlignStem;
2073           }
2074 
2075           if ( cur_len <= 96 )
2076           {
2077            /* we want to avoid the absolute worst case which is
2078             * when the left and right edges of the span each represent
2079             * about 50% of the gray. we'd better want to change this
2080             * to 25/75%, since this is much more pleasant to the eye with
2081             * very acceptable distortion
2082             */
2083             FT_Pos  frac_left  = org_left  & 63;
2084             FT_Pos  frac_right = org_right & 63;
2085 
2086             if ( frac_left  >= 22 && frac_left  <= 42 &&
2087                  frac_right >= 22 && frac_right <= 42 )
2088             {
2089               org = frac_left;
2090               fit = ( org <= 32 ) ? 16 : 48;
2091               delta = FT_ABS( fit - org );
2092               displacements[count] = fit - org;
2093               scores[count++]      = delta;
2094               FT_TRACE5(( "dispA=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2095 
2096               org = frac_right;
2097               fit = ( org <= 32 ) ? 16 : 48;
2098               delta = FT_ABS( fit - org );
2099               displacements[count] = fit - org;
2100               scores[count++]     = delta;
2101               FT_TRACE5(( "dispB=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2102             }
2103           }
2104 
2105           /* snapping the left edge to the grid */
2106           org   = org_left;
2107           fit   = FT_PIX_ROUND( org );
2108           delta = FT_ABS( fit - org );
2109           displacements[count] = fit - org;
2110           scores[count++]      = delta;
2111           FT_TRACE5(( "dispC=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2112 
2113           /* snapping the right edge to the grid */
2114           org   = org_right;
2115           fit   = FT_PIX_ROUND( org );
2116           delta = FT_ABS( fit - org );
2117           displacements[count] = fit - org;
2118           scores[count++]      = delta;
2119           FT_TRACE5(( "dispD=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2120 
2121           /* now find the best displacement */
2122           {
2123             FT_Pos  best_score = scores[0];
2124             FT_Pos  best_disp  = displacements[0];
2125             FT_UInt nn;
2126 
2127             for ( nn = 1; nn < count; nn++ )
2128             {
2129               if ( scores[nn] < best_score )
2130               {
2131                 best_score = scores[nn];
2132                 best_disp  = displacements[nn];
2133               }
2134             }
2135 
2136             cur_center = org_center + best_disp;
2137           }
2138           FT_TRACE5(( "\n" ));
2139         }
2140 
2141       AlignStem:
2142         edge->pos  = cur_center - ( cur_len >> 1 );
2143         edge2->pos = edge->pos + cur_len;
2144 
2145         FT_TRACE5(( "STEM1: %d (opos=%.2f) to %d (opos=%.2f)"
2146                     " snapped to (%.2f) and (%.2f),"
2147                     " org_len=%.2f cur_len=%.2f\n",
2148                     edge-edges, edge->opos / 64.0,
2149                     edge2-edges, edge2->opos / 64.0,
2150                     edge->pos / 64.0, edge2->pos / 64.0,
2151                     org_len / 64.0, cur_len / 64.0 ));
2152 
2153         edge->flags  |= AF_EDGE_DONE;
2154         edge2->flags |= AF_EDGE_DONE;
2155 
2156         if ( edge > edges && edge->pos < edge[-1].pos )
2157         {
2158           FT_TRACE5(( "BOUND: %d (pos=%.2f) to (%.2f)\n",
2159                       edge-edges, edge->pos / 64.0, edge[-1].pos / 64.0 ));
2160           edge->pos = edge[-1].pos;
2161         }
2162       }
2163     }
2164 
2165     /* make sure that lowercase m's maintain their symmetry */
2166 
2167     /* In general, lowercase m's have six vertical edges if they are sans */
2168     /* serif, or twelve if they are with serifs.  This implementation is  */
2169     /* based on that assumption, and seems to work very well with most    */
2170     /* faces.  However, if for a certain face this assumption is not      */
2171     /* true, the m is just rendered like before.  In addition, any stem   */
2172     /* correction will only be applied to symmetrical glyphs (even if the */
2173     /* glyph is not an m), so the potential for unwanted distortion is    */
2174     /* relatively low.                                                    */
2175 
2176     /* We don't handle horizontal edges since we can't easily assure that */
2177     /* the third (lowest) stem aligns with the base line; it might end up */
2178     /* one pixel higher or lower.                                         */
2179 
2180 #if 0
2181     {
2182       FT_Int  n_edges = edge_limit - edges;
2183 
2184 
2185       if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
2186       {
2187         AF_Edge  edge1, edge2, edge3;
2188         FT_Pos   dist1, dist2, span, delta;
2189 
2190 
2191         if ( n_edges == 6 )
2192         {
2193           edge1 = edges;
2194           edge2 = edges + 2;
2195           edge3 = edges + 4;
2196         }
2197         else
2198         {
2199           edge1 = edges + 1;
2200           edge2 = edges + 5;
2201           edge3 = edges + 9;
2202         }
2203 
2204         dist1 = edge2->opos - edge1->opos;
2205         dist2 = edge3->opos - edge2->opos;
2206 
2207         span = dist1 - dist2;
2208         if ( span < 0 )
2209           span = -span;
2210 
2211         if ( span < 8 )
2212         {
2213           delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
2214           edge3->pos -= delta;
2215           if ( edge3->link )
2216             edge3->link->pos -= delta;
2217 
2218           /* move the serifs along with the stem */
2219           if ( n_edges == 12 )
2220           {
2221             ( edges + 8 )->pos -= delta;
2222             ( edges + 11 )->pos -= delta;
2223           }
2224 
2225           edge3->flags |= AF_EDGE_DONE;
2226           if ( edge3->link )
2227             edge3->link->flags |= AF_EDGE_DONE;
2228         }
2229       }
2230     }
2231 #endif
2232 
2233     if ( has_serifs || !anchor )
2234     {
2235       /*
2236        * now hint the remaining edges (serifs and single) in order
2237        * to complete our processing
2238        */
2239       for ( edge = edges; edge < edge_limit; edge++ )
2240       {
2241         FT_Pos  delta;
2242 
2243 
2244         if ( edge->flags & AF_EDGE_DONE )
2245           continue;
2246 
2247         delta = 1000;
2248 
2249         if ( edge->serif )
2250         {
2251           delta = edge->serif->opos - edge->opos;
2252           if ( delta < 0 )
2253             delta = -delta;
2254         }
2255 
2256         if ( delta < 64 + 16 )
2257         {
2258           af_latin2_align_serif_edge( hints, edge->serif, edge );
2259           FT_TRACE5(( "SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)"
2260                       " aligned to (%.2f)\n",
2261                       edge-edges, edge->opos / 64.0,
2262                       edge->serif - edges, edge->serif->opos / 64.0,
2263                       edge->pos / 64.0 ));
2264         }
2265         else if ( !anchor )
2266         {
2267           FT_TRACE5(( "SERIF_ANCHOR: edge %d (opos=%.2f)"
2268                       " snapped to (%.2f)\n",
2269                       edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
2270           edge->pos = FT_PIX_ROUND( edge->opos );
2271           anchor    = edge;
2272         }
2273         else
2274         {
2275           AF_Edge  before, after;
2276 
2277 
2278           for ( before = edge - 1; before >= edges; before-- )
2279             if ( before->flags & AF_EDGE_DONE )
2280               break;
2281 
2282           for ( after = edge + 1; after < edge_limit; after++ )
2283             if ( after->flags & AF_EDGE_DONE )
2284               break;
2285 
2286           if ( before >= edges && before < edge   &&
2287                after < edge_limit && after > edge )
2288           {
2289             if ( after->opos == before->opos )
2290               edge->pos = before->pos;
2291             else
2292               edge->pos = before->pos +
2293                           FT_MulDiv( edge->opos - before->opos,
2294                                      after->pos - before->pos,
2295                                      after->opos - before->opos );
2296             FT_TRACE5(( "SERIF_LINK1: edge %d (opos=%.2f) snapped to (%.2f)"
2297                         " from %d (opos=%.2f)\n",
2298                         edge-edges, edge->opos / 64.0, edge->pos / 64.0,
2299                         before - edges, before->opos / 64.0 ));
2300           }
2301           else
2302           {
2303             edge->pos = anchor->pos +
2304                         ( ( edge->opos - anchor->opos + 16 ) & ~31 );
2305 
2306             FT_TRACE5(( "SERIF_LINK2: edge %d (opos=%.2f)"
2307                         " snapped to (%.2f)\n",
2308                         edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
2309           }
2310         }
2311 
2312         edge->flags |= AF_EDGE_DONE;
2313 
2314         if ( edge > edges && edge->pos < edge[-1].pos )
2315           edge->pos = edge[-1].pos;
2316 
2317         if ( edge + 1 < edge_limit        &&
2318              edge[1].flags & AF_EDGE_DONE &&
2319              edge->pos > edge[1].pos      )
2320           edge->pos = edge[1].pos;
2321       }
2322     }
2323   }
2324 
2325 
2326   static FT_Error
af_latin2_hints_apply(FT_UInt glyph_index,AF_GlyphHints hints,FT_Outline * outline,AF_LatinMetrics metrics)2327   af_latin2_hints_apply( FT_UInt          glyph_index,
2328                          AF_GlyphHints    hints,
2329                          FT_Outline*      outline,
2330                          AF_LatinMetrics  metrics )
2331   {
2332     FT_Error  error;
2333     int       dim;
2334 
2335     FT_UNUSED( glyph_index );
2336 
2337 
2338     error = af_glyph_hints_reload( hints, outline );
2339     if ( error )
2340       goto Exit;
2341 
2342     /* analyze glyph outline */
2343     if ( AF_HINTS_DO_HORIZONTAL( hints ) )
2344     {
2345       error = af_latin2_hints_detect_features( hints, AF_DIMENSION_HORZ );
2346       if ( error )
2347         goto Exit;
2348     }
2349 
2350     if ( AF_HINTS_DO_VERTICAL( hints ) )
2351     {
2352       error = af_latin2_hints_detect_features( hints, AF_DIMENSION_VERT );
2353       if ( error )
2354         goto Exit;
2355 
2356       af_latin2_hints_compute_blue_edges( hints, metrics );
2357     }
2358 
2359     /* grid-fit the outline */
2360     for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
2361     {
2362 #ifdef AF_CONFIG_OPTION_USE_WARPER
2363       if ( dim == AF_DIMENSION_HORZ                                  &&
2364            metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL &&
2365            AF_HINTS_DO_WARP( hints )                                 )
2366       {
2367         AF_WarperRec  warper;
2368         FT_Fixed      scale;
2369         FT_Pos        delta;
2370 
2371 
2372         af_warper_compute( &warper, hints, dim, &scale, &delta );
2373         af_glyph_hints_scale_dim( hints, dim, scale, delta );
2374         continue;
2375       }
2376 #endif /* AF_CONFIG_OPTION_USE_WARPER */
2377 
2378       if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
2379            ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
2380       {
2381         af_latin2_hint_edges( hints, (AF_Dimension)dim );
2382         af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim );
2383         af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
2384         af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
2385       }
2386     }
2387     af_glyph_hints_save( hints, outline );
2388 
2389   Exit:
2390     return error;
2391   }
2392 
2393 
2394   /*************************************************************************/
2395   /*************************************************************************/
2396   /*****                                                               *****/
2397   /*****              L A T I N   S C R I P T   C L A S S              *****/
2398   /*****                                                               *****/
2399   /*************************************************************************/
2400   /*************************************************************************/
2401 
2402 
2403   AF_DEFINE_WRITING_SYSTEM_CLASS(
2404     af_latin2_writing_system_class,
2405 
2406     AF_WRITING_SYSTEM_LATIN2,
2407 
2408     sizeof ( AF_LatinMetricsRec ),
2409 
2410     (AF_WritingSystem_InitMetricsFunc) af_latin2_metrics_init,        /* style_metrics_init    */
2411     (AF_WritingSystem_ScaleMetricsFunc)af_latin2_metrics_scale,       /* style_metrics_scale   */
2412     (AF_WritingSystem_DoneMetricsFunc) NULL,                          /* style_metrics_done    */
2413     (AF_WritingSystem_GetStdWidthsFunc)af_latin2_get_standard_widths, /* style_metrics_getstdw */
2414 
2415     (AF_WritingSystem_InitHintsFunc)   af_latin2_hints_init,          /* style_hints_init      */
2416     (AF_WritingSystem_ApplyHintsFunc)  af_latin2_hints_apply          /* style_hints_apply     */
2417   )
2418 
2419 #else /* !FT_OPTION_AUTOFIT2 */
2420 
2421   /* ANSI C doesn't like empty source files */
2422   typedef int  _af_latin2_dummy;
2423 
2424 #endif /* !FT_OPTION_AUTOFIT2 */
2425 
2426 
2427 /* END */
2428