1 /***************************************************************************/
2 /*                                                                         */
3 /*  ftoutln.c                                                              */
4 /*                                                                         */
5 /*    FreeType outline management (body).                                  */
6 /*                                                                         */
7 /*  Copyright 1996-2008, 2010, 2012-2013 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   /*************************************************************************/
20   /*                                                                       */
21   /* All functions are declared in freetype.h.                             */
22   /*                                                                       */
23   /*************************************************************************/
24 
25 
26 #include <ft2build.h>
27 #include FT_OUTLINE_H
28 #include FT_INTERNAL_OBJECTS_H
29 #include FT_INTERNAL_CALC_H
30 #include FT_INTERNAL_DEBUG_H
31 #include FT_TRIGONOMETRY_H
32 
33 
34   /*************************************************************************/
35   /*                                                                       */
36   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
37   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
38   /* messages during execution.                                            */
39   /*                                                                       */
40 #undef  FT_COMPONENT
41 #define FT_COMPONENT  trace_outline
42 
43 
44   static
45   const FT_Outline  null_outline = { 0, 0, 0, 0, 0, 0 };
46 
47 
48   /* documentation is in ftoutln.h */
49 
50   FT_EXPORT_DEF( FT_Error )
FT_Outline_Decompose(FT_Outline * outline,const FT_Outline_Funcs * func_interface,void * user)51   FT_Outline_Decompose( FT_Outline*              outline,
52                         const FT_Outline_Funcs*  func_interface,
53                         void*                    user )
54   {
55 #undef SCALED
56 #define SCALED( x )  ( ( (x) << shift ) - delta )
57 
58     FT_Vector   v_last;
59     FT_Vector   v_control;
60     FT_Vector   v_start;
61 
62     FT_Vector*  point;
63     FT_Vector*  limit;
64     char*       tags;
65 
66     FT_Error    error;
67 
68     FT_Int   n;         /* index of contour in outline     */
69     FT_UInt  first;     /* index of first point in contour */
70     FT_Int   tag;       /* current point's state           */
71 
72     FT_Int   shift;
73     FT_Pos   delta;
74 
75 
76     if ( !outline || !func_interface )
77       return FT_THROW( Invalid_Argument );
78 
79     shift = func_interface->shift;
80     delta = func_interface->delta;
81     first = 0;
82 
83     for ( n = 0; n < outline->n_contours; n++ )
84     {
85       FT_Int  last;  /* index of last point in contour */
86 
87 
88       FT_TRACE5(( "FT_Outline_Decompose: Outline %d\n", n ));
89 
90       last = outline->contours[n];
91       if ( last < 0 )
92         goto Invalid_Outline;
93       limit = outline->points + last;
94 
95       v_start   = outline->points[first];
96       v_start.x = SCALED( v_start.x );
97       v_start.y = SCALED( v_start.y );
98 
99       v_last   = outline->points[last];
100       v_last.x = SCALED( v_last.x );
101       v_last.y = SCALED( v_last.y );
102 
103       v_control = v_start;
104 
105       point = outline->points + first;
106       tags  = outline->tags   + first;
107       tag   = FT_CURVE_TAG( tags[0] );
108 
109       /* A contour cannot start with a cubic control point! */
110       if ( tag == FT_CURVE_TAG_CUBIC )
111         goto Invalid_Outline;
112 
113       /* check first point to determine origin */
114       if ( tag == FT_CURVE_TAG_CONIC )
115       {
116         /* first point is conic control.  Yes, this happens. */
117         if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON )
118         {
119           /* start at last point if it is on the curve */
120           v_start = v_last;
121           limit--;
122         }
123         else
124         {
125           /* if both first and last points are conic,         */
126           /* start at their middle and record its position    */
127           /* for closure                                      */
128           v_start.x = ( v_start.x + v_last.x ) / 2;
129           v_start.y = ( v_start.y + v_last.y ) / 2;
130 
131           v_last = v_start;
132         }
133         point--;
134         tags--;
135       }
136 
137       FT_TRACE5(( "  move to (%.2f, %.2f)\n",
138                   v_start.x / 64.0, v_start.y / 64.0 ));
139       error = func_interface->move_to( &v_start, user );
140       if ( error )
141         goto Exit;
142 
143       while ( point < limit )
144       {
145         point++;
146         tags++;
147 
148         tag = FT_CURVE_TAG( tags[0] );
149         switch ( tag )
150         {
151         case FT_CURVE_TAG_ON:  /* emit a single line_to */
152           {
153             FT_Vector  vec;
154 
155 
156             vec.x = SCALED( point->x );
157             vec.y = SCALED( point->y );
158 
159             FT_TRACE5(( "  line to (%.2f, %.2f)\n",
160                         vec.x / 64.0, vec.y / 64.0 ));
161             error = func_interface->line_to( &vec, user );
162             if ( error )
163               goto Exit;
164             continue;
165           }
166 
167         case FT_CURVE_TAG_CONIC:  /* consume conic arcs */
168           v_control.x = SCALED( point->x );
169           v_control.y = SCALED( point->y );
170 
171         Do_Conic:
172           if ( point < limit )
173           {
174             FT_Vector  vec;
175             FT_Vector  v_middle;
176 
177 
178             point++;
179             tags++;
180             tag = FT_CURVE_TAG( tags[0] );
181 
182             vec.x = SCALED( point->x );
183             vec.y = SCALED( point->y );
184 
185             if ( tag == FT_CURVE_TAG_ON )
186             {
187               FT_TRACE5(( "  conic to (%.2f, %.2f)"
188                           " with control (%.2f, %.2f)\n",
189                           vec.x / 64.0, vec.y / 64.0,
190                           v_control.x / 64.0, v_control.y / 64.0 ));
191               error = func_interface->conic_to( &v_control, &vec, user );
192               if ( error )
193                 goto Exit;
194               continue;
195             }
196 
197             if ( tag != FT_CURVE_TAG_CONIC )
198               goto Invalid_Outline;
199 
200             v_middle.x = ( v_control.x + vec.x ) / 2;
201             v_middle.y = ( v_control.y + vec.y ) / 2;
202 
203             FT_TRACE5(( "  conic to (%.2f, %.2f)"
204                         " with control (%.2f, %.2f)\n",
205                         v_middle.x / 64.0, v_middle.y / 64.0,
206                         v_control.x / 64.0, v_control.y / 64.0 ));
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                       v_start.x / 64.0, v_start.y / 64.0,
218                       v_control.x / 64.0, v_control.y / 64.0 ));
219           error = func_interface->conic_to( &v_control, &v_start, user );
220           goto Close;
221 
222         default:  /* FT_CURVE_TAG_CUBIC */
223           {
224             FT_Vector  vec1, vec2;
225 
226 
227             if ( point + 1 > limit                             ||
228                  FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC )
229               goto Invalid_Outline;
230 
231             point += 2;
232             tags  += 2;
233 
234             vec1.x = SCALED( point[-2].x );
235             vec1.y = SCALED( point[-2].y );
236 
237             vec2.x = SCALED( point[-1].x );
238             vec2.y = SCALED( point[-1].y );
239 
240             if ( point <= limit )
241             {
242               FT_Vector  vec;
243 
244 
245               vec.x = SCALED( point->x );
246               vec.y = SCALED( point->y );
247 
248               FT_TRACE5(( "  cubic to (%.2f, %.2f)"
249                           " with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
250                           vec.x / 64.0, vec.y / 64.0,
251                           vec1.x / 64.0, vec1.y / 64.0,
252                           vec2.x / 64.0, vec2.y / 64.0 ));
253               error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
254               if ( error )
255                 goto Exit;
256               continue;
257             }
258 
259             FT_TRACE5(( "  cubic to (%.2f, %.2f)"
260                         " with controls (%.2f, %.2f) and (%.2f, %.2f)\n",
261                         v_start.x / 64.0, v_start.y / 64.0,
262                         vec1.x / 64.0, vec1.y / 64.0,
263                         vec2.x / 64.0, vec2.y / 64.0 ));
264             error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
265             goto Close;
266           }
267         }
268       }
269 
270       /* close the contour with a line segment */
271       FT_TRACE5(( "  line to (%.2f, %.2f)\n",
272                   v_start.x / 64.0, v_start.y / 64.0 ));
273       error = func_interface->line_to( &v_start, user );
274 
275     Close:
276       if ( error )
277         goto Exit;
278 
279       first = last + 1;
280     }
281 
282     FT_TRACE5(( "FT_Outline_Decompose: Done\n", n ));
283     return FT_Err_Ok;
284 
285   Exit:
286     FT_TRACE5(( "FT_Outline_Decompose: Error %d\n", error ));
287     return error;
288 
289   Invalid_Outline:
290     return FT_THROW( Invalid_Outline );
291   }
292 
293 
294   FT_EXPORT_DEF( FT_Error )
FT_Outline_New_Internal(FT_Memory memory,FT_UInt numPoints,FT_Int numContours,FT_Outline * anoutline)295   FT_Outline_New_Internal( FT_Memory    memory,
296                            FT_UInt      numPoints,
297                            FT_Int       numContours,
298                            FT_Outline  *anoutline )
299   {
300     FT_Error  error;
301 
302 
303     if ( !anoutline || !memory )
304       return FT_THROW( Invalid_Argument );
305 
306     *anoutline = null_outline;
307 
308     if ( numContours < 0                  ||
309          (FT_UInt)numContours > numPoints )
310       return FT_THROW( Invalid_Argument );
311 
312     if ( numPoints > FT_OUTLINE_POINTS_MAX )
313       return FT_THROW( Array_Too_Large );
314 
315     if ( FT_NEW_ARRAY( anoutline->points,   numPoints   ) ||
316          FT_NEW_ARRAY( anoutline->tags,     numPoints   ) ||
317          FT_NEW_ARRAY( anoutline->contours, numContours ) )
318       goto Fail;
319 
320     anoutline->n_points    = (FT_UShort)numPoints;
321     anoutline->n_contours  = (FT_Short)numContours;
322     anoutline->flags      |= FT_OUTLINE_OWNER;
323 
324     return FT_Err_Ok;
325 
326   Fail:
327     anoutline->flags |= FT_OUTLINE_OWNER;
328     FT_Outline_Done_Internal( memory, anoutline );
329 
330     return error;
331   }
332 
333 
334   /* documentation is in ftoutln.h */
335 
336   FT_EXPORT_DEF( FT_Error )
FT_Outline_New(FT_Library library,FT_UInt numPoints,FT_Int numContours,FT_Outline * anoutline)337   FT_Outline_New( FT_Library   library,
338                   FT_UInt      numPoints,
339                   FT_Int       numContours,
340                   FT_Outline  *anoutline )
341   {
342     if ( !library )
343       return FT_THROW( Invalid_Library_Handle );
344 
345     return FT_Outline_New_Internal( library->memory, numPoints,
346                                     numContours, anoutline );
347   }
348 
349 
350   /* documentation is in ftoutln.h */
351 
352   FT_EXPORT_DEF( FT_Error )
FT_Outline_Check(FT_Outline * outline)353   FT_Outline_Check( FT_Outline*  outline )
354   {
355     if ( outline )
356     {
357       FT_Int  n_points   = outline->n_points;
358       FT_Int  n_contours = outline->n_contours;
359       FT_Int  end0, end;
360       FT_Int  n;
361 
362 
363       /* empty glyph? */
364       if ( n_points == 0 && n_contours == 0 )
365         return 0;
366 
367       /* check point and contour counts */
368       if ( n_points <= 0 || n_contours <= 0 )
369         goto Bad;
370 
371       end0 = end = -1;
372       for ( n = 0; n < n_contours; n++ )
373       {
374         end = outline->contours[n];
375 
376         /* note that we don't accept empty contours */
377         if ( end <= end0 || end >= n_points )
378           goto Bad;
379 
380         end0 = end;
381       }
382 
383       if ( end != n_points - 1 )
384         goto Bad;
385 
386       /* XXX: check the tags array */
387       return 0;
388     }
389 
390   Bad:
391     return FT_THROW( Invalid_Argument );
392   }
393 
394 
395   /* documentation is in ftoutln.h */
396 
397   FT_EXPORT_DEF( FT_Error )
FT_Outline_Copy(const FT_Outline * source,FT_Outline * target)398   FT_Outline_Copy( const FT_Outline*  source,
399                    FT_Outline        *target )
400   {
401     FT_Int  is_owner;
402 
403 
404     if ( !source            || !target            ||
405          source->n_points   != target->n_points   ||
406          source->n_contours != target->n_contours )
407       return FT_THROW( Invalid_Argument );
408 
409     if ( source == target )
410       return FT_Err_Ok;
411 
412     FT_ARRAY_COPY( target->points, source->points, source->n_points );
413 
414     FT_ARRAY_COPY( target->tags, source->tags, source->n_points );
415 
416     FT_ARRAY_COPY( target->contours, source->contours, source->n_contours );
417 
418     /* copy all flags, except the `FT_OUTLINE_OWNER' one */
419     is_owner      = target->flags & FT_OUTLINE_OWNER;
420     target->flags = source->flags;
421 
422     target->flags &= ~FT_OUTLINE_OWNER;
423     target->flags |= is_owner;
424 
425     return FT_Err_Ok;
426   }
427 
428 
429   FT_EXPORT_DEF( FT_Error )
FT_Outline_Done_Internal(FT_Memory memory,FT_Outline * outline)430   FT_Outline_Done_Internal( FT_Memory    memory,
431                             FT_Outline*  outline )
432   {
433     if ( memory && outline )
434     {
435       if ( outline->flags & FT_OUTLINE_OWNER )
436       {
437         FT_FREE( outline->points   );
438         FT_FREE( outline->tags     );
439         FT_FREE( outline->contours );
440       }
441       *outline = null_outline;
442 
443       return FT_Err_Ok;
444     }
445     else
446       return FT_THROW( Invalid_Argument );
447   }
448 
449 
450   /* documentation is in ftoutln.h */
451 
452   FT_EXPORT_DEF( FT_Error )
FT_Outline_Done(FT_Library library,FT_Outline * outline)453   FT_Outline_Done( FT_Library   library,
454                    FT_Outline*  outline )
455   {
456     /* check for valid `outline' in FT_Outline_Done_Internal() */
457 
458     if ( !library )
459       return FT_THROW( Invalid_Library_Handle );
460 
461     return FT_Outline_Done_Internal( library->memory, outline );
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 += xOffset;
534       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     first = 0;
553 
554     for ( n = 0; n < outline->n_contours; n++ )
555     {
556       last  = outline->contours[n];
557 
558       /* reverse point table */
559       {
560         FT_Vector*  p = outline->points + first;
561         FT_Vector*  q = outline->points + last;
562         FT_Vector   swap;
563 
564 
565         while ( p < q )
566         {
567           swap = *p;
568           *p   = *q;
569           *q   = swap;
570           p++;
571           q--;
572         }
573       }
574 
575       /* reverse tags table */
576       {
577         char*  p = outline->tags + first;
578         char*  q = outline->tags + last;
579         char   swap;
580 
581 
582         while ( p < q )
583         {
584           swap = *p;
585           *p   = *q;
586           *q   = swap;
587           p++;
588           q--;
589         }
590       }
591 
592       first = last + 1;
593     }
594 
595     outline->flags ^= FT_OUTLINE_REVERSE_FILL;
596   }
597 
598 
599   /* documentation is in ftoutln.h */
600 
601   FT_EXPORT_DEF( FT_Error )
FT_Outline_Render(FT_Library library,FT_Outline * outline,FT_Raster_Params * params)602   FT_Outline_Render( FT_Library         library,
603                      FT_Outline*        outline,
604                      FT_Raster_Params*  params )
605   {
606     FT_Error     error;
607     FT_Bool      update = FALSE;
608     FT_Renderer  renderer;
609     FT_ListNode  node;
610 
611 
612     if ( !library )
613       return FT_THROW( Invalid_Library_Handle );
614 
615     if ( !outline || !params )
616       return FT_THROW( Invalid_Argument );
617 
618     renderer = library->cur_renderer;
619     node     = library->renderers.head;
620 
621     params->source = (void*)outline;
622 
623     error = FT_ERR( Cannot_Render_Glyph );
624     while ( renderer )
625     {
626       error = renderer->raster_render( renderer->raster, params );
627       if ( !error || FT_ERR_NEQ( error, Cannot_Render_Glyph ) )
628         break;
629 
630       /* FT_Err_Cannot_Render_Glyph is returned if the render mode   */
631       /* is unsupported by the current renderer for this glyph image */
632       /* format                                                      */
633 
634       /* now, look for another renderer that supports the same */
635       /* format                                                */
636       renderer = FT_Lookup_Renderer( library, FT_GLYPH_FORMAT_OUTLINE,
637                                      &node );
638       update   = TRUE;
639     }
640 
641     /* if we changed the current renderer for the glyph image format */
642     /* we need to select it as the next current one                  */
643     if ( !error && update && renderer )
644       FT_Set_Renderer( library, renderer, 0, 0 );
645 
646     return error;
647   }
648 
649 
650   /* documentation is in ftoutln.h */
651 
652   FT_EXPORT_DEF( FT_Error )
FT_Outline_Get_Bitmap(FT_Library library,FT_Outline * outline,const FT_Bitmap * abitmap)653   FT_Outline_Get_Bitmap( FT_Library        library,
654                          FT_Outline*       outline,
655                          const FT_Bitmap  *abitmap )
656   {
657     FT_Raster_Params  params;
658 
659 
660     if ( !abitmap )
661       return FT_THROW( Invalid_Argument );
662 
663     /* other checks are delayed to FT_Outline_Render() */
664 
665     params.target = abitmap;
666     params.flags  = 0;
667 
668     if ( abitmap->pixel_mode == FT_PIXEL_MODE_GRAY  ||
669          abitmap->pixel_mode == FT_PIXEL_MODE_LCD   ||
670          abitmap->pixel_mode == FT_PIXEL_MODE_LCD_V )
671       params.flags |= FT_RASTER_FLAG_AA;
672 
673     return FT_Outline_Render( library, outline, &params );
674   }
675 
676 
677   /* documentation is in freetype.h */
678 
679   FT_EXPORT_DEF( void )
FT_Vector_Transform(FT_Vector * vector,const FT_Matrix * matrix)680   FT_Vector_Transform( FT_Vector*        vector,
681                        const FT_Matrix*  matrix )
682   {
683     FT_Pos  xz, yz;
684 
685 
686     if ( !vector || !matrix )
687       return;
688 
689     xz = FT_MulFix( vector->x, matrix->xx ) +
690          FT_MulFix( vector->y, matrix->xy );
691 
692     yz = FT_MulFix( vector->x, matrix->yx ) +
693          FT_MulFix( vector->y, matrix->yy );
694 
695     vector->x = xz;
696     vector->y = yz;
697   }
698 
699 
700   /* documentation is in ftoutln.h */
701 
702   FT_EXPORT_DEF( void )
FT_Outline_Transform(const FT_Outline * outline,const FT_Matrix * matrix)703   FT_Outline_Transform( const FT_Outline*  outline,
704                         const FT_Matrix*   matrix )
705   {
706     FT_Vector*  vec;
707     FT_Vector*  limit;
708 
709 
710     if ( !outline || !matrix )
711       return;
712 
713     vec   = outline->points;
714     limit = vec + outline->n_points;
715 
716     for ( ; vec < limit; vec++ )
717       FT_Vector_Transform( vec, matrix );
718   }
719 
720 
721 #if 0
722 
723 #define FT_OUTLINE_GET_CONTOUR( outline, c, first, last )  \
724   do {                                                     \
725     (first) = ( c > 0 ) ? (outline)->points +              \
726                             (outline)->contours[c - 1] + 1 \
727                         : (outline)->points;               \
728     (last) = (outline)->points + (outline)->contours[c];   \
729   } while ( 0 )
730 
731 
732   /* Is a point in some contour?                     */
733   /*                                                 */
734   /* We treat every point of the contour as if it    */
735   /* it were ON.  That is, we allow false positives, */
736   /* but disallow false negatives.  (XXX really?)    */
737   static FT_Bool
738   ft_contour_has( FT_Outline*  outline,
739                   FT_Short     c,
740                   FT_Vector*   point )
741   {
742     FT_Vector*  first;
743     FT_Vector*  last;
744     FT_Vector*  a;
745     FT_Vector*  b;
746     FT_UInt     n = 0;
747 
748 
749     FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
750 
751     for ( a = first; a <= last; a++ )
752     {
753       FT_Pos  x;
754       FT_Int  intersect;
755 
756 
757       b = ( a == last ) ? first : a + 1;
758 
759       intersect = ( a->y - point->y ) ^ ( b->y - point->y );
760 
761       /* a and b are on the same side */
762       if ( intersect >= 0 )
763       {
764         if ( intersect == 0 && a->y == point->y )
765         {
766           if ( ( a->x <= point->x && b->x >= point->x ) ||
767                ( a->x >= point->x && b->x <= point->x ) )
768             return 1;
769         }
770 
771         continue;
772       }
773 
774       x = a->x + ( b->x - a->x ) * (point->y - a->y ) / ( b->y - a->y );
775 
776       if ( x < point->x )
777         n++;
778       else if ( x == point->x )
779         return 1;
780     }
781 
782     return n & 1;
783   }
784 
785 
786   static FT_Bool
787   ft_contour_enclosed( FT_Outline*  outline,
788                        FT_UShort    c )
789   {
790     FT_Vector*  first;
791     FT_Vector*  last;
792     FT_Short    i;
793 
794 
795     FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
796 
797     for ( i = 0; i < outline->n_contours; i++ )
798     {
799       if ( i != c && ft_contour_has( outline, i, first ) )
800       {
801         FT_Vector*  pt;
802 
803 
804         for ( pt = first + 1; pt <= last; pt++ )
805           if ( !ft_contour_has( outline, i, pt ) )
806             return 0;
807 
808         return 1;
809       }
810     }
811 
812     return 0;
813   }
814 
815 
816   /* This version differs from the public one in that each */
817   /* part (contour not enclosed in another contour) of the */
818   /* outline is checked for orientation.  This is          */
819   /* necessary for some buggy CJK fonts.                   */
820   static FT_Orientation
821   ft_outline_get_orientation( FT_Outline*  outline )
822   {
823     FT_Short        i;
824     FT_Vector*      first;
825     FT_Vector*      last;
826     FT_Orientation  orient = FT_ORIENTATION_NONE;
827 
828 
829     first = outline->points;
830     for ( i = 0; i < outline->n_contours; i++, first = last + 1 )
831     {
832       FT_Vector*  point;
833       FT_Vector*  xmin_point;
834       FT_Pos      xmin;
835 
836 
837       last = outline->points + outline->contours[i];
838 
839       /* skip degenerate contours */
840       if ( last < first + 2 )
841         continue;
842 
843       if ( ft_contour_enclosed( outline, i ) )
844         continue;
845 
846       xmin       = first->x;
847       xmin_point = first;
848 
849       for ( point = first + 1; point <= last; point++ )
850       {
851         if ( point->x < xmin )
852         {
853           xmin       = point->x;
854           xmin_point = point;
855         }
856       }
857 
858       /* check the orientation of the contour */
859       {
860         FT_Vector*      prev;
861         FT_Vector*      next;
862         FT_Orientation  o;
863 
864 
865         prev = ( xmin_point == first ) ? last : xmin_point - 1;
866         next = ( xmin_point == last ) ? first : xmin_point + 1;
867 
868         if ( FT_Atan2( prev->x - xmin_point->x, prev->y - xmin_point->y ) >
869              FT_Atan2( next->x - xmin_point->x, next->y - xmin_point->y ) )
870           o = FT_ORIENTATION_POSTSCRIPT;
871         else
872           o = FT_ORIENTATION_TRUETYPE;
873 
874         if ( orient == FT_ORIENTATION_NONE )
875           orient = o;
876         else if ( orient != o )
877           return FT_ORIENTATION_NONE;
878       }
879     }
880 
881     return orient;
882   }
883 
884 #endif /* 0 */
885 
886 
887   /* documentation is in ftoutln.h */
888 
889   FT_EXPORT_DEF( FT_Error )
FT_Outline_Embolden(FT_Outline * outline,FT_Pos strength)890   FT_Outline_Embolden( FT_Outline*  outline,
891                        FT_Pos       strength )
892   {
893     return FT_Outline_EmboldenXY( outline, strength, strength );
894   }
895 
896 
897   /* documentation is in ftoutln.h */
898 
899   FT_EXPORT_DEF( FT_Error )
FT_Outline_EmboldenXY(FT_Outline * outline,FT_Pos xstrength,FT_Pos ystrength)900   FT_Outline_EmboldenXY( FT_Outline*  outline,
901                          FT_Pos       xstrength,
902                          FT_Pos       ystrength )
903   {
904     FT_Vector*  points;
905     FT_Vector   v_prev, v_first, v_next, v_cur;
906     FT_Int      c, n, first;
907     FT_Int      orientation;
908 
909 
910     if ( !outline )
911       return FT_THROW( Invalid_Argument );
912 
913     xstrength /= 2;
914     ystrength /= 2;
915     if ( xstrength == 0 && ystrength == 0 )
916       return FT_Err_Ok;
917 
918     orientation = FT_Outline_Get_Orientation( outline );
919     if ( orientation == FT_ORIENTATION_NONE )
920     {
921       if ( outline->n_contours )
922         return FT_THROW( Invalid_Argument );
923       else
924         return FT_Err_Ok;
925     }
926 
927     points = outline->points;
928 
929     first = 0;
930     for ( c = 0; c < outline->n_contours; c++ )
931     {
932       FT_Vector  in, out, shift;
933       FT_Fixed   l_in, l_out, l, q, d;
934       int        last = outline->contours[c];
935 
936 
937       v_first = points[first];
938       v_prev  = points[last];
939       v_cur   = v_first;
940 
941       /* compute incoming normalized vector */
942       in.x = v_cur.x - v_prev.x;
943       in.y = v_cur.y - v_prev.y;
944       l_in = FT_Vector_Length( &in );
945       if ( l_in )
946       {
947         in.x = FT_DivFix( in.x, l_in );
948         in.y = FT_DivFix( in.y, l_in );
949       }
950 
951       for ( n = first; n <= last; n++ )
952       {
953         if ( n < last )
954           v_next = points[n + 1];
955         else
956           v_next = v_first;
957 
958         /* compute outgoing normalized vector */
959         out.x = v_next.x - v_cur.x;
960         out.y = v_next.y - v_cur.y;
961         l_out = FT_Vector_Length( &out );
962         if ( l_out )
963         {
964           out.x = FT_DivFix( out.x, l_out );
965           out.y = FT_DivFix( out.y, l_out );
966         }
967 
968         d = FT_MulFix( in.x, out.x ) + FT_MulFix( in.y, out.y );
969 
970         /* shift only if turn is less than ~160 degrees */
971         if ( d > -0xF000L )
972         {
973           d = d + 0x10000L;
974 
975           /* shift components are aligned along lateral bisector */
976           /* and directed according to the outline orientation.  */
977           shift.x = in.y + out.y;
978           shift.y = in.x + out.x;
979 
980           if ( orientation == FT_ORIENTATION_TRUETYPE )
981             shift.x = -shift.x;
982           else
983             shift.y = -shift.y;
984 
985           /* restrict shift magnitude to better handle collapsing segments */
986           q = FT_MulFix( out.x, in.y ) - FT_MulFix( out.y, in.x );
987           if ( orientation == FT_ORIENTATION_TRUETYPE )
988             q = -q;
989 
990           l = FT_MIN( l_in, l_out );
991 
992           /* non-strict inequalities avoid divide-by-zero when q == l == 0 */
993           if ( FT_MulFix( xstrength, q ) <= FT_MulFix( d, l ) )
994             shift.x = FT_MulDiv( shift.x, xstrength, d );
995           else
996             shift.x = FT_MulDiv( shift.x, l, q );
997 
998 
999           if ( FT_MulFix( ystrength, q ) <= FT_MulFix( d, l ) )
1000             shift.y = FT_MulDiv( shift.y, ystrength, d );
1001           else
1002             shift.y = FT_MulDiv( shift.y, l, q );
1003         }
1004         else
1005           shift.x = shift.y = 0;
1006 
1007         outline->points[n].x = v_cur.x + xstrength + shift.x;
1008         outline->points[n].y = v_cur.y + ystrength + shift.y;
1009 
1010         in    = out;
1011         l_in  = l_out;
1012         v_cur = v_next;
1013       }
1014 
1015       first = last + 1;
1016     }
1017 
1018     return FT_Err_Ok;
1019   }
1020 
1021 
1022   /* documentation is in ftoutln.h */
1023 
1024   FT_EXPORT_DEF( FT_Orientation )
FT_Outline_Get_Orientation(FT_Outline * outline)1025   FT_Outline_Get_Orientation( FT_Outline*  outline )
1026   {
1027     FT_BBox     cbox;
1028     FT_Int      xshift, yshift;
1029     FT_Vector*  points;
1030     FT_Vector   v_prev, v_cur;
1031     FT_Int      c, n, first;
1032     FT_Pos      area = 0;
1033 
1034 
1035     if ( !outline || outline->n_points <= 0 )
1036       return FT_ORIENTATION_TRUETYPE;
1037 
1038     /* We use the nonzero winding rule to find the orientation.       */
1039     /* Since glyph outlines behave much more `regular' than arbitrary */
1040     /* cubic or quadratic curves, this test deals with the polygon    */
1041     /* only which is spanned up by the control points.                */
1042 
1043     FT_Outline_Get_CBox( outline, &cbox );
1044 
1045     xshift = FT_MSB( FT_ABS( cbox.xMax ) | FT_ABS( cbox.xMin ) ) - 14;
1046     xshift = FT_MAX( xshift, 0 );
1047 
1048     yshift = FT_MSB( cbox.yMax - cbox.yMin ) - 14;
1049     yshift = FT_MAX( yshift, 0 );
1050 
1051     points = outline->points;
1052 
1053     first = 0;
1054     for ( c = 0; c < outline->n_contours; c++ )
1055     {
1056       FT_Int  last = outline->contours[c];
1057 
1058 
1059       v_prev = points[last];
1060 
1061       for ( n = first; n <= last; n++ )
1062       {
1063         v_cur = points[n];
1064         area += ( ( v_cur.y - v_prev.y ) >> yshift ) *
1065                 ( ( v_cur.x + v_prev.x ) >> xshift );
1066         v_prev = v_cur;
1067       }
1068 
1069       first = last + 1;
1070     }
1071 
1072     if ( area > 0 )
1073       return FT_ORIENTATION_POSTSCRIPT;
1074     else if ( area < 0 )
1075       return FT_ORIENTATION_TRUETYPE;
1076     else
1077       return FT_ORIENTATION_NONE;
1078   }
1079 
1080 
1081 /* END */
1082