1/***************************************************************************/
2/*                                                                         */
3/*  pshalgo.c                                                              */
4/*                                                                         */
5/*    PostScript hinting algorithm (body).                                 */
6/*                                                                         */
7/*  Copyright 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010   */
8/*            by                                                           */
9/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
10/*                                                                         */
11/*  This file is part of the FreeType project, and may only be used        */
12/*  modified and distributed under the terms of the FreeType project       */
13/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
14/*  this file you indicate that you have read the license and              */
15/*  understand and accept it fully.                                        */
16/*                                                                         */
17/***************************************************************************/
18
19
20#include <ft2build.h>
21#include FT_INTERNAL_OBJECTS_H
22#include FT_INTERNAL_DEBUG_H
23#include FT_INTERNAL_CALC_H
24#include "pshalgo.h"
25
26#include "pshnterr.h"
27
28
29#undef  FT_COMPONENT
30#define FT_COMPONENT  trace_pshalgo2
31
32
33#ifdef DEBUG_HINTER
34  PSH_Hint_Table  ps_debug_hint_table = 0;
35  PSH_HintFunc    ps_debug_hint_func  = 0;
36  PSH_Glyph       ps_debug_glyph      = 0;
37#endif
38
39
40#define  COMPUTE_INFLEXS  /* compute inflection points to optimize `S' */
41                          /* and similar glyphs                        */
42#define  STRONGER         /* slightly increase the contrast of smooth  */
43                          /* hinting                                   */
44
45
46  /*************************************************************************/
47  /*************************************************************************/
48  /*****                                                               *****/
49  /*****                  BASIC HINTS RECORDINGS                       *****/
50  /*****                                                               *****/
51  /*************************************************************************/
52  /*************************************************************************/
53
54  /* return true if two stem hints overlap */
55  static FT_Int
56  psh_hint_overlap( PSH_Hint  hint1,
57                    PSH_Hint  hint2 )
58  {
59    return hint1->org_pos + hint1->org_len >= hint2->org_pos &&
60           hint2->org_pos + hint2->org_len >= hint1->org_pos;
61  }
62
63
64  /* destroy hints table */
65  static void
66  psh_hint_table_done( PSH_Hint_Table  table,
67                       FT_Memory       memory )
68  {
69    FT_FREE( table->zones );
70    table->num_zones = 0;
71    table->zone      = 0;
72
73    FT_FREE( table->sort );
74    FT_FREE( table->hints );
75    table->num_hints   = 0;
76    table->max_hints   = 0;
77    table->sort_global = 0;
78  }
79
80
81  /* deactivate all hints in a table */
82  static void
83  psh_hint_table_deactivate( PSH_Hint_Table  table )
84  {
85    FT_UInt   count = table->max_hints;
86    PSH_Hint  hint  = table->hints;
87
88
89    for ( ; count > 0; count--, hint++ )
90    {
91      psh_hint_deactivate( hint );
92      hint->order = -1;
93    }
94  }
95
96
97  /* internal function to record a new hint */
98  static void
99  psh_hint_table_record( PSH_Hint_Table  table,
100                         FT_UInt         idx )
101  {
102    PSH_Hint  hint = table->hints + idx;
103
104
105    if ( idx >= table->max_hints )
106    {
107      FT_TRACE0(( "psh_hint_table_record: invalid hint index %d\n", idx ));
108      return;
109    }
110
111    /* ignore active hints */
112    if ( psh_hint_is_active( hint ) )
113      return;
114
115    psh_hint_activate( hint );
116
117    /* now scan the current active hint set to check */
118    /* whether `hint' overlaps with another hint     */
119    {
120      PSH_Hint*  sorted = table->sort_global;
121      FT_UInt    count  = table->num_hints;
122      PSH_Hint   hint2;
123
124
125      hint->parent = 0;
126      for ( ; count > 0; count--, sorted++ )
127      {
128        hint2 = sorted[0];
129
130        if ( psh_hint_overlap( hint, hint2 ) )
131        {
132          hint->parent = hint2;
133          break;
134        }
135      }
136    }
137
138    if ( table->num_hints < table->max_hints )
139      table->sort_global[table->num_hints++] = hint;
140    else
141      FT_TRACE0(( "psh_hint_table_record: too many sorted hints!  BUG!\n" ));
142  }
143
144
145  static void
146  psh_hint_table_record_mask( PSH_Hint_Table  table,
147                              PS_Mask         hint_mask )
148  {
149    FT_Int    mask = 0, val = 0;
150    FT_Byte*  cursor = hint_mask->bytes;
151    FT_UInt   idx, limit;
152
153
154    limit = hint_mask->num_bits;
155
156    for ( idx = 0; idx < limit; idx++ )
157    {
158      if ( mask == 0 )
159      {
160        val  = *cursor++;
161        mask = 0x80;
162      }
163
164      if ( val & mask )
165        psh_hint_table_record( table, idx );
166
167      mask >>= 1;
168    }
169  }
170
171
172  /* create hints table */
173  static FT_Error
174  psh_hint_table_init( PSH_Hint_Table  table,
175                       PS_Hint_Table   hints,
176                       PS_Mask_Table   hint_masks,
177                       PS_Mask_Table   counter_masks,
178                       FT_Memory       memory )
179  {
180    FT_UInt   count;
181    FT_Error  error;
182
183    FT_UNUSED( counter_masks );
184
185
186    count = hints->num_hints;
187
188    /* allocate our tables */
189    if ( FT_NEW_ARRAY( table->sort,  2 * count     ) ||
190         FT_NEW_ARRAY( table->hints,     count     ) ||
191         FT_NEW_ARRAY( table->zones, 2 * count + 1 ) )
192      goto Exit;
193
194    table->max_hints   = count;
195    table->sort_global = table->sort + count;
196    table->num_hints   = 0;
197    table->num_zones   = 0;
198    table->zone        = 0;
199
200    /* initialize the `table->hints' array */
201    {
202      PSH_Hint  write = table->hints;
203      PS_Hint   read  = hints->hints;
204
205
206      for ( ; count > 0; count--, write++, read++ )
207      {
208        write->org_pos = read->pos;
209        write->org_len = read->len;
210        write->flags   = read->flags;
211      }
212    }
213
214    /* we now need to determine the initial `parent' stems; first  */
215    /* activate the hints that are given by the initial hint masks */
216    if ( hint_masks )
217    {
218      PS_Mask  mask = hint_masks->masks;
219
220
221      count             = hint_masks->num_masks;
222      table->hint_masks = hint_masks;
223
224      for ( ; count > 0; count--, mask++ )
225        psh_hint_table_record_mask( table, mask );
226    }
227
228    /* finally, do a linear parse in case some hints were left alone */
229    if ( table->num_hints != table->max_hints )
230    {
231      FT_UInt  idx;
232
233
234      FT_TRACE0(( "psh_hint_table_init: missing/incorrect hint masks\n" ));
235
236      count = table->max_hints;
237      for ( idx = 0; idx < count; idx++ )
238        psh_hint_table_record( table, idx );
239    }
240
241  Exit:
242    return error;
243  }
244
245
246  static void
247  psh_hint_table_activate_mask( PSH_Hint_Table  table,
248                                PS_Mask         hint_mask )
249  {
250    FT_Int    mask = 0, val = 0;
251    FT_Byte*  cursor = hint_mask->bytes;
252    FT_UInt   idx, limit, count;
253
254
255    limit = hint_mask->num_bits;
256    count = 0;
257
258    psh_hint_table_deactivate( table );
259
260    for ( idx = 0; idx < limit; idx++ )
261    {
262      if ( mask == 0 )
263      {
264        val  = *cursor++;
265        mask = 0x80;
266      }
267
268      if ( val & mask )
269      {
270        PSH_Hint  hint = &table->hints[idx];
271
272
273        if ( !psh_hint_is_active( hint ) )
274        {
275          FT_UInt     count2;
276
277#if 0
278          PSH_Hint*  sort = table->sort;
279          PSH_Hint   hint2;
280
281
282          for ( count2 = count; count2 > 0; count2--, sort++ )
283          {
284            hint2 = sort[0];
285            if ( psh_hint_overlap( hint, hint2 ) )
286              FT_TRACE0(( "psh_hint_table_activate_mask:"
287                          " found overlapping hints\n" ))
288          }
289#else
290          count2 = 0;
291#endif
292
293          if ( count2 == 0 )
294          {
295            psh_hint_activate( hint );
296            if ( count < table->max_hints )
297              table->sort[count++] = hint;
298            else
299              FT_TRACE0(( "psh_hint_tableactivate_mask:"
300                          " too many active hints\n" ));
301          }
302        }
303      }
304
305      mask >>= 1;
306    }
307    table->num_hints = count;
308
309    /* now, sort the hints; they are guaranteed to not overlap */
310    /* so we can compare their "org_pos" field directly        */
311    {
312      FT_Int     i1, i2;
313      PSH_Hint   hint1, hint2;
314      PSH_Hint*  sort = table->sort;
315
316
317      /* a simple bubble sort will do, since in 99% of cases, the hints */
318      /* will be already sorted -- and the sort will be linear          */
319      for ( i1 = 1; i1 < (FT_Int)count; i1++ )
320      {
321        hint1 = sort[i1];
322        for ( i2 = i1 - 1; i2 >= 0; i2-- )
323        {
324          hint2 = sort[i2];
325
326          if ( hint2->org_pos < hint1->org_pos )
327            break;
328
329          sort[i2 + 1] = hint2;
330          sort[i2]     = hint1;
331        }
332      }
333    }
334  }
335
336
337  /*************************************************************************/
338  /*************************************************************************/
339  /*****                                                               *****/
340  /*****               HINTS GRID-FITTING AND OPTIMIZATION             *****/
341  /*****                                                               *****/
342  /*************************************************************************/
343  /*************************************************************************/
344
345#if 1
346  static FT_Pos
347  psh_dimension_quantize_len( PSH_Dimension  dim,
348                              FT_Pos         len,
349                              FT_Bool        do_snapping )
350  {
351    if ( len <= 64 )
352      len = 64;
353    else
354    {
355      FT_Pos  delta = len - dim->stdw.widths[0].cur;
356
357
358      if ( delta < 0 )
359        delta = -delta;
360
361      if ( delta < 40 )
362      {
363        len = dim->stdw.widths[0].cur;
364        if ( len < 48 )
365          len = 48;
366      }
367
368      if ( len < 3 * 64 )
369      {
370        delta = ( len & 63 );
371        len  &= -64;
372
373        if ( delta < 10 )
374          len += delta;
375
376        else if ( delta < 32 )
377          len += 10;
378
379        else if ( delta < 54 )
380          len += 54;
381
382        else
383          len += delta;
384      }
385      else
386        len = FT_PIX_ROUND( len );
387    }
388
389    if ( do_snapping )
390      len = FT_PIX_ROUND( len );
391
392    return  len;
393  }
394#endif /* 0 */
395
396
397#ifdef DEBUG_HINTER
398
399  static void
400  ps_simple_scale( PSH_Hint_Table  table,
401                   FT_Fixed        scale,
402                   FT_Fixed        delta,
403                   FT_Int          dimension )
404  {
405    PSH_Hint  hint;
406    FT_UInt   count;
407
408
409    for ( count = 0; count < table->max_hints; count++ )
410    {
411      hint = table->hints + count;
412
413      hint->cur_pos = FT_MulFix( hint->org_pos, scale ) + delta;
414      hint->cur_len = FT_MulFix( hint->org_len, scale );
415
416      if ( ps_debug_hint_func )
417        ps_debug_hint_func( hint, dimension );
418    }
419  }
420
421#endif /* DEBUG_HINTER */
422
423
424  static FT_Fixed
425  psh_hint_snap_stem_side_delta( FT_Fixed  pos,
426                                 FT_Fixed  len )
427  {
428    FT_Fixed  delta1 = FT_PIX_ROUND( pos ) - pos;
429    FT_Fixed  delta2 = FT_PIX_ROUND( pos + len ) - pos - len;
430
431
432    if ( FT_ABS( delta1 ) <= FT_ABS( delta2 ) )
433      return delta1;
434    else
435      return delta2;
436  }
437
438
439  static void
440  psh_hint_align( PSH_Hint     hint,
441                  PSH_Globals  globals,
442                  FT_Int       dimension,
443                  PSH_Glyph    glyph )
444  {
445    PSH_Dimension  dim   = &globals->dimension[dimension];
446    FT_Fixed       scale = dim->scale_mult;
447    FT_Fixed       delta = dim->scale_delta;
448
449
450    if ( !psh_hint_is_fitted( hint ) )
451    {
452      FT_Pos  pos = FT_MulFix( hint->org_pos, scale ) + delta;
453      FT_Pos  len = FT_MulFix( hint->org_len, scale );
454
455      FT_Int            do_snapping;
456      FT_Pos            fit_len;
457      PSH_AlignmentRec  align;
458
459
460      /* ignore stem alignments when requested through the hint flags */
461      if ( ( dimension == 0 && !glyph->do_horz_hints ) ||
462           ( dimension == 1 && !glyph->do_vert_hints ) )
463      {
464        hint->cur_pos = pos;
465        hint->cur_len = len;
466
467        psh_hint_set_fitted( hint );
468        return;
469      }
470
471      /* perform stem snapping when requested - this is necessary
472       * for monochrome and LCD hinting modes only
473       */
474      do_snapping = ( dimension == 0 && glyph->do_horz_snapping ) ||
475                    ( dimension == 1 && glyph->do_vert_snapping );
476
477      hint->cur_len = fit_len = len;
478
479      /* check blue zones for horizontal stems */
480      align.align     = PSH_BLUE_ALIGN_NONE;
481      align.align_bot = align.align_top = 0;
482
483      if ( dimension == 1 )
484        psh_blues_snap_stem( &globals->blues,
485                             hint->org_pos + hint->org_len,
486                             hint->org_pos,
487                             &align );
488
489      switch ( align.align )
490      {
491      case PSH_BLUE_ALIGN_TOP:
492        /* the top of the stem is aligned against a blue zone */
493        hint->cur_pos = align.align_top - fit_len;
494        break;
495
496      case PSH_BLUE_ALIGN_BOT:
497        /* the bottom of the stem is aligned against a blue zone */
498        hint->cur_pos = align.align_bot;
499        break;
500
501      case PSH_BLUE_ALIGN_TOP | PSH_BLUE_ALIGN_BOT:
502        /* both edges of the stem are aligned against blue zones */
503        hint->cur_pos = align.align_bot;
504        hint->cur_len = align.align_top - align.align_bot;
505        break;
506
507      default:
508        {
509          PSH_Hint  parent = hint->parent;
510
511
512          if ( parent )
513          {
514            FT_Pos  par_org_center, par_cur_center;
515            FT_Pos  cur_org_center, cur_delta;
516
517
518            /* ensure that parent is already fitted */
519            if ( !psh_hint_is_fitted( parent ) )
520              psh_hint_align( parent, globals, dimension, glyph );
521
522            /* keep original relation between hints, this is, use the */
523            /* scaled distance between the centers of the hints to    */
524            /* compute the new position                               */
525            par_org_center = parent->org_pos + ( parent->org_len >> 1 );
526            par_cur_center = parent->cur_pos + ( parent->cur_len >> 1 );
527            cur_org_center = hint->org_pos   + ( hint->org_len   >> 1 );
528
529            cur_delta = FT_MulFix( cur_org_center - par_org_center, scale );
530            pos       = par_cur_center + cur_delta - ( len >> 1 );
531          }
532
533          hint->cur_pos = pos;
534          hint->cur_len = fit_len;
535
536          /* Stem adjustment tries to snap stem widths to standard
537           * ones.  This is important to prevent unpleasant rounding
538           * artefacts.
539           */
540          if ( glyph->do_stem_adjust )
541          {
542            if ( len <= 64 )
543            {
544              /* the stem is less than one pixel; we will center it
545               * around the nearest pixel center
546               */
547              if ( len >= 32 )
548              {
549                /* This is a special case where we also widen the stem
550                 * and align it to the pixel grid.
551                 *
552                 *   stem_center          = pos + (len/2)
553                 *   nearest_pixel_center = FT_ROUND(stem_center-32)+32
554                 *   new_pos              = nearest_pixel_center-32
555                 *                        = FT_ROUND(stem_center-32)
556                 *                        = FT_FLOOR(stem_center-32+32)
557                 *                        = FT_FLOOR(stem_center)
558                 *   new_len              = 64
559                 */
560                pos = FT_PIX_FLOOR( pos + ( len >> 1 ) );
561                len = 64;
562              }
563              else if ( len > 0 )
564              {
565                /* This is a very small stem; we simply align it to the
566                 * pixel grid, trying to find the minimal displacement.
567                 *
568                 * left               = pos
569                 * right              = pos + len
570                 * left_nearest_edge  = ROUND(pos)
571                 * right_nearest_edge = ROUND(right)
572                 *
573                 * if ( ABS(left_nearest_edge - left) <=
574                 *      ABS(right_nearest_edge - right) )
575                 *    new_pos = left
576                 * else
577                 *    new_pos = right
578                 */
579                FT_Pos  left_nearest  = FT_PIX_ROUND( pos );
580                FT_Pos  right_nearest = FT_PIX_ROUND( pos + len );
581                FT_Pos  left_disp     = left_nearest - pos;
582                FT_Pos  right_disp    = right_nearest - ( pos + len );
583
584
585                if ( left_disp < 0 )
586                  left_disp = -left_disp;
587                if ( right_disp < 0 )
588                  right_disp = -right_disp;
589                if ( left_disp <= right_disp )
590                  pos = left_nearest;
591                else
592                  pos = right_nearest;
593              }
594              else
595              {
596                /* this is a ghost stem; we simply round it */
597                pos = FT_PIX_ROUND( pos );
598              }
599            }
600            else
601            {
602              len = psh_dimension_quantize_len( dim, len, 0 );
603            }
604          }
605
606          /* now that we have a good hinted stem width, try to position */
607          /* the stem along a pixel grid integer coordinate             */
608          hint->cur_pos = pos + psh_hint_snap_stem_side_delta( pos, len );
609          hint->cur_len = len;
610        }
611      }
612
613      if ( do_snapping )
614      {
615        pos = hint->cur_pos;
616        len = hint->cur_len;
617
618        if ( len < 64 )
619          len = 64;
620        else
621          len = FT_PIX_ROUND( len );
622
623        switch ( align.align )
624        {
625          case PSH_BLUE_ALIGN_TOP:
626            hint->cur_pos = align.align_top - len;
627            hint->cur_len = len;
628            break;
629
630          case PSH_BLUE_ALIGN_BOT:
631            hint->cur_len = len;
632            break;
633
634          case PSH_BLUE_ALIGN_BOT | PSH_BLUE_ALIGN_TOP:
635            /* don't touch */
636            break;
637
638
639          default:
640            hint->cur_len = len;
641            if ( len & 64 )
642              pos = FT_PIX_FLOOR( pos + ( len >> 1 ) ) + 32;
643            else
644              pos = FT_PIX_ROUND( pos + ( len >> 1 ) );
645
646            hint->cur_pos = pos - ( len >> 1 );
647            hint->cur_len = len;
648        }
649      }
650
651      psh_hint_set_fitted( hint );
652
653#ifdef DEBUG_HINTER
654      if ( ps_debug_hint_func )
655        ps_debug_hint_func( hint, dimension );
656#endif
657    }
658  }
659
660
661#if 0  /* not used for now, experimental */
662
663 /*
664  *  A variant to perform "light" hinting (i.e. FT_RENDER_MODE_LIGHT)
665  *  of stems
666  */
667  static void
668  psh_hint_align_light( PSH_Hint     hint,
669                        PSH_Globals  globals,
670                        FT_Int       dimension,
671                        PSH_Glyph    glyph )
672  {
673    PSH_Dimension  dim   = &globals->dimension[dimension];
674    FT_Fixed       scale = dim->scale_mult;
675    FT_Fixed       delta = dim->scale_delta;
676
677
678    if ( !psh_hint_is_fitted( hint ) )
679    {
680      FT_Pos  pos = FT_MulFix( hint->org_pos, scale ) + delta;
681      FT_Pos  len = FT_MulFix( hint->org_len, scale );
682
683      FT_Pos  fit_len;
684
685      PSH_AlignmentRec  align;
686
687
688      /* ignore stem alignments when requested through the hint flags */
689      if ( ( dimension == 0 && !glyph->do_horz_hints ) ||
690           ( dimension == 1 && !glyph->do_vert_hints ) )
691      {
692        hint->cur_pos = pos;
693        hint->cur_len = len;
694
695        psh_hint_set_fitted( hint );
696        return;
697      }
698
699      fit_len = len;
700
701      hint->cur_len = fit_len;
702
703      /* check blue zones for horizontal stems */
704      align.align = PSH_BLUE_ALIGN_NONE;
705      align.align_bot = align.align_top = 0;
706
707      if ( dimension == 1 )
708        psh_blues_snap_stem( &globals->blues,
709                             hint->org_pos + hint->org_len,
710                             hint->org_pos,
711                             &align );
712
713      switch ( align.align )
714      {
715      case PSH_BLUE_ALIGN_TOP:
716        /* the top of the stem is aligned against a blue zone */
717        hint->cur_pos = align.align_top - fit_len;
718        break;
719
720      case PSH_BLUE_ALIGN_BOT:
721        /* the bottom of the stem is aligned against a blue zone */
722        hint->cur_pos = align.align_bot;
723        break;
724
725      case PSH_BLUE_ALIGN_TOP | PSH_BLUE_ALIGN_BOT:
726        /* both edges of the stem are aligned against blue zones */
727        hint->cur_pos = align.align_bot;
728        hint->cur_len = align.align_top - align.align_bot;
729        break;
730
731      default:
732        {
733          PSH_Hint  parent = hint->parent;
734
735
736          if ( parent )
737          {
738            FT_Pos  par_org_center, par_cur_center;
739            FT_Pos  cur_org_center, cur_delta;
740
741
742            /* ensure that parent is already fitted */
743            if ( !psh_hint_is_fitted( parent ) )
744              psh_hint_align_light( parent, globals, dimension, glyph );
745
746            par_org_center = parent->org_pos + ( parent->org_len / 2 );
747            par_cur_center = parent->cur_pos + ( parent->cur_len / 2 );
748            cur_org_center = hint->org_pos   + ( hint->org_len   / 2 );
749
750            cur_delta = FT_MulFix( cur_org_center - par_org_center, scale );
751            pos       = par_cur_center + cur_delta - ( len >> 1 );
752          }
753
754          /* Stems less than one pixel wide are easy -- we want to
755           * make them as dark as possible, so they must fall within
756           * one pixel.  If the stem is split between two pixels
757           * then snap the edge that is nearer to the pixel boundary
758           * to the pixel boundary.
759           */
760          if ( len <= 64 )
761          {
762            if ( ( pos + len + 63 ) / 64  != pos / 64 + 1 )
763              pos += psh_hint_snap_stem_side_delta ( pos, len );
764          }
765
766          /* Position stems other to minimize the amount of mid-grays.
767           * There are, in general, two positions that do this,
768           * illustrated as A) and B) below.
769           *
770           *   +                   +                   +                   +
771           *
772           * A)             |--------------------------------|
773           * B)   |--------------------------------|
774           * C)       |--------------------------------|
775           *
776           * Position A) (split the excess stem equally) should be better
777           * for stems of width N + f where f < 0.5.
778           *
779           * Position B) (split the deficiency equally) should be better
780           * for stems of width N + f where f > 0.5.
781           *
782           * It turns out though that minimizing the total number of lit
783           * pixels is also important, so position C), with one edge
784           * aligned with a pixel boundary is actually preferable
785           * to A).  There are also more possibile positions for C) than
786           * for A) or B), so it involves less distortion of the overall
787           * character shape.
788           */
789          else /* len > 64 */
790          {
791            FT_Fixed  frac_len = len & 63;
792            FT_Fixed  center = pos + ( len >> 1 );
793            FT_Fixed  delta_a, delta_b;
794
795
796            if ( ( len / 64 ) & 1 )
797            {
798              delta_a = FT_PIX_FLOOR( center ) + 32 - center;
799              delta_b = FT_PIX_ROUND( center ) - center;
800            }
801            else
802            {
803              delta_a = FT_PIX_ROUND( center ) - center;
804              delta_b = FT_PIX_FLOOR( center ) + 32 - center;
805            }
806
807            /* We choose between B) and C) above based on the amount
808             * of fractinal stem width; for small amounts, choose
809             * C) always, for large amounts, B) always, and inbetween,
810             * pick whichever one involves less stem movement.
811             */
812            if ( frac_len < 32 )
813            {
814              pos += psh_hint_snap_stem_side_delta ( pos, len );
815            }
816            else if ( frac_len < 48 )
817            {
818              FT_Fixed  side_delta = psh_hint_snap_stem_side_delta ( pos,
819                                                                     len );
820
821              if ( FT_ABS( side_delta ) < FT_ABS( delta_b ) )
822                pos += side_delta;
823              else
824                pos += delta_b;
825            }
826            else
827            {
828              pos += delta_b;
829            }
830          }
831
832          hint->cur_pos = pos;
833        }
834      }  /* switch */
835
836      psh_hint_set_fitted( hint );
837
838#ifdef DEBUG_HINTER
839      if ( ps_debug_hint_func )
840        ps_debug_hint_func( hint, dimension );
841#endif
842    }
843  }
844
845#endif /* 0 */
846
847
848  static void
849  psh_hint_table_align_hints( PSH_Hint_Table  table,
850                              PSH_Globals     globals,
851                              FT_Int          dimension,
852                              PSH_Glyph       glyph )
853  {
854    PSH_Hint       hint;
855    FT_UInt        count;
856
857#ifdef DEBUG_HINTER
858
859    PSH_Dimension  dim   = &globals->dimension[dimension];
860    FT_Fixed       scale = dim->scale_mult;
861    FT_Fixed       delta = dim->scale_delta;
862
863
864    if ( ps_debug_no_vert_hints && dimension == 0 )
865    {
866      ps_simple_scale( table, scale, delta, dimension );
867      return;
868    }
869
870    if ( ps_debug_no_horz_hints && dimension == 1 )
871    {
872      ps_simple_scale( table, scale, delta, dimension );
873      return;
874    }
875
876#endif /* DEBUG_HINTER*/
877
878    hint  = table->hints;
879    count = table->max_hints;
880
881    for ( ; count > 0; count--, hint++ )
882      psh_hint_align( hint, globals, dimension, glyph );
883  }
884
885
886  /*************************************************************************/
887  /*************************************************************************/
888  /*****                                                               *****/
889  /*****                POINTS INTERPOLATION ROUTINES                  *****/
890  /*****                                                               *****/
891  /*************************************************************************/
892  /*************************************************************************/
893
894#define PSH_ZONE_MIN  -3200000L
895#define PSH_ZONE_MAX  +3200000L
896
897#define xxDEBUG_ZONES
898
899
900#ifdef DEBUG_ZONES
901
902#include FT_CONFIG_STANDARD_LIBRARY_H
903
904  static void
905  psh_print_zone( PSH_Zone  zone )
906  {
907    printf( "zone [scale,delta,min,max] = [%.3f,%.3f,%d,%d]\n",
908             zone->scale / 65536.0,
909             zone->delta / 64.0,
910             zone->min,
911             zone->max );
912  }
913
914#else
915
916#define psh_print_zone( x )  do { } while ( 0 )
917
918#endif /* DEBUG_ZONES */
919
920
921  /*************************************************************************/
922  /*************************************************************************/
923  /*****                                                               *****/
924  /*****                    HINTER GLYPH MANAGEMENT                    *****/
925  /*****                                                               *****/
926  /*************************************************************************/
927  /*************************************************************************/
928
929#if 1
930
931#define  psh_corner_is_flat      ft_corner_is_flat
932#define  psh_corner_orientation  ft_corner_orientation
933
934#else
935
936  FT_LOCAL_DEF( FT_Int )
937  psh_corner_is_flat( FT_Pos  x_in,
938                      FT_Pos  y_in,
939                      FT_Pos  x_out,
940                      FT_Pos  y_out )
941  {
942    FT_Pos  ax = x_in;
943    FT_Pos  ay = y_in;
944
945    FT_Pos  d_in, d_out, d_corner;
946
947
948    if ( ax < 0 )
949      ax = -ax;
950    if ( ay < 0 )
951      ay = -ay;
952    d_in = ax + ay;
953
954    ax = x_out;
955    if ( ax < 0 )
956      ax = -ax;
957    ay = y_out;
958    if ( ay < 0 )
959      ay = -ay;
960    d_out = ax + ay;
961
962    ax = x_out + x_in;
963    if ( ax < 0 )
964      ax = -ax;
965    ay = y_out + y_in;
966    if ( ay < 0 )
967      ay = -ay;
968    d_corner = ax + ay;
969
970    return ( d_in + d_out - d_corner ) < ( d_corner >> 4 );
971  }
972
973  static FT_Int
974  psh_corner_orientation( FT_Pos  in_x,
975                          FT_Pos  in_y,
976                          FT_Pos  out_x,
977                          FT_Pos  out_y )
978  {
979    FT_Int  result;
980
981
982    /* deal with the trivial cases quickly */
983    if ( in_y == 0 )
984    {
985      if ( in_x >= 0 )
986        result = out_y;
987      else
988        result = -out_y;
989    }
990    else if ( in_x == 0 )
991    {
992      if ( in_y >= 0 )
993        result = -out_x;
994      else
995        result = out_x;
996    }
997    else if ( out_y == 0 )
998    {
999      if ( out_x >= 0 )
1000        result = in_y;
1001      else
1002        result = -in_y;
1003    }
1004    else if ( out_x == 0 )
1005    {
1006      if ( out_y >= 0 )
1007        result = -in_x;
1008      else
1009        result =  in_x;
1010    }
1011    else /* general case */
1012    {
1013      long long  delta = (long long)in_x * out_y - (long long)in_y * out_x;
1014
1015      if ( delta == 0 )
1016        result = 0;
1017      else
1018        result = 1 - 2 * ( delta < 0 );
1019    }
1020
1021    return result;
1022  }
1023
1024#endif /* !1 */
1025
1026
1027#ifdef COMPUTE_INFLEXS
1028
1029  /* compute all inflex points in a given glyph */
1030  static void
1031  psh_glyph_compute_inflections( PSH_Glyph  glyph )
1032  {
1033    FT_UInt  n;
1034
1035
1036    for ( n = 0; n < glyph->num_contours; n++ )
1037    {
1038      PSH_Point  first, start, end, before, after;
1039      FT_Pos     in_x, in_y, out_x, out_y;
1040      FT_Int     orient_prev, orient_cur;
1041      FT_Int     finished = 0;
1042
1043
1044      /* we need at least 4 points to create an inflection point */
1045      if ( glyph->contours[n].count < 4 )
1046        continue;
1047
1048      /* compute first segment in contour */
1049      first = glyph->contours[n].start;
1050
1051      start = end = first;
1052      do
1053      {
1054        end = end->next;
1055        if ( end == first )
1056          goto Skip;
1057
1058        in_x = end->org_u - start->org_u;
1059        in_y = end->org_v - start->org_v;
1060
1061      } while ( in_x == 0 && in_y == 0 );
1062
1063      /* extend the segment start whenever possible */
1064      before = start;
1065      do
1066      {
1067        do
1068        {
1069          start  = before;
1070          before = before->prev;
1071          if ( before == first )
1072            goto Skip;
1073
1074          out_x = start->org_u - before->org_u;
1075          out_y = start->org_v - before->org_v;
1076
1077        } while ( out_x == 0 && out_y == 0 );
1078
1079        orient_prev = psh_corner_orientation( in_x, in_y, out_x, out_y );
1080
1081      } while ( orient_prev == 0 );
1082
1083      first = start;
1084      in_x  = out_x;
1085      in_y  = out_y;
1086
1087      /* now, process all segments in the contour */
1088      do
1089      {
1090        /* first, extend current segment's end whenever possible */
1091        after = end;
1092        do
1093        {
1094          do
1095          {
1096            end   = after;
1097            after = after->next;
1098            if ( after == first )
1099              finished = 1;
1100
1101            out_x = after->org_u - end->org_u;
1102            out_y = after->org_v - end->org_v;
1103
1104          } while ( out_x == 0 && out_y == 0 );
1105
1106          orient_cur = psh_corner_orientation( in_x, in_y, out_x, out_y );
1107
1108        } while ( orient_cur == 0 );
1109
1110        if ( ( orient_cur ^ orient_prev ) < 0 )
1111        {
1112          do
1113          {
1114            psh_point_set_inflex( start );
1115            start = start->next;
1116          }
1117          while ( start != end );
1118
1119          psh_point_set_inflex( start );
1120        }
1121
1122        start       = end;
1123        end         = after;
1124        orient_prev = orient_cur;
1125        in_x        = out_x;
1126        in_y        = out_y;
1127
1128      } while ( !finished );
1129
1130    Skip:
1131      ;
1132    }
1133  }
1134
1135#endif /* COMPUTE_INFLEXS */
1136
1137
1138  static void
1139  psh_glyph_done( PSH_Glyph  glyph )
1140  {
1141    FT_Memory  memory = glyph->memory;
1142
1143
1144    psh_hint_table_done( &glyph->hint_tables[1], memory );
1145    psh_hint_table_done( &glyph->hint_tables[0], memory );
1146
1147    FT_FREE( glyph->points );
1148    FT_FREE( glyph->contours );
1149
1150    glyph->num_points   = 0;
1151    glyph->num_contours = 0;
1152
1153    glyph->memory = 0;
1154  }
1155
1156
1157  static int
1158  psh_compute_dir( FT_Pos  dx,
1159                   FT_Pos  dy )
1160  {
1161    FT_Pos  ax, ay;
1162    int     result = PSH_DIR_NONE;
1163
1164
1165    ax = ( dx >= 0 ) ? dx : -dx;
1166    ay = ( dy >= 0 ) ? dy : -dy;
1167
1168    if ( ay * 12 < ax )
1169    {
1170      /* |dy| <<< |dx|  means a near-horizontal segment */
1171      result = ( dx >= 0 ) ? PSH_DIR_RIGHT : PSH_DIR_LEFT;
1172    }
1173    else if ( ax * 12 < ay )
1174    {
1175      /* |dx| <<< |dy|  means a near-vertical segment */
1176      result = ( dy >= 0 ) ? PSH_DIR_UP : PSH_DIR_DOWN;
1177    }
1178
1179    return result;
1180  }
1181
1182
1183  /* load outline point coordinates into hinter glyph */
1184  static void
1185  psh_glyph_load_points( PSH_Glyph  glyph,
1186                         FT_Int     dimension )
1187  {
1188    FT_Vector*  vec   = glyph->outline->points;
1189    PSH_Point   point = glyph->points;
1190    FT_UInt     count = glyph->num_points;
1191
1192
1193    for ( ; count > 0; count--, point++, vec++ )
1194    {
1195      point->flags2 = 0;
1196      point->hint   = NULL;
1197      if ( dimension == 0 )
1198      {
1199        point->org_u = vec->x;
1200        point->org_v = vec->y;
1201      }
1202      else
1203      {
1204        point->org_u = vec->y;
1205        point->org_v = vec->x;
1206      }
1207
1208#ifdef DEBUG_HINTER
1209      point->org_x = vec->x;
1210      point->org_y = vec->y;
1211#endif
1212
1213    }
1214  }
1215
1216
1217  /* save hinted point coordinates back to outline */
1218  static void
1219  psh_glyph_save_points( PSH_Glyph  glyph,
1220                         FT_Int     dimension )
1221  {
1222    FT_UInt     n;
1223    PSH_Point   point = glyph->points;
1224    FT_Vector*  vec   = glyph->outline->points;
1225    char*       tags  = glyph->outline->tags;
1226
1227
1228    for ( n = 0; n < glyph->num_points; n++ )
1229    {
1230      if ( dimension == 0 )
1231        vec[n].x = point->cur_u;
1232      else
1233        vec[n].y = point->cur_u;
1234
1235      if ( psh_point_is_strong( point ) )
1236        tags[n] |= (char)( ( dimension == 0 ) ? 32 : 64 );
1237
1238#ifdef DEBUG_HINTER
1239
1240      if ( dimension == 0 )
1241      {
1242        point->cur_x   = point->cur_u;
1243        point->flags_x = point->flags2 | point->flags;
1244      }
1245      else
1246      {
1247        point->cur_y   = point->cur_u;
1248        point->flags_y = point->flags2 | point->flags;
1249      }
1250
1251#endif
1252
1253      point++;
1254    }
1255  }
1256
1257
1258  static FT_Error
1259  psh_glyph_init( PSH_Glyph    glyph,
1260                  FT_Outline*  outline,
1261                  PS_Hints     ps_hints,
1262                  PSH_Globals  globals )
1263  {
1264    FT_Error   error;
1265    FT_Memory  memory;
1266
1267
1268    /* clear all fields */
1269    FT_MEM_ZERO( glyph, sizeof ( *glyph ) );
1270
1271    memory = glyph->memory = globals->memory;
1272
1273    /* allocate and setup points + contours arrays */
1274    if ( FT_NEW_ARRAY( glyph->points,   outline->n_points   ) ||
1275         FT_NEW_ARRAY( glyph->contours, outline->n_contours ) )
1276      goto Exit;
1277
1278    glyph->num_points   = outline->n_points;
1279    glyph->num_contours = outline->n_contours;
1280
1281    {
1282      FT_UInt      first = 0, next, n;
1283      PSH_Point    points  = glyph->points;
1284      PSH_Contour  contour = glyph->contours;
1285
1286
1287      for ( n = 0; n < glyph->num_contours; n++ )
1288      {
1289        FT_Int     count;
1290        PSH_Point  point;
1291
1292
1293        next  = outline->contours[n] + 1;
1294        count = next - first;
1295
1296        contour->start = points + first;
1297        contour->count = (FT_UInt)count;
1298
1299        if ( count > 0 )
1300        {
1301          point = points + first;
1302
1303          point->prev    = points + next - 1;
1304          point->contour = contour;
1305
1306          for ( ; count > 1; count-- )
1307          {
1308            point[0].next = point + 1;
1309            point[1].prev = point;
1310            point++;
1311            point->contour = contour;
1312          }
1313          point->next = points + first;
1314        }
1315
1316        contour++;
1317        first = next;
1318      }
1319    }
1320
1321    {
1322      PSH_Point   points = glyph->points;
1323      PSH_Point   point  = points;
1324      FT_Vector*  vec    = outline->points;
1325      FT_UInt     n;
1326
1327
1328      for ( n = 0; n < glyph->num_points; n++, point++ )
1329      {
1330        FT_Int  n_prev = (FT_Int)( point->prev - points );
1331        FT_Int  n_next = (FT_Int)( point->next - points );
1332        FT_Pos  dxi, dyi, dxo, dyo;
1333
1334
1335        if ( !( outline->tags[n] & FT_CURVE_TAG_ON ) )
1336          point->flags = PSH_POINT_OFF;
1337
1338        dxi = vec[n].x - vec[n_prev].x;
1339        dyi = vec[n].y - vec[n_prev].y;
1340
1341        point->dir_in = (FT_Char)psh_compute_dir( dxi, dyi );
1342
1343        dxo = vec[n_next].x - vec[n].x;
1344        dyo = vec[n_next].y - vec[n].y;
1345
1346        point->dir_out = (FT_Char)psh_compute_dir( dxo, dyo );
1347
1348        /* detect smooth points */
1349        if ( point->flags & PSH_POINT_OFF )
1350          point->flags |= PSH_POINT_SMOOTH;
1351
1352        else if ( point->dir_in == point->dir_out )
1353        {
1354          if ( point->dir_out != PSH_DIR_NONE           ||
1355               psh_corner_is_flat( dxi, dyi, dxo, dyo ) )
1356            point->flags |= PSH_POINT_SMOOTH;
1357        }
1358      }
1359    }
1360
1361    glyph->outline = outline;
1362    glyph->globals = globals;
1363
1364#ifdef COMPUTE_INFLEXS
1365    psh_glyph_load_points( glyph, 0 );
1366    psh_glyph_compute_inflections( glyph );
1367#endif /* COMPUTE_INFLEXS */
1368
1369    /* now deal with hints tables */
1370    error = psh_hint_table_init( &glyph->hint_tables [0],
1371                                 &ps_hints->dimension[0].hints,
1372                                 &ps_hints->dimension[0].masks,
1373                                 &ps_hints->dimension[0].counters,
1374                                 memory );
1375    if ( error )
1376      goto Exit;
1377
1378    error = psh_hint_table_init( &glyph->hint_tables [1],
1379                                 &ps_hints->dimension[1].hints,
1380                                 &ps_hints->dimension[1].masks,
1381                                 &ps_hints->dimension[1].counters,
1382                                 memory );
1383    if ( error )
1384      goto Exit;
1385
1386  Exit:
1387    return error;
1388  }
1389
1390
1391  /* compute all extrema in a glyph for a given dimension */
1392  static void
1393  psh_glyph_compute_extrema( PSH_Glyph  glyph )
1394  {
1395    FT_UInt  n;
1396
1397
1398    /* first of all, compute all local extrema */
1399    for ( n = 0; n < glyph->num_contours; n++ )
1400    {
1401      PSH_Point  first = glyph->contours[n].start;
1402      PSH_Point  point, before, after;
1403
1404
1405      if ( glyph->contours[n].count == 0 )
1406        continue;
1407
1408      point  = first;
1409      before = point;
1410      after  = point;
1411
1412      do
1413      {
1414        before = before->prev;
1415        if ( before == first )
1416          goto Skip;
1417
1418      } while ( before->org_u == point->org_u );
1419
1420      first = point = before->next;
1421
1422      for (;;)
1423      {
1424        after = point;
1425        do
1426        {
1427          after = after->next;
1428          if ( after == first )
1429            goto Next;
1430
1431        } while ( after->org_u == point->org_u );
1432
1433        if ( before->org_u < point->org_u )
1434        {
1435          if ( after->org_u < point->org_u )
1436          {
1437            /* local maximum */
1438            goto Extremum;
1439          }
1440        }
1441        else /* before->org_u > point->org_u */
1442        {
1443          if ( after->org_u > point->org_u )
1444          {
1445            /* local minimum */
1446          Extremum:
1447            do
1448            {
1449              psh_point_set_extremum( point );
1450              point = point->next;
1451
1452            } while ( point != after );
1453          }
1454        }
1455
1456        before = after->prev;
1457        point  = after;
1458
1459      } /* for  */
1460
1461    Next:
1462      ;
1463    }
1464
1465    /* for each extremum, determine its direction along the */
1466    /* orthogonal axis                                      */
1467    for ( n = 0; n < glyph->num_points; n++ )
1468    {
1469      PSH_Point  point, before, after;
1470
1471
1472      point  = &glyph->points[n];
1473      before = point;
1474      after  = point;
1475
1476      if ( psh_point_is_extremum( point ) )
1477      {
1478        do
1479        {
1480          before = before->prev;
1481          if ( before == point )
1482            goto Skip;
1483
1484        } while ( before->org_v == point->org_v );
1485
1486        do
1487        {
1488          after = after->next;
1489          if ( after == point )
1490            goto Skip;
1491
1492        } while ( after->org_v == point->org_v );
1493      }
1494
1495      if ( before->org_v < point->org_v &&
1496           after->org_v  > point->org_v )
1497      {
1498        psh_point_set_positive( point );
1499      }
1500      else if ( before->org_v > point->org_v &&
1501                after->org_v  < point->org_v )
1502      {
1503        psh_point_set_negative( point );
1504      }
1505
1506    Skip:
1507      ;
1508    }
1509  }
1510
1511
1512  /* major_dir is the direction for points on the bottom/left of the stem; */
1513  /* Points on the top/right of the stem will have a direction of          */
1514  /* -major_dir.                                                           */
1515
1516  static void
1517  psh_hint_table_find_strong_points( PSH_Hint_Table  table,
1518                                     PSH_Point       point,
1519                                     FT_UInt         count,
1520                                     FT_Int          threshold,
1521                                     FT_Int          major_dir )
1522  {
1523    PSH_Hint*  sort      = table->sort;
1524    FT_UInt    num_hints = table->num_hints;
1525
1526
1527    for ( ; count > 0; count--, point++ )
1528    {
1529      FT_Int  point_dir = 0;
1530      FT_Pos  org_u     = point->org_u;
1531
1532
1533      if ( psh_point_is_strong( point ) )
1534        continue;
1535
1536      if ( PSH_DIR_COMPARE( point->dir_in, major_dir ) )
1537        point_dir = point->dir_in;
1538
1539      else if ( PSH_DIR_COMPARE( point->dir_out, major_dir ) )
1540        point_dir = point->dir_out;
1541
1542      if ( point_dir )
1543      {
1544        if ( point_dir == major_dir )
1545        {
1546          FT_UInt  nn;
1547
1548
1549          for ( nn = 0; nn < num_hints; nn++ )
1550          {
1551            PSH_Hint  hint = sort[nn];
1552            FT_Pos    d    = org_u - hint->org_pos;
1553
1554
1555            if ( d < threshold && -d < threshold )
1556            {
1557              psh_point_set_strong( point );
1558              point->flags2 |= PSH_POINT_EDGE_MIN;
1559              point->hint    = hint;
1560              break;
1561            }
1562          }
1563        }
1564        else if ( point_dir == -major_dir )
1565        {
1566          FT_UInt  nn;
1567
1568
1569          for ( nn = 0; nn < num_hints; nn++ )
1570          {
1571            PSH_Hint  hint = sort[nn];
1572            FT_Pos    d    = org_u - hint->org_pos - hint->org_len;
1573
1574
1575            if ( d < threshold && -d < threshold )
1576            {
1577              psh_point_set_strong( point );
1578              point->flags2 |= PSH_POINT_EDGE_MAX;
1579              point->hint    = hint;
1580              break;
1581            }
1582          }
1583        }
1584      }
1585
1586#if 1
1587      else if ( psh_point_is_extremum( point ) )
1588      {
1589        /* treat extrema as special cases for stem edge alignment */
1590        FT_UInt  nn, min_flag, max_flag;
1591
1592
1593        if ( major_dir == PSH_DIR_HORIZONTAL )
1594        {
1595          min_flag = PSH_POINT_POSITIVE;
1596          max_flag = PSH_POINT_NEGATIVE;
1597        }
1598        else
1599        {
1600          min_flag = PSH_POINT_NEGATIVE;
1601          max_flag = PSH_POINT_POSITIVE;
1602        }
1603
1604        if ( point->flags2 & min_flag )
1605        {
1606          for ( nn = 0; nn < num_hints; nn++ )
1607          {
1608            PSH_Hint  hint = sort[nn];
1609            FT_Pos    d    = org_u - hint->org_pos;
1610
1611
1612            if ( d < threshold && -d < threshold )
1613            {
1614              point->flags2 |= PSH_POINT_EDGE_MIN;
1615              point->hint    = hint;
1616              psh_point_set_strong( point );
1617              break;
1618            }
1619          }
1620        }
1621        else if ( point->flags2 & max_flag )
1622        {
1623          for ( nn = 0; nn < num_hints; nn++ )
1624          {
1625            PSH_Hint  hint = sort[nn];
1626            FT_Pos    d    = org_u - hint->org_pos - hint->org_len;
1627
1628
1629            if ( d < threshold && -d < threshold )
1630            {
1631              point->flags2 |= PSH_POINT_EDGE_MAX;
1632              point->hint    = hint;
1633              psh_point_set_strong( point );
1634              break;
1635            }
1636          }
1637        }
1638
1639        if ( point->hint == NULL )
1640        {
1641          for ( nn = 0; nn < num_hints; nn++ )
1642          {
1643            PSH_Hint  hint = sort[nn];
1644
1645
1646            if ( org_u >= hint->org_pos                 &&
1647                org_u <= hint->org_pos + hint->org_len )
1648            {
1649              point->hint = hint;
1650              break;
1651            }
1652          }
1653        }
1654      }
1655
1656#endif /* 1 */
1657    }
1658  }
1659
1660
1661  /* the accepted shift for strong points in fractional pixels */
1662#define PSH_STRONG_THRESHOLD  32
1663
1664  /* the maximum shift value in font units */
1665#define PSH_STRONG_THRESHOLD_MAXIMUM  30
1666
1667
1668  /* find strong points in a glyph */
1669  static void
1670  psh_glyph_find_strong_points( PSH_Glyph  glyph,
1671                                FT_Int     dimension )
1672  {
1673    /* a point is `strong' if it is located on a stem edge and       */
1674    /* has an `in' or `out' tangent parallel to the hint's direction */
1675
1676    PSH_Hint_Table  table     = &glyph->hint_tables[dimension];
1677    PS_Mask         mask      = table->hint_masks->masks;
1678    FT_UInt         num_masks = table->hint_masks->num_masks;
1679    FT_UInt         first     = 0;
1680    FT_Int          major_dir = dimension == 0 ? PSH_DIR_VERTICAL
1681                                               : PSH_DIR_HORIZONTAL;
1682    PSH_Dimension   dim       = &glyph->globals->dimension[dimension];
1683    FT_Fixed        scale     = dim->scale_mult;
1684    FT_Int          threshold;
1685
1686
1687    threshold = (FT_Int)FT_DivFix( PSH_STRONG_THRESHOLD, scale );
1688    if ( threshold > PSH_STRONG_THRESHOLD_MAXIMUM )
1689      threshold = PSH_STRONG_THRESHOLD_MAXIMUM;
1690
1691    /* process secondary hints to `selected' points */
1692    if ( num_masks > 1 && glyph->num_points > 0 )
1693    {
1694      /* the `endchar' op can reduce the number of points */
1695      first = mask->end_point > glyph->num_points
1696                ? glyph->num_points
1697                : mask->end_point;
1698      mask++;
1699      for ( ; num_masks > 1; num_masks--, mask++ )
1700      {
1701        FT_UInt  next;
1702        FT_Int   count;
1703
1704
1705        next  = mask->end_point > glyph->num_points
1706                  ? glyph->num_points
1707                  : mask->end_point;
1708        count = next - first;
1709        if ( count > 0 )
1710        {
1711          PSH_Point  point = glyph->points + first;
1712
1713
1714          psh_hint_table_activate_mask( table, mask );
1715
1716          psh_hint_table_find_strong_points( table, point, count,
1717                                             threshold, major_dir );
1718        }
1719        first = next;
1720      }
1721    }
1722
1723    /* process primary hints for all points */
1724    if ( num_masks == 1 )
1725    {
1726      FT_UInt    count = glyph->num_points;
1727      PSH_Point  point = glyph->points;
1728
1729
1730      psh_hint_table_activate_mask( table, table->hint_masks->masks );
1731
1732      psh_hint_table_find_strong_points( table, point, count,
1733                                         threshold, major_dir );
1734    }
1735
1736    /* now, certain points may have been attached to a hint and */
1737    /* not marked as strong; update their flags then            */
1738    {
1739      FT_UInt    count = glyph->num_points;
1740      PSH_Point  point = glyph->points;
1741
1742
1743      for ( ; count > 0; count--, point++ )
1744        if ( point->hint && !psh_point_is_strong( point ) )
1745          psh_point_set_strong( point );
1746    }
1747  }
1748
1749
1750  /* find points in a glyph which are in a blue zone and have `in' or */
1751  /* `out' tangents parallel to the horizontal axis                   */
1752  static void
1753  psh_glyph_find_blue_points( PSH_Blues  blues,
1754                              PSH_Glyph  glyph )
1755  {
1756    PSH_Blue_Table  table;
1757    PSH_Blue_Zone   zone;
1758    FT_UInt         glyph_count = glyph->num_points;
1759    FT_UInt         blue_count;
1760    PSH_Point       point = glyph->points;
1761
1762
1763    for ( ; glyph_count > 0; glyph_count--, point++ )
1764    {
1765      FT_Pos  y;
1766
1767
1768      /* check tangents */
1769      if ( !PSH_DIR_COMPARE( point->dir_in,  PSH_DIR_HORIZONTAL ) &&
1770           !PSH_DIR_COMPARE( point->dir_out, PSH_DIR_HORIZONTAL ) )
1771        continue;
1772
1773      /* skip strong points */
1774      if ( psh_point_is_strong( point ) )
1775        continue;
1776
1777      y = point->org_u;
1778
1779      /* look up top zones */
1780      table      = &blues->normal_top;
1781      blue_count = table->count;
1782      zone       = table->zones;
1783
1784      for ( ; blue_count > 0; blue_count--, zone++ )
1785      {
1786        FT_Pos  delta = y - zone->org_bottom;
1787
1788
1789        if ( delta < -blues->blue_fuzz )
1790          break;
1791
1792        if ( y <= zone->org_top + blues->blue_fuzz )
1793          if ( blues->no_overshoots || delta <= blues->blue_threshold )
1794          {
1795            point->cur_u = zone->cur_bottom;
1796            psh_point_set_strong( point );
1797            psh_point_set_fitted( point );
1798          }
1799      }
1800
1801      /* look up bottom zones */
1802      table      = &blues->normal_bottom;
1803      blue_count = table->count;
1804      zone       = table->zones + blue_count - 1;
1805
1806      for ( ; blue_count > 0; blue_count--, zone-- )
1807      {
1808        FT_Pos  delta = zone->org_top - y;
1809
1810
1811        if ( delta < -blues->blue_fuzz )
1812          break;
1813
1814        if ( y >= zone->org_bottom - blues->blue_fuzz )
1815          if ( blues->no_overshoots || delta < blues->blue_threshold )
1816          {
1817            point->cur_u = zone->cur_top;
1818            psh_point_set_strong( point );
1819            psh_point_set_fitted( point );
1820          }
1821      }
1822    }
1823  }
1824
1825
1826  /* interpolate strong points with the help of hinted coordinates */
1827  static void
1828  psh_glyph_interpolate_strong_points( PSH_Glyph  glyph,
1829                                       FT_Int     dimension )
1830  {
1831    PSH_Dimension  dim   = &glyph->globals->dimension[dimension];
1832    FT_Fixed       scale = dim->scale_mult;
1833
1834    FT_UInt        count = glyph->num_points;
1835    PSH_Point      point = glyph->points;
1836
1837
1838    for ( ; count > 0; count--, point++ )
1839    {
1840      PSH_Hint  hint = point->hint;
1841
1842
1843      if ( hint )
1844      {
1845        FT_Pos  delta;
1846
1847
1848        if ( psh_point_is_edge_min( point ) )
1849          point->cur_u = hint->cur_pos;
1850
1851        else if ( psh_point_is_edge_max( point ) )
1852          point->cur_u = hint->cur_pos + hint->cur_len;
1853
1854        else
1855        {
1856          delta = point->org_u - hint->org_pos;
1857
1858          if ( delta <= 0 )
1859            point->cur_u = hint->cur_pos + FT_MulFix( delta, scale );
1860
1861          else if ( delta >= hint->org_len )
1862            point->cur_u = hint->cur_pos + hint->cur_len +
1863                             FT_MulFix( delta - hint->org_len, scale );
1864
1865          else /* hint->org_len > 0 */
1866            point->cur_u = hint->cur_pos +
1867                             FT_MulDiv( delta, hint->cur_len,
1868                                        hint->org_len );
1869        }
1870        psh_point_set_fitted( point );
1871      }
1872    }
1873  }
1874
1875
1876#define  PSH_MAX_STRONG_INTERNAL  16
1877
1878  static void
1879  psh_glyph_interpolate_normal_points( PSH_Glyph  glyph,
1880                                       FT_Int     dimension )
1881  {
1882
1883#if 1
1884    /* first technique: a point is strong if it is a local extremum */
1885
1886    PSH_Dimension  dim    = &glyph->globals->dimension[dimension];
1887    FT_Fixed       scale  = dim->scale_mult;
1888    FT_Memory      memory = glyph->memory;
1889
1890    PSH_Point*     strongs     = NULL;
1891    PSH_Point      strongs_0[PSH_MAX_STRONG_INTERNAL];
1892    FT_UInt        num_strongs = 0;
1893
1894    PSH_Point      points = glyph->points;
1895    PSH_Point      points_end = points + glyph->num_points;
1896    PSH_Point      point;
1897
1898
1899    /* first count the number of strong points */
1900    for ( point = points; point < points_end; point++ )
1901    {
1902      if ( psh_point_is_strong( point ) )
1903        num_strongs++;
1904    }
1905
1906    if ( num_strongs == 0 )  /* nothing to do here */
1907      return;
1908
1909    /* allocate an array to store a list of points, */
1910    /* stored in increasing org_u order             */
1911    if ( num_strongs <= PSH_MAX_STRONG_INTERNAL )
1912      strongs = strongs_0;
1913    else
1914    {
1915      FT_Error  error;
1916
1917
1918      if ( FT_NEW_ARRAY( strongs, num_strongs ) )
1919        return;
1920    }
1921
1922    num_strongs = 0;
1923    for ( point = points; point < points_end; point++ )
1924    {
1925      PSH_Point*  insert;
1926
1927
1928      if ( !psh_point_is_strong( point ) )
1929        continue;
1930
1931      for ( insert = strongs + num_strongs; insert > strongs; insert-- )
1932      {
1933        if ( insert[-1]->org_u <= point->org_u )
1934          break;
1935
1936        insert[0] = insert[-1];
1937      }
1938      insert[0] = point;
1939      num_strongs++;
1940    }
1941
1942    /* now try to interpolate all normal points */
1943    for ( point = points; point < points_end; point++ )
1944    {
1945      if ( psh_point_is_strong( point ) )
1946        continue;
1947
1948      /* sometimes, some local extrema are smooth points */
1949      if ( psh_point_is_smooth( point ) )
1950      {
1951        if ( point->dir_in == PSH_DIR_NONE   ||
1952             point->dir_in != point->dir_out )
1953          continue;
1954
1955        if ( !psh_point_is_extremum( point ) &&
1956             !psh_point_is_inflex( point )   )
1957          continue;
1958
1959        point->flags &= ~PSH_POINT_SMOOTH;
1960      }
1961
1962      /* find best enclosing point coordinates then interpolate */
1963      {
1964        PSH_Point   before, after;
1965        FT_UInt     nn;
1966
1967
1968        for ( nn = 0; nn < num_strongs; nn++ )
1969          if ( strongs[nn]->org_u > point->org_u )
1970            break;
1971
1972        if ( nn == 0 )  /* point before the first strong point */
1973        {
1974          after = strongs[0];
1975
1976          point->cur_u = after->cur_u +
1977                           FT_MulFix( point->org_u - after->org_u,
1978                                      scale );
1979        }
1980        else
1981        {
1982          before = strongs[nn - 1];
1983
1984          for ( nn = num_strongs; nn > 0; nn-- )
1985            if ( strongs[nn - 1]->org_u < point->org_u )
1986              break;
1987
1988          if ( nn == num_strongs )  /* point is after last strong point */
1989          {
1990            before = strongs[nn - 1];
1991
1992            point->cur_u = before->cur_u +
1993                             FT_MulFix( point->org_u - before->org_u,
1994                                        scale );
1995          }
1996          else
1997          {
1998            FT_Pos  u;
1999
2000
2001            after = strongs[nn];
2002
2003            /* now interpolate point between before and after */
2004            u = point->org_u;
2005
2006            if ( u == before->org_u )
2007              point->cur_u = before->cur_u;
2008
2009            else if ( u == after->org_u )
2010              point->cur_u = after->cur_u;
2011
2012            else
2013              point->cur_u = before->cur_u +
2014                               FT_MulDiv( u - before->org_u,
2015                                          after->cur_u - before->cur_u,
2016                                          after->org_u - before->org_u );
2017          }
2018        }
2019        psh_point_set_fitted( point );
2020      }
2021    }
2022
2023    if ( strongs != strongs_0 )
2024      FT_FREE( strongs );
2025
2026#endif /* 1 */
2027
2028  }
2029
2030
2031  /* interpolate other points */
2032  static void
2033  psh_glyph_interpolate_other_points( PSH_Glyph  glyph,
2034                                      FT_Int     dimension )
2035  {
2036    PSH_Dimension  dim          = &glyph->globals->dimension[dimension];
2037    FT_Fixed       scale        = dim->scale_mult;
2038    FT_Fixed       delta        = dim->scale_delta;
2039    PSH_Contour    contour      = glyph->contours;
2040    FT_UInt        num_contours = glyph->num_contours;
2041
2042
2043    for ( ; num_contours > 0; num_contours--, contour++ )
2044    {
2045      PSH_Point  start = contour->start;
2046      PSH_Point  first, next, point;
2047      FT_UInt    fit_count;
2048
2049
2050      /* count the number of strong points in this contour */
2051      next      = start + contour->count;
2052      fit_count = 0;
2053      first     = 0;
2054
2055      for ( point = start; point < next; point++ )
2056        if ( psh_point_is_fitted( point ) )
2057        {
2058          if ( !first )
2059            first = point;
2060
2061          fit_count++;
2062        }
2063
2064      /* if there are less than 2 fitted points in the contour, we */
2065      /* simply scale and eventually translate the contour points  */
2066      if ( fit_count < 2 )
2067      {
2068        if ( fit_count == 1 )
2069          delta = first->cur_u - FT_MulFix( first->org_u, scale );
2070
2071        for ( point = start; point < next; point++ )
2072          if ( point != first )
2073            point->cur_u = FT_MulFix( point->org_u, scale ) + delta;
2074
2075        goto Next_Contour;
2076      }
2077
2078      /* there are more than 2 strong points in this contour; we */
2079      /* need to interpolate weak points between them            */
2080      start = first;
2081      do
2082      {
2083        point = first;
2084
2085        /* skip consecutive fitted points */
2086        for (;;)
2087        {
2088          next = first->next;
2089          if ( next == start )
2090            goto Next_Contour;
2091
2092          if ( !psh_point_is_fitted( next ) )
2093            break;
2094
2095          first = next;
2096        }
2097
2098        /* find next fitted point after unfitted one */
2099        for (;;)
2100        {
2101          next = next->next;
2102          if ( psh_point_is_fitted( next ) )
2103            break;
2104        }
2105
2106        /* now interpolate between them */
2107        {
2108          FT_Pos    org_a, org_ab, cur_a, cur_ab;
2109          FT_Pos    org_c, org_ac, cur_c;
2110          FT_Fixed  scale_ab;
2111
2112
2113          if ( first->org_u <= next->org_u )
2114          {
2115            org_a  = first->org_u;
2116            cur_a  = first->cur_u;
2117            org_ab = next->org_u - org_a;
2118            cur_ab = next->cur_u - cur_a;
2119          }
2120          else
2121          {
2122            org_a  = next->org_u;
2123            cur_a  = next->cur_u;
2124            org_ab = first->org_u - org_a;
2125            cur_ab = first->cur_u - cur_a;
2126          }
2127
2128          scale_ab = 0x10000L;
2129          if ( org_ab > 0 )
2130            scale_ab = FT_DivFix( cur_ab, org_ab );
2131
2132          point = first->next;
2133          do
2134          {
2135            org_c  = point->org_u;
2136            org_ac = org_c - org_a;
2137
2138            if ( org_ac <= 0 )
2139            {
2140              /* on the left of the interpolation zone */
2141              cur_c = cur_a + FT_MulFix( org_ac, scale );
2142            }
2143            else if ( org_ac >= org_ab )
2144            {
2145              /* on the right on the interpolation zone */
2146              cur_c = cur_a + cur_ab + FT_MulFix( org_ac - org_ab, scale );
2147            }
2148            else
2149            {
2150              /* within the interpolation zone */
2151              cur_c = cur_a + FT_MulFix( org_ac, scale_ab );
2152            }
2153
2154            point->cur_u = cur_c;
2155
2156            point = point->next;
2157
2158          } while ( point != next );
2159        }
2160
2161        /* keep going until all points in the contours have been processed */
2162        first = next;
2163
2164      } while ( first != start );
2165
2166    Next_Contour:
2167      ;
2168    }
2169  }
2170
2171
2172  /*************************************************************************/
2173  /*************************************************************************/
2174  /*****                                                               *****/
2175  /*****                     HIGH-LEVEL INTERFACE                      *****/
2176  /*****                                                               *****/
2177  /*************************************************************************/
2178  /*************************************************************************/
2179
2180  FT_Error
2181  ps_hints_apply( PS_Hints        ps_hints,
2182                  FT_Outline*     outline,
2183                  PSH_Globals     globals,
2184                  FT_Render_Mode  hint_mode )
2185  {
2186    PSH_GlyphRec  glyphrec;
2187    PSH_Glyph     glyph = &glyphrec;
2188    FT_Error      error;
2189#ifdef DEBUG_HINTER
2190    FT_Memory     memory;
2191#endif
2192    FT_Int        dimension;
2193
2194
2195    /* something to do? */
2196    if ( outline->n_points == 0 || outline->n_contours == 0 )
2197      return PSH_Err_Ok;
2198
2199#ifdef DEBUG_HINTER
2200
2201    memory = globals->memory;
2202
2203    if ( ps_debug_glyph )
2204    {
2205      psh_glyph_done( ps_debug_glyph );
2206      FT_FREE( ps_debug_glyph );
2207    }
2208
2209    if ( FT_NEW( glyph ) )
2210      return error;
2211
2212    ps_debug_glyph = glyph;
2213
2214#endif /* DEBUG_HINTER */
2215
2216    error = psh_glyph_init( glyph, outline, ps_hints, globals );
2217    if ( error )
2218      goto Exit;
2219
2220    /* try to optimize the y_scale so that the top of non-capital letters
2221     * is aligned on a pixel boundary whenever possible
2222     */
2223    {
2224      PSH_Dimension  dim_x = &glyph->globals->dimension[0];
2225      PSH_Dimension  dim_y = &glyph->globals->dimension[1];
2226
2227      FT_Fixed  x_scale = dim_x->scale_mult;
2228      FT_Fixed  y_scale = dim_y->scale_mult;
2229
2230      FT_Fixed  old_x_scale = x_scale;
2231      FT_Fixed  old_y_scale = y_scale;
2232
2233      FT_Fixed  scaled;
2234      FT_Fixed  fitted;
2235
2236      FT_Bool  rescale = FALSE;
2237
2238
2239      scaled = FT_MulFix( globals->blues.normal_top.zones->org_ref, y_scale );
2240      fitted = FT_PIX_ROUND( scaled );
2241
2242      if ( fitted != 0 && scaled != fitted )
2243      {
2244        rescale = TRUE;
2245
2246        y_scale = FT_MulDiv( y_scale, fitted, scaled );
2247
2248        if ( fitted < scaled )
2249          x_scale -= x_scale / 50;
2250
2251        psh_globals_set_scale( glyph->globals, x_scale, y_scale, 0, 0 );
2252      }
2253
2254      glyph->do_horz_hints = 1;
2255      glyph->do_vert_hints = 1;
2256
2257      glyph->do_horz_snapping = FT_BOOL( hint_mode == FT_RENDER_MODE_MONO ||
2258                                         hint_mode == FT_RENDER_MODE_LCD  );
2259
2260      glyph->do_vert_snapping = FT_BOOL( hint_mode == FT_RENDER_MODE_MONO  ||
2261                                         hint_mode == FT_RENDER_MODE_LCD_V );
2262
2263      glyph->do_stem_adjust   = FT_BOOL( hint_mode != FT_RENDER_MODE_LIGHT );
2264
2265      for ( dimension = 0; dimension < 2; dimension++ )
2266      {
2267        /* load outline coordinates into glyph */
2268        psh_glyph_load_points( glyph, dimension );
2269
2270        /* compute local extrema */
2271        psh_glyph_compute_extrema( glyph );
2272
2273        /* compute aligned stem/hints positions */
2274        psh_hint_table_align_hints( &glyph->hint_tables[dimension],
2275                                    glyph->globals,
2276                                    dimension,
2277                                    glyph );
2278
2279        /* find strong points, align them, then interpolate others */
2280        psh_glyph_find_strong_points( glyph, dimension );
2281        if ( dimension == 1 )
2282          psh_glyph_find_blue_points( &globals->blues, glyph );
2283        psh_glyph_interpolate_strong_points( glyph, dimension );
2284        psh_glyph_interpolate_normal_points( glyph, dimension );
2285        psh_glyph_interpolate_other_points( glyph, dimension );
2286
2287        /* save hinted coordinates back to outline */
2288        psh_glyph_save_points( glyph, dimension );
2289
2290        if ( rescale )
2291          psh_globals_set_scale( glyph->globals,
2292                                 old_x_scale, old_y_scale, 0, 0 );
2293      }
2294    }
2295
2296  Exit:
2297
2298#ifndef DEBUG_HINTER
2299    psh_glyph_done( glyph );
2300#endif
2301
2302    return error;
2303  }
2304
2305
2306/* END */
2307