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 2003-2016 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#include "afglobal.h"
27#include "aflatin.h"
28#include "aflatin2.h"
29#include "aferrors.h"
30
31
32#ifdef AF_CONFIG_OPTION_USE_WARPER
33#include "afwarp.h"
34#endif
35
36
37  /*************************************************************************/
38  /*                                                                       */
39  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
40  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
41  /* messages during execution.                                            */
42  /*                                                                       */
43#undef  FT_COMPONENT
44#define FT_COMPONENT  trace_aflatin2
45
46
47  FT_LOCAL_DEF( FT_Error )
48  af_latin2_hints_compute_segments( AF_GlyphHints  hints,
49                                    AF_Dimension   dim );
50
51  FT_LOCAL_DEF( void )
52  af_latin2_hints_link_segments( AF_GlyphHints  hints,
53                                 AF_Dimension   dim );
54
55  /*************************************************************************/
56  /*************************************************************************/
57  /*****                                                               *****/
58  /*****            L A T I N   G L O B A L   M E T R I C S            *****/
59  /*****                                                               *****/
60  /*************************************************************************/
61  /*************************************************************************/
62
63  FT_LOCAL_DEF( void )
64  af_latin2_metrics_init_widths( AF_LatinMetrics  metrics,
65                                 FT_Face          face )
66  {
67    /* scan the array of segments in each direction */
68    AF_GlyphHintsRec  hints[1];
69
70
71    af_glyph_hints_init( hints, face->memory );
72
73    metrics->axis[AF_DIMENSION_HORZ].width_count = 0;
74    metrics->axis[AF_DIMENSION_VERT].width_count = 0;
75
76    {
77      FT_Error             error;
78      FT_UInt              glyph_index;
79      int                  dim;
80      AF_LatinMetricsRec   dummy[1];
81      AF_Scaler            scaler = &dummy->root.scaler;
82
83
84      glyph_index = FT_Get_Char_Index(
85                      face,
86                      metrics->root.style_class->standard_char );
87      if ( glyph_index == 0 )
88        goto Exit;
89
90      error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
91      if ( error || face->glyph->outline.n_points <= 0 )
92        goto Exit;
93
94      FT_ZERO( dummy );
95
96      dummy->units_per_em = metrics->units_per_em;
97      scaler->x_scale     = scaler->y_scale = 0x10000L;
98      scaler->x_delta     = scaler->y_delta = 0;
99      scaler->face        = face;
100      scaler->render_mode = FT_RENDER_MODE_NORMAL;
101      scaler->flags       = 0;
102
103      af_glyph_hints_rescale( hints, (AF_StyleMetrics)dummy );
104
105      error = af_glyph_hints_reload( hints, &face->glyph->outline );
106      if ( error )
107        goto Exit;
108
109      for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
110      {
111        AF_LatinAxis  axis    = &metrics->axis[dim];
112        AF_AxisHints  axhints = &hints->axis[dim];
113        AF_Segment    seg, limit, link;
114        FT_UInt       num_widths = 0;
115
116
117        error = af_latin2_hints_compute_segments( hints,
118                                                 (AF_Dimension)dim );
119        if ( error )
120          goto Exit;
121
122        af_latin2_hints_link_segments( hints,
123                                      (AF_Dimension)dim );
124
125        seg   = axhints->segments;
126        limit = seg + axhints->num_segments;
127
128        for ( ; seg < limit; seg++ )
129        {
130          link = seg->link;
131
132          /* we only consider stem segments there! */
133          if ( link && link->link == seg && link > seg )
134          {
135            FT_Pos  dist;
136
137
138            dist = seg->pos - link->pos;
139            if ( dist < 0 )
140              dist = -dist;
141
142            if ( num_widths < AF_LATIN_MAX_WIDTHS )
143              axis->widths[num_widths++].org = dist;
144          }
145        }
146
147        af_sort_widths( num_widths, axis->widths );
148        axis->width_count = num_widths;
149      }
150
151  Exit:
152      for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
153      {
154        AF_LatinAxis  axis = &metrics->axis[dim];
155        FT_Pos        stdw;
156
157
158        stdw = ( axis->width_count > 0 )
159                 ? axis->widths[0].org
160                 : AF_LATIN_CONSTANT( metrics, 50 );
161
162        /* let's try 20% of the smallest width */
163        axis->edge_distance_threshold = stdw / 5;
164        axis->standard_width          = stdw;
165        axis->extra_light             = 0;
166      }
167    }
168
169    af_glyph_hints_done( hints );
170  }
171
172
173
174#define AF_LATIN_MAX_TEST_CHARACTERS  12
175
176
177  static const char af_latin2_blue_chars[AF_LATIN_MAX_BLUES]
178                                        [AF_LATIN_MAX_TEST_CHARACTERS+1] =
179  {
180    "THEZOCQS",
181    "HEZLOCUS",
182    "fijkdbh",
183    "xzroesc",
184    "xzroesc",
185    "pqgjy"
186  };
187
188
189  static void
190  af_latin2_metrics_init_blues( AF_LatinMetrics  metrics,
191                                FT_Face          face )
192  {
193    FT_Pos        flats [AF_LATIN_MAX_TEST_CHARACTERS];
194    FT_Pos        rounds[AF_LATIN_MAX_TEST_CHARACTERS];
195    FT_Int        num_flats;
196    FT_Int        num_rounds;
197    FT_Int        bb;
198    AF_LatinBlue  blue;
199    FT_Error      error;
200    AF_LatinAxis  axis  = &metrics->axis[AF_DIMENSION_VERT];
201    FT_GlyphSlot  glyph = face->glyph;
202
203
204    /* we compute the blues simply by loading each character from the     */
205    /* 'af_latin2_blue_chars[blues]' string, then compute its top-most or */
206    /* bottom-most points (depending on `AF_IS_TOP_BLUE')                 */
207
208    FT_TRACE5(( "blue zones computation\n"
209                "======================\n\n" ));
210
211    for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
212    {
213      const char*  p     = af_latin2_blue_chars[bb];
214      const char*  limit = p + AF_LATIN_MAX_TEST_CHARACTERS;
215      FT_Pos*      blue_ref;
216      FT_Pos*      blue_shoot;
217
218
219      FT_TRACE5(( "blue zone %d:\n", bb ));
220
221      num_flats  = 0;
222      num_rounds = 0;
223
224      for ( ; p < limit && *p; p++ )
225      {
226        FT_UInt     glyph_index;
227        FT_Int      best_point, best_y, best_first, best_last;
228        FT_Vector*  points;
229        FT_Bool     round;
230
231
232        /* load the character in the face -- skip unknown or empty ones */
233        glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p );
234        if ( glyph_index == 0 )
235          continue;
236
237        error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
238        if ( error || glyph->outline.n_points <= 0 )
239          continue;
240
241        /* now compute min or max point indices and coordinates */
242        points      = glyph->outline.points;
243        best_point  = -1;
244        best_y      = 0;  /* make compiler happy */
245        best_first  = 0;  /* ditto */
246        best_last   = 0;  /* ditto */
247
248        {
249          FT_Int  nn;
250          FT_Int  first = 0;
251          FT_Int  last  = -1;
252
253
254          for ( nn = 0; nn < glyph->outline.n_contours; first = last+1, nn++ )
255          {
256            FT_Int  old_best_point = best_point;
257            FT_Int  pp;
258
259
260            last = glyph->outline.contours[nn];
261
262            /* Avoid single-point contours since they are never rasterized. */
263            /* In some fonts, they correspond to mark attachment points     */
264            /* which are way outside of the glyph's real outline.           */
265            if ( last == first )
266                continue;
267
268            if ( AF_LATIN_IS_TOP_BLUE( bb ) )
269            {
270              for ( pp = first; pp <= last; pp++ )
271                if ( best_point < 0 || points[pp].y > best_y )
272                {
273                  best_point = pp;
274                  best_y     = points[pp].y;
275                }
276            }
277            else
278            {
279              for ( pp = first; pp <= last; pp++ )
280                if ( best_point < 0 || points[pp].y < best_y )
281                {
282                  best_point = pp;
283                  best_y     = points[pp].y;
284                }
285            }
286
287            if ( best_point != old_best_point )
288            {
289              best_first = first;
290              best_last  = last;
291            }
292          }
293          FT_TRACE5(( "  %c  %d", *p, best_y ));
294        }
295
296        /* now check whether the point belongs to a straight or round   */
297        /* segment; we first need to find in which contour the extremum */
298        /* lies, then inspect its previous and next points              */
299        {
300          FT_Pos  best_x = points[best_point].x;
301          FT_Int  start, end, prev, next;
302          FT_Pos  dist;
303
304
305          /* now look for the previous and next points that are not on the */
306          /* same Y coordinate.  Threshold the `closeness'...              */
307          start = end = best_point;
308
309          do
310          {
311            prev = start - 1;
312            if ( prev < best_first )
313              prev = best_last;
314
315            dist = FT_ABS( points[prev].y - best_y );
316            /* accept a small distance or a small angle (both values are */
317            /* heuristic; value 20 corresponds to approx. 2.9 degrees)   */
318            if ( dist > 5 )
319              if ( FT_ABS( points[prev].x - best_x ) <= 20 * dist )
320                break;
321
322            start = prev;
323
324          } while ( start != best_point );
325
326          do
327          {
328            next = end + 1;
329            if ( next > best_last )
330              next = best_first;
331
332            dist = FT_ABS( points[next].y - best_y );
333            if ( dist > 5 )
334              if ( FT_ABS( points[next].x - best_x ) <= 20 * dist )
335                break;
336
337            end = next;
338
339          } while ( end != best_point );
340
341          /* now, set the `round' flag depending on the segment's kind */
342          round = FT_BOOL(
343            FT_CURVE_TAG( glyph->outline.tags[start] ) != FT_CURVE_TAG_ON ||
344            FT_CURVE_TAG( glyph->outline.tags[ end ] ) != FT_CURVE_TAG_ON );
345
346          FT_TRACE5(( " (%s)\n", round ? "round" : "flat" ));
347        }
348
349        if ( round )
350          rounds[num_rounds++] = best_y;
351        else
352          flats[num_flats++]   = best_y;
353      }
354
355      if ( num_flats == 0 && num_rounds == 0 )
356      {
357        /*
358         *  we couldn't find a single glyph to compute this blue zone,
359         *  we will simply ignore it then
360         */
361        FT_TRACE5(( "  empty\n" ));
362        continue;
363      }
364
365      /* we have computed the contents of the `rounds' and `flats' tables, */
366      /* now determine the reference and overshoot position of the blue -- */
367      /* we simply take the median value after a simple sort               */
368      af_sort_pos( num_rounds, rounds );
369      af_sort_pos( num_flats,  flats );
370
371      blue       = & axis->blues[axis->blue_count];
372      blue_ref   = & blue->ref.org;
373      blue_shoot = & blue->shoot.org;
374
375      axis->blue_count++;
376
377      if ( num_flats == 0 )
378      {
379        *blue_ref   =
380        *blue_shoot = rounds[num_rounds / 2];
381      }
382      else if ( num_rounds == 0 )
383      {
384        *blue_ref   =
385        *blue_shoot = flats[num_flats / 2];
386      }
387      else
388      {
389        *blue_ref   = flats[num_flats / 2];
390        *blue_shoot = rounds[num_rounds / 2];
391      }
392
393      /* there are sometimes problems: if the overshoot position of top     */
394      /* zones is under its reference position, or the opposite for bottom  */
395      /* zones.  We must thus check everything there and correct the errors */
396      if ( *blue_shoot != *blue_ref )
397      {
398        FT_Pos   ref      = *blue_ref;
399        FT_Pos   shoot    = *blue_shoot;
400        FT_Bool  over_ref = FT_BOOL( shoot > ref );
401
402
403        if ( AF_LATIN_IS_TOP_BLUE( bb ) ^ over_ref )
404        {
405          *blue_ref   =
406          *blue_shoot = ( shoot + ref ) / 2;
407
408          FT_TRACE5(( "  [overshoot smaller than reference,"
409                      " taking mean value]\n" ));
410        }
411      }
412
413      blue->flags = 0;
414      if ( AF_LATIN_IS_TOP_BLUE( bb ) )
415        blue->flags |= AF_LATIN_BLUE_TOP;
416
417      /*
418       * The following flag is used later to adjust the y and x scales
419       * in order to optimize the pixel grid alignment of the top of small
420       * letters.
421       */
422      if ( AF_LATIN_IS_X_HEIGHT_BLUE( bb ) )
423        blue->flags |= AF_LATIN_BLUE_ADJUSTMENT;
424
425      FT_TRACE5(( "    -> reference = %ld\n"
426                  "       overshoot = %ld\n",
427                  *blue_ref, *blue_shoot ));
428    }
429
430    return;
431  }
432
433
434  FT_LOCAL_DEF( void )
435  af_latin2_metrics_check_digits( AF_LatinMetrics  metrics,
436                                  FT_Face          face )
437  {
438    FT_UInt   i;
439    FT_Bool   started = 0, same_width = 1;
440    FT_Fixed  advance, old_advance = 0;
441
442
443    /* check whether all ASCII digits have the same advance width; */
444    /* digit `0' is 0x30 in all supported charmaps                 */
445    for ( i = 0x30; i <= 0x39; i++ )
446    {
447      FT_UInt  glyph_index;
448
449
450      glyph_index = FT_Get_Char_Index( face, i );
451      if ( glyph_index == 0 )
452        continue;
453
454      if ( FT_Get_Advance( face, glyph_index,
455                           FT_LOAD_NO_SCALE         |
456                           FT_LOAD_NO_HINTING       |
457                           FT_LOAD_IGNORE_TRANSFORM,
458                           &advance ) )
459        continue;
460
461      if ( started )
462      {
463        if ( advance != old_advance )
464        {
465          same_width = 0;
466          break;
467        }
468      }
469      else
470      {
471        old_advance = advance;
472        started     = 1;
473      }
474    }
475
476    metrics->root.digits_have_same_width = same_width;
477  }
478
479
480  FT_LOCAL_DEF( FT_Error )
481  af_latin2_metrics_init( AF_LatinMetrics  metrics,
482                          FT_Face          face )
483  {
484    FT_Error    error  = FT_Err_Ok;
485    FT_CharMap  oldmap = face->charmap;
486    FT_UInt     ee;
487
488    static const FT_Encoding  latin_encodings[] =
489    {
490      FT_ENCODING_UNICODE,
491      FT_ENCODING_APPLE_ROMAN,
492      FT_ENCODING_ADOBE_STANDARD,
493      FT_ENCODING_ADOBE_LATIN_1,
494      FT_ENCODING_NONE  /* end of list */
495    };
496
497
498    metrics->units_per_em = face->units_per_EM;
499
500    /* do we have a latin charmap in there? */
501    for ( ee = 0; latin_encodings[ee] != FT_ENCODING_NONE; ee++ )
502    {
503      error = FT_Select_Charmap( face, latin_encodings[ee] );
504      if ( !error )
505        break;
506    }
507
508    if ( !error )
509    {
510      af_latin2_metrics_init_widths( metrics, face );
511      af_latin2_metrics_init_blues( metrics, face );
512      af_latin2_metrics_check_digits( metrics, face );
513    }
514
515    FT_Set_Charmap( face, oldmap );
516    return FT_Err_Ok;
517  }
518
519
520  static void
521  af_latin2_metrics_scale_dim( AF_LatinMetrics  metrics,
522                               AF_Scaler        scaler,
523                               AF_Dimension     dim )
524  {
525    FT_Fixed      scale;
526    FT_Pos        delta;
527    AF_LatinAxis  axis;
528    FT_UInt       nn;
529
530
531    if ( dim == AF_DIMENSION_HORZ )
532    {
533      scale = scaler->x_scale;
534      delta = scaler->x_delta;
535    }
536    else
537    {
538      scale = scaler->y_scale;
539      delta = scaler->y_delta;
540    }
541
542    axis = &metrics->axis[dim];
543
544    if ( axis->org_scale == scale && axis->org_delta == delta )
545      return;
546
547    axis->org_scale = scale;
548    axis->org_delta = delta;
549
550    /*
551     * correct Y scale to optimize the alignment of the top of small
552     * letters to the pixel grid
553     */
554    if ( dim == AF_DIMENSION_VERT )
555    {
556      AF_LatinAxis  vaxis = &metrics->axis[AF_DIMENSION_VERT];
557      AF_LatinBlue  blue = NULL;
558
559
560      for ( nn = 0; nn < vaxis->blue_count; nn++ )
561      {
562        if ( vaxis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT )
563        {
564          blue = &vaxis->blues[nn];
565          break;
566        }
567      }
568
569      if ( blue )
570      {
571        FT_Pos   scaled;
572        FT_Pos   threshold;
573        FT_Pos   fitted;
574        FT_UInt  limit;
575        FT_UInt  ppem;
576
577
578        scaled    = FT_MulFix( blue->shoot.org, scaler->y_scale );
579        ppem      = metrics->root.scaler.face->size->metrics.x_ppem;
580        limit     = metrics->root.globals->increase_x_height;
581        threshold = 40;
582
583        /* if the `increase-x-height' property is active, */
584        /* we round up much more often                    */
585        if ( limit                                 &&
586             ppem <= limit                         &&
587             ppem >= AF_PROP_INCREASE_X_HEIGHT_MIN )
588          threshold = 52;
589
590        fitted = ( scaled + threshold ) & ~63;
591
592#if 1
593        if ( scaled != fitted )
594        {
595          scale = FT_MulDiv( scale, fitted, scaled );
596          FT_TRACE5(( "== scaled x-top = %.2g"
597                      "  fitted = %.2g, scaling = %.4g\n",
598                      scaled / 64.0, fitted / 64.0,
599                      ( fitted * 1.0 ) / scaled ));
600        }
601#endif
602      }
603    }
604
605    axis->scale = scale;
606    axis->delta = delta;
607
608    if ( dim == AF_DIMENSION_HORZ )
609    {
610      metrics->root.scaler.x_scale = scale;
611      metrics->root.scaler.x_delta = delta;
612    }
613    else
614    {
615      metrics->root.scaler.y_scale = scale;
616      metrics->root.scaler.y_delta = delta;
617    }
618
619    /* scale the standard widths */
620    for ( nn = 0; nn < axis->width_count; nn++ )
621    {
622      AF_Width  width = axis->widths + nn;
623
624
625      width->cur = FT_MulFix( width->org, scale );
626      width->fit = width->cur;
627    }
628
629    /* an extra-light axis corresponds to a standard width that is */
630    /* smaller than 5/8 pixels                                     */
631    axis->extra_light =
632      (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 );
633
634    if ( dim == AF_DIMENSION_VERT )
635    {
636      /* scale the blue zones */
637      for ( nn = 0; nn < axis->blue_count; nn++ )
638      {
639        AF_LatinBlue  blue = &axis->blues[nn];
640        FT_Pos        dist;
641
642
643        blue->ref.cur   = FT_MulFix( blue->ref.org, scale ) + delta;
644        blue->ref.fit   = blue->ref.cur;
645        blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
646        blue->shoot.fit = blue->shoot.cur;
647        blue->flags    &= ~AF_LATIN_BLUE_ACTIVE;
648
649        /* a blue zone is only active if it is less than 3/4 pixels tall */
650        dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
651        if ( dist <= 48 && dist >= -48 )
652        {
653          FT_Pos  delta1, delta2;
654
655          delta1 = blue->shoot.org - blue->ref.org;
656          delta2 = delta1;
657          if ( delta1 < 0 )
658            delta2 = -delta2;
659
660          delta2 = FT_MulFix( delta2, scale );
661
662          if ( delta2 < 32 )
663            delta2 = 0;
664          else if ( delta2 < 64 )
665            delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
666          else
667            delta2 = FT_PIX_ROUND( delta2 );
668
669          if ( delta1 < 0 )
670            delta2 = -delta2;
671
672          blue->ref.fit   = FT_PIX_ROUND( blue->ref.cur );
673          blue->shoot.fit = blue->ref.fit + delta2;
674
675          FT_TRACE5(( ">> activating blue zone %d:"
676                      "  ref.cur=%.2g ref.fit=%.2g"
677                      "  shoot.cur=%.2g shoot.fit=%.2g\n",
678                      nn, blue->ref.cur / 64.0, blue->ref.fit / 64.0,
679                      blue->shoot.cur / 64.0, blue->shoot.fit / 64.0 ));
680
681          blue->flags |= AF_LATIN_BLUE_ACTIVE;
682        }
683      }
684    }
685  }
686
687
688  FT_LOCAL_DEF( void )
689  af_latin2_metrics_scale( AF_LatinMetrics  metrics,
690                           AF_Scaler        scaler )
691  {
692    metrics->root.scaler.render_mode = scaler->render_mode;
693    metrics->root.scaler.face        = scaler->face;
694    metrics->root.scaler.flags       = scaler->flags;
695
696    af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
697    af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
698  }
699
700
701  /* Extract standard_width from writing system/script specific */
702  /* metrics class.                                             */
703
704  FT_LOCAL_DEF( void )
705  af_latin2_get_standard_widths( AF_LatinMetrics  metrics,
706                                 FT_Pos*          stdHW,
707                                 FT_Pos*          stdVW )
708  {
709    if ( stdHW )
710      *stdHW = metrics->axis[AF_DIMENSION_VERT].standard_width;
711
712    if ( stdVW )
713      *stdVW = metrics->axis[AF_DIMENSION_HORZ].standard_width;
714  }
715
716
717  /*************************************************************************/
718  /*************************************************************************/
719  /*****                                                               *****/
720  /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
721  /*****                                                               *****/
722  /*************************************************************************/
723  /*************************************************************************/
724
725#define  SORT_SEGMENTS
726
727  FT_LOCAL_DEF( FT_Error )
728  af_latin2_hints_compute_segments( AF_GlyphHints  hints,
729                                    AF_Dimension   dim )
730  {
731    AF_AxisHints  axis          = &hints->axis[dim];
732    FT_Memory     memory        = hints->memory;
733    FT_Error      error         = FT_Err_Ok;
734    AF_Segment    segment       = NULL;
735    AF_SegmentRec seg0;
736    AF_Point*     contour       = hints->contours;
737    AF_Point*     contour_limit = contour + hints->num_contours;
738    AF_Direction  major_dir, segment_dir;
739
740
741    FT_ZERO( &seg0 );
742    seg0.score = 32000;
743    seg0.flags = AF_EDGE_NORMAL;
744
745    major_dir   = (AF_Direction)FT_ABS( axis->major_dir );
746    segment_dir = major_dir;
747
748    axis->num_segments = 0;
749
750    /* set up (u,v) in each point */
751    if ( dim == AF_DIMENSION_HORZ )
752    {
753      AF_Point  point = hints->points;
754      AF_Point  limit = point + hints->num_points;
755
756
757      for ( ; point < limit; point++ )
758      {
759        point->u = point->fx;
760        point->v = point->fy;
761      }
762    }
763    else
764    {
765      AF_Point  point = hints->points;
766      AF_Point  limit = point + hints->num_points;
767
768
769      for ( ; point < limit; point++ )
770      {
771        point->u = point->fy;
772        point->v = point->fx;
773      }
774    }
775
776    /* do each contour separately */
777    for ( ; contour < contour_limit; contour++ )
778    {
779      AF_Point  point   =  contour[0];
780      AF_Point  start   =  point;
781      AF_Point  last    =  point->prev;
782
783
784      if ( point == last )  /* skip singletons -- just in case */
785        continue;
786
787      /* already on an edge ?, backtrack to find its start */
788      if ( FT_ABS( point->in_dir ) == major_dir )
789      {
790        point = point->prev;
791
792        while ( point->in_dir == start->in_dir )
793          point = point->prev;
794      }
795      else  /* otherwise, find first segment start, if any */
796      {
797        while ( FT_ABS( point->out_dir ) != major_dir )
798        {
799          point = point->next;
800
801          if ( point == start )
802            goto NextContour;
803        }
804      }
805
806      start = point;
807
808      for  (;;)
809      {
810        AF_Point  first;
811        FT_Pos    min_u, min_v, max_u, max_v;
812
813        /* we're at the start of a new segment */
814        FT_ASSERT( FT_ABS( point->out_dir ) == major_dir &&
815                           point->in_dir != point->out_dir );
816        first = point;
817
818        min_u = max_u = point->u;
819        min_v = max_v = point->v;
820
821        point = point->next;
822
823        while ( point->out_dir == first->out_dir )
824        {
825          point = point->next;
826
827          if ( point->u < min_u )
828            min_u = point->u;
829
830          if ( point->u > max_u )
831            max_u = point->u;
832        }
833
834        if ( point->v < min_v )
835          min_v = point->v;
836
837        if ( point->v > max_v )
838          max_v = point->v;
839
840        /* record new segment */
841        error = af_axis_hints_new_segment( axis, memory, &segment );
842        if ( error )
843          goto Exit;
844
845        segment[0]         = seg0;
846        segment->dir       = first->out_dir;
847        segment->first     = first;
848        segment->last      = point;
849        segment->pos       = (FT_Short)( ( min_u + max_u ) >> 1 );
850        segment->min_coord = (FT_Short) min_v;
851        segment->max_coord = (FT_Short) max_v;
852        segment->height    = (FT_Short)( max_v - min_v );
853
854        /* a segment is round if it doesn't have successive */
855        /* on-curve points.                                 */
856        {
857          AF_Point  pt   = first;
858          AF_Point  last = point;
859          FT_UInt   f0   = pt->flags & AF_FLAG_CONTROL;
860          FT_UInt   f1;
861
862
863          segment->flags &= ~AF_EDGE_ROUND;
864
865          for ( ; pt != last; f0 = f1 )
866          {
867            pt = pt->next;
868            f1 = pt->flags & AF_FLAG_CONTROL;
869
870            if ( !f0 && !f1 )
871              break;
872
873            if ( pt == last )
874              segment->flags |= AF_EDGE_ROUND;
875          }
876        }
877
878       /* this can happen in the case of a degenerate contour
879        * e.g. a 2-point vertical contour
880        */
881        if ( point == start )
882          break;
883
884        /* jump to the start of the next segment, if any */
885        while ( FT_ABS( point->out_dir ) != major_dir )
886        {
887          point = point->next;
888
889          if ( point == start )
890            goto NextContour;
891        }
892      }
893
894    NextContour:
895      ;
896    } /* contours */
897
898    /* now slightly increase the height of segments when this makes */
899    /* sense -- this is used to better detect and ignore serifs     */
900    {
901      AF_Segment  segments     = axis->segments;
902      AF_Segment  segments_end = segments + axis->num_segments;
903
904
905      for ( segment = segments; segment < segments_end; segment++ )
906      {
907        AF_Point  first   = segment->first;
908        AF_Point  last    = segment->last;
909        AF_Point  p;
910        FT_Pos    first_v = first->v;
911        FT_Pos    last_v  = last->v;
912
913
914        if ( first_v < last_v )
915        {
916          p = first->prev;
917          if ( p->v < first_v )
918            segment->height = (FT_Short)( segment->height +
919                                          ( ( first_v - p->v ) >> 1 ) );
920
921          p = last->next;
922          if ( p->v > last_v )
923            segment->height = (FT_Short)( segment->height +
924                                          ( ( p->v - last_v ) >> 1 ) );
925        }
926        else
927        {
928          p = first->prev;
929          if ( p->v > first_v )
930            segment->height = (FT_Short)( segment->height +
931                                          ( ( p->v - first_v ) >> 1 ) );
932
933          p = last->next;
934          if ( p->v < last_v )
935            segment->height = (FT_Short)( segment->height +
936                                          ( ( last_v - p->v ) >> 1 ) );
937        }
938      }
939    }
940
941#ifdef AF_SORT_SEGMENTS
942   /* place all segments with a negative direction to the start
943    * of the array, used to speed up segment linking later...
944    */
945    {
946      AF_Segment  segments = axis->segments;
947      FT_UInt     count    = axis->num_segments;
948      FT_UInt     ii, jj;
949
950      for ( ii = 0; ii < count; ii++ )
951      {
952        if ( segments[ii].dir > 0 )
953        {
954          for ( jj = ii + 1; jj < count; jj++ )
955          {
956            if ( segments[jj].dir < 0 )
957            {
958              AF_SegmentRec  tmp;
959
960
961              tmp          = segments[ii];
962              segments[ii] = segments[jj];
963              segments[jj] = tmp;
964
965              break;
966            }
967          }
968
969          if ( jj == count )
970            break;
971        }
972      }
973      axis->mid_segments = ii;
974    }
975#endif
976
977  Exit:
978    return error;
979  }
980
981
982  FT_LOCAL_DEF( void )
983  af_latin2_hints_link_segments( AF_GlyphHints  hints,
984                                 AF_Dimension   dim )
985  {
986    AF_AxisHints  axis          = &hints->axis[dim];
987    AF_Segment    segments      = axis->segments;
988    AF_Segment    segment_limit = segments + axis->num_segments;
989#ifdef AF_SORT_SEGMENTS
990    AF_Segment    segment_mid   = segments + axis->mid_segments;
991#endif
992    FT_Pos        len_threshold, len_score;
993    AF_Segment    seg1, seg2;
994
995
996    len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
997    if ( len_threshold == 0 )
998      len_threshold = 1;
999
1000    len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 );
1001
1002#ifdef AF_SORT_SEGMENTS
1003    for ( seg1 = segments; seg1 < segment_mid; seg1++ )
1004    {
1005      if ( seg1->dir != axis->major_dir )
1006        continue;
1007
1008      for ( seg2 = segment_mid; seg2 < segment_limit; seg2++ )
1009#else
1010    /* now compare each segment to the others */
1011    for ( seg1 = segments; seg1 < segment_limit; seg1++ )
1012    {
1013      if ( seg1->dir != axis->major_dir )
1014        continue;
1015
1016      for ( seg2 = segments; seg2 < segment_limit; seg2++ )
1017        if ( seg1->dir + seg2->dir == 0 && seg2->pos > seg1->pos )
1018#endif
1019        {
1020          FT_Pos  pos1 = seg1->pos;
1021          FT_Pos  pos2 = seg2->pos;
1022          FT_Pos  dist = pos2 - pos1;
1023
1024
1025          if ( dist < 0 )
1026            continue;
1027
1028          {
1029            FT_Pos  min = seg1->min_coord;
1030            FT_Pos  max = seg1->max_coord;
1031            FT_Pos  len, score;
1032
1033
1034            if ( min < seg2->min_coord )
1035              min = seg2->min_coord;
1036
1037            if ( max > seg2->max_coord )
1038              max = seg2->max_coord;
1039
1040            len = max - min;
1041            if ( len >= len_threshold )
1042            {
1043              score = dist + len_score / len;
1044              if ( score < seg1->score )
1045              {
1046                seg1->score = score;
1047                seg1->link  = seg2;
1048              }
1049
1050              if ( score < seg2->score )
1051              {
1052                seg2->score = score;
1053                seg2->link  = seg1;
1054              }
1055            }
1056          }
1057        }
1058    }
1059#if 0
1060    }
1061#endif
1062
1063    /* now, compute the `serif' segments */
1064    for ( seg1 = segments; seg1 < segment_limit; seg1++ )
1065    {
1066      seg2 = seg1->link;
1067
1068      if ( seg2 )
1069      {
1070        if ( seg2->link != seg1 )
1071        {
1072          seg1->link  = NULL;
1073          seg1->serif = seg2->link;
1074        }
1075      }
1076    }
1077  }
1078
1079
1080  FT_LOCAL_DEF( FT_Error )
1081  af_latin2_hints_compute_edges( AF_GlyphHints  hints,
1082                                 AF_Dimension   dim )
1083  {
1084    AF_AxisHints  axis   = &hints->axis[dim];
1085    FT_Error      error  = FT_Err_Ok;
1086    FT_Memory     memory = hints->memory;
1087    AF_LatinAxis  laxis  = &((AF_LatinMetrics)hints->metrics)->axis[dim];
1088
1089    AF_Segment    segments      = axis->segments;
1090    AF_Segment    segment_limit = segments + axis->num_segments;
1091    AF_Segment    seg;
1092
1093    AF_Direction  up_dir;
1094    FT_Fixed      scale;
1095    FT_Pos        edge_distance_threshold;
1096    FT_Pos        segment_length_threshold;
1097
1098
1099    axis->num_edges = 0;
1100
1101    scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
1102                                         : hints->y_scale;
1103
1104    up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP
1105                                          : AF_DIR_RIGHT;
1106
1107    /*
1108     *  We want to ignore very small (mostly serif) segments, we do that
1109     *  by ignoring those that whose length is less than a given fraction
1110     *  of the standard width. If there is no standard width, we ignore
1111     *  those that are less than a given size in pixels
1112     *
1113     *  also, unlink serif segments that are linked to segments farther
1114     *  than 50% of the standard width
1115     */
1116    if ( dim == AF_DIMENSION_HORZ )
1117    {
1118      if ( laxis->width_count > 0 )
1119        segment_length_threshold = ( laxis->standard_width * 10 ) >> 4;
1120      else
1121        segment_length_threshold = FT_DivFix( 64, hints->y_scale );
1122    }
1123    else
1124      segment_length_threshold = 0;
1125
1126    /*********************************************************************/
1127    /*                                                                   */
1128    /* We will begin by generating a sorted table of edges for the       */
1129    /* current direction.  To do so, we simply scan each segment and try */
1130    /* to find an edge in our table that corresponds to its position.    */
1131    /*                                                                   */
1132    /* If no edge is found, we create and insert a new edge in the       */
1133    /* sorted table.  Otherwise, we simply add the segment to the edge's */
1134    /* list which will be processed in the second step to compute the    */
1135    /* edge's properties.                                                */
1136    /*                                                                   */
1137    /* Note that the edges table is sorted along the segment/edge        */
1138    /* position.                                                         */
1139    /*                                                                   */
1140    /*********************************************************************/
1141
1142    edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
1143                                         scale );
1144    if ( edge_distance_threshold > 64 / 4 )
1145      edge_distance_threshold = 64 / 4;
1146
1147    edge_distance_threshold = FT_DivFix( edge_distance_threshold,
1148                                         scale );
1149
1150    for ( seg = segments; seg < segment_limit; seg++ )
1151    {
1152      AF_Edge  found = NULL;
1153      FT_Int   ee;
1154
1155
1156      if ( seg->height < segment_length_threshold )
1157        continue;
1158
1159      /* A special case for serif edges: If they are smaller than */
1160      /* 1.5 pixels we ignore them.                               */
1161      if ( seg->serif )
1162      {
1163        FT_Pos  dist = seg->serif->pos - seg->pos;
1164
1165
1166        if ( dist < 0 )
1167          dist = -dist;
1168
1169        if ( dist >= laxis->standard_width >> 1 )
1170        {
1171          /* unlink this serif, it is too distant from its reference stem */
1172          seg->serif = NULL;
1173        }
1174        else if ( 2*seg->height < 3 * segment_length_threshold )
1175          continue;
1176      }
1177
1178      /* look for an edge corresponding to the segment */
1179      for ( ee = 0; ee < axis->num_edges; ee++ )
1180      {
1181        AF_Edge  edge = axis->edges + ee;
1182        FT_Pos   dist;
1183
1184
1185        dist = seg->pos - edge->fpos;
1186        if ( dist < 0 )
1187          dist = -dist;
1188
1189        if ( dist < edge_distance_threshold && edge->dir == seg->dir )
1190        {
1191          found = edge;
1192          break;
1193        }
1194      }
1195
1196      if ( !found )
1197      {
1198        AF_Edge   edge;
1199
1200
1201        /* insert a new edge in the list and */
1202        /* sort according to the position    */
1203        error = af_axis_hints_new_edge( axis, seg->pos, seg->dir, 0,
1204                                        memory, &edge );
1205        if ( error )
1206          goto Exit;
1207
1208        /* add the segment to the new edge's list */
1209        FT_ZERO( edge );
1210
1211        edge->first    = seg;
1212        edge->last     = seg;
1213        edge->dir      = seg->dir;
1214        edge->fpos     = seg->pos;
1215        edge->opos     = FT_MulFix( seg->pos, scale );
1216        edge->pos      = edge->opos;
1217        seg->edge_next = seg;
1218      }
1219      else
1220      {
1221        /* if an edge was found, simply add the segment to the edge's */
1222        /* list                                                       */
1223        seg->edge_next         = found->first;
1224        found->last->edge_next = seg;
1225        found->last            = seg;
1226      }
1227    }
1228
1229
1230    /*********************************************************************/
1231    /*                                                                   */
1232    /* Good, we will now compute each edge's properties according to     */
1233    /* segments found on its position.  Basically, these are:            */
1234    /*                                                                   */
1235    /*  - edge's main direction                                          */
1236    /*  - stem edge, serif edge or both (which defaults to stem then)    */
1237    /*  - rounded edge, straight or both (which defaults to straight)    */
1238    /*  - link for edge                                                  */
1239    /*                                                                   */
1240    /*********************************************************************/
1241
1242    /* first of all, set the `edge' field in each segment -- this is */
1243    /* required in order to compute edge links                       */
1244
1245    /*
1246     * Note that removing this loop and setting the `edge' field of each
1247     * segment directly in the code above slows down execution speed for
1248     * some reasons on platforms like the Sun.
1249     */
1250    {
1251      AF_Edge  edges      = axis->edges;
1252      AF_Edge  edge_limit = edges + axis->num_edges;
1253      AF_Edge  edge;
1254
1255
1256      for ( edge = edges; edge < edge_limit; edge++ )
1257      {
1258        seg = edge->first;
1259        if ( seg )
1260          do
1261          {
1262            seg->edge = edge;
1263            seg       = seg->edge_next;
1264
1265          } while ( seg != edge->first );
1266      }
1267
1268      /* now, compute each edge properties */
1269      for ( edge = edges; edge < edge_limit; edge++ )
1270      {
1271        FT_Int  is_round    = 0;  /* does it contain round segments?    */
1272        FT_Int  is_straight = 0;  /* does it contain straight segments? */
1273#if 0
1274        FT_Pos  ups         = 0;  /* number of upwards segments         */
1275        FT_Pos  downs       = 0;  /* number of downwards segments       */
1276#endif
1277
1278
1279        seg = edge->first;
1280
1281        do
1282        {
1283          FT_Bool  is_serif;
1284
1285
1286          /* check for roundness of segment */
1287          if ( seg->flags & AF_EDGE_ROUND )
1288            is_round++;
1289          else
1290            is_straight++;
1291
1292#if 0
1293          /* check for segment direction */
1294          if ( seg->dir == up_dir )
1295            ups   += seg->max_coord-seg->min_coord;
1296          else
1297            downs += seg->max_coord-seg->min_coord;
1298#endif
1299
1300          /* check for links -- if seg->serif is set, then seg->link must */
1301          /* be ignored                                                   */
1302          is_serif = (FT_Bool)( seg->serif               &&
1303                                seg->serif->edge         &&
1304                                seg->serif->edge != edge );
1305
1306          if ( ( seg->link && seg->link->edge != NULL ) || is_serif )
1307          {
1308            AF_Edge     edge2;
1309            AF_Segment  seg2;
1310
1311
1312            edge2 = edge->link;
1313            seg2  = seg->link;
1314
1315            if ( is_serif )
1316            {
1317              seg2  = seg->serif;
1318              edge2 = edge->serif;
1319            }
1320
1321            if ( edge2 )
1322            {
1323              FT_Pos  edge_delta;
1324              FT_Pos  seg_delta;
1325
1326
1327              edge_delta = edge->fpos - edge2->fpos;
1328              if ( edge_delta < 0 )
1329                edge_delta = -edge_delta;
1330
1331              seg_delta = seg->pos - seg2->pos;
1332              if ( seg_delta < 0 )
1333                seg_delta = -seg_delta;
1334
1335              if ( seg_delta < edge_delta )
1336                edge2 = seg2->edge;
1337            }
1338            else
1339              edge2 = seg2->edge;
1340
1341            if ( is_serif )
1342            {
1343              edge->serif   = edge2;
1344              edge2->flags |= AF_EDGE_SERIF;
1345            }
1346            else
1347              edge->link  = edge2;
1348          }
1349
1350          seg = seg->edge_next;
1351
1352        } while ( seg != edge->first );
1353
1354        /* set the round/straight flags */
1355        edge->flags = AF_EDGE_NORMAL;
1356
1357        if ( is_round > 0 && is_round >= is_straight )
1358          edge->flags |= AF_EDGE_ROUND;
1359
1360#if 0
1361        /* set the edge's main direction */
1362        edge->dir = AF_DIR_NONE;
1363
1364        if ( ups > downs )
1365          edge->dir = (FT_Char)up_dir;
1366
1367        else if ( ups < downs )
1368          edge->dir = (FT_Char)-up_dir;
1369
1370        else if ( ups == downs )
1371          edge->dir = 0;  /* both up and down! */
1372#endif
1373
1374        /* gets rid of serifs if link is set                */
1375        /* XXX: This gets rid of many unpleasant artefacts! */
1376        /*      Example: the `c' in cour.pfa at size 13     */
1377
1378        if ( edge->serif && edge->link )
1379          edge->serif = NULL;
1380      }
1381    }
1382
1383  Exit:
1384    return error;
1385  }
1386
1387
1388  FT_LOCAL_DEF( FT_Error )
1389  af_latin2_hints_detect_features( AF_GlyphHints  hints,
1390                                   AF_Dimension   dim )
1391  {
1392    FT_Error  error;
1393
1394
1395    error = af_latin2_hints_compute_segments( hints, dim );
1396    if ( !error )
1397    {
1398      af_latin2_hints_link_segments( hints, dim );
1399
1400      error = af_latin2_hints_compute_edges( hints, dim );
1401    }
1402    return error;
1403  }
1404
1405
1406  static void
1407  af_latin2_hints_compute_blue_edges( AF_GlyphHints    hints,
1408                                      AF_LatinMetrics  metrics )
1409  {
1410    AF_AxisHints  axis       = &hints->axis[AF_DIMENSION_VERT];
1411    AF_Edge       edge       = axis->edges;
1412    AF_Edge       edge_limit = edge + axis->num_edges;
1413    AF_LatinAxis  latin      = &metrics->axis[AF_DIMENSION_VERT];
1414    FT_Fixed      scale      = latin->scale;
1415    FT_Pos        best_dist0;  /* initial threshold */
1416
1417
1418    /* compute the initial threshold as a fraction of the EM size */
1419    best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
1420
1421    if ( best_dist0 > 64 / 2 )
1422      best_dist0 = 64 / 2;
1423
1424    /* compute which blue zones are active, i.e. have their scaled */
1425    /* size < 3/4 pixels                                           */
1426
1427    /* for each horizontal edge search the blue zone which is closest */
1428    for ( ; edge < edge_limit; edge++ )
1429    {
1430      FT_Int    bb;
1431      AF_Width  best_blue = NULL;
1432      FT_Pos    best_dist = best_dist0;
1433
1434      for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
1435      {
1436        AF_LatinBlue  blue = latin->blues + bb;
1437        FT_Bool       is_top_blue, is_major_dir;
1438
1439
1440        /* skip inactive blue zones (i.e., those that are too small) */
1441        if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) )
1442          continue;
1443
1444        /* if it is a top zone, check for right edges -- if it is a bottom */
1445        /* zone, check for left edges                                      */
1446        /*                                                                 */
1447        /* of course, that's for TrueType                                  */
1448        is_top_blue  = (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 );
1449        is_major_dir = FT_BOOL( edge->dir == axis->major_dir );
1450
1451        /* if it is a top zone, the edge must be against the major    */
1452        /* direction; if it is a bottom zone, it must be in the major */
1453        /* direction                                                  */
1454        if ( is_top_blue ^ is_major_dir )
1455        {
1456          FT_Pos     dist;
1457          AF_Width   compare;
1458
1459
1460          /* if it's a rounded edge, compare it to the overshoot position */
1461          /* if it's a flat edge, compare it to the reference position    */
1462          if ( edge->flags & AF_EDGE_ROUND )
1463            compare = &blue->shoot;
1464          else
1465            compare = &blue->ref;
1466
1467          dist = edge->fpos - compare->org;
1468          if ( dist < 0 )
1469            dist = -dist;
1470
1471          dist = FT_MulFix( dist, scale );
1472          if ( dist < best_dist )
1473          {
1474            best_dist = dist;
1475            best_blue = compare;
1476          }
1477
1478#if 0
1479          /* now, compare it to the overshoot position if the edge is     */
1480          /* rounded, and if the edge is over the reference position of a */
1481          /* top zone, or under the reference position of a bottom zone   */
1482          if ( edge->flags & AF_EDGE_ROUND && dist != 0 )
1483          {
1484            FT_Bool  is_under_ref = FT_BOOL( edge->fpos < blue->ref.org );
1485
1486
1487            if ( is_top_blue ^ is_under_ref )
1488            {
1489              blue = latin->blues + bb;
1490              dist = edge->fpos - blue->shoot.org;
1491              if ( dist < 0 )
1492                dist = -dist;
1493
1494              dist = FT_MulFix( dist, scale );
1495              if ( dist < best_dist )
1496              {
1497                best_dist = dist;
1498                best_blue = & blue->shoot;
1499              }
1500            }
1501          }
1502#endif
1503        }
1504      }
1505
1506      if ( best_blue )
1507        edge->blue_edge = best_blue;
1508    }
1509  }
1510
1511
1512  static FT_Error
1513  af_latin2_hints_init( AF_GlyphHints    hints,
1514                        AF_LatinMetrics  metrics )
1515  {
1516    FT_Render_Mode  mode;
1517    FT_UInt32       scaler_flags, other_flags;
1518    FT_Face         face = metrics->root.scaler.face;
1519
1520
1521    af_glyph_hints_rescale( hints, (AF_StyleMetrics)metrics );
1522
1523    /*
1524     *  correct x_scale and y_scale if needed, since they may have
1525     *  been modified `af_latin2_metrics_scale_dim' above
1526     */
1527    hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
1528    hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
1529    hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
1530    hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
1531
1532    /* compute flags depending on render mode, etc. */
1533    mode = metrics->root.scaler.render_mode;
1534
1535#if 0 /* #ifdef AF_CONFIG_OPTION_USE_WARPER */
1536    if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
1537      metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
1538#endif
1539
1540    scaler_flags = hints->scaler_flags;
1541    other_flags  = 0;
1542
1543    /*
1544     *  We snap the width of vertical stems for the monochrome and
1545     *  horizontal LCD rendering targets only.
1546     */
1547    if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
1548      other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
1549
1550    /*
1551     *  We snap the width of horizontal stems for the monochrome and
1552     *  vertical LCD rendering targets only.
1553     */
1554    if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
1555      other_flags |= AF_LATIN_HINTS_VERT_SNAP;
1556
1557    /*
1558     *  We adjust stems to full pixels only if we don't use the `light' mode.
1559     */
1560    if ( mode != FT_RENDER_MODE_LIGHT )
1561      other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
1562
1563    if ( mode == FT_RENDER_MODE_MONO )
1564      other_flags |= AF_LATIN_HINTS_MONO;
1565
1566    /*
1567     *  In `light' hinting mode we disable horizontal hinting completely.
1568     *  We also do it if the face is italic.
1569     */
1570    if ( mode == FT_RENDER_MODE_LIGHT                      ||
1571         ( face->style_flags & FT_STYLE_FLAG_ITALIC ) != 0 )
1572      scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL;
1573
1574#ifdef AF_CONFIG_OPTION_USE_WARPER
1575    /* get (global) warper flag */
1576    if ( !metrics->root.globals->module->warping )
1577      scaler_flags |= AF_SCALER_FLAG_NO_WARPER;
1578#endif
1579
1580    hints->scaler_flags = scaler_flags;
1581    hints->other_flags  = other_flags;
1582
1583    return 0;
1584  }
1585
1586
1587  /*************************************************************************/
1588  /*************************************************************************/
1589  /*****                                                               *****/
1590  /*****        L A T I N   G L Y P H   G R I D - F I T T I N G        *****/
1591  /*****                                                               *****/
1592  /*************************************************************************/
1593  /*************************************************************************/
1594
1595  /* snap a given width in scaled coordinates to one of the */
1596  /* current standard widths                                */
1597
1598  static FT_Pos
1599  af_latin2_snap_width( AF_Width  widths,
1600                        FT_UInt   count,
1601                        FT_Pos    width )
1602  {
1603    FT_UInt  n;
1604    FT_Pos   best      = 64 + 32 + 2;
1605    FT_Pos   reference = width;
1606    FT_Pos   scaled;
1607
1608
1609    for ( n = 0; n < count; n++ )
1610    {
1611      FT_Pos  w;
1612      FT_Pos  dist;
1613
1614
1615      w = widths[n].cur;
1616      dist = width - w;
1617      if ( dist < 0 )
1618        dist = -dist;
1619      if ( dist < best )
1620      {
1621        best      = dist;
1622        reference = w;
1623      }
1624    }
1625
1626    scaled = FT_PIX_ROUND( reference );
1627
1628    if ( width >= reference )
1629    {
1630      if ( width < scaled + 48 )
1631        width = reference;
1632    }
1633    else
1634    {
1635      if ( width > scaled - 48 )
1636        width = reference;
1637    }
1638
1639    return width;
1640  }
1641
1642
1643  /* compute the snapped width of a given stem */
1644
1645  static FT_Pos
1646  af_latin2_compute_stem_width( AF_GlyphHints  hints,
1647                                AF_Dimension   dim,
1648                                FT_Pos         width,
1649                                FT_UInt        base_flags,
1650                                FT_UInt        stem_flags )
1651  {
1652    AF_LatinMetrics  metrics  = (AF_LatinMetrics) hints->metrics;
1653    AF_LatinAxis     axis     = & metrics->axis[dim];
1654    FT_Pos           dist     = width;
1655    FT_Int           sign     = 0;
1656    FT_Int           vertical = ( dim == AF_DIMENSION_VERT );
1657
1658    FT_UNUSED( base_flags );
1659
1660
1661    if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ||
1662          axis->extra_light                      )
1663      return width;
1664
1665    if ( dist < 0 )
1666    {
1667      dist = -width;
1668      sign = 1;
1669    }
1670
1671    if ( (  vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
1672         ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
1673    {
1674      /* smooth hinting process: very lightly quantize the stem width */
1675
1676      /* leave the widths of serifs alone */
1677
1678      if ( ( stem_flags & AF_EDGE_SERIF ) && vertical && ( dist < 3 * 64 ) )
1679        goto Done_Width;
1680
1681#if 0
1682      else if ( ( base_flags & AF_EDGE_ROUND ) )
1683      {
1684        if ( dist < 80 )
1685          dist = 64;
1686      }
1687      else if ( dist < 56 )
1688        dist = 56;
1689#endif
1690      if ( axis->width_count > 0 )
1691      {
1692        FT_Pos  delta;
1693
1694
1695        /* compare to standard width */
1696        if ( axis->width_count > 0 )
1697        {
1698          delta = dist - axis->widths[0].cur;
1699
1700          if ( delta < 0 )
1701            delta = -delta;
1702
1703          if ( delta < 40 )
1704          {
1705            dist = axis->widths[0].cur;
1706            if ( dist < 48 )
1707              dist = 48;
1708
1709            goto Done_Width;
1710          }
1711        }
1712
1713        if ( dist < 3 * 64 )
1714        {
1715          delta  = dist & 63;
1716          dist  &= -64;
1717
1718          if ( delta < 10 )
1719            dist += delta;
1720
1721          else if ( delta < 32 )
1722            dist += 10;
1723
1724          else if ( delta < 54 )
1725            dist += 54;
1726
1727          else
1728            dist += delta;
1729        }
1730        else
1731          dist = ( dist + 32 ) & ~63;
1732      }
1733    }
1734    else
1735    {
1736      /* strong hinting process: snap the stem width to integer pixels */
1737      FT_Pos  org_dist = dist;
1738
1739
1740      dist = af_latin2_snap_width( axis->widths, axis->width_count, dist );
1741
1742      if ( vertical )
1743      {
1744        /* in the case of vertical hinting, always round */
1745        /* the stem heights to integer pixels            */
1746
1747        if ( dist >= 64 )
1748          dist = ( dist + 16 ) & ~63;
1749        else
1750          dist = 64;
1751      }
1752      else
1753      {
1754        if ( AF_LATIN_HINTS_DO_MONO( hints ) )
1755        {
1756          /* monochrome horizontal hinting: snap widths to integer pixels */
1757          /* with a different threshold                                   */
1758
1759          if ( dist < 64 )
1760            dist = 64;
1761          else
1762            dist = ( dist + 32 ) & ~63;
1763        }
1764        else
1765        {
1766          /* for horizontal anti-aliased hinting, we adopt a more subtle */
1767          /* approach: we strengthen small stems, round stems whose size */
1768          /* is between 1 and 2 pixels to an integer, otherwise nothing  */
1769
1770          if ( dist < 48 )
1771            dist = ( dist + 64 ) >> 1;
1772
1773          else if ( dist < 128 )
1774          {
1775            /* We only round to an integer width if the corresponding */
1776            /* distortion is less than 1/4 pixel.  Otherwise this     */
1777            /* makes everything worse since the diagonals, which are  */
1778            /* not hinted, appear a lot bolder or thinner than the    */
1779            /* vertical stems.                                        */
1780
1781            FT_Int  delta;
1782
1783
1784            dist = ( dist + 22 ) & ~63;
1785            delta = dist - org_dist;
1786            if ( delta < 0 )
1787              delta = -delta;
1788
1789            if ( delta >= 16 )
1790            {
1791              dist = org_dist;
1792              if ( dist < 48 )
1793                dist = ( dist + 64 ) >> 1;
1794            }
1795          }
1796          else
1797            /* round otherwise to prevent color fringes in LCD mode */
1798            dist = ( dist + 32 ) & ~63;
1799        }
1800      }
1801    }
1802
1803  Done_Width:
1804    if ( sign )
1805      dist = -dist;
1806
1807    return dist;
1808  }
1809
1810
1811  /* align one stem edge relative to the previous stem edge */
1812
1813  static void
1814  af_latin2_align_linked_edge( AF_GlyphHints  hints,
1815                               AF_Dimension   dim,
1816                               AF_Edge        base_edge,
1817                               AF_Edge        stem_edge )
1818  {
1819    FT_Pos  dist = stem_edge->opos - base_edge->opos;
1820
1821    FT_Pos  fitted_width = af_latin2_compute_stem_width( hints, dim, dist,
1822                                                         base_edge->flags,
1823                                                         stem_edge->flags );
1824
1825
1826    stem_edge->pos = base_edge->pos + fitted_width;
1827
1828    FT_TRACE5(( "LINK: edge %d (opos=%.2f) linked to (%.2f), "
1829                "dist was %.2f, now %.2f\n",
1830                stem_edge-hints->axis[dim].edges, stem_edge->opos / 64.0,
1831                stem_edge->pos / 64.0, dist / 64.0, fitted_width / 64.0 ));
1832  }
1833
1834
1835  static void
1836  af_latin2_align_serif_edge( AF_GlyphHints  hints,
1837                              AF_Edge        base,
1838                              AF_Edge        serif )
1839  {
1840    FT_UNUSED( hints );
1841
1842    serif->pos = base->pos + ( serif->opos - base->opos );
1843  }
1844
1845
1846  /*************************************************************************/
1847  /*************************************************************************/
1848  /*************************************************************************/
1849  /****                                                                 ****/
1850  /****                    E D G E   H I N T I N G                      ****/
1851  /****                                                                 ****/
1852  /*************************************************************************/
1853  /*************************************************************************/
1854  /*************************************************************************/
1855
1856
1857  static void
1858  af_latin2_hint_edges( AF_GlyphHints  hints,
1859                        AF_Dimension   dim )
1860  {
1861    AF_AxisHints  axis       = &hints->axis[dim];
1862    AF_Edge       edges      = axis->edges;
1863    AF_Edge       edge_limit = edges + axis->num_edges;
1864    AF_Edge       edge;
1865    AF_Edge       anchor     = NULL;
1866    FT_Int        has_serifs = 0;
1867    FT_Pos        anchor_drift = 0;
1868
1869
1870
1871    FT_TRACE5(( "==== hinting %s edges =====\n",
1872                dim == AF_DIMENSION_HORZ ? "vertical" : "horizontal" ));
1873
1874    /* we begin by aligning all stems relative to the blue zone */
1875    /* if needed -- that's only for horizontal edges            */
1876
1877    if ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_BLUES( hints ) )
1878    {
1879      for ( edge = edges; edge < edge_limit; edge++ )
1880      {
1881        AF_Width  blue;
1882        AF_Edge   edge1, edge2;
1883
1884
1885        if ( edge->flags & AF_EDGE_DONE )
1886          continue;
1887
1888        blue  = edge->blue_edge;
1889        edge1 = NULL;
1890        edge2 = edge->link;
1891
1892        if ( blue )
1893        {
1894          edge1 = edge;
1895        }
1896        else if ( edge2 && edge2->blue_edge )
1897        {
1898          blue  = edge2->blue_edge;
1899          edge1 = edge2;
1900          edge2 = edge;
1901        }
1902
1903        if ( !edge1 )
1904          continue;
1905
1906        FT_TRACE5(( "BLUE: edge %d (opos=%.2f) snapped to (%.2f), "
1907                    "was (%.2f)\n",
1908                    edge1-edges, edge1->opos / 64.0, blue->fit / 64.0,
1909                    edge1->pos / 64.0 ));
1910
1911        edge1->pos    = blue->fit;
1912        edge1->flags |= AF_EDGE_DONE;
1913
1914        if ( edge2 && !edge2->blue_edge )
1915        {
1916          af_latin2_align_linked_edge( hints, dim, edge1, edge2 );
1917          edge2->flags |= AF_EDGE_DONE;
1918        }
1919
1920        if ( !anchor )
1921        {
1922          anchor = edge;
1923
1924          anchor_drift = ( anchor->pos - anchor->opos );
1925          if ( edge2 )
1926            anchor_drift = ( anchor_drift +
1927                             ( edge2->pos - edge2->opos ) ) >> 1;
1928        }
1929      }
1930    }
1931
1932    /* now we will align all stem edges, trying to maintain the */
1933    /* relative order of stems in the glyph                     */
1934    for ( edge = edges; edge < edge_limit; edge++ )
1935    {
1936      AF_Edge  edge2;
1937
1938
1939      if ( edge->flags & AF_EDGE_DONE )
1940        continue;
1941
1942      /* skip all non-stem edges */
1943      edge2 = edge->link;
1944      if ( !edge2 )
1945      {
1946        has_serifs++;
1947        continue;
1948      }
1949
1950      /* now align the stem */
1951
1952      /* this should not happen, but it's better to be safe */
1953      if ( edge2->blue_edge )
1954      {
1955        FT_TRACE5(( "ASSERTION FAILED for edge %d\n", edge2-edges ));
1956
1957        af_latin2_align_linked_edge( hints, dim, edge2, edge );
1958        edge->flags |= AF_EDGE_DONE;
1959        continue;
1960      }
1961
1962      if ( !anchor )
1963      {
1964        FT_Pos  org_len, org_center, cur_len;
1965        FT_Pos  cur_pos1, error1, error2, u_off, d_off;
1966
1967
1968        org_len = edge2->opos - edge->opos;
1969        cur_len = af_latin2_compute_stem_width( hints, dim, org_len,
1970                                                edge->flags,
1971                                                edge2->flags );
1972        if ( cur_len <= 64 )
1973          u_off = d_off = 32;
1974        else
1975        {
1976          u_off = 38;
1977          d_off = 26;
1978        }
1979
1980        if ( cur_len < 96 )
1981        {
1982          org_center = edge->opos + ( org_len >> 1 );
1983
1984          cur_pos1   = FT_PIX_ROUND( org_center );
1985
1986          error1 = org_center - ( cur_pos1 - u_off );
1987          if ( error1 < 0 )
1988            error1 = -error1;
1989
1990          error2 = org_center - ( cur_pos1 + d_off );
1991          if ( error2 < 0 )
1992            error2 = -error2;
1993
1994          if ( error1 < error2 )
1995            cur_pos1 -= u_off;
1996          else
1997            cur_pos1 += d_off;
1998
1999          edge->pos  = cur_pos1 - cur_len / 2;
2000          edge2->pos = edge->pos + cur_len;
2001        }
2002        else
2003          edge->pos = FT_PIX_ROUND( edge->opos );
2004
2005        FT_TRACE5(( "ANCHOR: edge %d (opos=%.2f) and %d (opos=%.2f)"
2006                    " snapped to (%.2f) (%.2f)\n",
2007                    edge-edges, edge->opos / 64.0,
2008                    edge2-edges, edge2->opos / 64.0,
2009                    edge->pos / 64.0, edge2->pos / 64.0 ));
2010        anchor = edge;
2011
2012        edge->flags |= AF_EDGE_DONE;
2013
2014        af_latin2_align_linked_edge( hints, dim, edge, edge2 );
2015
2016        edge2->flags |= AF_EDGE_DONE;
2017
2018        anchor_drift = ( ( anchor->pos - anchor->opos ) +
2019                         ( edge2->pos - edge2->opos ) ) >> 1;
2020
2021        FT_TRACE5(( "DRIFT: %.2f\n", anchor_drift/64.0 ));
2022      }
2023      else
2024      {
2025        FT_Pos   org_pos, org_len, org_center, cur_center, cur_len;
2026        FT_Pos   org_left, org_right;
2027
2028
2029        org_pos    = edge->opos + anchor_drift;
2030        org_len    = edge2->opos - edge->opos;
2031        org_center = org_pos + ( org_len >> 1 );
2032
2033        cur_len = af_latin2_compute_stem_width( hints, dim, org_len,
2034                                                edge->flags,
2035                                                edge2->flags );
2036
2037        org_left  = org_pos + ( ( org_len - cur_len ) >> 1 );
2038        org_right = org_pos + ( ( org_len + cur_len ) >> 1 );
2039
2040        FT_TRACE5(( "ALIGN: left=%.2f right=%.2f ",
2041                    org_left / 64.0, org_right / 64.0 ));
2042        cur_center = org_center;
2043
2044        if ( edge2->flags & AF_EDGE_DONE )
2045        {
2046          FT_TRACE5(( "\n" ));
2047          edge->pos = edge2->pos - cur_len;
2048        }
2049        else
2050        {
2051         /* we want to compare several displacement, and choose
2052          * the one that increases fitness while minimizing
2053          * distortion as well
2054          */
2055          FT_Pos   displacements[6], scores[6], org, fit, delta;
2056          FT_UInt  count = 0;
2057
2058          /* note: don't even try to fit tiny stems */
2059          if ( cur_len < 32 )
2060          {
2061            FT_TRACE5(( "tiny stem\n" ));
2062            goto AlignStem;
2063          }
2064
2065          /* if the span is within a single pixel, don't touch it */
2066          if ( FT_PIX_FLOOR( org_left ) == FT_PIX_CEIL( org_right ) )
2067          {
2068            FT_TRACE5(( "single pixel stem\n" ));
2069            goto AlignStem;
2070          }
2071
2072          if ( cur_len <= 96 )
2073          {
2074           /* we want to avoid the absolute worst case which is
2075            * when the left and right edges of the span each represent
2076            * about 50% of the gray. we'd better want to change this
2077            * to 25/75%, since this is much more pleasant to the eye with
2078            * very acceptable distortion
2079            */
2080            FT_Pos  frac_left  = org_left  & 63;
2081            FT_Pos  frac_right = org_right & 63;
2082
2083            if ( frac_left  >= 22 && frac_left  <= 42 &&
2084                 frac_right >= 22 && frac_right <= 42 )
2085            {
2086              org = frac_left;
2087              fit = ( org <= 32 ) ? 16 : 48;
2088              delta = FT_ABS( fit - org );
2089              displacements[count] = fit - org;
2090              scores[count++]      = delta;
2091              FT_TRACE5(( "dispA=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2092
2093              org = frac_right;
2094              fit = ( org <= 32 ) ? 16 : 48;
2095              delta = FT_ABS( fit - org );
2096              displacements[count] = fit - org;
2097              scores[count++]     = delta;
2098              FT_TRACE5(( "dispB=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2099            }
2100          }
2101
2102          /* snapping the left edge to the grid */
2103          org   = org_left;
2104          fit   = FT_PIX_ROUND( org );
2105          delta = FT_ABS( fit - org );
2106          displacements[count] = fit - org;
2107          scores[count++]      = delta;
2108          FT_TRACE5(( "dispC=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2109
2110          /* snapping the right edge to the grid */
2111          org   = org_right;
2112          fit   = FT_PIX_ROUND( org );
2113          delta = FT_ABS( fit - org );
2114          displacements[count] = fit - org;
2115          scores[count++]      = delta;
2116          FT_TRACE5(( "dispD=%.2f (%d) ", ( fit - org ) / 64.0, delta ));
2117
2118          /* now find the best displacement */
2119          {
2120            FT_Pos  best_score = scores[0];
2121            FT_Pos  best_disp  = displacements[0];
2122            FT_UInt nn;
2123
2124            for ( nn = 1; nn < count; nn++ )
2125            {
2126              if ( scores[nn] < best_score )
2127              {
2128                best_score = scores[nn];
2129                best_disp  = displacements[nn];
2130              }
2131            }
2132
2133            cur_center = org_center + best_disp;
2134          }
2135          FT_TRACE5(( "\n" ));
2136        }
2137
2138      AlignStem:
2139        edge->pos  = cur_center - ( cur_len >> 1 );
2140        edge2->pos = edge->pos + cur_len;
2141
2142        FT_TRACE5(( "STEM1: %d (opos=%.2f) to %d (opos=%.2f)"
2143                    " snapped to (%.2f) and (%.2f),"
2144                    " org_len=%.2f cur_len=%.2f\n",
2145                    edge-edges, edge->opos / 64.0,
2146                    edge2-edges, edge2->opos / 64.0,
2147                    edge->pos / 64.0, edge2->pos / 64.0,
2148                    org_len / 64.0, cur_len / 64.0 ));
2149
2150        edge->flags  |= AF_EDGE_DONE;
2151        edge2->flags |= AF_EDGE_DONE;
2152
2153        if ( edge > edges && edge->pos < edge[-1].pos )
2154        {
2155          FT_TRACE5(( "BOUND: %d (pos=%.2f) to (%.2f)\n",
2156                      edge-edges, edge->pos / 64.0, edge[-1].pos / 64.0 ));
2157          edge->pos = edge[-1].pos;
2158        }
2159      }
2160    }
2161
2162    /* make sure that lowercase m's maintain their symmetry */
2163
2164    /* In general, lowercase m's have six vertical edges if they are sans */
2165    /* serif, or twelve if they are with serifs.  This implementation is  */
2166    /* based on that assumption, and seems to work very well with most    */
2167    /* faces.  However, if for a certain face this assumption is not      */
2168    /* true, the m is just rendered like before.  In addition, any stem   */
2169    /* correction will only be applied to symmetrical glyphs (even if the */
2170    /* glyph is not an m), so the potential for unwanted distortion is    */
2171    /* relatively low.                                                    */
2172
2173    /* We don't handle horizontal edges since we can't easily assure that */
2174    /* the third (lowest) stem aligns with the base line; it might end up */
2175    /* one pixel higher or lower.                                         */
2176
2177#if 0
2178    {
2179      FT_Int  n_edges = edge_limit - edges;
2180
2181
2182      if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
2183      {
2184        AF_Edge  edge1, edge2, edge3;
2185        FT_Pos   dist1, dist2, span, delta;
2186
2187
2188        if ( n_edges == 6 )
2189        {
2190          edge1 = edges;
2191          edge2 = edges + 2;
2192          edge3 = edges + 4;
2193        }
2194        else
2195        {
2196          edge1 = edges + 1;
2197          edge2 = edges + 5;
2198          edge3 = edges + 9;
2199        }
2200
2201        dist1 = edge2->opos - edge1->opos;
2202        dist2 = edge3->opos - edge2->opos;
2203
2204        span = dist1 - dist2;
2205        if ( span < 0 )
2206          span = -span;
2207
2208        if ( span < 8 )
2209        {
2210          delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
2211          edge3->pos -= delta;
2212          if ( edge3->link )
2213            edge3->link->pos -= delta;
2214
2215          /* move the serifs along with the stem */
2216          if ( n_edges == 12 )
2217          {
2218            ( edges + 8 )->pos -= delta;
2219            ( edges + 11 )->pos -= delta;
2220          }
2221
2222          edge3->flags |= AF_EDGE_DONE;
2223          if ( edge3->link )
2224            edge3->link->flags |= AF_EDGE_DONE;
2225        }
2226      }
2227    }
2228#endif
2229
2230    if ( has_serifs || !anchor )
2231    {
2232      /*
2233       *  now hint the remaining edges (serifs and single) in order
2234       *  to complete our processing
2235       */
2236      for ( edge = edges; edge < edge_limit; edge++ )
2237      {
2238        FT_Pos  delta;
2239
2240
2241        if ( edge->flags & AF_EDGE_DONE )
2242          continue;
2243
2244        delta = 1000;
2245
2246        if ( edge->serif )
2247        {
2248          delta = edge->serif->opos - edge->opos;
2249          if ( delta < 0 )
2250            delta = -delta;
2251        }
2252
2253        if ( delta < 64 + 16 )
2254        {
2255          af_latin2_align_serif_edge( hints, edge->serif, edge );
2256          FT_TRACE5(( "SERIF: edge %d (opos=%.2f) serif to %d (opos=%.2f)"
2257                      " aligned to (%.2f)\n",
2258                      edge-edges, edge->opos / 64.0,
2259                      edge->serif - edges, edge->serif->opos / 64.0,
2260                      edge->pos / 64.0 ));
2261        }
2262        else if ( !anchor )
2263        {
2264          FT_TRACE5(( "SERIF_ANCHOR: edge %d (opos=%.2f)"
2265                      " snapped to (%.2f)\n",
2266                      edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
2267          edge->pos = FT_PIX_ROUND( edge->opos );
2268          anchor    = edge;
2269        }
2270        else
2271        {
2272          AF_Edge  before, after;
2273
2274
2275          for ( before = edge - 1; before >= edges; before-- )
2276            if ( before->flags & AF_EDGE_DONE )
2277              break;
2278
2279          for ( after = edge + 1; after < edge_limit; after++ )
2280            if ( after->flags & AF_EDGE_DONE )
2281              break;
2282
2283          if ( before >= edges && before < edge   &&
2284               after < edge_limit && after > edge )
2285          {
2286            if ( after->opos == before->opos )
2287              edge->pos = before->pos;
2288            else
2289              edge->pos = before->pos +
2290                          FT_MulDiv( edge->opos - before->opos,
2291                                     after->pos - before->pos,
2292                                     after->opos - before->opos );
2293            FT_TRACE5(( "SERIF_LINK1: edge %d (opos=%.2f) snapped to (%.2f)"
2294                        " from %d (opos=%.2f)\n",
2295                        edge-edges, edge->opos / 64.0, edge->pos / 64.0,
2296                        before - edges, before->opos / 64.0 ));
2297          }
2298          else
2299          {
2300            edge->pos = anchor->pos +
2301                        ( ( edge->opos - anchor->opos + 16 ) & ~31 );
2302
2303            FT_TRACE5(( "SERIF_LINK2: edge %d (opos=%.2f)"
2304                        " snapped to (%.2f)\n",
2305                        edge-edges, edge->opos / 64.0, edge->pos / 64.0 ));
2306          }
2307        }
2308
2309        edge->flags |= AF_EDGE_DONE;
2310
2311        if ( edge > edges && edge->pos < edge[-1].pos )
2312          edge->pos = edge[-1].pos;
2313
2314        if ( edge + 1 < edge_limit        &&
2315             edge[1].flags & AF_EDGE_DONE &&
2316             edge->pos > edge[1].pos      )
2317          edge->pos = edge[1].pos;
2318      }
2319    }
2320  }
2321
2322
2323  static FT_Error
2324  af_latin2_hints_apply( FT_UInt          glyph_index,
2325                         AF_GlyphHints    hints,
2326                         FT_Outline*      outline,
2327                         AF_LatinMetrics  metrics )
2328  {
2329    FT_Error  error;
2330    int       dim;
2331
2332    FT_UNUSED( glyph_index );
2333
2334
2335    error = af_glyph_hints_reload( hints, outline );
2336    if ( error )
2337      goto Exit;
2338
2339    /* analyze glyph outline */
2340#ifdef AF_CONFIG_OPTION_USE_WARPER
2341    if ( ( metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT &&
2342           AF_HINTS_DO_WARP( hints )                                ) ||
2343         AF_HINTS_DO_HORIZONTAL( hints )                              )
2344#else
2345    if ( AF_HINTS_DO_HORIZONTAL( hints ) )
2346#endif
2347    {
2348      error = af_latin2_hints_detect_features( hints, AF_DIMENSION_HORZ );
2349      if ( error )
2350        goto Exit;
2351    }
2352
2353    if ( AF_HINTS_DO_VERTICAL( hints ) )
2354    {
2355      error = af_latin2_hints_detect_features( hints, AF_DIMENSION_VERT );
2356      if ( error )
2357        goto Exit;
2358
2359      af_latin2_hints_compute_blue_edges( hints, metrics );
2360    }
2361
2362    /* grid-fit the outline */
2363    for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
2364    {
2365#ifdef AF_CONFIG_OPTION_USE_WARPER
2366      if ( dim == AF_DIMENSION_HORZ                                 &&
2367           metrics->root.scaler.render_mode == FT_RENDER_MODE_LIGHT &&
2368           AF_HINTS_DO_WARP( hints )                                )
2369      {
2370        AF_WarperRec  warper;
2371        FT_Fixed      scale;
2372        FT_Pos        delta;
2373
2374
2375        af_warper_compute( &warper, hints, dim, &scale, &delta );
2376        af_glyph_hints_scale_dim( hints, dim, scale, delta );
2377        continue;
2378      }
2379#endif /* AF_CONFIG_OPTION_USE_WARPER */
2380
2381      if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
2382           ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) )   )
2383      {
2384        af_latin2_hint_edges( hints, (AF_Dimension)dim );
2385        af_glyph_hints_align_edge_points( hints, (AF_Dimension)dim );
2386        af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
2387        af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
2388      }
2389    }
2390    af_glyph_hints_save( hints, outline );
2391
2392  Exit:
2393    return error;
2394  }
2395
2396
2397  /*************************************************************************/
2398  /*************************************************************************/
2399  /*****                                                               *****/
2400  /*****              L A T I N   S C R I P T   C L A S S              *****/
2401  /*****                                                               *****/
2402  /*************************************************************************/
2403  /*************************************************************************/
2404
2405
2406  AF_DEFINE_WRITING_SYSTEM_CLASS(
2407    af_latin2_writing_system_class,
2408
2409    AF_WRITING_SYSTEM_LATIN2,
2410
2411    sizeof ( AF_LatinMetricsRec ),
2412
2413    (AF_WritingSystem_InitMetricsFunc) af_latin2_metrics_init,
2414    (AF_WritingSystem_ScaleMetricsFunc)af_latin2_metrics_scale,
2415    (AF_WritingSystem_DoneMetricsFunc) NULL,
2416    (AF_WritingSystem_GetStdWidthsFunc)af_latin2_get_standard_widths,
2417
2418    (AF_WritingSystem_InitHintsFunc)   af_latin2_hints_init,
2419    (AF_WritingSystem_ApplyHintsFunc)  af_latin2_hints_apply
2420  )
2421
2422
2423/* END */
2424