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/src/freetype/src/sfnt/ttsbit.c

https://bitbucket.org/cabalistic/ogredeps/
C | 1508 lines | 860 code | 279 blank | 369 comment | 107 complexity | 28dfbc17a3f1a7f4908d7844f46b83c2 MD5 | raw file

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   1/***************************************************************************/
   2/*                                                                         */
   3/*  ttsbit.c                                                               */
   4/*                                                                         */
   5/*    TrueType and OpenType embedded bitmap support (body).                */
   6/*                                                                         */
   7/*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,   */
   8/*            2010 by                                                      */
   9/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
  10/*                                                                         */
  11/*  This file is part of the FreeType project, and may only be used,       */
  12/*  modified, and distributed under the terms of the FreeType project      */
  13/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  14/*  this file you indicate that you have read the license and              */
  15/*  understand and accept it fully.                                        */
  16/*                                                                         */
  17/***************************************************************************/
  18
  19#include <ft2build.h>
  20#include FT_INTERNAL_DEBUG_H
  21#include FT_INTERNAL_STREAM_H
  22#include FT_TRUETYPE_TAGS_H
  23
  24  /*
  25   *  Alas, the memory-optimized sbit loader can't be used when implementing
  26   *  the `old internals' hack
  27   */
  28#ifndef FT_CONFIG_OPTION_OLD_INTERNALS
  29
  30#include "ttsbit0.c"
  31
  32#else /* FT_CONFIG_OPTION_OLD_INTERNALS */
  33
  34#include <ft2build.h>
  35#include FT_INTERNAL_DEBUG_H
  36#include FT_INTERNAL_STREAM_H
  37#include FT_TRUETYPE_TAGS_H
  38#include "ttsbit.h"
  39
  40#include "sferrors.h"
  41
  42
  43  /*************************************************************************/
  44  /*                                                                       */
  45  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  46  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  47  /* messages during execution.                                            */
  48  /*                                                                       */
  49#undef  FT_COMPONENT
  50#define FT_COMPONENT  trace_ttsbit
  51
  52
  53  /*************************************************************************/
  54  /*                                                                       */
  55  /* <Function>                                                            */
  56  /*    blit_sbit                                                          */
  57  /*                                                                       */
  58  /* <Description>                                                         */
  59  /*    Blits a bitmap from an input stream into a given target.  Supports */
  60  /*    x and y offsets as well as byte padded lines.                      */
  61  /*                                                                       */
  62  /* <Input>                                                               */
  63  /*    target      :: The target bitmap/pixmap.                           */
  64  /*                                                                       */
  65  /*    source      :: The input packed bitmap data.                       */
  66  /*                                                                       */
  67  /*    line_bits   :: The number of bits per line.                        */
  68  /*                                                                       */
  69  /*    byte_padded :: A flag which is true if lines are byte-padded.      */
  70  /*                                                                       */
  71  /*    x_offset    :: The horizontal offset.                              */
  72  /*                                                                       */
  73  /*    y_offset    :: The vertical offset.                                */
  74  /*                                                                       */
  75  /* <Note>                                                                */
  76  /*    IMPORTANT: The x and y offsets are relative to the top corner of   */
  77  /*               the target bitmap (unlike the normal TrueType           */
  78  /*               convention).  A positive y offset indicates a downwards */
  79  /*               direction!                                              */
  80  /*                                                                       */
  81  static void
  82  blit_sbit( FT_Bitmap*  target,
  83             FT_Byte*    source,
  84             FT_Int      line_bits,
  85             FT_Bool     byte_padded,
  86             FT_Int      x_offset,
  87             FT_Int      y_offset,
  88             FT_Int      source_height )
  89  {
  90    FT_Byte*   line_buff;
  91    FT_Int     line_incr;
  92    FT_Int     height;
  93
  94    FT_UShort  acc;
  95    FT_UInt    loaded;
  96
  97
  98    /* first of all, compute starting write position */
  99    line_incr = target->pitch;
 100    line_buff = target->buffer;
 101
 102    if ( line_incr < 0 )
 103      line_buff -= line_incr * ( target->rows - 1 );
 104
 105    line_buff += ( x_offset >> 3 ) + y_offset * line_incr;
 106
 107    /***********************************************************************/
 108    /*                                                                     */
 109    /* We use the extra-classic `accumulator' trick to extract the bits    */
 110    /* from the source byte stream.                                        */
 111    /*                                                                     */
 112    /* Namely, the variable `acc' is a 16-bit accumulator containing the   */
 113    /* last `loaded' bits from the input stream.  The bits are shifted to  */
 114    /* the upmost position in `acc'.                                       */
 115    /*                                                                     */
 116    /***********************************************************************/
 117
 118    acc    = 0;  /* clear accumulator   */
 119    loaded = 0;  /* no bits were loaded */
 120
 121    for ( height = source_height; height > 0; height-- )
 122    {
 123      FT_Byte*  cur   = line_buff;        /* current write cursor          */
 124      FT_Int    count = line_bits;        /* # of bits to extract per line */
 125      FT_Byte   shift = (FT_Byte)( x_offset & 7 ); /* current write shift  */
 126      FT_Byte   space = (FT_Byte)( 8 - shift );
 127
 128
 129      /* first of all, read individual source bytes */
 130      if ( count >= 8 )
 131      {
 132        count -= 8;
 133        {
 134          do
 135          {
 136            FT_Byte  val;
 137
 138
 139            /* ensure that there are at least 8 bits in the accumulator */
 140            if ( loaded < 8 )
 141            {
 142              acc    |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded ));
 143              loaded += 8;
 144            }
 145
 146            /* now write one byte */
 147            val = (FT_Byte)( acc >> 8 );
 148            if ( shift )
 149            {
 150              cur[0] |= (FT_Byte)( val >> shift );
 151              cur[1] |= (FT_Byte)( val << space );
 152            }
 153            else
 154              cur[0] |= val;
 155
 156            cur++;
 157            acc   <<= 8;  /* remove bits from accumulator */
 158            loaded -= 8;
 159            count  -= 8;
 160
 161          } while ( count >= 0 );
 162        }
 163
 164        /* restore `count' to correct value */
 165        count += 8;
 166      }
 167
 168      /* now write remaining bits (count < 8) */
 169      if ( count > 0 )
 170      {
 171        FT_Byte  val;
 172
 173
 174        /* ensure that there are at least `count' bits in the accumulator */
 175        if ( (FT_Int)loaded < count )
 176        {
 177          acc    |= (FT_UShort)((FT_UShort)*source++ << ( 8 - loaded ));
 178          loaded += 8;
 179        }
 180
 181        /* now write remaining bits */
 182        val     = (FT_Byte)( ( (FT_Byte)( acc >> 8 ) ) & ~( 0xFF >> count ) );
 183        cur[0] |= (FT_Byte)( val >> shift );
 184
 185        if ( count > space )
 186          cur[1] |= (FT_Byte)( val << space );
 187
 188        acc   <<= count;
 189        loaded -= count;
 190      }
 191
 192      /* now, skip to next line */
 193      if ( byte_padded )
 194      {
 195        acc    = 0;
 196        loaded = 0;   /* clear accumulator on byte-padded lines */
 197      }
 198
 199      line_buff += line_incr;
 200    }
 201  }
 202
 203
 204  static const FT_Frame_Field  sbit_metrics_fields[] =
 205  {
 206#undef  FT_STRUCTURE
 207#define FT_STRUCTURE  TT_SBit_MetricsRec
 208
 209    FT_FRAME_START( 8 ),
 210      FT_FRAME_BYTE( height ),
 211      FT_FRAME_BYTE( width ),
 212
 213      FT_FRAME_CHAR( horiBearingX ),
 214      FT_FRAME_CHAR( horiBearingY ),
 215      FT_FRAME_BYTE( horiAdvance ),
 216
 217      FT_FRAME_CHAR( vertBearingX ),
 218      FT_FRAME_CHAR( vertBearingY ),
 219      FT_FRAME_BYTE( vertAdvance ),
 220    FT_FRAME_END
 221  };
 222
 223
 224  /*************************************************************************/
 225  /*                                                                       */
 226  /* <Function>                                                            */
 227  /*    Load_SBit_Const_Metrics                                            */
 228  /*                                                                       */
 229  /* <Description>                                                         */
 230  /*    Loads the metrics for `EBLC' index tables format 2 and 5.          */
 231  /*                                                                       */
 232  /* <Input>                                                               */
 233  /*    range  :: The target range.                                        */
 234  /*                                                                       */
 235  /*    stream :: The input stream.                                        */
 236  /*                                                                       */
 237  /* <Return>                                                              */
 238  /*    FreeType error code.  0 means success.                             */
 239  /*                                                                       */
 240  static FT_Error
 241  Load_SBit_Const_Metrics( TT_SBit_Range  range,
 242                           FT_Stream      stream )
 243  {
 244    FT_Error  error;
 245
 246
 247    if ( FT_READ_ULONG( range->image_size ) )
 248      return error;
 249
 250    return FT_STREAM_READ_FIELDS( sbit_metrics_fields, &range->metrics );
 251  }
 252
 253
 254  /*************************************************************************/
 255  /*                                                                       */
 256  /* <Function>                                                            */
 257  /*    Load_SBit_Range_Codes                                              */
 258  /*                                                                       */
 259  /* <Description>                                                         */
 260  /*    Loads the range codes for `EBLC' index tables format 4 and 5.      */
 261  /*                                                                       */
 262  /* <Input>                                                               */
 263  /*    range        :: The target range.                                  */
 264  /*                                                                       */
 265  /*    stream       :: The input stream.                                  */
 266  /*                                                                       */
 267  /*    load_offsets :: A flag whether to load the glyph offset table.     */
 268  /*                                                                       */
 269  /* <Return>                                                              */
 270  /*    FreeType error code.  0 means success.                             */
 271  /*                                                                       */
 272  static FT_Error
 273  Load_SBit_Range_Codes( TT_SBit_Range  range,
 274                         FT_Stream      stream,
 275                         FT_Bool        load_offsets )
 276  {
 277    FT_Error   error;
 278    FT_ULong   count, n, size;
 279    FT_Memory  memory = stream->memory;
 280
 281
 282    if ( FT_READ_ULONG( count ) )
 283      goto Exit;
 284
 285    range->num_glyphs = count;
 286
 287    /* Allocate glyph offsets table if needed */
 288    if ( load_offsets )
 289    {
 290      if ( FT_NEW_ARRAY( range->glyph_offsets, count ) )
 291        goto Exit;
 292
 293      size = count * 4L;
 294    }
 295    else
 296      size = count * 2L;
 297
 298    /* Allocate glyph codes table and access frame */
 299    if ( FT_NEW_ARRAY ( range->glyph_codes, count ) ||
 300         FT_FRAME_ENTER( size )                     )
 301      goto Exit;
 302
 303    for ( n = 0; n < count; n++ )
 304    {
 305      range->glyph_codes[n] = FT_GET_USHORT();
 306
 307      if ( load_offsets )
 308        range->glyph_offsets[n] = (FT_ULong)range->image_offset +
 309                                  FT_GET_USHORT();
 310    }
 311
 312    FT_FRAME_EXIT();
 313
 314  Exit:
 315    return error;
 316  }
 317
 318
 319  /*************************************************************************/
 320  /*                                                                       */
 321  /* <Function>                                                            */
 322  /*    Load_SBit_Range                                                    */
 323  /*                                                                       */
 324  /* <Description>                                                         */
 325  /*    Loads a given `EBLC' index/range table.                            */
 326  /*                                                                       */
 327  /* <Input>                                                               */
 328  /*    range  :: The target range.                                        */
 329  /*                                                                       */
 330  /*    stream :: The input stream.                                        */
 331  /*                                                                       */
 332  /* <Return>                                                              */
 333  /*    FreeType error code.  0 means success.                             */
 334  /*                                                                       */
 335  static FT_Error
 336  Load_SBit_Range( TT_SBit_Range  range,
 337                   FT_Stream      stream )
 338  {
 339    FT_Error   error;
 340    FT_Memory  memory = stream->memory;
 341
 342
 343    switch( range->index_format )
 344    {
 345    case 1:   /* variable metrics with 4-byte offsets */
 346    case 3:   /* variable metrics with 2-byte offsets */
 347      {
 348        FT_ULong  num_glyphs, n;
 349        FT_Int    size_elem;
 350        FT_Bool   large = FT_BOOL( range->index_format == 1 );
 351
 352
 353
 354        if ( range->last_glyph < range->first_glyph )
 355        {
 356          error = SFNT_Err_Invalid_File_Format;
 357          goto Exit;
 358        }
 359
 360        num_glyphs        = range->last_glyph - range->first_glyph + 1L;
 361        range->num_glyphs = num_glyphs;
 362        num_glyphs++;                       /* XXX: BEWARE - see spec */
 363
 364        size_elem = large ? 4 : 2;
 365
 366        if ( FT_NEW_ARRAY( range->glyph_offsets, num_glyphs ) ||
 367             FT_FRAME_ENTER( num_glyphs * size_elem )         )
 368          goto Exit;
 369
 370        for ( n = 0; n < num_glyphs; n++ )
 371          range->glyph_offsets[n] = (FT_ULong)( range->image_offset +
 372                                                ( large ? FT_GET_ULONG()
 373                                                        : FT_GET_USHORT() ) );
 374        FT_FRAME_EXIT();
 375      }
 376      break;
 377
 378    case 2:   /* all glyphs have identical metrics */
 379      error = Load_SBit_Const_Metrics( range, stream );
 380      break;
 381
 382    case 4:
 383      error = Load_SBit_Range_Codes( range, stream, 1 );
 384      break;
 385
 386    case 5:
 387      error = Load_SBit_Const_Metrics( range, stream );
 388      if ( !error )
 389        error = Load_SBit_Range_Codes( range, stream, 0 );
 390      break;
 391
 392    default:
 393      error = SFNT_Err_Invalid_File_Format;
 394    }
 395
 396  Exit:
 397    return error;
 398  }
 399
 400
 401  /*************************************************************************/
 402  /*                                                                       */
 403  /* <Function>                                                            */
 404  /*    tt_face_load_eblc                                                  */
 405  /*                                                                       */
 406  /* <Description>                                                         */
 407  /*    Loads the table of embedded bitmap sizes for this face.            */
 408  /*                                                                       */
 409  /* <Input>                                                               */
 410  /*    face   :: The target face object.                                  */
 411  /*                                                                       */
 412  /*    stream :: The input stream.                                        */
 413  /*                                                                       */
 414  /* <Return>                                                              */
 415  /*    FreeType error code.  0 means success.                             */
 416  /*                                                                       */
 417  FT_LOCAL_DEF( FT_Error )
 418  tt_face_load_eblc( TT_Face    face,
 419                     FT_Stream  stream )
 420  {
 421    FT_Error   error  = SFNT_Err_Ok;
 422    FT_Memory  memory = stream->memory;
 423    FT_Fixed   version;
 424    FT_ULong   num_strikes;
 425    FT_ULong   table_base;
 426
 427    static const FT_Frame_Field  sbit_line_metrics_fields[] =
 428    {
 429#undef  FT_STRUCTURE
 430#define FT_STRUCTURE  TT_SBit_LineMetricsRec
 431
 432      /* no FT_FRAME_START */
 433        FT_FRAME_CHAR( ascender ),
 434        FT_FRAME_CHAR( descender ),
 435        FT_FRAME_BYTE( max_width ),
 436
 437        FT_FRAME_CHAR( caret_slope_numerator ),
 438        FT_FRAME_CHAR( caret_slope_denominator ),
 439        FT_FRAME_CHAR( caret_offset ),
 440
 441        FT_FRAME_CHAR( min_origin_SB ),
 442        FT_FRAME_CHAR( min_advance_SB ),
 443        FT_FRAME_CHAR( max_before_BL ),
 444        FT_FRAME_CHAR( min_after_BL ),
 445        FT_FRAME_CHAR( pads[0] ),
 446        FT_FRAME_CHAR( pads[1] ),
 447      FT_FRAME_END
 448    };
 449
 450    static const FT_Frame_Field  strike_start_fields[] =
 451    {
 452#undef  FT_STRUCTURE
 453#define FT_STRUCTURE  TT_SBit_StrikeRec
 454
 455      /* no FT_FRAME_START */
 456        FT_FRAME_ULONG( ranges_offset ),
 457        FT_FRAME_SKIP_LONG,
 458        FT_FRAME_ULONG( num_ranges ),
 459        FT_FRAME_ULONG( color_ref ),
 460      FT_FRAME_END
 461    };
 462
 463    static const FT_Frame_Field  strike_end_fields[] =
 464    {
 465      /* no FT_FRAME_START */
 466        FT_FRAME_USHORT( start_glyph ),
 467        FT_FRAME_USHORT( end_glyph ),
 468        FT_FRAME_BYTE  ( x_ppem ),
 469        FT_FRAME_BYTE  ( y_ppem ),
 470        FT_FRAME_BYTE  ( bit_depth ),
 471        FT_FRAME_CHAR  ( flags ),
 472      FT_FRAME_END
 473    };
 474
 475
 476    face->num_sbit_strikes = 0;
 477
 478    /* this table is optional */
 479    error = face->goto_table( face, TTAG_EBLC, stream, 0 );
 480    if ( error )
 481      error = face->goto_table( face, TTAG_bloc, stream, 0 );
 482    if ( error )
 483      goto Exit;
 484
 485    table_base = FT_STREAM_POS();
 486    if ( FT_FRAME_ENTER( 8L ) )
 487      goto Exit;
 488
 489    version     = FT_GET_LONG();
 490    num_strikes = FT_GET_ULONG();
 491
 492    FT_FRAME_EXIT();
 493
 494    /* check version number and strike count */
 495    if ( version     != 0x00020000L ||
 496         num_strikes >= 0x10000L    )
 497    {
 498      FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version\n" ));
 499      error = SFNT_Err_Invalid_File_Format;
 500
 501      goto Exit;
 502    }
 503
 504    /* allocate the strikes table */
 505    if ( FT_NEW_ARRAY( face->sbit_strikes, num_strikes ) )
 506      goto Exit;
 507
 508    face->num_sbit_strikes = num_strikes;
 509
 510    /* now read each strike table separately */
 511    {
 512      TT_SBit_Strike  strike = face->sbit_strikes;
 513      FT_ULong        count  = num_strikes;
 514
 515
 516      if ( FT_FRAME_ENTER( 48L * num_strikes ) )
 517        goto Exit;
 518
 519      while ( count > 0 )
 520      {
 521        if ( FT_STREAM_READ_FIELDS( strike_start_fields, strike )             ||
 522             FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->hori ) ||
 523             FT_STREAM_READ_FIELDS( sbit_line_metrics_fields, &strike->vert ) ||
 524             FT_STREAM_READ_FIELDS( strike_end_fields, strike )               )
 525          break;
 526
 527        count--;
 528        strike++;
 529      }
 530
 531      FT_FRAME_EXIT();
 532    }
 533
 534    /* allocate the index ranges for each strike table */
 535    {
 536      TT_SBit_Strike  strike = face->sbit_strikes;
 537      FT_ULong        count  = num_strikes;
 538
 539
 540      while ( count > 0 )
 541      {
 542        TT_SBit_Range  range;
 543        FT_ULong       count2 = strike->num_ranges;
 544
 545
 546        /* read each range */
 547        if ( FT_STREAM_SEEK( table_base + strike->ranges_offset ) ||
 548             FT_FRAME_ENTER( strike->num_ranges * 8L )            )
 549          goto Exit;
 550
 551        if ( FT_NEW_ARRAY( strike->sbit_ranges, strike->num_ranges ) )
 552          goto Exit;
 553
 554        range = strike->sbit_ranges;
 555        while ( count2 > 0 )
 556        {
 557          range->first_glyph  = FT_GET_USHORT();
 558          range->last_glyph   = FT_GET_USHORT();
 559          range->table_offset = table_base + strike->ranges_offset +
 560                                  FT_GET_ULONG();
 561          count2--;
 562          range++;
 563        }
 564
 565        FT_FRAME_EXIT();
 566
 567        /* Now, read each index table */
 568        count2 = strike->num_ranges;
 569        range  = strike->sbit_ranges;
 570        while ( count2 > 0 )
 571        {
 572          /* Read the header */
 573          if ( FT_STREAM_SEEK( range->table_offset ) ||
 574               FT_FRAME_ENTER( 8L )                  )
 575            goto Exit;
 576
 577          range->index_format = FT_GET_USHORT();
 578          range->image_format = FT_GET_USHORT();
 579          range->image_offset = FT_GET_ULONG();
 580
 581          FT_FRAME_EXIT();
 582
 583          error = Load_SBit_Range( range, stream );
 584          if ( error )
 585            goto Exit;
 586
 587          count2--;
 588          range++;
 589        }
 590
 591        count--;
 592        strike++;
 593      }
 594    }
 595
 596  Exit:
 597    return error;
 598  }
 599
 600
 601  /*************************************************************************/
 602  /*                                                                       */
 603  /* <Function>                                                            */
 604  /*    tt_face_free_eblc                                                  */
 605  /*                                                                       */
 606  /* <Description>                                                         */
 607  /*    Releases the embedded bitmap tables.                               */
 608  /*                                                                       */
 609  /* <Input>                                                               */
 610  /*    face :: The target face object.                                    */
 611  /*                                                                       */
 612  FT_LOCAL_DEF( void )
 613  tt_face_free_eblc( TT_Face  face )
 614  {
 615    FT_Memory       memory       = face->root.memory;
 616    TT_SBit_Strike  strike       = face->sbit_strikes;
 617    TT_SBit_Strike  strike_limit = strike + face->num_sbit_strikes;
 618
 619
 620    if ( strike )
 621    {
 622      for ( ; strike < strike_limit; strike++ )
 623      {
 624        TT_SBit_Range  range       = strike->sbit_ranges;
 625        TT_SBit_Range  range_limit = range + strike->num_ranges;
 626
 627
 628        if ( range )
 629        {
 630          for ( ; range < range_limit; range++ )
 631          {
 632            /* release the glyph offsets and codes tables */
 633            /* where appropriate                          */
 634            FT_FREE( range->glyph_offsets );
 635            FT_FREE( range->glyph_codes );
 636          }
 637        }
 638        FT_FREE( strike->sbit_ranges );
 639        strike->num_ranges = 0;
 640      }
 641      FT_FREE( face->sbit_strikes );
 642    }
 643    face->num_sbit_strikes = 0;
 644  }
 645
 646
 647  FT_LOCAL_DEF( FT_Error )
 648  tt_face_set_sbit_strike( TT_Face          face,
 649                           FT_Size_Request  req,
 650                           FT_ULong*        astrike_index )
 651  {
 652    return FT_Match_Size( (FT_Face)face, req, 0, astrike_index );
 653  }
 654
 655
 656  FT_LOCAL_DEF( FT_Error )
 657  tt_face_load_strike_metrics( TT_Face           face,
 658                               FT_ULong          strike_index,
 659                               FT_Size_Metrics*  metrics )
 660  {
 661    TT_SBit_Strike  strike;
 662
 663
 664    if ( strike_index >= face->num_sbit_strikes )
 665      return SFNT_Err_Invalid_Argument;
 666
 667    strike = face->sbit_strikes + strike_index;
 668
 669    metrics->x_ppem = strike->x_ppem;
 670    metrics->y_ppem = strike->y_ppem;
 671
 672    metrics->ascender  = strike->hori.ascender << 6;
 673    metrics->descender = strike->hori.descender << 6;
 674
 675    /* XXX: Is this correct? */
 676    metrics->max_advance = ( strike->hori.min_origin_SB  +
 677                             strike->hori.max_width      +
 678                             strike->hori.min_advance_SB ) << 6;
 679
 680    metrics->height = metrics->ascender - metrics->descender;
 681
 682    return SFNT_Err_Ok;
 683  }
 684
 685
 686  /*************************************************************************/
 687  /*                                                                       */
 688  /* <Function>                                                            */
 689  /*    find_sbit_range                                                    */
 690  /*                                                                       */
 691  /* <Description>                                                         */
 692  /*    Scans a given strike's ranges and return, for a given glyph        */
 693  /*    index, the corresponding sbit range, and `EBDT' offset.            */
 694  /*                                                                       */
 695  /* <Input>                                                               */
 696  /*    glyph_index   :: The glyph index.                                  */
 697  /*                                                                       */
 698  /*    strike        :: The source/current sbit strike.                   */
 699  /*                                                                       */
 700  /* <Output>                                                              */
 701  /*    arange        :: The sbit range containing the glyph index.        */
 702  /*                                                                       */
 703  /*    aglyph_offset :: The offset of the glyph data in `EBDT' table.     */
 704  /*                                                                       */
 705  /* <Return>                                                              */
 706  /*    FreeType error code.  0 means the glyph index was found.           */
 707  /*                                                                       */
 708  static FT_Error
 709  find_sbit_range( FT_UInt          glyph_index,
 710                   TT_SBit_Strike   strike,
 711                   TT_SBit_Range   *arange,
 712                   FT_ULong        *aglyph_offset )
 713  {
 714    TT_SBit_RangeRec  *range, *range_limit;
 715
 716
 717    /* check whether the glyph index is within this strike's */
 718    /* glyph range                                           */
 719    if ( glyph_index < (FT_UInt)strike->start_glyph ||
 720         glyph_index > (FT_UInt)strike->end_glyph   )
 721      goto Fail;
 722
 723    /* scan all ranges in strike */
 724    range       = strike->sbit_ranges;
 725    range_limit = range + strike->num_ranges;
 726    if ( !range )
 727      goto Fail;
 728
 729    for ( ; range < range_limit; range++ )
 730    {
 731      if ( glyph_index >= (FT_UInt)range->first_glyph &&
 732           glyph_index <= (FT_UInt)range->last_glyph  )
 733      {
 734        FT_UShort  delta = (FT_UShort)( glyph_index - range->first_glyph );
 735
 736
 737        switch ( range->index_format )
 738        {
 739        case 1:
 740        case 3:
 741          *aglyph_offset = range->glyph_offsets[delta];
 742          break;
 743
 744        case 2:
 745          *aglyph_offset = range->image_offset +
 746                           range->image_size * delta;
 747          break;
 748
 749        case 4:
 750        case 5:
 751          {
 752            FT_ULong  n;
 753
 754
 755            for ( n = 0; n < range->num_glyphs; n++ )
 756            {
 757              if ( (FT_UInt)range->glyph_codes[n] == glyph_index )
 758              {
 759                if ( range->index_format == 4 )
 760                  *aglyph_offset = range->glyph_offsets[n];
 761                else
 762                  *aglyph_offset = range->image_offset +
 763                                   n * range->image_size;
 764                goto Found;
 765              }
 766            }
 767          }
 768
 769        /* fall-through */
 770        default:
 771          goto Fail;
 772        }
 773
 774      Found:
 775        /* return successfully! */
 776        *arange  = range;
 777        return SFNT_Err_Ok;
 778      }
 779    }
 780
 781  Fail:
 782    *arange        = 0;
 783    *aglyph_offset = 0;
 784
 785    return SFNT_Err_Invalid_Argument;
 786  }
 787
 788
 789  /*************************************************************************/
 790  /*                                                                       */
 791  /* <Function>                                                            */
 792  /*    tt_find_sbit_image                                                 */
 793  /*                                                                       */
 794  /* <Description>                                                         */
 795  /*    Checks whether an embedded bitmap (an `sbit') exists for a given   */
 796  /*    glyph, at a given strike.                                          */
 797  /*                                                                       */
 798  /* <Input>                                                               */
 799  /*    face          :: The target face object.                           */
 800  /*                                                                       */
 801  /*    glyph_index   :: The glyph index.                                  */
 802  /*                                                                       */
 803  /*    strike_index  :: The current strike index.                         */
 804  /*                                                                       */
 805  /* <Output>                                                              */
 806  /*    arange        :: The SBit range containing the glyph index.        */
 807  /*                                                                       */
 808  /*    astrike       :: The SBit strike containing the glyph index.       */
 809  /*                                                                       */
 810  /*    aglyph_offset :: The offset of the glyph data in `EBDT' table.     */
 811  /*                                                                       */
 812  /* <Return>                                                              */
 813  /*    FreeType error code.  0 means success.  Returns                    */
 814  /*    SFNT_Err_Invalid_Argument if no sbit exists for the requested      */
 815  /*    glyph.                                                             */
 816  /*                                                                       */
 817  FT_LOCAL( FT_Error )
 818  tt_find_sbit_image( TT_Face          face,
 819                      FT_UInt          glyph_index,
 820                      FT_ULong         strike_index,
 821                      TT_SBit_Range   *arange,
 822                      TT_SBit_Strike  *astrike,
 823                      FT_ULong        *aglyph_offset )
 824  {
 825    FT_Error        error;
 826    TT_SBit_Strike  strike;
 827
 828
 829    if ( !face->sbit_strikes                        ||
 830         ( face->num_sbit_strikes <= strike_index ) )
 831      goto Fail;
 832
 833    strike = &face->sbit_strikes[strike_index];
 834
 835    error = find_sbit_range( glyph_index, strike,
 836                             arange, aglyph_offset );
 837    if ( error )
 838      goto Fail;
 839
 840    *astrike = strike;
 841
 842    return SFNT_Err_Ok;
 843
 844  Fail:
 845    /* no embedded bitmap for this glyph in face */
 846    *arange        = 0;
 847    *astrike       = 0;
 848    *aglyph_offset = 0;
 849
 850    return SFNT_Err_Invalid_Argument;
 851  }
 852
 853
 854  /*************************************************************************/
 855  /*                                                                       */
 856  /* <Function>                                                            */
 857  /*    tt_load_sbit_metrics                                               */
 858  /*                                                                       */
 859  /* <Description>                                                         */
 860  /*    Gets the big metrics for a given SBit.                             */
 861  /*                                                                       */
 862  /* <Input>                                                               */
 863  /*    stream      :: The input stream.                                   */
 864  /*                                                                       */
 865  /*    range       :: The SBit range containing the glyph.                */
 866  /*                                                                       */
 867  /* <Output>                                                              */
 868  /*    big_metrics :: A big SBit metrics structure for the glyph.         */
 869  /*                                                                       */
 870  /* <Return>                                                              */
 871  /*    FreeType error code.  0 means success.                             */
 872  /*                                                                       */
 873  /* <Note>                                                                */
 874  /*    The stream cursor must be positioned at the glyph's offset within  */
 875  /*    the `EBDT' table before the call.                                  */
 876  /*                                                                       */
 877  /*    If the image format uses variable metrics, the stream cursor is    */
 878  /*    positioned just after the metrics header in the `EBDT' table on    */
 879  /*    function exit.                                                     */
 880  /*                                                                       */
 881  FT_LOCAL( FT_Error )
 882  tt_load_sbit_metrics( FT_Stream        stream,
 883                        TT_SBit_Range    range,
 884                        TT_SBit_Metrics  metrics )
 885  {
 886    FT_Error  error = SFNT_Err_Ok;
 887
 888
 889    switch ( range->image_format )
 890    {
 891    case 1:
 892    case 2:
 893    case 8:
 894      /* variable small metrics */
 895      {
 896        TT_SBit_SmallMetricsRec  smetrics;
 897
 898        static const FT_Frame_Field  sbit_small_metrics_fields[] =
 899        {
 900#undef  FT_STRUCTURE
 901#define FT_STRUCTURE  TT_SBit_SmallMetricsRec
 902
 903          FT_FRAME_START( 5 ),
 904            FT_FRAME_BYTE( height ),
 905            FT_FRAME_BYTE( width ),
 906            FT_FRAME_CHAR( bearingX ),
 907            FT_FRAME_CHAR( bearingY ),
 908            FT_FRAME_BYTE( advance ),
 909          FT_FRAME_END
 910        };
 911
 912
 913        /* read small metrics */
 914        if ( FT_STREAM_READ_FIELDS( sbit_small_metrics_fields, &smetrics ) )
 915          goto Exit;
 916
 917        /* convert it to a big metrics */
 918        metrics->height       = smetrics.height;
 919        metrics->width        = smetrics.width;
 920        metrics->horiBearingX = smetrics.bearingX;
 921        metrics->horiBearingY = smetrics.bearingY;
 922        metrics->horiAdvance  = smetrics.advance;
 923
 924        /* these metrics are made up at a higher level when */
 925        /* needed.                                          */
 926        metrics->vertBearingX = 0;
 927        metrics->vertBearingY = 0;
 928        metrics->vertAdvance  = 0;
 929      }
 930      break;
 931
 932    case 6:
 933    case 7:
 934    case 9:
 935      /* variable big metrics */
 936      if ( FT_STREAM_READ_FIELDS( sbit_metrics_fields, metrics ) )
 937        goto Exit;
 938      break;
 939
 940    case 5:
 941    default:  /* constant metrics */
 942      if ( range->index_format == 2 || range->index_format == 5 )
 943        *metrics = range->metrics;
 944      else
 945        return SFNT_Err_Invalid_File_Format;
 946   }
 947
 948  Exit:
 949    return error;
 950  }
 951
 952
 953  /*************************************************************************/
 954  /*                                                                       */
 955  /* <Function>                                                            */
 956  /*    crop_bitmap                                                        */
 957  /*                                                                       */
 958  /* <Description>                                                         */
 959  /*    Crops a bitmap to its tightest bounding box, and adjusts its       */
 960  /*    metrics.                                                           */
 961  /*                                                                       */
 962  /* <InOut>                                                               */
 963  /*    map     :: The bitmap.                                             */
 964  /*                                                                       */
 965  /*    metrics :: The corresponding metrics structure.                    */
 966  /*                                                                       */
 967  static void
 968  crop_bitmap( FT_Bitmap*       map,
 969               TT_SBit_Metrics  metrics )
 970  {
 971    /***********************************************************************/
 972    /*                                                                     */
 973    /* In this situation, some bounding boxes of embedded bitmaps are too  */
 974    /* large.  We need to crop it to a reasonable size.                    */
 975    /*                                                                     */
 976    /*      ---------                                                      */
 977    /*      |       |                -----                                 */
 978    /*      |  ***  |                |***|                                 */
 979    /*      |   *   |                | * |                                 */
 980    /*      |   *   |    ------>     | * |                                 */
 981    /*      |   *   |                | * |                                 */
 982    /*      |   *   |                | * |                                 */
 983    /*      |  ***  |                |***|                                 */
 984    /*      ---------                -----                                 */
 985    /*                                                                     */
 986    /***********************************************************************/
 987
 988    FT_Int    rows, count;
 989    FT_Long   line_len;
 990    FT_Byte*  line;
 991
 992
 993    /***********************************************************************/
 994    /*                                                                     */
 995    /* first of all, check the top-most lines of the bitmap, and remove    */
 996    /* them if they're empty.                                              */
 997    /*                                                                     */
 998    {
 999      line     = (FT_Byte*)map->buffer;
1000      rows     = map->rows;
1001      line_len = map->pitch;
1002
1003
1004      for ( count = 0; count < rows; count++ )
1005      {
1006        FT_Byte*  cur   = line;
1007        FT_Byte*  limit = line + line_len;
1008
1009
1010        for ( ; cur < limit; cur++ )
1011          if ( cur[0] )
1012            goto Found_Top;
1013
1014        /* the current line was empty - skip to next one */
1015        line  = limit;
1016      }
1017
1018    Found_Top:
1019      /* check that we have at least one filled line */
1020      if ( count >= rows )
1021        goto Empty_Bitmap;
1022
1023      /* now, crop the empty upper lines */
1024      if ( count > 0 )
1025      {
1026        line = (FT_Byte*)map->buffer;
1027
1028        FT_MEM_MOVE( line, line + count * line_len,
1029                     ( rows - count ) * line_len );
1030
1031        metrics->height       = (FT_Byte)( metrics->height - count );
1032        metrics->horiBearingY = (FT_Char)( metrics->horiBearingY - count );
1033        metrics->vertBearingY = (FT_Char)( metrics->vertBearingY - count );
1034
1035        map->rows -= count;
1036        rows      -= count;
1037      }
1038    }
1039
1040    /***********************************************************************/
1041    /*                                                                     */
1042    /* second, crop the lower lines                                        */
1043    /*                                                                     */
1044    {
1045      line = (FT_Byte*)map->buffer + ( rows - 1 ) * line_len;
1046
1047      for ( count = 0; count < rows; count++ )
1048      {
1049        FT_Byte*  cur   = line;
1050        FT_Byte*  limit = line + line_len;
1051
1052
1053        for ( ; cur < limit; cur++ )
1054          if ( cur[0] )
1055            goto Found_Bottom;
1056
1057        /* the current line was empty - skip to previous one */
1058        line -= line_len;
1059      }
1060
1061    Found_Bottom:
1062      if ( count > 0 )
1063      {
1064        metrics->height  = (FT_Byte)( metrics->height - count );
1065        rows            -= count;
1066        map->rows       -= count;
1067      }
1068    }
1069
1070    /***********************************************************************/
1071    /*                                                                     */
1072    /* third, get rid of the space on the left side of the glyph           */
1073    /*                                                                     */
1074    do
1075    {
1076      FT_Byte*  limit;
1077
1078
1079      line  = (FT_Byte*)map->buffer;
1080      limit = line + rows * line_len;
1081
1082      for ( ; line < limit; line += line_len )
1083        if ( line[0] & 0x80 )
1084          goto Found_Left;
1085
1086      /* shift the whole glyph one pixel to the left */
1087      line  = (FT_Byte*)map->buffer;
1088      limit = line + rows * line_len;
1089
1090      for ( ; line < limit; line += line_len )
1091      {
1092        FT_Int    n, width = map->width;
1093        FT_Byte   old;
1094        FT_Byte*  cur = line;
1095
1096
1097        old = (FT_Byte)(cur[0] << 1);
1098        for ( n = 8; n < width; n += 8 )
1099        {
1100          FT_Byte  val;
1101
1102
1103          val    = cur[1];
1104          cur[0] = (FT_Byte)( old | ( val >> 7 ) );
1105          old    = (FT_Byte)( val << 1 );
1106          cur++;
1107        }
1108        cur[0] = old;
1109      }
1110
1111      map->width--;
1112      metrics->horiBearingX++;
1113      metrics->vertBearingX++;
1114      metrics->width--;
1115
1116    } while ( map->width > 0 );
1117
1118  Found_Left:
1119
1120    /***********************************************************************/
1121    /*                                                                     */
1122    /* finally, crop the bitmap width to get rid of the space on the right */
1123    /* side of the glyph.                                                  */
1124    /*                                                                     */
1125    do
1126    {
1127      FT_Int    right = map->width - 1;
1128      FT_Byte*  limit;
1129      FT_Byte   mask;
1130
1131
1132      line  = (FT_Byte*)map->buffer + ( right >> 3 );
1133      limit = line + rows * line_len;
1134      mask  = (FT_Byte)( 0x80 >> ( right & 7 ) );
1135
1136      for ( ; line < limit; line += line_len )
1137        if ( line[0] & mask )
1138          goto Found_Right;
1139
1140      /* crop the whole glyph to the right */
1141      map->width--;
1142      metrics->width--;
1143
1144    } while ( map->width > 0 );
1145
1146  Found_Right:
1147    /* all right, the bitmap was cropped */
1148    return;
1149
1150  Empty_Bitmap:
1151    map->width      = 0;
1152    map->rows       = 0;
1153    map->pitch      = 0;
1154    map->pixel_mode = FT_PIXEL_MODE_MONO;
1155  }
1156
1157
1158  static FT_Error
1159  Load_SBit_Single( FT_Bitmap*       map,
1160                    FT_Int           x_offset,
1161                    FT_Int           y_offset,
1162                    FT_Int           pix_bits,
1163                    FT_UShort        image_format,
1164                    TT_SBit_Metrics  metrics,
1165                    FT_Stream        stream )
1166  {
1167    FT_Error  error;
1168
1169
1170    /* check that the source bitmap fits into the target pixmap */
1171    if ( x_offset < 0 || x_offset + metrics->width  > map->width ||
1172         y_offset < 0 || y_offset + metrics->height > map->rows  )
1173    {
1174      error = SFNT_Err_Invalid_Argument;
1175
1176      goto Exit;
1177    }
1178
1179    {
1180      FT_Int   glyph_width  = metrics->width;
1181      FT_Int   glyph_height = metrics->height;
1182      FT_Int   glyph_size;
1183      FT_Int   line_bits    = pix_bits * glyph_width;
1184      FT_Bool  pad_bytes    = 0;
1185
1186
1187      /* compute size of glyph image */
1188      switch ( image_format )
1189      {
1190      case 1:  /* byte-padded formats */
1191      case 6:
1192        {
1193          FT_Int  line_length;
1194
1195
1196          switch ( pix_bits )
1197          {
1198          case 1:
1199            line_length = ( glyph_width + 7 ) >> 3;
1200            break;
1201          case 2:
1202            line_length = ( glyph_width + 3 ) >> 2;
1203            break;
1204          case 4:
1205            line_length = ( glyph_width + 1 ) >> 1;
1206            break;
1207          default:
1208            line_length =   glyph_width;
1209          }
1210
1211          glyph_size = glyph_height * line_length;
1212          pad_bytes  = 1;
1213        }
1214        break;
1215
1216      case 2:
1217      case 5:
1218      case 7:
1219        line_bits  =   glyph_width  * pix_bits;
1220        glyph_size = ( glyph_height * line_bits + 7 ) >> 3;
1221        break;
1222
1223      default:  /* invalid format */
1224        return SFNT_Err_Invalid_File_Format;
1225      }
1226
1227      /* Now read data and draw glyph into target pixmap       */
1228      if ( FT_FRAME_ENTER( glyph_size ) )
1229        goto Exit;
1230
1231      /* don't forget to multiply `x_offset' by `map->pix_bits' as */
1232      /* the sbit blitter doesn't make a difference between pixmap */
1233      /* depths.                                                   */
1234      blit_sbit( map, (FT_Byte*)stream->cursor, line_bits, pad_bytes,
1235                 x_offset * pix_bits, y_offset, metrics->height );
1236
1237      FT_FRAME_EXIT();
1238    }
1239
1240  Exit:
1241    return error;
1242  }
1243
1244
1245  static FT_Error
1246  Load_SBit_Image( TT_SBit_Strike   strike,
1247                   TT_SBit_Range    range,
1248                   FT_ULong         ebdt_pos,
1249                   FT_ULong         glyph_offset,
1250                   FT_GlyphSlot     slot,
1251                   FT_Int           x_offset,
1252                   FT_Int           y_offset,
1253                   FT_Stream        stream,
1254                   TT_SBit_Metrics  metrics,
1255                   FT_Int           depth )
1256  {
1257    FT_Memory   memory = stream->memory;
1258    FT_Bitmap*  map    = &slot->bitmap;
1259    FT_Error    error;
1260
1261
1262    /* place stream at beginning of glyph data and read metrics */
1263    if ( FT_STREAM_SEEK( ebdt_pos + glyph_offset ) )
1264      goto Exit;
1265
1266    error = tt_load_sbit_metrics( stream, range, metrics );
1267    if ( error )
1268      goto Exit;
1269
1270    /* This function is recursive.  At the top-level call, we  */
1271    /* compute the dimensions of the higher-level glyph to     */
1272    /* allocate the final pixmap buffer.                       */
1273    if ( depth == 0 )
1274    {
1275      FT_Long  size;
1276
1277
1278      map->width = metrics->width;
1279      map->rows  = metrics->height;
1280
1281      switch ( strike->bit_depth )
1282      {
1283      case 1:
1284        map->pixel_mode = FT_PIXEL_MODE_MONO;
1285        map->pitch      = ( map->width + 7 ) >> 3;
1286        break;
1287
1288      case 2:
1289        map->pixel_mode = FT_PIXEL_MODE_GRAY2;
1290        map->pitch      = ( map->width + 3 ) >> 2;
1291        break;
1292
1293      case 4:
1294        map->pixel_mode = FT_PIXEL_MODE_GRAY4;
1295        map->pitch      = ( map->width + 1 ) >> 1;
1296        break;
1297
1298      case 8:
1299        map->pixel_mode = FT_PIXEL_MODE_GRAY;
1300        map->pitch      = map->width;
1301        break;
1302
1303      default:
1304        return SFNT_Err_Invalid_File_Format;
1305      }
1306
1307      size = map->rows * map->pitch;
1308
1309      /* check that there is no empty image */
1310      if ( size == 0 )
1311        goto Exit;     /* exit successfully! */
1312
1313      error = ft_glyphslot_alloc_bitmap( slot, size );
1314      if (error)
1315        goto Exit;
1316    }
1317
1318    switch ( range->image_format )
1319    {
1320    case 1:  /* single sbit image - load it */
1321    case 2:
1322    case 5:
1323    case 6:
1324    case 7:
1325      return Load_SBit_Single( map, x_offset, y_offset, strike->bit_depth,
1326                               range->image_format, metrics, stream );
1327
1328    case 8:  /* compound format */
1329      if ( FT_STREAM_SKIP( 1L ) )
1330      {
1331        error = SFNT_Err_Invalid_Stream_Skip;
1332        goto Exit;
1333      }
1334      /* fallthrough */
1335
1336    case 9:
1337      break;
1338
1339    default: /* invalid image format */
1340      return SFNT_Err_Invalid_File_Format;
1341    }
1342
1343    /* All right, we have a compound format.  First of all, read */
1344    /* the array of elements.                                    */
1345    {
1346      TT_SBit_Component  components = NULL;
1347      TT_SBit_Component  comp;
1348      FT_UShort          num_components, count;
1349
1350
1351      if ( FT_READ_USHORT( num_components )           ||
1352           FT_NEW_ARRAY( components, num_components ) )
1353        goto Exit;
1354
1355      count = num_components;
1356
1357      if ( FT_FRAME_ENTER( 4L * num_components ) )
1358        goto Fail_Memory;
1359
1360      for ( comp = components; count > 0; count--, comp++ )
1361      {
1362        comp->glyph_code = FT_GET_USHORT();
1363        comp->x_offset   = FT_GET_CHAR();
1364        comp->y_offset   = FT_GET_CHAR();
1365      }
1366
1367      FT_FRAME_EXIT();
1368
1369      /* Now recursively load each element glyph */
1370      count = num_components;
1371      comp  = components;
1372      for ( ; count > 0; count--, comp++ )
1373      {
1374        TT_SBit_Range       elem_range;
1375        TT_SBit_MetricsRec  elem_metrics;
1376        FT_ULong            elem_offset;
1377
1378
1379        /* find the range for this element */
1380        error = find_sbit_range( comp->glyph_code,
1381                                 strike,
1382                                 &elem_range,
1383                                 &elem_offset );
1384        if ( error )
1385          goto Fail_Memory;
1386
1387        /* now load the element, recursively */
1388        error = Load_SBit_Image( strike,
1389                                 elem_range,
1390                                 ebdt_pos,
1391                                 elem_offset,
1392                                 slot,
1393                                 x_offset + comp->x_offset,
1394                                 y_offset + comp->y_offset,
1395                                 stream,
1396                                 &elem_metrics,
1397                                 depth + 1 );
1398        if ( error )
1399          goto Fail_Memory;
1400      }
1401
1402    Fail_Memory:
1403      FT_FREE( components );
1404    }
1405
1406  Exit:
1407    return error;
1408  }
1409
1410
1411  /*************************************************************************/
1412  /*                                                                       */
1413  /* <Function>                                                            */
1414  /*    tt_face_load_sbit_image                                            */
1415  /*                                                                       */
1416  /* <Description>                                                         */
1417  /*    Loads a given glyph sbit image from the font resource.  This also  */
1418  /*  …

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