ttcmap.c

下载来的一个看图软件的源代码

/***************************************************************************/
/*                                                                         */
/*  ttcmap.c                                                               */
/*                                                                         */
/*    TrueType character mapping table (cmap) support (body).              */
/*                                                                         */
/*  Copyright 1996-2001, 2002 by                                           */
/*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
/*                                                                         */
/*  This file is part of the FreeType project, and may only be used,       */
/*  modified, and distributed under the terms of the FreeType project      */
/*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
/*  this file you indicate that you have read the license and              */
/*  understand and accept it fully.                                        */
/*                                                                         */
/***************************************************************************/


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include "ttload.h"
#include "ttcmap.h"

#include "sferrors.h"


  /*************************************************************************/
  /*                                                                       */
  /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
  /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
  /* messages during execution.                                            */
  /*                                                                       */
#undef  FT_COMPONENT
#define FT_COMPONENT  trace_ttcmap


  FT_CALLBACK_DEF( FT_UInt )
  code_to_index0( TT_CMapTable  charmap,
                  FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_ULong )
  code_to_next0( TT_CMapTable  charmap,
                 FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_UInt )
  code_to_index2( TT_CMapTable  charmap,
                  FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_ULong )
  code_to_next2( TT_CMapTable  charmap,
                 FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_UInt )
  code_to_index4( TT_CMapTable  charmap,
                  FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_ULong )
  code_to_next4( TT_CMapTable  charmap,
                 FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_UInt )
  code_to_index6( TT_CMapTable  charmap,
                  FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_ULong )
  code_to_next6( TT_CMapTable  charmap,
                 FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_UInt )
  code_to_index8_12( TT_CMapTable  charmap,
                     FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_ULong )
  code_to_next8_12( TT_CMapTable  charmap,
                    FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_UInt )
  code_to_index10( TT_CMapTable  charmap,
                   FT_ULong      char_code );

  FT_CALLBACK_DEF( FT_ULong )
  code_to_next10( TT_CMapTable  charmap,
                  FT_ULong      char_code );


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_load_charmap                                               */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Loads a given TrueType character map into memory.                  */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face   :: A handle to the parent face object.                      */
  /*                                                                       */
  /*    stream :: A handle to the current stream object.                   */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    table  :: A pointer to a cmap object.                              */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  /* <Note>                                                                */
  /*    The function assumes that the stream is already in use (i.e.,      */
  /*    opened).  In case of error, all partially allocated tables are     */
  /*    released.                                                          */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_face_load_charmap( TT_Face       face,
                        TT_CMapTable  cmap,
                        FT_Stream     stream )
  {
    FT_Error     error;
    FT_Memory    memory;
    FT_UShort    num_SH, num_Seg, i;
    FT_ULong     j, n;

    FT_UShort    u, l;

    TT_CMap0     cmap0;
    TT_CMap2     cmap2;
    TT_CMap4     cmap4;
    TT_CMap6     cmap6;
    TT_CMap8_12  cmap8_12;
    TT_CMap10    cmap10;

    TT_CMap2SubHeader  cmap2sub;
    TT_CMap4Segment    segments;
    TT_CMapGroup       groups;


    if ( cmap->loaded )
      return SFNT_Err_Ok;

    memory = stream->memory;

    if ( FT_STREAM_SEEK( cmap->offset ) )
      return error;

    switch ( cmap->format )
    {
    case 0:
      cmap0 = &cmap->c.cmap0;

      if ( FT_READ_USHORT( cmap0->language )           ||
           FT_ALLOC( cmap0->glyphIdArray, 256L )       ||
           FT_STREAM_READ( cmap0->glyphIdArray, 256L ) )
        goto Fail;

      cmap->get_index     = code_to_index0;
      cmap->get_next_char = code_to_next0;
      break;

    case 2:
      num_SH = 0;
      cmap2  = &cmap->c.cmap2;

      /* allocate subheader keys */

      if ( FT_NEW_ARRAY( cmap2->subHeaderKeys, 256 ) ||
           FT_FRAME_ENTER( 2L + 512L )               )
        goto Fail;

      cmap2->language = FT_GET_USHORT();

      for ( i = 0; i < 256; i++ )
      {
        u = (FT_UShort)( FT_GET_USHORT() / 8 );
        cmap2->subHeaderKeys[i] = u;

        if ( num_SH < u )
          num_SH = u;
      }

      FT_FRAME_EXIT();

      /* load subheaders */

      cmap2->numGlyphId = l = (FT_UShort)(
        ( ( cmap->length - 2L * ( 256 + 3 ) - num_SH * 8L ) & 0xFFFFU ) / 2 );

      if ( FT_NEW_ARRAY( cmap2->subHeaders, num_SH + 1 ) ||
           FT_FRAME_ENTER( ( num_SH + 1 ) * 8L )         )
      {
        FT_FREE( cmap2->subHeaderKeys );
        goto Fail;
      }

      cmap2sub = cmap2->subHeaders;

      for ( i = 0; i <= num_SH; i++ )
      {
        cmap2sub->firstCode     = FT_GET_USHORT();
        cmap2sub->entryCount    = FT_GET_USHORT();
        cmap2sub->idDelta       = FT_GET_SHORT();
        /* we apply the location offset immediately */
        cmap2sub->idRangeOffset = (FT_UShort)(
          FT_GET_USHORT() - ( num_SH - i ) * 8 - 2 );

        cmap2sub++;
      }

      FT_FRAME_EXIT();

      /* load glyph IDs */

      if ( FT_NEW_ARRAY( cmap2->glyphIdArray, l ) ||
           FT_FRAME_ENTER( l * 2L )               )
      {
        FT_FREE( cmap2->subHeaders );
        FT_FREE( cmap2->subHeaderKeys );
        goto Fail;
      }

      for ( i = 0; i < l; i++ )
        cmap2->glyphIdArray[i] = FT_GET_USHORT();

      FT_FRAME_EXIT();

      cmap->get_index = code_to_index2;
      cmap->get_next_char = code_to_next2;
      break;

    case 4:
      cmap4 = &cmap->c.cmap4;

      /* load header */

      if ( FT_FRAME_ENTER( 10L ) )
        goto Fail;

      cmap4->language      = FT_GET_USHORT();
      cmap4->segCountX2    = FT_GET_USHORT();
      cmap4->searchRange   = FT_GET_USHORT();
      cmap4->entrySelector = FT_GET_USHORT();
      cmap4->rangeShift    = FT_GET_USHORT();

      num_Seg = (FT_UShort)( cmap4->segCountX2 / 2 );

      FT_FRAME_EXIT();

      /* load segments */

      if ( FT_NEW_ARRAY( cmap4->segments, num_Seg )   ||
           FT_FRAME_ENTER( ( num_Seg * 4 + 1 ) * 2L ) )
        goto Fail;

      segments = cmap4->segments;

      for ( i = 0; i < num_Seg; i++ )
        segments[i].endCount = FT_GET_USHORT();

      (void)FT_GET_USHORT();

      for ( i = 0; i < num_Seg; i++ )
        segments[i].startCount = FT_GET_USHORT();

      for ( i = 0; i < num_Seg; i++ )
        segments[i].idDelta = FT_GET_SHORT();

      for ( i = 0; i < num_Seg; i++ )
        segments[i].idRangeOffset = FT_GET_USHORT();

      FT_FRAME_EXIT();

      cmap4->numGlyphId = l = (FT_UShort)(
        ( ( cmap->length - ( 16L + 8L * num_Seg ) ) & 0xFFFFU ) / 2 );

      /* load IDs */

      if ( FT_NEW_ARRAY( cmap4->glyphIdArray, l ) ||
           FT_FRAME_ENTER( l * 2L )               )
      {
        FT_FREE( cmap4->segments );
        goto Fail;
      }

      for ( i = 0; i < l; i++ )
        cmap4->glyphIdArray[i] = FT_GET_USHORT();

      FT_FRAME_EXIT();

      cmap4->last_segment = cmap4->segments;

      cmap->get_index     = code_to_index4;
      cmap->get_next_char = code_to_next4;
      break;

    case 6:
      cmap6 = &cmap->c.cmap6;

      if ( FT_FRAME_ENTER( 6L ) )
        goto Fail;

      cmap6->language   = FT_GET_USHORT();
      cmap6->firstCode  = FT_GET_USHORT();
      cmap6->entryCount = FT_GET_USHORT();

      FT_FRAME_EXIT();

      l = cmap6->entryCount;

      if ( FT_NEW_ARRAY( cmap6->glyphIdArray, l ) ||
           FT_FRAME_ENTER( l * 2L )               )
        goto Fail;

      for ( i = 0; i < l; i++ )
        cmap6->glyphIdArray[i] = FT_GET_USHORT();

      FT_FRAME_EXIT();
      cmap->get_index     = code_to_index6;
      cmap->get_next_char = code_to_next6;
      break;

    case 8:
    case 12:
      cmap8_12 = &cmap->c.cmap8_12;

      if ( FT_FRAME_ENTER( 8L ) )
        goto Fail;

      cmap->length       = FT_GET_ULONG();
      cmap8_12->language = FT_GET_ULONG();

      FT_FRAME_EXIT();

      if ( cmap->format == 8 )
        if ( FT_STREAM_SKIP( 8192L ) )
          goto Fail;

      if ( FT_READ_ULONG( cmap8_12->nGroups ) )
        goto Fail;

      n = cmap8_12->nGroups;

      if ( FT_NEW_ARRAY( cmap8_12->groups, n ) ||
           FT_FRAME_ENTER( n * 3 * 4L )        )
        goto Fail;

      groups = cmap8_12->groups;

      for ( j = 0; j < n; j++ )
      {
        groups[j].startCharCode = FT_GET_ULONG();
        groups[j].endCharCode   = FT_GET_ULONG();
        groups[j].startGlyphID  = FT_GET_ULONG();
      }

      FT_FRAME_EXIT();

      cmap8_12->last_group = cmap8_12->groups;

      cmap->get_index     = code_to_index8_12;
      cmap->get_next_char = code_to_next8_12;
      break;

    case 10:
      cmap10 = &cmap->c.cmap10;

      if ( FT_FRAME_ENTER( 16L ) )
        goto Fail;

      cmap->length          = FT_GET_ULONG();
      cmap10->language      = FT_GET_ULONG();
      cmap10->startCharCode = FT_GET_ULONG();
      cmap10->numChars      = FT_GET_ULONG();

      FT_FRAME_EXIT();