modules/freetype2/src/base/ftoutln.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftoutln.c                                                              */
   4 /*                                                                         */
   5 /*    FreeType outline management (body).                                  */
   6 /*                                                                         */
   7 /*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007 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_TRIGONOMETRY_H
  30
  31
  32   /*************************************************************************/
  33   /*                                                                       */
  34   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  35   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  36   /* messages during execution.                                            */
  37   /*                                                                       */
  38 #undef  FT_COMPONENT
  39 #define FT_COMPONENT  trace_outline
  40
  41
  42   static
  43   const FT_Outline  null_outline = { 0, 0, 0, 0, 0, 0 };
  44
  45
  46   /* documentation is in ftoutln.h */
  47
  48   FT_EXPORT_DEF( FT_Error )
  49   FT_Outline_Decompose( FT_Outline*              outline,
  50                         const FT_Outline_Funcs*  func_interface,
  51                         void*                    user )
  52   {
  53 #undef SCALED
  54 #define SCALED( x )  ( ( (x) << shift ) - delta )
  55
  56     FT_Vector   v_last;
  57     FT_Vector   v_control;
  58     FT_Vector   v_start;
  59
  60     FT_Vector*  point;
  61     FT_Vector*  limit;
  62     char*       tags;
  63
  64     FT_Error    error;
  65
  66     FT_Int   n;         /* index of contour in outline     */
  67     FT_UInt  first;     /* index of first point in contour */
  68     FT_Int   tag;       /* current point's state           */
  69
  70     FT_Int   shift;
  71     FT_Pos   delta;
  72
  73
  74     if ( !outline || !func_interface )
  75       return FT_Err_Invalid_Argument;
  76
  77     shift = func_interface->shift;
  78     delta = func_interface->delta;
  79     first = 0;
  80
  81     for ( n = 0; n < outline->n_contours; n++ )
  82     {
  83       FT_Int  last;  /* index of last point in contour */
  84
  85
  86       last = outline->contours[n];
  87       if ( last < 0 )
  88         goto Invalid_Outline;
  89       limit = outline->points + last;
  90
  91       v_start = outline->points[first];
  92       v_last  = outline->points[last];
  93
  94       v_start.x = SCALED( v_start.x ); v_start.y = SCALED( v_start.y );
  95       v_last.x  = SCALED( v_last.x );  v_last.y  = SCALED( v_last.y );
  96
  97       v_control = v_start;
  98
  99       point = outline->points + first;
 100       tags  = outline->tags  + first;
 101       tag   = FT_CURVE_TAG( tags[0] );
 102
 103       /* A contour cannot start with a cubic control point! */
 104       if ( tag == FT_CURVE_TAG_CUBIC )
 105         goto Invalid_Outline;
 106
 107       /* check first point to determine origin */
 108       if ( tag == FT_CURVE_TAG_CONIC )
 109       {
 110         /* first point is conic control.  Yes, this happens. */
 111         if ( FT_CURVE_TAG( outline->tags[last] ) == FT_CURVE_TAG_ON )
 112         {
 113           /* start at last point if it is on the curve */
 114           v_start = v_last;
 115           limit--;
 116         }
 117         else
 118         {
 119           /* if both first and last points are conic,         */
 120           /* start at their middle and record its position    */
 121           /* for closure                                      */
 122           v_start.x = ( v_start.x + v_last.x ) / 2;
 123           v_start.y = ( v_start.y + v_last.y ) / 2;
 124
 125           v_last = v_start;
 126         }
 127         point--;
 128         tags--;
 129       }
 130
 131       error = func_interface->move_to( &v_start, user );
 132       if ( error )
 133         goto Exit;
 134
 135       while ( point < limit )
 136       {
 137         point++;
 138         tags++;
 139
 140         tag = FT_CURVE_TAG( tags[0] );
 141         switch ( tag )
 142         {
 143         case FT_CURVE_TAG_ON:  /* emit a single line_to */
 144           {
 145             FT_Vector  vec;
 146
 147
 148             vec.x = SCALED( point->x );
 149             vec.y = SCALED( point->y );
 150
 151             error = func_interface->line_to( &vec, user );
 152             if ( error )
 153               goto Exit;
 154             continue;
 155           }
 156
 157         case FT_CURVE_TAG_CONIC:  /* consume conic arcs */
 158           v_control.x = SCALED( point->x );
 159           v_control.y = SCALED( point->y );
 160
 161         Do_Conic:
 162           if ( point < limit )
 163           {
 164             FT_Vector  vec;
 165             FT_Vector  v_middle;
 166
 167
 168             point++;
 169             tags++;
 170             tag = FT_CURVE_TAG( tags[0] );
 171
 172             vec.x = SCALED( point->x );
 173             vec.y = SCALED( point->y );
 174
 175             if ( tag == FT_CURVE_TAG_ON )
 176             {
 177               error = func_interface->conic_to( &v_control, &vec, user );
 178               if ( error )
 179                 goto Exit;
 180               continue;
 181             }
 182
 183             if ( tag != FT_CURVE_TAG_CONIC )
 184               goto Invalid_Outline;
 185
 186             v_middle.x = ( v_control.x + vec.x ) / 2;
 187             v_middle.y = ( v_control.y + vec.y ) / 2;
 188
 189             error = func_interface->conic_to( &v_control, &v_middle, user );
 190             if ( error )
 191               goto Exit;
 192
 193             v_control = vec;
 194             goto Do_Conic;
 195           }
 196
 197           error = func_interface->conic_to( &v_control, &v_start, user );
 198           goto Close;
 199
 200         default:  /* FT_CURVE_TAG_CUBIC */
 201           {
 202             FT_Vector  vec1, vec2;
 203
 204
 205             if ( point + 1 > limit                             ||
 206                  FT_CURVE_TAG( tags[1] ) != FT_CURVE_TAG_CUBIC )
 207               goto Invalid_Outline;
 208
 209             point += 2;
 210             tags  += 2;
 211
 212             vec1.x = SCALED( point[-2].x ); vec1.y = SCALED( point[-2].y );
 213             vec2.x = SCALED( point[-1].x ); vec2.y = SCALED( point[-1].y );
 214
 215             if ( point <= limit )
 216             {
 217               FT_Vector  vec;
 218
 219
 220               vec.x = SCALED( point->x );
 221               vec.y = SCALED( point->y );
 222
 223               error = func_interface->cubic_to( &vec1, &vec2, &vec, user );
 224               if ( error )
 225                 goto Exit;
 226               continue;
 227             }
 228
 229             error = func_interface->cubic_to( &vec1, &vec2, &v_start, user );
 230             goto Close;
 231           }
 232         }
 233       }
 234
 235       /* close the contour with a line segment */
 236       error = func_interface->line_to( &v_start, user );
 237
 238     Close:
 239       if ( error )
 240         goto Exit;
 241
 242       first = last + 1;
 243     }
 244
 245     return 0;
 246
 247   Exit:
 248     return error;
 249
 250   Invalid_Outline:
 251     return FT_Err_Invalid_Outline;
 252   }
 253
 254
 255   FT_EXPORT_DEF( FT_Error )
 256   FT_Outline_New_Internal( FT_Memory    memory,
 257                            FT_UInt      numPoints,
 258                            FT_Int       numContours,
 259                            FT_Outline  *anoutline )
 260   {
 261     FT_Error  error;
 262
 263
 264     if ( !anoutline || !memory )
 265       return FT_Err_Invalid_Argument;
 266
 267     *anoutline = null_outline;
 268
 269     if ( FT_NEW_ARRAY( anoutline->points,   numPoints * 2L ) ||
 270          FT_NEW_ARRAY( anoutline->tags,     numPoints      ) ||
 271          FT_NEW_ARRAY( anoutline->contours, numContours    ) )
 272       goto Fail;
 273
 274     anoutline->n_points    = (FT_UShort)numPoints;
 275     anoutline->n_contours  = (FT_Short)numContours;
 276     anoutline->flags      |= FT_OUTLINE_OWNER;
 277
 278     return FT_Err_Ok;
 279
 280   Fail:
 281     anoutline->flags |= FT_OUTLINE_OWNER;
 282     FT_Outline_Done_Internal( memory, anoutline );
 283
 284     return error;
 285   }
 286
 287
 288   /* documentation is in ftoutln.h */
 289
 290   FT_EXPORT_DEF( FT_Error )
 291   FT_Outline_New( FT_Library   library,
 292                   FT_UInt      numPoints,
 293                   FT_Int       numContours,
 294                   FT_Outline  *anoutline )
 295   {
 296     if ( !library )
 297       return FT_Err_Invalid_Library_Handle;
 298
 299     return FT_Outline_New_Internal( library->memory, numPoints,
 300                                     numContours, anoutline );
 301   }
 302
 303
 304   /* documentation is in ftoutln.h */
 305
 306   FT_EXPORT_DEF( FT_Error )
 307   FT_Outline_Check( FT_Outline*  outline )
 308   {
 309     if ( outline )
 310     {
 311       FT_Int  n_points   = outline->n_points;
 312       FT_Int  n_contours = outline->n_contours;
 313       FT_Int  end0, end;
 314       FT_Int  n;
 315
 316
 317       /* empty glyph? */
 318       if ( n_points == 0 && n_contours == 0 )
 319         return 0;
 320
 321       /* check point and contour counts */
 322       if ( n_points <= 0 || n_contours <= 0 )
 323         goto Bad;
 324
 325       end0 = end = -1;
 326       for ( n = 0; n < n_contours; n++ )
 327       {
 328         end = outline->contours[n];
 329
 330         /* note that we don't accept empty contours */
 331         if ( end <= end0 || end >= n_points )
 332           goto Bad;
 333
 334         end0 = end;
 335       }
 336
 337       if ( end != n_points - 1 )
 338         goto Bad;
 339
 340       /* XXX: check the tags array */
 341       return 0;
 342     }
 343
 344   Bad:
 345     return FT_Err_Invalid_Argument;
 346   }
 347
 348
 349   /* documentation is in ftoutln.h */
 350
 351   FT_EXPORT_DEF( FT_Error )
 352   FT_Outline_Copy( const FT_Outline*  source,
 353                    FT_Outline        *target )
 354   {
 355     FT_Int  is_owner;
 356
 357
 358     if ( !source            || !target            ||
 359          source->n_points   != target->n_points   ||
 360          source->n_contours != target->n_contours )
 361       return FT_Err_Invalid_Argument;
 362
 363     if ( source == target )
 364       return FT_Err_Ok;
 365
 366     FT_ARRAY_COPY( target->points, source->points, source->n_points );
 367
 368     FT_ARRAY_COPY( target->tags, source->tags, source->n_points );
 369
 370     FT_ARRAY_COPY( target->contours, source->contours, source->n_contours );
 371
 372     /* copy all flags, except the `FT_OUTLINE_OWNER' one */
 373     is_owner      = target->flags & FT_OUTLINE_OWNER;
 374     target->flags = source->flags;
 375
 376     target->flags &= ~FT_OUTLINE_OWNER;
 377     target->flags |= is_owner;
 378
 379     return FT_Err_Ok;
 380   }
 381
 382
 383   FT_EXPORT_DEF( FT_Error )
 384   FT_Outline_Done_Internal( FT_Memory    memory,
 385                             FT_Outline*  outline )
 386   {
 387     if ( memory && outline )
 388     {
 389       if ( outline->flags & FT_OUTLINE_OWNER )
 390       {
 391         FT_FREE( outline->points   );
 392         FT_FREE( outline->tags     );
 393         FT_FREE( outline->contours );
 394       }
 395       *outline = null_outline;
 396
 397       return FT_Err_Ok;
 398     }
 399     else
 400       return FT_Err_Invalid_Argument;
 401   }
 402
 403
 404   /* documentation is in ftoutln.h */
 405
 406   FT_EXPORT_DEF( FT_Error )
 407   FT_Outline_Done( FT_Library   library,
 408                    FT_Outline*  outline )
 409   {
 410     /* check for valid `outline' in FT_Outline_Done_Internal() */
 411
 412     if ( !library )
 413       return FT_Err_Invalid_Library_Handle;
 414
 415     return FT_Outline_Done_Internal( library->memory, outline );
 416   }
 417
 418
 419   /* documentation is in ftoutln.h */
 420
 421   FT_EXPORT_DEF( void )
 422   FT_Outline_Get_CBox( const FT_Outline*  outline,
 423                        FT_BBox           *acbox )
 424   {
 425     FT_Pos  xMin, yMin, xMax, yMax;
 426
 427
 428     if ( outline && acbox )
 429     {
 430       if ( outline->n_points == 0 )
 431       {
 432         xMin = 0;
 433         yMin = 0;
 434         xMax = 0;
 435         yMax = 0;
 436       }
 437       else
 438       {
 439         FT_Vector*  vec   = outline->points;
 440         FT_Vector*  limit = vec + outline->n_points;
 441
 442
 443         xMin = xMax = vec->x;
 444         yMin = yMax = vec->y;
 445         vec++;
 446
 447         for ( ; vec < limit; vec++ )
 448         {
 449           FT_Pos  x, y;
 450
 451
 452           x = vec->x;
 453           if ( x < xMin ) xMin = x;
 454           if ( x > xMax ) xMax = x;
 455
 456           y = vec->y;
 457           if ( y < yMin ) yMin = y;
 458           if ( y > yMax ) yMax = y;
 459         }
 460       }
 461       acbox->xMin = xMin;
 462       acbox->xMax = xMax;
 463       acbox->yMin = yMin;
 464       acbox->yMax = yMax;
 465     }
 466   }
 467
 468
 469   /* documentation is in ftoutln.h */
 470
 471   FT_EXPORT_DEF( void )
 472   FT_Outline_Translate( const FT_Outline*  outline,
 473                         FT_Pos             xOffset,
 474                         FT_Pos             yOffset )
 475   {
 476     FT_UShort   n;
 477     FT_Vector*  vec;
 478
 479
 480     if ( !outline )
 481       return;
 482
 483     vec = outline->points;
 484
 485     for ( n = 0; n < outline->n_points; n++ )
 486     {
 487       vec->x += xOffset;
 488       vec->y += yOffset;
 489       vec++;
 490     }
 491   }
 492
 493
 494   /* documentation is in ftoutln.h */
 495
 496   FT_EXPORT_DEF( void )
 497   FT_Outline_Reverse( FT_Outline*  outline )
 498   {
 499     FT_UShort  n;
 500     FT_Int     first, last;
 501
 502
 503     if ( !outline )
 504       return;
 505
 506     first = 0;
 507
 508     for ( n = 0; n < outline->n_contours; n++ )
 509     {
 510       last  = outline->contours[n];
 511
 512       /* reverse point table */
 513       {
 514         FT_Vector*  p = outline->points + first;
 515         FT_Vector*  q = outline->points + last;
 516         FT_Vector   swap;
 517
 518
 519         while ( p < q )
 520         {
 521           swap = *p;
 522           *p   = *q;
 523           *q   = swap;
 524           p++;
 525           q--;
 526         }
 527       }
 528
 529       /* reverse tags table */
 530       {
 531         char*  p = outline->tags + first;
 532         char*  q = outline->tags + last;
 533         char   swap;
 534
 535
 536         while ( p < q )
 537         {
 538           swap = *p;
 539           *p   = *q;
 540           *q   = swap;
 541           p++;
 542           q--;
 543         }
 544       }
 545
 546       first = last + 1;
 547     }
 548
 549     outline->flags ^= FT_OUTLINE_REVERSE_FILL;
 550   }
 551
 552
 553   /* documentation is in ftoutln.h */
 554
 555   FT_EXPORT_DEF( FT_Error )
 556   FT_Outline_Render( FT_Library         library,
 557                      FT_Outline*        outline,
 558                      FT_Raster_Params*  params )
 559   {
 560     FT_Error     error;
 561     FT_Bool      update = 0;
 562     FT_Renderer  renderer;
 563     FT_ListNode  node;
 564
 565
 566     if ( !library )
 567       return FT_Err_Invalid_Library_Handle;
 568
 569     if ( !outline || !params )
 570       return FT_Err_Invalid_Argument;
 571
 572     renderer = library->cur_renderer;
 573     node     = library->renderers.head;
 574
 575     params->source = (void*)outline;
 576
 577     error = FT_Err_Cannot_Render_Glyph;
 578     while ( renderer )
 579     {
 580       error = renderer->raster_render( renderer->raster, params );
 581       if ( !error || FT_ERROR_BASE( error ) != FT_Err_Cannot_Render_Glyph )
 582         break;
 583
 584       /* FT_Err_Cannot_Render_Glyph is returned if the render mode   */
 585       /* is unsupported by the current renderer for this glyph image */
 586       /* format                                                      */
 587
 588       /* now, look for another renderer that supports the same */
 589       /* format                                                */
 590       renderer = FT_Lookup_Renderer( library, FT_GLYPH_FORMAT_OUTLINE,
 591                                      &node );
 592       update   = 1;
 593     }
 594
 595     /* if we changed the current renderer for the glyph image format */
 596     /* we need to select it as the next current one                  */
 597     if ( !error && update && renderer )
 598       FT_Set_Renderer( library, renderer, 0, 0 );
 599
 600     return error;
 601   }
 602
 603
 604   /* documentation is in ftoutln.h */
 605
 606   FT_EXPORT_DEF( FT_Error )
 607   FT_Outline_Get_Bitmap( FT_Library        library,
 608                          FT_Outline*       outline,
 609                          const FT_Bitmap  *abitmap )
 610   {
 611     FT_Raster_Params  params;
 612
 613
 614     if ( !abitmap )
 615       return FT_Err_Invalid_Argument;
 616
 617     /* other checks are delayed to FT_Outline_Render() */
 618
 619     params.target = abitmap;
 620     params.flags  = 0;
 621
 622     if ( abitmap->pixel_mode == FT_PIXEL_MODE_GRAY  ||
 623          abitmap->pixel_mode == FT_PIXEL_MODE_LCD   ||
 624          abitmap->pixel_mode == FT_PIXEL_MODE_LCD_V )
 625       params.flags |= FT_RASTER_FLAG_AA;
 626
 627     return FT_Outline_Render( library, outline, &params );
 628   }
 629
 630
 631   /* documentation is in freetype.h */
 632
 633   FT_EXPORT_DEF( void )
 634   FT_Vector_Transform( FT_Vector*        vector,
 635                        const FT_Matrix*  matrix )
 636   {
 637     FT_Pos  xz, yz;
 638
 639
 640     if ( !vector || !matrix )
 641       return;
 642
 643     xz = FT_MulFix( vector->x, matrix->xx ) +
 644          FT_MulFix( vector->y, matrix->xy );
 645
 646     yz = FT_MulFix( vector->x, matrix->yx ) +
 647          FT_MulFix( vector->y, matrix->yy );
 648
 649     vector->x = xz;
 650     vector->y = yz;
 651   }
 652
 653
 654   /* documentation is in ftoutln.h */
 655
 656   FT_EXPORT_DEF( void )
 657   FT_Outline_Transform( const FT_Outline*  outline,
 658                         const FT_Matrix*   matrix )
 659   {
 660     FT_Vector*  vec;
 661     FT_Vector*  limit;
 662
 663
 664     if ( !outline || !matrix )
 665       return;
 666
 667     vec   = outline->points;
 668     limit = vec + outline->n_points;
 669
 670     for ( ; vec < limit; vec++ )
 671       FT_Vector_Transform( vec, matrix );
 672   }
 673
 674
 675 #if 0
 676
 677 #define FT_OUTLINE_GET_CONTOUR( outline, c, first, last )  \
 678   do {                                                     \
 679     (first) = ( c > 0 ) ? (outline)->points +              \
 680                             (outline)->contours[c - 1] + 1 \
 681                         : (outline)->points;               \
 682     (last) = (outline)->points + (outline)->contours[c];   \
 683   } while ( 0 )
 684
 685
 686   /* Is a point in some contour?                     */
 687   /*                                                 */
 688   /* We treat every point of the contour as if it    */
 689   /* it were ON.  That is, we allow false positives, */
 690   /* but disallow false negatives.  (XXX really?)    */
 691   static FT_Bool
 692   ft_contour_has( FT_Outline*  outline,
 693                   FT_Short     c,
 694                   FT_Vector*   point )
 695   {
 696     FT_Vector*  first;
 697     FT_Vector*  last;
 698     FT_Vector*  a;
 699     FT_Vector*  b;
 700     FT_UInt     n = 0;
 701
 702
 703     FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
 704
 705     for ( a = first; a <= last; a++ )
 706     {
 707       FT_Pos  x;
 708       FT_Int  intersect;
 709
 710
 711       b = ( a == last ) ? first : a + 1;
 712
 713       intersect = ( a->y - point->y ) ^ ( b->y - point->y );
 714
 715       /* a and b are on the same side */
 716       if ( intersect >= 0 )
 717       {
 718         if ( intersect == 0 && a->y == point->y )
 719         {
 720           if ( ( a->x <= point->x && b->x >= point->x ) ||
 721                ( a->x >= point->x && b->x <= point->x ) )
 722             return 1;
 723         }
 724
 725         continue;
 726       }
 727
 728       x = a->x + ( b->x - a->x ) * (point->y - a->y ) / ( b->y - a->y );
 729
 730       if ( x < point->x )
 731         n++;
 732       else if ( x == point->x )
 733         return 1;
 734     }
 735
 736     return ( n % 2 );
 737   }
 738
 739
 740   static FT_Bool
 741   ft_contour_enclosed( FT_Outline*  outline,
 742                        FT_UShort    c )
 743   {
 744     FT_Vector*  first;
 745     FT_Vector*  last;
 746     FT_Short    i;
 747
 748
 749     FT_OUTLINE_GET_CONTOUR( outline, c, first, last );
 750
 751     for ( i = 0; i < outline->n_contours; i++ )
 752     {
 753       if ( i != c && ft_contour_has( outline, i, first ) )
 754       {
 755         FT_Vector*  pt;
 756
 757
 758         for ( pt = first + 1; pt <= last; pt++ )
 759           if ( !ft_contour_has( outline, i, pt ) )
 760             return 0;
 761
 762         return 1;
 763       }
 764     }
 765
 766     return 0;
 767   }
 768
 769
 770   /* This version differs from the public one in that each */
 771   /* part (contour not enclosed in another contour) of the */
 772   /* outline is checked for orientation.  This is          */
 773   /* necessary for some buggy CJK fonts.                   */
 774   static FT_Orientation
 775   ft_outline_get_orientation( FT_Outline*  outline )
 776   {
 777     FT_Short        i;
 778     FT_Vector*      first;
 779     FT_Vector*      last;
 780     FT_Orientation  orient = FT_ORIENTATION_NONE;
 781
 782
 783     first = outline->points;
 784     for ( i = 0; i < outline->n_contours; i++, first = last + 1 )
 785     {
 786       FT_Vector*  point;
 787       FT_Vector*  xmin_point;
 788       FT_Pos      xmin;
 789
 790
 791       last = outline->points + outline->contours[i];
 792
 793       /* skip degenerate contours */
 794       if ( last < first + 2 )
 795         continue;
 796
 797       if ( ft_contour_enclosed( outline, i ) )
 798         continue;
 799
 800       xmin       = first->x;
 801       xmin_point = first;
 802
 803       for ( point = first + 1; point <= last; point++ )
 804       {
 805         if ( point->x < xmin )
 806         {
 807           xmin       = point->x;
 808           xmin_point = point;
 809         }
 810       }
 811
 812       /* check the orientation of the contour */
 813       {
 814         FT_Vector*      prev;
 815         FT_Vector*      next;
 816         FT_Orientation  o;
 817
 818
 819         prev = ( xmin_point == first ) ? last : xmin_point - 1;
 820         next = ( xmin_point == last ) ? first : xmin_point + 1;
 821
 822         if ( FT_Atan2( prev->x - xmin_point->x, prev->y - xmin_point->y ) >
 823              FT_Atan2( next->x - xmin_point->x, next->y - xmin_point->y ) )
 824           o = FT_ORIENTATION_POSTSCRIPT;
 825         else
 826           o = FT_ORIENTATION_TRUETYPE;
 827
 828         if ( orient == FT_ORIENTATION_NONE )
 829           orient = o;
 830         else if ( orient != o )
 831           return FT_ORIENTATION_NONE;
 832       }
 833     }
 834
 835     return orient;
 836   }
 837
 838 #endif /* 0 */
 839
 840
 841   /* documentation is in ftoutln.h */
 842
 843   FT_EXPORT_DEF( FT_Error )
 844   FT_Outline_Embolden( FT_Outline*  outline,
 845                        FT_Pos       strength )
 846   {
 847     FT_Vector*  points;
 848     FT_Vector   v_prev, v_first, v_next, v_cur;
 849     FT_Angle    rotate, angle_in, angle_out;
 850     FT_Int      c, n, first;
 851     FT_Int      orientation;
 852
 853
 854     if ( !outline )
 855       return FT_Err_Invalid_Argument;
 856
 857     strength /= 2;
 858     if ( strength == 0 )
 859       return FT_Err_Ok;
 860
 861     orientation = FT_Outline_Get_Orientation( outline );
 862     if ( orientation == FT_ORIENTATION_NONE )
 863     {
 864       if ( outline->n_contours )
 865         return FT_Err_Invalid_Argument;
 866       else
 867         return FT_Err_Ok;
 868     }
 869
 870     if ( orientation == FT_ORIENTATION_TRUETYPE )
 871       rotate = -FT_ANGLE_PI2;
 872     else
 873       rotate = FT_ANGLE_PI2;
 874
 875     points = outline->points;
 876
 877     first = 0;
 878     for ( c = 0; c < outline->n_contours; c++ )
 879     {
 880       int  last = outline->contours[c];
 881
 882
 883       v_first = points[first];
 884       v_prev  = points[last];
 885       v_cur   = v_first;
 886
 887       for ( n = first; n <= last; n++ )
 888       {
 889         FT_Vector  in, out;
 890         FT_Angle   angle_diff;
 891         FT_Pos     d;
 892         FT_Fixed   scale;
 893
 894
 895         if ( n < last )
 896           v_next = points[n + 1];
 897         else
 898           v_next = v_first;
 899
 900         /* compute the in and out vectors */
 901         in.x = v_cur.x - v_prev.x;
 902         in.y = v_cur.y - v_prev.y;
 903
 904         out.x = v_next.x - v_cur.x;
 905         out.y = v_next.y - v_cur.y;
 906
 907         angle_in   = FT_Atan2( in.x, in.y );
 908         angle_out  = FT_Atan2( out.x, out.y );
 909         angle_diff = FT_Angle_Diff( angle_in, angle_out );
 910         scale      = FT_Cos( angle_diff / 2 );
 911
 912         if ( scale < 0x4000L && scale > -0x4000L )
 913           in.x = in.y = 0;
 914         else
 915         {
 916           d = FT_DivFix( strength, scale );
 917
 918           FT_Vector_From_Polar( &in, d, angle_in + angle_diff / 2 - rotate );
 919         }
 920
 921         outline->points[n].x = v_cur.x + strength + in.x;
 922         outline->points[n].y = v_cur.y + strength + in.y;
 923
 924         v_prev = v_cur;
 925         v_cur  = v_next;
 926       }
 927
 928       first = last + 1;
 929     }
 930
 931     return FT_Err_Ok;
 932   }
 933
 934
 935   /* documentation is in ftoutln.h */
 936
 937   FT_EXPORT_DEF( FT_Orientation )
 938   FT_Outline_Get_Orientation( FT_Outline*  outline )
 939   {
 940     FT_Pos      xmin       = 32768L;
 941     FT_Pos      xmin_ymin  = 32768L;
 942     FT_Pos      xmin_ymax  = -32768L;
 943     FT_Vector*  xmin_first = NULL;
 944     FT_Vector*  xmin_last  = NULL;
 945
 946     short*      contour;
 947
 948     FT_Vector*  first;
 949     FT_Vector*  last;
 950     FT_Vector*  prev;
 951     FT_Vector*  point;
 952
 953     int             i;
 954     FT_Pos          ray_y[3];
 955     FT_Orientation  result[3];
 956
 957
 958     if ( !outline || outline->n_points <= 0 )
 959       return FT_ORIENTATION_TRUETYPE;
 960
 961     /* We use the nonzero winding rule to find the orientation.       */
 962     /* Since glyph outlines behave much more `regular' than arbitrary */
 963     /* cubic or quadratic curves, this test deals with the polygon    */
 964     /* only which is spanned up by the control points.                */
 965
 966     first = outline->points;
 967     for ( contour = outline->contours;
 968           contour < outline->contours + outline->n_contours;
 969           contour++, first = last + 1 )
 970     {
 971       FT_Pos  contour_xmin = 32768L;
 972       FT_Pos  contour_xmax = -32768L;
 973       FT_Pos  contour_ymin = 32768L;
 974       FT_Pos  contour_ymax = -32768L;
 975
 976
 977       last = outline->points + *contour;
 978
 979       /* skip degenerate contours */
 980       if ( last < first + 2 )
 981         continue;
 982
 983       for ( point = first; point <= last; ++point )
 984       {
 985         if ( point->x < contour_xmin )
 986           contour_xmin = point->x;
 987
 988         if ( point->x > contour_xmax )
 989           contour_xmax = point->x;
 990
 991         if ( point->y < contour_ymin )
 992           contour_ymin = point->y;
 993
 994         if ( point->y > contour_ymax )
 995           contour_ymax = point->y;
 996       }
 997
 998       if ( contour_xmin < xmin          &&
 999            contour_xmin != contour_xmax &&
1000            contour_ymin != contour_ymax )
1001       {
1002         xmin       = contour_xmin;
1003         xmin_ymin  = contour_ymin;
1004         xmin_ymax  = contour_ymax;
1005         xmin_first = first;
1006         xmin_last  = last;
1007       }
1008     }
1009
1010     if ( xmin == 32768 )
1011       return FT_ORIENTATION_TRUETYPE;
1012
1013     ray_y[0] = ( xmin_ymin * 3 + xmin_ymax     ) >> 2;
1014     ray_y[1] = ( xmin_ymin     + xmin_ymax     ) >> 1;
1015     ray_y[2] = ( xmin_ymin     + xmin_ymax * 3 ) >> 2;
1016
1017     for ( i = 0; i < 3; i++ )
1018     {
1019       FT_Pos      left_x;
1020       FT_Pos      right_x;
1021       FT_Vector*  left1;
1022       FT_Vector*  left2;
1023       FT_Vector*  right1;
1024       FT_Vector*  right2;
1025
1026
1027     RedoRay:
1028       left_x  = 32768L;
1029       right_x = -32768L;
1030
1031       left1 = left2 = right1 = right2 = NULL;
1032
1033       prev = xmin_last;
1034       for ( point = xmin_first; point <= xmin_last; prev = point, ++point )
1035       {
1036         FT_Pos  tmp_x;
1037
1038
1039         if ( point->y == ray_y[i] || prev->y == ray_y[i] )
1040         {
1041           ray_y[i]++;
1042           goto RedoRay;
1043         }
1044
1045         if ( ( point->y < ray_y[i] && prev->y < ray_y[i] ) ||
1046              ( point->y > ray_y[i] && prev->y > ray_y[i] ) )
1047           continue;
1048
1049         tmp_x = FT_MulDiv( point->x - prev->x,
1050                            ray_y[i] - prev->y,
1051                            point->y - prev->y ) + prev->x;
1052
1053         if ( tmp_x < left_x )
1054         {
1055           left_x = tmp_x;
1056           left1  = prev;
1057           left2  = point;
1058         }
1059
1060         if ( tmp_x > right_x )
1061         {
1062           right_x = tmp_x;
1063           right1  = prev;
1064           right2  = point;
1065         }
1066       }
1067
1068       if ( left1 && right1 )
1069       {
1070         if ( left1->y < left2->y && right1->y > right2->y )
1071           result[i] = FT_ORIENTATION_TRUETYPE;
1072         else if ( left1->y > left2->y && right1->y < right2->y )
1073           result[i] = FT_ORIENTATION_POSTSCRIPT;
1074         else
1075           result[i] = FT_ORIENTATION_NONE;
1076       }
1077     }
1078
1079     if ( result[0] != FT_ORIENTATION_NONE                     &&
1080          ( result[0] == result[1] || result[0] == result[2] ) )
1081       return result[0];
1082
1083     if ( result[1] != FT_ORIENTATION_NONE && result[1] == result[2] )
1084       return result[1];
1085
1086     return FT_ORIENTATION_TRUETYPE;
1087   }
1088
1089
1090 /* END */