1 /***************************************************************************/
2 /*                                                                         */
3 /*  aflatin2.c                                                             */
4 /*                                                                         */
5 /*    Auto-fitter hinting routines for latin writing system (body).        */
6 /*                                                                         */
7 /*  Copyright 2003-2015 by                                                 */
8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
9 /*                                                                         */
10 /*  This file is part of the FreeType project, and may only be used,       */
11 /*  modified, and distributed under the terms of the FreeType project      */
12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
13 /*  this file you indicate that you have read the license and              */
14 /*  understand and accept it fully.                                        */
15 /*                                                                         */
16 /***************************************************************************/
17 
18 
19 #include FT_ADVANCES_H
20 
21 #include "afglobal.h"
22 #include "aflatin.h"
23 #include "aflatin2.h"
24 #include "aferrors.h"
25 
26 
27 #ifdef AF_CONFIG_OPTION_USE_WARPER
28 #include "afwarp.h"
29 #endif
30 
31 
32   /*************************************************************************/
33   /*                                                                       */
34   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
35   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
36   /* messages during execution.                                            */
37   /*                                                                       */
38 #undef  FT_COMPONENT
39 #define FT_COMPONENT  trace_aflatin2
40 
41 
42   FT_LOCAL_DEF( FT_Error )
43   af_latin2_hints_compute_segments( AF_GlyphHints  hints,
44                                     AF_Dimension   dim );
45 
46   FT_LOCAL_DEF( void )
47   af_latin2_hints_link_segments( AF_GlyphHints  hints,
48                                  AF_Dimension   dim );
49 
50   /*************************************************************************/
51   /*************************************************************************/
52   /*****                                                               *****/
53   /*****            L A T I N   G L O B A L   M E T R I C S            *****/
54   /*****                                                               *****/
55   /*************************************************************************/
56   /*************************************************************************/
57 
58   FT_LOCAL_DEF( void )
af_latin2_metrics_init_widths(AF_LatinMetrics metrics,FT_Face face)59   af_latin2_metrics_init_widths( AF_LatinMetrics  metrics,
60                                  FT_Face          face )
61   {
62     /* scan the array of segments in each direction */
63     AF_GlyphHintsRec  hints[1];
64 
65 
66     af_glyph_hints_init( hints, face->memory );
67 
68     metrics->axis[AF_DIMENSION_HORZ].width_count = 0;
69     metrics->axis[AF_DIMENSION_VERT].width_count = 0;
70 
71     {
72       FT_Error             error;
73       FT_UInt              glyph_index;
74       int                  dim;
75       AF_LatinMetricsRec   dummy[1];
76       AF_Scaler            scaler = &dummy->root.scaler;
77 
78 
79       glyph_index = FT_Get_Char_Index(
80                       face,
81                       metrics->root.style_class->standard_char );
82       if ( glyph_index == 0 )
83         goto Exit;
84 
85       error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
86       if ( error || face->glyph->outline.n_points <= 0 )
87         goto Exit;
88 
89       FT_ZERO( dummy );
90 
91       dummy->units_per_em = metrics->units_per_em;
92       scaler->x_scale     = scaler->y_scale = 0x10000L;
93       scaler->x_delta     = scaler->y_delta = 0;
94       scaler->face        = face;
95       scaler->render_mode = FT_RENDER_MODE_NORMAL;
96       scaler->flags       = 0;
97 
98       af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy );
99 
100       error = af_glyph_hints_reload( hints, &face->glyph->outline );
101       if ( error )
102         goto Exit;
103 
104       for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
105       {
106         AF_LatinAxis  axis    = &metrics->axis[dim];
107         AF_AxisHints  axhints = &hints->axis[dim];
108         AF_Segment    seg, limit, link;
109         FT_UInt       num_widths = 0;
110 
111 
112         error = af_latin2_hints_compute_segments( hints,
113                                                  (AF_Dimension)dim );
114         if ( error )
115           goto Exit;
116 
117         af_latin2_hints_link_segments( hints,
118                                       (AF_Dimension)dim );
119 
120         seg   = axhints->segments;
121         limit = seg + axhints->num_segments;
122 
123         for ( ; seg < limit; seg++ )
124         {
125           link = seg->link;
126 
127           /* we only consider stem segments there! */
128           if ( link && link->link == seg && link > seg )
129           {
130             FT_Pos  dist;
131 
132 
133             dist = seg->pos - link->pos;
134             if ( dist < 0 )
135               dist = -dist;
136 
137             if ( num_widths < AF_LATIN_MAX_WIDTHS )
138               axis->widths[num_widths++].org = dist;
139           }
140         }
141 
142         af_sort_widths( num_widths, axis->widths );
143         axis->width_count = num_widths;
144       }
145 
146   Exit:
147       for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
148       {
149         AF_LatinAxis  axis = &metrics->axis[dim];
150         FT_Pos        stdw;
151 
152 
153         stdw = ( axis->width_count > 0 )
154                  ? axis->widths[0].org
155                  : AF_LATIN_CONSTANT( metrics, 50 );
156 
157         /* let's try 20% of the smallest width */
158         axis->edge_distance_threshold = stdw / 5;
159         axis->standard_width          = stdw;
160         axis->extra_light             = 0;
161       }
162     }
163 
164     af_glyph_hints_done( hints );
165   }
166 
167 
168 
169 #define AF_LATIN_MAX_TEST_CHARACTERS  12
170 
171 
172   static const char af_latin2_blue_chars[AF_LATIN_MAX_BLUES]
173                                         [AF_LATIN_MAX_TEST_CHARACTERS+1] =
174   {
175     "THEZOCQS",
176     "HEZLOCUS",
177     "fijkdbh",
178     "xzroesc",
179     "xzroesc",
180     "pqgjy"
181   };
182 
183 
184   static void
af_latin2_metrics_init_blues(AF_LatinMetrics metrics,FT_Face face)185   af_latin2_metrics_init_blues( AF_LatinMetrics  metrics,
186                                 FT_Face          face )
187   {
188     FT_Pos        flats [AF_LATIN_MAX_TEST_CHARACTERS];
189     FT_Pos        rounds[AF_LATIN_MAX_TEST_CHARACTERS];
190     FT_Int        num_flats;
191     FT_Int        num_rounds;
192     FT_Int        bb;
193     AF_LatinBlue  blue;
194     FT_Error      error;
195     AF_LatinAxis  axis  = &metrics->axis[AF_DIMENSION_VERT];
196     FT_GlyphSlot  glyph = face->glyph;
197 
198 
199     /* we compute the blues simply by loading each character from the     */
200     /* 'af_latin2_blue_chars[blues]' string, then compute its top-most or */
201     /* bottom-most points (depending on `AF_IS_TOP_BLUE')                 */
202 
203     FT_TRACE5(( "blue zones computation\n"
204                 "======================\n\n" ));
205 
206     for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
207     {
208       const char*  p     = af_latin2_blue_chars[bb];
209       const char*  limit = p + AF_LATIN_MAX_TEST_CHARACTERS;
210       FT_Pos*      blue_ref;
211       FT_Pos*      blue_shoot;
212 
213 
214       FT_TRACE5(( "blue zone %d:\n", bb ));
215 
216       num_flats  = 0;
217       num_rounds = 0;
218 
219       for ( ; p < limit && *p; p++ )
220       {
221         FT_UInt     glyph_index;
222         FT_Int      best_point, best_y, best_first, best_last;
223         FT_Vector*  points;
224         FT_Bool     round;
225 
226 
227         /* load the character in the face -- skip unknown or empty ones */
228         glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p );
229         if ( glyph_index == 0 )
230           continue;
231 
232         error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
233         if ( error || glyph->outline.n_points <= 0 )
234           continue;
235 
236         /* now compute min or max point indices and coordinates */
237         points      = glyph->outline.points;
238         best_point  = -1;
239         best_y      = 0;  /* make compiler happy */
240         best_first  = 0;  /* ditto */
241         best_last   = 0;  /* ditto */
242 
243         {
244           FT_Int  nn;
245           FT_Int  first = 0;
246           FT_Int  last  = -1;
247 
248 
249           for ( nn = 0; nn < glyph->outline.n_contours; first = last+1, nn++ )
250           {
251             FT_Int  old_best_point = best_point;
252             FT_Int  pp;
253 
254 
255             last = glyph->outline.contours[nn];
256 
257             /* Avoid single-point contours since they are never rasterized. */
258             /* In some fonts, they correspond to mark attachment points     */
259             /* which are way outside of the glyph's real outline.           */
260             if ( last == first )
261                 continue;
262 
263             if ( AF_LATIN_IS_TOP_BLUE( bb ) )
264             {
265               for ( pp = first; pp <= last; pp++ )
266                 if ( best_point < 0 || points[pp].y > best_y )
267                 {
268                   best_point = pp;
269                   best_y     = points[pp].y;
270                 }
271             }
272             else
273             {
274               for ( pp = first; pp <= last; pp++ )
275                 if ( best_point < 0 || points[pp].y < best_y )
276                 {
277                   best_point = pp;
278                   best_y     = points[pp].y;
279                 }
280             }
281 
282             if ( best_point != old_best_point )
283             {
284               best_first = first;
285               best_last  = last;
286             }
287           }
288           FT_TRACE5(( "  %c  %d", *p, best_y ));
289         }
290 
291         /* now check whether the point belongs to a straight or round   */
292         /* segment; we first need to find in which contour the extremum */
293         /* lies, then inspect its previous and next points              */
294         {
295           FT_Pos  best_x = points[best_point].x;
296           FT_Int  start, end, prev, next;
297           FT_Pos  dist;
298 
299 
300           /* now look for the previous and next points that are not on the */
301           /* same Y coordinate.  Threshold the `closeness'...              */
302           start = end = best_point;
303 
304           do
305           {
306             prev = start - 1;
307             if ( prev < best_first )
308               prev = best_last;
309 
310             dist = FT_ABS( points[prev].y - best_y );
311             /* accept a small distance or a small angle (both values are */
312             /* heuristic; value 20 corresponds to approx. 2.9 degrees)   */
313             if ( dist > 5 )
314               if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist )
315                 break;
316 
317             start = prev;
318 
319           } while ( start != best_point );
320 
321           do
322           {
323             next = end + 1;
324             if ( next > best_last )
325               next = best_first;
326 
327             dist = FT_ABS( points[next].y - best_y );
328             if ( dist > 5 )
329               if ( FT_ABS( points[next].x - best_x ) <= 20 * dist )
330                 break;
331 
332             end = next;
333 
334           } while ( end != best_point );
335 
336           /* now, set the `round' flag depending on the segment's kind */
337           round = FT_BOOL(
338             FT_CURVE_TAG( glyph->outline.tags[start] ) != FT_CURVE_TAG_ON ||
339             FT_CURVE_TAG( glyph->outline.tags[ end ] ) != FT_CURVE_TAG_ON );
340 
341           FT_TRACE5(( " (%s)\n", round ? "round" : "flat" ));
342         }
343 
344         if ( round )
345           rounds[num_rounds++] = best_y;
346         else
347           flats[num_flats++]   = best_y;
348       }
349 
350       if ( num_flats == 0 && num_rounds == 0 )
351       {
352         /*
353          *  we couldn't find a single glyph to compute this blue zone,
354          *  we will simply ignore it then
355          */
356         FT_TRACE5(( "  empty\n" ));
357         continue;
358       }
359 
360       /* we have computed the contents of the `rounds' and `flats' tables, */
361       /* now determine the reference and overshoot position of the blue -- */
362       /* we simply take the median value after a simple sort               */
363       af_sort_pos( num_rounds, rounds );
364       af_sort_pos( num_flats,  flats );
365 
366       blue       = & axis->blues[axis->blue_count];
367       blue_ref   = & blue->ref.org;
368       blue_shoot = & blue->shoot.org;
369 
370       axis->blue_count++;
371 
372       if ( num_flats == 0 )
373       {
374         *blue_ref   =
375         *blue_shoot = rounds[num_rounds / 2];
376       }
377       else if ( num_rounds == 0 )
378       {
379         *blue_ref   =
380         *blue_shoot = flats[num_flats / 2];
381       }
382       else
383       {
384         *blue_ref   = flats[num_flats / 2];
385         *blue_shoot = rounds[num_rounds / 2];
386       }
387 
388       /* there are sometimes problems: if the overshoot position of top     */
389       /* zones is under its reference position, or the opposite for bottom  */
390       /* zones.  We must thus check everything there and correct the errors */
391       if ( *blue_shoot != *blue_ref )
392       {
393         FT_Pos   ref      = *blue_ref;
394         FT_Pos   shoot    = *blue_shoot;
395         FT_Bool  over_ref = FT_BOOL( shoot > ref );
396 
397 
398         if ( AF_LATIN_IS_TOP_BLUE( bb ) ^ over_ref )
399         {
400           *blue_ref   =
401           *blue_shoot = ( shoot + ref ) / 2;
402 
403           FT_TRACE5(( "  [overshoot smaller than reference,"
404                       " taking mean value]\n" ));
405         }
406       }
407 
408       blue->flags = 0;
409       if ( AF_LATIN_IS_TOP_BLUE( bb ) )
410         blue->flags |= AF_LATIN_BLUE_TOP;
411 
412       /*
413        * The following flag is used later to adjust the y and x scales
414        * in order to optimize the pixel grid alignment of the top of small
415        * letters.
416        */
417       if ( AF_LATIN_IS_X_HEIGHT_BLUE( bb ) )
418         blue->flags |= AF_LATIN_BLUE_ADJUSTMENT;
419 
420       FT_TRACE5(( "    -> reference = %ld\n"
421                   "       overshoot = %ld\n",
422                   *blue_ref, *blue_shoot ));
423     }
424 
425     return;
426   }
427 
428 
429   FT_LOCAL_DEF( void )
af_latin2_metrics_check_digits(AF_LatinMetrics metrics,FT_Face face)430   af_latin2_metrics_check_digits( AF_LatinMetrics  metrics,
431                                   FT_Face          face )
432   {
433     FT_UInt   i;
434     FT_Bool   started = 0, same_width = 1;
435     FT_Fixed  advance, old_advance = 0;
436 
437 
438     /* check whether all ASCII digits have the same advance width; */
439     /* digit `0' is 0x30 in all supported charmaps                 */
440     for ( i = 0x30; i <= 0x39; i++ )
441     {
442       FT_UInt  glyph_index;
443 
444 
445       glyph_index = FT_Get_Char_Index( face, i );
446       if ( glyph_index == 0 )
447         continue;
448 
449       if ( FT_Get_Advance( face, glyph_index,
450                            FT_LOAD_NO_SCALE         |
451                            FT_LOAD_NO_HINTING       |
452                            FT_LOAD_IGNORE_TRANSFORM,
453                            &advance ) )
454         continue;
455 
456       if ( started )
457       {
458         if ( advance != old_advance )
459         {
460           same_width = 0;
461           break;
462         }
463       }
464       else
465       {
466         old_advance = advance;
467         started     = 1;
468       }
469     }
470 
471     metrics->root.digits_have_same_width = same_width;
472   }
473 
474 
475   FT_LOCAL_DEF( FT_Error )
af_latin2_metrics_init(AF_LatinMetrics metrics,FT_Face face)476   af_latin2_metrics_init( AF_LatinMetrics  metrics,
477                           FT_Face          face )
478   {
479     FT_Error    error  = FT_Err_Ok;
480     FT_CharMap  oldmap = face->charmap;
481     FT_UInt     ee;
482 
483     static const FT_Encoding  latin_encodings[] =
484     {
485       FT_ENCODING_UNICODE,
486       FT_ENCODING_APPLE_ROMAN,
487       FT_ENCODING_ADOBE_STANDARD,
488       FT_ENCODING_ADOBE_LATIN_1,
489       FT_ENCODING_NONE  /* end of list */
490     };
491 
492 
493     metrics->units_per_em = face->units_per_EM;
494 
495     /* do we have a latin charmap in there? */
496     for ( ee = 0; latin_encodings[ee] != FT_ENCODING_NONE; ee++ )
497     {
498       error = FT_Select_Charmap( face, latin_encodings[ee] );
499       if ( !error )
500         break;
501     }
502 
503     if ( !error )
504     {
505       af_latin2_metrics_init_widths( metrics, face );
506       af_latin2_metrics_init_blues( metrics, face );
507       af_latin2_metrics_check_digits( metrics, face );
508     }
509 
510     FT_Set_Charmap( face, oldmap );
511     return FT_Err_Ok;
512   }
513 
514 
515   static void
af_latin2_metrics_scale_dim(AF_LatinMetrics metrics,AF_Scaler scaler,AF_Dimension dim)516   af_latin2_metrics_scale_dim( AF_LatinMetrics  metrics,
517                                AF_Scaler        scaler,
518                                AF_Dimension     dim )
519   {
520     FT_Fixed      scale;
521     FT_Pos        delta;
522     AF_LatinAxis  axis;
523     FT_UInt       nn;
524 
525 
526     if ( dim == AF_DIMENSION_HORZ )
527     {
528       scale = scaler->x_scale;
529       delta = scaler->x_delta;
530     }
531     else
532     {
533       scale = scaler->y_scale;
534       delta = scaler->y_delta;
535     }
536 
537     axis = &metrics->axis[dim];
538 
539     if ( axis->org_scale == scale && axis->org_delta == delta )
540       return;
541 
542     axis->org_scale = scale;
543     axis->org_delta = delta;
544 
545     /*
546      * correct Y scale to optimize the alignment of the top of small
547      * letters to the pixel grid
548      */
549     if ( dim == AF_DIMENSION_VERT )
550     {
551       AF_LatinAxis  vaxis = &metrics->axis[AF_DIMENSION_VERT];
552       AF_LatinBlue  blue = NULL;
553 
554 
555       for ( nn = 0; nn < vaxis->blue_count; nn++ )
556       {
557         if ( vaxis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT )
558         {
559           blue = &vaxis->blues[nn];
560           break;
561         }
562       }
563 
564       if ( blue )
565       {
566         FT_Pos   scaled;
567         FT_Pos   threshold;
568         FT_Pos   fitted;
569         FT_UInt  limit;
570         FT_UInt  ppem;
571 
572 
573         scaled    = FT_MulFix( blue->shoot.org, scaler->y_scale );
574         ppem      = metrics->root.scaler.face->size->metrics.x_ppem;
575         limit     = metrics->root.globals->increase_x_height;
576         threshold = 40;
577 
578         /* if the `increase-x-height' property is active, */
579         /* we round up much more often                    */
580         if ( limit                                 &&
581              ppem <= limit                         &&
582              ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN )
583           threshold = 52;
584 
585         fitted = ( scaled + threshold ) & ~63;
586 
587 #if 1
588         if ( scaled != fitted )
589         {
590           scale = FT_MulDiv( scale, fitted, scaled );
591           FT_TRACE5(( "== scaled x-top = %.2g"
592                       "  fitted = %.2g, scaling = %.4g\n",
593                       scaled / 64.0, fitted / 64.0,
594                       ( fitted * 1.0 ) / scaled ));
595         }
596 #endif
597       }
598     }
599 
600     axis->scale = scale;
601     axis->delta = delta;
602 
603     if ( dim == AF_DIMENSION_HORZ )
604     {
605       metrics->root.scaler.x_scale = scale;
606       metrics->root.scaler.x_delta = delta;
607     }
608     else
609     {
610       metrics->root.scaler.y_scale = scale;
611       metrics->root.scaler.y_delta = delta;
612     }
613 
614     /* scale the standard widths */
615     for ( nn = 0; nn < axis->width_count; nn++ )
616     {
617       AF_Width  width = axis->widths + nn;
618 
619 
620       width->cur = FT_MulFix( width->org, scale );
621       width->fit = width->cur;
622     }
623 
624     /* an extra-light axis corresponds to a standard width that is */
625     /* smaller than 5/8 pixels                                     */
626     axis->extra_light =
627       (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 );
628 
629     if ( dim == AF_DIMENSION_VERT )
630     {
631       /* scale the blue zones */
632       for ( nn = 0; nn < axis->blue_count; nn++ )
633       {
634         AF_LatinBlue  blue = &axis->blues[nn];
635         FT_Pos        dist;
636 
637 
638         blue->ref.cur   = FT_MulFix( blue->ref.org, scale ) + delta;
639         blue->ref.fit   = blue->ref.cur;
640         blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
641         blue->shoot.fit = blue->shoot.cur;
642         blue->flags    &= ~AF_LATIN_BLUE_ACTIVE;
643 
644         /* a blue zone is only active if it is less than 3/4 pixels tall */
645         dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
646         if ( dist <= 48 && dist >= -48 )
647         {
648           FT_Pos  delta1, delta2;
649 
650           delta1 = blue->shoot.org - blue->ref.org;
651           delta2 = delta1;
652           if ( delta1 < 0 )
653             delta2 = -delta2;
654 
655           delta2 = FT_MulFix( delta2, scale );
656 
657           if ( delta2 < 32 )
658             delta2 = 0;
659           else if ( delta2 < 64 )
660             delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
661           else
662             delta2 = FT_PIX_ROUND( delta2 );
663 
664           if ( delta1 < 0 )
665             delta2 = -delta2;
666 
667           blue->ref.fit   = FT_PIX_ROUND( blue->ref.cur );
668           blue->shoot.fit = blue->ref.fit + delta2;
669 
670           FT_TRACE5(( ">> activating blue zone %d:"
671                       "  ref.cur=%.2g ref.fit=%.2g"
672                       "  shoot.cur=%.2g shoot.fit=%.2g\n",
673                       nn, blue->ref.cur / 64.0, blue->ref.fit / 64.0,
674                       blue->shoot.cur / 64.0, blue->shoot.fit / 64.0 ));
675 
676           blue->flags |= AF_LATIN_BLUE_ACTIVE;
677         }
678       }
679     }
680   }
681 
682 
683   FT_LOCAL_DEF( void )
af_latin2_metrics_scale(AF_LatinMetrics metrics,AF_Scaler scaler)684   af_latin2_metrics_scale( AF_LatinMetrics  metrics,
685                            AF_Scaler        scaler )
686   {
687     metrics->root.scaler.render_mode = scaler->render_mode;
688     metrics->root.scaler.face        = scaler->face;
689     metrics->root.scaler.flags       = scaler->flags;
690 
691     af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
692     af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
693   }
694 
695 
696   /*************************************************************************/
697   /*************************************************************************/
698   /*****                                                               *****/
699   /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
700   /*****                                                               *****/
701   /*************************************************************************/
702   /*************************************************************************/
703 
704 #define  SORT_SEGMENTS
705 
706   FT_LOCAL_DEF( FT_Error )
af_latin2_hints_compute_segments(AF_GlyphHints hints,AF_Dimension dim)707   af_latin2_hints_compute_segments( AF_GlyphHints  hints,
708                                     AF_Dimension   dim )
709   {
710     AF_AxisHints  axis          = &hints->axis[dim];
711     FT_Memory     memory        = hints->memory;
712     FT_Error      error         = FT_Err_Ok;
713     AF_Segment    segment       = NULL;
714     AF_SegmentRec seg0;
715     AF_Point*     contour       = hints->contours;
716     AF_Point*     contour_limit = contour + hints->num_contours;
717     AF_Direction  major_dir, segment_dir;
718 
719 
720     FT_ZERO( &seg0 );
721     seg0.score = 32000;
722     seg0.flags = AF_EDGE_NORMAL;
723 
724     major_dir   = (AF_Direction)FT_ABS( axis->major_dir );
725     segment_dir = major_dir;
726 
727     axis->num_segments = 0;
728 
729     /* set up (u,v) in each point */
730     if ( dim == AF_DIMENSION_HORZ )
731     {
732       AF_Point  point = hints->points;
733       AF_Point  limit = point + hints->num_points;
734 
735 
736       for ( ; point < limit; point++ )
737       {
738         point->u = point->fx;
739         point->v = point->fy;
740       }
741     }
742     else
743     {
744       AF_Point  point = hints->points;
745       AF_Point  limit = point + hints->num_points;
746 
747 
748       for ( ; point < limit; point++ )
749       {
750         point->u = point->fy;
751         point->v = point->fx;
752       }
753     }
754 
755     /* do each contour separately */
756     for ( ; contour < contour_limit; contour++ )
757     {
758       AF_Point  point   =  contour[0];
759       AF_Point  start   =  point;
760       AF_Point  last    =  point->prev;
761 
762 
763       if ( point == last )  /* skip singletons -- just in case */
764         continue;
765 
766       /* already on an edge ?, backtrack to find its start */
767       if ( FT_ABS( point->in_dir ) == major_dir )
768       {
769         point = point->prev;
770 
771         while ( point->in_dir == start->in_dir )
772           point = point->prev;
773       }
774       else  /* otherwise, find first segment start, if any */
775       {
776         while ( FT_ABS( point->out_dir ) != major_dir )
777         {
778           point = point->next;
779 
780           if ( point == start )
781             goto NextContour;
782         }
783       }
784 
785       start = point;
786 
787       for  (;;)
788       {
789         AF_Point  first;
790         FT_Pos    min_u, min_v, max_u, max_v;
791 
792         /* we're at the start of a new segment */
793         FT_ASSERT( FT_ABS( point->out_dir ) == major_dir &&
794                            point->in_dir != point->out_dir );
795         first = point;
796 
797         min_u = max_u = point->u;
798         min_v = max_v = point->v;
799 
800         point = point->next;
801 
802         while ( point->out_dir == first->out_dir )
803         {
804           point = point->next;
805 
806           if ( point->u < min_u )
807             min_u = point->u;
808 
809           if ( point->u > max_u )
810             max_u = point->u;
811         }
812 
813         if ( point->v < min_v )
814           min_v = point->v;
815 
816         if ( point->v > max_v )
817           max_v = point->v;
818 
819         /* record new segment */
820         error = af_axis_hints_new_segment( axis, memory, &segment );
821         if ( error )
822           goto Exit;
823 
824         segment[0]         = seg0;
825         segment->dir       = first->out_dir;
826         segment->first     = first;
827         segment->last      = point;
828         segment->pos       = (FT_Short)( ( min_u + max_u ) >> 1 );
829         segment->min_coord = (FT_Short) min_v;
830         segment->max_coord = (FT_Short) max_v;
831         segment->height    = (FT_Short)( max_v - min_v );
832 
833         /* a segment is round if it doesn't have successive */
834         /* on-curve points.                                 */
835         {
836           AF_Point  pt   = first;
837           AF_Point  last = point;
838           FT_UInt   f0   = pt->flags & AF_FLAG_CONTROL;
839           FT_UInt   f1;
840 
841 
842           segment->flags &= ~AF_EDGE_ROUND;
843 
844           for ( ; pt != last; f0 = f1 )
845           {
846             pt = pt->next;
847             f1 = pt->flags & AF_FLAG_CONTROL;
848 
849             if ( !f0 && !f1 )
850               break;
851 
852             if ( pt == last )
853               segment->flags |= AF_EDGE_ROUND;
854           }
855         }
856 
857        /* this can happen in the case of a degenerate contour
858         * e.g. a 2-point vertical contour
859         */
860         if ( point == start )
861           break;
862 
863         /* jump to the start of the next segment, if any */
864         while ( FT_ABS( point->out_dir ) != major_dir )
865         {
866           point = point->next;
867 
868           if ( point == start )
869             goto NextContour;
870         }
871       }
872 
873     NextContour:
874       ;
875     } /* contours */
876 
877     /* now slightly increase the height of segments when this makes */
878     /* sense -- this is used to better detect and ignore serifs     */
879     {
880       AF_Segment  segments     = axis->segments;
881       AF_Segment  segments_end = segments + axis->num_segments;
882 
883 
884       for ( segment = segments; segment < segments_end; segment++ )
885       {
886         AF_Point  first   = segment->first;
887         AF_Point  last    = segment->last;
888         AF_Point  p;
889         FT_Pos    first_v = first->v;
890         FT_Pos    last_v  = last->v;
891 
892 
893         if ( first_v < last_v )
894         {
895           p = first->prev;
896           if ( p->v < first_v )
897             segment->height = (FT_Short)( segment->height +
898                                           ( ( first_v - p->v ) >> 1 ) );
899 
900           p = last->next;
901           if ( p->v > last_v )
902             segment->height = (FT_Short)( segment->height +
903                                           ( ( p->v - last_v ) >> 1 ) );
904         }
905         else
906         {
907           p = first->prev;
908           if ( p->v > first_v )
909             segment->height = (FT_Short)( segment->height +
910                                           ( ( p->v - first_v ) >> 1 ) );
911 
912           p = last->next;
913           if ( p->v < last_v )
914             segment->height = (FT_Short)( segment->height +
915                                           ( ( last_v - p->v ) >> 1 ) );
916         }
917       }
918     }
919 
920 #ifdef AF_SORT_SEGMENTS
921    /* place all segments with a negative direction to the start
922     * of the array, used to speed up segment linking later...
923     */
924     {
925       AF_Segment  segments = axis->segments;
926       FT_UInt     count    = axis->num_segments;
927       FT_UInt     ii, jj;
928 
929       for ( ii = 0; ii < count; ii++ )
930       {
931         if ( segments[ii].dir > 0 )
932         {
933           for ( jj = ii + 1; jj < count; jj++ )
934           {
935             if ( segments[jj].dir < 0 )
936             {
937               AF_SegmentRec  tmp;
938 
939 
940               tmp          = segments[ii];
941               segments[ii] = segments[jj];
942               segments[jj] = tmp;
943 
944               break;
945             }
946           }
947 
948           if ( jj == count )
949             break;
950         }
951       }
952       axis->mid_segments = ii;
953     }
954 #endif
955 
956   Exit:
957     return error;
958   }
959 
960 
961   FT_LOCAL_DEF( void )
af_latin2_hints_link_segments(AF_GlyphHints hints,AF_Dimension dim)962   af_latin2_hints_link_segments( AF_GlyphHints  hints,
963                                  AF_Dimension   dim )
964   {
965     AF_AxisHints  axis          = &hints->axis[dim];
966     AF_Segment    segments      = axis->segments;
967     AF_Segment    segment_limit = segments + axis->num_segments;
968 #ifdef AF_SORT_SEGMENTS
969     AF_Segment    segment_mid   = segments + axis->mid_segments;
970 #endif
971     FT_Pos        len_threshold, len_score;
972     AF_Segment    seg1, seg2;
973 
974 
975     len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
976     if ( len_threshold == 0 )
977       len_threshold = 1;
978 
979     len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 );
980 
981 #ifdef AF_SORT_SEGMENTS
982     for ( seg1 = segments; seg1 < segment_mid; seg1++ )
983     {
984       if ( seg1->dir != axis->major_dir )
985         continue;
986 
987       for ( seg2 = segment_mid; seg2 < segment_limit; seg2++ )
988 #else
989     /* now compare each segment to the others */
990     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
991     {
992       if ( seg1->dir != axis->major_dir )
993         continue;
994 
995       for ( seg2 = segments; seg2 < segment_limit; seg2++ )
996         if ( seg1->dir + seg2->dir == 0 && seg2->pos > seg1->pos )
997 #endif
998         {
999           FT_Pos  pos1 = seg1->pos;
1000           FT_Pos  pos2 = seg2->pos;
1001           FT_Pos  dist = pos2 - pos1;
1002 
1003 
1004           if ( dist < 0 )
1005             continue;
1006 
1007           {
1008             FT_Pos  min = seg1->min_coord;
1009             FT_Pos  max = seg1->max_coord;
1010             FT_Pos  len, score;
1011 
1012 
1013             if ( min < seg2->min_coord )
1014               min = seg2->min_coord;
1015 
1016             if ( max > seg2->max_coord )
1017               max = seg2->max_coord;
1018 
1019             len = max - min;
1020             if ( len >= len_threshold )
1021             {
1022               score = dist + len_score / len;
1023               if ( score < seg1->score )
1024               {
1025                 seg1->score = score;
1026                 seg1->link  = seg2;
1027               }
1028 
1029               if ( score < seg2->score )
1030               {
1031                 seg2->score = score;
1032                 seg2->link  = seg1;
1033               }
1034             }
1035           }
1036         }
1037     }
1038 #if 0
1039     }
1040 #endif
1041 
1042     /* now, compute the `serif' segments */
1043     for ( seg1 = segments; seg1 < segment_limit; seg1++ )
1044     {
1045       seg2 = seg1->link;
1046 
1047       if ( seg2 )
1048       {
1049         if ( seg2->link != seg1 )
1050         {
1051           seg1->link  = NULL;
1052           seg1->serif = seg2->link;
1053         }
1054       }
1055     }
1056   }
1057 
1058 
1059   FT_LOCAL_DEF( FT_Error )
af_latin2_hints_compute_edges(AF_GlyphHints hints,AF_Dimension dim)1060   af_latin2_hints_compute_edges( AF_GlyphHints  hints,
1061                                  AF_Dimension   dim )
1062   {
1063     AF_AxisHints  axis   = &hints->axis[dim];
1064     FT_Error      error  = FT_Err_Ok;
1065     FT_Memory     memory = hints->memory;
1066     AF_LatinAxis  laxis  = &((AF_LatinMetrics)hints->metrics)->axis[dim];
1067 
1068     AF_Segment    segments      = axis->segments;
1069     AF_Segment    segment_limit = segments + axis->num_segments;
1070     AF_Segment    seg;
1071 
1072     AF_Direction  up_dir;
1073     FT_Fixed      scale;
1074     FT_Pos        edge_distance_threshold;
1075     FT_Pos        segment_length_threshold;
1076 
1077 
1078     axis->num_edges = 0;
1079 
1080     scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
1081                                          : hints->y_scale;
1082 
1083     up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP
1084                                           : AF_DIR_RIGHT;
1085 
1086     /*
1087      *  We want to ignore very small (mostly serif) segments, we do that
1088      *  by ignoring those that whose length is less than a given fraction
1089      *  of the standard width. If there is no standard width, we ignore
1090      *  those that are less than a given size in pixels
1091      *
1092      *  also, unlink serif segments that are linked to segments farther
1093      *  than 50% of the standard width
1094      */
1095     if ( dim == AF_DIMENSION_HORZ )
1096     {
1097       if ( laxis->width_count > 0 )
1098         segment_length_threshold = ( laxis->standard_width * 10 ) >> 4;
1099       else
1100         segment_length_threshold = FT_DivFix( 64, hints->y_scale );
1101     }
1102     else
1103       segment_length_threshold = 0;
1104 
1105     /*********************************************************************/
1106     /*                                                                   */
1107     /* We will begin by generating a sorted table of edges for the       */
1108     /* current direction.  To do so, we simply scan each segment and try */
1109     /* to find an edge in our table that corresponds to its position.    */
1110     /*                                                                   */
1111     /* If no edge is found, we create and insert a new edge in the       */
1112     /* sorted table.  Otherwise, we simply add the segment to the edge's */
1113     /* list which will be processed in the second step to compute the    */
1114     /* edge's properties.                                                */
1115     /*                                                                   */
1116     /* Note that the edges table is sorted along the segment/edge        */
1117     /* position.                                                         */
1118     /*                                                                   */
1119     /*********************************************************************/
1120 
1121     edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
1122                                          scale );
1123     if ( edge_distance_threshold > 64 / 4 )
1124       edge_distance_threshold = 64 / 4;
1125 
1126     edge_distance_threshold = FT_DivFix( edge_distance_threshold,
1127                                          scale );
1128 
1129     for ( seg = segments; seg < segment_limit; seg++ )
1130     {
1131       AF_Edge  found = NULL;
1132       FT_Int   ee;
1133 
1134 
1135       if ( seg->height < segment_length_threshold )
1136         continue;
1137 
1138       /* A special case for serif edges: If they are smaller than */
1139       /* 1.5 pixels we ignore them.                               */
1140       if ( seg->serif )
1141       {
1142         FT_Pos  dist = seg->serif->pos - seg->pos;
1143 
1144 
1145         if ( dist < 0 )
1146           dist = -dist;
1147 
1148         if ( dist >= laxis->standard_width >> 1 )
1149         {
1150           /* unlink this serif, it is too distant from its reference stem */
1151           seg->serif = NULL;
1152         }
1153         else if ( 2*seg->height < 3 * segment_length_threshold )
1154           continue;
1155       }
1156 
1157       /* look for an edge corresponding to the segment */
1158       for ( ee = 0; ee < axis->num_edges; ee++ )
1159       {
1160         AF_Edge  edge = axis->edges + ee;
1161         FT_Pos   dist;
1162 
1163 
1164         dist = seg->pos - edge->fpos;
1165         if ( dist < 0 )
1166           dist = -dist;
1167 
1168         if ( dist < edge_distance_threshold && edge->dir == seg->dir )
1169         {
1170           found = edge;
1171           break;
1172         }
1173       }
1174 
1175       if ( !found )
1176       {
1177         AF_Edge   edge;
1178 
1179 
1180         /* insert a new edge in the list and */
1181         /* sort according to the position    */
1182         error = af_axis_hints_new_edge( axis, seg->pos, seg->dir,
1183                                         memory, &edge );
1184         if ( error )
1185           goto Exit;
1186 
1187         /* add the segment to the new edge's list */
1188         FT_ZERO( edge );
1189 
1190         edge->first    = seg;
1191         edge->last     = seg;
1192         edge->dir      = seg->dir;
1193         edge->fpos     = seg->pos;
1194         edge->opos     = FT_MulFix( seg->pos, scale );
1195         edge->pos      = edge->opos;
1196         seg->edge_next = seg;
1197       }
1198       else
1199       {
1200         /* if an edge was found, simply add the segment to the edge's */
1201         /* list                                                       */
1202         seg->edge_next         = found->first;
1203         found->last->edge_next = seg;
1204         found->last            = seg;
1205       }
1206     }
1207 
1208 
1209     /*********************************************************************/
1210     /*                                                                   */
1211     /* Good, we will now compute each edge's properties according to     */
1212     /* segments found on its position.  Basically, these are:            */
1213     /*                                                                   */
1214     /*  - edge's main direction                                          */
1215     /*  - stem edge, serif edge or both (which defaults to stem then)    */
1216     /*  - rounded edge, straight or both (which defaults to straight)    */
1217     /*  - link for edge                                                  */
1218     /*                                                                   */
1219     /*********************************************************************/
1220 
1221     /* first of all, set the `edge' field in each segment -- this is */
1222     /* required in order to compute edge links                       */
1223 
1224     /*
1225      * Note that removing this loop and setting the `edge' field of each
1226      * segment directly in the code above slows down execution speed for
1227      * some reasons on platforms like the Sun.
1228      */
1229     {
1230       AF_Edge  edges      = axis->edges;
1231       AF_Edge  edge_limit = edges + axis->num_edges;
1232       AF_Edge  edge;
1233 
1234 
1235       for ( edge = edges; edge < edge_limit; edge++ )
1236       {
1237         seg = edge->first;
1238         if ( seg )
1239           do
1240           {
1241             seg->edge = edge;
1242             seg       = seg->edge_next;
1243 
1244           } while ( seg != edge->first );
1245       }
1246 
1247       /* now, compute each edge properties */
1248       for ( edge = edges; edge < edge_limit; edge++ )
1249       {
1250         FT_Int  is_round    = 0;  /* does it contain round segments?    */
1251         FT_Int  is_straight = 0;  /* does it contain straight segments? */
1252 #if 0
1253         FT_Pos  ups         = 0;  /* number of upwards segments         */
1254         FT_Pos  downs       = 0;  /* number of downwards segments       */
1255 #endif
1256 
1257 
1258         seg = edge->first;
1259 
1260         do
1261         {
1262           FT_Bool  is_serif;
1263 
1264 
1265           /* check for roundness of segment */
1266           if ( seg->flags & AF_EDGE_ROUND )
1267             is_round++;
1268           else
1269             is_straight++;
1270 
1271 #if 0
1272           /* check for segment direction */
1273           if ( seg->dir == up_dir )
1274             ups   += seg->max_coord-seg->min_coord;
1275           else
1276             downs += seg->max_coord-seg->min_coord;
1277 #endif
1278 
1279           /* check for links -- if seg->serif is set, then seg->link must */
1280           /* be ignored                                                   */
1281           is_serif = (FT_Bool)( seg->serif               &&
1282                                 seg->serif->edge         &&
1283                                 seg->serif->edge != edge );
1284 
1285           if ( ( seg->link && seg->link->edge != NULL ) || is_serif )
1286           {
1287             AF_Edge     edge2;
1288             AF_Segment  seg2;
1289 
1290 
1291             edge2 = edge->link;
1292             seg2  = seg->link;
1293 
1294             if ( is_serif )
1295             {
1296               seg2  = seg->serif;
1297               edge2 = edge->serif;
1298             }
1299 
1300             if ( edge2 )
1301             {
1302               FT_Pos  edge_delta;
1303               FT_Pos  seg_delta;
1304 
1305 
1306               edge_delta = edge->fpos - edge2->fpos;
1307               if ( edge_delta < 0 )
1308                 edge_delta = -edge_delta;
1309 
1310               seg_delta = seg->pos - seg2->pos;
1311               if ( seg_delta < 0 )
1312                 seg_delta = -seg_delta;
1313 
1314               if ( seg_delta < edge_delta )
1315                 edge2 = seg2->edge;
1316             }
1317             else
1318               edge2 = seg2->edge;
1319 
1320             if ( is_serif )
1321             {
1322               edge->serif   = edge2;
1323               edge2->flags |= AF_EDGE_SERIF;
1324             }
1325             else
1326               edge->link  = edge2;
1327           }
1328 
1329           seg = seg->edge_next;
1330 
1331         } while ( seg != edge->first );
1332 
1333         /* set the round/straight flags */
1334         edge->flags = AF_EDGE_NORMAL;
1335 
1336         if ( is_round > 0 && is_round >= is_straight )
1337           edge->flags |= AF_EDGE_ROUND;
1338 
1339 #if 0
1340         /* set the edge's main direction */
1341         edge->dir = AF_DIR_NONE;
1342 
1343         if ( ups > downs )
1344           edge->dir = (FT_Char)up_dir;
1345 
1346         else if ( ups < downs )
1347           edge->dir = (FT_Char)-up_dir;
1348 
1349         else if ( ups == downs )
1350           edge->dir = 0;  /* both up and down! */
1351 #endif
1352 
1353         /* gets rid of serifs if link is set                */
1354         /* XXX: This gets rid of many unpleasant artefacts! */
1355         /*      Example: the `c' in cour.pfa at size 13     */
1356 
1357         if ( edge->serif && edge->link )
1358           edge->serif = NULL;
1359       }
1360     }
1361 
1362   Exit:
1363     return error;
1364   }
1365 
1366 
1367   FT_LOCAL_DEF( FT_Error )
af_latin2_hints_detect_features(AF_GlyphHints hints,AF_Dimension dim)1368   af_latin2_hints_detect_features( AF_GlyphHints  hints,
1369                                    AF_Dimension   dim )
1370   {
1371     FT_Error  error;
1372 
1373 
1374     error = af_latin2_hints_compute_segments( hints, dim );
1375     if ( !error )
1376     {
1377       af_latin2_hints_link_segments( hints, dim );
1378 
1379       error = af_latin2_hints_compute_edges( hints, dim );
1380     }
1381     return error;
1382   }
1383 
1384 
1385   static void
af_latin2_hints_compute_blue_edges(AF_GlyphHints hints,AF_LatinMetrics metrics)1386   af_latin2_hints_compute_blue_edges( AF_GlyphHints    hints,
1387                                       AF_LatinMetrics  metrics )
1388   {
1389     AF_AxisHints  axis       = &hints->axis[AF_DIMENSION_VERT];
1390     AF_Edge       edge       = axis->edges;
1391     AF_Edge       edge_limit = edge + axis->num_edges;
1392     AF_LatinAxis  latin      = &metrics->axis[AF_DIMENSION_VERT];
1393     FT_Fixed      scale      = latin->scale;
1394     FT_Pos        best_dist0;  /* initial threshold */
1395 
1396 
1397     /* compute the initial threshold as a fraction of the EM size */
1398     best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
1399 
1400     if ( best_dist0 > 64 / 2 )
1401       best_dist0 = 64 / 2;
1402 
1403     /* compute which blue zones are active, i.e. have their scaled */
1404     /* size < 3/4 pixels                                           */
1405 
1406     /* for each horizontal edge search the blue zone which is closest */
1407     for ( ; edge < edge_limit; edge++ )
1408     {
1409       FT_Int    bb;
1410       AF_Width  best_blue = NULL;
1411       FT_Pos    best_dist = best_dist0;
1412 
1413       for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
1414       {
1415         AF_LatinBlue  blue = latin->blues + bb;
1416         FT_Bool       is_top_blue, is_major_dir;
1417 
1418 
1419         /* skip inactive blue zones (i.e., those that are too small) */
1420         if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) )
1421           continue;
1422 
1423         /* if it is a top zone, check for right edges -- if it is a bottom */
1424         /* zone, check for left edges                                      */
1425         /*                                                                 */
1426         /* of course, that's for TrueType                                  */
1427         is_top_blue  = (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 );
1428         is_major_dir = FT_BOOL( edge->dir == axis->major_dir );
1429 
1430         /* if it is a top zone, the edge must be against the major    */
1431         /* direction; if it is a bottom zone, it must be in the major */
1432         /* direction                                                  */
1433         if ( is_top_blue ^ is_major_dir )
1434         {
1435           FT_Pos     dist;
1436           AF_Width   compare;
1437 
1438 
1439           /* if it's a rounded edge, compare it to the overshoot position */
1440           /* if it's a flat edge, compare it to the reference position    */
1441           if ( edge->flags & AF_EDGE_ROUND )
1442             compare = &blue->shoot;
1443           else
1444             compare = &blue->ref;
1445 
1446           dist = edge->fpos - compare->org;
1447           if ( dist < 0 )
1448             dist = -dist;
1449 
1450           dist = FT_MulFix( dist, scale );
1451           if ( dist < best_dist )
1452           {
1453             best_dist = dist;
1454             best_blue = compare;
1455           }
1456 
1457 #if 0
1458           /* now, compare it to the overshoot position if the edge is     */
1459           /* rounded, and if the edge is over the reference position of a */
1460           /* top zone, or under the reference position of a bottom zone   */
1461           if ( edge->flags & AF_EDGE_ROUND && dist != 0 )
1462           {
1463             FT_Bool  is_under_ref = FT_BOOL( edge->fpos < blue->ref.org );
1464 
1465 
1466             if ( is_top_blue ^ is_under_ref )
1467             {
1468               blue = latin->blues + bb;
1469               dist = edge->fpos - blue->shoot.org;
1470               if ( dist < 0 )
1471                 dist = -dist;
1472 
1473               dist = FT_MulFix( dist, scale );
1474               if ( dist < best_dist )
1475               {
1476                 best_dist = dist;
1477                 best_blue = & blue->shoot;
1478               }
1479             }
1480           }
1481 #endif
1482         }
1483       }
1484 
1485       if ( best_blue )
1486         edge->blue_edge = best_blue;
1487     }
1488   }
1489 
1490 
1491   static FT_Error
af_latin2_hints_init(AF_GlyphHints hints,AF_LatinMetrics metrics)1492   af_latin2_hints_init( AF_GlyphHints    hints,
1493                         AF_LatinMetrics  metrics )
1494   {
1495     FT_Render_Mode  mode;
1496     FT_UInt32       scaler_flags, other_flags;
1497     FT_Face         face = metrics->root.scaler.face;
1498 
1499 
1500     af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics );
1501 
1502     /*
1503      *  correct x_scale and y_scale if needed, since they may have
1504      *  been modified `af_latin2_metrics_scale_dim' above
1505      */
1506     hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
1507     hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
1508     hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
1509     hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
1510 
1511     /* compute flags depending on render mode, etc. */
1512     mode = metrics->root.scaler.render_mode;
1513 
1514 #if 0 /* #ifdef AF_CONFIG_OPTION_USE_WARPER */
1515     if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
1516       metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
1517 #endif
1518 
1519     scaler_flags = hints->scaler_flags;
1520     other_flags  = 0;
1521 
1522     /*
1523      *  We snap the width of vertical stems for the monochrome and
1524      *  horizontal LCD rendering targets only.
1525      */
1526     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
1527       other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
1528 
1529     /*
1530      *  We snap the width of horizontal stems for the monochrome and
1531      *  vertical LCD rendering targets only.
1532      */
1533     if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
1534       other_flags |= AF_LATIN_HINTS_VERT_SNAP;
1535 
1536     /*
1537      *  We adjust stems to full pixels only if we don't use the `light' mode.
1538      */
1539     if ( mode != FT_RENDER_MODE_LIGHT )
1540       other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
1541 
1542     if ( mode == FT_RENDER_MODE_MONO )
1543       other_flags |= AF_LATIN_HINTS_MONO;
1544 
1545     /*
1546      *  In `light' hinting mode we disable horizontal hinting completely.
1547      *  We also do it if the face is italic.
1548      */
1549     if ( mode == FT_RENDER_MODE_LIGHT                      ||
1550          ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 )
1551       scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL;
1552 
1553 #ifdef AF_CONFIG_OPTION_USE_WARPER
1554     /* get (global) warper flag */
1555     if ( !metrics->root.globals->module->warping )
1556       scaler_flags |= AF_SCALER_FLAG_NO_WARPER;
1557 #endif
1558 
1559     hints->scaler_flags = scaler_flags;
1560     hints->other_flags  = other_flags;
1561 
1562     return 0;
1563   }
1564 
1565 
1566   /*************************************************************************/
1567   /*************************************************************************/
1568   /*****                                                               *****/
1569   /*****        L A T I N   G L Y P H   G R I D - F I T T I N G        *****/
1570   /*****                                                               *****/
1571   /*************************************************************************/
1572   /*************************************************************************/
1573 
1574   /* snap a given width in scaled coordinates to one of the */
1575   /* current standard widths                                */
1576 
1577   static FT_Pos
af_latin2_snap_width(AF_Width widths,FT_UInt count,FT_Pos width)1578   af_latin2_snap_width( AF_Width  widths,
1579                         FT_UInt   count,
1580                         FT_Pos    width )
1581   {
1582     FT_UInt  n;
1583     FT_Pos   best      = 64 + 32 + 2;
1584     FT_Pos   reference = width;
1585     FT_Pos   scaled;
1586 
1587 
1588     for ( n = 0; n < count; n++ )
1589     {
1590       FT_Pos  w;
1591       FT_Pos  dist;
1592 
1593 
1594       w = widths[n].cur;
1595       dist = width - w;
1596       if ( dist < 0 )
1597         dist = -dist;
1598       if ( dist < best )
1599       {
1600         best      = dist;
1601         reference = w;
1602       }
1603     }
1604 
1605     scaled = FT_PIX_ROUND( reference );
1606 
1607     if ( width >= reference )
1608     {
1609       if ( width < scaled + 48 )
1610         width = reference;
1611     }
1612     else
1613     {
1614       if ( width > scaled - 48 )
1615         width = reference;
1616     }
1617 
1618     return width;
1619   }
1620 
1621 
1622   /* compute the snapped width of a given stem */
1623 
1624   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)1625   af_latin2_compute_stem_width( AF_GlyphHints  hints,
1626                                 AF_Dimension   dim,
1627                                 FT_Pos         width,
1628                                 FT_UInt        base_flags,
1629                                 FT_UInt        stem_flags )
1630   {
1631     AF_LatinMetrics  metrics  = (AF_LatinMetrics) hints->metrics;
1632     AF_LatinAxis     axis     = & metrics->axis[dim];
1633     FT_Pos           dist     = width;
1634     FT_Int           sign     = 0;
1635     FT_Int           vertical = ( dim == AF_DIMENSION_VERT );
1636 
1637     FT_UNUSED( base_flags );
1638 
1639 
1640     if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ||
1641           axis->extra_light                      )
1642       return width;
1643 
1644     if ( dist < 0 )
1645     {
1646       dist = -width;
1647       sign = 1;
1648     }
1649 
1650     if ( (  vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
1651          ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
1652     {
1653       /* smooth hinting process: very lightly quantize the stem width */
1654 
1655       /* leave the widths of serifs alone */
1656 
1657       if ( ( stem_flags & AF_EDGE_SERIF ) && vertical && ( dist < 3 * 64 ) )
1658         goto Done_Width;
1659 
1660 #if 0
1661       else if ( ( base_flags & AF_EDGE_ROUND ) )
1662       {
1663         if ( dist < 80 )
1664           dist = 64;
1665       }
1666       else if ( dist < 56 )
1667         dist = 56;
1668 #endif
1669       if ( axis->width_count > 0 )
1670       {
1671         FT_Pos  delta;
1672 
1673 
1674         /* compare to standard width */
1675         if ( axis->width_count > 0 )
1676         {
1677           delta = dist - axis->widths[0].cur;
1678 
1679           if ( delta < 0 )
1680             delta = -delta;
1681 
1682           if ( delta < 40 )
1683           {
1684             dist = axis->widths[0].cur;
1685             if ( dist < 48 )
1686               dist = 48;
1687 
1688             goto Done_Width;
1689           }
1690         }
1691 
1692         if ( dist < 3 * 64 )
1693         {
1694           delta  = dist & 63;
1695           dist  &= -64;
1696 
1697           if ( delta < 10 )
1698             dist += delta;
1699 
1700           else if ( delta < 32 )
1701             dist += 10;
1702 
1703           else if ( delta < 54 )
1704             dist += 54;
1705 
1706           else
1707             dist += delta;
1708         }
1709         else
1710           dist = ( dist + 32 ) & ~63;
1711       }
1712     }
1713     else
1714     {
1715       /* strong hinting process: snap the stem width to integer pixels */
1716       FT_Pos  org_dist = dist;
1717 
1718 
1719       dist = af_latin2_snap_width( axis->widths, axis->width_count, dist );
1720 
1721       if ( vertical )
1722       {
1723         /* in the case of vertical hinting, always round */
1724         /* the stem heights to integer pixels            */
1725 
1726         if ( dist >= 64 )
1727           dist = ( dist + 16 ) & ~63;
1728         else
1729           dist = 64;
1730       }
1731       else
1732       {
1733         if ( AF_LATIN_HINTS_DO_MONO( hints ) )
1734         {
1735           /* monochrome horizontal hinting: snap widths to integer pixels */
1736           /* with a different threshold                                   */
1737 
1738           if ( dist < 64 )
1739             dist = 64;
1740           else
1741             dist = ( dist + 32 ) & ~63;
1742         }
1743         else
1744         {
1745           /* for horizontal anti-aliased hinting, we adopt a more subtle */
1746           /* approach: we strengthen small stems, round stems whose size */
1747           /* is between 1 and 2 pixels to an integer, otherwise nothing  */
1748 
1749           if ( dist < 48 )
1750             dist = ( dist + 64 ) >> 1;
1751 
1752           else if ( dist < 128 )
1753           {
1754             /* We only round to an integer width if the corresponding */
1755             /* distortion is less than 1/4 pixel.  Otherwise this     */
1756             /* makes everything worse since the diagonals, which are  */
1757             /* not hinted, appear a lot bolder or thinner than the    */
1758             /* vertical stems.                                        */
1759 
1760             FT_Int  delta;
1761 
1762 
1763             dist = ( dist + 22 ) & ~63;
1764             delta = dist - org_dist;
1765             if ( delta < 0 )
1766               delta = -delta;
1767 
1768             if ( delta >= 16 )
1769             {
1770               dist = org_dist;
1771               if ( dist < 48 )
1772                 dist = ( dist + 64 ) >> 1;
1773             }
1774           }
1775           else
1776             /* round otherwise to prevent color fringes in LCD mode */
1777             dist = ( dist + 32 ) & ~63;
1778         }
1779       }
1780     }
1781 
1782   Done_Width:
1783     if ( sign )
1784       dist = -dist;
1785 
1786     return dist;
1787   }
1788 
1789 
1790   /* align one stem edge relative to the previous stem edge */
1791 
1792   static void
af_latin2_align_linked_edge(AF_GlyphHints hints,AF_Dimension dim,AF_Edge base_edge,AF_Edge stem_edge)1793   af_latin2_align_linked_edge( AF_GlyphHints  hints,
1794                                AF_Dimension   dim,
1795                                AF_Edge        base_edge,
1796                                AF_Edge        stem_edge )
1797   {
1798     FT_Pos  dist = stem_edge->opos - base_edge->opos;
1799 
1800     FT_Pos  fitted_width = af_latin2_compute_stem_width( hints, dim, dist,
1801                                                          base_edge->flags,
1802                                                          stem_edge->flags );
1803 
1804 
1805     stem_edge->pos = base_edge->pos + fitted_width;
1806 
1807     FT_TRACE5(( "LINK: edge %d (opos=%.2f) linked to (%.2f), "
1808                 "dist was %.2f, now %.2f\n",
1809                 stem_edge-hints->axis[dim].edges, stem_edge->opos / 64.0,
1810                 stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 ));
1811   }
1812 
1813 
1814   static void
af_latin2_align_serif_edge(AF_GlyphHints hints,AF_Edge base,AF_Edge serif)1815   af_latin2_align_serif_edge( AF_GlyphHints  hints,
1816                               AF_Edge        base,
1817                               AF_Edge        serif )
1818   {
1819     FT_UNUSED( hints );
1820 
1821     serif->pos = base->pos + ( serif->opos - base->opos );
1822   }
1823 
1824 
1825   /*************************************************************************/
1826   /*************************************************************************/
1827   /*************************************************************************/
1828   /****                                                                 ****/
1829   /****                    E D G E   H I N T I N G                      ****/
1830   /****                                                                 ****/
1831   /*************************************************************************/
1832   /*************************************************************************/
1833   /*************************************************************************/
1834 
1835 
1836   static void
af_latin2_hint_edges(AF_GlyphHints hints,AF_Dimension dim)1837   af_latin2_hint_edges( AF_GlyphHints  hints,
1838                         AF_Dimension   dim )
1839   {
1840     AF_AxisHints  axis       = &hints->axis[dim];
1841     AF_Edge       edges      = axis->edges;
1842     AF_Edge       edge_limit = edges + axis->num_edges;
1843     AF_Edge       edge;
1844     AF_Edge       anchor     = NULL;
1845     FT_Int        has_serifs = 0;
1846     FT_Pos        anchor_drift = 0;
1847 
1848 
1849 
1850     FT_TRACE5(( "==== hinting %s edges =====\n",
1851                 dim == AF_DIMENSION_HORZ ? "vertical" : "horizontal" ));
1852 
1853     /* we begin by aligning all stems relative to the blue zone */
1854     /* if needed -- that's only for horizontal edges            */
1855 
1856     if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) )
1857     {
1858       for ( edge = edges; edge < edge_limit; edge++ )
1859       {
1860         AF_Width  blue;
1861         AF_Edge   edge1, edge2;
1862 
1863 
1864         if ( edge->flags & AF_EDGE_DONE )
1865           continue;
1866 
1867         blue  = edge->blue_edge;
1868         edge1 = NULL;
1869         edge2 = edge->link;
1870 
1871         if ( blue )
1872         {
1873           edge1 = edge;
1874         }
1875         else if ( edge2 && edge2->blue_edge )
1876         {
1877           blue  = edge2->blue_edge;
1878           edge1 = edge2;
1879           edge2 = edge;
1880         }
1881 
1882         if ( !edge1 )
1883           continue;
1884 
1885         FT_TRACE5(( "BLUE: edge %d (opos=%.2f) snapped to (%.2f), "
1886                     "was (%.2f)\n",
1887                     edge1-edges, edge1->opos / 64.0, blue->fit / 64.0,
1888                     edge1->pos / 64.0 ));
1889 
1890         edge1->pos    = blue->fit;
1891         edge1->flags |= AF_EDGE_DONE;
1892 
1893         if ( edge2 && !edge2->blue_edge )
1894         {
1895           af_latin2_align_linked_edge( hints, dim, edge1, edge2 );
1896           edge2->flags |= AF_EDGE_DONE;
1897         }
1898 
1899         if ( !anchor )
1900         {
1901           anchor = edge;
1902 
1903           anchor_drift = ( anchor->pos - anchor->opos );
1904           if ( edge2 )
1905             anchor_drift = ( anchor_drift +
1906                              ( edge2->pos - edge2->opos ) ) >> 1;
1907         }
1908       }
1909     }
1910 
1911     /* now we will align all stem edges, trying to maintain the */
1912     /* relative order of stems in the glyph                     */
1913     for ( edge = edges; edge < edge_limit; edge++ )
1914     {
1915       AF_Edge  edge2;
1916 
1917 
1918       if ( edge->flags & AF_EDGE_DONE )
1919         continue;
1920 
1921       /* skip all non-stem edges */
1922       edge2 = edge->link;
1923       if ( !edge2 )
1924       {
1925         has_serifs++;
1926         continue;
1927       }
1928 
1929       /* now align the stem */
1930 
1931       /* this should not happen, but it's better to be safe */
1932       if ( edge2->blue_edge )
1933       {
1934         FT_TRACE5(( "ASSERTION FAILED for edge %d\n", edge2-edges ));
1935 
1936         af_latin2_align_linked_edge( hints, dim, edge2, edge );
1937         edge->flags |= AF_EDGE_DONE;
1938         continue;
1939       }
1940 
1941       if ( !anchor )
1942       {
1943         FT_Pos  org_len, org_center, cur_len;
1944         FT_Pos  cur_pos1, error1, error2, u_off, d_off;
1945 
1946 
1947         org_len = edge2->opos - edge->opos;
1948         cur_len = af_latin2_compute_stem_width( hints, dim, org_len,
1949                                                 edge->flags,
1950                                                 edge2->flags );
1951         if ( cur_len <= 64 )
1952           u_off = d_off = 32;
1953         else
1954         {
1955           u_off = 38;
1956           d_off = 26;
1957         }
1958 
1959         if ( cur_len < 96 )
1960         {
1961           org_center = edge->opos + ( org_len >> 1 );
1962 
1963           cur_pos1   = FT_PIX_ROUND( org_center );
1964 
1965           error1 = org_center - ( cur_pos1 - u_off );
1966           if ( error1 < 0 )
1967             error1 = -error1;
1968 
1969           error2 = org_center - ( cur_pos1 + d_off );
1970           if ( error2 < 0 )
1971             error2 = -error2;
1972 
1973           if ( error1 < error2 )
1974             cur_pos1 -= u_off;
1975           else
1976             cur_pos1 += d_off;
1977 
1978           edge->pos  = cur_pos1 - cur_len / 2;
1979           edge2->pos = edge->pos + cur_len;
1980         }
1981         else
1982           edge->pos = FT_PIX_ROUND( edge->opos );
1983 
1984         FT_TRACE5(( "ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)"
1985                     " snapped to (%.2f) (%.2f)\n",
1986                     edge-edges, edge->opos / 64.0,
1987                     edge2-edges, edge2->opos / 64.0,
1988                     edge->pos / 64.0, edge2->pos / 64.0 ));
1989         anchor = edge;
1990 
1991         edge->flags |= AF_EDGE_DONE;
1992 
1993         af_latin2_align_linked_edge( hints, dim, edge, edge2 );
1994 
1995         edge2->flags |= AF_EDGE_DONE;
1996 
1997         anchor_drift = ( ( anchor->pos - anchor->opos ) +
1998                          ( edge2->pos - edge2->opos ) ) >> 1;
1999 
2000         FT_TRACE5(( "DRIFT: %.2f\n", anchor_drift/64.0 ));
2001       }
2002       else
2003       {
2004         FT_Pos   org_pos, org_len, org_center, cur_center, cur_len;
2005         FT_Pos   org_left, org_right;
2006 
2007 
2008         org_pos    = edge->opos + anchor_drift;
2009         org_len    = edge2->opos - edge->opos;
2010         org_center = org_pos + ( org_len >> 1 );
2011 
2012         cur_len = af_latin2_compute_stem_width( hints, dim, org_len,
2013                                                 edge->flags,
2014                                                 edge2->flags );
2015 
2016         org_left  = org_pos + ( ( org_len - cur_len ) >> 1 );
2017         org_right = org_pos + ( ( org_len + cur_len ) >> 1 );
2018 
2019         FT_TRACE5(( "ALIGN: left=%.2f right=%.2f ",
2020                     org_left / 64.0, org_right / 64.0 ));
2021         cur_center = org_center;
2022 
2023         if ( edge2->flags & AF_EDGE_DONE )
2024         {
2025           FT_TRACE5(( "\n" ));
2026           edge->pos = edge2->pos - cur_len;
2027         }
2028         else
2029         {
2030          /* we want to compare several displacement, and choose
2031           * the one that increases fitness while minimizing
2032           * distortion as well
2033           */
2034           FT_Pos   displacements[6], scores[6], org, fit, delta;
2035           FT_UInt  count = 0;
2036 
2037           /* note: don't even try to fit tiny stems */
2038           if ( cur_len < 32 )
2039           {
2040             FT_TRACE5(( "tiny stem\n" ));
2041             goto AlignStem;
2042           }
2043 
2044           /* if the span is within a single pixel, don't touch it */
2045           if ( FT_PIX_FLOOR( org_left ) == FT_PIX_CEIL( org_right ) )
2046           {
2047             FT_TRACE5(( "single pixel stem\n" ));
2048             goto AlignStem;
2049           }
2050 
2051           if ( cur_len <= 96 )
2052           {
2053            /* we want to avoid the absolute worst case which is
2054             * when the left and right edges of the span each represent
2055             * about 50% of the gray. we'd better want to change this
2056             * to 25/75%, since this is much more pleasant to the eye with
2057             * very acceptable distortion
2058             */
2059             FT_Pos  frac_left  = org_left  & 63;
2060             FT_Pos  frac_right = org_right & 63;
2061 
2062             if ( frac_left  >= 22 && frac_left  <= 42 &&
2063                  frac_right >= 22 && frac_right <= 42 )
2064             {
2065               org = frac_left;
2066               fit = ( org <= 32 ) ? 16 : 48;
2067               delta = FT_ABS( fit - org );
2068               displacements[count] = fit - org;
2069               scores[count++]      = delta;
2070               FT_TRACE5(( "dispA=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2071 
2072               org = frac_right;
2073               fit = ( org <= 32 ) ? 16 : 48;
2074               delta = FT_ABS( fit - org );
2075               displacements[count] = fit - org;
2076               scores[count++]     = delta;
2077               FT_TRACE5(( "dispB=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2078             }
2079           }
2080 
2081           /* snapping the left edge to the grid */
2082           org   = org_left;
2083           fit   = FT_PIX_ROUND( org );
2084           delta = FT_ABS( fit - org );
2085           displacements[count] = fit - org;
2086           scores[count++]      = delta;
2087           FT_TRACE5(( "dispC=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2088 
2089           /* snapping the right edge to the grid */
2090           org   = org_right;
2091           fit   = FT_PIX_ROUND( org );
2092           delta = FT_ABS( fit - org );
2093           displacements[count] = fit - org;
2094           scores[count++]      = delta;
2095           FT_TRACE5(( "dispD=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2096 
2097           /* now find the best displacement */
2098           {
2099             FT_Pos  best_score = scores[0];
2100             FT_Pos  best_disp  = displacements[0];
2101             FT_UInt nn;
2102 
2103             for ( nn = 1; nn < count; nn++ )
2104             {
2105               if ( scores[nn] < best_score )
2106               {
2107                 best_score = scores[nn];
2108                 best_disp  = displacements[nn];
2109               }
2110             }
2111 
2112             cur_center = org_center + best_disp;
2113           }
2114           FT_TRACE5(( "\n" ));
2115         }
2116 
2117       AlignStem:
2118         edge->pos  = cur_center - ( cur_len >> 1 );
2119         edge2->pos = edge->pos + cur_len;
2120 
2121         FT_TRACE5(( "STEM1: %d (opos=%.2f) to %d (opos=%.2f)"
2122                     " snapped to (%.2f) and (%.2f),"
2123                     " org_len=%.2f cur_len=%.2f\n",
2124                     edge-edges, edge->opos / 64.0,
2125                     edge2-edges, edge2->opos / 64.0,
2126                     edge->pos / 64.0, edge2->pos / 64.0,
2127                     org_len / 64.0, cur_len / 64.0 ));
2128 
2129         edge->flags  |= AF_EDGE_DONE;
2130         edge2->flags |= AF_EDGE_DONE;
2131 
2132         if ( edge > edges && edge->pos < edge[-1].pos )
2133         {
2134           FT_TRACE5(( "BOUND: %d (pos=%.2f) to (%.2f)\n",
2135                       edge-edges, edge->pos / 64.0, edge[-1].pos / 64.0 ));
2136           edge->pos = edge[-1].pos;
2137         }
2138       }
2139     }
2140 
2141     /* make sure that lowercase m's maintain their symmetry */
2142 
2143     /* In general, lowercase m's have six vertical edges if they are sans */
2144     /* serif, or twelve if they are with serifs.  This implementation is  */
2145     /* based on that assumption, and seems to work very well with most    */
2146     /* faces.  However, if for a certain face this assumption is not      */
2147     /* true, the m is just rendered like before.  In addition, any stem   */
2148     /* correction will only be applied to symmetrical glyphs (even if the */
2149     /* glyph is not an m), so the potential for unwanted distortion is    */
2150     /* relatively low.                                                    */
2151 
2152     /* We don't handle horizontal edges since we can't easily assure that */
2153     /* the third (lowest) stem aligns with the base line; it might end up */
2154     /* one pixel higher or lower.                                         */
2155 
2156 #if 0
2157     {
2158       FT_Int  n_edges = edge_limit - edges;
2159 
2160 
2161       if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
2162       {
2163         AF_Edge  edge1, edge2, edge3;
2164         FT_Pos   dist1, dist2, span, delta;
2165 
2166 
2167         if ( n_edges == 6 )
2168         {
2169           edge1 = edges;
2170           edge2 = edges + 2;
2171           edge3 = edges + 4;
2172         }
2173         else
2174         {
2175           edge1 = edges + 1;
2176           edge2 = edges + 5;
2177           edge3 = edges + 9;
2178         }
2179 
2180         dist1 = edge2->opos - edge1->opos;
2181         dist2 = edge3->opos - edge2->opos;
2182 
2183         span = dist1 - dist2;
2184         if ( span < 0 )
2185           span = -span;
2186 
2187         if ( span < 8 )
2188         {
2189           delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
2190           edge3->pos -= delta;
2191           if ( edge3->link )
2192             edge3->link->pos -= delta;
2193 
2194           /* move the serifs along with the stem */
2195           if ( n_edges == 12 )
2196           {
2197             ( edges + 8 )->pos -= delta;
2198             ( edges + 11 )->pos -= delta;
2199           }
2200 
2201           edge3->flags |= AF_EDGE_DONE;
2202           if ( edge3->link )
2203             edge3->link->flags |= AF_EDGE_DONE;
2204         }
2205       }
2206     }
2207 #endif
2208 
2209     if ( has_serifs || !anchor )
2210     {
2211       /*
2212        *  now hint the remaining edges (serifs and single) in order
2213        *  to complete our processing
2214        */
2215       for ( edge = edges; edge < edge_limit; edge++ )
2216       {
2217         FT_Pos  delta;
2218 
2219 
2220         if ( edge->flags & AF_EDGE_DONE )
2221           continue;
2222 
2223         delta = 1000;
2224 
2225         if ( edge->serif )
2226         {
2227           delta = edge->serif->opos - edge->opos;
2228           if ( delta < 0 )
2229             delta = -delta;
2230         }
2231 
2232         if ( delta < 64 + 16 )
2233         {
2234           af_latin2_align_serif_edge( hints, edge->serif, edge );
2235           FT_TRACE5(( "SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)"
2236                       " aligned to (%.2f)\n",
2237                       edge-edges, edge->opos / 64.0,
2238                       edge->serif - edges, edge->serif->opos / 64.0,
2239                       edge->pos / 64.0 ));
2240         }
2241         else if ( !anchor )
2242         {
2243           FT_TRACE5(( "SERIF_ANCHOR: edge %d (opos=%.2f)"
2244                       " snapped to (%.2f)\n",
2245                       edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
2246           edge->pos = FT_PIX_ROUND( edge->opos );
2247           anchor    = edge;
2248         }
2249         else
2250         {
2251           AF_Edge  before, after;
2252 
2253 
2254           for ( before = edge - 1; before >= edges; before-- )
2255             if ( before->flags & AF_EDGE_DONE )
2256               break;
2257 
2258           for ( after = edge + 1; after < edge_limit; after++ )
2259             if ( after->flags & AF_EDGE_DONE )
2260               break;
2261 
2262           if ( before >= edges && before < edge   &&
2263                after < edge_limit && after > edge )
2264           {
2265             if ( after->opos == before->opos )
2266               edge->pos = before->pos;
2267             else
2268               edge->pos = before->pos +
2269                           FT_MulDiv( edge->opos - before->opos,
2270                                      after->pos - before->pos,
2271                                      after->opos - before->opos );
2272             FT_TRACE5(( "SERIF_LINK1: edge %d (opos=%.2f) snapped to (%.2f)"
2273                         " from %d (opos=%.2f)\n",
2274                         edge-edges, edge->opos / 64.0, edge->pos / 64.0,
2275                         before - edges, before->opos / 64.0 ));
2276           }
2277           else
2278           {
2279             edge->pos = anchor->pos +
2280                         ( ( edge->opos - anchor->opos + 16 ) & ~31 );
2281 
2282             FT_TRACE5(( "SERIF_LINK2: edge %d (opos=%.2f)"
2283                         " snapped to (%.2f)\n",
2284                         edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
2285           }
2286         }
2287 
2288         edge->flags |= AF_EDGE_DONE;
2289 
2290         if ( edge > edges && edge->pos < edge[-1].pos )
2291           edge->pos = edge[-1].pos;
2292 
2293         if ( edge + 1 < edge_limit        &&
2294              edge[1].flags & AF_EDGE_DONE &&
2295              edge->pos > edge[1].pos      )
2296           edge->pos = edge[1].pos;
2297       }
2298     }
2299   }
2300 
2301 
2302   static FT_Error
af_latin2_hints_apply(AF_GlyphHints hints,FT_Outline * outline,AF_LatinMetrics metrics)2303   af_latin2_hints_apply( AF_GlyphHints    hints,
2304                          FT_Outline*      outline,
2305                          AF_LatinMetrics  metrics )
2306   {
2307     FT_Error  error;
2308     int       dim;
2309 
2310 
2311     error = af_glyph_hints_reload( hints, outline );
2312     if ( error )
2313       goto Exit;
2314 
2315     /* analyze glyph outline */
2316 #ifdef AF_CONFIG_OPTION_USE_WARPER
2317     if ( ( metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT &&
2318            AF_HINTS_DO_WARP( hints )                                ) ||
2319          AF_HINTS_DO_HORIZONTAL( hints )                              )
2320 #else
2321     if ( AF_HINTS_DO_HORIZONTAL( hints ) )
2322 #endif
2323     {
2324       error = af_latin2_hints_detect_features( hints, AF_DIMENSION_HORZ );
2325       if ( error )
2326         goto Exit;
2327     }
2328 
2329     if ( AF_HINTS_DO_VERTICAL( hints ) )
2330     {
2331       error = af_latin2_hints_detect_features( hints, AF_DIMENSION_VERT );
2332       if ( error )
2333         goto Exit;
2334 
2335       af_latin2_hints_compute_blue_edges( hints, metrics );
2336     }
2337 
2338     /* grid-fit the outline */
2339     for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
2340     {
2341 #ifdef AF_CONFIG_OPTION_USE_WARPER
2342       if ( dim == AF_DIMENSION_HORZ                                 &&
2343            metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT &&
2344            AF_HINTS_DO_WARP( hints )                                )
2345       {
2346         AF_WarperRec  warper;
2347         FT_Fixed      scale;
2348         FT_Pos        delta;
2349 
2350 
2351         af_warper_compute( &warper, hints, dim, &scale, &delta );
2352         af_glyph_hints_scale_dim( hints, dim, scale, delta );
2353         continue;
2354       }
2355 #endif /* AF_CONFIG_OPTION_USE_WARPER */
2356 
2357       if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
2358            ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
2359       {
2360         af_latin2_hint_edges( hints, (AF_Dimension)dim );
2361         af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim );
2362         af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
2363         af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
2364       }
2365     }
2366     af_glyph_hints_save( hints, outline );
2367 
2368   Exit:
2369     return error;
2370   }
2371 
2372 
2373   /*************************************************************************/
2374   /*************************************************************************/
2375   /*****                                                               *****/
2376   /*****              L A T I N   S C R I P T   C L A S S              *****/
2377   /*****                                                               *****/
2378   /*************************************************************************/
2379   /*************************************************************************/
2380 
2381 
2382   AF_DEFINE_WRITING_SYSTEM_CLASS(
2383     af_latin2_writing_system_class,
2384 
2385     AF_WRITING_SYSTEM_LATIN2,
2386 
2387     sizeof ( AF_LatinMetricsRec ),
2388 
2389     (AF_WritingSystem_InitMetricsFunc) af_latin2_metrics_init,
2390     (AF_WritingSystem_ScaleMetricsFunc)af_latin2_metrics_scale,
2391     (AF_WritingSystem_DoneMetricsFunc) NULL,
2392 
2393     (AF_WritingSystem_InitHintsFunc)   af_latin2_hints_init,
2394     (AF_WritingSystem_ApplyHintsFunc)  af_latin2_hints_apply
2395   )
2396 
2397 
2398 /* END */
2399