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/src/compiler/android-ndk/jni/freetype/src/autofit/aflatin2.c

http://ftk.googlecode.com/
C | 2219 lines | 1493 code | 457 blank | 269 comment | 377 complexity | 0a31662f8c7a95080fd23b9882d4941f MD5 | raw file

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   1/***************************************************************************/
   2/*                                                                         */
   3/*  aflatin.c                                                              */
   4/*                                                                         */
   5/*    Auto-fitter hinting routines for latin script (body).                */
   6/*                                                                         */
   7/*  Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009 by                  */
   8/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9/*                                                                         */
  10/*  This file is part of the FreeType project, and may only be used,       */
  11/*  modified, and distributed under the terms of the FreeType project      */
  12/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13/*  this file you indicate that you have read the license and              */
  14/*  understand and accept it fully.                                        */
  15/*                                                                         */
  16/***************************************************************************/
  17
  18
  19#include FT_ADVANCES_H
  20
  21#include "aflatin.h"
  22#include "aflatin2.h"
  23#include "aferrors.h"
  24
  25
  26#ifdef AF_USE_WARPER
  27#include "afwarp.h"
  28#endif
  29
  30  FT_LOCAL_DEF( FT_Error )
  31  af_latin2_hints_compute_segments( AF_GlyphHints  hints,
  32                                   AF_Dimension   dim );
  33
  34  FT_LOCAL_DEF( void )
  35  af_latin2_hints_link_segments( AF_GlyphHints  hints,
  36                                 AF_Dimension   dim );
  37
  38  /*************************************************************************/
  39  /*************************************************************************/
  40  /*****                                                               *****/
  41  /*****            L A T I N   G L O B A L   M E T R I C S            *****/
  42  /*****                                                               *****/
  43  /*************************************************************************/
  44  /*************************************************************************/
  45
  46  FT_LOCAL_DEF( void )
  47  af_latin2_metrics_init_widths( AF_LatinMetrics  metrics,
  48                                FT_Face          face,
  49                                FT_ULong         charcode )
  50  {
  51    /* scan the array of segments in each direction */
  52    AF_GlyphHintsRec  hints[1];
  53
  54
  55    af_glyph_hints_init( hints, face->memory );
  56
  57    metrics->axis[AF_DIMENSION_HORZ].width_count = 0;
  58    metrics->axis[AF_DIMENSION_VERT].width_count = 0;
  59
  60    {
  61      FT_Error             error;
  62      FT_UInt              glyph_index;
  63      int                  dim;
  64      AF_LatinMetricsRec   dummy[1];
  65      AF_Scaler            scaler = &dummy->root.scaler;
  66
  67
  68      glyph_index = FT_Get_Char_Index( face, charcode );
  69      if ( glyph_index == 0 )
  70        goto Exit;
  71
  72      error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
  73      if ( error || face->glyph->outline.n_points <= 0 )
  74        goto Exit;
  75
  76      FT_ZERO( dummy );
  77
  78      dummy->units_per_em = metrics->units_per_em;
  79      scaler->x_scale     = scaler->y_scale = 0x10000L;
  80      scaler->x_delta     = scaler->y_delta = 0;
  81      scaler->face        = face;
  82      scaler->render_mode = FT_RENDER_MODE_NORMAL;
  83      scaler->flags       = 0;
  84
  85      af_glyph_hints_rescale( hints, (AF_ScriptMetrics)dummy );
  86
  87      error = af_glyph_hints_reload( hints, &face->glyph->outline, 0 );
  88      if ( error )
  89        goto Exit;
  90
  91      for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
  92      {
  93        AF_LatinAxis  axis    = &metrics->axis[dim];
  94        AF_AxisHints  axhints = &hints->axis[dim];
  95        AF_Segment    seg, limit, link;
  96        FT_UInt       num_widths = 0;
  97
  98
  99        error = af_latin2_hints_compute_segments( hints,
 100                                                 (AF_Dimension)dim );
 101        if ( error )
 102          goto Exit;
 103
 104        af_latin2_hints_link_segments( hints,
 105                                      (AF_Dimension)dim );
 106
 107        seg   = axhints->segments;
 108        limit = seg + axhints->num_segments;
 109
 110        for ( ; seg < limit; seg++ )
 111        {
 112          link = seg->link;
 113
 114          /* we only consider stem segments there! */
 115          if ( link && link->link == seg && link > seg )
 116          {
 117            FT_Pos  dist;
 118
 119
 120            dist = seg->pos - link->pos;
 121            if ( dist < 0 )
 122              dist = -dist;
 123
 124            if ( num_widths < AF_LATIN_MAX_WIDTHS )
 125              axis->widths[ num_widths++ ].org = dist;
 126          }
 127        }
 128
 129        af_sort_widths( num_widths, axis->widths );
 130        axis->width_count = num_widths;
 131      }
 132
 133  Exit:
 134      for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ )
 135      {
 136        AF_LatinAxis  axis = &metrics->axis[dim];
 137        FT_Pos        stdw;
 138
 139
 140        stdw = ( axis->width_count > 0 )
 141                 ? axis->widths[0].org
 142                 : AF_LATIN_CONSTANT( metrics, 50 );
 143
 144        /* let's try 20% of the smallest width */
 145        axis->edge_distance_threshold = stdw / 5;
 146        axis->standard_width          = stdw;
 147        axis->extra_light             = 0;
 148      }
 149    }
 150
 151    af_glyph_hints_done( hints );
 152  }
 153
 154
 155
 156#define AF_LATIN_MAX_TEST_CHARACTERS  12
 157
 158
 159  static const char af_latin2_blue_chars[AF_LATIN_MAX_BLUES][AF_LATIN_MAX_TEST_CHARACTERS+1] =
 160  {
 161    "THEZOCQS",
 162    "HEZLOCUS",
 163    "fijkdbh",
 164    "xzroesc",
 165    "xzroesc",
 166    "pqgjy"
 167  };
 168
 169
 170  static void
 171  af_latin2_metrics_init_blues( AF_LatinMetrics  metrics,
 172                               FT_Face          face )
 173  {
 174    FT_Pos        flats [AF_LATIN_MAX_TEST_CHARACTERS];
 175    FT_Pos        rounds[AF_LATIN_MAX_TEST_CHARACTERS];
 176    FT_Int        num_flats;
 177    FT_Int        num_rounds;
 178    FT_Int        bb;
 179    AF_LatinBlue  blue;
 180    FT_Error      error;
 181    AF_LatinAxis  axis  = &metrics->axis[AF_DIMENSION_VERT];
 182    FT_GlyphSlot  glyph = face->glyph;
 183
 184
 185    /* we compute the blues simply by loading each character from the    */
 186    /* 'af_latin2_blue_chars[blues]' string, then compute its top-most or */
 187    /* bottom-most points (depending on `AF_IS_TOP_BLUE')                */
 188
 189    AF_LOG(( "blue zones computation\n" ));
 190    AF_LOG(( "------------------------------------------------\n" ));
 191
 192    for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
 193    {
 194      const char*  p     = af_latin2_blue_chars[bb];
 195      const char*  limit = p + AF_LATIN_MAX_TEST_CHARACTERS;
 196      FT_Pos*      blue_ref;
 197      FT_Pos*      blue_shoot;
 198
 199
 200      AF_LOG(( "blue %3d: ", bb ));
 201
 202      num_flats  = 0;
 203      num_rounds = 0;
 204
 205      for ( ; p < limit && *p; p++ )
 206      {
 207        FT_UInt     glyph_index;
 208        FT_Int      best_point, best_y, best_first, best_last;
 209        FT_Vector*  points;
 210        FT_Bool     round;
 211
 212
 213        AF_LOG(( "'%c'", *p ));
 214
 215        /* load the character in the face -- skip unknown or empty ones */
 216        glyph_index = FT_Get_Char_Index( face, (FT_UInt)*p );
 217        if ( glyph_index == 0 )
 218          continue;
 219
 220        error = FT_Load_Glyph( face, glyph_index, FT_LOAD_NO_SCALE );
 221        if ( error || glyph->outline.n_points <= 0 )
 222          continue;
 223
 224        /* now compute min or max point indices and coordinates */
 225        points      = glyph->outline.points;
 226        best_point  = -1;
 227        best_y      = 0;  /* make compiler happy */
 228        best_first  = 0;  /* ditto */
 229        best_last   = 0;  /* ditto */
 230
 231        {
 232          FT_Int  nn;
 233          FT_Int  first = 0;
 234          FT_Int  last  = -1;
 235
 236
 237          for ( nn = 0; nn < glyph->outline.n_contours; first = last+1, nn++ )
 238          {
 239            FT_Int  old_best_point = best_point;
 240            FT_Int  pp;
 241
 242
 243            last = glyph->outline.contours[nn];
 244
 245            /* Avoid single-point contours since they are never rasterized. */
 246            /* In some fonts, they correspond to mark attachment points     */
 247            /* which are way outside of the glyph's real outline.           */
 248            if ( last == first )
 249                continue;
 250
 251            if ( AF_LATIN_IS_TOP_BLUE( bb ) )
 252            {
 253              for ( pp = first; pp <= last; pp++ )
 254                if ( best_point < 0 || points[pp].y > best_y )
 255                {
 256                  best_point = pp;
 257                  best_y     = points[pp].y;
 258                }
 259            }
 260            else
 261            {
 262              for ( pp = first; pp <= last; pp++ )
 263                if ( best_point < 0 || points[pp].y < best_y )
 264                {
 265                  best_point = pp;
 266                  best_y     = points[pp].y;
 267                }
 268            }
 269
 270            if ( best_point != old_best_point )
 271            {
 272              best_first = first;
 273              best_last  = last;
 274            }
 275          }
 276          AF_LOG(( "%5d", best_y ));
 277        }
 278
 279        /* now check whether the point belongs to a straight or round   */
 280        /* segment; we first need to find in which contour the extremum */
 281        /* lies, then inspect its previous and next points              */
 282        {
 283          FT_Int  start, end, prev, next;
 284          FT_Pos  dist;
 285
 286
 287          /* now look for the previous and next points that are not on the */
 288          /* same Y coordinate.  Threshold the `closeness'...              */
 289          start = end = best_point;
 290
 291          do
 292          {
 293            prev = start-1;
 294            if ( prev < best_first )
 295              prev = best_last;
 296
 297            dist = points[prev].y - best_y;
 298            if ( dist < -5 || dist > 5 )
 299              break;
 300
 301            start = prev;
 302
 303          } while ( start != best_point );
 304
 305          do
 306          {
 307            next = end+1;
 308            if ( next > best_last )
 309              next = best_first;
 310
 311            dist = points[next].y - best_y;
 312            if ( dist < -5 || dist > 5 )
 313              break;
 314
 315            end = next;
 316
 317          } while ( end != best_point );
 318
 319          /* now, set the `round' flag depending on the segment's kind */
 320          round = FT_BOOL(
 321            FT_CURVE_TAG( glyph->outline.tags[start] ) != FT_CURVE_TAG_ON ||
 322            FT_CURVE_TAG( glyph->outline.tags[ end ] ) != FT_CURVE_TAG_ON );
 323
 324          AF_LOG(( "%c ", round ? 'r' : 'f' ));
 325        }
 326
 327        if ( round )
 328          rounds[num_rounds++] = best_y;
 329        else
 330          flats[num_flats++]   = best_y;
 331      }
 332
 333      AF_LOG(( "\n" ));
 334
 335      if ( num_flats == 0 && num_rounds == 0 )
 336      {
 337        /*
 338         *  we couldn't find a single glyph to compute this blue zone,
 339         *  we will simply ignore it then
 340         */
 341        AF_LOG(( "empty\n" ));
 342        continue;
 343      }
 344
 345      /* we have computed the contents of the `rounds' and `flats' tables, */
 346      /* now determine the reference and overshoot position of the blue -- */
 347      /* we simply take the median value after a simple sort               */
 348      af_sort_pos( num_rounds, rounds );
 349      af_sort_pos( num_flats,  flats );
 350
 351      blue       = & axis->blues[axis->blue_count];
 352      blue_ref   = & blue->ref.org;
 353      blue_shoot = & blue->shoot.org;
 354
 355      axis->blue_count++;
 356
 357      if ( num_flats == 0 )
 358      {
 359        *blue_ref   =
 360        *blue_shoot = rounds[num_rounds / 2];
 361      }
 362      else if ( num_rounds == 0 )
 363      {
 364        *blue_ref   =
 365        *blue_shoot = flats[num_flats / 2];
 366      }
 367      else
 368      {
 369        *blue_ref   = flats[num_flats / 2];
 370        *blue_shoot = rounds[num_rounds / 2];
 371      }
 372
 373      /* there are sometimes problems: if the overshoot position of top     */
 374      /* zones is under its reference position, or the opposite for bottom  */
 375      /* zones.  We must thus check everything there and correct the errors */
 376      if ( *blue_shoot != *blue_ref )
 377      {
 378        FT_Pos   ref      = *blue_ref;
 379        FT_Pos   shoot    = *blue_shoot;
 380        FT_Bool  over_ref = FT_BOOL( shoot > ref );
 381
 382
 383        if ( AF_LATIN_IS_TOP_BLUE( bb ) ^ over_ref )
 384          *blue_shoot = *blue_ref = ( shoot + ref ) / 2;
 385      }
 386
 387      blue->flags = 0;
 388      if ( AF_LATIN_IS_TOP_BLUE( bb ) )
 389        blue->flags |= AF_LATIN_BLUE_TOP;
 390
 391      /*
 392       * The following flags is used later to adjust the y and x scales
 393       * in order to optimize the pixel grid alignment of the top of small
 394       * letters.
 395       */
 396      if ( bb == AF_LATIN_BLUE_SMALL_TOP )
 397        blue->flags |= AF_LATIN_BLUE_ADJUSTMENT;
 398
 399      AF_LOG(( "-- ref = %ld, shoot = %ld\n", *blue_ref, *blue_shoot ));
 400    }
 401
 402    return;
 403  }
 404
 405
 406  FT_LOCAL_DEF( void )
 407  af_latin2_metrics_check_digits( AF_LatinMetrics  metrics,
 408                                  FT_Face          face )
 409  {
 410    FT_UInt   i;
 411    FT_Bool   started = 0, same_width = 1;
 412    FT_Fixed  advance, old_advance = 0;
 413
 414
 415    /* check whether all ASCII digits have the same advance width; */
 416    /* digit `0' is 0x30 in all supported charmaps                 */
 417    for ( i = 0x30; i <= 0x39; i++ )
 418    {
 419      FT_UInt  glyph_index;
 420
 421
 422      glyph_index = FT_Get_Char_Index( face, i );
 423      if ( glyph_index == 0 )
 424        continue;
 425
 426      if ( FT_Get_Advance( face, glyph_index,
 427                           FT_LOAD_NO_SCALE         |
 428                           FT_LOAD_NO_HINTING       |
 429                           FT_LOAD_IGNORE_TRANSFORM,
 430                           &advance ) )
 431        continue;
 432
 433      if ( started )
 434      {
 435        if ( advance != old_advance )
 436        {
 437          same_width = 0;
 438          break;
 439        }
 440      }
 441      else
 442      {
 443        old_advance = advance;
 444        started     = 1;
 445      }
 446    }
 447
 448    metrics->root.digits_have_same_width = same_width;
 449  }
 450
 451
 452  FT_LOCAL_DEF( FT_Error )
 453  af_latin2_metrics_init( AF_LatinMetrics  metrics,
 454                         FT_Face          face )
 455  {
 456    FT_Error    error = AF_Err_Ok;
 457    FT_CharMap  oldmap = face->charmap;
 458    FT_UInt     ee;
 459
 460    static const FT_Encoding  latin_encodings[] =
 461    {
 462      FT_ENCODING_UNICODE,
 463      FT_ENCODING_APPLE_ROMAN,
 464      FT_ENCODING_ADOBE_STANDARD,
 465      FT_ENCODING_ADOBE_LATIN_1,
 466      FT_ENCODING_NONE  /* end of list */
 467    };
 468
 469
 470    metrics->units_per_em = face->units_per_EM;
 471
 472    /* do we have a latin charmap in there? */
 473    for ( ee = 0; latin_encodings[ee] != FT_ENCODING_NONE; ee++ )
 474    {
 475      error = FT_Select_Charmap( face, latin_encodings[ee] );
 476      if ( !error )
 477        break;
 478    }
 479
 480    if ( !error )
 481    {
 482      /* For now, compute the standard width and height from the `o'. */
 483      af_latin2_metrics_init_widths( metrics, face, 'o' );
 484      af_latin2_metrics_init_blues( metrics, face );
 485      af_latin2_metrics_check_digits( metrics, face );
 486    }
 487
 488    FT_Set_Charmap( face, oldmap );
 489    return AF_Err_Ok;
 490  }
 491
 492
 493  static void
 494  af_latin2_metrics_scale_dim( AF_LatinMetrics  metrics,
 495                              AF_Scaler        scaler,
 496                              AF_Dimension     dim )
 497  {
 498    FT_Fixed      scale;
 499    FT_Pos        delta;
 500    AF_LatinAxis  axis;
 501    FT_UInt       nn;
 502
 503
 504    if ( dim == AF_DIMENSION_HORZ )
 505    {
 506      scale = scaler->x_scale;
 507      delta = scaler->x_delta;
 508    }
 509    else
 510    {
 511      scale = scaler->y_scale;
 512      delta = scaler->y_delta;
 513    }
 514
 515    axis = &metrics->axis[dim];
 516
 517    if ( axis->org_scale == scale && axis->org_delta == delta )
 518      return;
 519
 520    axis->org_scale = scale;
 521    axis->org_delta = delta;
 522
 523    /*
 524     * correct Y scale to optimize the alignment of the top of small
 525     * letters to the pixel grid
 526     */
 527    if ( dim == AF_DIMENSION_VERT )
 528    {
 529      AF_LatinAxis  vaxis = &metrics->axis[AF_DIMENSION_VERT];
 530      AF_LatinBlue  blue = NULL;
 531
 532
 533      for ( nn = 0; nn < vaxis->blue_count; nn++ )
 534      {
 535        if ( vaxis->blues[nn].flags & AF_LATIN_BLUE_ADJUSTMENT )
 536        {
 537          blue = &vaxis->blues[nn];
 538          break;
 539        }
 540      }
 541
 542      if ( blue )
 543      {
 544        FT_Pos  scaled = FT_MulFix( blue->shoot.org, scaler->y_scale );
 545        FT_Pos  fitted = ( scaled + 40 ) & ~63;
 546
 547#if 1
 548        if ( scaled != fitted ) {
 549          scale = FT_MulDiv( scale, fitted, scaled );
 550          AF_LOG(( "== scaled x-top = %.2g  fitted = %.2g, scaling = %.4g\n", scaled/64.0, fitted/64.0, (fitted*1.0)/scaled ));
 551        }
 552#endif
 553      }
 554    }
 555
 556    axis->scale = scale;
 557    axis->delta = delta;
 558
 559    if ( dim == AF_DIMENSION_HORZ )
 560    {
 561      metrics->root.scaler.x_scale = scale;
 562      metrics->root.scaler.x_delta = delta;
 563    }
 564    else
 565    {
 566      metrics->root.scaler.y_scale = scale;
 567      metrics->root.scaler.y_delta = delta;
 568    }
 569
 570    /* scale the standard widths */
 571    for ( nn = 0; nn < axis->width_count; nn++ )
 572    {
 573      AF_Width  width = axis->widths + nn;
 574
 575
 576      width->cur = FT_MulFix( width->org, scale );
 577      width->fit = width->cur;
 578    }
 579
 580    /* an extra-light axis corresponds to a standard width that is */
 581    /* smaller than 0.75 pixels                                    */
 582    axis->extra_light =
 583      (FT_Bool)( FT_MulFix( axis->standard_width, scale ) < 32 + 8 );
 584
 585    if ( dim == AF_DIMENSION_VERT )
 586    {
 587      /* scale the blue zones */
 588      for ( nn = 0; nn < axis->blue_count; nn++ )
 589      {
 590        AF_LatinBlue  blue = &axis->blues[nn];
 591        FT_Pos        dist;
 592
 593
 594        blue->ref.cur   = FT_MulFix( blue->ref.org, scale ) + delta;
 595        blue->ref.fit   = blue->ref.cur;
 596        blue->shoot.cur = FT_MulFix( blue->shoot.org, scale ) + delta;
 597        blue->shoot.fit = blue->shoot.cur;
 598        blue->flags    &= ~AF_LATIN_BLUE_ACTIVE;
 599
 600        /* a blue zone is only active if it is less than 3/4 pixels tall */
 601        dist = FT_MulFix( blue->ref.org - blue->shoot.org, scale );
 602        if ( dist <= 48 && dist >= -48 )
 603        {
 604          FT_Pos  delta1, delta2;
 605
 606          delta1 = blue->shoot.org - blue->ref.org;
 607          delta2 = delta1;
 608          if ( delta1 < 0 )
 609            delta2 = -delta2;
 610
 611          delta2 = FT_MulFix( delta2, scale );
 612
 613          if ( delta2 < 32 )
 614            delta2 = 0;
 615          else if ( delta2 < 64 )
 616            delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & ~31 );
 617          else
 618            delta2 = FT_PIX_ROUND( delta2 );
 619
 620          if ( delta1 < 0 )
 621            delta2 = -delta2;
 622
 623          blue->ref.fit   = FT_PIX_ROUND( blue->ref.cur );
 624          blue->shoot.fit = blue->ref.fit + delta2;
 625
 626          AF_LOG(( ">> activating blue zone %d:  ref.cur=%.2g ref.fit=%.2g shoot.cur=%.2g shoot.fit=%.2g\n",
 627                   nn, blue->ref.cur/64.0, blue->ref.fit/64.0,
 628                   blue->shoot.cur/64.0, blue->shoot.fit/64.0 ));
 629
 630          blue->flags |= AF_LATIN_BLUE_ACTIVE;
 631        }
 632      }
 633    }
 634  }
 635
 636
 637  FT_LOCAL_DEF( void )
 638  af_latin2_metrics_scale( AF_LatinMetrics  metrics,
 639                          AF_Scaler        scaler )
 640  {
 641    metrics->root.scaler.render_mode = scaler->render_mode;
 642    metrics->root.scaler.face        = scaler->face;
 643
 644    af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_HORZ );
 645    af_latin2_metrics_scale_dim( metrics, scaler, AF_DIMENSION_VERT );
 646  }
 647
 648
 649  /*************************************************************************/
 650  /*************************************************************************/
 651  /*****                                                               *****/
 652  /*****           L A T I N   G L Y P H   A N A L Y S I S             *****/
 653  /*****                                                               *****/
 654  /*************************************************************************/
 655  /*************************************************************************/
 656
 657#define  SORT_SEGMENTS
 658
 659  FT_LOCAL_DEF( FT_Error )
 660  af_latin2_hints_compute_segments( AF_GlyphHints  hints,
 661                                   AF_Dimension   dim )
 662  {
 663    AF_AxisHints  axis          = &hints->axis[dim];
 664    FT_Memory     memory        = hints->memory;
 665    FT_Error      error         = AF_Err_Ok;
 666    AF_Segment    segment       = NULL;
 667    AF_SegmentRec seg0;
 668    AF_Point*     contour       = hints->contours;
 669    AF_Point*     contour_limit = contour + hints->num_contours;
 670    AF_Direction  major_dir, segment_dir;
 671
 672
 673    FT_ZERO( &seg0 );
 674    seg0.score = 32000;
 675    seg0.flags = AF_EDGE_NORMAL;
 676
 677    major_dir   = (AF_Direction)FT_ABS( axis->major_dir );
 678    segment_dir = major_dir;
 679
 680    axis->num_segments = 0;
 681
 682    /* set up (u,v) in each point */
 683    if ( dim == AF_DIMENSION_HORZ )
 684    {
 685      AF_Point  point = hints->points;
 686      AF_Point  limit = point + hints->num_points;
 687
 688
 689      for ( ; point < limit; point++ )
 690      {
 691        point->u = point->fx;
 692        point->v = point->fy;
 693      }
 694    }
 695    else
 696    {
 697      AF_Point  point = hints->points;
 698      AF_Point  limit = point + hints->num_points;
 699
 700
 701      for ( ; point < limit; point++ )
 702      {
 703        point->u = point->fy;
 704        point->v = point->fx;
 705      }
 706    }
 707
 708    /* do each contour separately */
 709    for ( ; contour < contour_limit; contour++ )
 710    {
 711      AF_Point  point   =  contour[0];
 712      AF_Point  start   =  point;
 713      AF_Point  last    =  point->prev;
 714
 715
 716      if ( point == last )  /* skip singletons -- just in case */
 717        continue;
 718
 719      /* already on an edge ?, backtrack to find its start */
 720      if ( FT_ABS( point->in_dir ) == major_dir )
 721      {
 722        point = point->prev;
 723
 724        while ( point->in_dir == start->in_dir )
 725          point = point->prev;
 726      }
 727      else  /* otherwise, find first segment start, if any */
 728      {
 729        while ( FT_ABS( point->out_dir ) != major_dir )
 730        {
 731          point = point->next;
 732
 733          if ( point == start )
 734            goto NextContour;
 735        }
 736      }
 737
 738      start = point;
 739
 740      for  (;;)
 741      {
 742        AF_Point  first;
 743        FT_Pos    min_u, min_v, max_u, max_v;
 744
 745        /* we're at the start of a new segment */
 746        FT_ASSERT( FT_ABS( point->out_dir ) == major_dir &&
 747                           point->in_dir != point->out_dir );
 748        first = point;
 749
 750        min_u = max_u = point->u;
 751        min_v = max_v = point->v;
 752
 753        point = point->next;
 754
 755        while ( point->out_dir == first->out_dir )
 756        {
 757          point = point->next;
 758
 759          if ( point->u < min_u )
 760            min_u = point->u;
 761
 762          if ( point->u > max_u )
 763            max_u = point->u;
 764        }
 765
 766        if ( point->v < min_v )
 767          min_v = point->v;
 768
 769        if ( point->v > max_v )
 770          max_v = point->v;
 771
 772        /* record new segment */
 773        error = af_axis_hints_new_segment( axis, memory, &segment );
 774        if ( error )
 775          goto Exit;
 776
 777        segment[0]         = seg0;
 778        segment->dir       = first->out_dir;
 779        segment->first     = first;
 780        segment->last      = point;
 781        segment->contour   = contour;
 782        segment->pos       = (FT_Short)(( min_u + max_u ) >> 1);
 783        segment->min_coord = (FT_Short) min_v;
 784        segment->max_coord = (FT_Short) max_v;
 785        segment->height    = (FT_Short)(max_v - min_v);
 786
 787        /* a segment is round if it doesn't have successive */
 788        /* on-curve points.                                 */
 789        {
 790          AF_Point  pt   = first;
 791          AF_Point  last = point;
 792          AF_Flags  f0   = (AF_Flags)(pt->flags & AF_FLAG_CONTROL);
 793          AF_Flags  f1;
 794
 795
 796          segment->flags &= ~AF_EDGE_ROUND;
 797
 798          for ( ; pt != last; f0 = f1 )
 799          {
 800            pt = pt->next;
 801            f1 = (AF_Flags)(pt->flags & AF_FLAG_CONTROL);
 802
 803            if ( !f0 && !f1 )
 804              break;
 805
 806            if ( pt == last )
 807              segment->flags |= AF_EDGE_ROUND;
 808          }
 809        }
 810
 811       /* this can happen in the case of a degenerate contour
 812        * e.g. a 2-point vertical contour
 813        */
 814        if ( point == start )
 815          break;
 816
 817        /* jump to the start of the next segment, if any */
 818        while ( FT_ABS(point->out_dir) != major_dir )
 819        {
 820          point = point->next;
 821
 822          if ( point == start )
 823            goto NextContour;
 824        }
 825      }
 826
 827    NextContour:
 828      ;
 829    } /* contours */
 830
 831    /* now slightly increase the height of segments when this makes */
 832    /* sense -- this is used to better detect and ignore serifs     */
 833    {
 834      AF_Segment  segments     = axis->segments;
 835      AF_Segment  segments_end = segments + axis->num_segments;
 836
 837
 838      for ( segment = segments; segment < segments_end; segment++ )
 839      {
 840        AF_Point  first   = segment->first;
 841        AF_Point  last    = segment->last;
 842        AF_Point  p;
 843        FT_Pos    first_v = first->v;
 844        FT_Pos    last_v  = last->v;
 845
 846
 847        if ( first == last )
 848          continue;
 849
 850        if ( first_v < last_v )
 851        {
 852          p = first->prev;
 853          if ( p->v < first_v )
 854            segment->height = (FT_Short)( segment->height +
 855                                          ( ( first_v - p->v ) >> 1 ) );
 856
 857          p = last->next;
 858          if ( p->v > last_v )
 859            segment->height = (FT_Short)( segment->height +
 860                                          ( ( p->v - last_v ) >> 1 ) );
 861        }
 862        else
 863        {
 864          p = first->prev;
 865          if ( p->v > first_v )
 866            segment->height = (FT_Short)( segment->height +
 867                                          ( ( p->v - first_v ) >> 1 ) );
 868
 869          p = last->next;
 870          if ( p->v < last_v )
 871            segment->height = (FT_Short)( segment->height +
 872                                          ( ( last_v - p->v ) >> 1 ) );
 873        }
 874      }
 875    }
 876
 877#ifdef AF_SORT_SEGMENTS
 878   /* place all segments with a negative direction to the start
 879    * of the array, used to speed up segment linking later...
 880    */
 881    {
 882      AF_Segment  segments = axis->segments;
 883      FT_UInt     count    = axis->num_segments;
 884      FT_UInt     ii, jj;
 885
 886      for (ii = 0; ii < count; ii++)
 887      {
 888        if ( segments[ii].dir > 0 )
 889        {
 890          for (jj = ii+1; jj < count; jj++)
 891          {
 892            if ( segments[jj].dir < 0 )
 893            {
 894              AF_SegmentRec  tmp;
 895
 896              tmp          = segments[ii];
 897              segments[ii] = segments[jj];
 898              segments[jj] = tmp;
 899
 900              break;
 901            }
 902          }
 903
 904          if ( jj == count )
 905            break;
 906        }
 907      }
 908      axis->mid_segments = ii;
 909    }
 910#endif
 911
 912  Exit:
 913    return error;
 914  }
 915
 916
 917  FT_LOCAL_DEF( void )
 918  af_latin2_hints_link_segments( AF_GlyphHints  hints,
 919                                AF_Dimension   dim )
 920  {
 921    AF_AxisHints  axis          = &hints->axis[dim];
 922    AF_Segment    segments      = axis->segments;
 923    AF_Segment    segment_limit = segments + axis->num_segments;
 924#ifdef AF_SORT_SEGMENTS
 925    AF_Segment    segment_mid   = segments + axis->mid_segments;
 926#endif
 927    FT_Pos        len_threshold, len_score;
 928    AF_Segment    seg1, seg2;
 929
 930
 931    len_threshold = AF_LATIN_CONSTANT( hints->metrics, 8 );
 932    if ( len_threshold == 0 )
 933      len_threshold = 1;
 934
 935    len_score = AF_LATIN_CONSTANT( hints->metrics, 6000 );
 936
 937#ifdef AF_SORT_SEGMENTS
 938    for ( seg1 = segments; seg1 < segment_mid; seg1++ )
 939    {
 940      if ( seg1->dir != axis->major_dir || seg1->first == seg1->last )
 941        continue;
 942
 943      for ( seg2 = segment_mid; seg2 < segment_limit; seg2++ )
 944#else
 945    /* now compare each segment to the others */
 946    for ( seg1 = segments; seg1 < segment_limit; seg1++ )
 947    {
 948      /* the fake segments are introduced to hint the metrics -- */
 949      /* we must never link them to anything                     */
 950      if ( seg1->dir != axis->major_dir || seg1->first == seg1->last )
 951        continue;
 952
 953      for ( seg2 = segments; seg2 < segment_limit; seg2++ )
 954        if ( seg1->dir + seg2->dir == 0 && seg2->pos > seg1->pos )
 955#endif
 956        {
 957          FT_Pos  pos1 = seg1->pos;
 958          FT_Pos  pos2 = seg2->pos;
 959          FT_Pos  dist = pos2 - pos1;
 960
 961
 962          if ( dist < 0 )
 963            continue;
 964
 965          {
 966            FT_Pos  min = seg1->min_coord;
 967            FT_Pos  max = seg1->max_coord;
 968            FT_Pos  len, score;
 969
 970
 971            if ( min < seg2->min_coord )
 972              min = seg2->min_coord;
 973
 974            if ( max > seg2->max_coord )
 975              max = seg2->max_coord;
 976
 977            len = max - min;
 978            if ( len >= len_threshold )
 979            {
 980              score = dist + len_score / len;
 981              if ( score < seg1->score )
 982              {
 983                seg1->score = score;
 984                seg1->link  = seg2;
 985              }
 986
 987              if ( score < seg2->score )
 988              {
 989                seg2->score = score;
 990                seg2->link  = seg1;
 991              }
 992            }
 993          }
 994        }
 995    }
 996#if 0
 997    }
 998#endif
 999
1000    /* now, compute the `serif' segments */
1001    for ( seg1 = segments; seg1 < segment_limit; seg1++ )
1002    {
1003      seg2 = seg1->link;
1004
1005      if ( seg2 )
1006      {
1007        if ( seg2->link != seg1 )
1008        {
1009          seg1->link  = 0;
1010          seg1->serif = seg2->link;
1011        }
1012      }
1013    }
1014  }
1015
1016
1017  FT_LOCAL_DEF( FT_Error )
1018  af_latin2_hints_compute_edges( AF_GlyphHints  hints,
1019                                AF_Dimension   dim )
1020  {
1021    AF_AxisHints  axis   = &hints->axis[dim];
1022    FT_Error      error  = AF_Err_Ok;
1023    FT_Memory     memory = hints->memory;
1024    AF_LatinAxis  laxis  = &((AF_LatinMetrics)hints->metrics)->axis[dim];
1025
1026    AF_Segment    segments      = axis->segments;
1027    AF_Segment    segment_limit = segments + axis->num_segments;
1028    AF_Segment    seg;
1029
1030    AF_Direction  up_dir;
1031    FT_Fixed      scale;
1032    FT_Pos        edge_distance_threshold;
1033    FT_Pos        segment_length_threshold;
1034
1035
1036    axis->num_edges = 0;
1037
1038    scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
1039                                         : hints->y_scale;
1040
1041    up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP
1042                                          : AF_DIR_RIGHT;
1043
1044    /*
1045     *  We want to ignore very small (mostly serif) segments, we do that
1046     *  by ignoring those that whose length is less than a given fraction
1047     *  of the standard width. If there is no standard width, we ignore
1048     *  those that are less than a given size in pixels
1049     *
1050     *  also, unlink serif segments that are linked to segments farther
1051     *  than 50% of the standard width
1052     */
1053    if ( dim == AF_DIMENSION_HORZ )
1054    {
1055      if ( laxis->width_count > 0 )
1056        segment_length_threshold = (laxis->standard_width * 10 ) >> 4;
1057      else
1058        segment_length_threshold = FT_DivFix( 64, hints->y_scale );
1059    }
1060    else
1061      segment_length_threshold = 0;
1062
1063    /*********************************************************************/
1064    /*                                                                   */
1065    /* We will begin by generating a sorted table of edges for the       */
1066    /* current direction.  To do so, we simply scan each segment and try */
1067    /* to find an edge in our table that corresponds to its position.    */
1068    /*                                                                   */
1069    /* If no edge is found, we create and insert a new edge in the       */
1070    /* sorted table.  Otherwise, we simply add the segment to the edge's */
1071    /* list which will be processed in the second step to compute the    */
1072    /* edge's properties.                                                */
1073    /*                                                                   */
1074    /* Note that the edges table is sorted along the segment/edge        */
1075    /* position.                                                         */
1076    /*                                                                   */
1077    /*********************************************************************/
1078
1079    edge_distance_threshold = FT_MulFix( laxis->edge_distance_threshold,
1080                                         scale );
1081    if ( edge_distance_threshold > 64 / 4 )
1082      edge_distance_threshold = 64 / 4;
1083
1084    edge_distance_threshold = FT_DivFix( edge_distance_threshold,
1085                                         scale );
1086
1087    for ( seg = segments; seg < segment_limit; seg++ )
1088    {
1089      AF_Edge  found = 0;
1090      FT_Int   ee;
1091
1092
1093      if ( seg->height < segment_length_threshold )
1094        continue;
1095
1096      /* A special case for serif edges: If they are smaller than */
1097      /* 1.5 pixels we ignore them.                               */
1098      if ( seg->serif )
1099      {
1100        FT_Pos  dist = seg->serif->pos - seg->pos;
1101
1102        if (dist < 0)
1103          dist = -dist;
1104
1105        if (dist >= laxis->standard_width >> 1)
1106        {
1107          /* unlink this serif, it is too distant from its reference stem */
1108          seg->serif = NULL;
1109        }
1110        else if ( 2*seg->height < 3 * segment_length_threshold )
1111          continue;
1112      }
1113
1114      /* look for an edge corresponding to the segment */
1115      for ( ee = 0; ee < axis->num_edges; ee++ )
1116      {
1117        AF_Edge  edge = axis->edges + ee;
1118        FT_Pos   dist;
1119
1120
1121        dist = seg->pos - edge->fpos;
1122        if ( dist < 0 )
1123          dist = -dist;
1124
1125        if ( dist < edge_distance_threshold && edge->dir == seg->dir )
1126        {
1127          found = edge;
1128          break;
1129        }
1130      }
1131
1132      if ( !found )
1133      {
1134        AF_Edge   edge;
1135
1136
1137        /* insert a new edge in the list and */
1138        /* sort according to the position    */
1139        error = af_axis_hints_new_edge( axis, seg->pos, seg->dir, memory, &edge );
1140        if ( error )
1141          goto Exit;
1142
1143        /* add the segment to the new edge's list */
1144        FT_ZERO( edge );
1145
1146        edge->first    = seg;
1147        edge->last     = seg;
1148        edge->fpos     = seg->pos;
1149        edge->dir      = seg->dir;
1150        edge->opos     = edge->pos = FT_MulFix( seg->pos, scale );
1151        seg->edge_next = seg;
1152      }
1153      else
1154      {
1155        /* if an edge was found, simply add the segment to the edge's */
1156        /* list                                                       */
1157        seg->edge_next         = found->first;
1158        found->last->edge_next = seg;
1159        found->last            = seg;
1160      }
1161    }
1162
1163
1164    /*********************************************************************/
1165    /*                                                                   */
1166    /* Good, we will now compute each edge's properties according to     */
1167    /* segments found on its position.  Basically, these are:            */
1168    /*                                                                   */
1169    /*  - edge's main direction                                          */
1170    /*  - stem edge, serif edge or both (which defaults to stem then)    */
1171    /*  - rounded edge, straight or both (which defaults to straight)    */
1172    /*  - link for edge                                                  */
1173    /*                                                                   */
1174    /*********************************************************************/
1175
1176    /* first of all, set the `edge' field in each segment -- this is */
1177    /* required in order to compute edge links                       */
1178
1179    /*
1180     * Note that removing this loop and setting the `edge' field of each
1181     * segment directly in the code above slows down execution speed for
1182     * some reasons on platforms like the Sun.
1183     */
1184    {
1185      AF_Edge  edges      = axis->edges;
1186      AF_Edge  edge_limit = edges + axis->num_edges;
1187      AF_Edge  edge;
1188
1189
1190      for ( edge = edges; edge < edge_limit; edge++ )
1191      {
1192        seg = edge->first;
1193        if ( seg )
1194          do
1195          {
1196            seg->edge = edge;
1197            seg       = seg->edge_next;
1198
1199          } while ( seg != edge->first );
1200      }
1201
1202      /* now, compute each edge properties */
1203      for ( edge = edges; edge < edge_limit; edge++ )
1204      {
1205        FT_Int  is_round    = 0;  /* does it contain round segments?    */
1206        FT_Int  is_straight = 0;  /* does it contain straight segments? */
1207        FT_Pos  ups         = 0;  /* number of upwards segments         */
1208        FT_Pos  downs       = 0;  /* number of downwards segments       */
1209
1210
1211        seg = edge->first;
1212
1213        do
1214        {
1215          FT_Bool  is_serif;
1216
1217
1218          /* check for roundness of segment */
1219          if ( seg->flags & AF_EDGE_ROUND )
1220            is_round++;
1221          else
1222            is_straight++;
1223
1224          /* check for segment direction */
1225          if ( seg->dir == up_dir )
1226            ups   += seg->max_coord-seg->min_coord;
1227          else
1228            downs += seg->max_coord-seg->min_coord;
1229
1230          /* check for links -- if seg->serif is set, then seg->link must */
1231          /* be ignored                                                   */
1232          is_serif = (FT_Bool)( seg->serif               &&
1233                                seg->serif->edge         &&
1234                                seg->serif->edge != edge );
1235
1236          if ( ( seg->link && seg->link->edge != NULL ) || is_serif )
1237          {
1238            AF_Edge     edge2;
1239            AF_Segment  seg2;
1240
1241
1242            edge2 = edge->link;
1243            seg2  = seg->link;
1244
1245            if ( is_serif )
1246            {
1247              seg2  = seg->serif;
1248              edge2 = edge->serif;
1249            }
1250
1251            if ( edge2 )
1252            {
1253              FT_Pos  edge_delta;
1254              FT_Pos  seg_delta;
1255
1256
1257              edge_delta = edge->fpos - edge2->fpos;
1258              if ( edge_delta < 0 )
1259                edge_delta = -edge_delta;
1260
1261              seg_delta = seg->pos - seg2->pos;
1262              if ( seg_delta < 0 )
1263                seg_delta = -seg_delta;
1264
1265              if ( seg_delta < edge_delta )
1266                edge2 = seg2->edge;
1267            }
1268            else
1269              edge2 = seg2->edge;
1270
1271            if ( is_serif )
1272            {
1273              edge->serif   = edge2;
1274              edge2->flags |= AF_EDGE_SERIF;
1275            }
1276            else
1277              edge->link  = edge2;
1278          }
1279
1280          seg = seg->edge_next;
1281
1282        } while ( seg != edge->first );
1283
1284        /* set the round/straight flags */
1285        edge->flags = AF_EDGE_NORMAL;
1286
1287        if ( is_round > 0 && is_round >= is_straight )
1288          edge->flags |= AF_EDGE_ROUND;
1289
1290#if 0
1291        /* set the edge's main direction */
1292        edge->dir = AF_DIR_NONE;
1293
1294        if ( ups > downs )
1295          edge->dir = (FT_Char)up_dir;
1296
1297        else if ( ups < downs )
1298          edge->dir = (FT_Char)-up_dir;
1299
1300        else if ( ups == downs )
1301          edge->dir = 0;  /* both up and down! */
1302#endif
1303
1304        /* gets rid of serifs if link is set                */
1305        /* XXX: This gets rid of many unpleasant artefacts! */
1306        /*      Example: the `c' in cour.pfa at size 13     */
1307
1308        if ( edge->serif && edge->link )
1309          edge->serif = 0;
1310      }
1311    }
1312
1313  Exit:
1314    return error;
1315  }
1316
1317
1318  FT_LOCAL_DEF( FT_Error )
1319  af_latin2_hints_detect_features( AF_GlyphHints  hints,
1320                                  AF_Dimension   dim )
1321  {
1322    FT_Error  error;
1323
1324
1325    error = af_latin2_hints_compute_segments( hints, dim );
1326    if ( !error )
1327    {
1328      af_latin2_hints_link_segments( hints, dim );
1329
1330      error = af_latin2_hints_compute_edges( hints, dim );
1331    }
1332    return error;
1333  }
1334
1335
1336  FT_LOCAL_DEF( void )
1337  af_latin2_hints_compute_blue_edges( AF_GlyphHints    hints,
1338                                     AF_LatinMetrics  metrics )
1339  {
1340    AF_AxisHints  axis       = &hints->axis[ AF_DIMENSION_VERT ];
1341    AF_Edge       edge       = axis->edges;
1342    AF_Edge       edge_limit = edge + axis->num_edges;
1343    AF_LatinAxis  latin      = &metrics->axis[ AF_DIMENSION_VERT ];
1344    FT_Fixed      scale      = latin->scale;
1345    FT_Pos        best_dist0;  /* initial threshold */
1346
1347
1348    /* compute the initial threshold as a fraction of the EM size */
1349    best_dist0 = FT_MulFix( metrics->units_per_em / 40, scale );
1350
1351    if ( best_dist0 > 64 / 2 )
1352      best_dist0 = 64 / 2;
1353
1354    /* compute which blue zones are active, i.e. have their scaled */
1355    /* size < 3/4 pixels                                           */
1356
1357    /* for each horizontal edge search the blue zone which is closest */
1358    for ( ; edge < edge_limit; edge++ )
1359    {
1360      FT_Int    bb;
1361      AF_Width  best_blue = NULL;
1362      FT_Pos    best_dist = best_dist0;
1363
1364      for ( bb = 0; bb < AF_LATIN_BLUE_MAX; bb++ )
1365      {
1366        AF_LatinBlue  blue = latin->blues + bb;
1367        FT_Bool       is_top_blue, is_major_dir;
1368
1369
1370        /* skip inactive blue zones (i.e., those that are too small) */
1371        if ( !( blue->flags & AF_LATIN_BLUE_ACTIVE ) )
1372          continue;
1373
1374        /* if it is a top zone, check for right edges -- if it is a bottom */
1375        /* zone, check for left edges                                      */
1376        /*                                                                 */
1377        /* of course, that's for TrueType                                  */
1378        is_top_blue  = (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 );
1379        is_major_dir = FT_BOOL( edge->dir == axis->major_dir );
1380
1381        /* if it is a top zone, the edge must be against the major    */
1382        /* direction; if it is a bottom zone, it must be in the major */
1383        /* direction                                                  */
1384        if ( is_top_blue ^ is_major_dir )
1385        {
1386          FT_Pos     dist;
1387          AF_Width   compare;
1388
1389
1390          /* if it's a rounded edge, compare it to the overshoot position */
1391          /* if it's a flat edge, compare it to the reference position    */
1392          if ( edge->flags & AF_EDGE_ROUND )
1393            compare = &blue->shoot;
1394          else
1395            compare = &blue->ref;
1396
1397          dist = edge->fpos - compare->org;
1398          if (dist < 0)
1399            dist = -dist;
1400
1401          dist = FT_MulFix( dist, scale );
1402          if ( dist < best_dist )
1403          {
1404            best_dist = dist;
1405            best_blue = compare;
1406          }
1407
1408#if 0
1409          /* now, compare it to the overshoot position if the edge is     */
1410          /* rounded, and if the edge is over the reference position of a */
1411          /* top zone, or under the reference position of a bottom zone   */
1412          if ( edge->flags & AF_EDGE_ROUND && dist != 0 )
1413          {
1414            FT_Bool  is_under_ref = FT_BOOL( edge->fpos < blue->ref.org );
1415
1416
1417            if ( is_top_blue ^ is_under_ref )
1418            {
1419              blue = latin->blues + bb;
1420              dist = edge->fpos - blue->shoot.org;
1421              if ( dist < 0 )
1422                dist = -dist;
1423
1424              dist = FT_MulFix( dist, scale );
1425              if ( dist < best_dist )
1426              {
1427                best_dist = dist;
1428                best_blue = & blue->shoot;
1429              }
1430            }
1431          }
1432#endif
1433        }
1434      }
1435
1436      if ( best_blue )
1437        edge->blue_edge = best_blue;
1438    }
1439  }
1440
1441
1442  static FT_Error
1443  af_latin2_hints_init( AF_GlyphHints    hints,
1444                       AF_LatinMetrics  metrics )
1445  {
1446    FT_Render_Mode  mode;
1447    FT_UInt32       scaler_flags, other_flags;
1448    FT_Face         face = metrics->root.scaler.face;
1449
1450
1451    af_glyph_hints_rescale( hints, (AF_ScriptMetrics)metrics );
1452
1453    /*
1454     *  correct x_scale and y_scale if needed, since they may have
1455     *  been modified `af_latin2_metrics_scale_dim' above
1456     */
1457    hints->x_scale = metrics->axis[AF_DIMENSION_HORZ].scale;
1458    hints->x_delta = metrics->axis[AF_DIMENSION_HORZ].delta;
1459    hints->y_scale = metrics->axis[AF_DIMENSION_VERT].scale;
1460    hints->y_delta = metrics->axis[AF_DIMENSION_VERT].delta;
1461
1462    /* compute flags depending on render mode, etc. */
1463    mode = metrics->root.scaler.render_mode;
1464
1465#if 0 /* #ifdef AF_USE_WARPER */
1466    if ( mode == FT_RENDER_MODE_LCD || mode == FT_RENDER_MODE_LCD_V )
1467    {
1468      metrics->root.scaler.render_mode = mode = FT_RENDER_MODE_NORMAL;
1469    }
1470#endif
1471
1472    scaler_flags = hints->scaler_flags;
1473    other_flags  = 0;
1474
1475    /*
1476     *  We snap the width of vertical stems for the monochrome and
1477     *  horizontal LCD rendering targets only.
1478     */
1479    if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD )
1480      other_flags |= AF_LATIN_HINTS_HORZ_SNAP;
1481
1482    /*
1483     *  We snap the width of horizontal stems for the monochrome and
1484     *  vertical LCD rendering targets only.
1485     */
1486    if ( mode == FT_RENDER_MODE_MONO || mode == FT_RENDER_MODE_LCD_V )
1487      other_flags |= AF_LATIN_HINTS_VERT_SNAP;
1488
1489    /*
1490     *  We adjust stems to full pixels only if we don't use the `light' mode.
1491     */
1492    if ( mode != FT_RENDER_MODE_LIGHT )
1493      other_flags |= AF_LATIN_HINTS_STEM_ADJUST;
1494
1495    if ( mode == FT_RENDER_MODE_MONO )
1496      other_flags |= AF_LATIN_HINTS_MONO;
1497
1498    /*
1499     *  In `light' hinting mode we disable horizontal hinting completely.
1500     *  We also do it if the face is italic.
1501     */
1502    if ( mode == FT_RENDER_MODE_LIGHT                    ||
1503         (face->style_flags & FT_STYLE_FLAG_ITALIC) != 0 )
1504      scaler_flags |= AF_SCALER_FLAG_NO_HORIZONTAL;
1505
1506    hints->scaler_flags = scaler_flags;
1507    hints->other_flags  = other_flags;
1508
1509    return 0;
1510  }
1511
1512
1513  /*************************************************************************/
1514  /*************************************************************************/
1515  /*****                                                               *****/
1516  /*****        L A T I N   G L Y P H   G R I D - F I T T I N G        *****/
1517  /*****                                                               *****/
1518  /*************************************************************************/
1519  /*************************************************************************/
1520
1521  /* snap a given width in scaled coordinates to one of the */
1522  /* current standard widths                                */
1523
1524  static FT_Pos
1525  af_latin2_snap_width( AF_Width  widths,
1526                       FT_Int    count,
1527                       FT_Pos    width )
1528  {
1529    int     n;
1530    FT_Pos  best      = 64 + 32 + 2;
1531    FT_Pos  reference = width;
1532    FT_Pos  scaled;
1533
1534
1535    for ( n = 0; n < count; n++ )
1536    {
1537      FT_Pos  w;
1538      FT_Pos  dist;
1539
1540
1541      w = widths[n].cur;
1542      dist = width - w;
1543      if ( dist < 0 )
1544        dist = -dist;
1545      if ( dist < best )
1546      {
1547        best      = dist;
1548        reference = w;
1549      }
1550    }
1551
1552    scaled = FT_PIX_ROUND( reference );
1553
1554    if ( width >= reference )
1555    {
1556      if ( width < scaled + 48 )
1557        width = reference;
1558    }
1559    else
1560    {
1561      if ( width > scaled - 48 )
1562        width = reference;
1563    }
1564
1565    return width;
1566  }
1567
1568
1569  /* compute the snapped width of a given stem */
1570
1571  static FT_Pos
1572  af_latin2_compute_stem_width( AF_GlyphHints  hints,
1573                               AF_Dimension   dim,
1574                               FT_Pos         width,
1575                               AF_Edge_Flags  base_flags,
1576                               AF_Edge_Flags  stem_flags )
1577  {
1578    AF_LatinMetrics  metrics  = (AF_LatinMetrics) hints->metrics;
1579    AF_LatinAxis     axis     = & metrics->axis[dim];
1580    FT_Pos           dist     = width;
1581    FT_Int           sign     = 0;
1582    FT_Int           vertical = ( dim == AF_DIMENSION_VERT );
1583
1584
1585    FT_UNUSED(base_flags);
1586
1587    if ( !AF_LATIN_HINTS_DO_STEM_ADJUST( hints ) ||
1588          axis->extra_light                      )
1589      return width;
1590
1591    if ( dist < 0 )
1592    {
1593      dist = -width;
1594      sign = 1;
1595    }
1596
1597    if ( (  vertical && !AF_LATIN_HINTS_DO_VERT_SNAP( hints ) ) ||
1598         ( !vertical && !AF_LATIN_HINTS_DO_HORZ_SNAP( hints ) ) )
1599    {
1600      /* smooth hinting process: very lightly quantize the stem width */
1601
1602      /* leave the widths of serifs alone */
1603
1604      if ( ( stem_flags & AF_EDGE_SERIF ) && vertical && ( dist < 3 * 64 ) )
1605        goto Done_Width;
1606
1607#if 0
1608      else if ( ( base_flags & AF_EDGE_ROUND ) )
1609      {
1610        if ( dist < 80 )
1611          dist = 64;
1612      }
1613      else if ( dist < 56 )
1614        dist = 56;
1615#endif
1616      if ( axis->width_count > 0 )
1617      {
1618        FT_Pos  delta;
1619
1620
1621        /* compare to standard width */
1622        if ( axis->width_count > 0 )
1623        {
1624          delta = dist - axis->widths[0].cur;
1625
1626          if ( delta < 0 )
1627            delta = -delta;
1628
1629          if ( delta < 40 )
1630          {
1631            dist = axis->widths[0].cur;
1632            if ( dist < 48 )
1633              dist = 48;
1634
1635            goto Done_Width;
1636          }
1637        }
1638
1639        if ( dist < 3 * 64 )
1640        {
1641          delta  = dist & 63;
1642          dist  &= -64;
1643
1644          if ( delta < 10 )
1645            dist += delta;
1646
1647          else if ( delta < 32 )
1648            dist += 10;
1649
1650          else if ( delta < 54 )
1651            dist += 54;
1652
1653          else
1654            dist += delta;
1655        }
1656        else
1657          dist = ( dist + 32 ) & ~63;
1658      }
1659    }
1660    else
1661    {
1662      /* strong hinting process: snap the stem width to integer pixels */
1663      FT_Pos  org_dist = dist;
1664
1665
1666      dist = af_latin2_snap_width( axis->widths, axis->width_count, dist );
1667
1668      if ( vertical )
1669      {
1670        /* in the case of vertical hinting, always round */
1671        /* the stem heights to integer pixels            */
1672
1673        if ( dist >= 64 )
1674          dist = ( dist + 16 ) & ~63;
1675        else
1676          dist = 64;
1677      }
1678      else
1679      {
1680        if ( AF_LATIN_HINTS_DO_MONO( hints ) )
1681        {
1682          /* monochrome horizontal hinting: snap widths to integer pixels */
1683          /* with a different threshold                                   */
1684
1685          if ( dist < 64 )
1686            dist = 64;
1687          else
1688            dist = ( dist + 32 ) & ~63;
1689        }
1690        else
1691        {
1692          /* for horizontal anti-aliased hinting, we adopt a more subtle */
1693          /* approach: we strengthen small stems, round stems whose size */
1694          /* is between 1 and 2 pixels to an integer, otherwise nothing  */
1695
1696          if ( dist < 48 )
1697            dist = ( dist + 64 ) >> 1;
1698
1699          else if ( dist < 128 )
1700          {
1701            /* We only round to an integer width if the corresponding */
1702            /* distortion is less than 1/4 pixel.  Otherwise this     */
1703            /* makes everything worse since the diagonals, which are  */
1704            /* not hinted, appear a lot bolder or thinner than the    */
1705            /* vertical stems.                                        */
1706
1707            FT_Int  delta;
1708
1709
1710            dist = ( dist + 22 ) & ~63;
1711            delta = dist - org_dist

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