1/***************************************************************************/
2/*                                                                         */
3/*  pshglob.c                                                              */
4/*                                                                         */
5/*    PostScript hinter global hinting management (body).                  */
6/*    Inspired by the new auto-hinter module.                              */
7/*                                                                         */
8/*  Copyright 2001, 2002, 2003, 2004, 2006, 2010 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_FREETYPE_H
22#include FT_INTERNAL_OBJECTS_H
23#include "pshglob.h"
24
25#ifdef DEBUG_HINTER
26  PSH_Globals  ps_debug_globals = 0;
27#endif
28
29
30  /*************************************************************************/
31  /*************************************************************************/
32  /*****                                                               *****/
33  /*****                       STANDARD WIDTHS                         *****/
34  /*****                                                               *****/
35  /*************************************************************************/
36  /*************************************************************************/
37
38
39  /* scale the widths/heights table */
40  static void
41  psh_globals_scale_widths( PSH_Globals  globals,
42                            FT_UInt      direction )
43  {
44    PSH_Dimension  dim   = &globals->dimension[direction];
45    PSH_Widths     stdw  = &dim->stdw;
46    FT_UInt        count = stdw->count;
47    PSH_Width      width = stdw->widths;
48    PSH_Width      stand = width;               /* standard width/height */
49    FT_Fixed       scale = dim->scale_mult;
50
51
52    if ( count > 0 )
53    {
54      width->cur = FT_MulFix( width->org, scale );
55      width->fit = FT_PIX_ROUND( width->cur );
56
57      width++;
58      count--;
59
60      for ( ; count > 0; count--, width++ )
61      {
62        FT_Pos  w, dist;
63
64
65        w    = FT_MulFix( width->org, scale );
66        dist = w - stand->cur;
67
68        if ( dist < 0 )
69          dist = -dist;
70
71        if ( dist < 128 )
72          w = stand->cur;
73
74        width->cur = w;
75        width->fit = FT_PIX_ROUND( w );
76      }
77    }
78  }
79
80
81#if 0
82
83  /* org_width is is font units, result in device pixels, 26.6 format */
84  FT_LOCAL_DEF( FT_Pos )
85  psh_dimension_snap_width( PSH_Dimension  dimension,
86                            FT_Int         org_width )
87  {
88    FT_UInt  n;
89    FT_Pos   width     = FT_MulFix( org_width, dimension->scale_mult );
90    FT_Pos   best      = 64 + 32 + 2;
91    FT_Pos   reference = width;
92
93
94    for ( n = 0; n < dimension->stdw.count; n++ )
95    {
96      FT_Pos  w;
97      FT_Pos  dist;
98
99
100      w = dimension->stdw.widths[n].cur;
101      dist = width - w;
102      if ( dist < 0 )
103        dist = -dist;
104      if ( dist < best )
105      {
106        best      = dist;
107        reference = w;
108      }
109    }
110
111    if ( width >= reference )
112    {
113      width -= 0x21;
114      if ( width < reference )
115        width = reference;
116    }
117    else
118    {
119      width += 0x21;
120      if ( width > reference )
121        width = reference;
122    }
123
124    return width;
125  }
126
127#endif /* 0 */
128
129
130  /*************************************************************************/
131  /*************************************************************************/
132  /*****                                                               *****/
133  /*****                       BLUE ZONES                              *****/
134  /*****                                                               *****/
135  /*************************************************************************/
136  /*************************************************************************/
137
138  static void
139  psh_blues_set_zones_0( PSH_Blues       target,
140                         FT_Bool         is_others,
141                         FT_UInt         read_count,
142                         FT_Short*       read,
143                         PSH_Blue_Table  top_table,
144                         PSH_Blue_Table  bot_table )
145  {
146    FT_UInt  count_top = top_table->count;
147    FT_UInt  count_bot = bot_table->count;
148    FT_Bool  first     = 1;
149
150    FT_UNUSED( target );
151
152
153    for ( ; read_count > 1; read_count -= 2 )
154    {
155      FT_Int         reference, delta;
156      FT_UInt        count;
157      PSH_Blue_Zone  zones, zone;
158      FT_Bool        top;
159
160
161      /* read blue zone entry, and select target top/bottom zone */
162      top = 0;
163      if ( first || is_others )
164      {
165        reference = read[1];
166        delta     = read[0] - reference;
167
168        zones = bot_table->zones;
169        count = count_bot;
170        first = 0;
171      }
172      else
173      {
174        reference = read[0];
175        delta     = read[1] - reference;
176
177        zones = top_table->zones;
178        count = count_top;
179        top   = 1;
180      }
181
182      /* insert into sorted table */
183      zone = zones;
184      for ( ; count > 0; count--, zone++ )
185      {
186        if ( reference < zone->org_ref )
187          break;
188
189        if ( reference == zone->org_ref )
190        {
191          FT_Int  delta0 = zone->org_delta;
192
193
194          /* we have two zones on the same reference position -- */
195          /* only keep the largest one                           */
196          if ( delta < 0 )
197          {
198            if ( delta < delta0 )
199              zone->org_delta = delta;
200          }
201          else
202          {
203            if ( delta > delta0 )
204              zone->org_delta = delta;
205          }
206          goto Skip;
207        }
208      }
209
210      for ( ; count > 0; count-- )
211        zone[count] = zone[count-1];
212
213      zone->org_ref   = reference;
214      zone->org_delta = delta;
215
216      if ( top )
217        count_top++;
218      else
219        count_bot++;
220
221    Skip:
222      read += 2;
223    }
224
225    top_table->count = count_top;
226    bot_table->count = count_bot;
227  }
228
229
230  /* Re-read blue zones from the original fonts and store them into out */
231  /* private structure.  This function re-orders, sanitizes and         */
232  /* fuzz-expands the zones as well.                                    */
233  static void
234  psh_blues_set_zones( PSH_Blues  target,
235                       FT_UInt    count,
236                       FT_Short*  blues,
237                       FT_UInt    count_others,
238                       FT_Short*  other_blues,
239                       FT_Int     fuzz,
240                       FT_Int     family )
241  {
242    PSH_Blue_Table  top_table, bot_table;
243    FT_Int          count_top, count_bot;
244
245
246    if ( family )
247    {
248      top_table = &target->family_top;
249      bot_table = &target->family_bottom;
250    }
251    else
252    {
253      top_table = &target->normal_top;
254      bot_table = &target->normal_bottom;
255    }
256
257    /* read the input blue zones, and build two sorted tables  */
258    /* (one for the top zones, the other for the bottom zones) */
259    top_table->count = 0;
260    bot_table->count = 0;
261
262    /* first, the blues */
263    psh_blues_set_zones_0( target, 0,
264                           count, blues, top_table, bot_table );
265    psh_blues_set_zones_0( target, 1,
266                           count_others, other_blues, top_table, bot_table );
267
268    count_top = top_table->count;
269    count_bot = bot_table->count;
270
271    /* sanitize top table */
272    if ( count_top > 0 )
273    {
274      PSH_Blue_Zone  zone = top_table->zones;
275
276
277      for ( count = count_top; count > 0; count--, zone++ )
278      {
279        FT_Int  delta;
280
281
282        if ( count > 1 )
283        {
284          delta = zone[1].org_ref - zone[0].org_ref;
285          if ( zone->org_delta > delta )
286            zone->org_delta = delta;
287        }
288
289        zone->org_bottom = zone->org_ref;
290        zone->org_top    = zone->org_delta + zone->org_ref;
291      }
292    }
293
294    /* sanitize bottom table */
295    if ( count_bot > 0 )
296    {
297      PSH_Blue_Zone  zone = bot_table->zones;
298
299
300      for ( count = count_bot; count > 0; count--, zone++ )
301      {
302        FT_Int  delta;
303
304
305        if ( count > 1 )
306        {
307          delta = zone[0].org_ref - zone[1].org_ref;
308          if ( zone->org_delta < delta )
309            zone->org_delta = delta;
310        }
311
312        zone->org_top    = zone->org_ref;
313        zone->org_bottom = zone->org_delta + zone->org_ref;
314      }
315    }
316
317    /* expand top and bottom tables with blue fuzz */
318    {
319      FT_Int         dim, top, bot, delta;
320      PSH_Blue_Zone  zone;
321
322
323      zone  = top_table->zones;
324      count = count_top;
325
326      for ( dim = 1; dim >= 0; dim-- )
327      {
328        if ( count > 0 )
329        {
330          /* expand the bottom of the lowest zone normally */
331          zone->org_bottom -= fuzz;
332
333          /* expand the top and bottom of intermediate zones;    */
334          /* checking that the interval is smaller than the fuzz */
335          top = zone->org_top;
336
337          for ( count--; count > 0; count-- )
338          {
339            bot   = zone[1].org_bottom;
340            delta = bot - top;
341
342            if ( delta < 2 * fuzz )
343              zone[0].org_top = zone[1].org_bottom = top + delta / 2;
344            else
345            {
346              zone[0].org_top    = top + fuzz;
347              zone[1].org_bottom = bot - fuzz;
348            }
349
350            zone++;
351            top = zone->org_top;
352          }
353
354          /* expand the top of the highest zone normally */
355          zone->org_top = top + fuzz;
356        }
357        zone  = bot_table->zones;
358        count = count_bot;
359      }
360    }
361  }
362
363
364  /* reset the blues table when the device transform changes */
365  static void
366  psh_blues_scale_zones( PSH_Blues  blues,
367                         FT_Fixed   scale,
368                         FT_Pos     delta )
369  {
370    FT_UInt         count;
371    FT_UInt         num;
372    PSH_Blue_Table  table = 0;
373
374    /*                                                        */
375    /* Determine whether we need to suppress overshoots or    */
376    /* not.  We simply need to compare the vertical scale     */
377    /* parameter to the raw bluescale value.  Here is why:    */
378    /*                                                        */
379    /*   We need to suppress overshoots for all pointsizes.   */
380    /*   At 300dpi that satisfies:                            */
381    /*                                                        */
382    /*      pointsize < 240*bluescale + 0.49                  */
383    /*                                                        */
384    /*   This corresponds to:                                 */
385    /*                                                        */
386    /*      pixelsize < 1000*bluescale + 49/24                */
387    /*                                                        */
388    /*      scale*EM_Size < 1000*bluescale + 49/24            */
389    /*                                                        */
390    /*   However, for normal Type 1 fonts, EM_Size is 1000!   */
391    /*   We thus only check:                                  */
392    /*                                                        */
393    /*      scale < bluescale + 49/24000                      */
394    /*                                                        */
395    /*   which we shorten to                                  */
396    /*                                                        */
397    /*      "scale < bluescale"                               */
398    /*                                                        */
399    /* Note that `blue_scale' is stored 1000 times its real   */
400    /* value, and that `scale' converts from font units to    */
401    /* fractional pixels.                                     */
402    /*                                                        */
403
404    /* 1000 / 64 = 125 / 8 */
405    if ( scale >= 0x20C49BAL )
406      blues->no_overshoots = FT_BOOL( scale < blues->blue_scale * 8 / 125 );
407    else
408      blues->no_overshoots = FT_BOOL( scale * 125 < blues->blue_scale * 8 );
409
410    /*                                                        */
411    /*  The blue threshold is the font units distance under   */
412    /*  which overshoots are suppressed due to the BlueShift  */
413    /*  even if the scale is greater than BlueScale.          */
414    /*                                                        */
415    /*  It is the smallest distance such that                 */
416    /*                                                        */
417    /*    dist <= BlueShift && dist*scale <= 0.5 pixels       */
418    /*                                                        */
419    {
420      FT_Int  threshold = blues->blue_shift;
421
422
423      while ( threshold > 0 && FT_MulFix( threshold, scale ) > 32 )
424        threshold--;
425
426      blues->blue_threshold = threshold;
427    }
428
429    for ( num = 0; num < 4; num++ )
430    {
431      PSH_Blue_Zone  zone;
432
433
434      switch ( num )
435      {
436      case 0:
437        table = &blues->normal_top;
438        break;
439      case 1:
440        table = &blues->normal_bottom;
441        break;
442      case 2:
443        table = &blues->family_top;
444        break;
445      default:
446        table = &blues->family_bottom;
447        break;
448      }
449
450      zone  = table->zones;
451      count = table->count;
452      for ( ; count > 0; count--, zone++ )
453      {
454        zone->cur_top    = FT_MulFix( zone->org_top,    scale ) + delta;
455        zone->cur_bottom = FT_MulFix( zone->org_bottom, scale ) + delta;
456        zone->cur_ref    = FT_MulFix( zone->org_ref,    scale ) + delta;
457        zone->cur_delta  = FT_MulFix( zone->org_delta,  scale );
458
459        /* round scaled reference position */
460        zone->cur_ref = FT_PIX_ROUND( zone->cur_ref );
461
462#if 0
463        if ( zone->cur_ref > zone->cur_top )
464          zone->cur_ref -= 64;
465        else if ( zone->cur_ref < zone->cur_bottom )
466          zone->cur_ref += 64;
467#endif
468      }
469    }
470
471    /* process the families now */
472
473    for ( num = 0; num < 2; num++ )
474    {
475      PSH_Blue_Zone   zone1, zone2;
476      FT_UInt         count1, count2;
477      PSH_Blue_Table  normal, family;
478
479
480      switch ( num )
481      {
482      case 0:
483        normal = &blues->normal_top;
484        family = &blues->family_top;
485        break;
486
487      default:
488        normal = &blues->normal_bottom;
489        family = &blues->family_bottom;
490      }
491
492      zone1  = normal->zones;
493      count1 = normal->count;
494
495      for ( ; count1 > 0; count1--, zone1++ )
496      {
497        /* try to find a family zone whose reference position is less */
498        /* than 1 pixel far from the current zone                     */
499        zone2  = family->zones;
500        count2 = family->count;
501
502        for ( ; count2 > 0; count2--, zone2++ )
503        {
504          FT_Pos  Delta;
505
506
507          Delta = zone1->org_ref - zone2->org_ref;
508          if ( Delta < 0 )
509            Delta = -Delta;
510
511          if ( FT_MulFix( Delta, scale ) < 64 )
512          {
513            zone1->cur_top    = zone2->cur_top;
514            zone1->cur_bottom = zone2->cur_bottom;
515            zone1->cur_ref    = zone2->cur_ref;
516            zone1->cur_delta  = zone2->cur_delta;
517            break;
518          }
519        }
520      }
521    }
522  }
523
524
525  FT_LOCAL_DEF( void )
526  psh_blues_snap_stem( PSH_Blues      blues,
527                       FT_Int         stem_top,
528                       FT_Int         stem_bot,
529                       PSH_Alignment  alignment )
530  {
531    PSH_Blue_Table  table;
532    FT_UInt         count;
533    FT_Pos          delta;
534    PSH_Blue_Zone   zone;
535    FT_Int          no_shoots;
536
537
538    alignment->align = PSH_BLUE_ALIGN_NONE;
539
540    no_shoots = blues->no_overshoots;
541
542    /* look up stem top in top zones table */
543    table = &blues->normal_top;
544    count = table->count;
545    zone  = table->zones;
546
547    for ( ; count > 0; count--, zone++ )
548    {
549      delta = stem_top - zone->org_bottom;
550      if ( delta < -blues->blue_fuzz )
551        break;
552
553      if ( stem_top <= zone->org_top + blues->blue_fuzz )
554      {
555        if ( no_shoots || delta <= blues->blue_threshold )
556        {
557          alignment->align    |= PSH_BLUE_ALIGN_TOP;
558          alignment->align_top = zone->cur_ref;
559        }
560        break;
561      }
562    }
563
564    /* look up stem bottom in bottom zones table */
565    table = &blues->normal_bottom;
566    count = table->count;
567    zone  = table->zones + count-1;
568
569    for ( ; count > 0; count--, zone-- )
570    {
571      delta = zone->org_top - stem_bot;
572      if ( delta < -blues->blue_fuzz )
573        break;
574
575      if ( stem_bot >= zone->org_bottom - blues->blue_fuzz )
576      {
577        if ( no_shoots || delta < blues->blue_threshold )
578        {
579          alignment->align    |= PSH_BLUE_ALIGN_BOT;
580          alignment->align_bot = zone->cur_ref;
581        }
582        break;
583      }
584    }
585  }
586
587
588  /*************************************************************************/
589  /*************************************************************************/
590  /*****                                                               *****/
591  /*****                        GLOBAL HINTS                           *****/
592  /*****                                                               *****/
593  /*************************************************************************/
594  /*************************************************************************/
595
596  static void
597  psh_globals_destroy( PSH_Globals  globals )
598  {
599    if ( globals )
600    {
601      FT_Memory  memory;
602
603
604      memory = globals->memory;
605      globals->dimension[0].stdw.count = 0;
606      globals->dimension[1].stdw.count = 0;
607
608      globals->blues.normal_top.count    = 0;
609      globals->blues.normal_bottom.count = 0;
610      globals->blues.family_top.count    = 0;
611      globals->blues.family_bottom.count = 0;
612
613      FT_FREE( globals );
614
615#ifdef DEBUG_HINTER
616      ps_debug_globals = 0;
617#endif
618    }
619  }
620
621
622  static FT_Error
623  psh_globals_new( FT_Memory     memory,
624                   T1_Private*   priv,
625                   PSH_Globals  *aglobals )
626  {
627    PSH_Globals  globals = NULL;
628    FT_Error     error;
629
630
631    if ( !FT_NEW( globals ) )
632    {
633      FT_UInt    count;
634      FT_Short*  read;
635
636
637      globals->memory = memory;
638
639      /* copy standard widths */
640      {
641        PSH_Dimension  dim   = &globals->dimension[1];
642        PSH_Width      write = dim->stdw.widths;
643
644
645        write->org = priv->standard_width[0];
646        write++;
647
648        read = priv->snap_widths;
649        for ( count = priv->num_snap_widths; count > 0; count-- )
650        {
651          write->org = *read;
652          write++;
653          read++;
654        }
655
656        dim->stdw.count = priv->num_snap_widths + 1;
657      }
658
659      /* copy standard heights */
660      {
661        PSH_Dimension  dim = &globals->dimension[0];
662        PSH_Width      write = dim->stdw.widths;
663
664
665        write->org = priv->standard_height[0];
666        write++;
667        read = priv->snap_heights;
668        for ( count = priv->num_snap_heights; count > 0; count-- )
669        {
670          write->org = *read;
671          write++;
672          read++;
673        }
674
675        dim->stdw.count = priv->num_snap_heights + 1;
676      }
677
678      /* copy blue zones */
679      psh_blues_set_zones( &globals->blues, priv->num_blue_values,
680                           priv->blue_values, priv->num_other_blues,
681                           priv->other_blues, priv->blue_fuzz, 0 );
682
683      psh_blues_set_zones( &globals->blues, priv->num_family_blues,
684                           priv->family_blues, priv->num_family_other_blues,
685                           priv->family_other_blues, priv->blue_fuzz, 1 );
686
687      globals->blues.blue_scale = priv->blue_scale;
688      globals->blues.blue_shift = priv->blue_shift;
689      globals->blues.blue_fuzz  = priv->blue_fuzz;
690
691      globals->dimension[0].scale_mult  = 0;
692      globals->dimension[0].scale_delta = 0;
693      globals->dimension[1].scale_mult  = 0;
694      globals->dimension[1].scale_delta = 0;
695
696#ifdef DEBUG_HINTER
697      ps_debug_globals = globals;
698#endif
699    }
700
701    *aglobals = globals;
702    return error;
703  }
704
705
706  FT_LOCAL_DEF( FT_Error )
707  psh_globals_set_scale( PSH_Globals  globals,
708                         FT_Fixed     x_scale,
709                         FT_Fixed     y_scale,
710                         FT_Fixed     x_delta,
711                         FT_Fixed     y_delta )
712  {
713    PSH_Dimension  dim = &globals->dimension[0];
714
715
716    dim = &globals->dimension[0];
717    if ( x_scale != dim->scale_mult  ||
718         x_delta != dim->scale_delta )
719    {
720      dim->scale_mult  = x_scale;
721      dim->scale_delta = x_delta;
722
723      psh_globals_scale_widths( globals, 0 );
724    }
725
726    dim = &globals->dimension[1];
727    if ( y_scale != dim->scale_mult  ||
728         y_delta != dim->scale_delta )
729    {
730      dim->scale_mult  = y_scale;
731      dim->scale_delta = y_delta;
732
733      psh_globals_scale_widths( globals, 1 );
734      psh_blues_scale_zones( &globals->blues, y_scale, y_delta );
735    }
736
737    return 0;
738  }
739
740
741  FT_LOCAL_DEF( void )
742  psh_globals_funcs_init( PSH_Globals_FuncsRec*  funcs )
743  {
744    funcs->create    = psh_globals_new;
745    funcs->set_scale = psh_globals_set_scale;
746    funcs->destroy   = psh_globals_destroy;
747  }
748
749
750/* END */
751