aboutsummaryrefslogtreecommitdiff
path: root/freetype/src/pshinter/pshglob.c
blob: 9285efc9e166369243ed31351e788620a2fe4e07 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
/***************************************************************************/
/*                                                                         */
/*  pshglob.c                                                              */
/*                                                                         */
/*    PostScript hinter global hinting management (body).                  */
/*    Inspired by the new auto-hinter module.                              */
/*                                                                         */
/*  Copyright 2001-2004, 2006, 2010, 2012 by                               */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used        */
/*  modified and distributed under the terms of the FreeType project       */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_FREETYPE_H
#include FT_INTERNAL_OBJECTS_H
#include "pshglob.h"

#ifdef DEBUG_HINTER
  PSH_Globals  ps_debug_globals = 0;
#endif


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       STANDARD WIDTHS                         *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/


  /* scale the widths/heights table */
  static void
  psh_globals_scale_widths( PSH_Globals  globals,
                            FT_UInt      direction )
  {
    PSH_Dimension  dim   = &globals->dimension[direction];
    PSH_Widths     stdw  = &dim->stdw;
    FT_UInt        count = stdw->count;
    PSH_Width      width = stdw->widths;
    PSH_Width      stand = width;               /* standard width/height */
    FT_Fixed       scale = dim->scale_mult;


    if ( count > 0 )
    {
      width->cur = FT_MulFix( width->org, scale );
      width->fit = FT_PIX_ROUND( width->cur );

      width++;
      count--;

      for ( ; count > 0; count--, width++ )
      {
        FT_Pos  w, dist;


        w    = FT_MulFix( width->org, scale );
        dist = w - stand->cur;

        if ( dist < 0 )
          dist = -dist;

        if ( dist < 128 )
          w = stand->cur;

        width->cur = w;
        width->fit = FT_PIX_ROUND( w );
      }
    }
  }


#if 0

  /* org_width is is font units, result in device pixels, 26.6 format */
  FT_LOCAL_DEF( FT_Pos )
  psh_dimension_snap_width( PSH_Dimension  dimension,
                            FT_Int         org_width )
  {
    FT_UInt  n;
    FT_Pos   width     = FT_MulFix( org_width, dimension->scale_mult );
    FT_Pos   best      = 64 + 32 + 2;
    FT_Pos   reference = width;


    for ( n = 0; n < dimension->stdw.count; n++ )
    {
      FT_Pos  w;
      FT_Pos  dist;


      w = dimension->stdw.widths[n].cur;
      dist = width - w;
      if ( dist < 0 )
        dist = -dist;
      if ( dist < best )
      {
        best      = dist;
        reference = w;
      }
    }

    if ( width >= reference )
    {
      width -= 0x21;
      if ( width < reference )
        width = reference;
    }
    else
    {
      width += 0x21;
      if ( width > reference )
        width = reference;
    }

    return width;
  }

#endif /* 0 */


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                       BLUE ZONES                              *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static void
  psh_blues_set_zones_0( PSH_Blues       target,
                         FT_Bool         is_others,
                         FT_UInt         read_count,
                         FT_Short*       read,
                         PSH_Blue_Table  top_table,
                         PSH_Blue_Table  bot_table )
  {
    FT_UInt  count_top = top_table->count;
    FT_UInt  count_bot = bot_table->count;
    FT_Bool  first     = 1;

    FT_UNUSED( target );


    for ( ; read_count > 1; read_count -= 2 )
    {
      FT_Int         reference, delta;
      FT_UInt        count;
      PSH_Blue_Zone  zones, zone;
      FT_Bool        top;


      /* read blue zone entry, and select target top/bottom zone */
      top = 0;
      if ( first || is_others )
      {
        reference = read[1];
        delta     = read[0] - reference;

        zones = bot_table->zones;
        count = count_bot;
        first = 0;
      }
      else
      {
        reference = read[0];
        delta     = read[1] - reference;

        zones = top_table->zones;
        count = count_top;
        top   = 1;
      }

      /* insert into sorted table */
      zone = zones;
      for ( ; count > 0; count--, zone++ )
      {
        if ( reference < zone->org_ref )
          break;

        if ( reference == zone->org_ref )
        {
          FT_Int  delta0 = zone->org_delta;


          /* we have two zones on the same reference position -- */
          /* only keep the largest one                           */
          if ( delta < 0 )
          {
            if ( delta < delta0 )
              zone->org_delta = delta;
          }
          else
          {
            if ( delta > delta0 )
              zone->org_delta = delta;
          }
          goto Skip;
        }
      }

      for ( ; count > 0; count-- )
        zone[count] = zone[count-1];

      zone->org_ref   = reference;
      zone->org_delta = delta;

      if ( top )
        count_top++;
      else
        count_bot++;

    Skip:
      read += 2;
    }

    top_table->count = count_top;
    bot_table->count = count_bot;
  }


  /* Re-read blue zones from the original fonts and store them into out */
  /* private structure.  This function re-orders, sanitizes and         */
  /* fuzz-expands the zones as well.                                    */
  static void
  psh_blues_set_zones( PSH_Blues  target,
                       FT_UInt    count,
                       FT_Short*  blues,
                       FT_UInt    count_others,
                       FT_Short*  other_blues,
                       FT_Int     fuzz,
                       FT_Int     family )
  {
    PSH_Blue_Table  top_table, bot_table;
    FT_Int          count_top, count_bot;


    if ( family )
    {
      top_table = &target->family_top;
      bot_table = &target->family_bottom;
    }
    else
    {
      top_table = &target->normal_top;
      bot_table = &target->normal_bottom;
    }

    /* read the input blue zones, and build two sorted tables  */
    /* (one for the top zones, the other for the bottom zones) */
    top_table->count = 0;
    bot_table->count = 0;

    /* first, the blues */
    psh_blues_set_zones_0( target, 0,
                           count, blues, top_table, bot_table );
    psh_blues_set_zones_0( target, 1,
                           count_others, other_blues, top_table, bot_table );

    count_top = top_table->count;
    count_bot = bot_table->count;

    /* sanitize top table */
    if ( count_top > 0 )
    {
      PSH_Blue_Zone  zone = top_table->zones;


      for ( count = count_top; count > 0; count--, zone++ )
      {
        FT_Int  delta;


        if ( count > 1 )
        {
          delta = zone[1].org_ref - zone[0].org_ref;
          if ( zone->org_delta > delta )
            zone->org_delta = delta;
        }

        zone->org_bottom = zone->org_ref;
        zone->org_top    = zone->org_delta + zone->org_ref;
      }
    }

    /* sanitize bottom table */
    if ( count_bot > 0 )
    {
      PSH_Blue_Zone  zone = bot_table->zones;


      for ( count = count_bot; count > 0; count--, zone++ )
      {
        FT_Int  delta;


        if ( count > 1 )
        {
          delta = zone[0].org_ref - zone[1].org_ref;
          if ( zone->org_delta < delta )
            zone->org_delta = delta;
        }

        zone->org_top    = zone->org_ref;
        zone->org_bottom = zone->org_delta + zone->org_ref;
      }
    }

    /* expand top and bottom tables with blue fuzz */
    {
      FT_Int         dim, top, bot, delta;
      PSH_Blue_Zone  zone;


      zone  = top_table->zones;
      count = count_top;

      for ( dim = 1; dim >= 0; dim-- )
      {
        if ( count > 0 )
        {
          /* expand the bottom of the lowest zone normally */
          zone->org_bottom -= fuzz;

          /* expand the top and bottom of intermediate zones;    */
          /* checking that the interval is smaller than the fuzz */
          top = zone->org_top;

          for ( count--; count > 0; count-- )
          {
            bot   = zone[1].org_bottom;
            delta = bot - top;

            if ( delta < 2 * fuzz )
              zone[0].org_top = zone[1].org_bottom = top + delta / 2;
            else
            {
              zone[0].org_top    = top + fuzz;
              zone[1].org_bottom = bot - fuzz;
            }

            zone++;
            top = zone->org_top;
          }

          /* expand the top of the highest zone normally */
          zone->org_top = top + fuzz;
        }
        zone  = bot_table->zones;
        count = count_bot;
      }
    }
  }


  /* reset the blues table when the device transform changes */
  static void
  psh_blues_scale_zones( PSH_Blues  blues,
                         FT_Fixed   scale,
                         FT_Pos     delta )
  {
    FT_UInt         count;
    FT_UInt         num;
    PSH_Blue_Table  table = 0;

    /*                                                        */
    /* Determine whether we need to suppress overshoots or    */
    /* not.  We simply need to compare the vertical scale     */
    /* parameter to the raw bluescale value.  Here is why:    */
    /*                                                        */
    /*   We need to suppress overshoots for all pointsizes.   */
    /*   At 300dpi that satisfies:                            */
    /*                                                        */
    /*      pointsize < 240*bluescale + 0.49                  */
    /*                                                        */
    /*   This corresponds to:                                 */
    /*                                                        */
    /*      pixelsize < 1000*bluescale + 49/24                */
    /*                                                        */
    /*      scale*EM_Size < 1000*bluescale + 49/24            */
    /*                                                        */
    /*   However, for normal Type 1 fonts, EM_Size is 1000!   */
    /*   We thus only check:                                  */
    /*                                                        */
    /*      scale < bluescale + 49/24000                      */
    /*                                                        */
    /*   which we shorten to                                  */
    /*                                                        */
    /*      "scale < bluescale"                               */
    /*                                                        */
    /* Note that `blue_scale' is stored 1000 times its real   */
    /* value, and that `scale' converts from font units to    */
    /* fractional pixels.                                     */
    /*                                                        */

    /* 1000 / 64 = 125 / 8 */
    if ( scale >= 0x20C49BAL )
      blues->no_overshoots = FT_BOOL( scale < blues->blue_scale * 8 / 125 );
    else
      blues->no_overshoots = FT_BOOL( scale * 125 < blues->blue_scale * 8 );

    /*                                                        */
    /*  The blue threshold is the font units distance under   */
    /*  which overshoots are suppressed due to the BlueShift  */
    /*  even if the scale is greater than BlueScale.          */
    /*                                                        */
    /*  It is the smallest distance such that                 */
    /*                                                        */
    /*    dist <= BlueShift && dist*scale <= 0.5 pixels       */
    /*                                                        */
    {
      FT_Int  threshold = blues->blue_shift;


      while ( threshold > 0 && FT_MulFix( threshold, scale ) > 32 )
        threshold--;

      blues->blue_threshold = threshold;
    }

    for ( num = 0; num < 4; num++ )
    {
      PSH_Blue_Zone  zone;


      switch ( num )
      {
      case 0:
        table = &blues->normal_top;
        break;
      case 1:
        table = &blues->normal_bottom;
        break;
      case 2:
        table = &blues->family_top;
        break;
      default:
        table = &blues->family_bottom;
        break;
      }

      zone  = table->zones;
      count = table->count;
      for ( ; count > 0; count--, zone++ )
      {
        zone->cur_top    = FT_MulFix( zone->org_top,    scale ) + delta;
        zone->cur_bottom = FT_MulFix( zone->org_bottom, scale ) + delta;
        zone->cur_ref    = FT_MulFix( zone->org_ref,    scale ) + delta;
        zone->cur_delta  = FT_MulFix( zone->org_delta,  scale );

        /* round scaled reference position */
        zone->cur_ref = FT_PIX_ROUND( zone->cur_ref );

#if 0
        if ( zone->cur_ref > zone->cur_top )
          zone->cur_ref -= 64;
        else if ( zone->cur_ref < zone->cur_bottom )
          zone->cur_ref += 64;
#endif
      }
    }

    /* process the families now */

    for ( num = 0; num < 2; num++ )
    {
      PSH_Blue_Zone   zone1, zone2;
      FT_UInt         count1, count2;
      PSH_Blue_Table  normal, family;


      switch ( num )
      {
      case 0:
        normal = &blues->normal_top;
        family = &blues->family_top;
        break;

      default:
        normal = &blues->normal_bottom;
        family = &blues->family_bottom;
      }

      zone1  = normal->zones;
      count1 = normal->count;

      for ( ; count1 > 0; count1--, zone1++ )
      {
        /* try to find a family zone whose reference position is less */
        /* than 1 pixel far from the current zone                     */
        zone2  = family->zones;
        count2 = family->count;

        for ( ; count2 > 0; count2--, zone2++ )
        {
          FT_Pos  Delta;


          Delta = zone1->org_ref - zone2->org_ref;
          if ( Delta < 0 )
            Delta = -Delta;

          if ( FT_MulFix( Delta, scale ) < 64 )
          {
            zone1->cur_top    = zone2->cur_top;
            zone1->cur_bottom = zone2->cur_bottom;
            zone1->cur_ref    = zone2->cur_ref;
            zone1->cur_delta  = zone2->cur_delta;
            break;
          }
        }
      }
    }
  }


  /* calculate the maximum height of given blue zones */
  static FT_Short
  psh_calc_max_height( FT_UInt          num,
                       const FT_Short*  values,
                       FT_Short         cur_max )
  {
    FT_UInt  count;


    for ( count = 0; count < num; count += 2 )
    {
      FT_Short  cur_height = values[count + 1] - values[count];


      if ( cur_height > cur_max )
        cur_max = cur_height;
    }

    return cur_max;
  }


  FT_LOCAL_DEF( void )
  psh_blues_snap_stem( PSH_Blues      blues,
                       FT_Int         stem_top,
                       FT_Int         stem_bot,
                       PSH_Alignment  alignment )
  {
    PSH_Blue_Table  table;
    FT_UInt         count;
    FT_Pos          delta;
    PSH_Blue_Zone   zone;
    FT_Int          no_shoots;


    alignment->align = PSH_BLUE_ALIGN_NONE;

    no_shoots = blues->no_overshoots;

    /* look up stem top in top zones table */
    table = &blues->normal_top;
    count = table->count;
    zone  = table->zones;

    for ( ; count > 0; count--, zone++ )
    {
      delta = stem_top - zone->org_bottom;
      if ( delta < -blues->blue_fuzz )
        break;

      if ( stem_top <= zone->org_top + blues->blue_fuzz )
      {
        if ( no_shoots || delta <= blues->blue_threshold )
        {
          alignment->align    |= PSH_BLUE_ALIGN_TOP;
          alignment->align_top = zone->cur_ref;
        }
        break;
      }
    }

    /* look up stem bottom in bottom zones table */
    table = &blues->normal_bottom;
    count = table->count;
    zone  = table->zones + count-1;

    for ( ; count > 0; count--, zone-- )
    {
      delta = zone->org_top - stem_bot;
      if ( delta < -blues->blue_fuzz )
        break;

      if ( stem_bot >= zone->org_bottom - blues->blue_fuzz )
      {
        if ( no_shoots || delta < blues->blue_threshold )
        {
          alignment->align    |= PSH_BLUE_ALIGN_BOT;
          alignment->align_bot = zone->cur_ref;
        }
        break;
      }
    }
  }


  /*************************************************************************/
  /*************************************************************************/
  /*****                                                               *****/
  /*****                        GLOBAL HINTS                           *****/
  /*****                                                               *****/
  /*************************************************************************/
  /*************************************************************************/

  static void
  psh_globals_destroy( PSH_Globals  globals )
  {
    if ( globals )
    {
      FT_Memory  memory;


      memory = globals->memory;
      globals->dimension[0].stdw.count = 0;
      globals->dimension[1].stdw.count = 0;

      globals->blues.normal_top.count    = 0;
      globals->blues.normal_bottom.count = 0;
      globals->blues.family_top.count    = 0;
      globals->blues.family_bottom.count = 0;

      FT_FREE( globals );

#ifdef DEBUG_HINTER
      ps_debug_globals = 0;
#endif
    }
  }


  static FT_Error
  psh_globals_new( FT_Memory     memory,
                   T1_Private*   priv,
                   PSH_Globals  *aglobals )
  {
    PSH_Globals  globals = NULL;
    FT_Error     error;


    if ( !FT_NEW( globals ) )
    {
      FT_UInt    count;
      FT_Short*  read;


      globals->memory = memory;

      /* copy standard widths */
      {
        PSH_Dimension  dim   = &globals->dimension[1];
        PSH_Width      write = dim->stdw.widths;


        write->org = priv->standard_width[0];
        write++;

        read = priv->snap_widths;
        for ( count = priv->num_snap_widths; count > 0; count-- )
        {
          write->org = *read;
          write++;
          read++;
        }

        dim->stdw.count = priv->num_snap_widths + 1;
      }

      /* copy standard heights */
      {
        PSH_Dimension  dim = &globals->dimension[0];
        PSH_Width      write = dim->stdw.widths;


        write->org = priv->standard_height[0];
        write++;
        read = priv->snap_heights;
        for ( count = priv->num_snap_heights; count > 0; count-- )
        {
          write->org = *read;
          write++;
          read++;
        }

        dim->stdw.count = priv->num_snap_heights + 1;
      }

      /* copy blue zones */
      psh_blues_set_zones( &globals->blues, priv->num_blue_values,
                           priv->blue_values, priv->num_other_blues,
                           priv->other_blues, priv->blue_fuzz, 0 );

      psh_blues_set_zones( &globals->blues, priv->num_family_blues,
                           priv->family_blues, priv->num_family_other_blues,
                           priv->family_other_blues, priv->blue_fuzz, 1 );

      /* limit the BlueScale value to `1 / max_of_blue_zone_heights' */
      {
        FT_Fixed  max_scale;
        FT_Short  max_height = 1;


        max_height = psh_calc_max_height( priv->num_blue_values,
                                          priv->blue_values,
                                          max_height );
        max_height = psh_calc_max_height( priv->num_other_blues,
                                          priv->other_blues,
                                          max_height );
        max_height = psh_calc_max_height( priv->num_family_blues,
                                          priv->family_blues,
                                          max_height );
        max_height = psh_calc_max_height( priv->num_family_other_blues,
                                          priv->family_other_blues,
                                          max_height );

        /* BlueScale is scaled 1000 times */
        max_scale = FT_DivFix( 1000, max_height );
        globals->blues.blue_scale = priv->blue_scale < max_scale
                                      ? priv->blue_scale
                                      : max_scale;
      }

      globals->blues.blue_shift = priv->blue_shift;
      globals->blues.blue_fuzz  = priv->blue_fuzz;

      globals->dimension[0].scale_mult  = 0;
      globals->dimension[0].scale_delta = 0;
      globals->dimension[1].scale_mult  = 0;
      globals->dimension[1].scale_delta = 0;

#ifdef DEBUG_HINTER
      ps_debug_globals = globals;
#endif
    }

    *aglobals = globals;
    return error;
  }


  FT_LOCAL_DEF( FT_Error )
  psh_globals_set_scale( PSH_Globals  globals,
                         FT_Fixed     x_scale,
                         FT_Fixed     y_scale,
                         FT_Fixed     x_delta,
                         FT_Fixed     y_delta )
  {
    PSH_Dimension  dim = &globals->dimension[0];


    dim = &globals->dimension[0];
    if ( x_scale != dim->scale_mult  ||
         x_delta != dim->scale_delta )
    {
      dim->scale_mult  = x_scale;
      dim->scale_delta = x_delta;

      psh_globals_scale_widths( globals, 0 );
    }

    dim = &globals->dimension[1];
    if ( y_scale != dim->scale_mult  ||
         y_delta != dim->scale_delta )
    {
      dim->scale_mult  = y_scale;
      dim->scale_delta = y_delta;

      psh_globals_scale_widths( globals, 1 );
      psh_blues_scale_zones( &globals->blues, y_scale, y_delta );
    }

    return 0;
  }


  FT_LOCAL_DEF( void )
  psh_globals_funcs_init( PSH_Globals_FuncsRec*  funcs )
  {
    funcs->create    = psh_globals_new;
    funcs->set_scale = psh_globals_set_scale;
    funcs->destroy   = psh_globals_destroy;
  }


/* END */