XFA: merge patch from CL 815103002
[pdfium.git] / third_party / freetype / src / pshinter / pshglob.c
1 /***************************************************************************/
2 /*                                                                         */
3 /*  pshglob.c                                                              */
4 /*                                                                         */
5 /*    PostScript hinter global hinting management (body).                  */
6 /*    Inspired by the new auto-hinter module.                              */
7 /*                                                                         */
8 /*  Copyright 2001-2004, 2006, 2010, 2012-2014 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   /* calculate the maximum height of given blue zones */
526   static FT_Short
527   psh_calc_max_height( FT_UInt          num,
528                        const FT_Short*  values,
529                        FT_Short         cur_max )
530   {
531     FT_UInt  count;
532
533
534     for ( count = 0; count < num; count += 2 )
535     {
536       FT_Short  cur_height = values[count + 1] - values[count];
537
538
539       if ( cur_height > cur_max )
540         cur_max = cur_height;
541     }
542
543     return cur_max;
544   }
545
546
547   FT_LOCAL_DEF( void )
548   psh_blues_snap_stem( PSH_Blues      blues,
549                        FT_Int         stem_top,
550                        FT_Int         stem_bot,
551                        PSH_Alignment  alignment )
552   {
553     PSH_Blue_Table  table;
554     FT_UInt         count;
555     FT_Pos          delta;
556     PSH_Blue_Zone   zone;
557     FT_Int          no_shoots;
558
559
560     alignment->align = PSH_BLUE_ALIGN_NONE;
561
562     no_shoots = blues->no_overshoots;
563
564     /* look up stem top in top zones table */
565     table = &blues->normal_top;
566     count = table->count;
567     zone  = table->zones;
568
569     for ( ; count > 0; count--, zone++ )
570     {
571       delta = stem_top - zone->org_bottom;
572       if ( delta < -blues->blue_fuzz )
573         break;
574
575       if ( stem_top <= zone->org_top + blues->blue_fuzz )
576       {
577         if ( no_shoots || delta <= blues->blue_threshold )
578         {
579           alignment->align    |= PSH_BLUE_ALIGN_TOP;
580           alignment->align_top = zone->cur_ref;
581         }
582         break;
583       }
584     }
585
586     /* look up stem bottom in bottom zones table */
587     table = &blues->normal_bottom;
588     count = table->count;
589     zone  = table->zones + count-1;
590
591     for ( ; count > 0; count--, zone-- )
592     {
593       delta = zone->org_top - stem_bot;
594       if ( delta < -blues->blue_fuzz )
595         break;
596
597       if ( stem_bot >= zone->org_bottom - blues->blue_fuzz )
598       {
599         if ( no_shoots || delta < blues->blue_threshold )
600         {
601           alignment->align    |= PSH_BLUE_ALIGN_BOT;
602           alignment->align_bot = zone->cur_ref;
603         }
604         break;
605       }
606     }
607   }
608
609
610   /*************************************************************************/
611   /*************************************************************************/
612   /*****                                                               *****/
613   /*****                        GLOBAL HINTS                           *****/
614   /*****                                                               *****/
615   /*************************************************************************/
616   /*************************************************************************/
617
618   static void
619   psh_globals_destroy( PSH_Globals  globals )
620   {
621     if ( globals )
622     {
623       FT_Memory  memory;
624
625
626       memory = globals->memory;
627       globals->dimension[0].stdw.count = 0;
628       globals->dimension[1].stdw.count = 0;
629
630       globals->blues.normal_top.count    = 0;
631       globals->blues.normal_bottom.count = 0;
632       globals->blues.family_top.count    = 0;
633       globals->blues.family_bottom.count = 0;
634
635       FT_FREE( globals );
636
637 #ifdef DEBUG_HINTER
638       ps_debug_globals = 0;
639 #endif
640     }
641   }
642
643
644   static FT_Error
645   psh_globals_new( FT_Memory     memory,
646                    T1_Private*   priv,
647                    PSH_Globals  *aglobals )
648   {
649     PSH_Globals  globals = NULL;
650     FT_Error     error;
651
652
653     if ( !FT_NEW( globals ) )
654     {
655       FT_UInt    count;
656       FT_Short*  read;
657
658
659       globals->memory = memory;
660
661       /* copy standard widths */
662       {
663         PSH_Dimension  dim   = &globals->dimension[1];
664         PSH_Width      write = dim->stdw.widths;
665
666
667         write->org = priv->standard_width[0];
668         write++;
669
670         read = priv->snap_widths;
671         for ( count = priv->num_snap_widths; count > 0; count-- )
672         {
673           write->org = *read;
674           write++;
675           read++;
676         }
677
678         dim->stdw.count = priv->num_snap_widths + 1;
679       }
680
681       /* copy standard heights */
682       {
683         PSH_Dimension  dim = &globals->dimension[0];
684         PSH_Width      write = dim->stdw.widths;
685
686
687         write->org = priv->standard_height[0];
688         write++;
689         read = priv->snap_heights;
690         for ( count = priv->num_snap_heights; count > 0; count-- )
691         {
692           write->org = *read;
693           write++;
694           read++;
695         }
696
697         dim->stdw.count = priv->num_snap_heights + 1;
698       }
699
700       /* copy blue zones */
701       psh_blues_set_zones( &globals->blues, priv->num_blue_values,
702                            priv->blue_values, priv->num_other_blues,
703                            priv->other_blues, priv->blue_fuzz, 0 );
704
705       psh_blues_set_zones( &globals->blues, priv->num_family_blues,
706                            priv->family_blues, priv->num_family_other_blues,
707                            priv->family_other_blues, priv->blue_fuzz, 1 );
708
709       /* limit the BlueScale value to `1 / max_of_blue_zone_heights' */
710       {
711         FT_Fixed  max_scale;
712         FT_Short  max_height = 1;
713
714
715         max_height = psh_calc_max_height( priv->num_blue_values,
716                                           priv->blue_values,
717                                           max_height );
718         max_height = psh_calc_max_height( priv->num_other_blues,
719                                           priv->other_blues,
720                                           max_height );
721         max_height = psh_calc_max_height( priv->num_family_blues,
722                                           priv->family_blues,
723                                           max_height );
724         max_height = psh_calc_max_height( priv->num_family_other_blues,
725                                           priv->family_other_blues,
726                                           max_height );
727
728         /* BlueScale is scaled 1000 times */
729         max_scale = FT_DivFix( 1000, max_height );
730         globals->blues.blue_scale = priv->blue_scale < max_scale
731                                       ? priv->blue_scale
732                                       : max_scale;
733       }
734
735       globals->blues.blue_shift = priv->blue_shift;
736       globals->blues.blue_fuzz  = priv->blue_fuzz;
737
738       globals->dimension[0].scale_mult  = 0;
739       globals->dimension[0].scale_delta = 0;
740       globals->dimension[1].scale_mult  = 0;
741       globals->dimension[1].scale_delta = 0;
742
743 #ifdef DEBUG_HINTER
744       ps_debug_globals = globals;
745 #endif
746     }
747
748     *aglobals = globals;
749     return error;
750   }
751
752
753   FT_LOCAL_DEF( void )
754   psh_globals_set_scale( PSH_Globals  globals,
755                          FT_Fixed     x_scale,
756                          FT_Fixed     y_scale,
757                          FT_Fixed     x_delta,
758                          FT_Fixed     y_delta )
759   {
760     PSH_Dimension  dim;
761
762
763     dim = &globals->dimension[0];
764     if ( x_scale != dim->scale_mult  ||
765          x_delta != dim->scale_delta )
766     {
767       dim->scale_mult  = x_scale;
768       dim->scale_delta = x_delta;
769
770       psh_globals_scale_widths( globals, 0 );
771     }
772
773     dim = &globals->dimension[1];
774     if ( y_scale != dim->scale_mult  ||
775          y_delta != dim->scale_delta )
776     {
777       dim->scale_mult  = y_scale;
778       dim->scale_delta = y_delta;
779
780       psh_globals_scale_widths( globals, 1 );
781       psh_blues_scale_zones( &globals->blues, y_scale, y_delta );
782     }
783   }
784
785
786   FT_LOCAL_DEF( void )
787   psh_globals_funcs_init( PSH_Globals_FuncsRec*  funcs )
788   {
789     funcs->create    = psh_globals_new;
790     funcs->set_scale = psh_globals_set_scale;
791     funcs->destroy   = psh_globals_destroy;
792   }
793
794
795 /* END */