projects / reactos.git / blob
? search:
summary | shortlog | log | commit | commitdiff | tree
history | raw | HEAD
[CMAKE]
[reactos.git] / lib / 3rdparty / freetype / src / autofit / afcjk.c
1 /***************************************************************************/
2 /* */
3 /* afcjk.c */
4 /* */
5 /* Auto-fitter hinting routines for CJK script (body). */
6 /* */
7 /* Copyright 2006, 2007, 2008, 2009 by */
8 /* David Turner, Robert Wilhelm, and Werner Lemberg. */
9 /* */
10 /* This file is part of the FreeType project, and may only be used, */
11 /* modified, and distributed under the terms of the FreeType project */
12 /* license, LICENSE.TXT. By continuing to use, modify, or distribute */
13 /* this file you indicate that you have read the license and */
14 /* understand and accept it fully. */
15 /* */
16 /***************************************************************************/
17
18 /*
19 * The algorithm is based on akito's autohint patch, available here:
20 *
21 * http://www.kde.gr.jp/~akito/patch/freetype2/
22 *
23 */
24
25 #include "aftypes.h"
26 #include "aflatin.h"
27
28
29 #ifdef AF_CONFIG_OPTION_CJK
30
31 #include "afcjk.h"
32 #include "aferrors.h"
33
34
35 #ifdef AF_USE_WARPER
36 #include "afwarp.h"
37 #endif
38
39
40 /*************************************************************************/
41 /*************************************************************************/
42 /***** *****/
43 /***** C J K G L O B A L M E T R I C S *****/
44 /***** *****/
45 /*************************************************************************/
46 /*************************************************************************/
47
48 FT_LOCAL_DEF( FT_Error )
49 af_cjk_metrics_init( AF_LatinMetrics metrics,
50 FT_Face face )
51 {
52 FT_CharMap oldmap = face->charmap;
53
54
55 metrics->units_per_em = face->units_per_EM;
56
57 /* TODO are there blues? */
58
59 if ( FT_Select_Charmap( face, FT_ENCODING_UNICODE ) )
60 face->charmap = NULL;
61 else
62 {
63 /* latin's version would suffice */
64 af_latin_metrics_init_widths( metrics, face, 0x7530 );
65 af_latin_metrics_check_digits( metrics, face );
66 }
67
68 FT_Set_Charmap( face, oldmap );
69
70 return AF_Err_Ok;
71 }
72
73
74 static void
75 af_cjk_metrics_scale_dim( AF_LatinMetrics metrics,
76 AF_Scaler scaler,
77 AF_Dimension dim )
78 {
79 AF_LatinAxis axis;
80
81
82 axis = &metrics->axis[dim];
83
84 if ( dim == AF_DIMENSION_HORZ )
85 {
86 axis->scale = scaler->x_scale;
87 axis->delta = scaler->x_delta;
88 }
89 else
90 {
91 axis->scale = scaler->y_scale;
92 axis->delta = scaler->y_delta;
93 }
94 }
95
96
97 FT_LOCAL_DEF( void )
98 af_cjk_metrics_scale( AF_LatinMetrics metrics,
99 AF_Scaler scaler )
100 {
101 metrics->root.scaler = *scaler;
102
103 af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
104 af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
105 }
106
107
108 /*************************************************************************/
109 /*************************************************************************/
110 /***** *****/
111 /***** C J K G L Y P H A N A L Y S I S *****/
112 /***** *****/
113 /*************************************************************************/
114 /*************************************************************************/
115
116 static FT_Error
117 af_cjk_hints_compute_segments( AF_GlyphHints hints,
118 AF_Dimension dim )
119 {
120 AF_AxisHints axis = &hints->axis[dim];
121 AF_Segment segments = axis->segments;
122 AF_Segment segment_limit = segments + axis->num_segments;
123 FT_Error error;
124 AF_Segment seg;
125
126
127 error = af_latin_hints_compute_segments( hints, dim );
128 if ( error )
129 return error;
130
131 /* a segment is round if it doesn't have successive */
132 /* on-curve points. */
133 for ( seg = segments; seg < segment_limit; seg++ )
134 {
135 AF_Point pt = seg->first;
136 AF_Point last = seg->last;
137 AF_Flags f0 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL);
138 AF_Flags f1;
139
140
141 seg->flags &= ~AF_EDGE_ROUND;
142
143 for ( ; pt != last; f0 = f1 )
144 {
145 pt = pt->next;
146 f1 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL);
147
148 if ( !f0 && !f1 )
149 break;
150
151 if ( pt == last )
152 seg->flags |= AF_EDGE_ROUND;
153 }
154 }
155
156 return AF_Err_Ok;
157 }
158
159
160 static void
161 af_cjk_hints_link_segments( AF_GlyphHints hints,
162 AF_Dimension dim )
163 {
164 AF_AxisHints axis = &hints->axis[dim];
165 AF_Segment segments = axis->segments;
166 AF_Segment segment_limit = segments + axis->num_segments;
167 AF_Direction major_dir = axis->major_dir;
168 AF_Segment seg1, seg2;
169 FT_Pos len_threshold;
170 FT_Pos dist_threshold;
171
172
173 len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
174
175 dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
176 : hints->y_scale;
177 dist_threshold = FT_DivFix( 64 * 3, dist_threshold );
178
179 /* now compare each segment to the others */
180 for ( seg1 = segments; seg1 < segment_limit; seg1++ )
181 {
182 /* the fake segments are for metrics hinting only */
183 if ( seg1->first == seg1->last )
184 continue;
185
186 if ( seg1->dir != major_dir )
187 continue;
188
189 for ( seg2 = segments; seg2 < segment_limit; seg2++ )
190 if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
191 {
192 FT_Pos dist = seg2->pos - seg1->pos;
193
194
195 if ( dist < 0 )
196 continue;
197
198 {
199 FT_Pos min = seg1->min_coord;
200 FT_Pos max = seg1->max_coord;
201 FT_Pos len;
202
203
204 if ( min < seg2->min_coord )
205 min = seg2->min_coord;
206
207 if ( max > seg2->max_coord )
208 max = seg2->max_coord;
209
210 len = max - min;
211 if ( len >= len_threshold )
212 {
213 if ( dist * 8 < seg1->score * 9 &&
214 ( dist * 8 < seg1->score * 7 || seg1->len < len ) )
215 {
216 seg1->score = dist;
217 seg1->len = len;
218 seg1->link = seg2;
219 }
220
221 if ( dist * 8 < seg2->score * 9 &&
222 ( dist * 8 < seg2->score * 7 || seg2->len < len ) )
223 {
224 seg2->score = dist;
225 seg2->len = len;
226 seg2->link = seg1;
227 }
228 }
229 }
230 }
231 }
232
233 /*
234 * now compute the `serif' segments
235 *
236 * In Hanzi, some strokes are wider on one or both of the ends.
237 * We either identify the stems on the ends as serifs or remove
238 * the linkage, depending on the length of the stems.
239 *
240 */
241
242 {
243 AF_Segment link1, link2;
244
245
246 for ( seg1 = segments; seg1 < segment_limit; seg1++ )
247 {
248 link1 = seg1->link;
249 if ( !link1 || link1->link != seg1 || link1->pos <= seg1->pos )
250 continue;
251
252 if ( seg1->score >= dist_threshold )
253 continue;
254
255 for ( seg2 = segments; seg2 < segment_limit; seg2++ )
256 {
257 if ( seg2->pos > seg1->pos || seg1 == seg2 )
258 continue;
259
260 link2 = seg2->link;
261 if ( !link2 || link2->link != seg2 || link2->pos < link1->pos )
262 continue;
263
264 if ( seg1->pos == seg2->pos && link1->pos == link2->pos )
265 continue;
266
267 if ( seg2->score <= seg1->score || seg1->score * 4 <= seg2->score )
268 continue;
269
270 /* seg2 < seg1 < link1 < link2 */
271
272 if ( seg1->len >= seg2->len * 3 )
273 {
274 AF_Segment seg;
275
276
277 for ( seg = segments; seg < segment_limit; seg++ )
278 {
279 AF_Segment link = seg->link;
280
281
282 if ( link == seg2 )
283 {
284 seg->link = 0;
285 seg->serif = link1;
286 }
287 else if ( link == link2 )
288 {
289 seg->link = 0;
290 seg->serif = seg1;
291 }
292 }
293 }
294 else
295 {
296 seg1->link = link1->link = 0;
297
298 break;
299 }
300 }
301 }
302 }
303
304 for ( seg1 = segments; seg1 < segment_limit; seg1++ )
305 {
306 seg2 = seg1->link;
307
308 if ( seg2 )
309 {
310 seg2->num_linked++;
311 if ( seg2->link != seg1 )
312 {
313 seg1->link = 0;
314
315 if ( seg2->score < dist_threshold || seg1->score < seg2->score * 4 )
316 seg1->serif = seg2->link;
317 else
318 seg2->num_linked--;
319 }
320 }
321 }
322 }
323
324
325 static FT_Error
326 af_cjk_hints_compute_edges( AF_GlyphHints hints,
327 AF_Dimension dim )
328 {
329 AF_AxisHints axis = &hints->axis[dim];
330 FT_Error error = AF_Err_Ok;
331 FT_Memory memory = hints->memory;
332 AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim];
333
334 AF_Segment segments = axis->segments;
335 AF_Segment segment_limit = segments + axis->num_segments;
336 AF_Segment seg;
337
338 FT_Fixed scale;
339 FT_Pos edge_distance_threshold;
340
341
342 axis->num_edges = 0;
343
344 scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
345 : hints->y_scale;
346
347 /*********************************************************************/
348 /* */
349 /* We begin by generating a sorted table of edges for the current */
350 /* direction. To do so, we simply scan each segment and try to find */
351 /* an edge in our table that corresponds to its position. */
352 /* */
353 /* If no edge is found, we create and insert a new edge in the */
354 /* sorted table. Otherwise, we simply add the segment to the edge's */
355 /* list which is then processed in the second step to compute the */
356 /* edge's properties. */
357 /* */
358 /* Note that the edges table is sorted along the segment/edge */
359 /* position. */
360 /* */
361 /*********************************************************************/
362
363 edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
364 scale );
365 if ( edge_distance_threshold > 64 / 4 )
366 edge_distance_threshold = FT_DivFix( 64 / 4, scale );
367 else
368 edge_distance_threshold = laxis->edge_distance_threshold;
369
370 for ( seg = segments; seg < segment_limit; seg++ )
371 {
372 AF_Edge found = 0;
373 FT_Pos best = 0xFFFFU;
374 FT_Int ee;
375
376
377 /* look for an edge corresponding to the segment */
378 for ( ee = 0; ee < axis->num_edges; ee++ )
379 {
380 AF_Edge edge = axis->edges + ee;
381 FT_Pos dist;
382
383
384 if ( edge->dir != seg->dir )
385 continue;
386
387 dist = seg->pos - edge->fpos;
388 if ( dist < 0 )
389 dist = -dist;
390
391 if ( dist < edge_distance_threshold && dist < best )
392 {
393 AF_Segment link = seg->link;
394
395
396 /* check whether all linked segments of the candidate edge */
397 /* can make a single edge. */
398 if ( link )
399 {
400 AF_Segment seg1 = edge->first;
401 AF_Segment link1;
402 FT_Pos dist2 = 0;
403
404
405 do
406 {
407 link1 = seg1->link;
408 if ( link1 )
409 {
410 dist2 = AF_SEGMENT_DIST( link, link1 );
411 if ( dist2 >= edge_distance_threshold )
412 break;
413 }
414
415 } while ( ( seg1 = seg1->edge_next ) != edge->first );
416
417 if ( dist2 >= edge_distance_threshold )
418 continue;
419 }
420
421 best = dist;
422 found = edge;
423 }
424 }
425
426 if ( !found )
427 {
428 AF_Edge edge;
429
430
431 /* insert a new edge in the list and */
432 /* sort according to the position */
433 error = af_axis_hints_new_edge( axis, seg->pos,
434 (AF_Direction)seg->dir,
435 memory, &edge );
436 if ( error )
437 goto Exit;
438
439 /* add the segment to the new edge's list */
440 FT_ZERO( edge );
441
442 edge->first = seg;
443 edge->last = seg;
444 edge->fpos = seg->pos;
445 edge->opos = edge->pos = FT_MulFix( seg->pos, scale );
446 seg->edge_next = seg;
447 edge->dir = seg->dir;
448 }
449 else
450 {
451 /* if an edge was found, simply add the segment to the edge's */
452 /* list */
453 seg->edge_next = found->first;
454 found->last->edge_next = seg;
455 found->last = seg;
456 }
457 }
458
459 /*********************************************************************/
460 /* */
461 /* Good, we now compute each edge's properties according to segments */
462 /* found on its position. Basically, these are as follows. */
463 /* */
464 /* - edge's main direction */
465 /* - stem edge, serif edge or both (which defaults to stem then) */
466 /* - rounded edge, straight or both (which defaults to straight) */
467 /* - link for edge */
468 /* */
469 /*********************************************************************/
470
471 /* first of all, set the `edge' field in each segment -- this is */
472 /* required in order to compute edge links */
473 /* */
474 /* Note that removing this loop and setting the `edge' field of each */
475 /* segment directly in the code above slows down execution speed for */
476 /* some reasons on platforms like the Sun. */
477
478 {
479 AF_Edge edges = axis->edges;
480 AF_Edge edge_limit = edges + axis->num_edges;
481 AF_Edge edge;
482
483
484 for ( edge = edges; edge < edge_limit; edge++ )
485 {
486 seg = edge->first;
487 if ( seg )
488 do
489 {
490 seg->edge = edge;
491 seg = seg->edge_next;
492
493 } while ( seg != edge->first );
494 }
495
496 /* now compute each edge properties */
497 for ( edge = edges; edge < edge_limit; edge++ )
498 {
499 FT_Int is_round = 0; /* does it contain round segments? */
500 FT_Int is_straight = 0; /* does it contain straight segments? */
501
502
503 seg = edge->first;
504
505 do
506 {
507 FT_Bool is_serif;
508
509
510 /* check for roundness of segment */
511 if ( seg->flags & AF_EDGE_ROUND )
512 is_round++;
513 else
514 is_straight++;
515
516 /* check for links -- if seg->serif is set, then seg->link must */
517 /* be ignored */
518 is_serif = (FT_Bool)( seg->serif && seg->serif->edge != edge );
519
520 if ( seg->link || is_serif )
521 {
522 AF_Edge edge2;
523 AF_Segment seg2;
524
525
526 edge2 = edge->link;
527 seg2 = seg->link;
528
529 if ( is_serif )
530 {
531 seg2 = seg->serif;
532 edge2 = edge->serif;
533 }
534
535 if ( edge2 )
536 {
537 FT_Pos edge_delta;
538 FT_Pos seg_delta;
539
540
541 edge_delta = edge->fpos - edge2->fpos;
542 if ( edge_delta < 0 )
543 edge_delta = -edge_delta;
544
545 seg_delta = AF_SEGMENT_DIST( seg, seg2 );
546
547 if ( seg_delta < edge_delta )
548 edge2 = seg2->edge;
549 }
550 else
551 edge2 = seg2->edge;
552
553 if ( is_serif )
554 {
555 edge->serif = edge2;
556 edge2->flags |= AF_EDGE_SERIF;
557 }
558 else
559 edge->link = edge2;
560 }
561
562 seg = seg->edge_next;
563
564 } while ( seg != edge->first );
565
566 /* set the round/straight flags */
567 edge->flags = AF_EDGE_NORMAL;
568
569 if ( is_round > 0 && is_round >= is_straight )
570 edge->flags |= AF_EDGE_ROUND;
571
572 /* get rid of serifs if link is set */
573 /* XXX: This gets rid of many unpleasant artefacts! */
574 /* Example: the `c' in cour.pfa at size 13 */
575
576 if ( edge->serif && edge->link )
577 edge->serif = 0;
578 }
579 }
580
581 Exit:
582 return error;
583 }
584
585
586 static FT_Error
587 af_cjk_hints_detect_features( AF_GlyphHints hints,
588 AF_Dimension dim )
589 {
590 FT_Error error;
591
592
593 error = af_cjk_hints_compute_segments( hints, dim );
594 if ( !error )
595 {
596 af_cjk_hints_link_segments( hints, dim );
597
598 error = af_cjk_hints_compute_edges( hints, dim );
599 }
600 return error;
601 }
602
603
604 FT_LOCAL_DEF( FT_Error )
605 af_cjk_hints_init( AF_GlyphHints hints,
606 AF_LatinMetrics metrics )
607 {
608 FT_Render_Mode mode;
609 FT_UInt32 scaler_flags, other_flags;
610
611
612 af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics );
613
614 /*
615 * correct x_scale and y_scale when needed, since they may have
616 * been modified af_cjk_scale_dim above
617 */
618 hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
619 hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
620 hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
621 hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
622
623 /* compute flags depending on render mode, etc. */
624 mode = metrics->root.scaler.render_mode;
625
626 #ifdef AF_USE_WARPER
627 if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
628 metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
629 #endif
630
631 scaler_flags = hints->scaler_flags;
632 other_flags = 0;
633
634 /*
635 * We snap the width of vertical stems for the monochrome and
636 * horizontal LCD rendering targets only.
637 */
638 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
639 other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
640
641 /*
642 * We snap the width of horizontal stems for the monochrome and
643 * vertical LCD rendering targets only.
644 */
645 if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
646 other_flags |= AF_LATIN_HINTS_VERT_SNAP;
647
648 /*
649 * We adjust stems to full pixels only if we don't use the `light' mode.
650 */
651 if ( mode != FT_RENDER_MODE_LIGHT )
652 other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
653
654 if ( mode == FT_RENDER_MODE_MONO )
655 other_flags |= AF_LATIN_HINTS_MONO;
656
657 scaler_flags |= AF_SCALER_FLAG_NO_ADVANCE;
658
659 hints->scaler_flags = scaler_flags;
660 hints->other_flags = other_flags;
661
662 return 0;
663 }
664
665
666 /*************************************************************************/
667 /*************************************************************************/
668 /***** *****/
669 /***** C J K G L Y P H G R I D - F I T T I N G *****/
670 /***** *****/
671 /*************************************************************************/
672 /*************************************************************************/
673
674 /* snap a given width in scaled coordinates to one of the */
675 /* current standard widths */
676
677 static FT_Pos
678 af_cjk_snap_width( AF_Width widths,
679 FT_Int count,
680 FT_Pos width )
681 {
682 int n;
683 FT_Pos best = 64 + 32 + 2;
684 FT_Pos reference = width;
685 FT_Pos scaled;
686
687
688 for ( n = 0; n < count; n++ )
689 {
690 FT_Pos w;
691 FT_Pos dist;
692
693
694 w = widths[n].cur;
695 dist = width - w;
696 if ( dist < 0 )
697 dist = -dist;
698 if ( dist < best )
699 {
700 best = dist;
701 reference = w;
702 }
703 }
704
705 scaled = FT_PIX_ROUND( reference );
706
707 if ( width >= reference )
708 {
709 if ( width < scaled + 48 )
710 width = reference;
711 }
712 else
713 {
714 if ( width > scaled - 48 )
715 width = reference;
716 }
717
718 return width;
719 }
720
721
722 /* compute the snapped width of a given stem */
723
724 static FT_Pos
725 af_cjk_compute_stem_width( AF_GlyphHints hints,
726 AF_Dimension dim,
727 FT_Pos width,
728 AF_Edge_Flags base_flags,
729 AF_Edge_Flags stem_flags )
730 {
731 AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics;
732 AF_LatinAxis axis = & metrics->axis[dim];
733 FT_Pos dist = width;
734 FT_Int sign = 0;
735 FT_Int vertical = ( dim == AF_DIMENSION_VERT );
736
737 FT_UNUSED( base_flags );
738 FT_UNUSED( stem_flags );
739
740
741 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
742 return width;
743
744 if ( dist < 0 )
745 {
746 dist = -width;
747 sign = 1;
748 }
749
750 if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
751 ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
752 {
753 /* smooth hinting process: very lightly quantize the stem width */
754
755 if ( axis->width_count > 0 )
756 {
757 if ( FT_ABS( dist - axis->widths[0].cur ) < 40 )
758 {
759 dist = axis->widths[0].cur;
760 if ( dist < 48 )
761 dist = 48;
762
763 goto Done_Width;
764 }
765 }
766
767 if ( dist < 54 )
768 dist += ( 54 - dist ) / 2 ;
769 else if ( dist < 3 * 64 )
770 {
771 FT_Pos delta;
772
773
774 delta = dist & 63;
775 dist &= -64;
776
777 if ( delta < 10 )
778 dist += delta;
779 else if ( delta < 22 )
780 dist += 10;
781 else if ( delta < 42 )
782 dist += delta;
783 else if ( delta < 54 )
784 dist += 54;
785 else
786 dist += delta;
787 }
788 }
789 else
790 {
791 /* strong hinting process: snap the stem width to integer pixels */
792
793 dist = af_cjk_snap_width( axis->widths, axis->width_count, dist );
794
795 if ( vertical )
796 {
797 /* in the case of vertical hinting, always round */
798 /* the stem heights to integer pixels */
799
800 if ( dist >= 64 )
801 dist = ( dist + 16 ) & ~63;
802 else
803 dist = 64;
804 }
805 else
806 {
807 if ( AF_LATIN_HINTS_DO_MONO( hints ) )
808 {
809 /* monochrome horizontal hinting: snap widths to integer pixels */
810 /* with a different threshold */
811
812 if ( dist < 64 )
813 dist = 64;
814 else
815 dist = ( dist + 32 ) & ~63;
816 }
817 else
818 {
819 /* for horizontal anti-aliased hinting, we adopt a more subtle */
820 /* approach: we strengthen small stems, round stems whose size */
821 /* is between 1 and 2 pixels to an integer, otherwise nothing */
822
823 if ( dist < 48 )
824 dist = ( dist + 64 ) >> 1;
825
826 else if ( dist < 128 )
827 dist = ( dist + 22 ) & ~63;
828 else
829 /* round otherwise to prevent color fringes in LCD mode */
830 dist = ( dist + 32 ) & ~63;
831 }
832 }
833 }
834
835 Done_Width:
836 if ( sign )
837 dist = -dist;
838
839 return dist;
840 }
841
842
843 /* align one stem edge relative to the previous stem edge */
844
845 static void
846 af_cjk_align_linked_edge( AF_GlyphHints hints,
847 AF_Dimension dim,
848 AF_Edge base_edge,
849 AF_Edge stem_edge )
850 {
851 FT_Pos dist = stem_edge->opos - base_edge->opos;
852
853 FT_Pos fitted_width = af_cjk_compute_stem_width(
854 hints, dim, dist,
855 (AF_Edge_Flags)base_edge->flags,
856 (AF_Edge_Flags)stem_edge->flags );
857
858
859 stem_edge->pos = base_edge->pos + fitted_width;
860 }
861
862
863 static void
864 af_cjk_align_serif_edge( AF_GlyphHints hints,
865 AF_Edge base,
866 AF_Edge serif )
867 {
868 FT_UNUSED( hints );
869
870 serif->pos = base->pos + ( serif->opos - base->opos );
871 }
872
873
874 /*************************************************************************/
875 /*************************************************************************/
876 /*************************************************************************/
877 /**** ****/
878 /**** E D G E H I N T I N G ****/
879 /**** ****/
880 /*************************************************************************/
881 /*************************************************************************/
882 /*************************************************************************/
883
884
885 #define AF_LIGHT_MODE_MAX_HORZ_GAP 9
886 #define AF_LIGHT_MODE_MAX_VERT_GAP 15
887 #define AF_LIGHT_MODE_MAX_DELTA_ABS 14
888
889
890 static FT_Pos
891 af_hint_normal_stem( AF_GlyphHints hints,
892 AF_Edge edge,
893 AF_Edge edge2,
894 FT_Pos anchor,
895 AF_Dimension dim )
896 {
897 FT_Pos org_len, cur_len, org_center;
898 FT_Pos cur_pos1, cur_pos2;
899 FT_Pos d_off1, u_off1, d_off2, u_off2, delta;
900 FT_Pos offset;
901 FT_Pos threshold = 64;
902
903
904 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
905 {
906 if ( ( edge->flags & AF_EDGE_ROUND ) &&
907 ( edge2->flags & AF_EDGE_ROUND ) )
908 {
909 if ( dim == AF_DIMENSION_VERT )
910 threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP;
911 else
912 threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP;
913 }
914 else
915 {
916 if ( dim == AF_DIMENSION_VERT )
917 threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3;
918 else
919 threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3;
920 }
921 }
922
923 org_len = edge2->opos - edge->opos;
924 cur_len = af_cjk_compute_stem_width( hints, dim, org_len,
925 (AF_Edge_Flags)edge->flags,
926 (AF_Edge_Flags)edge2->flags );
927
928 org_center = ( edge->opos + edge2->opos ) / 2 + anchor;
929 cur_pos1 = org_center - cur_len / 2;
930 cur_pos2 = cur_pos1 + cur_len;
931 d_off1 = cur_pos1 - FT_PIX_FLOOR( cur_pos1 );
932 d_off2 = cur_pos2 - FT_PIX_FLOOR( cur_pos2 );
933 u_off1 = 64 - d_off1;
934 u_off2 = 64 - d_off2;
935 delta = 0;
936
937
938 if ( d_off1 == 0 || d_off2 == 0 )
939 goto Exit;
940
941 if ( cur_len <= threshold )
942 {
943 if ( d_off2 < cur_len )
944 {
945 if ( u_off1 <= d_off2 )
946 delta = u_off1;
947 else
948 delta = -d_off2;
949 }
950
951 goto Exit;
952 }
953
954 if ( threshold < 64 )
955 {
956 if ( d_off1 >= threshold || u_off1 >= threshold ||
957 d_off2 >= threshold || u_off2 >= threshold )
958 goto Exit;
959 }
960
961 offset = cur_len % 64;
962
963 if ( offset < 32 )
964 {
965 if ( u_off1 <= offset || d_off2 <= offset )
966 goto Exit;
967 }
968 else
969 offset = 64 - threshold;
970
971 d_off1 = threshold - u_off1;
972 u_off1 = u_off1 - offset;
973 u_off2 = threshold - d_off2;
974 d_off2 = d_off2 - offset;
975
976 if ( d_off1 <= u_off1 )
977 u_off1 = -d_off1;
978
979 if ( d_off2 <= u_off2 )
980 u_off2 = -d_off2;
981
982 if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) )
983 delta = u_off1;
984 else
985 delta = u_off2;
986
987 Exit:
988
989 #if 1
990 if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
991 {
992 if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS )
993 delta = AF_LIGHT_MODE_MAX_DELTA_ABS;
994 else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS )
995 delta = -AF_LIGHT_MODE_MAX_DELTA_ABS;
996 }
997 #endif
998
999 cur_pos1 += delta;
1000
1001 if ( edge->opos < edge2->opos )
1002 {
1003 edge->pos = cur_pos1;
1004 edge2->pos = cur_pos1 + cur_len;
1005 }
1006 else
1007 {
1008 edge->pos = cur_pos1 + cur_len;
1009 edge2->pos = cur_pos1;
1010 }
1011
1012 return delta;
1013 }
1014
1015
1016 static void
1017 af_cjk_hint_edges( AF_GlyphHints hints,
1018 AF_Dimension dim )
1019 {
1020 AF_AxisHints axis = &hints->axis[dim];
1021 AF_Edge edges = axis->edges;
1022 AF_Edge edge_limit = edges + axis->num_edges;
1023 FT_PtrDist n_edges;
1024 AF_Edge edge;
1025 AF_Edge anchor = 0;
1026 FT_Pos delta = 0;
1027 FT_Int skipped = 0;
1028
1029
1030 /* now we align all stem edges. */
1031 for ( edge = edges; edge < edge_limit; edge++ )
1032 {
1033 AF_Edge edge2;
1034
1035
1036 if ( edge->flags & AF_EDGE_DONE )
1037 continue;
1038
1039 /* skip all non-stem edges */
1040 edge2 = edge->link;
1041 if ( !edge2 )
1042 {
1043 skipped++;
1044 continue;
1045 }
1046
1047 /* now align the stem */
1048
1049 if ( edge2 < edge )
1050 {
1051 af_cjk_align_linked_edge( hints, dim, edge2, edge );
1052 edge->flags |= AF_EDGE_DONE;
1053 continue;
1054 }
1055
1056 if ( dim != AF_DIMENSION_VERT && !anchor )
1057 {
1058
1059 #if 0
1060 if ( fixedpitch )
1061 {
1062 AF_Edge left = edge;
1063 AF_Edge right = edge_limit - 1;
1064 AF_EdgeRec left1, left2, right1, right2;
1065 FT_Pos target, center1, center2;
1066 FT_Pos delta1, delta2, d1, d2;
1067
1068
1069 while ( right > left && !right->link )
1070 right--;
1071
1072 left1 = *left;
1073 left2 = *left->link;
1074 right1 = *right->link;
1075 right2 = *right;
1076
1077 delta = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2;
1078 target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16;
1079
1080 delta1 = delta;
1081 delta1 += af_hint_normal_stem( hints, left, left->link,
1082 delta1, 0 );
1083
1084 if ( left->link != right )
1085 af_hint_normal_stem( hints, right->link, right, delta1, 0 );
1086
1087 center1 = left->pos + ( right->pos - left->pos ) / 2;
1088
1089 if ( center1 >= target )
1090 delta2 = delta - 32;
1091 else
1092 delta2 = delta + 32;
1093
1094 delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 );
1095
1096 if ( delta1 != delta2 )
1097 {
1098 if ( left->link != right )
1099 af_hint_normal_stem( hints, &right1, &right2, delta2, 0 );
1100
1101 center2 = left1.pos + ( right2.pos - left1.pos ) / 2;
1102
1103 d1 = center1 - target;
1104 d2 = center2 - target;
1105
1106 if ( FT_ABS( d2 ) < FT_ABS( d1 ) )
1107 {
1108 left->pos = left1.pos;
1109 left->link->pos = left2.pos;
1110
1111 if ( left->link != right )
1112 {
1113 right->link->pos = right1.pos;
1114 right->pos = right2.pos;
1115 }
1116
1117 delta1 = delta2;
1118 }
1119 }
1120
1121 delta = delta1;
1122 right->link->flags |= AF_EDGE_DONE;
1123 right->flags |= AF_EDGE_DONE;
1124 }
1125 else
1126
1127 #endif /* 0 */
1128
1129 delta = af_hint_normal_stem( hints, edge, edge2, 0,
1130 AF_DIMENSION_HORZ );
1131 }
1132 else
1133 af_hint_normal_stem( hints, edge, edge2, delta, dim );
1134
1135 #if 0
1136 printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n",
1137 edge - edges, edge2 - edges,
1138 ( edge->pos - edge->opos ) / 64.0,
1139 ( edge2->pos - edge2->opos ) / 64.0 );
1140 #endif
1141
1142 anchor = edge;
1143 edge->flags |= AF_EDGE_DONE;
1144 edge2->flags |= AF_EDGE_DONE;
1145 }
1146
1147 /* make sure that lowercase m's maintain their symmetry */
1148
1149 /* In general, lowercase m's have six vertical edges if they are sans */
1150 /* serif, or twelve if they are with serifs. This implementation is */
1151 /* based on that assumption, and seems to work very well with most */
1152 /* faces. However, if for a certain face this assumption is not */
1153 /* true, the m is just rendered like before. In addition, any stem */
1154 /* correction will only be applied to symmetrical glyphs (even if the */
1155 /* glyph is not an m), so the potential for unwanted distortion is */
1156 /* relatively low. */
1157
1158 /* We don't handle horizontal edges since we can't easily assure that */
1159 /* the third (lowest) stem aligns with the base line; it might end up */
1160 /* one pixel higher or lower. */
1161
1162 n_edges = edge_limit - edges;
1163 if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 || n_edges == 12 ) )
1164 {
1165 AF_Edge edge1, edge2, edge3;
1166 FT_Pos dist1, dist2, span;
1167
1168
1169 if ( n_edges == 6 )
1170 {
1171 edge1 = edges;
1172 edge2 = edges + 2;
1173 edge3 = edges + 4;
1174 }
1175 else
1176 {
1177 edge1 = edges + 1;
1178 edge2 = edges + 5;
1179 edge3 = edges + 9;
1180 }
1181
1182 dist1 = edge2->opos - edge1->opos;
1183 dist2 = edge3->opos - edge2->opos;
1184
1185 span = dist1 - dist2;
1186 if ( span < 0 )
1187 span = -span;
1188
1189 if ( edge1->link == edge1 + 1 &&
1190 edge2->link == edge2 + 1 &&
1191 edge3->link == edge3 + 1 && span < 8 )
1192 {
1193 delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
1194 edge3->pos -= delta;
1195 if ( edge3->link )
1196 edge3->link->pos -= delta;
1197
1198 /* move the serifs along with the stem */
1199 if ( n_edges == 12 )
1200 {
1201 ( edges + 8 )->pos -= delta;
1202 ( edges + 11 )->pos -= delta;
1203 }
1204
1205 edge3->flags |= AF_EDGE_DONE;
1206 if ( edge3->link )
1207 edge3->link->flags |= AF_EDGE_DONE;
1208 }
1209 }
1210
1211 if ( !skipped )
1212 return;
1213
1214 /*
1215 * now hint the remaining edges (serifs and single) in order
1216 * to complete our processing
1217 */
1218 for ( edge = edges; edge < edge_limit; edge++ )
1219 {
1220 if ( edge->flags & AF_EDGE_DONE )
1221 continue;
1222
1223 if ( edge->serif )
1224 {
1225 af_cjk_align_serif_edge( hints, edge->serif, edge );
1226 edge->flags |= AF_EDGE_DONE;
1227 skipped--;
1228 }
1229 }
1230
1231 if ( !skipped )
1232 return;
1233
1234 for ( edge = edges; edge < edge_limit; edge++ )
1235 {
1236 AF_Edge before, after;
1237
1238
1239 if ( edge->flags & AF_EDGE_DONE )
1240 continue;
1241
1242 before = after = edge;
1243
1244 while ( --before >= edges )
1245 if ( before->flags & AF_EDGE_DONE )
1246 break;
1247
1248 while ( ++after < edge_limit )
1249 if ( after->flags & AF_EDGE_DONE )
1250 break;
1251
1252 if ( before >= edges || after < edge_limit )
1253 {
1254 if ( before < edges )
1255 af_cjk_align_serif_edge( hints, after, edge );
1256 else if ( after >= edge_limit )
1257 af_cjk_align_serif_edge( hints, before, edge );
1258 else
1259 {
1260 if ( after->fpos == before->fpos )
1261 edge->pos = before->pos;
1262 else
1263 edge->pos = before->pos +
1264 FT_MulDiv( edge->fpos - before->fpos,
1265 after->pos - before->pos,
1266 after->fpos - before->fpos );
1267 }
1268 }
1269 }
1270 }
1271
1272
1273 static void
1274 af_cjk_align_edge_points( AF_GlyphHints hints,
1275 AF_Dimension dim )
1276 {
1277 AF_AxisHints axis = & hints->axis[dim];
1278 AF_Edge edges = axis->edges;
1279 AF_Edge edge_limit = edges + axis->num_edges;
1280 AF_Edge edge;
1281 FT_Bool snapping;
1282
1283
1284 snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ &&
1285 AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) ||
1286 ( dim == AF_DIMENSION_VERT &&
1287 AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) );
1288
1289 for ( edge = edges; edge < edge_limit; edge++ )
1290 {
1291 /* move the points of each segment */
1292 /* in each edge to the edge's position */
1293 AF_Segment seg = edge->first;
1294
1295
1296 if ( snapping )
1297 {
1298 do
1299 {
1300 AF_Point point = seg->first;
1301
1302
1303 for (;;)
1304 {
1305 if ( dim == AF_DIMENSION_HORZ )
1306 {
1307 point->x = edge->pos;
1308 point->flags |= AF_FLAG_TOUCH_X;
1309 }
1310 else
1311 {
1312 point->y = edge->pos;
1313 point->flags |= AF_FLAG_TOUCH_Y;
1314 }
1315
1316 if ( point == seg->last )
1317 break;
1318
1319 point = point->next;
1320 }
1321
1322 seg = seg->edge_next;
1323
1324 } while ( seg != edge->first );
1325 }
1326 else
1327 {
1328 FT_Pos delta = edge->pos - edge->opos;
1329
1330
1331 do
1332 {
1333 AF_Point point = seg->first;
1334
1335
1336 for (;;)
1337 {
1338 if ( dim == AF_DIMENSION_HORZ )
1339 {
1340 point->x += delta;
1341 point->flags |= AF_FLAG_TOUCH_X;
1342 }
1343 else
1344 {
1345 point->y += delta;
1346 point->flags |= AF_FLAG_TOUCH_Y;
1347 }
1348
1349 if ( point == seg->last )
1350 break;
1351
1352 point = point->next;
1353 }
1354
1355 seg = seg->edge_next;
1356
1357 } while ( seg != edge->first );
1358 }
1359 }
1360 }
1361
1362
1363 FT_LOCAL_DEF( FT_Error )
1364 af_cjk_hints_apply( AF_GlyphHints hints,
1365 FT_Outline* outline,
1366 AF_LatinMetrics metrics )
1367 {
1368 FT_Error error;
1369 int dim;
1370
1371 FT_UNUSED( metrics );
1372
1373
1374 error = af_glyph_hints_reload( hints, outline, 0 );
1375 if ( error )
1376 goto Exit;
1377
1378 /* analyze glyph outline */
1379 if ( AF_HINTS_DO_HORIZONTAL( hints ) )
1380 {
1381 error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ );
1382 if ( error )
1383 goto Exit;
1384 }
1385
1386 if ( AF_HINTS_DO_VERTICAL( hints ) )
1387 {
1388 error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
1389 if ( error )
1390 goto Exit;
1391 }
1392
1393 /* grid-fit the outline */
1394 for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
1395 {
1396 if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) ||
1397 ( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) )
1398 {
1399
1400 #ifdef AF_USE_WARPER
1401 if ( dim == AF_DIMENSION_HORZ &&
1402 metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL )
1403 {
1404 AF_WarperRec warper;
1405 FT_Fixed scale;
1406 FT_Pos delta;
1407
1408
1409 af_warper_compute( &warper, hints, dim, &scale, &delta );
1410 af_glyph_hints_scale_dim( hints, dim, scale, delta );
1411 continue;
1412 }
1413 #endif /* AF_USE_WARPER */
1414
1415 af_cjk_hint_edges( hints, (AF_Dimension)dim );
1416 af_cjk_align_edge_points( hints, (AF_Dimension)dim );
1417 af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
1418 af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
1419 }
1420 }
1421
1422 #if 0
1423 af_glyph_hints_dump_points( hints );
1424 af_glyph_hints_dump_segments( hints );
1425 af_glyph_hints_dump_edges( hints );
1426 #endif
1427
1428 af_glyph_hints_save( hints, outline );
1429
1430 Exit:
1431 return error;
1432 }
1433
1434
1435 /*************************************************************************/
1436 /*************************************************************************/
1437 /***** *****/
1438 /***** C J K S C R I P T C L A S S *****/
1439 /***** *****/
1440 /*************************************************************************/
1441 /*************************************************************************/
1442
1443
1444 static const AF_Script_UniRangeRec af_cjk_uniranges[] =
1445 {
1446 #if 0
1447 AF_UNIRANGE_REC( 0x0100UL, 0xFFFFUL ), /* why this? */
1448 #endif
1449 AF_UNIRANGE_REC( 0x2E80UL, 0x2EFFUL ), /* CJK Radicals Supplement */
1450 AF_UNIRANGE_REC( 0x2F00UL, 0x2FDFUL ), /* Kangxi Radicals */
1451 AF_UNIRANGE_REC( 0x3000UL, 0x303FUL ), /* CJK Symbols and Punctuation */
1452 AF_UNIRANGE_REC( 0x3040UL, 0x309FUL ), /* Hiragana */
1453 AF_UNIRANGE_REC( 0x30A0UL, 0x30FFUL ), /* Katakana */
1454 AF_UNIRANGE_REC( 0x3100UL, 0x312FUL ), /* Bopomofo */
1455 AF_UNIRANGE_REC( 0x3130UL, 0x318FUL ), /* Hangul Compatibility Jamo */
1456 AF_UNIRANGE_REC( 0x31A0UL, 0x31BFUL ), /* Bopomofo Extended */
1457 AF_UNIRANGE_REC( 0x31C0UL, 0x31EFUL ), /* CJK Strokes */
1458 AF_UNIRANGE_REC( 0x31F0UL, 0x31FFUL ), /* Katakana Phonetic Extensions */
1459 AF_UNIRANGE_REC( 0x3200UL, 0x32FFUL ), /* Enclosed CJK Letters and Months */
1460 AF_UNIRANGE_REC( 0x3300UL, 0x33FFUL ), /* CJK Compatibility */
1461 AF_UNIRANGE_REC( 0x3400UL, 0x4DBFUL ), /* CJK Unified Ideographs Extension A */
1462 AF_UNIRANGE_REC( 0x4DC0UL, 0x4DFFUL ), /* Yijing Hexagram Symbols */
1463 AF_UNIRANGE_REC( 0x4E00UL, 0x9FFFUL ), /* CJK Unified Ideographs */
1464 AF_UNIRANGE_REC( 0xF900UL, 0xFAFFUL ), /* CJK Compatibility Ideographs */
1465 AF_UNIRANGE_REC( 0xFE30UL, 0xFE4FUL ), /* CJK Compatibility Forms */
1466 AF_UNIRANGE_REC( 0xFF00UL, 0xFFEFUL ), /* Halfwidth and Fullwidth Forms */
1467 AF_UNIRANGE_REC( 0x20000UL, 0x2A6DFUL ), /* CJK Unified Ideographs Extension B */
1468 AF_UNIRANGE_REC( 0x2F800UL, 0x2FA1FUL ), /* CJK Compatibility Ideographs Supplement */
1469 AF_UNIRANGE_REC( 0UL, 0UL )
1470 };
1471
1472
1473 AF_DEFINE_SCRIPT_CLASS(af_cjk_script_class,
1474 AF_SCRIPT_CJK,
1475 af_cjk_uniranges,
1476
1477 sizeof( AF_LatinMetricsRec ),
1478
1479 (AF_Script_InitMetricsFunc) af_cjk_metrics_init,
1480 (AF_Script_ScaleMetricsFunc)af_cjk_metrics_scale,
1481 (AF_Script_DoneMetricsFunc) NULL,
1482
1483 (AF_Script_InitHintsFunc) af_cjk_hints_init,
1484 (AF_Script_ApplyHintsFunc) af_cjk_hints_apply
1485 )
1486
1487 #else /* !AF_CONFIG_OPTION_CJK */
1488
1489 static const AF_Script_UniRangeRec af_cjk_uniranges[] =
1490 {
1491 AF_UNIRANGE_REC( 0UL, 0UL )
1492 };
1493
1494
1495 AF_DEFINE_SCRIPT_CLASS(af_cjk_script_class,
1496 AF_SCRIPT_CJK,
1497 af_cjk_uniranges,
1498
1499 sizeof( AF_LatinMetricsRec ),
1500
1501 (AF_Script_InitMetricsFunc) NULL,
1502 (AF_Script_ScaleMetricsFunc)NULL,
1503 (AF_Script_DoneMetricsFunc) NULL,
1504
1505 (AF_Script_InitHintsFunc) NULL,
1506 (AF_Script_ApplyHintsFunc) NULL
1507 )
1508
1509 #endif /* !AF_CONFIG_OPTION_CJK */
1510
1511
1512 /* END */
A free Windows-compatible Operating System