1/***************************************************************************/
2/*                                                                         */
3/*  ftoutln.c                                                              */
4/*                                                                         */
5/*    FreeType outline management (body).                                  */
6/*                                                                         */
7/*  Copyright 1996-2008, 2010, 2012-2014 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 )
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 )
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 )
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 )
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 )
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 )
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 )
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 )
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 += xOffset;
534      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    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
580
581        while ( p < q )
582        {
583          char  swap;
584
585
586          swap = *p;
587          *p   = *q;
588          *q   = swap;
589          p++;
590          q--;
591        }
592      }
593
594      first = last + 1;
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_Bool      update = FALSE;
610    FT_Renderer  renderer;
611    FT_ListNode  node;
612
613
614    if ( !library )
615      return FT_THROW( Invalid_Library_Handle );
616
617    if ( !outline || !params )
618      return FT_THROW( Invalid_Argument );
619
620    renderer = library->cur_renderer;
621    node     = library->renderers.head;
622
623    params->source = (void*)outline;
624
625    error = FT_ERR( Cannot_Render_Glyph );
626    while ( renderer )
627    {
628      error = renderer->raster_render( renderer->raster, params );
629      if ( !error || FT_ERR_NEQ( error, Cannot_Render_Glyph ) )
630        break;
631
632      /* FT_Err_Cannot_Render_Glyph is returned if the render mode   */
633      /* is unsupported by the current renderer for this glyph image */
634      /* format                                                      */
635
636      /* now, look for another renderer that supports the same */
637      /* format                                                */
638      renderer = FT_Lookup_Renderer( library, FT_GLYPH_FORMAT_OUTLINE,
639                                     &node );
640      update   = TRUE;
641    }
642
643    /* if we changed the current renderer for the glyph image format */
644    /* we need to select it as the next current one                  */
645    if ( !error && update && renderer )
646      FT_Set_Renderer( library, renderer, 0, 0 );
647
648    return error;
649  }
650
651
652  /* documentation is in ftoutln.h */
653
654  FT_EXPORT_DEF( FT_Error )
655  FT_Outline_Get_Bitmap( FT_Library        library,
656                         FT_Outline*       outline,
657                         const FT_Bitmap  *abitmap )
658  {
659    FT_Raster_Params  params;
660
661
662    if ( !abitmap )
663      return FT_THROW( Invalid_Argument );
664
665    /* other checks are delayed to FT_Outline_Render() */
666
667    params.target = abitmap;
668    params.flags  = 0;
669
670    if ( abitmap->pixel_mode == FT_PIXEL_MODE_GRAY  ||
671         abitmap->pixel_mode == FT_PIXEL_MODE_LCD   ||
672         abitmap->pixel_mode == FT_PIXEL_MODE_LCD_V )
673      params.flags |= FT_RASTER_FLAG_AA;
674
675    return FT_Outline_Render( library, outline, &params );
676  }
677
678
679  /* documentation is in freetype.h */
680
681  FT_EXPORT_DEF( void )
682  FT_Vector_Transform( FT_Vector*        vector,
683                       const FT_Matrix*  matrix )
684  {
685    FT_Pos  xz, yz;
686
687
688    if ( !vector || !matrix )
689      return;
690
691    xz = FT_MulFix( vector->x, matrix->xx ) +
692         FT_MulFix( vector->y, matrix->xy );
693
694    yz = FT_MulFix( vector->x, matrix->yx ) +
695         FT_MulFix( vector->y, matrix->yy );
696
697    vector->x = xz;
698    vector->y = yz;
699  }
700
701
702  /* documentation is in ftoutln.h */
703
704  FT_EXPORT_DEF( void )
705  FT_Outline_Transform( const FT_Outline*  outline,
706                        const FT_Matrix*   matrix )
707  {
708    FT_Vector*  vec;
709    FT_Vector*  limit;
710
711
712    if ( !outline || !matrix )
713      return;
714
715    vec   = outline->points;
716    limit = vec + outline->n_points;
717
718    for ( ; vec < limit; vec++ )
719      FT_Vector_Transform( vec, matrix );
720  }
721
722
723#if 0
724
725#define FT_OUTLINE_GET_CONTOUR( outline, c, first, last )  \
726  do                                                       \
727  {                                                        \
728    (first) = ( c > 0 ) ? (outline)->points +              \
729                            (outline)->contours[c - 1] + 1 \
730                        : (outline)->points;               \
731    (last) = (outline)->points + (outline)->contours[c];   \
732  } while ( 0 )
733
734
735  /* Is a point in some contour?                     */
736  /*                                                 */
737  /* We treat every point of the contour as if it    */
738  /* it were ON.  That is, we allow false positives, */
739  /* but disallow false negatives.  (XXX really?)    */
740  static FT_Bool
741  ft_contour_has( FT_Outline*  outline,
742                  FT_Short     c,
743                  FT_Vector*   point )
744  {
745    FT_Vector*  first;
746    FT_Vector*  last;
747    FT_Vector*  a;
748    FT_Vector*  b;
749    FT_UInt     n = 0;
750
751
752    FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
753
754    for ( a = first; a <= last; a++ )
755    {
756      FT_Pos  x;
757      FT_Int  intersect;
758
759
760      b = ( a == last ) ? first : a + 1;
761
762      intersect = ( a->y - point->y ) ^ ( b->y - point->y );
763
764      /* a and b are on the same side */
765      if ( intersect >= 0 )
766      {
767        if ( intersect == 0 && a->y == point->y )
768        {
769          if ( ( a->x <= point->x && b->x >= point->x ) ||
770               ( a->x >= point->x && b->x <= point->x ) )
771            return 1;
772        }
773
774        continue;
775      }
776
777      x = a->x + ( b->x - a->x ) * (point->y - a->y ) / ( b->y - a->y );
778
779      if ( x < point->x )
780        n++;
781      else if ( x == point->x )
782        return 1;
783    }
784
785    return n & 1;
786  }
787
788
789  static FT_Bool
790  ft_contour_enclosed( FT_Outline*  outline,
791                       FT_UShort    c )
792  {
793    FT_Vector*  first;
794    FT_Vector*  last;
795    FT_Short    i;
796
797
798    FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
799
800    for ( i = 0; i < outline->n_contours; i++ )
801    {
802      if ( i != c && ft_contour_has( outline, i, first ) )
803      {
804        FT_Vector*  pt;
805
806
807        for ( pt = first + 1; pt <= last; pt++ )
808          if ( !ft_contour_has( outline, i, pt ) )
809            return 0;
810
811        return 1;
812      }
813    }
814
815    return 0;
816  }
817
818
819  /* This version differs from the public one in that each */
820  /* part (contour not enclosed in another contour) of the */
821  /* outline is checked for orientation.  This is          */
822  /* necessary for some buggy CJK fonts.                   */
823  static FT_Orientation
824  ft_outline_get_orientation( FT_Outline*  outline )
825  {
826    FT_Short        i;
827    FT_Vector*      first;
828    FT_Vector*      last;
829    FT_Orientation  orient = FT_ORIENTATION_NONE;
830
831
832    first = outline->points;
833    for ( i = 0; i < outline->n_contours; i++, first = last + 1 )
834    {
835      FT_Vector*  point;
836      FT_Vector*  xmin_point;
837      FT_Pos      xmin;
838
839
840      last = outline->points + outline->contours[i];
841
842      /* skip degenerate contours */
843      if ( last < first + 2 )
844        continue;
845
846      if ( ft_contour_enclosed( outline, i ) )
847        continue;
848
849      xmin       = first->x;
850      xmin_point = first;
851
852      for ( point = first + 1; point <= last; point++ )
853      {
854        if ( point->x < xmin )
855        {
856          xmin       = point->x;
857          xmin_point = point;
858        }
859      }
860
861      /* check the orientation of the contour */
862      {
863        FT_Vector*      prev;
864        FT_Vector*      next;
865        FT_Orientation  o;
866
867
868        prev = ( xmin_point == first ) ? last : xmin_point - 1;
869        next = ( xmin_point == last ) ? first : xmin_point + 1;
870
871        if ( FT_Atan2( prev->x - xmin_point->x, prev->y - xmin_point->y ) >
872             FT_Atan2( next->x - xmin_point->x, next->y - xmin_point->y ) )
873          o = FT_ORIENTATION_POSTSCRIPT;
874        else
875          o = FT_ORIENTATION_TRUETYPE;
876
877        if ( orient == FT_ORIENTATION_NONE )
878          orient = o;
879        else if ( orient != o )
880          return FT_ORIENTATION_NONE;
881      }
882    }
883
884    return orient;
885  }
886
887#endif /* 0 */
888
889
890  /* documentation is in ftoutln.h */
891
892  FT_EXPORT_DEF( FT_Error )
893  FT_Outline_Embolden( FT_Outline*  outline,
894                       FT_Pos       strength )
895  {
896    return FT_Outline_EmboldenXY( outline, strength, strength );
897  }
898
899
900  /* documentation is in ftoutln.h */
901
902  FT_EXPORT_DEF( FT_Error )
903  FT_Outline_EmboldenXY( FT_Outline*  outline,
904                         FT_Pos       xstrength,
905                         FT_Pos       ystrength )
906  {
907    FT_Vector*  points;
908    FT_Vector   v_prev, v_first, v_next, v_cur;
909    FT_Int      c, n, first;
910    FT_Int      orientation;
911
912
913    if ( !outline )
914      return FT_THROW( Invalid_Argument );
915
916    xstrength /= 2;
917    ystrength /= 2;
918    if ( xstrength == 0 && ystrength == 0 )
919      return FT_Err_Ok;
920
921    orientation = FT_Outline_Get_Orientation( outline );
922    if ( orientation == FT_ORIENTATION_NONE )
923    {
924      if ( outline->n_contours )
925        return FT_THROW( Invalid_Argument );
926      else
927        return FT_Err_Ok;
928    }
929
930    points = outline->points;
931
932    first = 0;
933    for ( c = 0; c < outline->n_contours; c++ )
934    {
935      FT_Vector  in, out, shift;
936      FT_Fixed   l_in, l_out, l, q, d;
937      int        last = outline->contours[c];
938
939
940      v_first = points[first];
941      v_prev  = points[last];
942      v_cur   = v_first;
943
944      /* compute incoming normalized vector */
945      in.x = v_cur.x - v_prev.x;
946      in.y = v_cur.y - v_prev.y;
947      l_in = FT_Vector_Length( &in );
948      if ( l_in )
949      {
950        in.x = FT_DivFix( in.x, l_in );
951        in.y = FT_DivFix( in.y, l_in );
952      }
953
954      for ( n = first; n <= last; n++ )
955      {
956        if ( n < last )
957          v_next = points[n + 1];
958        else
959          v_next = v_first;
960
961        /* compute outgoing normalized vector */
962        out.x = v_next.x - v_cur.x;
963        out.y = v_next.y - v_cur.y;
964        l_out = FT_Vector_Length( &out );
965        if ( l_out )
966        {
967          out.x = FT_DivFix( out.x, l_out );
968          out.y = FT_DivFix( out.y, l_out );
969        }
970
971        d = FT_MulFix( in.x, out.x ) + FT_MulFix( in.y, out.y );
972
973        /* shift only if turn is less than ~160 degrees */
974        if ( d > -0xF000L )
975        {
976          d = d + 0x10000L;
977
978          /* shift components are aligned along lateral bisector */
979          /* and directed according to the outline orientation.  */
980          shift.x = in.y + out.y;
981          shift.y = in.x + out.x;
982
983          if ( orientation == FT_ORIENTATION_TRUETYPE )
984            shift.x = -shift.x;
985          else
986            shift.y = -shift.y;
987
988          /* restrict shift magnitude to better handle collapsing segments */
989          q = FT_MulFix( out.x, in.y ) - FT_MulFix( out.y, in.x );
990          if ( orientation == FT_ORIENTATION_TRUETYPE )
991            q = -q;
992
993          l = FT_MIN( l_in, l_out );
994
995          /* non-strict inequalities avoid divide-by-zero when q == l == 0 */
996          if ( FT_MulFix( xstrength, q ) <= FT_MulFix( d, l ) )
997            shift.x = FT_MulDiv( shift.x, xstrength, d );
998          else
999            shift.x = FT_MulDiv( shift.x, l, q );
1000
1001
1002          if ( FT_MulFix( ystrength, q ) <= FT_MulFix( d, l ) )
1003            shift.y = FT_MulDiv( shift.y, ystrength, d );
1004          else
1005            shift.y = FT_MulDiv( shift.y, l, q );
1006        }
1007        else
1008          shift.x = shift.y = 0;
1009
1010        outline->points[n].x = v_cur.x + xstrength + shift.x;
1011        outline->points[n].y = v_cur.y + ystrength + shift.y;
1012
1013        in    = out;
1014        l_in  = l_out;
1015        v_cur = v_next;
1016      }
1017
1018      first = last + 1;
1019    }
1020
1021    return FT_Err_Ok;
1022  }
1023
1024
1025  /* documentation is in ftoutln.h */
1026
1027  FT_EXPORT_DEF( FT_Orientation )
1028  FT_Outline_Get_Orientation( FT_Outline*  outline )
1029  {
1030    FT_BBox     cbox;
1031    FT_Int      xshift, yshift;
1032    FT_Vector*  points;
1033    FT_Vector   v_prev, v_cur;
1034    FT_Int      c, n, first;
1035    FT_Pos      area = 0;
1036
1037
1038    if ( !outline || outline->n_points <= 0 )
1039      return FT_ORIENTATION_TRUETYPE;
1040
1041    /* We use the nonzero winding rule to find the orientation.       */
1042    /* Since glyph outlines behave much more `regular' than arbitrary */
1043    /* cubic or quadratic curves, this test deals with the polygon    */
1044    /* only which is spanned up by the control points.                */
1045
1046    FT_Outline_Get_CBox( outline, &cbox );
1047
1048    xshift = FT_MSB( FT_ABS( cbox.xMax ) | FT_ABS( cbox.xMin ) ) - 14;
1049    xshift = FT_MAX( xshift, 0 );
1050
1051    yshift = FT_MSB( cbox.yMax - cbox.yMin ) - 14;
1052    yshift = FT_MAX( yshift, 0 );
1053
1054    points = outline->points;
1055
1056    first = 0;
1057    for ( c = 0; c < outline->n_contours; c++ )
1058    {
1059      FT_Int  last = outline->contours[c];
1060
1061
1062      v_prev = points[last];
1063
1064      for ( n = first; n <= last; n++ )
1065      {
1066        v_cur = points[n];
1067        area += ( ( v_cur.y - v_prev.y ) >> yshift ) *
1068                ( ( v_cur.x + v_prev.x ) >> xshift );
1069        v_prev = v_cur;
1070      }
1071
1072      first = last + 1;
1073    }
1074
1075    if ( area > 0 )
1076      return FT_ORIENTATION_POSTSCRIPT;
1077    else if ( area < 0 )
1078      return FT_ORIENTATION_TRUETYPE;
1079    else
1080      return FT_ORIENTATION_NONE;
1081  }
1082
1083
1084/* END */
1085