src/autofit/afloader.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  afloader.c                                                             */
   4 /*                                                                         */
   5 /*    Auto-fitter glyph loading routines (body).                           */
   6 /*                                                                         */
   7 /*  Copyright 2003-2009, 2011-2014 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 #include "afglobal.h"
  20 #include "afloader.h"
  21 #include "afhints.h"
  22 #include "aferrors.h"
  23 #include "afmodule.h"
  24 #include "afpic.h"
  25
  26
  27   /* Initialize glyph loader. */
  28
  29   FT_LOCAL_DEF( FT_Error )
  30   af_loader_init( AF_Module  module )
  31   {
  32     AF_Loader  loader = module->loader;
  33     FT_Memory  memory = module->root.library->memory;
  34
  35
  36     FT_ZERO( loader );
  37
  38     af_glyph_hints_init( &loader->hints, memory );
  39 #ifdef FT_DEBUG_AUTOFIT
  40     _af_debug_hints = &loader->hints;
  41 #endif
  42     return FT_GlyphLoader_New( memory, &loader->gloader );
  43   }
  44
  45
  46   /* Reset glyph loader and compute globals if necessary. */
  47
  48   FT_LOCAL_DEF( FT_Error )
  49   af_loader_reset( AF_Module  module,
  50                    FT_Face    face )
  51   {
  52     FT_Error   error  = FT_Err_Ok;
  53     AF_Loader  loader = module->loader;
  54
  55
  56     loader->face    = face;
  57     loader->globals = (AF_FaceGlobals)face->autohint.data;
  58
  59     FT_GlyphLoader_Rewind( loader->gloader );
  60
  61     if ( loader->globals == NULL )
  62     {
  63       error = af_face_globals_new( face, &loader->globals, module );
  64       if ( !error )
  65       {
  66         face->autohint.data =
  67           (FT_Pointer)loader->globals;
  68         face->autohint.finalizer =
  69           (FT_Generic_Finalizer)af_face_globals_free;
  70       }
  71     }
  72
  73     return error;
  74   }
  75
  76
  77   /* Finalize glyph loader. */
  78
  79   FT_LOCAL_DEF( void )
  80   af_loader_done( AF_Module  module )
  81   {
  82     AF_Loader  loader = module->loader;
  83
  84
  85     af_glyph_hints_done( &loader->hints );
  86
  87     loader->face    = NULL;
  88     loader->globals = NULL;
  89
  90 #ifdef FT_DEBUG_AUTOFIT
  91     _af_debug_hints = NULL;
  92 #endif
  93     FT_GlyphLoader_Done( loader->gloader );
  94     loader->gloader = NULL;
  95   }
  96
  97
  98   /* Load a single glyph component.  This routine calls itself */
  99   /* recursively, if necessary, and does the main work of      */
 100   /* `af_loader_load_glyph.'                                   */
 101
 102   static FT_Error
 103   af_loader_load_g( AF_Loader  loader,
 104                     AF_Scaler  scaler,
 105                     FT_UInt    glyph_index,
 106                     FT_Int32   load_flags,
 107                     FT_UInt    depth )
 108   {
 109     FT_Error          error;
 110     FT_Face           face     = loader->face;
 111     FT_GlyphLoader    gloader  = loader->gloader;
 112     AF_StyleMetrics   metrics  = loader->metrics;
 113     AF_GlyphHints     hints    = &loader->hints;
 114     FT_GlyphSlot      slot     = face->glyph;
 115     FT_Slot_Internal  internal = slot->internal;
 116     FT_Int32          flags;
 117
 118
 119     flags = load_flags | FT_LOAD_LINEAR_DESIGN;
 120     error = FT_Load_Glyph( face, glyph_index, flags );
 121     if ( error )
 122       goto Exit;
 123
 124     loader->transformed = internal->glyph_transformed;
 125     if ( loader->transformed )
 126     {
 127       FT_Matrix  inverse;
 128
 129
 130       loader->trans_matrix = internal->glyph_matrix;
 131       loader->trans_delta  = internal->glyph_delta;
 132
 133       inverse = loader->trans_matrix;
 134       if ( !FT_Matrix_Invert( &inverse ) )
 135         FT_Vector_Transform( &loader->trans_delta, &inverse );
 136     }
 137
 138     switch ( slot->format )
 139     {
 140     case FT_GLYPH_FORMAT_OUTLINE:
 141       /* translate the loaded glyph when an internal transform is needed */
 142       if ( loader->transformed )
 143         FT_Outline_Translate( &slot->outline,
 144                               loader->trans_delta.x,
 145                               loader->trans_delta.y );
 146
 147       /* copy the outline points in the loader's current                */
 148       /* extra points which are used to keep original glyph coordinates */
 149       error = FT_GLYPHLOADER_CHECK_POINTS( gloader,
 150                                            slot->outline.n_points + 4,
 151                                            slot->outline.n_contours );
 152       if ( error )
 153         goto Exit;
 154
 155       FT_ARRAY_COPY( gloader->current.outline.points,
 156                      slot->outline.points,
 157                      slot->outline.n_points );
 158
 159       FT_ARRAY_COPY( gloader->current.outline.contours,
 160                      slot->outline.contours,
 161                      slot->outline.n_contours );
 162
 163       FT_ARRAY_COPY( gloader->current.outline.tags,
 164                      slot->outline.tags,
 165                      slot->outline.n_points );
 166
 167       gloader->current.outline.n_points   = slot->outline.n_points;
 168       gloader->current.outline.n_contours = slot->outline.n_contours;
 169
 170       /* compute original horizontal phantom points (and ignore */
 171       /* vertical ones)                                         */
 172       loader->pp1.x = hints->x_delta;
 173       loader->pp1.y = hints->y_delta;
 174       loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
 175                                  hints->x_scale ) + hints->x_delta;
 176       loader->pp2.y = hints->y_delta;
 177
 178       /* be sure to check for spacing glyphs */
 179       if ( slot->outline.n_points == 0 )
 180         goto Hint_Metrics;
 181
 182       /* now load the slot image into the auto-outline and run the */
 183       /* automatic hinting process                                 */
 184       {
 185 #ifdef FT_CONFIG_OPTION_PIC
 186         AF_FaceGlobals         globals = loader->globals;
 187 #endif
 188         AF_StyleClass          style_class = metrics->style_class;
 189         AF_WritingSystemClass  writing_system_class =
 190           AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
 191
 192
 193         if ( writing_system_class->style_hints_apply )
 194           writing_system_class->style_hints_apply( hints,
 195                                                    &gloader->current.outline,
 196                                                    metrics );
 197       }
 198
 199       /* we now need to adjust the metrics according to the change in */
 200       /* width/positioning that occurred during the hinting process   */
 201       if ( scaler->render_mode != FT_RENDER_MODE_LIGHT )
 202       {
 203         FT_Pos        old_rsb, old_lsb, new_lsb;
 204         FT_Pos        pp1x_uh, pp2x_uh;
 205         AF_AxisHints  axis  = &hints->axis[AF_DIMENSION_HORZ];
 206         AF_Edge       edge1 = axis->edges;         /* leftmost edge  */
 207         AF_Edge       edge2 = edge1 +
 208                               axis->num_edges - 1; /* rightmost edge */
 209
 210
 211         if ( axis->num_edges > 1 && AF_HINTS_DO_ADVANCE( hints ) )
 212         {
 213           old_rsb = loader->pp2.x - edge2->opos;
 214           old_lsb = edge1->opos;
 215           new_lsb = edge1->pos;
 216
 217           /* remember unhinted values to later account */
 218           /* for rounding errors                       */
 219
 220           pp1x_uh = new_lsb    - old_lsb;
 221           pp2x_uh = edge2->pos + old_rsb;
 222
 223           /* prefer too much space over too little space */
 224           /* for very small sizes                        */
 225
 226           if ( old_lsb < 24 )
 227             pp1x_uh -= 8;
 228
 229           if ( old_rsb < 24 )
 230             pp2x_uh += 8;
 231
 232           loader->pp1.x = FT_PIX_ROUND( pp1x_uh );
 233           loader->pp2.x = FT_PIX_ROUND( pp2x_uh );
 234
 235           if ( loader->pp1.x >= new_lsb && old_lsb > 0 )
 236             loader->pp1.x -= 64;
 237
 238           if ( loader->pp2.x <= edge2->pos && old_rsb > 0 )
 239             loader->pp2.x += 64;
 240
 241           slot->lsb_delta = loader->pp1.x - pp1x_uh;
 242           slot->rsb_delta = loader->pp2.x - pp2x_uh;
 243         }
 244         else
 245         {
 246           FT_Pos  pp1x = loader->pp1.x;
 247           FT_Pos  pp2x = loader->pp2.x;
 248
 249
 250           loader->pp1.x = FT_PIX_ROUND( pp1x );
 251           loader->pp2.x = FT_PIX_ROUND( pp2x );
 252
 253           slot->lsb_delta = loader->pp1.x - pp1x;
 254           slot->rsb_delta = loader->pp2.x - pp2x;
 255         }
 256       }
 257       else
 258       {
 259         FT_Pos  pp1x = loader->pp1.x;
 260         FT_Pos  pp2x = loader->pp2.x;
 261
 262
 263         loader->pp1.x = FT_PIX_ROUND( pp1x + hints->xmin_delta );
 264         loader->pp2.x = FT_PIX_ROUND( pp2x + hints->xmax_delta );
 265
 266         slot->lsb_delta = loader->pp1.x - pp1x;
 267         slot->rsb_delta = loader->pp2.x - pp2x;
 268       }
 269
 270       /* good, we simply add the glyph to our loader's base */
 271       FT_GlyphLoader_Add( gloader );
 272       break;
 273
 274     case FT_GLYPH_FORMAT_COMPOSITE:
 275       {
 276         FT_UInt      nn, num_subglyphs = slot->num_subglyphs;
 277         FT_UInt      num_base_subgs, start_point;
 278         FT_SubGlyph  subglyph;
 279
 280
 281         start_point = gloader->base.outline.n_points;
 282
 283         /* first of all, copy the subglyph descriptors in the glyph loader */
 284         error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs );
 285         if ( error )
 286           goto Exit;
 287
 288         FT_ARRAY_COPY( gloader->current.subglyphs,
 289                        slot->subglyphs,
 290                        num_subglyphs );
 291
 292         gloader->current.num_subglyphs = num_subglyphs;
 293         num_base_subgs                 = gloader->base.num_subglyphs;
 294
 295         /* now read each subglyph independently */
 296         for ( nn = 0; nn < num_subglyphs; nn++ )
 297         {
 298           FT_Vector  pp1, pp2;
 299           FT_Pos     x, y;
 300           FT_UInt    num_points, num_new_points, num_base_points;
 301
 302
 303           /* gloader.current.subglyphs can change during glyph loading due */
 304           /* to re-allocation -- we must recompute the current subglyph on */
 305           /* each iteration                                                */
 306           subglyph = gloader->base.subglyphs + num_base_subgs + nn;
 307
 308           pp1 = loader->pp1;
 309           pp2 = loader->pp2;
 310
 311           num_base_points = gloader->base.outline.n_points;
 312
 313           error = af_loader_load_g( loader, scaler, subglyph->index,
 314                                     load_flags, depth + 1 );
 315           if ( error )
 316             goto Exit;
 317
 318           /* recompute subglyph pointer */
 319           subglyph = gloader->base.subglyphs + num_base_subgs + nn;
 320
 321           if ( !( subglyph->flags & FT_SUBGLYPH_FLAG_USE_MY_METRICS ) )
 322           {
 323             loader->pp1 = pp1;
 324             loader->pp2 = pp2;
 325           }
 326
 327           num_points     = gloader->base.outline.n_points;
 328           num_new_points = num_points - num_base_points;
 329
 330           /* now perform the transformation required for this subglyph */
 331
 332           if ( subglyph->flags & ( FT_SUBGLYPH_FLAG_SCALE    |
 333                                    FT_SUBGLYPH_FLAG_XY_SCALE |
 334                                    FT_SUBGLYPH_FLAG_2X2      ) )
 335           {
 336             FT_Vector*  cur   = gloader->base.outline.points +
 337                                 num_base_points;
 338             FT_Vector*  limit = cur + num_new_points;
 339
 340
 341             for ( ; cur < limit; cur++ )
 342               FT_Vector_Transform( cur, &subglyph->transform );
 343           }
 344
 345           /* apply offset */
 346
 347           if ( !( subglyph->flags & FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES ) )
 348           {
 349             FT_Int      k = subglyph->arg1;
 350             FT_UInt     l = subglyph->arg2;
 351             FT_Vector*  p1;
 352             FT_Vector*  p2;
 353
 354
 355             if ( start_point + k >= num_base_points         ||
 356                                l >= (FT_UInt)num_new_points )
 357             {
 358               error = FT_THROW( Invalid_Composite );
 359               goto Exit;
 360             }
 361
 362             l += num_base_points;
 363
 364             /* for now, only use the current point coordinates; */
 365             /* we eventually may consider another approach      */
 366             p1 = gloader->base.outline.points + start_point + k;
 367             p2 = gloader->base.outline.points + start_point + l;
 368
 369             x = p1->x - p2->x;
 370             y = p1->y - p2->y;
 371           }
 372           else
 373           {
 374             x = FT_MulFix( subglyph->arg1, hints->x_scale ) + hints->x_delta;
 375             y = FT_MulFix( subglyph->arg2, hints->y_scale ) + hints->y_delta;
 376
 377             x = FT_PIX_ROUND( x );
 378             y = FT_PIX_ROUND( y );
 379           }
 380
 381           {
 382             FT_Outline  dummy = gloader->base.outline;
 383
 384
 385             dummy.points  += num_base_points;
 386             dummy.n_points = (short)num_new_points;
 387
 388             FT_Outline_Translate( &dummy, x, y );
 389           }
 390         }
 391       }
 392       break;
 393
 394     default:
 395       /* we don't support other formats (yet?) */
 396       error = FT_THROW( Unimplemented_Feature );
 397     }
 398
 399   Hint_Metrics:
 400     if ( depth == 0 )
 401     {
 402       FT_BBox    bbox;
 403       FT_Vector  vvector;
 404
 405
 406       vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
 407       vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
 408       vvector.x = FT_MulFix( vvector.x, metrics->scaler.x_scale );
 409       vvector.y = FT_MulFix( vvector.y, metrics->scaler.y_scale );
 410
 411       /* transform the hinted outline if needed */
 412       if ( loader->transformed )
 413       {
 414         FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
 415         FT_Vector_Transform( &vvector, &loader->trans_matrix );
 416       }
 417 #if 1
 418       /* we must translate our final outline by -pp1.x and compute */
 419       /* the new metrics                                           */
 420       if ( loader->pp1.x )
 421         FT_Outline_Translate( &gloader->base.outline, -loader->pp1.x, 0 );
 422 #endif
 423       FT_Outline_Get_CBox( &gloader->base.outline, &bbox );
 424
 425       bbox.xMin = FT_PIX_FLOOR( bbox.xMin );
 426       bbox.yMin = FT_PIX_FLOOR( bbox.yMin );
 427       bbox.xMax = FT_PIX_CEIL(  bbox.xMax );
 428       bbox.yMax = FT_PIX_CEIL(  bbox.yMax );
 429
 430       slot->metrics.width        = bbox.xMax - bbox.xMin;
 431       slot->metrics.height       = bbox.yMax - bbox.yMin;
 432       slot->metrics.horiBearingX = bbox.xMin;
 433       slot->metrics.horiBearingY = bbox.yMax;
 434
 435       slot->metrics.vertBearingX = FT_PIX_FLOOR( bbox.xMin + vvector.x );
 436       slot->metrics.vertBearingY = FT_PIX_FLOOR( bbox.yMax + vvector.y );
 437
 438       /* for mono-width fonts (like Andale, Courier, etc.) we need */
 439       /* to keep the original rounded advance width; ditto for     */
 440       /* digits if all have the same advance width                 */
 441 #if 0
 442       if ( !FT_IS_FIXED_WIDTH( slot->face ) )
 443         slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
 444       else
 445         slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
 446                                                x_scale );
 447 #else
 448       if ( scaler->render_mode != FT_RENDER_MODE_LIGHT                      &&
 449            ( FT_IS_FIXED_WIDTH( slot->face )                              ||
 450              ( af_face_globals_is_digit( loader->globals, glyph_index ) &&
 451                metrics->digits_have_same_width                          ) ) )
 452       {
 453         slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
 454                                                metrics->scaler.x_scale );
 455
 456         /* Set delta values to 0.  Otherwise code that uses them is */
 457         /* going to ruin the fixed advance width.                   */
 458         slot->lsb_delta = 0;
 459         slot->rsb_delta = 0;
 460       }
 461       else
 462       {
 463         /* non-spacing glyphs must stay as-is */
 464         if ( slot->metrics.horiAdvance )
 465           slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
 466       }
 467 #endif
 468
 469       slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
 470                                              metrics->scaler.y_scale );
 471
 472       slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );
 473       slot->metrics.vertAdvance = FT_PIX_ROUND( slot->metrics.vertAdvance );
 474
 475       /* now copy outline into glyph slot */
 476       FT_GlyphLoader_Rewind( internal->loader );
 477       error = FT_GlyphLoader_CopyPoints( internal->loader, gloader );
 478       if ( error )
 479         goto Exit;
 480
 481       /* reassign all outline fields except flags to protect them */
 482       slot->outline.n_contours = internal->loader->base.outline.n_contours;
 483       slot->outline.n_points   = internal->loader->base.outline.n_points;
 484       slot->outline.points     = internal->loader->base.outline.points;
 485       slot->outline.tags       = internal->loader->base.outline.tags;
 486       slot->outline.contours   = internal->loader->base.outline.contours;
 487
 488       slot->format  = FT_GLYPH_FORMAT_OUTLINE;
 489     }
 490
 491   Exit:
 492     return error;
 493   }
 494
 495
 496   /* Load a glyph. */
 497
 498   FT_LOCAL_DEF( FT_Error )
 499   af_loader_load_glyph( AF_Module  module,
 500                         FT_Face    face,
 501                         FT_UInt    gindex,
 502                         FT_Int32   load_flags )
 503   {
 504     FT_Error      error;
 505     FT_Size       size   = face->size;
 506     AF_Loader     loader = module->loader;
 507     AF_ScalerRec  scaler;
 508
 509
 510     if ( !size )
 511       return FT_THROW( Invalid_Size_Handle );
 512
 513     FT_ZERO( &scaler );
 514
 515     scaler.face    = face;
 516     scaler.x_scale = size->metrics.x_scale;
 517     scaler.x_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
 518     scaler.y_scale = size->metrics.y_scale;
 519     scaler.y_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
 520
 521     scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
 522     scaler.flags       = 0;  /* XXX: fix this */
 523
 524     error = af_loader_reset( module, face );
 525     if ( !error )
 526     {
 527       AF_StyleMetrics  metrics;
 528       FT_UInt          options = AF_STYLE_NONE_DFLT;
 529
 530
 531 #ifdef FT_OPTION_AUTOFIT2
 532       /* XXX: undocumented hook to activate the latin2 writing system */
 533       if ( load_flags & ( 1UL << 20 ) )
 534         options = AF_STYLE_LTN2_DFLT;
 535 #endif
 536
 537       error = af_face_globals_get_metrics( loader->globals, gindex,
 538                                            options, &metrics );
 539       if ( !error )
 540       {
 541 #ifdef FT_CONFIG_OPTION_PIC
 542         AF_FaceGlobals         globals = loader->globals;
 543 #endif
 544         AF_StyleClass          style_class = metrics->style_class;
 545         AF_WritingSystemClass  writing_system_class =
 546           AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
 547
 548
 549         loader->metrics = metrics;
 550
 551         if ( writing_system_class->style_metrics_scale )
 552           writing_system_class->style_metrics_scale( metrics, &scaler );
 553         else
 554           metrics->scaler = scaler;
 555
 556         load_flags |=  FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_TRANSFORM;
 557         load_flags &= ~FT_LOAD_RENDER;
 558
 559         if ( writing_system_class->style_hints_init )
 560         {
 561           error = writing_system_class->style_hints_init( &loader->hints,
 562                                                           metrics );
 563           if ( error )
 564             goto Exit;
 565         }
 566
 567         error = af_loader_load_g( loader, &scaler, gindex, load_flags, 0 );
 568       }
 569     }
 570   Exit:
 571     return error;
 572   }
 573
 574
 575 /* END */