src/autofit/afloader.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  afloader.c                                                             */
   4 /*                                                                         */
   5 /*    Auto-fitter glyph loading routines (body).                           */
   6 /*                                                                         */
   7 /*  Copyright 2003-2009, 2011-2012 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 "afloader.h"
  20 #include "afhints.h"
  21 #include "afglobal.h"
  22 #include "aferrors.h"
  23
  24
  25   /* Initialize glyph loader. */
  26
  27   FT_LOCAL_DEF( FT_Error )
  28   af_loader_init( AF_Loader  loader,
  29                   FT_Memory  memory )
  30   {
  31     FT_ZERO( loader );
  32
  33     af_glyph_hints_init( &loader->hints, memory );
  34 #ifdef FT_DEBUG_AUTOFIT
  35     _af_debug_hints = &loader->hints;
  36 #endif
  37     return FT_GlyphLoader_New( memory, &loader->gloader );
  38   }
  39
  40
  41   /* Reset glyph loader and compute globals if necessary. */
  42
  43   FT_LOCAL_DEF( FT_Error )
  44   af_loader_reset( AF_Loader  loader,
  45                    FT_Face    face )
  46   {
  47     FT_Error  error = AF_Err_Ok;
  48
  49
  50     loader->face    = face;
  51     loader->globals = (AF_FaceGlobals)face->autohint.data;
  52
  53     FT_GlyphLoader_Rewind( loader->gloader );
  54
  55     if ( loader->globals == NULL )
  56     {
  57       error = af_face_globals_new( face, &loader->globals );
  58       if ( !error )
  59       {
  60         face->autohint.data =
  61           (FT_Pointer)loader->globals;
  62         face->autohint.finalizer =
  63           (FT_Generic_Finalizer)af_face_globals_free;
  64       }
  65     }
  66
  67     return error;
  68   }
  69
  70
  71   /* Finalize glyph loader. */
  72
  73   FT_LOCAL_DEF( void )
  74   af_loader_done( AF_Loader  loader )
  75   {
  76     af_glyph_hints_done( &loader->hints );
  77
  78     loader->face    = NULL;
  79     loader->globals = NULL;
  80
  81 #ifdef FT_DEBUG_AUTOFIT
  82     _af_debug_hints = NULL;
  83 #endif
  84     FT_GlyphLoader_Done( loader->gloader );
  85     loader->gloader = NULL;
  86   }
  87
  88
  89   /* Load a single glyph component.  This routine calls itself */
  90   /* recursively, if necessary, and does the main work of      */
  91   /* `af_loader_load_glyph.'                                   */
  92
  93   static FT_Error
  94   af_loader_load_g( AF_Loader  loader,
  95                     AF_Scaler  scaler,
  96                     FT_UInt    glyph_index,
  97                     FT_Int32   load_flags,
  98                     FT_UInt    depth )
  99   {
 100     FT_Error          error;
 101     FT_Face           face     = loader->face;
 102     FT_GlyphLoader    gloader  = loader->gloader;
 103     AF_ScriptMetrics  metrics  = loader->metrics;
 104     AF_GlyphHints     hints    = &loader->hints;
 105     FT_GlyphSlot      slot     = face->glyph;
 106     FT_Slot_Internal  internal = slot->internal;
 107
 108
 109     error = FT_Load_Glyph( face, glyph_index, load_flags );
 110     if ( error )
 111       goto Exit;
 112
 113     loader->transformed = internal->glyph_transformed;
 114     if ( loader->transformed )
 115     {
 116       FT_Matrix  inverse;
 117
 118
 119       loader->trans_matrix = internal->glyph_matrix;
 120       loader->trans_delta  = internal->glyph_delta;
 121
 122       inverse = loader->trans_matrix;
 123       FT_Matrix_Invert( &inverse );
 124       FT_Vector_Transform( &loader->trans_delta, &inverse );
 125     }
 126
 127     /* set linear metrics */
 128     slot->linearHoriAdvance = slot->metrics.horiAdvance;
 129     slot->linearVertAdvance = slot->metrics.vertAdvance;
 130
 131     switch ( slot->format )
 132     {
 133     case FT_GLYPH_FORMAT_OUTLINE:
 134       /* translate the loaded glyph when an internal transform is needed */
 135       if ( loader->transformed )
 136         FT_Outline_Translate( &slot->outline,
 137                               loader->trans_delta.x,
 138                               loader->trans_delta.y );
 139
 140       /* copy the outline points in the loader's current               */
 141       /* extra points which is used to keep original glyph coordinates */
 142       error = FT_GLYPHLOADER_CHECK_POINTS( gloader,
 143                                            slot->outline.n_points + 4,
 144                                            slot->outline.n_contours );
 145       if ( error )
 146         goto Exit;
 147
 148       FT_ARRAY_COPY( gloader->current.outline.points,
 149                      slot->outline.points,
 150                      slot->outline.n_points );
 151
 152       FT_ARRAY_COPY( gloader->current.outline.contours,
 153                      slot->outline.contours,
 154                      slot->outline.n_contours );
 155
 156       FT_ARRAY_COPY( gloader->current.outline.tags,
 157                      slot->outline.tags,
 158                      slot->outline.n_points );
 159
 160       gloader->current.outline.n_points   = slot->outline.n_points;
 161       gloader->current.outline.n_contours = slot->outline.n_contours;
 162
 163       /* compute original horizontal phantom points (and ignore */
 164       /* vertical ones)                                         */
 165       loader->pp1.x = hints->x_delta;
 166       loader->pp1.y = hints->y_delta;
 167       loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
 168                                  hints->x_scale ) + hints->x_delta;
 169       loader->pp2.y = hints->y_delta;
 170
 171       /* be sure to check for spacing glyphs */
 172       if ( slot->outline.n_points == 0 )
 173         goto Hint_Metrics;
 174
 175       /* now load the slot image into the auto-outline and run the */
 176       /* automatic hinting process                                 */
 177       if ( metrics->clazz->script_hints_apply )
 178         metrics->clazz->script_hints_apply( hints,
 179                                             &gloader->current.outline,
 180                                             metrics );
 181
 182       /* we now need to adjust the metrics according to the change in */
 183       /* width/positioning that occurred during the hinting process   */
 184       if ( scaler->render_mode != FT_RENDER_MODE_LIGHT )
 185       {
 186         FT_Pos        old_rsb, old_lsb, new_lsb;
 187         FT_Pos        pp1x_uh, pp2x_uh;
 188         AF_AxisHints  axis  = &hints->axis[AF_DIMENSION_HORZ];
 189         AF_Edge       edge1 = axis->edges;         /* leftmost edge  */
 190         AF_Edge       edge2 = edge1 +
 191                               axis->num_edges - 1; /* rightmost edge */
 192
 193
 194         if ( axis->num_edges > 1 && AF_HINTS_DO_ADVANCE( hints ) )
 195         {
 196           old_rsb = loader->pp2.x - edge2->opos;
 197           old_lsb = edge1->opos;
 198           new_lsb = edge1->pos;
 199
 200           /* remember unhinted values to later account */
 201           /* for rounding errors                       */
 202
 203           pp1x_uh = new_lsb    - old_lsb;
 204           pp2x_uh = edge2->pos + old_rsb;
 205
 206           /* prefer too much space over too little space */
 207           /* for very small sizes                        */
 208
 209           if ( old_lsb < 24 )
 210             pp1x_uh -= 8;
 211
 212           if ( old_rsb < 24 )
 213             pp2x_uh += 8;
 214
 215           loader->pp1.x = FT_PIX_ROUND( pp1x_uh );
 216           loader->pp2.x = FT_PIX_ROUND( pp2x_uh );
 217
 218           if ( loader->pp1.x >= new_lsb && old_lsb > 0 )
 219             loader->pp1.x -= 64;
 220
 221           if ( loader->pp2.x <= edge2->pos && old_rsb > 0 )
 222             loader->pp2.x += 64;
 223
 224           slot->lsb_delta = loader->pp1.x - pp1x_uh;
 225           slot->rsb_delta = loader->pp2.x - pp2x_uh;
 226         }
 227         else
 228         {
 229           FT_Pos  pp1x = loader->pp1.x;
 230           FT_Pos  pp2x = loader->pp2.x;
 231
 232
 233           loader->pp1.x = FT_PIX_ROUND( pp1x );
 234           loader->pp2.x = FT_PIX_ROUND( pp2x );
 235
 236           slot->lsb_delta = loader->pp1.x - pp1x;
 237           slot->rsb_delta = loader->pp2.x - pp2x;
 238         }
 239       }
 240       else
 241       {
 242         FT_Pos  pp1x = loader->pp1.x;
 243         FT_Pos  pp2x = loader->pp2.x;
 244
 245
 246         loader->pp1.x = FT_PIX_ROUND( pp1x + hints->xmin_delta );
 247         loader->pp2.x = FT_PIX_ROUND( pp2x + hints->xmax_delta );
 248
 249         slot->lsb_delta = loader->pp1.x - pp1x;
 250         slot->rsb_delta = loader->pp2.x - pp2x;
 251       }
 252
 253       /* good, we simply add the glyph to our loader's base */
 254       FT_GlyphLoader_Add( gloader );
 255       break;
 256
 257     case FT_GLYPH_FORMAT_COMPOSITE:
 258       {
 259         FT_UInt      nn, num_subglyphs = slot->num_subglyphs;
 260         FT_UInt      num_base_subgs, start_point;
 261         FT_SubGlyph  subglyph;
 262
 263
 264         start_point = gloader->base.outline.n_points;
 265
 266         /* first of all, copy the subglyph descriptors in the glyph loader */
 267         error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs );
 268         if ( error )
 269           goto Exit;
 270
 271         FT_ARRAY_COPY( gloader->current.subglyphs,
 272                        slot->subglyphs,
 273                        num_subglyphs );
 274
 275         gloader->current.num_subglyphs = num_subglyphs;
 276         num_base_subgs                 = gloader->base.num_subglyphs;
 277
 278         /* now read each subglyph independently */
 279         for ( nn = 0; nn < num_subglyphs; nn++ )
 280         {
 281           FT_Vector  pp1, pp2;
 282           FT_Pos     x, y;
 283           FT_UInt    num_points, num_new_points, num_base_points;
 284
 285
 286           /* gloader.current.subglyphs can change during glyph loading due */
 287           /* to re-allocation -- we must recompute the current subglyph on */
 288           /* each iteration                                                */
 289           subglyph = gloader->base.subglyphs + num_base_subgs + nn;
 290
 291           pp1 = loader->pp1;
 292           pp2 = loader->pp2;
 293
 294           num_base_points = gloader->base.outline.n_points;
 295
 296           error = af_loader_load_g( loader, scaler, subglyph->index,
 297                                     load_flags, depth + 1 );
 298           if ( error )
 299             goto Exit;
 300
 301           /* recompute subglyph pointer */
 302           subglyph = gloader->base.subglyphs + num_base_subgs + nn;
 303
 304           if ( subglyph->flags & FT_SUBGLYPH_FLAG_USE_MY_METRICS )
 305           {
 306             pp1 = loader->pp1;
 307             pp2 = loader->pp2;
 308           }
 309           else
 310           {
 311             loader->pp1 = pp1;
 312             loader->pp2 = pp2;
 313           }
 314
 315           num_points     = gloader->base.outline.n_points;
 316           num_new_points = num_points - num_base_points;
 317
 318           /* now perform the transformation required for this subglyph */
 319
 320           if ( subglyph->flags & ( FT_SUBGLYPH_FLAG_SCALE    |
 321                                    FT_SUBGLYPH_FLAG_XY_SCALE |
 322                                    FT_SUBGLYPH_FLAG_2X2      ) )
 323           {
 324             FT_Vector*  cur   = gloader->base.outline.points +
 325                                 num_base_points;
 326             FT_Vector*  limit = cur + num_new_points;
 327
 328
 329             for ( ; cur < limit; cur++ )
 330               FT_Vector_Transform( cur, &subglyph->transform );
 331           }
 332
 333           /* apply offset */
 334
 335           if ( !( subglyph->flags & FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES ) )
 336           {
 337             FT_Int      k = subglyph->arg1;
 338             FT_UInt     l = subglyph->arg2;
 339             FT_Vector*  p1;
 340             FT_Vector*  p2;
 341
 342
 343             if ( start_point + k >= num_base_points         ||
 344                                l >= (FT_UInt)num_new_points )
 345             {
 346               error = AF_Err_Invalid_Composite;
 347               goto Exit;
 348             }
 349
 350             l += num_base_points;
 351
 352             /* for now, only use the current point coordinates;    */
 353             /* we may consider another approach in the near future */
 354             p1 = gloader->base.outline.points + start_point + k;
 355             p2 = gloader->base.outline.points + start_point + l;
 356
 357             x = p1->x - p2->x;
 358             y = p1->y - p2->y;
 359           }
 360           else
 361           {
 362             x = FT_MulFix( subglyph->arg1, hints->x_scale ) + hints->x_delta;
 363             y = FT_MulFix( subglyph->arg2, hints->y_scale ) + hints->y_delta;
 364
 365             x = FT_PIX_ROUND( x );
 366             y = FT_PIX_ROUND( y );
 367           }
 368
 369           {
 370             FT_Outline  dummy = gloader->base.outline;
 371
 372
 373             dummy.points  += num_base_points;
 374             dummy.n_points = (short)num_new_points;
 375
 376             FT_Outline_Translate( &dummy, x, y );
 377           }
 378         }
 379       }
 380       break;
 381
 382     default:
 383       /* we don't support other formats (yet?) */
 384       error = AF_Err_Unimplemented_Feature;
 385     }
 386
 387   Hint_Metrics:
 388     if ( depth == 0 )
 389     {
 390       FT_BBox    bbox;
 391       FT_Vector  vvector;
 392
 393
 394       vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
 395       vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
 396       vvector.x = FT_MulFix( vvector.x, metrics->scaler.x_scale );
 397       vvector.y = FT_MulFix( vvector.y, metrics->scaler.y_scale );
 398
 399       /* transform the hinted outline if needed */
 400       if ( loader->transformed )
 401       {
 402         FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
 403         FT_Vector_Transform( &vvector, &loader->trans_matrix );
 404       }
 405 #if 1
 406       /* we must translate our final outline by -pp1.x and compute */
 407       /* the new metrics                                           */
 408       if ( loader->pp1.x )
 409         FT_Outline_Translate( &gloader->base.outline, -loader->pp1.x, 0 );
 410 #endif
 411       FT_Outline_Get_CBox( &gloader->base.outline, &bbox );
 412
 413       bbox.xMin = FT_PIX_FLOOR( bbox.xMin );
 414       bbox.yMin = FT_PIX_FLOOR( bbox.yMin );
 415       bbox.xMax = FT_PIX_CEIL(  bbox.xMax );
 416       bbox.yMax = FT_PIX_CEIL(  bbox.yMax );
 417
 418       slot->metrics.width        = bbox.xMax - bbox.xMin;
 419       slot->metrics.height       = bbox.yMax - bbox.yMin;
 420       slot->metrics.horiBearingX = bbox.xMin;
 421       slot->metrics.horiBearingY = bbox.yMax;
 422
 423       slot->metrics.vertBearingX = FT_PIX_FLOOR( bbox.xMin + vvector.x );
 424       slot->metrics.vertBearingY = FT_PIX_FLOOR( bbox.yMax + vvector.y );
 425
 426       /* for mono-width fonts (like Andale, Courier, etc.) we need */
 427       /* to keep the original rounded advance width; ditto for     */
 428       /* digits if all have the same advance width                 */
 429 #if 0
 430       if ( !FT_IS_FIXED_WIDTH( slot->face ) )
 431         slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
 432       else
 433         slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
 434                                                x_scale );
 435 #else
 436       if ( scaler->render_mode != FT_RENDER_MODE_LIGHT                      &&
 437            ( FT_IS_FIXED_WIDTH( slot->face )                              ||
 438              ( af_face_globals_is_digit( loader->globals, glyph_index ) &&
 439                metrics->digits_have_same_width                          ) ) )
 440       {
 441         slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
 442                                                metrics->scaler.x_scale );
 443
 444         /* Set delta values to 0.  Otherwise code that uses them is */
 445         /* going to ruin the fixed advance width.                   */
 446         slot->lsb_delta = 0;
 447         slot->rsb_delta = 0;
 448       }
 449       else
 450       {
 451         /* non-spacing glyphs must stay as-is */
 452         if ( slot->metrics.horiAdvance )
 453           slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
 454       }
 455 #endif
 456
 457       slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
 458                                              metrics->scaler.y_scale );
 459
 460       slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );
 461       slot->metrics.vertAdvance = FT_PIX_ROUND( slot->metrics.vertAdvance );
 462
 463       /* now copy outline into glyph slot */
 464       FT_GlyphLoader_Rewind( internal->loader );
 465       error = FT_GlyphLoader_CopyPoints( internal->loader, gloader );
 466       if ( error )
 467         goto Exit;
 468
 469       /* reassign all outline fields except flags to protect them */
 470       slot->outline.n_contours = internal->loader->base.outline.n_contours;
 471       slot->outline.n_points   = internal->loader->base.outline.n_points;
 472       slot->outline.points     = internal->loader->base.outline.points;
 473       slot->outline.tags       = internal->loader->base.outline.tags;
 474       slot->outline.contours   = internal->loader->base.outline.contours;
 475
 476       slot->format  = FT_GLYPH_FORMAT_OUTLINE;
 477     }
 478
 479   Exit:
 480     return error;
 481   }
 482
 483
 484   /* Load a glyph. */
 485
 486   FT_LOCAL_DEF( FT_Error )
 487   af_loader_load_glyph( AF_Loader  loader,
 488                         FT_Face    face,
 489                         FT_UInt    gindex,
 490                         FT_Int32   load_flags )
 491   {
 492     FT_Error      error;
 493     FT_Size       size = face->size;
 494     AF_ScalerRec  scaler;
 495
 496
 497     if ( !size )
 498       return AF_Err_Invalid_Argument;
 499
 500     FT_ZERO( &scaler );
 501
 502     scaler.face    = face;
 503     scaler.x_scale = size->metrics.x_scale;
 504     scaler.x_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
 505     scaler.y_scale = size->metrics.y_scale;
 506     scaler.y_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
 507
 508     scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
 509     scaler.flags       = 0;  /* XXX: fix this */
 510
 511     error = af_loader_reset( loader, face );
 512     if ( !error )
 513     {
 514       AF_ScriptMetrics  metrics;
 515       FT_UInt           options = 0;
 516
 517
 518 #ifdef FT_OPTION_AUTOFIT2
 519       /* XXX: undocumented hook to activate the latin2 hinter */
 520       if ( load_flags & ( 1UL << 20 ) )
 521         options = 2;
 522 #endif
 523
 524       error = af_face_globals_get_metrics( loader->globals, gindex,
 525                                            options, &metrics );
 526       if ( !error )
 527       {
 528         loader->metrics = metrics;
 529
 530         if ( metrics->clazz->script_metrics_scale )
 531           metrics->clazz->script_metrics_scale( metrics, &scaler );
 532         else
 533           metrics->scaler = scaler;
 534
 535         load_flags |=  FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_TRANSFORM;
 536         load_flags &= ~FT_LOAD_RENDER;
 537
 538         if ( metrics->clazz->script_hints_init )
 539         {
 540           error = metrics->clazz->script_hints_init( &loader->hints,
 541                                                      metrics );
 542           if ( error )
 543             goto Exit;
 544         }
 545
 546         error = af_loader_load_g( loader, &scaler, gindex, load_flags, 0 );
 547       }
 548     }
 549   Exit:
 550     return error;
 551   }
 552
 553
 554 /* END */