1 /****************************************************************************
2 *
3 * ftoutln.c
4 *
5 * FreeType outline management (body).
6 *
7 * Copyright (C) 1996-2023 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 <freetype/ftoutln.h>
20 #include <freetype/internal/ftobjs.h>
21 #include <freetype/internal/ftcalc.h>
22 #include <freetype/internal/ftdebug.h>
23 #include <freetype/fttrigon.h>
24
25
26 /**************************************************************************
27 *
28 * The macro FT_COMPONENT is used in trace mode. It is an implicit
29 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log
30 * messages during execution.
31 */
32 #undef FT_COMPONENT
33 #define FT_COMPONENT outline
34
35
36 static
37 const FT_Outline null_outline = { 0, 0, NULL, NULL, NULL, 0 };
38
39
40 /* documentation is in ftoutln.h */
41
42 FT_EXPORT_DEF( FT_Error )
43 FT_Outline_Decompose( FT_Outline* outline,
44 const FT_Outline_Funcs* func_interface,
45 void* user )
46 {
47 #undef SCALED
48 #define SCALED( x ) ( (x) * ( 1L << shift ) - delta )
49
50 FT_Vector v_last;
51 FT_Vector v_control;
52 FT_Vector v_start;
53
54 FT_Vector* point;
55 FT_Vector* limit;
56 char* tags;
57
58 FT_Error error;
59
60 FT_Int n; /* index of contour in outline */
61 FT_Int first; /* index of first point in contour */
62 FT_Int last; /* index of last point in contour */
63
64 FT_Int tag; /* current point's state */
65
66 FT_Int shift;
67 FT_Pos delta;
68
69
70 if ( !outline )
71 return FT_THROW( Invalid_Outline );
72
73 if ( !func_interface )
74 return FT_THROW( Invalid_Argument );
75
76 shift = func_interface->shift;
77 delta = func_interface->delta;
78
79 last = -1;
80 for ( n = 0; n < outline->n_contours; n++ )
81 {
82 FT_TRACE5(( "FT_Outline_Decompose: Contour %d\n", n ));
83
84 first = last + 1;
85 last = outline->contours[n];
86 if ( last < first )
87 goto Invalid_Outline;
88
89 limit = outline->points + last;
90
91 v_start = outline->points[first];
92 v_start.x = SCALED( v_start.x );
93 v_start.y = SCALED( v_start.y );
94
95 v_last = outline->points[last];
96 v_last.x = SCALED( v_last.x );
97 v_last.y = SCALED( v_last.y );
98
99 v_control = v_start;
100
101 point = outline->points + first;
102 tags = outline->tags + first;
103 tag = FT_CURVE_TAG( tags[0] );
104
105 /* A contour cannot start with a cubic control point! */
106 if ( tag == FT_CURVE_TAG_CUBIC )
107 goto Invalid_Outline;
108
109 /* check first point to determine origin */
110 if ( tag == FT_CURVE_TAG_CONIC )
111 {
112 /* first point is conic control. Yes, this happens. */
113 if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON )
114 {
115 /* start at last point if it is on the curve */
116 v_start = v_last;
117 limit--;
118 }
119 else
120 {
121 /* if both first and last points are conic, */
122 /* start at their middle and record its position */
123 /* for closure */
124 v_start.x = ( v_start.x + v_last.x ) / 2;
125 v_start.y = ( v_start.y + v_last.y ) / 2;
126
127 /* v_last = v_start; */
128 }
129 point--;
130 tags--;
131 }
132
133 FT_TRACE5(( " move to (%.2f, %.2f)\n",
134 (double)v_start.x / 64, (double)v_start.y / 64 ));
135 error = func_interface->move_to( &v_start, user );
136 if ( error )
137 goto Exit;
138
139 while ( point < limit )
140 {
141 point++;
142 tags++;
143
144 tag = FT_CURVE_TAG( tags[0] );
145 switch ( tag )
146 {
147 case FT_CURVE_TAG_ON: /* emit a single line_to */
148 {
149 FT_Vector vec;
150
151
152 vec.x = SCALED( point->x );
153 vec.y = SCALED( point->y );
154
155 FT_TRACE5(( " line to (%.2f, %.2f)\n",
156 (double)vec.x / 64, (double)vec.y / 64 ));
157 error = func_interface->line_to( &vec, user );
158 if ( error )
159 goto Exit;
160 continue;
161 }
162
163 case FT_CURVE_TAG_CONIC: /* consume conic arcs */
164 v_control.x = SCALED( point->x );
165 v_control.y = SCALED( point->y );
166
167 Do_Conic:
168 if ( point < limit )
169 {
170 FT_Vector vec;
171 FT_Vector v_middle;
172
173
174 point++;
175 tags++;
176 tag = FT_CURVE_TAG( tags[0] );
177
178 vec.x = SCALED( point->x );
179 vec.y = SCALED( point->y );
180
181 if ( tag == FT_CURVE_TAG_ON )
182 {
183 FT_TRACE5(( " conic to (%.2f, %.2f)"
184 " with control (%.2f, %.2f)\n",
185 (double)vec.x / 64,
186 (double)vec.y / 64,
187 (double)v_control.x / 64,
188 (double)v_control.y / 64 ));
189 error = func_interface->conic_to( &v_control, &vec, user );
190 if ( error )
191 goto Exit;
192 continue;
193 }
194
195 if ( tag != FT_CURVE_TAG_CONIC )
196 goto Invalid_Outline;
197
198 v_middle.x = ( v_control.x + vec.x ) / 2;
199 v_middle.y = ( v_control.y + vec.y ) / 2;
200
201 FT_TRACE5(( " conic to (%.2f, %.2f)"
202 " with control (%.2f, %.2f)\n",
203 (double)v_middle.x / 64,
204 (double)v_middle.y / 64,
205 (double)v_control.x / 64,
206 (double)v_control.y / 64 ));
207 error = func_interface->conic_to( &v_control, &v_middle, user );
208 if ( error )
209 goto Exit;
210
211 v_control = vec;
212 goto Do_Conic;
213 }
214
215 FT_TRACE5(( " conic to (%.2f, %.2f)"
216 " with control (%.2f, %.2f)\n",
217 (double)v_start.x / 64,
218 (double)v_start.y / 64,
219 (double)v_control.x / 64,
220 (double)v_control.y / 64 ));
221 error = func_interface->conic_to( &v_control, &v_start, user );
222 goto Close;
223
224 default: /* FT_CURVE_TAG_CUBIC */
225 {
226 FT_Vector vec1, vec2;
227
228
229 if ( point + 1 > limit ||
230 FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC )
231 goto Invalid_Outline;
232
233 point += 2;
234 tags += 2;
235
236 vec1.x = SCALED( point[-2].x );
237 vec1.y = SCALED( point[-2].y );
238
239 vec2.x = SCALED( point[-1].x );
240 vec2.y = SCALED( point[-1].y );
241
242 if ( point <= limit )
243 {
244 FT_Vector vec;
245
246
247 vec.x = SCALED( point->x );
248 vec.y = SCALED( point->y );
249
250 FT_TRACE5(( " cubic to (%.2f, %.2f)"
251 " with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
252 (double)vec.x / 64,
253 (double)vec.y / 64,
254 (double)vec1.x / 64,
255 (double)vec1.y / 64,
256 (double)vec2.x / 64,
257 (double)vec2.y / 64 ));
258 error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
259 if ( error )
260 goto Exit;
261 continue;
262 }
263
264 FT_TRACE5(( " cubic to (%.2f, %.2f)"
265 " with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
266 (double)v_start.x / 64,
267 (double)v_start.y / 64,
268 (double)vec1.x / 64,
269 (double)vec1.y / 64,
270 (double)vec2.x / 64,
271 (double)vec2.y / 64 ));
272 error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
273 goto Close;
274 }
275 }
276 }
277
278 /* close the contour with a line segment */
279 FT_TRACE5(( " line to (%.2f, %.2f)\n",
280 (double)v_start.x / 64, (double)v_start.y / 64 ));
281 error = func_interface->line_to( &v_start, user );
282
283 Close:
284 if ( error )
285 goto Exit;
286 }
287
288 FT_TRACE5(( "FT_Outline_Decompose: Done\n" ));
289 return FT_Err_Ok;
290
291 Invalid_Outline:
292 error = FT_THROW( Invalid_Outline );
293 /* fall through */
294
295 Exit:
296 FT_TRACE5(( "FT_Outline_Decompose: Error 0x%x\n", error ));
297 return error;
298 }
299
300
301 /* documentation is in ftoutln.h */
302
303 FT_EXPORT_DEF( FT_Error )
304 FT_Outline_New( FT_Library library,
305 FT_UInt numPoints,
306 FT_Int numContours,
307 FT_Outline *anoutline )
308 {
309 FT_Error error;
310 FT_Memory memory;
311
312
313 if ( !library )
314 return FT_THROW( Invalid_Library_Handle );
315
316 memory = library->memory;
317
318 if ( !anoutline || !memory )
319 return FT_THROW( Invalid_Argument );
320
321 *anoutline = null_outline;
322
323 if ( numContours < 0 ||
324 (FT_UInt)numContours > numPoints )
325 return FT_THROW( Invalid_Argument );
326
327 if ( numPoints > FT_OUTLINE_POINTS_MAX )
328 return FT_THROW( Array_Too_Large );
329
330 if ( FT_NEW_ARRAY( anoutline->points, numPoints ) ||
331 FT_NEW_ARRAY( anoutline->tags, numPoints ) ||
332 FT_NEW_ARRAY( anoutline->contours, numContours ) )
333 goto Fail;
334
335 anoutline->n_points = (FT_Short)numPoints;
336 anoutline->n_contours = (FT_Short)numContours;
337 anoutline->flags |= FT_OUTLINE_OWNER;
338
339 return FT_Err_Ok;
340
341 Fail:
342 anoutline->flags |= FT_OUTLINE_OWNER;
343 FT_Outline_Done( library, anoutline );
344
345 return error;
346 }
347
348
349 /* documentation is in ftoutln.h */
350
351 FT_EXPORT_DEF( FT_Error )
352 FT_Outline_Check( FT_Outline* outline )
353 {
354 if ( outline )
355 {
356 FT_Int n_points = outline->n_points;
357 FT_Int n_contours = outline->n_contours;
358 FT_Int end0, end;
359 FT_Int n;
360
361
362 /* empty glyph? */
363 if ( n_points == 0 && n_contours == 0 )
364 return FT_Err_Ok;
365
366 /* check point and contour counts */
367 if ( n_points <= 0 || n_contours <= 0 )
368 goto Bad;
369
370 end0 = -1;
371 for ( n = 0; n < n_contours; n++ )
372 {
373 end = outline->contours[n];
374
375 /* note that we don't accept empty contours */
376 if ( end <= end0 || end >= n_points )
377 goto Bad;
378
379 end0 = end;
380 }
381
382 if ( end0 != n_points - 1 )
383 goto Bad;
384
385 /* XXX: check the tags array */
386 return FT_Err_Ok;
387 }
388
389 Bad:
390 return FT_THROW( Invalid_Outline );
391 }
392
393
394 /* documentation is in ftoutln.h */
395
396 FT_EXPORT_DEF( FT_Error )
397 FT_Outline_Copy( const FT_Outline* source,
398 FT_Outline *target )
399 {
400 FT_Int is_owner;
401
402
403 if ( !source || !target )
404 return FT_THROW( Invalid_Outline );
405
406 if ( source->n_points != target->n_points ||
407 source->n_contours != target->n_contours )
408 return FT_THROW( Invalid_Argument );
409
410 if ( source == target )
411 return FT_Err_Ok;
412
413 if ( source->n_points )
414 {
415 FT_ARRAY_COPY( target->points, source->points, source->n_points );
416 FT_ARRAY_COPY( target->tags, source->tags, source->n_points );
417 }
418
419 if ( source->n_contours )
420 FT_ARRAY_COPY( target->contours, source->contours, source->n_contours );
421
422 /* copy all flags, except the `FT_OUTLINE_OWNER' one */
423 is_owner = target->flags & FT_OUTLINE_OWNER;
424 target->flags = source->flags;
425
426 target->flags &= ~FT_OUTLINE_OWNER;
427 target->flags |= is_owner;
428
429 return FT_Err_Ok;
430 }
431
432
433 /* documentation is in ftoutln.h */
434
435 FT_EXPORT_DEF( FT_Error )
436 FT_Outline_Done( FT_Library library,
437 FT_Outline* outline )
438 {
439 FT_Memory memory;
440
441
442 if ( !library )
443 return FT_THROW( Invalid_Library_Handle );
444
445 if ( !outline )
446 return FT_THROW( Invalid_Outline );
447
448 memory = library->memory;
449
450 if ( !memory )
451 return FT_THROW( Invalid_Argument );
452
453 if ( outline->flags & FT_OUTLINE_OWNER )
454 {
455 FT_FREE( outline->points );
456 FT_FREE( outline->tags );
457 FT_FREE( outline->contours );
458 }
459 *outline = null_outline;
460
461 return FT_Err_Ok;
462 }
463
464
465 /* documentation is in ftoutln.h */
466
467 FT_EXPORT_DEF( void )
468 FT_Outline_Get_CBox( const FT_Outline* outline,
469 FT_BBox *acbox )
470 {
471 FT_Pos xMin, yMin, xMax, yMax;
472
473
474 if ( outline && acbox )
475 {
476 if ( outline->n_points == 0 )
477 {
478 xMin = 0;
479 yMin = 0;
480 xMax = 0;
481 yMax = 0;
482 }
483 else
484 {
485 FT_Vector* vec = outline->points;
486 FT_Vector* limit = vec + outline->n_points;
487
488
489 xMin = xMax = vec->x;
490 yMin = yMax = vec->y;
491 vec++;
492
493 for ( ; vec < limit; vec++ )
494 {
495 FT_Pos x, y;
496
497
498 x = vec->x;
499 if ( x < xMin ) xMin = x;
500 if ( x > xMax ) xMax = x;
501
502 y = vec->y;
503 if ( y < yMin ) yMin = y;
504 if ( y > yMax ) yMax = y;
505 }
506 }
507 acbox->xMin = xMin;
508 acbox->xMax = xMax;
509 acbox->yMin = yMin;
510 acbox->yMax = yMax;
511 }
512 }
513
514
515 /* documentation is in ftoutln.h */
516
517 FT_EXPORT_DEF( void )
518 FT_Outline_Translate( const FT_Outline* outline,
519 FT_Pos xOffset,
520 FT_Pos yOffset )
521 {
522 FT_UShort n;
523 FT_Vector* vec;
524
525
526 if ( !outline )
527 return;
528
529 vec = outline->points;
530
531 for ( n = 0; n < outline->n_points; n++ )
532 {
533 vec->x = ADD_LONG( vec->x, xOffset );
534 vec->y = ADD_LONG( vec->y, yOffset );
535 vec++;
536 }
537 }
538
539
540 /* documentation is in ftoutln.h */
541
542 FT_EXPORT_DEF( void )
543 FT_Outline_Reverse( FT_Outline* outline )
544 {
545 FT_UShort n;
546 FT_Int first, last;
547
548
549 if ( !outline )
550 return;
551
552 last = -1;
553 for ( n = 0; n < outline->n_contours; n++ )
554 {
555 /* keep the first contour point as is and swap points around it */
556 /* to guarantee that the cubic arches stay valid after reverse */
557 first = last + 2;
558 last = outline->contours[n];
559
560 /* reverse point table */
561 {
562 FT_Vector* p = outline->points + first;
563 FT_Vector* q = outline->points + last;
564 FT_Vector swap;
565
566
567 while ( p < q )
568 {
569 swap = *p;
570 *p = *q;
571 *q = swap;
572 p++;
573 q--;
574 }
575 }
576
577 /* reverse tags table */
578 {
579 char* p = outline->tags + first;
580 char* q = outline->tags + last;
581
582
583 while ( p < q )
584 {
585 char swap;
586
587
588 swap = *p;
589 *p = *q;
590 *q = swap;
591 p++;
592 q--;
593 }
594 }
595 }
596
597 outline->flags ^= FT_OUTLINE_REVERSE_FILL;
598 }
599
600
601 /* documentation is in ftoutln.h */
602
603 FT_EXPORT_DEF( FT_Error )
604 FT_Outline_Render( FT_Library library,
605 FT_Outline* outline,
606 FT_Raster_Params* params )
607 {
608 FT_Error error;
609 FT_Renderer renderer;
610 FT_ListNode node;
611 FT_BBox cbox;
612
613
614 if ( !library )
615 return FT_THROW( Invalid_Library_Handle );
616
617 if ( !outline )
618 return FT_THROW( Invalid_Outline );
619
620 if ( !params )
621 return FT_THROW( Invalid_Argument );
622
623 FT_Outline_Get_CBox( outline, &cbox );
624 if ( cbox.xMin < -0x1000000L || cbox.yMin < -0x1000000L ||
625 cbox.xMax > 0x1000000L || cbox.yMax > 0x1000000L )
626 return FT_THROW( Invalid_Outline );
627
628 renderer = library->cur_renderer;
629 node = library->renderers.head;
630
631 params->source = (void*)outline;
632
633 /* preset clip_box for direct mode */
634 if ( params->flags & FT_RASTER_FLAG_DIRECT &&
635 !( params->flags & FT_RASTER_FLAG_CLIP ) )
636 {
637 params->clip_box.xMin = cbox.xMin >> 6;
638 params->clip_box.yMin = cbox.yMin >> 6;
639 params->clip_box.xMax = ( cbox.xMax + 63 ) >> 6;
640 params->clip_box.yMax = ( cbox.yMax + 63 ) >> 6;
641 }
642
643 error = FT_ERR( Cannot_Render_Glyph );
644 while ( renderer )
645 {
646 error = renderer->raster_render( renderer->raster, params );
647 if ( !error || FT_ERR_NEQ( error, Cannot_Render_Glyph ) )
648 break;
649
650 /* FT_Err_Cannot_Render_Glyph is returned if the render mode */
651 /* is unsupported by the current renderer for this glyph image */
652 /* format */
653
654 /* now, look for another renderer that supports the same */
655 /* format */
656 renderer = FT_Lookup_Renderer( library, FT_GLYPH_FORMAT_OUTLINE,
657 &node );
658 }
659
660 return error;
661 }
662
663
664 /* documentation is in ftoutln.h */
665
666 FT_EXPORT_DEF( FT_Error )
667 FT_Outline_Get_Bitmap( FT_Library library,
668 FT_Outline* outline,
669 const FT_Bitmap *abitmap )
670 {
671 FT_Raster_Params params;
672
673
674 if ( !abitmap )
675 return FT_THROW( Invalid_Argument );
676
677 /* other checks are delayed to `FT_Outline_Render' */
678
679 params.target = abitmap;
680 params.flags = 0;
681
682 if ( abitmap->pixel_mode == FT_PIXEL_MODE_GRAY ||
683 abitmap->pixel_mode == FT_PIXEL_MODE_LCD ||
684 abitmap->pixel_mode == FT_PIXEL_MODE_LCD_V )
685 params.flags |= FT_RASTER_FLAG_AA;
686
687 return FT_Outline_Render( library, outline, ¶ms );
688 }
689
690
691 /* documentation is in freetype.h */
692
693 FT_EXPORT_DEF( void )
694 FT_Vector_Transform( FT_Vector* vector,
695 const FT_Matrix* matrix )
696 {
697 FT_Pos xz, yz;
698
699
700 if ( !vector || !matrix )
701 return;
702
703 xz = FT_MulFix( vector->x, matrix->xx ) +
704 FT_MulFix( vector->y, matrix->xy );
705
706 yz = FT_MulFix( vector->x, matrix->yx ) +
707 FT_MulFix( vector->y, matrix->yy );
708
709 vector->x = xz;
710 vector->y = yz;
711 }
712
713
714 /* documentation is in ftoutln.h */
715
716 FT_EXPORT_DEF( void )
717 FT_Outline_Transform( const FT_Outline* outline,
718 const FT_Matrix* matrix )
719 {
720 FT_Vector* vec;
721 FT_Vector* limit;
722
723
724 if ( !outline || !matrix || !outline->points )
725 return;
726
727 vec = outline->points;
728 limit = vec + outline->n_points;
729
730 for ( ; vec < limit; vec++ )
731 FT_Vector_Transform( vec, matrix );
732 }
733
734
735 #if 0
736
737 #define FT_OUTLINE_GET_CONTOUR( outline, c, first, last ) \
738 do \
739 { \
740 (first) = ( c > 0 ) ? (outline)->points + \
741 (outline)->contours[c - 1] + 1 \
742 : (outline)->points; \
743 (last) = (outline)->points + (outline)->contours[c]; \
744 } while ( 0 )
745
746
747 /* Is a point in some contour? */
748 /* */
749 /* We treat every point of the contour as if it */
750 /* it were ON. That is, we allow false positives, */
751 /* but disallow false negatives. (XXX really?) */
752 static FT_Bool
753 ft_contour_has( FT_Outline* outline,
754 FT_Short c,
755 FT_Vector* point )
756 {
757 FT_Vector* first;
758 FT_Vector* last;
759 FT_Vector* a;
760 FT_Vector* b;
761 FT_UInt n = 0;
762
763
764 FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
765
766 for ( a = first; a <= last; a++ )
767 {
768 FT_Pos x;
769 FT_Int intersect;
770
771
772 b = ( a == last ) ? first : a + 1;
773
774 intersect = ( a->y - point->y ) ^ ( b->y - point->y );
775
776 /* a and b are on the same side */
777 if ( intersect >= 0 )
778 {
779 if ( intersect == 0 && a->y == point->y )
780 {
781 if ( ( a->x <= point->x && b->x >= point->x ) ||
782 ( a->x >= point->x && b->x <= point->x ) )
783 return 1;
784 }
785
786 continue;
787 }
788
789 x = a->x + ( b->x - a->x ) * (point->y - a->y ) / ( b->y - a->y );
790
791 if ( x < point->x )
792 n++;
793 else if ( x == point->x )
794 return 1;
795 }
796
797 return n & 1;
798 }
799
800
801 static FT_Bool
802 ft_contour_enclosed( FT_Outline* outline,
803 FT_UShort c )
804 {
805 FT_Vector* first;
806 FT_Vector* last;
807 FT_Short i;
808
809
810 FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
811
812 for ( i = 0; i < outline->n_contours; i++ )
813 {
814 if ( i != c && ft_contour_has( outline, i, first ) )
815 {
816 FT_Vector* pt;
817
818
819 for ( pt = first + 1; pt <= last; pt++ )
820 if ( !ft_contour_has( outline, i, pt ) )
821 return 0;
822
823 return 1;
824 }
825 }
826
827 return 0;
828 }
829
830
831 /* This version differs from the public one in that each */
832 /* part (contour not enclosed in another contour) of the */
833 /* outline is checked for orientation. This is */
834 /* necessary for some buggy CJK fonts. */
835 static FT_Orientation
836 ft_outline_get_orientation( FT_Outline* outline )
837 {
838 FT_Short i;
839 FT_Vector* first;
840 FT_Vector* last;
841 FT_Orientation orient = FT_ORIENTATION_NONE;
842
843
844 first = outline->points;
845 for ( i = 0; i < outline->n_contours; i++, first = last + 1 )
846 {
847 FT_Vector* point;
848 FT_Vector* xmin_point;
849 FT_Pos xmin;
850
851
852 last = outline->points + outline->contours[i];
853
854 /* skip degenerate contours */
855 if ( last < first + 2 )
856 continue;
857
858 if ( ft_contour_enclosed( outline, i ) )
859 continue;
860
861 xmin = first->x;
862 xmin_point = first;
863
864 for ( point = first + 1; point <= last; point++ )
865 {
866 if ( point->x < xmin )
867 {
868 xmin = point->x;
869 xmin_point = point;
870 }
871 }
872
873 /* check the orientation of the contour */
874 {
875 FT_Vector* prev;
876 FT_Vector* next;
877 FT_Orientation o;
878
879
880 prev = ( xmin_point == first ) ? last : xmin_point - 1;
881 next = ( xmin_point == last ) ? first : xmin_point + 1;
882
883 if ( FT_Atan2( prev->x - xmin_point->x, prev->y - xmin_point->y ) >
884 FT_Atan2( next->x - xmin_point->x, next->y - xmin_point->y ) )
885 o = FT_ORIENTATION_POSTSCRIPT;
886 else
887 o = FT_ORIENTATION_TRUETYPE;
888
889 if ( orient == FT_ORIENTATION_NONE )
890 orient = o;
891 else if ( orient != o )
892 return FT_ORIENTATION_NONE;
893 }
894 }
895
896 return orient;
897 }
898
899 #endif /* 0 */
900
901
902 /* documentation is in ftoutln.h */
903
904 FT_EXPORT_DEF( FT_Error )
905 FT_Outline_Embolden( FT_Outline* outline,
906 FT_Pos strength )
907 {
908 return FT_Outline_EmboldenXY( outline, strength, strength );
909 }
910
911
912 /* documentation is in ftoutln.h */
913
914 FT_EXPORT_DEF( FT_Error )
915 FT_Outline_EmboldenXY( FT_Outline* outline,
916 FT_Pos xstrength,
917 FT_Pos ystrength )
918 {
919 FT_Vector* points;
920 FT_Int c, first, last;
921 FT_Orientation orientation;
922
923
924 if ( !outline )
925 return FT_THROW( Invalid_Outline );
926
927 xstrength /= 2;
928 ystrength /= 2;
929 if ( xstrength == 0 && ystrength == 0 )
930 return FT_Err_Ok;
931
932 orientation = FT_Outline_Get_Orientation( outline );
933 if ( orientation == FT_ORIENTATION_NONE )
934 {
935 if ( outline->n_contours )
936 return FT_THROW( Invalid_Argument );
937 else
938 return FT_Err_Ok;
939 }
940
941 points = outline->points;
942
943 last = -1;
944 for ( c = 0; c < outline->n_contours; c++ )
945 {
946 FT_Vector in, out, anchor, shift;
947 FT_Fixed l_in, l_out, l_anchor = 0, l, q, d;
948 FT_Int i, j, k;
949
950
951 first = last + 1;
952 last = outline->contours[c];
953 l_in = 0;
954
955 /* pacify compiler */
956 in.x = in.y = anchor.x = anchor.y = 0;
957
958 /* Counter j cycles though the points; counter i advances only */
959 /* when points are moved; anchor k marks the first moved point. */
960 for ( i = last, j = first, k = -1;
961 j != i && i != k;
962 j = j < last ? j + 1 : first )
963 {
964 if ( j != k )
965 {
966 out.x = points[j].x - points[i].x;
967 out.y = points[j].y - points[i].y;
968 l_out = (FT_Fixed)FT_Vector_NormLen( &out );
969
970 if ( l_out == 0 )
971 continue;
972 }
973 else
974 {
975 out = anchor;
976 l_out = l_anchor;
977 }
978
979 if ( l_in != 0 )
980 {
981 if ( k < 0 )
982 {
983 k = i;
984 anchor = in;
985 l_anchor = l_in;
986 }
987
988 d = FT_MulFix( in.x, out.x ) + FT_MulFix( in.y, out.y );
989
990 /* shift only if turn is less than ~160 degrees */
991 if ( d > -0xF000L )
992 {
993 d = d + 0x10000L;
994
995 /* shift components along lateral bisector in proper orientation */
996 shift.x = in.y + out.y;
997 shift.y = in.x + out.x;
998
999 if ( orientation == FT_ORIENTATION_TRUETYPE )
1000 shift.x = -shift.x;
1001 else
1002 shift.y = -shift.y;
1003
1004 /* restrict shift magnitude to better handle collapsing segments */
1005 q = FT_MulFix( out.x, in.y ) - FT_MulFix( out.y, in.x );
1006 if ( orientation == FT_ORIENTATION_TRUETYPE )
1007 q = -q;
1008
1009 l = FT_MIN( l_in, l_out );
1010
1011 /* non-strict inequalities avoid divide-by-zero when q == l == 0 */
1012 if ( FT_MulFix( xstrength, q ) <= FT_MulFix( l, d ) )
1013 shift.x = FT_MulDiv( shift.x, xstrength, d );
1014 else
1015 shift.x = FT_MulDiv( shift.x, l, q );
1016
1017
1018 if ( FT_MulFix( ystrength, q ) <= FT_MulFix( l, d ) )
1019 shift.y = FT_MulDiv( shift.y, ystrength, d );
1020 else
1021 shift.y = FT_MulDiv( shift.y, l, q );
1022 }
1023 else
1024 shift.x = shift.y = 0;
1025
1026 for ( ;
1027 i != j;
1028 i = i < last ? i + 1 : first )
1029 {
1030 points[i].x += xstrength + shift.x;
1031 points[i].y += ystrength + shift.y;
1032 }
1033 }
1034 else
1035 i = j;
1036
1037 in = out;
1038 l_in = l_out;
1039 }
1040 }
1041
1042 return FT_Err_Ok;
1043 }
1044
1045
1046 /* documentation is in ftoutln.h */
1047
1048 FT_EXPORT_DEF( FT_Orientation )
1049 FT_Outline_Get_Orientation( FT_Outline* outline )
1050 {
1051 FT_BBox cbox = { 0, 0, 0, 0 };
1052 FT_Int xshift, yshift;
1053 FT_Vector* points;
1054 FT_Vector v_prev, v_cur;
1055 FT_Int c, n, first, last;
1056 FT_Pos area = 0;
1057
1058
1059 if ( !outline || outline->n_points <= 0 )
1060 return FT_ORIENTATION_TRUETYPE;
1061
1062 /* We use the nonzero winding rule to find the orientation. */
1063 /* Since glyph outlines behave much more `regular' than arbitrary */
1064 /* cubic or quadratic curves, this test deals with the polygon */
1065 /* only that is spanned up by the control points. */
1066
1067 FT_Outline_Get_CBox( outline, &cbox );
1068
1069 /* Handle collapsed outlines to avoid undefined FT_MSB. */
1070 if ( cbox.xMin == cbox.xMax || cbox.yMin == cbox.yMax )
1071 return FT_ORIENTATION_NONE;
1072
1073 /* Reject values large outlines. */
1074 if ( cbox.xMin < -0x1000000L || cbox.yMin < -0x1000000L ||
1075 cbox.xMax > 0x1000000L || cbox.yMax > 0x1000000L )
1076 return FT_ORIENTATION_NONE;
1077
1078 xshift = FT_MSB( (FT_UInt32)( FT_ABS( cbox.xMax ) |
1079 FT_ABS( cbox.xMin ) ) ) - 14;
1080 xshift = FT_MAX( xshift, 0 );
1081
1082 yshift = FT_MSB( (FT_UInt32)( cbox.yMax - cbox.yMin ) ) - 14;
1083 yshift = FT_MAX( yshift, 0 );
1084
1085 points = outline->points;
1086
1087 last = -1;
1088 for ( c = 0; c < outline->n_contours; c++ )
1089 {
1090 first = last + 1;
1091 last = outline->contours[c];
1092
1093 v_prev.x = points[last].x >> xshift;
1094 v_prev.y = points[last].y >> yshift;
1095
1096 for ( n = first; n <= last; n++ )
1097 {
1098 v_cur.x = points[n].x >> xshift;
1099 v_cur.y = points[n].y >> yshift;
1100
1101 area = ADD_LONG( area,
1102 MUL_LONG( v_cur.y - v_prev.y,
1103 v_cur.x + v_prev.x ) );
1104
1105 v_prev = v_cur;
1106 }
1107 }
1108
1109 if ( area > 0 )
1110 return FT_ORIENTATION_POSTSCRIPT;
1111 else if ( area < 0 )
1112 return FT_ORIENTATION_TRUETYPE;
1113 else
1114 return FT_ORIENTATION_NONE;
1115 }
1116
1117
1118 /* END */