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source: trunk/poppler/freetype2/src/autofit/afcjk.c @ 262

Last change on this file since 262 was 262, checked in by Eugene Romanenko, 12 years ago
PDF plugin: freetype library updated to version 2.3.8
File size: 43.7 KB

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1	/***************************************************************************/
2	/* */
3	/* afcjk.c */
4	/* */
5	/* Auto-fitter hinting routines for CJK script (body). */
6	/* */
7	/* Copyright 2006, 2007, 2008 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
62	/* latin's version would suffice */
63	af_latin_metrics_init_widths( metrics, face, 0x7530 );
64
65	FT_Set_Charmap( face, oldmap );
66
67	return AF_Err_Ok;
68	}
69
70
71	static void
72	af_cjk_metrics_scale_dim( AF_LatinMetrics metrics,
73	AF_Scaler scaler,
74	AF_Dimension dim )
75	{
76	AF_LatinAxis axis;
77
78
79	axis = &metrics->axis[dim];
80
81	if ( dim == AF_DIMENSION_HORZ )
82	{
83	axis->scale = scaler->x_scale;
84	axis->delta = scaler->x_delta;
85	}
86	else
87	{
88	axis->scale = scaler->y_scale;
89	axis->delta = scaler->y_delta;
90	}
91	}
92
93
94	FT_LOCAL_DEF( void )
95	af_cjk_metrics_scale( AF_LatinMetrics metrics,
96	AF_Scaler scaler )
97	{
98	metrics->root.scaler = *scaler;
99
100	af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
101	af_cjk_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
102	}
103
104
105	/*************************************************************************/
106	/*************************************************************************/
107	/*** ***/
108	/*** C J K G L Y P H A N A L Y S I S ***/
109	/*** ***/
110	/*************************************************************************/
111	/*************************************************************************/
112
113	static FT_Error
114	af_cjk_hints_compute_segments( AF_GlyphHints hints,
115	AF_Dimension dim )
116	{
117	AF_AxisHints axis = &hints->axis[dim];
118	AF_Segment segments = axis->segments;
119	AF_Segment segment_limit = segments + axis->num_segments;
120	FT_Error error;
121	AF_Segment seg;
122
123
124	error = af_latin_hints_compute_segments( hints, dim );
125	if ( error )
126	return error;
127
128	/* a segment is round if it doesn't have successive */
129	/* on-curve points. */
130	for ( seg = segments; seg < segment_limit; seg++ )
131	{
132	AF_Point pt = seg->first;
133	AF_Point last = seg->last;
134	AF_Flags f0 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL);
135	AF_Flags f1;
136
137
138	seg->flags &= ~AF_EDGE_ROUND;
139
140	for ( ; pt != last; f0 = f1 )
141	{
142	pt = pt->next;
143	f1 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL);
144
145	if ( !f0 && !f1 )
146	break;
147
148	if ( pt == last )
149	seg->flags \|= AF_EDGE_ROUND;
150	}
151	}
152
153	return AF_Err_Ok;
154	}
155
156
157	static void
158	af_cjk_hints_link_segments( AF_GlyphHints hints,
159	AF_Dimension dim )
160	{
161	AF_AxisHints axis = &hints->axis[dim];
162	AF_Segment segments = axis->segments;
163	AF_Segment segment_limit = segments + axis->num_segments;
164	AF_Direction major_dir = axis->major_dir;
165	AF_Segment seg1, seg2;
166	FT_Pos len_threshold;
167	FT_Pos dist_threshold;
168
169
170	len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
171
172	dist_threshold = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
173	: hints->y_scale;
174	dist_threshold = FT_DivFix( 64 * 3, dist_threshold );
175
176	/* now compare each segment to the others */
177	for ( seg1 = segments; seg1 < segment_limit; seg1++ )
178	{
179	/* the fake segments are for metrics hinting only */
180	if ( seg1->first == seg1->last )
181	continue;
182
183	if ( seg1->dir != major_dir )
184	continue;
185
186	for ( seg2 = segments; seg2 < segment_limit; seg2++ )
187	if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
188	{
189	FT_Pos dist = seg2->pos - seg1->pos;
190
191
192	if ( dist < 0 )
193	continue;
194
195	{
196	FT_Pos min = seg1->min_coord;
197	FT_Pos max = seg1->max_coord;
198	FT_Pos len;
199
200
201	if ( min < seg2->min_coord )
202	min = seg2->min_coord;
203
204	if ( max > seg2->max_coord )
205	max = seg2->max_coord;
206
207	len = max - min;
208	if ( len >= len_threshold )
209	{
210	if ( dist * 8 < seg1->score * 9 &&
211	( dist * 8 < seg1->score * 7 \|\| seg1->len < len ) )
212	{
213	seg1->score = dist;
214	seg1->len = len;
215	seg1->link = seg2;
216	}
217
218	if ( dist * 8 < seg2->score * 9 &&
219	( dist * 8 < seg2->score * 7 \|\| seg2->len < len ) )
220	{
221	seg2->score = dist;
222	seg2->len = len;
223	seg2->link = seg1;
224	}
225	}
226	}
227	}
228	}
229
230	/*
231	* now compute the `serif' segments
232	*
233	* In Hanzi, some strokes are wider on one or both of the ends.
234	* We either identify the stems on the ends as serifs or remove
235	* the linkage, depending on the length of the stems.
236	*
237	*/
238
239	{
240	AF_Segment link1, link2;
241
242
243	for ( seg1 = segments; seg1 < segment_limit; seg1++ )
244	{
245	link1 = seg1->link;
246	if ( !link1 \|\| link1->link != seg1 \|\| link1->pos <= seg1->pos )
247	continue;
248
249	if ( seg1->score >= dist_threshold )
250	continue;
251
252	for ( seg2 = segments; seg2 < segment_limit; seg2++ )
253	{
254	if ( seg2->pos > seg1->pos \|\| seg1 == seg2 )
255	continue;
256
257	link2 = seg2->link;
258	if ( !link2 \|\| link2->link != seg2 \|\| link2->pos < link1->pos )
259	continue;
260
261	if ( seg1->pos == seg2->pos && link1->pos == link2->pos )
262	continue;
263
264	if ( seg2->score <= seg1->score \|\| seg1->score * 4 <= seg2->score )
265	continue;
266
267	/* seg2 < seg1 < link1 < link2 */
268
269	if ( seg1->len >= seg2->len * 3 )
270	{
271	AF_Segment seg;
272
273
274	for ( seg = segments; seg < segment_limit; seg++ )
275	{
276	AF_Segment link = seg->link;
277
278
279	if ( link == seg2 )
280	{
281	seg->link = 0;
282	seg->serif = link1;
283	}
284	else if ( link == link2 )
285	{
286	seg->link = 0;
287	seg->serif = seg1;
288	}
289	}
290	}
291	else
292	{
293	seg1->link = link1->link = 0;
294
295	break;
296	}
297	}
298	}
299	}
300
301	for ( seg1 = segments; seg1 < segment_limit; seg1++ )
302	{
303	seg2 = seg1->link;
304
305	if ( seg2 )
306	{
307	seg2->num_linked++;
308	if ( seg2->link != seg1 )
309	{
310	seg1->link = 0;
311
312	if ( seg2->score < dist_threshold \|\| seg1->score < seg2->score * 4 )
313	seg1->serif = seg2->link;
314	else
315	seg2->num_linked--;
316	}
317	}
318	}
319	}
320
321
322	static FT_Error
323	af_cjk_hints_compute_edges( AF_GlyphHints hints,
324	AF_Dimension dim )
325	{
326	AF_AxisHints axis = &hints->axis[dim];
327	FT_Error error = AF_Err_Ok;
328	FT_Memory memory = hints->memory;
329	AF_LatinAxis laxis = &((AF_LatinMetrics)hints->metrics)->axis[dim];
330
331	AF_Segment segments = axis->segments;
332	AF_Segment segment_limit = segments + axis->num_segments;
333	AF_Segment seg;
334
335	FT_Fixed scale;
336	FT_Pos edge_distance_threshold;
337
338
339	axis->num_edges = 0;
340
341	scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
342	: hints->y_scale;
343
344	/*********************************************************************/
345	/* */
346	/* We begin by generating a sorted table of edges for the current */
347	/* direction. To do so, we simply scan each segment and try to find */
348	/* an edge in our table that corresponds to its position. */
349	/* */
350	/* If no edge is found, we create and insert a new edge in the */
351	/* sorted table. Otherwise, we simply add the segment to the edge's */
352	/* list which is then processed in the second step to compute the */
353	/* edge's properties. */
354	/* */
355	/* Note that the edges table is sorted along the segment/edge */
356	/* position. */
357	/* */
358	/*********************************************************************/
359
360	edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
361	scale );
362	if ( edge_distance_threshold > 64 / 4 )
363	edge_distance_threshold = FT_DivFix( 64 / 4, scale );
364	else
365	edge_distance_threshold = laxis->edge_distance_threshold;
366
367	for ( seg = segments; seg < segment_limit; seg++ )
368	{
369	AF_Edge found = 0;
370	FT_Pos best = 0xFFFFU;
371	FT_Int ee;
372
373
374	/* look for an edge corresponding to the segment */
375	for ( ee = 0; ee < axis->num_edges; ee++ )
376	{
377	AF_Edge edge = axis->edges + ee;
378	FT_Pos dist;
379
380
381	if ( edge->dir != seg->dir )
382	continue;
383
384	dist = seg->pos - edge->fpos;
385	if ( dist < 0 )
386	dist = -dist;
387
388	if ( dist < edge_distance_threshold && dist < best )
389	{
390	AF_Segment link = seg->link;
391
392
393	/* check whether all linked segments of the candidate edge */
394	/* can make a single edge. */
395	if ( link )
396	{
397	AF_Segment seg1 = edge->first;
398	AF_Segment link1;
399	FT_Pos dist2 = 0;
400
401
402	do
403	{
404	link1 = seg1->link;
405	if ( link1 )
406	{
407	dist2 = AF_SEGMENT_DIST( link, link1 );
408	if ( dist2 >= edge_distance_threshold )
409	break;
410	}
411
412	} while ( ( seg1 = seg1->edge_next ) != edge->first );
413
414	if ( dist2 >= edge_distance_threshold )
415	continue;
416	}
417
418	best = dist;
419	found = edge;
420	}
421	}
422
423	if ( !found )
424	{
425	AF_Edge edge;
426
427
428	/* insert a new edge in the list and */
429	/* sort according to the position */
430	error = af_axis_hints_new_edge( axis, seg->pos,
431	(AF_Direction)seg->dir,
432	memory, &edge );
433	if ( error )
434	goto Exit;
435
436	/* add the segment to the new edge's list */
437	FT_ZERO( edge );
438
439	edge->first = seg;
440	edge->last = seg;
441	edge->fpos = seg->pos;
442	edge->opos = edge->pos = FT_MulFix( seg->pos, scale );
443	seg->edge_next = seg;
444	edge->dir = seg->dir;
445	}
446	else
447	{
448	/* if an edge was found, simply add the segment to the edge's */
449	/* list */
450	seg->edge_next = found->first;
451	found->last->edge_next = seg;
452	found->last = seg;
453	}
454	}
455
456	/*********************************************************************/
457	/* */
458	/* Good, we now compute each edge's properties according to segments */
459	/* found on its position. Basically, these are as follows. */
460	/* */
461	/* - edge's main direction */
462	/* - stem edge, serif edge or both (which defaults to stem then) */
463	/* - rounded edge, straight or both (which defaults to straight) */
464	/* - link for edge */
465	/* */
466	/*********************************************************************/
467
468	/* first of all, set the `edge' field in each segment -- this is */
469	/* required in order to compute edge links */
470	/* */
471	/* Note that removing this loop and setting the `edge' field of each */
472	/* segment directly in the code above slows down execution speed for */
473	/* some reasons on platforms like the Sun. */
474
475	{
476	AF_Edge edges = axis->edges;
477	AF_Edge edge_limit = edges + axis->num_edges;
478	AF_Edge edge;
479
480
481	for ( edge = edges; edge < edge_limit; edge++ )
482	{
483	seg = edge->first;
484	if ( seg )
485	do
486	{
487	seg->edge = edge;
488	seg = seg->edge_next;
489
490	} while ( seg != edge->first );
491	}
492
493	/* now compute each edge properties */
494	for ( edge = edges; edge < edge_limit; edge++ )
495	{
496	FT_Int is_round = 0; /* does it contain round segments? */
497	FT_Int is_straight = 0; /* does it contain straight segments? */
498
499
500	seg = edge->first;
501
502	do
503	{
504	FT_Bool is_serif;
505
506
507	/* check for roundness of segment */
508	if ( seg->flags & AF_EDGE_ROUND )
509	is_round++;
510	else
511	is_straight++;
512
513	/* check for links -- if seg->serif is set, then seg->link must */
514	/* be ignored */
515	is_serif = (FT_Bool)( seg->serif && seg->serif->edge != edge );
516
517	if ( seg->link \|\| is_serif )
518	{
519	AF_Edge edge2;
520	AF_Segment seg2;
521
522
523	edge2 = edge->link;
524	seg2 = seg->link;
525
526	if ( is_serif )
527	{
528	seg2 = seg->serif;
529	edge2 = edge->serif;
530	}
531
532	if ( edge2 )
533	{
534	FT_Pos edge_delta;
535	FT_Pos seg_delta;
536
537
538	edge_delta = edge->fpos - edge2->fpos;
539	if ( edge_delta < 0 )
540	edge_delta = -edge_delta;
541
542	seg_delta = AF_SEGMENT_DIST( seg, seg2 );
543
544	if ( seg_delta < edge_delta )
545	edge2 = seg2->edge;
546	}
547	else
548	edge2 = seg2->edge;
549
550	if ( is_serif )
551	{
552	edge->serif = edge2;
553	edge2->flags \|= AF_EDGE_SERIF;
554	}
555	else
556	edge->link = edge2;
557	}
558
559	seg = seg->edge_next;
560
561	} while ( seg != edge->first );
562
563	/* set the round/straight flags */
564	edge->flags = AF_EDGE_NORMAL;
565
566	if ( is_round > 0 && is_round >= is_straight )
567	edge->flags \|= AF_EDGE_ROUND;
568
569	/* get rid of serifs if link is set */
570	/* XXX: This gets rid of many unpleasant artefacts! */
571	/* Example: the `c' in cour.pfa at size 13 */
572
573	if ( edge->serif && edge->link )
574	edge->serif = 0;
575	}
576	}
577
578	Exit:
579	return error;
580	}
581
582
583	static FT_Error
584	af_cjk_hints_detect_features( AF_GlyphHints hints,
585	AF_Dimension dim )
586	{
587	FT_Error error;
588
589
590	error = af_cjk_hints_compute_segments( hints, dim );
591	if ( !error )
592	{
593	af_cjk_hints_link_segments( hints, dim );
594
595	error = af_cjk_hints_compute_edges( hints, dim );
596	}
597	return error;
598	}
599
600
601	FT_LOCAL_DEF( FT_Error )
602	af_cjk_hints_init( AF_GlyphHints hints,
603	AF_LatinMetrics metrics )
604	{
605	FT_Render_Mode mode;
606	FT_UInt32 scaler_flags, other_flags;
607
608
609	af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics );
610
611	/*
612	* correct x_scale and y_scale when needed, since they may have
613	* been modified af_cjk_scale_dim above
614	*/
615	hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
616	hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
617	hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
618	hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
619
620	/* compute flags depending on render mode, etc. */
621	mode = metrics->root.scaler.render_mode;
622
623	#ifdef AF_USE_WARPER
624	if ( mode == FT_RENDER_MODE_LCD \|\| mode == FT_RENDER_MODE_LCD_V )
625	metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
626	#endif
627
628	scaler_flags = hints->scaler_flags;
629	other_flags = 0;
630
631	/*
632	* We snap the width of vertical stems for the monochrome and
633	* horizontal LCD rendering targets only.
634	*/
635	if ( mode == FT_RENDER_MODE_MONO \|\| mode == FT_RENDER_MODE_LCD )
636	other_flags \|= AF_LATIN_HINTS_HORZ_SNAP;
637
638	/*
639	* We snap the width of horizontal stems for the monochrome and
640	* vertical LCD rendering targets only.
641	*/
642	if ( mode == FT_RENDER_MODE_MONO \|\| mode == FT_RENDER_MODE_LCD_V )
643	other_flags \|= AF_LATIN_HINTS_VERT_SNAP;
644
645	/*
646	* We adjust stems to full pixels only if we don't use the `light' mode.
647	*/
648	if ( mode != FT_RENDER_MODE_LIGHT )
649	other_flags \|= AF_LATIN_HINTS_STEM_ADJUST;
650
651	if ( mode == FT_RENDER_MODE_MONO )
652	other_flags \|= AF_LATIN_HINTS_MONO;
653
654	scaler_flags \|= AF_SCALER_FLAG_NO_ADVANCE;
655
656	hints->scaler_flags = scaler_flags;
657	hints->other_flags = other_flags;
658
659	return 0;
660	}
661
662
663	/*************************************************************************/
664	/*************************************************************************/
665	/*** ***/
666	/*** C J K G L Y P H G R I D - F I T T I N G ***/
667	/*** ***/
668	/*************************************************************************/
669	/*************************************************************************/
670
671	/* snap a given width in scaled coordinates to one of the */
672	/* current standard widths */
673
674	static FT_Pos
675	af_cjk_snap_width( AF_Width widths,
676	FT_Int count,
677	FT_Pos width )
678	{
679	int n;
680	FT_Pos best = 64 + 32 + 2;
681	FT_Pos reference = width;
682	FT_Pos scaled;
683
684
685	for ( n = 0; n < count; n++ )
686	{
687	FT_Pos w;
688	FT_Pos dist;
689
690
691	w = widths[n].cur;
692	dist = width - w;
693	if ( dist < 0 )
694	dist = -dist;
695	if ( dist < best )
696	{
697	best = dist;
698	reference = w;
699	}
700	}
701
702	scaled = FT_PIX_ROUND( reference );
703
704	if ( width >= reference )
705	{
706	if ( width < scaled + 48 )
707	width = reference;
708	}
709	else
710	{
711	if ( width > scaled - 48 )
712	width = reference;
713	}
714
715	return width;
716	}
717
718
719	/* compute the snapped width of a given stem */
720
721	static FT_Pos
722	af_cjk_compute_stem_width( AF_GlyphHints hints,
723	AF_Dimension dim,
724	FT_Pos width,
725	AF_Edge_Flags base_flags,
726	AF_Edge_Flags stem_flags )
727	{
728	AF_LatinMetrics metrics = (AF_LatinMetrics) hints->metrics;
729	AF_LatinAxis axis = & metrics->axis[dim];
730	FT_Pos dist = width;
731	FT_Int sign = 0;
732	FT_Int vertical = ( dim == AF_DIMENSION_VERT );
733
734	FT_UNUSED( base_flags );
735	FT_UNUSED( stem_flags );
736
737
738	if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
739	return width;
740
741	if ( dist < 0 )
742	{
743	dist = -width;
744	sign = 1;
745	}
746
747	if ( ( vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) \|\|
748	( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
749	{
750	/* smooth hinting process: very lightly quantize the stem width */
751
752	if ( axis->width_count > 0 )
753	{
754	if ( FT_ABS( dist - axis->widths[0].cur ) < 40 )
755	{
756	dist = axis->widths[0].cur;
757	if ( dist < 48 )
758	dist = 48;
759
760	goto Done_Width;
761	}
762	}
763
764	if ( dist < 54 )
765	dist += ( 54 - dist ) / 2 ;
766	else if ( dist < 3 * 64 )
767	{
768	FT_Pos delta;
769
770
771	delta = dist & 63;
772	dist &= -64;
773
774	if ( delta < 10 )
775	dist += delta;
776	else if ( delta < 22 )
777	dist += 10;
778	else if ( delta < 42 )
779	dist += delta;
780	else if ( delta < 54 )
781	dist += 54;
782	else
783	dist += delta;
784	}
785	}
786	else
787	{
788	/* strong hinting process: snap the stem width to integer pixels */
789
790	dist = af_cjk_snap_width( axis->widths, axis->width_count, dist );
791
792	if ( vertical )
793	{
794	/* in the case of vertical hinting, always round */
795	/* the stem heights to integer pixels */
796
797	if ( dist >= 64 )
798	dist = ( dist + 16 ) & ~63;
799	else
800	dist = 64;
801	}
802	else
803	{
804	if ( AF_LATIN_HINTS_DO_MONO( hints ) )
805	{
806	/* monochrome horizontal hinting: snap widths to integer pixels */
807	/* with a different threshold */
808
809	if ( dist < 64 )
810	dist = 64;
811	else
812	dist = ( dist + 32 ) & ~63;
813	}
814	else
815	{
816	/* for horizontal anti-aliased hinting, we adopt a more subtle */
817	/* approach: we strengthen small stems, round stems whose size */
818	/* is between 1 and 2 pixels to an integer, otherwise nothing */
819
820	if ( dist < 48 )
821	dist = ( dist + 64 ) >> 1;
822
823	else if ( dist < 128 )
824	dist = ( dist + 22 ) & ~63;
825	else
826	/* round otherwise to prevent color fringes in LCD mode */
827	dist = ( dist + 32 ) & ~63;
828	}
829	}
830	}
831
832	Done_Width:
833	if ( sign )
834	dist = -dist;
835
836	return dist;
837	}
838
839
840	/* align one stem edge relative to the previous stem edge */
841
842	static void
843	af_cjk_align_linked_edge( AF_GlyphHints hints,
844	AF_Dimension dim,
845	AF_Edge base_edge,
846	AF_Edge stem_edge )
847	{
848	FT_Pos dist = stem_edge->opos - base_edge->opos;
849
850	FT_Pos fitted_width = af_cjk_compute_stem_width(
851	hints, dim, dist,
852	(AF_Edge_Flags)base_edge->flags,
853	(AF_Edge_Flags)stem_edge->flags );
854
855
856	stem_edge->pos = base_edge->pos + fitted_width;
857	}
858
859
860	static void
861	af_cjk_align_serif_edge( AF_GlyphHints hints,
862	AF_Edge base,
863	AF_Edge serif )
864	{
865	FT_UNUSED( hints );
866
867	serif->pos = base->pos + ( serif->opos - base->opos );
868	}
869
870
871	/*************************************************************************/
872	/*************************************************************************/
873	/*************************************************************************/
874	/** **/
875	/** E D G E H I N T I N G **/
876	/** **/
877	/*************************************************************************/
878	/*************************************************************************/
879	/*************************************************************************/
880
881
882	#define AF_LIGHT_MODE_MAX_HORZ_GAP 9
883	#define AF_LIGHT_MODE_MAX_VERT_GAP 15
884	#define AF_LIGHT_MODE_MAX_DELTA_ABS 14
885
886
887	static FT_Pos
888	af_hint_normal_stem( AF_GlyphHints hints,
889	AF_Edge edge,
890	AF_Edge edge2,
891	FT_Pos anchor,
892	AF_Dimension dim )
893	{
894	FT_Pos org_len, cur_len, org_center;
895	FT_Pos cur_pos1, cur_pos2;
896	FT_Pos d_off1, u_off1, d_off2, u_off2, delta;
897	FT_Pos offset;
898	FT_Pos threshold = 64;
899
900
901	if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
902	{
903	if ( ( edge->flags & AF_EDGE_ROUND ) &&
904	( edge2->flags & AF_EDGE_ROUND ) )
905	{
906	if ( dim == AF_DIMENSION_VERT )
907	threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP;
908	else
909	threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP;
910	}
911	else
912	{
913	if ( dim == AF_DIMENSION_VERT )
914	threshold = 64 - AF_LIGHT_MODE_MAX_HORZ_GAP / 3;
915	else
916	threshold = 64 - AF_LIGHT_MODE_MAX_VERT_GAP / 3;
917	}
918	}
919
920	org_len = edge2->opos - edge->opos;
921	cur_len = af_cjk_compute_stem_width( hints, dim, org_len,
922	(AF_Edge_Flags)edge->flags,
923	(AF_Edge_Flags)edge2->flags );
924
925	org_center = ( edge->opos + edge2->opos ) / 2 + anchor;
926	cur_pos1 = org_center - cur_len / 2;
927	cur_pos2 = cur_pos1 + cur_len;
928	d_off1 = cur_pos1 - FT_PIX_FLOOR( cur_pos1 );
929	d_off2 = cur_pos2 - FT_PIX_FLOOR( cur_pos2 );
930	u_off1 = 64 - d_off1;
931	u_off2 = 64 - d_off2;
932	delta = 0;
933
934
935	if ( d_off1 == 0 \|\| d_off2 == 0 )
936	goto Exit;
937
938	if ( cur_len <= threshold )
939	{
940	if ( d_off2 < cur_len )
941	{
942	if ( u_off1 <= d_off2 )
943	delta = u_off1;
944	else
945	delta = -d_off2;
946	}
947
948	goto Exit;
949	}
950
951	if ( threshold < 64 )
952	{
953	if ( d_off1 >= threshold \|\| u_off1 >= threshold \|\|
954	d_off2 >= threshold \|\| u_off2 >= threshold )
955	goto Exit;
956	}
957
958	offset = cur_len % 64;
959
960	if ( offset < 32 )
961	{
962	if ( u_off1 <= offset \|\| d_off2 <= offset )
963	goto Exit;
964	}
965	else
966	offset = 64 - threshold;
967
968	d_off1 = threshold - u_off1;
969	u_off1 = u_off1 - offset;
970	u_off2 = threshold - d_off2;
971	d_off2 = d_off2 - offset;
972
973	if ( d_off1 <= u_off1 )
974	u_off1 = -d_off1;
975
976	if ( d_off2 <= u_off2 )
977	u_off2 = -d_off2;
978
979	if ( FT_ABS( u_off1 ) <= FT_ABS( u_off2 ) )
980	delta = u_off1;
981	else
982	delta = u_off2;
983
984	Exit:
985
986	#if 1
987	if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) )
988	{
989	if ( delta > AF_LIGHT_MODE_MAX_DELTA_ABS )
990	delta = AF_LIGHT_MODE_MAX_DELTA_ABS;
991	else if ( delta < -AF_LIGHT_MODE_MAX_DELTA_ABS )
992	delta = -AF_LIGHT_MODE_MAX_DELTA_ABS;
993	}
994	#endif
995
996	cur_pos1 += delta;
997
998	if ( edge->opos < edge2->opos )
999	{
1000	edge->pos = cur_pos1;
1001	edge2->pos = cur_pos1 + cur_len;
1002	}
1003	else
1004	{
1005	edge->pos = cur_pos1 + cur_len;
1006	edge2->pos = cur_pos1;
1007	}
1008
1009	return delta;
1010	}
1011
1012
1013	static void
1014	af_cjk_hint_edges( AF_GlyphHints hints,
1015	AF_Dimension dim )
1016	{
1017	AF_AxisHints axis = &hints->axis[dim];
1018	AF_Edge edges = axis->edges;
1019	AF_Edge edge_limit = edges + axis->num_edges;
1020	FT_Int n_edges;
1021	AF_Edge edge;
1022	AF_Edge anchor = 0;
1023	FT_Pos delta = 0;
1024	FT_Int skipped = 0;
1025
1026
1027	/* now we align all stem edges. */
1028	for ( edge = edges; edge < edge_limit; edge++ )
1029	{
1030	AF_Edge edge2;
1031
1032
1033	if ( edge->flags & AF_EDGE_DONE )
1034	continue;
1035
1036	/* skip all non-stem edges */
1037	edge2 = edge->link;
1038	if ( !edge2 )
1039	{
1040	skipped++;
1041	continue;
1042	}
1043
1044	/* now align the stem */
1045
1046	if ( edge2 < edge )
1047	{
1048	af_cjk_align_linked_edge( hints, dim, edge2, edge );
1049	edge->flags \|= AF_EDGE_DONE;
1050	continue;
1051	}
1052
1053	if ( dim != AF_DIMENSION_VERT && !anchor )
1054	{
1055
1056	#if 0
1057	if ( fixedpitch )
1058	{
1059	AF_Edge left = edge;
1060	AF_Edge right = edge_limit - 1;
1061	AF_EdgeRec left1, left2, right1, right2;
1062	FT_Pos target, center1, center2;
1063	FT_Pos delta1, delta2, d1, d2;
1064
1065
1066	while ( right > left && !right->link )
1067	right--;
1068
1069	left1 = *left;
1070	left2 = *left->link;
1071	right1 = *right->link;
1072	right2 = *right;
1073
1074	delta = ( ( ( hinter->pp2.x + 32 ) & -64 ) - hinter->pp2.x ) / 2;
1075	target = left->opos + ( right->opos - left->opos ) / 2 + delta - 16;
1076
1077	delta1 = delta;
1078	delta1 += af_hint_normal_stem( hints, left, left->link,
1079	delta1, 0 );
1080
1081	if ( left->link != right )
1082	af_hint_normal_stem( hints, right->link, right, delta1, 0 );
1083
1084	center1 = left->pos + ( right->pos - left->pos ) / 2;
1085
1086	if ( center1 >= target )
1087	delta2 = delta - 32;
1088	else
1089	delta2 = delta + 32;
1090
1091	delta2 += af_hint_normal_stem( hints, &left1, &left2, delta2, 0 );
1092
1093	if ( delta1 != delta2 )
1094	{
1095	if ( left->link != right )
1096	af_hint_normal_stem( hints, &right1, &right2, delta2, 0 );
1097
1098	center2 = left1.pos + ( right2.pos - left1.pos ) / 2;
1099
1100	d1 = center1 - target;
1101	d2 = center2 - target;
1102
1103	if ( FT_ABS( d2 ) < FT_ABS( d1 ) )
1104	{
1105	left->pos = left1.pos;
1106	left->link->pos = left2.pos;
1107
1108	if ( left->link != right )
1109	{
1110	right->link->pos = right1.pos;
1111	right->pos = right2.pos;
1112	}
1113
1114	delta1 = delta2;
1115	}
1116	}
1117
1118	delta = delta1;
1119	right->link->flags \|= AF_EDGE_DONE;
1120	right->flags \|= AF_EDGE_DONE;
1121	}
1122	else
1123
1124	#endif /* 0 */
1125
1126	delta = af_hint_normal_stem( hints, edge, edge2, 0,
1127	AF_DIMENSION_HORZ );
1128	}
1129	else
1130	af_hint_normal_stem( hints, edge, edge2, delta, dim );
1131
1132	#if 0
1133	printf( "stem (%d,%d) adjusted (%.1f,%.1f)\n",
1134	edge - edges, edge2 - edges,
1135	( edge->pos - edge->opos ) / 64.0,
1136	( edge2->pos - edge2->opos ) / 64.0 );
1137	#endif
1138
1139	anchor = edge;
1140	edge->flags \|= AF_EDGE_DONE;
1141	edge2->flags \|= AF_EDGE_DONE;
1142	}
1143
1144	/* make sure that lowercase m's maintain their symmetry */
1145
1146	/* In general, lowercase m's have six vertical edges if they are sans */
1147	/* serif, or twelve if they are with serifs. This implementation is */
1148	/* based on that assumption, and seems to work very well with most */
1149	/* faces. However, if for a certain face this assumption is not */
1150	/* true, the m is just rendered like before. In addition, any stem */
1151	/* correction will only be applied to symmetrical glyphs (even if the */
1152	/* glyph is not an m), so the potential for unwanted distortion is */
1153	/* relatively low. */
1154
1155	/* We don't handle horizontal edges since we can't easily assure that */
1156	/* the third (lowest) stem aligns with the base line; it might end up */
1157	/* one pixel higher or lower. */
1158
1159	n_edges = edge_limit - edges;
1160	if ( dim == AF_DIMENSION_HORZ && ( n_edges == 6 \|\| n_edges == 12 ) )
1161	{
1162	AF_Edge edge1, edge2, edge3;
1163	FT_Pos dist1, dist2, span;
1164
1165
1166	if ( n_edges == 6 )
1167	{
1168	edge1 = edges;
1169	edge2 = edges + 2;
1170	edge3 = edges + 4;
1171	}
1172	else
1173	{
1174	edge1 = edges + 1;
1175	edge2 = edges + 5;
1176	edge3 = edges + 9;
1177	}
1178
1179	dist1 = edge2->opos - edge1->opos;
1180	dist2 = edge3->opos - edge2->opos;
1181
1182	span = dist1 - dist2;
1183	if ( span < 0 )
1184	span = -span;
1185
1186	if ( edge1->link == edge1 + 1 &&
1187	edge2->link == edge2 + 1 &&
1188	edge3->link == edge3 + 1 && span < 8 )
1189	{
1190	delta = edge3->pos - ( 2 * edge2->pos - edge1->pos );
1191	edge3->pos -= delta;
1192	if ( edge3->link )
1193	edge3->link->pos -= delta;
1194
1195	/* move the serifs along with the stem */
1196	if ( n_edges == 12 )
1197	{
1198	( edges + 8 )->pos -= delta;
1199	( edges + 11 )->pos -= delta;
1200	}
1201
1202	edge3->flags \|= AF_EDGE_DONE;
1203	if ( edge3->link )
1204	edge3->link->flags \|= AF_EDGE_DONE;
1205	}
1206	}
1207
1208	if ( !skipped )
1209	return;
1210
1211	/*
1212	* now hint the remaining edges (serifs and single) in order
1213	* to complete our processing
1214	*/
1215	for ( edge = edges; edge < edge_limit; edge++ )
1216	{
1217	if ( edge->flags & AF_EDGE_DONE )
1218	continue;
1219
1220	if ( edge->serif )
1221	{
1222	af_cjk_align_serif_edge( hints, edge->serif, edge );
1223	edge->flags \|= AF_EDGE_DONE;
1224	skipped--;
1225	}
1226	}
1227
1228	if ( !skipped )
1229	return;
1230
1231	for ( edge = edges; edge < edge_limit; edge++ )
1232	{
1233	AF_Edge before, after;
1234
1235
1236	if ( edge->flags & AF_EDGE_DONE )
1237	continue;
1238
1239	before = after = edge;
1240
1241	while ( --before >= edges )
1242	if ( before->flags & AF_EDGE_DONE )
1243	break;
1244
1245	while ( ++after < edge_limit )
1246	if ( after->flags & AF_EDGE_DONE )
1247	break;
1248
1249	if ( before >= edges \|\| after < edge_limit )
1250	{
1251	if ( before < edges )
1252	af_cjk_align_serif_edge( hints, after, edge );
1253	else if ( after >= edge_limit )
1254	af_cjk_align_serif_edge( hints, before, edge );
1255	else
1256	{
1257	if ( after->fpos == before->fpos )
1258	edge->pos = before->pos;
1259	else
1260	edge->pos = before->pos +
1261	FT_MulDiv( edge->fpos - before->fpos,
1262	after->pos - before->pos,
1263	after->fpos - before->fpos );
1264	}
1265	}
1266	}
1267	}
1268
1269
1270	static void
1271	af_cjk_align_edge_points( AF_GlyphHints hints,
1272	AF_Dimension dim )
1273	{
1274	AF_AxisHints axis = & hints->axis[dim];
1275	AF_Edge edges = axis->edges;
1276	AF_Edge edge_limit = edges + axis->num_edges;
1277	AF_Edge edge;
1278	FT_Bool snapping;
1279
1280
1281	snapping = FT_BOOL( ( dim == AF_DIMENSION_HORZ &&
1282	AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) \|\|
1283	( dim == AF_DIMENSION_VERT &&
1284	AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) );
1285
1286	for ( edge = edges; edge < edge_limit; edge++ )
1287	{
1288	/* move the points of each segment */
1289	/* in each edge to the edge's position */
1290	AF_Segment seg = edge->first;
1291
1292
1293	if ( snapping )
1294	{
1295	do
1296	{
1297	AF_Point point = seg->first;
1298
1299
1300	for (;;)
1301	{
1302	if ( dim == AF_DIMENSION_HORZ )
1303	{
1304	point->x = edge->pos;
1305	point->flags \|= AF_FLAG_TOUCH_X;
1306	}
1307	else
1308	{
1309	point->y = edge->pos;
1310	point->flags \|= AF_FLAG_TOUCH_Y;
1311	}
1312
1313	if ( point == seg->last )
1314	break;
1315
1316	point = point->next;
1317	}
1318
1319	seg = seg->edge_next;
1320
1321	} while ( seg != edge->first );
1322	}
1323	else
1324	{
1325	FT_Pos delta = edge->pos - edge->opos;
1326
1327
1328	do
1329	{
1330	AF_Point point = seg->first;
1331
1332
1333	for (;;)
1334	{
1335	if ( dim == AF_DIMENSION_HORZ )
1336	{
1337	point->x += delta;
1338	point->flags \|= AF_FLAG_TOUCH_X;
1339	}
1340	else
1341	{
1342	point->y += delta;
1343	point->flags \|= AF_FLAG_TOUCH_Y;
1344	}
1345
1346	if ( point == seg->last )
1347	break;
1348
1349	point = point->next;
1350	}
1351
1352	seg = seg->edge_next;
1353
1354	} while ( seg != edge->first );
1355	}
1356	}
1357	}
1358
1359
1360	FT_LOCAL_DEF( FT_Error )
1361	af_cjk_hints_apply( AF_GlyphHints hints,
1362	FT_Outline* outline,
1363	AF_LatinMetrics metrics )
1364	{
1365	FT_Error error;
1366	int dim;
1367
1368	FT_UNUSED( metrics );
1369
1370
1371	error = af_glyph_hints_reload( hints, outline, 0 );
1372	if ( error )
1373	goto Exit;
1374
1375	/* analyze glyph outline */
1376	if ( AF_HINTS_DO_HORIZONTAL( hints ) )
1377	{
1378	error = af_cjk_hints_detect_features( hints, AF_DIMENSION_HORZ );
1379	if ( error )
1380	goto Exit;
1381	}
1382
1383	if ( AF_HINTS_DO_VERTICAL( hints ) )
1384	{
1385	error = af_cjk_hints_detect_features( hints, AF_DIMENSION_VERT );
1386	if ( error )
1387	goto Exit;
1388	}
1389
1390	/* grid-fit the outline */
1391	for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
1392	{
1393	if ( ( dim == AF_DIMENSION_HORZ && AF_HINTS_DO_HORIZONTAL( hints ) ) \|\|
1394	( dim == AF_DIMENSION_VERT && AF_HINTS_DO_VERTICAL( hints ) ) )
1395	{
1396
1397	#ifdef AF_USE_WARPER
1398	if ( dim == AF_DIMENSION_HORZ &&
1399	metrics->root.scaler.render_mode == FT_RENDER_MODE_NORMAL )
1400	{
1401	AF_WarperRec warper;
1402	FT_Fixed scale;
1403	FT_Pos delta;
1404
1405
1406	af_warper_compute( &warper, hints, dim, &scale, &delta );
1407	af_glyph_hints_scale_dim( hints, dim, scale, delta );
1408	continue;
1409	}
1410	#endif /* AF_USE_WARPER */
1411
1412	af_cjk_hint_edges( hints, (AF_Dimension)dim );
1413	af_cjk_align_edge_points( hints, (AF_Dimension)dim );
1414	af_glyph_hints_align_strong_points( hints, (AF_Dimension)dim );
1415	af_glyph_hints_align_weak_points( hints, (AF_Dimension)dim );
1416	}
1417	}
1418
1419	#if 0
1420	af_glyph_hints_dump_points( hints );
1421	af_glyph_hints_dump_segments( hints );
1422	af_glyph_hints_dump_edges( hints );
1423	#endif
1424
1425	af_glyph_hints_save( hints, outline );
1426
1427	Exit:
1428	return error;
1429	}
1430
1431
1432	/*************************************************************************/
1433	/*************************************************************************/
1434	/*** ***/
1435	/*** C J K S C R I P T C L A S S ***/
1436	/*** ***/
1437	/*************************************************************************/
1438	/*************************************************************************/
1439
1440
1441	static const AF_Script_UniRangeRec af_cjk_uniranges[] =
1442	{
1443	#if 0
1444	{ 0x0100UL, 0xFFFFUL }, /* why this? */
1445	#endif
1446	{ 0x2E80UL, 0x2EFFUL }, /* CJK Radicals Supplement */
1447	{ 0x2F00UL, 0x2FDFUL }, /* Kangxi Radicals */
1448	{ 0x3000UL, 0x303FUL }, /* CJK Symbols and Punctuation */
1449	{ 0x3040UL, 0x309FUL }, /* Hiragana */
1450	{ 0x30A0UL, 0x30FFUL }, /* Katakana */
1451	{ 0x3100UL, 0x312FUL }, /* Bopomofo */
1452	{ 0x3130UL, 0x318FUL }, /* Hangul Compatibility Jamo */
1453	{ 0x31A0UL, 0x31BFUL }, /* Bopomofo Extended */
1454	{ 0x31C0UL, 0x31EFUL }, /* CJK Strokes */
1455	{ 0x31F0UL, 0x31FFUL }, /* Katakana Phonetic Extensions */
1456	{ 0x3200UL, 0x32FFUL }, /* Enclosed CJK Letters and Months */
1457	{ 0x3300UL, 0x33FFUL }, /* CJK Compatibility */
1458	{ 0x3400UL, 0x4DBFUL }, /* CJK Unified Ideographs Extension A */
1459	{ 0x4DC0UL, 0x4DFFUL }, /* Yijing Hexagram Symbols */
1460	{ 0x4E00UL, 0x9FFFUL }, /* CJK Unified Ideographs */
1461	{ 0xF900UL, 0xFAFFUL }, /* CJK Compatibility Ideographs */
1462	{ 0xFE30UL, 0xFE4FUL }, /* CJK Compatibility Forms */
1463	{ 0xFF00UL, 0xFFEFUL }, /* Halfwidth and Fullwidth Forms */
1464	{ 0x20000UL, 0x2A6DFUL }, /* CJK Unified Ideographs Extension B */
1465	{ 0x2F800UL, 0x2FA1FUL }, /* CJK Compatibility Ideographs Supplement */
1466	{ 0UL, 0UL }
1467	};
1468
1469
1470	FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec
1471	af_cjk_script_class =
1472	{
1473	AF_SCRIPT_CJK,
1474	af_cjk_uniranges,
1475
1476	sizeof( AF_LatinMetricsRec ),
1477
1478	(AF_Script_InitMetricsFunc) af_cjk_metrics_init,
1479	(AF_Script_ScaleMetricsFunc)af_cjk_metrics_scale,
1480	(AF_Script_DoneMetricsFunc) NULL,
1481
1482	(AF_Script_InitHintsFunc) af_cjk_hints_init,
1483	(AF_Script_ApplyHintsFunc) af_cjk_hints_apply
1484	};
1485
1486	#else /* !AF_CONFIG_OPTION_CJK */
1487
1488	static const AF_Script_UniRangeRec af_cjk_uniranges[] =
1489	{
1490	{ 0, 0 }
1491	};
1492
1493
1494	FT_CALLBACK_TABLE_DEF const AF_ScriptClassRec
1495	af_cjk_script_class =
1496	{
1497	AF_SCRIPT_CJK,
1498	af_cjk_uniranges,
1499
1500	sizeof( AF_LatinMetricsRec ),
1501
1502	(AF_Script_InitMetricsFunc) NULL,
1503	(AF_Script_ScaleMetricsFunc)NULL,
1504	(AF_Script_DoneMetricsFunc) NULL,
1505
1506	(AF_Script_InitHintsFunc) NULL,
1507	(AF_Script_ApplyHintsFunc) NULL
1508	};
1509
1510	#endif /* !AF_CONFIG_OPTION_CJK */
1511
1512
1513	/* END */

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