xref: /aosp_15_r20/external/freetype/src/base/ftoutln.c (revision 63949dbd25bcc50c4e1178497ff9e9574d44fc5a)
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 )
FT_Outline_Decompose(FT_Outline * outline,const FT_Outline_Funcs * func_interface,void * user)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 )
FT_Outline_New(FT_Library library,FT_UInt numPoints,FT_Int numContours,FT_Outline * anoutline)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 )
FT_Outline_Check(FT_Outline * outline)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 )
FT_Outline_Copy(const FT_Outline * source,FT_Outline * target)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 )
FT_Outline_Done(FT_Library library,FT_Outline * outline)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 )
FT_Outline_Get_CBox(const FT_Outline * outline,FT_BBox * acbox)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 )
FT_Outline_Translate(const FT_Outline * outline,FT_Pos xOffset,FT_Pos yOffset)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 )
FT_Outline_Reverse(FT_Outline * outline)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 )
FT_Outline_Render(FT_Library library,FT_Outline * outline,FT_Raster_Params * params)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 )
FT_Outline_Get_Bitmap(FT_Library library,FT_Outline * outline,const FT_Bitmap * abitmap)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, &params );
688   }
689 
690 
691   /* documentation is in freetype.h */
692 
693   FT_EXPORT_DEF( void )
FT_Vector_Transform(FT_Vector * vector,const FT_Matrix * matrix)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 )
FT_Outline_Transform(const FT_Outline * outline,const FT_Matrix * matrix)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 )
FT_Outline_Embolden(FT_Outline * outline,FT_Pos strength)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 )
FT_Outline_EmboldenXY(FT_Outline * outline,FT_Pos xstrength,FT_Pos ystrength)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 )
FT_Outline_Get_Orientation(FT_Outline * outline)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 */
1119