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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
psh_globals_scale_widths(PSH_Globals globals,FT_UInt direction)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
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)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
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)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
psh_blues_scale_zones(PSH_Blues blues,FT_Fixed scale,FT_Pos delta)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 )
psh_blues_snap_stem(PSH_Blues blues,FT_Int stem_top,FT_Int stem_bot,PSH_Alignment alignment)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
psh_globals_destroy(PSH_Globals globals)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
psh_globals_new(FT_Memory memory,T1_Private * priv,PSH_Globals * aglobals)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 )
psh_globals_set_scale(PSH_Globals globals,FT_Fixed x_scale,FT_Fixed y_scale,FT_Fixed x_delta,FT_Fixed y_delta)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 )
psh_globals_funcs_init(PSH_Globals_FuncsRec * funcs)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