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[reactos.git] / lib / 3rdparty / freetype / src / pshinter / pshalgo.c
1 /***************************************************************************/
2 /* */
3 /* pshalgo.c */
4 /* */
5 /* PostScript hinting algorithm (body). */
6 /* */
7 /* Copyright 2001, 2002, 2003, 2004, 2005, 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 #include <ft2build.h>
20 #include FT_INTERNAL_OBJECTS_H
21 #include FT_INTERNAL_DEBUG_H
22 #include FT_INTERNAL_CALC_H
23 #include "pshalgo.h"
24
25 #include "pshnterr.h"
26
27
28 #undef FT_COMPONENT
29 #define FT_COMPONENT trace_pshalgo2
30
31
32 #ifdef DEBUG_HINTER
33 PSH_Hint_Table ps_debug_hint_table = 0;
34 PSH_HintFunc ps_debug_hint_func = 0;
35 PSH_Glyph ps_debug_glyph = 0;
36 #endif
37
38
39 #define COMPUTE_INFLEXS /* compute inflection points to optimize `S' */
40 /* and similar glyphs */
41 #define STRONGER /* slightly increase the contrast of smooth */
42 /* hinting */
43
44
45 /*************************************************************************/
46 /*************************************************************************/
47 /***** *****/
48 /***** BASIC HINTS RECORDINGS *****/
49 /***** *****/
50 /*************************************************************************/
51 /*************************************************************************/
52
53 /* return true if two stem hints overlap */
54 static FT_Int
55 psh_hint_overlap( PSH_Hint hint1,
56 PSH_Hint hint2 )
57 {
58 return hint1->org_pos + hint1->org_len >= hint2->org_pos &&
59 hint2->org_pos + hint2->org_len >= hint1->org_pos;
60 }
61
62
63 /* destroy hints table */
64 static void
65 psh_hint_table_done( PSH_Hint_Table table,
66 FT_Memory memory )
67 {
68 FT_FREE( table->zones );
69 table->num_zones = 0;
70 table->zone = 0;
71
72 FT_FREE( table->sort );
73 FT_FREE( table->hints );
74 table->num_hints = 0;
75 table->max_hints = 0;
76 table->sort_global = 0;
77 }
78
79
80 /* deactivate all hints in a table */
81 static void
82 psh_hint_table_deactivate( PSH_Hint_Table table )
83 {
84 FT_UInt count = table->max_hints;
85 PSH_Hint hint = table->hints;
86
87
88 for ( ; count > 0; count--, hint++ )
89 {
90 psh_hint_deactivate( hint );
91 hint->order = -1;
92 }
93 }
94
95
96 /* internal function to record a new hint */
97 static void
98 psh_hint_table_record( PSH_Hint_Table table,
99 FT_UInt idx )
100 {
101 PSH_Hint hint = table->hints + idx;
102
103
104 if ( idx >= table->max_hints )
105 {
106 FT_TRACE0(( "psh_hint_table_record: invalid hint index %d\n", idx ));
107 return;
108 }
109
110 /* ignore active hints */
111 if ( psh_hint_is_active( hint ) )
112 return;
113
114 psh_hint_activate( hint );
115
116 /* now scan the current active hint set to check */
117 /* whether `hint' overlaps with another hint */
118 {
119 PSH_Hint* sorted = table->sort_global;
120 FT_UInt count = table->num_hints;
121 PSH_Hint hint2;
122
123
124 hint->parent = 0;
125 for ( ; count > 0; count--, sorted++ )
126 {
127 hint2 = sorted[0];
128
129 if ( psh_hint_overlap( hint, hint2 ) )
130 {
131 hint->parent = hint2;
132 break;
133 }
134 }
135 }
136
137 if ( table->num_hints < table->max_hints )
138 table->sort_global[table->num_hints++] = hint;
139 else
140 FT_TRACE0(( "psh_hint_table_record: too many sorted hints! BUG!\n" ));
141 }
142
143
144 static void
145 psh_hint_table_record_mask( PSH_Hint_Table table,
146 PS_Mask hint_mask )
147 {
148 FT_Int mask = 0, val = 0;
149 FT_Byte* cursor = hint_mask->bytes;
150 FT_UInt idx, limit;
151
152
153 limit = hint_mask->num_bits;
154
155 for ( idx = 0; idx < limit; idx++ )
156 {
157 if ( mask == 0 )
158 {
159 val = *cursor++;
160 mask = 0x80;
161 }
162
163 if ( val & mask )
164 psh_hint_table_record( table, idx );
165
166 mask >>= 1;
167 }
168 }
169
170
171 /* create hints table */
172 static FT_Error
173 psh_hint_table_init( PSH_Hint_Table table,
174 PS_Hint_Table hints,
175 PS_Mask_Table hint_masks,
176 PS_Mask_Table counter_masks,
177 FT_Memory memory )
178 {
179 FT_UInt count;
180 FT_Error error;
181
182 FT_UNUSED( counter_masks );
183
184
185 count = hints->num_hints;
186
187 /* allocate our tables */
188 if ( FT_NEW_ARRAY( table->sort, 2 * count ) ||
189 FT_NEW_ARRAY( table->hints, count ) ||
190 FT_NEW_ARRAY( table->zones, 2 * count + 1 ) )
191 goto Exit;
192
193 table->max_hints = count;
194 table->sort_global = table->sort + count;
195 table->num_hints = 0;
196 table->num_zones = 0;
197 table->zone = 0;
198
199 /* initialize the `table->hints' array */
200 {
201 PSH_Hint write = table->hints;
202 PS_Hint read = hints->hints;
203
204
205 for ( ; count > 0; count--, write++, read++ )
206 {
207 write->org_pos = read->pos;
208 write->org_len = read->len;
209 write->flags = read->flags;
210 }
211 }
212
213 /* we now need to determine the initial `parent' stems; first */
214 /* activate the hints that are given by the initial hint masks */
215 if ( hint_masks )
216 {
217 PS_Mask mask = hint_masks->masks;
218
219
220 count = hint_masks->num_masks;
221 table->hint_masks = hint_masks;
222
223 for ( ; count > 0; count--, mask++ )
224 psh_hint_table_record_mask( table, mask );
225 }
226
227 /* finally, do a linear parse in case some hints were left alone */
228 if ( table->num_hints != table->max_hints )
229 {
230 FT_UInt idx;
231
232
233 FT_TRACE0(( "psh_hint_table_init: missing/incorrect hint masks\n" ));
234
235 count = table->max_hints;
236 for ( idx = 0; idx < count; idx++ )
237 psh_hint_table_record( table, idx );
238 }
239
240 Exit:
241 return error;
242 }
243
244
245 static void
246 psh_hint_table_activate_mask( PSH_Hint_Table table,
247 PS_Mask hint_mask )
248 {
249 FT_Int mask = 0, val = 0;
250 FT_Byte* cursor = hint_mask->bytes;
251 FT_UInt idx, limit, count;
252
253
254 limit = hint_mask->num_bits;
255 count = 0;
256
257 psh_hint_table_deactivate( table );
258
259 for ( idx = 0; idx < limit; idx++ )
260 {
261 if ( mask == 0 )
262 {
263 val = *cursor++;
264 mask = 0x80;
265 }
266
267 if ( val & mask )
268 {
269 PSH_Hint hint = &table->hints[idx];
270
271
272 if ( !psh_hint_is_active( hint ) )
273 {
274 FT_UInt count2;
275
276 #if 0
277 PSH_Hint* sort = table->sort;
278 PSH_Hint hint2;
279
280
281 for ( count2 = count; count2 > 0; count2--, sort++ )
282 {
283 hint2 = sort[0];
284 if ( psh_hint_overlap( hint, hint2 ) )
285 FT_TRACE0(( "psh_hint_table_activate_mask:"
286 " found overlapping hints\n" ))
287 }
288 #else
289 count2 = 0;
290 #endif
291
292 if ( count2 == 0 )
293 {
294 psh_hint_activate( hint );
295 if ( count < table->max_hints )
296 table->sort[count++] = hint;
297 else
298 FT_TRACE0(( "psh_hint_tableactivate_mask:"
299 " too many active hints\n" ));
300 }
301 }
302 }
303
304 mask >>= 1;
305 }
306 table->num_hints = count;
307
308 /* now, sort the hints; they are guaranteed to not overlap */
309 /* so we can compare their "org_pos" field directly */
310 {
311 FT_Int i1, i2;
312 PSH_Hint hint1, hint2;
313 PSH_Hint* sort = table->sort;
314
315
316 /* a simple bubble sort will do, since in 99% of cases, the hints */
317 /* will be already sorted -- and the sort will be linear */
318 for ( i1 = 1; i1 < (FT_Int)count; i1++ )
319 {
320 hint1 = sort[i1];
321 for ( i2 = i1 - 1; i2 >= 0; i2-- )
322 {
323 hint2 = sort[i2];
324
325 if ( hint2->org_pos < hint1->org_pos )
326 break;
327
328 sort[i2 + 1] = hint2;
329 sort[i2] = hint1;
330 }
331 }
332 }
333 }
334
335
336 /*************************************************************************/
337 /*************************************************************************/
338 /***** *****/
339 /***** HINTS GRID-FITTING AND OPTIMIZATION *****/
340 /***** *****/
341 /*************************************************************************/
342 /*************************************************************************/
343
344 #if 1
345 static FT_Pos
346 psh_dimension_quantize_len( PSH_Dimension dim,
347 FT_Pos len,
348 FT_Bool do_snapping )
349 {
350 if ( len <= 64 )
351 len = 64;
352 else
353 {
354 FT_Pos delta = len - dim->stdw.widths[0].cur;
355
356
357 if ( delta < 0 )
358 delta = -delta;
359
360 if ( delta < 40 )
361 {
362 len = dim->stdw.widths[0].cur;
363 if ( len < 48 )
364 len = 48;
365 }
366
367 if ( len < 3 * 64 )
368 {
369 delta = ( len & 63 );
370 len &= -64;
371
372 if ( delta < 10 )
373 len += delta;
374
375 else if ( delta < 32 )
376 len += 10;
377
378 else if ( delta < 54 )
379 len += 54;
380
381 else
382 len += delta;
383 }
384 else
385 len = FT_PIX_ROUND( len );
386 }
387
388 if ( do_snapping )
389 len = FT_PIX_ROUND( len );
390
391 return len;
392 }
393 #endif /* 0 */
394
395
396 #ifdef DEBUG_HINTER
397
398 static void
399 ps_simple_scale( PSH_Hint_Table table,
400 FT_Fixed scale,
401 FT_Fixed delta,
402 FT_Int dimension )
403 {
404 PSH_Hint hint;
405 FT_UInt count;
406
407
408 for ( count = 0; count < table->max_hints; count++ )
409 {
410 hint = table->hints + count;
411
412 hint->cur_pos = FT_MulFix( hint->org_pos, scale ) + delta;
413 hint->cur_len = FT_MulFix( hint->org_len, scale );
414
415 if ( ps_debug_hint_func )
416 ps_debug_hint_func( hint, dimension );
417 }
418 }
419
420 #endif /* DEBUG_HINTER */
421
422
423 static FT_Fixed
424 psh_hint_snap_stem_side_delta( FT_Fixed pos,
425 FT_Fixed len )
426 {
427 FT_Fixed delta1 = FT_PIX_ROUND( pos ) - pos;
428 FT_Fixed delta2 = FT_PIX_ROUND( pos + len ) - pos - len;
429
430
431 if ( FT_ABS( delta1 ) <= FT_ABS( delta2 ) )
432 return delta1;
433 else
434 return delta2;
435 }
436
437
438 static void
439 psh_hint_align( PSH_Hint hint,
440 PSH_Globals globals,
441 FT_Int dimension,
442 PSH_Glyph glyph )
443 {
444 PSH_Dimension dim = &globals->dimension[dimension];
445 FT_Fixed scale = dim->scale_mult;
446 FT_Fixed delta = dim->scale_delta;
447
448
449 if ( !psh_hint_is_fitted( hint ) )
450 {
451 FT_Pos pos = FT_MulFix( hint->org_pos, scale ) + delta;
452 FT_Pos len = FT_MulFix( hint->org_len, scale );
453
454 FT_Int do_snapping;
455 FT_Pos fit_len;
456 PSH_AlignmentRec align;
457
458
459 /* ignore stem alignments when requested through the hint flags */
460 if ( ( dimension == 0 && !glyph->do_horz_hints ) ||
461 ( dimension == 1 && !glyph->do_vert_hints ) )
462 {
463 hint->cur_pos = pos;
464 hint->cur_len = len;
465
466 psh_hint_set_fitted( hint );
467 return;
468 }
469
470 /* perform stem snapping when requested - this is necessary
471 * for monochrome and LCD hinting modes only
472 */
473 do_snapping = ( dimension == 0 && glyph->do_horz_snapping ) ||
474 ( dimension == 1 && glyph->do_vert_snapping );
475
476 hint->cur_len = fit_len = len;
477
478 /* check blue zones for horizontal stems */
479 align.align = PSH_BLUE_ALIGN_NONE;
480 align.align_bot = align.align_top = 0;
481
482 if ( dimension == 1 )
483 psh_blues_snap_stem( &globals->blues,
484 hint->org_pos + hint->org_len,
485 hint->org_pos,
486 &align );
487
488 switch ( align.align )
489 {
490 case PSH_BLUE_ALIGN_TOP:
491 /* the top of the stem is aligned against a blue zone */
492 hint->cur_pos = align.align_top - fit_len;
493 break;
494
495 case PSH_BLUE_ALIGN_BOT:
496 /* the bottom of the stem is aligned against a blue zone */
497 hint->cur_pos = align.align_bot;
498 break;
499
500 case PSH_BLUE_ALIGN_TOP | PSH_BLUE_ALIGN_BOT:
501 /* both edges of the stem are aligned against blue zones */
502 hint->cur_pos = align.align_bot;
503 hint->cur_len = align.align_top - align.align_bot;
504 break;
505
506 default:
507 {
508 PSH_Hint parent = hint->parent;
509
510
511 if ( parent )
512 {
513 FT_Pos par_org_center, par_cur_center;
514 FT_Pos cur_org_center, cur_delta;
515
516
517 /* ensure that parent is already fitted */
518 if ( !psh_hint_is_fitted( parent ) )
519 psh_hint_align( parent, globals, dimension, glyph );
520
521 /* keep original relation between hints, this is, use the */
522 /* scaled distance between the centers of the hints to */
523 /* compute the new position */
524 par_org_center = parent->org_pos + ( parent->org_len >> 1 );
525 par_cur_center = parent->cur_pos + ( parent->cur_len >> 1 );
526 cur_org_center = hint->org_pos + ( hint->org_len >> 1 );
527
528 cur_delta = FT_MulFix( cur_org_center - par_org_center, scale );
529 pos = par_cur_center + cur_delta - ( len >> 1 );
530 }
531
532 hint->cur_pos = pos;
533 hint->cur_len = fit_len;
534
535 /* Stem adjustment tries to snap stem widths to standard
536 * ones. This is important to prevent unpleasant rounding
537 * artefacts.
538 */
539 if ( glyph->do_stem_adjust )
540 {
541 if ( len <= 64 )
542 {
543 /* the stem is less than one pixel; we will center it
544 * around the nearest pixel center
545 */
546 if ( len >= 32 )
547 {
548 /* This is a special case where we also widen the stem
549 * and align it to the pixel grid.
550 *
551 * stem_center = pos + (len/2)
552 * nearest_pixel_center = FT_ROUND(stem_center-32)+32
553 * new_pos = nearest_pixel_center-32
554 * = FT_ROUND(stem_center-32)
555 * = FT_FLOOR(stem_center-32+32)
556 * = FT_FLOOR(stem_center)
557 * new_len = 64
558 */
559 pos = FT_PIX_FLOOR( pos + ( len >> 1 ) );
560 len = 64;
561 }
562 else if ( len > 0 )
563 {
564 /* This is a very small stem; we simply align it to the
565 * pixel grid, trying to find the minimal displacement.
566 *
567 * left = pos
568 * right = pos + len
569 * left_nearest_edge = ROUND(pos)
570 * right_nearest_edge = ROUND(right)
571 *
572 * if ( ABS(left_nearest_edge - left) <=
573 * ABS(right_nearest_edge - right) )
574 * new_pos = left
575 * else
576 * new_pos = right
577 */
578 FT_Pos left_nearest = FT_PIX_ROUND( pos );
579 FT_Pos right_nearest = FT_PIX_ROUND( pos + len );
580 FT_Pos left_disp = left_nearest - pos;
581 FT_Pos right_disp = right_nearest - ( pos + len );
582
583
584 if ( left_disp < 0 )
585 left_disp = -left_disp;
586 if ( right_disp < 0 )
587 right_disp = -right_disp;
588 if ( left_disp <= right_disp )
589 pos = left_nearest;
590 else
591 pos = right_nearest;
592 }
593 else
594 {
595 /* this is a ghost stem; we simply round it */
596 pos = FT_PIX_ROUND( pos );
597 }
598 }
599 else
600 {
601 len = psh_dimension_quantize_len( dim, len, 0 );
602 }
603 }
604
605 /* now that we have a good hinted stem width, try to position */
606 /* the stem along a pixel grid integer coordinate */
607 hint->cur_pos = pos + psh_hint_snap_stem_side_delta( pos, len );
608 hint->cur_len = len;
609 }
610 }
611
612 if ( do_snapping )
613 {
614 pos = hint->cur_pos;
615 len = hint->cur_len;
616
617 if ( len < 64 )
618 len = 64;
619 else
620 len = FT_PIX_ROUND( len );
621
622 switch ( align.align )
623 {
624 case PSH_BLUE_ALIGN_TOP:
625 hint->cur_pos = align.align_top - len;
626 hint->cur_len = len;
627 break;
628
629 case PSH_BLUE_ALIGN_BOT:
630 hint->cur_len = len;
631 break;
632
633 case PSH_BLUE_ALIGN_BOT | PSH_BLUE_ALIGN_TOP:
634 /* don't touch */
635 break;
636
637
638 default:
639 hint->cur_len = len;
640 if ( len & 64 )
641 pos = FT_PIX_FLOOR( pos + ( len >> 1 ) ) + 32;
642 else
643 pos = FT_PIX_ROUND( pos + ( len >> 1 ) );
644
645 hint->cur_pos = pos - ( len >> 1 );
646 hint->cur_len = len;
647 }
648 }
649
650 psh_hint_set_fitted( hint );
651
652 #ifdef DEBUG_HINTER
653 if ( ps_debug_hint_func )
654 ps_debug_hint_func( hint, dimension );
655 #endif
656 }
657 }
658
659
660 #if 0 /* not used for now, experimental */
661
662 /*
663 * A variant to perform "light" hinting (i.e. FT_RENDER_MODE_LIGHT)
664 * of stems
665 */
666 static void
667 psh_hint_align_light( PSH_Hint hint,
668 PSH_Globals globals,
669 FT_Int dimension,
670 PSH_Glyph glyph )
671 {
672 PSH_Dimension dim = &globals->dimension[dimension];
673 FT_Fixed scale = dim->scale_mult;
674 FT_Fixed delta = dim->scale_delta;
675
676
677 if ( !psh_hint_is_fitted( hint ) )
678 {
679 FT_Pos pos = FT_MulFix( hint->org_pos, scale ) + delta;
680 FT_Pos len = FT_MulFix( hint->org_len, scale );
681
682 FT_Pos fit_len;
683
684 PSH_AlignmentRec align;
685
686
687 /* ignore stem alignments when requested through the hint flags */
688 if ( ( dimension == 0 && !glyph->do_horz_hints ) ||
689 ( dimension == 1 && !glyph->do_vert_hints ) )
690 {
691 hint->cur_pos = pos;
692 hint->cur_len = len;
693
694 psh_hint_set_fitted( hint );
695 return;
696 }
697
698 fit_len = len;
699
700 hint->cur_len = fit_len;
701
702 /* check blue zones for horizontal stems */
703 align.align = PSH_BLUE_ALIGN_NONE;
704 align.align_bot = align.align_top = 0;
705
706 if ( dimension == 1 )
707 psh_blues_snap_stem( &globals->blues,
708 hint->org_pos + hint->org_len,
709 hint->org_pos,
710 &align );
711
712 switch ( align.align )
713 {
714 case PSH_BLUE_ALIGN_TOP:
715 /* the top of the stem is aligned against a blue zone */
716 hint->cur_pos = align.align_top - fit_len;
717 break;
718
719 case PSH_BLUE_ALIGN_BOT:
720 /* the bottom of the stem is aligned against a blue zone */
721 hint->cur_pos = align.align_bot;
722 break;
723
724 case PSH_BLUE_ALIGN_TOP | PSH_BLUE_ALIGN_BOT:
725 /* both edges of the stem are aligned against blue zones */
726 hint->cur_pos = align.align_bot;
727 hint->cur_len = align.align_top - align.align_bot;
728 break;
729
730 default:
731 {
732 PSH_Hint parent = hint->parent;
733
734
735 if ( parent )
736 {
737 FT_Pos par_org_center, par_cur_center;
738 FT_Pos cur_org_center, cur_delta;
739
740
741 /* ensure that parent is already fitted */
742 if ( !psh_hint_is_fitted( parent ) )
743 psh_hint_align_light( parent, globals, dimension, glyph );
744
745 par_org_center = parent->org_pos + ( parent->org_len / 2 );
746 par_cur_center = parent->cur_pos + ( parent->cur_len / 2 );
747 cur_org_center = hint->org_pos + ( hint->org_len / 2 );
748
749 cur_delta = FT_MulFix( cur_org_center - par_org_center, scale );
750 pos = par_cur_center + cur_delta - ( len >> 1 );
751 }
752
753 /* Stems less than one pixel wide are easy -- we want to
754 * make them as dark as possible, so they must fall within
755 * one pixel. If the stem is split between two pixels
756 * then snap the edge that is nearer to the pixel boundary
757 * to the pixel boundary.
758 */
759 if ( len <= 64 )
760 {
761 if ( ( pos + len + 63 ) / 64 != pos / 64 + 1 )
762 pos += psh_hint_snap_stem_side_delta ( pos, len );
763 }
764
765 /* Position stems other to minimize the amount of mid-grays.
766 * There are, in general, two positions that do this,
767 * illustrated as A) and B) below.
768 *
769 * + + + +
770 *
771 * A) |--------------------------------|
772 * B) |--------------------------------|
773 * C) |--------------------------------|
774 *
775 * Position A) (split the excess stem equally) should be better
776 * for stems of width N + f where f < 0.5.
777 *
778 * Position B) (split the deficiency equally) should be better
779 * for stems of width N + f where f > 0.5.
780 *
781 * It turns out though that minimizing the total number of lit
782 * pixels is also important, so position C), with one edge
783 * aligned with a pixel boundary is actually preferable
784 * to A). There are also more possibile positions for C) than
785 * for A) or B), so it involves less distortion of the overall
786 * character shape.
787 */
788 else /* len > 64 */
789 {
790 FT_Fixed frac_len = len & 63;
791 FT_Fixed center = pos + ( len >> 1 );
792 FT_Fixed delta_a, delta_b;
793
794
795 if ( ( len / 64 ) & 1 )
796 {
797 delta_a = FT_PIX_FLOOR( center ) + 32 - center;
798 delta_b = FT_PIX_ROUND( center ) - center;
799 }
800 else
801 {
802 delta_a = FT_PIX_ROUND( center ) - center;
803 delta_b = FT_PIX_FLOOR( center ) + 32 - center;
804 }
805
806 /* We choose between B) and C) above based on the amount
807 * of fractinal stem width; for small amounts, choose
808 * C) always, for large amounts, B) always, and inbetween,
809 * pick whichever one involves less stem movement.
810 */
811 if ( frac_len < 32 )
812 {
813 pos += psh_hint_snap_stem_side_delta ( pos, len );
814 }
815 else if ( frac_len < 48 )
816 {
817 FT_Fixed side_delta = psh_hint_snap_stem_side_delta ( pos,
818 len );
819
820 if ( FT_ABS( side_delta ) < FT_ABS( delta_b ) )
821 pos += side_delta;
822 else
823 pos += delta_b;
824 }
825 else
826 {
827 pos += delta_b;
828 }
829 }
830
831 hint->cur_pos = pos;
832 }
833 } /* switch */
834
835 psh_hint_set_fitted( hint );
836
837 #ifdef DEBUG_HINTER
838 if ( ps_debug_hint_func )
839 ps_debug_hint_func( hint, dimension );
840 #endif
841 }
842 }
843
844 #endif /* 0 */
845
846
847 static void
848 psh_hint_table_align_hints( PSH_Hint_Table table,
849 PSH_Globals globals,
850 FT_Int dimension,
851 PSH_Glyph glyph )
852 {
853 PSH_Hint hint;
854 FT_UInt count;
855
856 #ifdef DEBUG_HINTER
857
858 PSH_Dimension dim = &globals->dimension[dimension];
859 FT_Fixed scale = dim->scale_mult;
860 FT_Fixed delta = dim->scale_delta;
861
862
863 if ( ps_debug_no_vert_hints && dimension == 0 )
864 {
865 ps_simple_scale( table, scale, delta, dimension );
866 return;
867 }
868
869 if ( ps_debug_no_horz_hints && dimension == 1 )
870 {
871 ps_simple_scale( table, scale, delta, dimension );
872 return;
873 }
874
875 #endif /* DEBUG_HINTER*/
876
877 hint = table->hints;
878 count = table->max_hints;
879
880 for ( ; count > 0; count--, hint++ )
881 psh_hint_align( hint, globals, dimension, glyph );
882 }
883
884
885 /*************************************************************************/
886 /*************************************************************************/
887 /***** *****/
888 /***** POINTS INTERPOLATION ROUTINES *****/
889 /***** *****/
890 /*************************************************************************/
891 /*************************************************************************/
892
893 #define PSH_ZONE_MIN -3200000L
894 #define PSH_ZONE_MAX +3200000L
895
896 #define xxDEBUG_ZONES
897
898
899 #ifdef DEBUG_ZONES
900
901 #include FT_CONFIG_STANDARD_LIBRARY_H
902
903 static void
904 psh_print_zone( PSH_Zone zone )
905 {
906 printf( "zone [scale,delta,min,max] = [%.3f,%.3f,%d,%d]\n",
907 zone->scale / 65536.0,
908 zone->delta / 64.0,
909 zone->min,
910 zone->max );
911 }
912
913 #else
914
915 #define psh_print_zone( x ) do { } while ( 0 )
916
917 #endif /* DEBUG_ZONES */
918
919
920 /*************************************************************************/
921 /*************************************************************************/
922 /***** *****/
923 /***** HINTER GLYPH MANAGEMENT *****/
924 /***** *****/
925 /*************************************************************************/
926 /*************************************************************************/
927
928 #if 1
929
930 #define psh_corner_is_flat ft_corner_is_flat
931 #define psh_corner_orientation ft_corner_orientation
932
933 #else
934
935 FT_LOCAL_DEF( FT_Int )
936 psh_corner_is_flat( FT_Pos x_in,
937 FT_Pos y_in,
938 FT_Pos x_out,
939 FT_Pos y_out )
940 {
941 FT_Pos ax = x_in;
942 FT_Pos ay = y_in;
943
944 FT_Pos d_in, d_out, d_corner;
945
946
947 if ( ax < 0 )
948 ax = -ax;
949 if ( ay < 0 )
950 ay = -ay;
951 d_in = ax + ay;
952
953 ax = x_out;
954 if ( ax < 0 )
955 ax = -ax;
956 ay = y_out;
957 if ( ay < 0 )
958 ay = -ay;
959 d_out = ax + ay;
960
961 ax = x_out + x_in;
962 if ( ax < 0 )
963 ax = -ax;
964 ay = y_out + y_in;
965 if ( ay < 0 )
966 ay = -ay;
967 d_corner = ax + ay;
968
969 return ( d_in + d_out - d_corner ) < ( d_corner >> 4 );
970 }
971
972 static FT_Int
973 psh_corner_orientation( FT_Pos in_x,
974 FT_Pos in_y,
975 FT_Pos out_x,
976 FT_Pos out_y )
977 {
978 FT_Int result;
979
980
981 /* deal with the trivial cases quickly */
982 if ( in_y == 0 )
983 {
984 if ( in_x >= 0 )
985 result = out_y;
986 else
987 result = -out_y;
988 }
989 else if ( in_x == 0 )
990 {
991 if ( in_y >= 0 )
992 result = -out_x;
993 else
994 result = out_x;
995 }
996 else if ( out_y == 0 )
997 {
998 if ( out_x >= 0 )
999 result = in_y;
1000 else
1001 result = -in_y;
1002 }
1003 else if ( out_x == 0 )
1004 {
1005 if ( out_y >= 0 )
1006 result = -in_x;
1007 else
1008 result = in_x;
1009 }
1010 else /* general case */
1011 {
1012 long long delta = (long long)in_x * out_y - (long long)in_y * out_x;
1013
1014 if ( delta == 0 )
1015 result = 0;
1016 else
1017 result = 1 - 2 * ( delta < 0 );
1018 }
1019
1020 return result;
1021 }
1022
1023 #endif /* !1 */
1024
1025
1026 #ifdef COMPUTE_INFLEXS
1027
1028 /* compute all inflex points in a given glyph */
1029 static void
1030 psh_glyph_compute_inflections( PSH_Glyph glyph )
1031 {
1032 FT_UInt n;
1033
1034
1035 for ( n = 0; n < glyph->num_contours; n++ )
1036 {
1037 PSH_Point first, start, end, before, after;
1038 FT_Pos in_x, in_y, out_x, out_y;
1039 FT_Int orient_prev, orient_cur;
1040 FT_Int finished = 0;
1041
1042
1043 /* we need at least 4 points to create an inflection point */
1044 if ( glyph->contours[n].count < 4 )
1045 continue;
1046
1047 /* compute first segment in contour */
1048 first = glyph->contours[n].start;
1049
1050 start = end = first;
1051 do
1052 {
1053 end = end->next;
1054 if ( end == first )
1055 goto Skip;
1056
1057 in_x = end->org_u - start->org_u;
1058 in_y = end->org_v - start->org_v;
1059
1060 } while ( in_x == 0 && in_y == 0 );
1061
1062 /* extend the segment start whenever possible */
1063 before = start;
1064 do
1065 {
1066 do
1067 {
1068 start = before;
1069 before = before->prev;
1070 if ( before == first )
1071 goto Skip;
1072
1073 out_x = start->org_u - before->org_u;
1074 out_y = start->org_v - before->org_v;
1075
1076 } while ( out_x == 0 && out_y == 0 );
1077
1078 orient_prev = psh_corner_orientation( in_x, in_y, out_x, out_y );
1079
1080 } while ( orient_prev == 0 );
1081
1082 first = start;
1083 in_x = out_x;
1084 in_y = out_y;
1085
1086 /* now, process all segments in the contour */
1087 do
1088 {
1089 /* first, extend current segment's end whenever possible */
1090 after = end;
1091 do
1092 {
1093 do
1094 {
1095 end = after;
1096 after = after->next;
1097 if ( after == first )
1098 finished = 1;
1099
1100 out_x = after->org_u - end->org_u;
1101 out_y = after->org_v - end->org_v;
1102
1103 } while ( out_x == 0 && out_y == 0 );
1104
1105 orient_cur = psh_corner_orientation( in_x, in_y, out_x, out_y );
1106
1107 } while ( orient_cur == 0 );
1108
1109 if ( ( orient_cur ^ orient_prev ) < 0 )
1110 {
1111 do
1112 {
1113 psh_point_set_inflex( start );
1114 start = start->next;
1115 }
1116 while ( start != end );
1117
1118 psh_point_set_inflex( start );
1119 }
1120
1121 start = end;
1122 end = after;
1123 orient_prev = orient_cur;
1124 in_x = out_x;
1125 in_y = out_y;
1126
1127 } while ( !finished );
1128
1129 Skip:
1130 ;
1131 }
1132 }
1133
1134 #endif /* COMPUTE_INFLEXS */
1135
1136
1137 static void
1138 psh_glyph_done( PSH_Glyph glyph )
1139 {
1140 FT_Memory memory = glyph->memory;
1141
1142
1143 psh_hint_table_done( &glyph->hint_tables[1], memory );
1144 psh_hint_table_done( &glyph->hint_tables[0], memory );
1145
1146 FT_FREE( glyph->points );
1147 FT_FREE( glyph->contours );
1148
1149 glyph->num_points = 0;
1150 glyph->num_contours = 0;
1151
1152 glyph->memory = 0;
1153 }
1154
1155
1156 static int
1157 psh_compute_dir( FT_Pos dx,
1158 FT_Pos dy )
1159 {
1160 FT_Pos ax, ay;
1161 int result = PSH_DIR_NONE;
1162
1163
1164 ax = ( dx >= 0 ) ? dx : -dx;
1165 ay = ( dy >= 0 ) ? dy : -dy;
1166
1167 if ( ay * 12 < ax )
1168 {
1169 /* |dy| <<< |dx| means a near-horizontal segment */
1170 result = ( dx >= 0 ) ? PSH_DIR_RIGHT : PSH_DIR_LEFT;
1171 }
1172 else if ( ax * 12 < ay )
1173 {
1174 /* |dx| <<< |dy| means a near-vertical segment */
1175 result = ( dy >= 0 ) ? PSH_DIR_UP : PSH_DIR_DOWN;
1176 }
1177
1178 return result;
1179 }
1180
1181
1182 /* load outline point coordinates into hinter glyph */
1183 static void
1184 psh_glyph_load_points( PSH_Glyph glyph,
1185 FT_Int dimension )
1186 {
1187 FT_Vector* vec = glyph->outline->points;
1188 PSH_Point point = glyph->points;
1189 FT_UInt count = glyph->num_points;
1190
1191
1192 for ( ; count > 0; count--, point++, vec++ )
1193 {
1194 point->flags2 = 0;
1195 point->hint = NULL;
1196 if ( dimension == 0 )
1197 {
1198 point->org_u = vec->x;
1199 point->org_v = vec->y;
1200 }
1201 else
1202 {
1203 point->org_u = vec->y;
1204 point->org_v = vec->x;
1205 }
1206
1207 #ifdef DEBUG_HINTER
1208 point->org_x = vec->x;
1209 point->org_y = vec->y;
1210 #endif
1211
1212 }
1213 }
1214
1215
1216 /* save hinted point coordinates back to outline */
1217 static void
1218 psh_glyph_save_points( PSH_Glyph glyph,
1219 FT_Int dimension )
1220 {
1221 FT_UInt n;
1222 PSH_Point point = glyph->points;
1223 FT_Vector* vec = glyph->outline->points;
1224 char* tags = glyph->outline->tags;
1225
1226
1227 for ( n = 0; n < glyph->num_points; n++ )
1228 {
1229 if ( dimension == 0 )
1230 vec[n].x = point->cur_u;
1231 else
1232 vec[n].y = point->cur_u;
1233
1234 if ( psh_point_is_strong( point ) )
1235 tags[n] |= (char)( ( dimension == 0 ) ? 32 : 64 );
1236
1237 #ifdef DEBUG_HINTER
1238
1239 if ( dimension == 0 )
1240 {
1241 point->cur_x = point->cur_u;
1242 point->flags_x = point->flags2 | point->flags;
1243 }
1244 else
1245 {
1246 point->cur_y = point->cur_u;
1247 point->flags_y = point->flags2 | point->flags;
1248 }
1249
1250 #endif
1251
1252 point++;
1253 }
1254 }
1255
1256
1257 static FT_Error
1258 psh_glyph_init( PSH_Glyph glyph,
1259 FT_Outline* outline,
1260 PS_Hints ps_hints,
1261 PSH_Globals globals )
1262 {
1263 FT_Error error;
1264 FT_Memory memory;
1265
1266
1267 /* clear all fields */
1268 FT_MEM_ZERO( glyph, sizeof ( *glyph ) );
1269
1270 memory = glyph->memory = globals->memory;
1271
1272 /* allocate and setup points + contours arrays */
1273 if ( FT_NEW_ARRAY( glyph->points, outline->n_points ) ||
1274 FT_NEW_ARRAY( glyph->contours, outline->n_contours ) )
1275 goto Exit;
1276
1277 glyph->num_points = outline->n_points;
1278 glyph->num_contours = outline->n_contours;
1279
1280 {
1281 FT_UInt first = 0, next, n;
1282 PSH_Point points = glyph->points;
1283 PSH_Contour contour = glyph->contours;
1284
1285
1286 for ( n = 0; n < glyph->num_contours; n++ )
1287 {
1288 FT_Int count;
1289 PSH_Point point;
1290
1291
1292 next = outline->contours[n] + 1;
1293 count = next - first;
1294
1295 contour->start = points + first;
1296 contour->count = (FT_UInt)count;
1297
1298 if ( count > 0 )
1299 {
1300 point = points + first;
1301
1302 point->prev = points + next - 1;
1303 point->contour = contour;
1304
1305 for ( ; count > 1; count-- )
1306 {
1307 point[0].next = point + 1;
1308 point[1].prev = point;
1309 point++;
1310 point->contour = contour;
1311 }
1312 point->next = points + first;
1313 }
1314
1315 contour++;
1316 first = next;
1317 }
1318 }
1319
1320 {
1321 PSH_Point points = glyph->points;
1322 PSH_Point point = points;
1323 FT_Vector* vec = outline->points;
1324 FT_UInt n;
1325
1326
1327 for ( n = 0; n < glyph->num_points; n++, point++ )
1328 {
1329 FT_Int n_prev = (FT_Int)( point->prev - points );
1330 FT_Int n_next = (FT_Int)( point->next - points );
1331 FT_Pos dxi, dyi, dxo, dyo;
1332
1333
1334 if ( !( outline->tags[n] & FT_CURVE_TAG_ON ) )
1335 point->flags = PSH_POINT_OFF;
1336
1337 dxi = vec[n].x - vec[n_prev].x;
1338 dyi = vec[n].y - vec[n_prev].y;
1339
1340 point->dir_in = (FT_Char)psh_compute_dir( dxi, dyi );
1341
1342 dxo = vec[n_next].x - vec[n].x;
1343 dyo = vec[n_next].y - vec[n].y;
1344
1345 point->dir_out = (FT_Char)psh_compute_dir( dxo, dyo );
1346
1347 /* detect smooth points */
1348 if ( point->flags & PSH_POINT_OFF )
1349 point->flags |= PSH_POINT_SMOOTH;
1350
1351 else if ( point->dir_in == point->dir_out )
1352 {
1353 if ( point->dir_out != PSH_DIR_NONE ||
1354 psh_corner_is_flat( dxi, dyi, dxo, dyo ) )
1355 point->flags |= PSH_POINT_SMOOTH;
1356 }
1357 }
1358 }
1359
1360 glyph->outline = outline;
1361 glyph->globals = globals;
1362
1363 #ifdef COMPUTE_INFLEXS
1364 psh_glyph_load_points( glyph, 0 );
1365 psh_glyph_compute_inflections( glyph );
1366 #endif /* COMPUTE_INFLEXS */
1367
1368 /* now deal with hints tables */
1369 error = psh_hint_table_init( &glyph->hint_tables [0],
1370 &ps_hints->dimension[0].hints,
1371 &ps_hints->dimension[0].masks,
1372 &ps_hints->dimension[0].counters,
1373 memory );
1374 if ( error )
1375 goto Exit;
1376
1377 error = psh_hint_table_init( &glyph->hint_tables [1],
1378 &ps_hints->dimension[1].hints,
1379 &ps_hints->dimension[1].masks,
1380 &ps_hints->dimension[1].counters,
1381 memory );
1382 if ( error )
1383 goto Exit;
1384
1385 Exit:
1386 return error;
1387 }
1388
1389
1390 /* compute all extrema in a glyph for a given dimension */
1391 static void
1392 psh_glyph_compute_extrema( PSH_Glyph glyph )
1393 {
1394 FT_UInt n;
1395
1396
1397 /* first of all, compute all local extrema */
1398 for ( n = 0; n < glyph->num_contours; n++ )
1399 {
1400 PSH_Point first = glyph->contours[n].start;
1401 PSH_Point point, before, after;
1402
1403
1404 if ( glyph->contours[n].count == 0 )
1405 continue;
1406
1407 point = first;
1408 before = point;
1409 after = point;
1410
1411 do
1412 {
1413 before = before->prev;
1414 if ( before == first )
1415 goto Skip;
1416
1417 } while ( before->org_u == point->org_u );
1418
1419 first = point = before->next;
1420
1421 for (;;)
1422 {
1423 after = point;
1424 do
1425 {
1426 after = after->next;
1427 if ( after == first )
1428 goto Next;
1429
1430 } while ( after->org_u == point->org_u );
1431
1432 if ( before->org_u < point->org_u )
1433 {
1434 if ( after->org_u < point->org_u )
1435 {
1436 /* local maximum */
1437 goto Extremum;
1438 }
1439 }
1440 else /* before->org_u > point->org_u */
1441 {
1442 if ( after->org_u > point->org_u )
1443 {
1444 /* local minimum */
1445 Extremum:
1446 do
1447 {
1448 psh_point_set_extremum( point );
1449 point = point->next;
1450
1451 } while ( point != after );
1452 }
1453 }
1454
1455 before = after->prev;
1456 point = after;
1457
1458 } /* for */
1459
1460 Next:
1461 ;
1462 }
1463
1464 /* for each extremum, determine its direction along the */
1465 /* orthogonal axis */
1466 for ( n = 0; n < glyph->num_points; n++ )
1467 {
1468 PSH_Point point, before, after;
1469
1470
1471 point = &glyph->points[n];
1472 before = point;
1473 after = point;
1474
1475 if ( psh_point_is_extremum( point ) )
1476 {
1477 do
1478 {
1479 before = before->prev;
1480 if ( before == point )
1481 goto Skip;
1482
1483 } while ( before->org_v == point->org_v );
1484
1485 do
1486 {
1487 after = after->next;
1488 if ( after == point )
1489 goto Skip;
1490
1491 } while ( after->org_v == point->org_v );
1492 }
1493
1494 if ( before->org_v < point->org_v &&
1495 after->org_v > point->org_v )
1496 {
1497 psh_point_set_positive( point );
1498 }
1499 else if ( before->org_v > point->org_v &&
1500 after->org_v < point->org_v )
1501 {
1502 psh_point_set_negative( point );
1503 }
1504
1505 Skip:
1506 ;
1507 }
1508 }
1509
1510
1511 /* major_dir is the direction for points on the bottom/left of the stem; */
1512 /* Points on the top/right of the stem will have a direction of */
1513 /* -major_dir. */
1514
1515 static void
1516 psh_hint_table_find_strong_points( PSH_Hint_Table table,
1517 PSH_Point point,
1518 FT_UInt count,
1519 FT_Int threshold,
1520 FT_Int major_dir )
1521 {
1522 PSH_Hint* sort = table->sort;
1523 FT_UInt num_hints = table->num_hints;
1524
1525
1526 for ( ; count > 0; count--, point++ )
1527 {
1528 FT_Int point_dir = 0;
1529 FT_Pos org_u = point->org_u;
1530
1531
1532 if ( psh_point_is_strong( point ) )
1533 continue;
1534
1535 if ( PSH_DIR_COMPARE( point->dir_in, major_dir ) )
1536 point_dir = point->dir_in;
1537
1538 else if ( PSH_DIR_COMPARE( point->dir_out, major_dir ) )
1539 point_dir = point->dir_out;
1540
1541 if ( point_dir )
1542 {
1543 if ( point_dir == major_dir )
1544 {
1545 FT_UInt nn;
1546
1547
1548 for ( nn = 0; nn < num_hints; nn++ )
1549 {
1550 PSH_Hint hint = sort[nn];
1551 FT_Pos d = org_u - hint->org_pos;
1552
1553
1554 if ( d < threshold && -d < threshold )
1555 {
1556 psh_point_set_strong( point );
1557 point->flags2 |= PSH_POINT_EDGE_MIN;
1558 point->hint = hint;
1559 break;
1560 }
1561 }
1562 }
1563 else if ( point_dir == -major_dir )
1564 {
1565 FT_UInt nn;
1566
1567
1568 for ( nn = 0; nn < num_hints; nn++ )
1569 {
1570 PSH_Hint hint = sort[nn];
1571 FT_Pos d = org_u - hint->org_pos - hint->org_len;
1572
1573
1574 if ( d < threshold && -d < threshold )
1575 {
1576 psh_point_set_strong( point );
1577 point->flags2 |= PSH_POINT_EDGE_MAX;
1578 point->hint = hint;
1579 break;
1580 }
1581 }
1582 }
1583 }
1584
1585 #if 1
1586 else if ( psh_point_is_extremum( point ) )
1587 {
1588 /* treat extrema as special cases for stem edge alignment */
1589 FT_UInt nn, min_flag, max_flag;
1590
1591
1592 if ( major_dir == PSH_DIR_HORIZONTAL )
1593 {
1594 min_flag = PSH_POINT_POSITIVE;
1595 max_flag = PSH_POINT_NEGATIVE;
1596 }
1597 else
1598 {
1599 min_flag = PSH_POINT_NEGATIVE;
1600 max_flag = PSH_POINT_POSITIVE;
1601 }
1602
1603 if ( point->flags2 & min_flag )
1604 {
1605 for ( nn = 0; nn < num_hints; nn++ )
1606 {
1607 PSH_Hint hint = sort[nn];
1608 FT_Pos d = org_u - hint->org_pos;
1609
1610
1611 if ( d < threshold && -d < threshold )
1612 {
1613 point->flags2 |= PSH_POINT_EDGE_MIN;
1614 point->hint = hint;
1615 psh_point_set_strong( point );
1616 break;
1617 }
1618 }
1619 }
1620 else if ( point->flags2 & max_flag )
1621 {
1622 for ( nn = 0; nn < num_hints; nn++ )
1623 {
1624 PSH_Hint hint = sort[nn];
1625 FT_Pos d = org_u - hint->org_pos - hint->org_len;
1626
1627
1628 if ( d < threshold && -d < threshold )
1629 {
1630 point->flags2 |= PSH_POINT_EDGE_MAX;
1631 point->hint = hint;
1632 psh_point_set_strong( point );
1633 break;
1634 }
1635 }
1636 }
1637
1638 if ( point->hint == NULL )
1639 {
1640 for ( nn = 0; nn < num_hints; nn++ )
1641 {
1642 PSH_Hint hint = sort[nn];
1643
1644
1645 if ( org_u >= hint->org_pos &&
1646 org_u <= hint->org_pos + hint->org_len )
1647 {
1648 point->hint = hint;
1649 break;
1650 }
1651 }
1652 }
1653 }
1654
1655 #endif /* 1 */
1656 }
1657 }
1658
1659
1660 /* the accepted shift for strong points in fractional pixels */
1661 #define PSH_STRONG_THRESHOLD 32
1662
1663 /* the maximum shift value in font units */
1664 #define PSH_STRONG_THRESHOLD_MAXIMUM 30
1665
1666
1667 /* find strong points in a glyph */
1668 static void
1669 psh_glyph_find_strong_points( PSH_Glyph glyph,
1670 FT_Int dimension )
1671 {
1672 /* a point is `strong' if it is located on a stem edge and */
1673 /* has an `in' or `out' tangent parallel to the hint's direction */
1674
1675 PSH_Hint_Table table = &glyph->hint_tables[dimension];
1676 PS_Mask mask = table->hint_masks->masks;
1677 FT_UInt num_masks = table->hint_masks->num_masks;
1678 FT_UInt first = 0;
1679 FT_Int major_dir = dimension == 0 ? PSH_DIR_VERTICAL
1680 : PSH_DIR_HORIZONTAL;
1681 PSH_Dimension dim = &glyph->globals->dimension[dimension];
1682 FT_Fixed scale = dim->scale_mult;
1683 FT_Int threshold;
1684
1685
1686 threshold = (FT_Int)FT_DivFix( PSH_STRONG_THRESHOLD, scale );
1687 if ( threshold > PSH_STRONG_THRESHOLD_MAXIMUM )
1688 threshold = PSH_STRONG_THRESHOLD_MAXIMUM;
1689
1690 /* process secondary hints to `selected' points */
1691 if ( num_masks > 1 && glyph->num_points > 0 )
1692 {
1693 first = mask->end_point;
1694 mask++;
1695 for ( ; num_masks > 1; num_masks--, mask++ )
1696 {
1697 FT_UInt next;
1698 FT_Int count;
1699
1700
1701 next = mask->end_point;
1702 count = next - first;
1703 if ( count > 0 )
1704 {
1705 PSH_Point point = glyph->points + first;
1706
1707
1708 psh_hint_table_activate_mask( table, mask );
1709
1710 psh_hint_table_find_strong_points( table, point, count,
1711 threshold, major_dir );
1712 }
1713 first = next;
1714 }
1715 }
1716
1717 /* process primary hints for all points */
1718 if ( num_masks == 1 )
1719 {
1720 FT_UInt count = glyph->num_points;
1721 PSH_Point point = glyph->points;
1722
1723
1724 psh_hint_table_activate_mask( table, table->hint_masks->masks );
1725
1726 psh_hint_table_find_strong_points( table, point, count,
1727 threshold, major_dir );
1728 }
1729
1730 /* now, certain points may have been attached to a hint and */
1731 /* not marked as strong; update their flags then */
1732 {
1733 FT_UInt count = glyph->num_points;
1734 PSH_Point point = glyph->points;
1735
1736
1737 for ( ; count > 0; count--, point++ )
1738 if ( point->hint && !psh_point_is_strong( point ) )
1739 psh_point_set_strong( point );
1740 }
1741 }
1742
1743
1744 /* find points in a glyph which are in a blue zone and have `in' or */
1745 /* `out' tangents parallel to the horizontal axis */
1746 static void
1747 psh_glyph_find_blue_points( PSH_Blues blues,
1748 PSH_Glyph glyph )
1749 {
1750 PSH_Blue_Table table;
1751 PSH_Blue_Zone zone;
1752 FT_UInt glyph_count = glyph->num_points;
1753 FT_UInt blue_count;
1754 PSH_Point point = glyph->points;
1755
1756
1757 for ( ; glyph_count > 0; glyph_count--, point++ )
1758 {
1759 FT_Pos y;
1760
1761
1762 /* check tangents */
1763 if ( !PSH_DIR_COMPARE( point->dir_in, PSH_DIR_HORIZONTAL ) &&
1764 !PSH_DIR_COMPARE( point->dir_out, PSH_DIR_HORIZONTAL ) )
1765 continue;
1766
1767 /* skip strong points */
1768 if ( psh_point_is_strong( point ) )
1769 continue;
1770
1771 y = point->org_u;
1772
1773 /* look up top zones */
1774 table = &blues->normal_top;
1775 blue_count = table->count;
1776 zone = table->zones;
1777
1778 for ( ; blue_count > 0; blue_count--, zone++ )
1779 {
1780 FT_Pos delta = y - zone->org_bottom;
1781
1782
1783 if ( delta < -blues->blue_fuzz )
1784 break;
1785
1786 if ( y <= zone->org_top + blues->blue_fuzz )
1787 if ( blues->no_overshoots || delta <= blues->blue_threshold )
1788 {
1789 point->cur_u = zone->cur_bottom;
1790 psh_point_set_strong( point );
1791 psh_point_set_fitted( point );
1792 }
1793 }
1794
1795 /* look up bottom zones */
1796 table = &blues->normal_bottom;
1797 blue_count = table->count;
1798 zone = table->zones + blue_count - 1;
1799
1800 for ( ; blue_count > 0; blue_count--, zone-- )
1801 {
1802 FT_Pos delta = zone->org_top - y;
1803
1804
1805 if ( delta < -blues->blue_fuzz )
1806 break;
1807
1808 if ( y >= zone->org_bottom - blues->blue_fuzz )
1809 if ( blues->no_overshoots || delta < blues->blue_threshold )
1810 {
1811 point->cur_u = zone->cur_top;
1812 psh_point_set_strong( point );
1813 psh_point_set_fitted( point );
1814 }
1815 }
1816 }
1817 }
1818
1819
1820 /* interpolate strong points with the help of hinted coordinates */
1821 static void
1822 psh_glyph_interpolate_strong_points( PSH_Glyph glyph,
1823 FT_Int dimension )
1824 {
1825 PSH_Dimension dim = &glyph->globals->dimension[dimension];
1826 FT_Fixed scale = dim->scale_mult;
1827
1828 FT_UInt count = glyph->num_points;
1829 PSH_Point point = glyph->points;
1830
1831
1832 for ( ; count > 0; count--, point++ )
1833 {
1834 PSH_Hint hint = point->hint;
1835
1836
1837 if ( hint )
1838 {
1839 FT_Pos delta;
1840
1841
1842 if ( psh_point_is_edge_min( point ) )
1843 point->cur_u = hint->cur_pos;
1844
1845 else if ( psh_point_is_edge_max( point ) )
1846 point->cur_u = hint->cur_pos + hint->cur_len;
1847
1848 else
1849 {
1850 delta = point->org_u - hint->org_pos;
1851
1852 if ( delta <= 0 )
1853 point->cur_u = hint->cur_pos + FT_MulFix( delta, scale );
1854
1855 else if ( delta >= hint->org_len )
1856 point->cur_u = hint->cur_pos + hint->cur_len +
1857 FT_MulFix( delta - hint->org_len, scale );
1858
1859 else if ( hint->org_len > 0 )
1860 point->cur_u = hint->cur_pos +
1861 FT_MulDiv( delta, hint->cur_len,
1862 hint->org_len );
1863 else
1864 point->cur_u = hint->cur_pos;
1865 }
1866 psh_point_set_fitted( point );
1867 }
1868 }
1869 }
1870
1871
1872 #define PSH_MAX_STRONG_INTERNAL 16
1873
1874 static void
1875 psh_glyph_interpolate_normal_points( PSH_Glyph glyph,
1876 FT_Int dimension )
1877 {
1878
1879 #if 1
1880 /* first technique: a point is strong if it is a local extremum */
1881
1882 PSH_Dimension dim = &glyph->globals->dimension[dimension];
1883 FT_Fixed scale = dim->scale_mult;
1884 FT_Memory memory = glyph->memory;
1885
1886 PSH_Point* strongs = NULL;
1887 PSH_Point strongs_0[PSH_MAX_STRONG_INTERNAL];
1888 FT_UInt num_strongs = 0;
1889
1890 PSH_Point points = glyph->points;
1891 PSH_Point points_end = points + glyph->num_points;
1892 PSH_Point point;
1893
1894
1895 /* first count the number of strong points */
1896 for ( point = points; point < points_end; point++ )
1897 {
1898 if ( psh_point_is_strong( point ) )
1899 num_strongs++;
1900 }
1901
1902 if ( num_strongs == 0 ) /* nothing to do here */
1903 return;
1904
1905 /* allocate an array to store a list of points, */
1906 /* stored in increasing org_u order */
1907 if ( num_strongs <= PSH_MAX_STRONG_INTERNAL )
1908 strongs = strongs_0;
1909 else
1910 {
1911 FT_Error error;
1912
1913
1914 if ( FT_NEW_ARRAY( strongs, num_strongs ) )
1915 return;
1916 }
1917
1918 num_strongs = 0;
1919 for ( point = points; point < points_end; point++ )
1920 {
1921 PSH_Point* insert;
1922
1923
1924 if ( !psh_point_is_strong( point ) )
1925 continue;
1926
1927 for ( insert = strongs + num_strongs; insert > strongs; insert-- )
1928 {
1929 if ( insert[-1]->org_u <= point->org_u )
1930 break;
1931
1932 insert[0] = insert[-1];
1933 }
1934 insert[0] = point;
1935 num_strongs++;
1936 }
1937
1938 /* now try to interpolate all normal points */
1939 for ( point = points; point < points_end; point++ )
1940 {
1941 if ( psh_point_is_strong( point ) )
1942 continue;
1943
1944 /* sometimes, some local extrema are smooth points */
1945 if ( psh_point_is_smooth( point ) )
1946 {
1947 if ( point->dir_in == PSH_DIR_NONE ||
1948 point->dir_in != point->dir_out )
1949 continue;
1950
1951 if ( !psh_point_is_extremum( point ) &&
1952 !psh_point_is_inflex( point ) )
1953 continue;
1954
1955 point->flags &= ~PSH_POINT_SMOOTH;
1956 }
1957
1958 /* find best enclosing point coordinates then interpolate */
1959 {
1960 PSH_Point before, after;
1961 FT_UInt nn;
1962
1963
1964 for ( nn = 0; nn < num_strongs; nn++ )
1965 if ( strongs[nn]->org_u > point->org_u )
1966 break;
1967
1968 if ( nn == 0 ) /* point before the first strong point */
1969 {
1970 after = strongs[0];
1971
1972 point->cur_u = after->cur_u +
1973 FT_MulFix( point->org_u - after->org_u,
1974 scale );
1975 }
1976 else
1977 {
1978 before = strongs[nn - 1];
1979
1980 for ( nn = num_strongs; nn > 0; nn-- )
1981 if ( strongs[nn - 1]->org_u < point->org_u )
1982 break;
1983
1984 if ( nn == num_strongs ) /* point is after last strong point */
1985 {
1986 before = strongs[nn - 1];
1987
1988 point->cur_u = before->cur_u +
1989 FT_MulFix( point->org_u - before->org_u,
1990 scale );
1991 }
1992 else
1993 {
1994 FT_Pos u;
1995
1996
1997 after = strongs[nn];
1998
1999 /* now interpolate point between before and after */
2000 u = point->org_u;
2001
2002 if ( u == before->org_u )
2003 point->cur_u = before->cur_u;
2004
2005 else if ( u == after->org_u )
2006 point->cur_u = after->cur_u;
2007
2008 else
2009 point->cur_u = before->cur_u +
2010 FT_MulDiv( u - before->org_u,
2011 after->cur_u - before->cur_u,
2012 after->org_u - before->org_u );
2013 }
2014 }
2015 psh_point_set_fitted( point );
2016 }
2017 }
2018
2019 if ( strongs != strongs_0 )
2020 FT_FREE( strongs );
2021
2022 #endif /* 1 */
2023
2024 }
2025
2026
2027 /* interpolate other points */
2028 static void
2029 psh_glyph_interpolate_other_points( PSH_Glyph glyph,
2030 FT_Int dimension )
2031 {
2032 PSH_Dimension dim = &glyph->globals->dimension[dimension];
2033 FT_Fixed scale = dim->scale_mult;
2034 FT_Fixed delta = dim->scale_delta;
2035 PSH_Contour contour = glyph->contours;
2036 FT_UInt num_contours = glyph->num_contours;
2037
2038
2039 for ( ; num_contours > 0; num_contours--, contour++ )
2040 {
2041 PSH_Point start = contour->start;
2042 PSH_Point first, next, point;
2043 FT_UInt fit_count;
2044
2045
2046 /* count the number of strong points in this contour */
2047 next = start + contour->count;
2048 fit_count = 0;
2049 first = 0;
2050
2051 for ( point = start; point < next; point++ )
2052 if ( psh_point_is_fitted( point ) )
2053 {
2054 if ( !first )
2055 first = point;
2056
2057 fit_count++;
2058 }
2059
2060 /* if there are less than 2 fitted points in the contour, we */
2061 /* simply scale and eventually translate the contour points */
2062 if ( fit_count < 2 )
2063 {
2064 if ( fit_count == 1 )
2065 delta = first->cur_u - FT_MulFix( first->org_u, scale );
2066
2067 for ( point = start; point < next; point++ )
2068 if ( point != first )
2069 point->cur_u = FT_MulFix( point->org_u, scale ) + delta;
2070
2071 goto Next_Contour;
2072 }
2073
2074 /* there are more than 2 strong points in this contour; we */
2075 /* need to interpolate weak points between them */
2076 start = first;
2077 do
2078 {
2079 point = first;
2080
2081 /* skip consecutive fitted points */
2082 for (;;)
2083 {
2084 next = first->next;
2085 if ( next == start )
2086 goto Next_Contour;
2087
2088 if ( !psh_point_is_fitted( next ) )
2089 break;
2090
2091 first = next;
2092 }
2093
2094 /* find next fitted point after unfitted one */
2095 for (;;)
2096 {
2097 next = next->next;
2098 if ( psh_point_is_fitted( next ) )
2099 break;
2100 }
2101
2102 /* now interpolate between them */
2103 {
2104 FT_Pos org_a, org_ab, cur_a, cur_ab;
2105 FT_Pos org_c, org_ac, cur_c;
2106 FT_Fixed scale_ab;
2107
2108
2109 if ( first->org_u <= next->org_u )
2110 {
2111 org_a = first->org_u;
2112 cur_a = first->cur_u;
2113 org_ab = next->org_u - org_a;
2114 cur_ab = next->cur_u - cur_a;
2115 }
2116 else
2117 {
2118 org_a = next->org_u;
2119 cur_a = next->cur_u;
2120 org_ab = first->org_u - org_a;
2121 cur_ab = first->cur_u - cur_a;
2122 }
2123
2124 scale_ab = 0x10000L;
2125 if ( org_ab > 0 )
2126 scale_ab = FT_DivFix( cur_ab, org_ab );
2127
2128 point = first->next;
2129 do
2130 {
2131 org_c = point->org_u;
2132 org_ac = org_c - org_a;
2133
2134 if ( org_ac <= 0 )
2135 {
2136 /* on the left of the interpolation zone */
2137 cur_c = cur_a + FT_MulFix( org_ac, scale );
2138 }
2139 else if ( org_ac >= org_ab )
2140 {
2141 /* on the right on the interpolation zone */
2142 cur_c = cur_a + cur_ab + FT_MulFix( org_ac - org_ab, scale );
2143 }
2144 else
2145 {
2146 /* within the interpolation zone */
2147 cur_c = cur_a + FT_MulFix( org_ac, scale_ab );
2148 }
2149
2150 point->cur_u = cur_c;
2151
2152 point = point->next;
2153
2154 } while ( point != next );
2155 }
2156
2157 /* keep going until all points in the contours have been processed */
2158 first = next;
2159
2160 } while ( first != start );
2161
2162 Next_Contour:
2163 ;
2164 }
2165 }
2166
2167
2168 /*************************************************************************/
2169 /*************************************************************************/
2170 /***** *****/
2171 /***** HIGH-LEVEL INTERFACE *****/
2172 /***** *****/
2173 /*************************************************************************/
2174 /*************************************************************************/
2175
2176 FT_Error
2177 ps_hints_apply( PS_Hints ps_hints,
2178 FT_Outline* outline,
2179 PSH_Globals globals,
2180 FT_Render_Mode hint_mode )
2181 {
2182 PSH_GlyphRec glyphrec;
2183 PSH_Glyph glyph = &glyphrec;
2184 FT_Error error;
2185 #ifdef DEBUG_HINTER
2186 FT_Memory memory;
2187 #endif
2188 FT_Int dimension;
2189
2190
2191 /* something to do? */
2192 if ( outline->n_points == 0 || outline->n_contours == 0 )
2193 return PSH_Err_Ok;
2194
2195 #ifdef DEBUG_HINTER
2196
2197 memory = globals->memory;
2198
2199 if ( ps_debug_glyph )
2200 {
2201 psh_glyph_done( ps_debug_glyph );
2202 FT_FREE( ps_debug_glyph );
2203 }
2204
2205 if ( FT_NEW( glyph ) )
2206 return error;
2207
2208 ps_debug_glyph = glyph;
2209
2210 #endif /* DEBUG_HINTER */
2211
2212 error = psh_glyph_init( glyph, outline, ps_hints, globals );
2213 if ( error )
2214 goto Exit;
2215
2216 /* try to optimize the y_scale so that the top of non-capital letters
2217 * is aligned on a pixel boundary whenever possible
2218 */
2219 {
2220 PSH_Dimension dim_x = &glyph->globals->dimension[0];
2221 PSH_Dimension dim_y = &glyph->globals->dimension[1];
2222
2223 FT_Fixed x_scale = dim_x->scale_mult;
2224 FT_Fixed y_scale = dim_y->scale_mult;
2225
2226 FT_Fixed old_x_scale = x_scale;
2227 FT_Fixed old_y_scale = y_scale;
2228
2229 FT_Fixed scaled;
2230 FT_Fixed fitted;
2231
2232 FT_Bool rescale = FALSE;
2233
2234
2235 scaled = FT_MulFix( globals->blues.normal_top.zones->org_ref, y_scale );
2236 fitted = FT_PIX_ROUND( scaled );
2237
2238 if ( fitted != 0 && scaled != fitted )
2239 {
2240 rescale = TRUE;
2241
2242 y_scale = FT_MulDiv( y_scale, fitted, scaled );
2243
2244 if ( fitted < scaled )
2245 x_scale -= x_scale / 50;
2246
2247 psh_globals_set_scale( glyph->globals, x_scale, y_scale, 0, 0 );
2248 }
2249
2250 glyph->do_horz_hints = 1;
2251 glyph->do_vert_hints = 1;
2252
2253 glyph->do_horz_snapping = FT_BOOL( hint_mode == FT_RENDER_MODE_MONO ||
2254 hint_mode == FT_RENDER_MODE_LCD );
2255
2256 glyph->do_vert_snapping = FT_BOOL( hint_mode == FT_RENDER_MODE_MONO ||
2257 hint_mode == FT_RENDER_MODE_LCD_V );
2258
2259 glyph->do_stem_adjust = FT_BOOL( hint_mode != FT_RENDER_MODE_LIGHT );
2260
2261 for ( dimension = 0; dimension < 2; dimension++ )
2262 {
2263 /* load outline coordinates into glyph */
2264 psh_glyph_load_points( glyph, dimension );
2265
2266 /* compute local extrema */
2267 psh_glyph_compute_extrema( glyph );
2268
2269 /* compute aligned stem/hints positions */
2270 psh_hint_table_align_hints( &glyph->hint_tables[dimension],
2271 glyph->globals,
2272 dimension,
2273 glyph );
2274
2275 /* find strong points, align them, then interpolate others */
2276 psh_glyph_find_strong_points( glyph, dimension );
2277 if ( dimension == 1 )
2278 psh_glyph_find_blue_points( &globals->blues, glyph );
2279 psh_glyph_interpolate_strong_points( glyph, dimension );
2280 psh_glyph_interpolate_normal_points( glyph, dimension );
2281 psh_glyph_interpolate_other_points( glyph, dimension );
2282
2283 /* save hinted coordinates back to outline */
2284 psh_glyph_save_points( glyph, dimension );
2285
2286 if ( rescale )
2287 psh_globals_set_scale( glyph->globals,
2288 old_x_scale, old_y_scale, 0, 0 );
2289 }
2290 }
2291
2292 Exit:
2293
2294 #ifndef DEBUG_HINTER
2295 psh_glyph_done( glyph );
2296 #endif
2297
2298 return error;
2299 }
2300
2301
2302 /* END */
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