kc3-lang/freetype/src/sfnt/ttcmap.c

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• Hash : a90663f5
  Author :
  Date : 2000-07-08T00:41:13
  

  vast clean-up of the sources in order to allow flat directory compilation (by defining the FT_FLAT_COMPILE macro at compile time..) moved "freetype2/BUILD" to "freetype2/docs/BUILD"

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• src/sfnt/ttcmap.c

• /***************************************************************************/
  /*                                                                         */
  /*  ttcmap.c                                                               */
  /*                                                                         */
  /*    TrueType character mapping table (cmap) support (body).              */
  /*                                                                         */
  /*  Copyright 1996-2000 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 <freetype/internal/ftdebug.h>
  #include <freetype/internal/tterrors.h>
  
  #ifdef FT_FLAT_COMPILE
  #include "ttload.h"
  #include "ttcmap.h"
  #else
  #include <sfnt/ttload.h>
  #include <sfnt/ttcmap.h>
  #endif
  
  
  
  
    /*************************************************************************/
    /*                                                                       */
    /* 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
  
  
    static FT_UInt  code_to_index0( TT_CMapTable*  charmap,
                                    FT_ULong       char_code );
    static FT_UInt  code_to_index2( TT_CMapTable*  charmap,
                                    FT_ULong       char_code );
    static FT_UInt  code_to_index4( TT_CMapTable*  charmap,
                                    FT_ULong       char_code );
    static FT_UInt  code_to_index6( TT_CMapTable*  charmap,
                                    FT_ULong       char_code );
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    TT_CharMap_Load                                                    */
    /*                                                                       */
    /* <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.                                                          */
    /*                                                                       */
    LOCAL_FUNC
    FT_Error  TT_CharMap_Load( TT_Face        face,
                               TT_CMapTable*  cmap,
                               FT_Stream      stream )
    {
      FT_Error   error;
      FT_Memory  memory;
      FT_UShort  num_SH, num_Seg, i;
  
      FT_UShort  u, l;
  
      TT_CMap0*  cmap0;
      TT_CMap2*  cmap2;
      TT_CMap4*  cmap4;
      TT_CMap6*  cmap6;
  
      TT_CMap2SubHeader*  cmap2sub;
      TT_CMap4Segment*    segments;
  
  
      if ( cmap->loaded )
        return TT_Err_Ok;
  
      memory = stream->memory;
  
      if ( FILE_Seek( cmap->offset ) )
        return error;
  
      switch ( cmap->format )
      {
      case 0:
        cmap0 = &cmap->c.cmap0;
  
        if ( ALLOC( cmap0->glyphIdArray, 256L )            ||
             FILE_Read( cmap0->glyphIdArray, 256L ) )
           goto Fail;
  
        cmap->get_index = code_to_index0;
        break;
  
      case 2:
        num_SH = 0;
        cmap2  = &cmap->c.cmap2;
  
        /* allocate subheader keys */
  
        if ( ALLOC_ARRAY( cmap2->subHeaderKeys, 256, FT_UShort ) ||
             ACCESS_Frame( 512L )                                )
          goto Fail;
  
        for ( i = 0; i < 256; i++ )
        {
          u = GET_UShort() / 8;
          cmap2->subHeaderKeys[i] = u;
  
          if ( num_SH < u )
            num_SH = u;
        }
  
        FORGET_Frame();
  
        /* load subheaders */
  
        cmap2->numGlyphId = l =
          ( ( cmap->length - 2L * ( 256 + 3 ) - num_SH * 8L ) & 0xFFFF ) / 2;
  
        if ( ALLOC_ARRAY( cmap2->subHeaders,
                          num_SH + 1,
                          TT_CMap2SubHeader )    ||
             ACCESS_Frame( ( num_SH + 1 ) * 8L ) )
          goto Fail;
  
        cmap2sub = cmap2->subHeaders;
  
        for ( i = 0; i <= num_SH; i++ )
        {
          cmap2sub->firstCode     = GET_UShort();
          cmap2sub->entryCount    = GET_UShort();
          cmap2sub->idDelta       = GET_Short();
          /* we apply the location offset immediately */
          cmap2sub->idRangeOffset = GET_UShort() - ( num_SH - i ) * 8 - 2;
  
          cmap2sub++;
        }
  
        FORGET_Frame();
  
        /* load glyph IDs */
  
        if ( ALLOC_ARRAY( cmap2->glyphIdArray, l, FT_UShort ) ||
             ACCESS_Frame( l * 2L )                           )
          goto Fail;
  
        for ( i = 0; i < l; i++ )
          cmap2->glyphIdArray[i] = GET_UShort();
  
        FORGET_Frame();
  
        cmap->get_index = code_to_index2;
        break;
  
      case 4:
        cmap4 = &cmap->c.cmap4;
  
        /* load header */
  
        if ( ACCESS_Frame( 8L ) )
          goto Fail;
  
        cmap4->segCountX2    = GET_UShort();
        cmap4->searchRange   = GET_UShort();
        cmap4->entrySelector = GET_UShort();
        cmap4->rangeShift    = GET_UShort();
  
        num_Seg = cmap4->segCountX2 / 2;
  
        FORGET_Frame();
  
        /* load segments */
  
        if ( ALLOC_ARRAY( cmap4->segments,
                          num_Seg,
                          TT_CMap4Segment )           ||
             ACCESS_Frame( ( num_Seg * 4 + 1 ) * 2L ) )
          goto Fail;
  
        segments = cmap4->segments;
  
        for ( i = 0; i < num_Seg; i++ )
          segments[i].endCount      = GET_UShort();
  
        (void)GET_UShort();
  
        for ( i = 0; i < num_Seg; i++ )
          segments[i].startCount    = GET_UShort();
  
        for ( i = 0; i < num_Seg; i++ )
          segments[i].idDelta       = GET_Short();
  
        for ( i = 0; i < num_Seg; i++ )
          segments[i].idRangeOffset = GET_UShort();
  
        FORGET_Frame();
  
        cmap4->numGlyphId = l =
          ( ( cmap->length - ( 16L + 8L * num_Seg ) ) & 0xFFFF ) / 2;
  
        /* load IDs */
  
        if ( ALLOC_ARRAY( cmap4->glyphIdArray, l, FT_UShort ) ||
             ACCESS_Frame( l * 2L )                           )
          goto Fail;
  
        for ( i = 0; i < l; i++ )
          cmap4->glyphIdArray[i] = GET_UShort();
  
        FORGET_Frame();
  
        cmap->get_index = code_to_index4;
  
        cmap4->last_segment = cmap4->segments;
        break;
  
      case 6:
        cmap6 = &cmap->c.cmap6;
  
        if ( ACCESS_Frame( 4L ) )
          goto Fail;
  
        cmap6->firstCode  = GET_UShort();
        cmap6->entryCount = GET_UShort();
  
        FORGET_Frame();
  
        l = cmap6->entryCount;
  
        if ( ALLOC_ARRAY( cmap6->glyphIdArray,
                          cmap6->entryCount,
                          FT_Short )           ||
             ACCESS_Frame( l * 2L )            )
          goto Fail;
  
        for ( i = 0; i < l; i++ )
          cmap6->glyphIdArray[i] = GET_UShort();
  
        FORGET_Frame();
        cmap->get_index = code_to_index6;
        break;
  
      default:   /* corrupt character mapping table */
        return TT_Err_Invalid_CharMap_Format;
  
      }
  
      return TT_Err_Ok;
  
    Fail:
      TT_CharMap_Free( face, cmap );
      return error;
    }
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    TT_CharMap_Free                                                    */
    /*                                                                       */
    /* <Description>                                                         */
    /*    Destroys a character mapping table.                                */
    /*                                                                       */
    /* <Input>                                                               */
    /*    face :: A handle to the parent face object.                        */
    /*    cmap :: A handle to a cmap object.                                 */
    /*                                                                       */
    /* <Return>                                                              */
    /*    FreeType error code.  0 means success.                             */
    /*                                                                       */
    LOCAL_FUNC
    FT_Error  TT_CharMap_Free( TT_Face        face,
                               TT_CMapTable*  cmap )
    {
      FT_Memory  memory;
  
  
      if ( !cmap )
        return TT_Err_Ok;
  
      memory = face->root.driver->root.memory;
  
      switch ( cmap->format )
      {
      case 0:
        FREE( cmap->c.cmap0.glyphIdArray );
        break;
  
      case 2:
        FREE( cmap->c.cmap2.subHeaderKeys );
        FREE( cmap->c.cmap2.subHeaders );
        FREE( cmap->c.cmap2.glyphIdArray );
        break;
  
      case 4:
        FREE( cmap->c.cmap4.segments );
        FREE( cmap->c.cmap4.glyphIdArray );
        cmap->c.cmap4.segCountX2 = 0;
        break;
  
      case 6:
        FREE( cmap->c.cmap6.glyphIdArray );
        cmap->c.cmap6.entryCount = 0;
        break;
  
      default:
        /* invalid table format, do nothing */
        ;
      }
  
      cmap->loaded = FALSE;
      return TT_Err_Ok;
    }
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    code_to_index0                                                     */
    /*                                                                       */
    /* <Description>                                                         */
    /*    Converts the character code into a glyph index.  Uses format 0.    */
    /*    `charCode' must be in the range 0x00-0xFF (otherwise 0 is          */
    /*    returned).                                                         */
    /*                                                                       */
    /* <Input>                                                               */
    /*    charCode :: The wanted character code.                             */
    /*    cmap0    :: A pointer to a cmap table in format 0.                 */
    /*                                                                       */
    /* <Return>                                                              */
    /*    Glyph index into the glyphs array.  0 if the glyph does not exist. */
    /*                                                                       */
    static
    FT_UInt  code_to_index0( TT_CMapTable*  cmap,
                             FT_ULong       charCode )
    {
      TT_CMap0*  cmap0 = &cmap->c.cmap0;
  
  
      return ( charCode <= 0xFF ? cmap0->glyphIdArray[charCode] : 0 );
    }
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    code_to_index2                                                     */
    /*                                                                       */
    /* <Description>                                                         */
    /*    Converts the character code into a glyph index.  Uses format 2.    */
    /*                                                                       */
    /* <Input>                                                               */
    /*    charCode :: The wanted character code.                             */
    /*    cmap2    :: A pointer to a cmap table in format 2.                 */
    /*                                                                       */
    /* <Return>                                                              */
    /*    Glyph index into the glyphs array.  0 if the glyph does not exist. */
    /*                                                                       */
    static
    FT_UInt  code_to_index2( TT_CMapTable*  cmap,
                             FT_ULong       charCode )
    {
      FT_UInt             result, index1, offset;
      FT_UInt             char_lo;
      FT_ULong            char_hi;
      TT_CMap2SubHeader*  sh2;
      TT_CMap2*           cmap2;
  
  
      cmap2   = &cmap->c.cmap2;
      result  = 0;
      char_lo = (FT_UInt)( charCode & 0xFF );
      char_hi = charCode >> 8;
  
      if ( char_hi == 0 )
      {
        /* an 8-bit character code -- we use the subHeader 0 in this case */
        /* to test whether the character code is in the charmap           */
        if ( cmap2->subHeaderKeys[char_lo] == 0 )
          result = cmap2->glyphIdArray[char_lo];
      }
      else
      {
        /* a 16-bit character code */
        index1 = cmap2->subHeaderKeys[char_hi & 0xFF];
        if ( index1 )
        {
          sh2      = cmap2->subHeaders + index1;
          char_lo -= sh2->firstCode;
  
          if ( char_lo < sh2->entryCount )
          {
            offset = sh2->idRangeOffset / 2 + char_lo;
            if ( offset < cmap2->numGlyphId )
            {
              result = cmap2->glyphIdArray[offset];
              if ( result )
                result = ( result + sh2->idDelta ) & 0xFFFF;
            }
          }
        }
      }
  
      return result;
    }
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    code_to_index4                                                     */
    /*                                                                       */
    /* <Description>                                                         */
    /*    Converts the character code into a glyph index.  Uses format 4.    */
    /*                                                                       */
    /* <Input>                                                               */
    /*    charCode :: The wanted character code.                             */
    /*    cmap4    :: A pointer to a cmap table in format 4.                 */
    /*                                                                       */
    /* <Return>                                                              */
    /*    Glyph index into the glyphs array.  0 if the glyph does not exist. */
    /*                                                                       */
    static
    FT_UInt  code_to_index4( TT_CMapTable*  cmap,
                             FT_ULong       charCode )
    {
      FT_UInt          result, index1, segCount;
      TT_CMap4*        cmap4;
      TT_CMap4Segment  *seg4, *limit;
  
  
      cmap4    = &cmap->c.cmap4;
      result   = 0;
      segCount = cmap4->segCountX2 / 2;
      seg4     = cmap4->segments;
      limit    = seg4 + segCount;
  
      /* check against the last segment */
      seg4 = cmap4->last_segment;
  
      /* the following is equivalent to performing two tests, as in         */
      /*                                                                    */
      /*  if ( charCode >= seg4->startCount && charCode <= seg4->endCount ) */
      /*                                                                    */
      /* Yes, that's a bit strange, but it's faster, and the idea behind    */
      /* the cache is to significantly speed up charcode to glyph index     */
      /* conversion.                                                        */
  
      if ( (FT_ULong)(charCode       - seg4->startCount) <
           (FT_ULong)(seg4->endCount - seg4->startCount) )
        goto Found;
  
      for ( seg4 = cmap4->segments; seg4 < limit; seg4++ )
      {
        /* the ranges are sorted in increasing order.  If we are out of */
        /* the range here, the char code isn't in the charmap, so exit. */
  
        if ( charCode > seg4->endCount )
          continue;
  
        if ( charCode >= seg4->startCount )
          goto Found;
      }
      return 0;
  
   Found:
      cmap4->last_segment = seg4;
  
      /* if the idRangeOffset is 0, we can compute the glyph index */
      /* directly                                                  */
  
      if ( seg4->idRangeOffset == 0 )
        result = ( charCode + seg4->idDelta ) & 0xFFFF;
      else
      {
        /* otherwise, we must use the glyphIdArray to do it */
        index1 = seg4->idRangeOffset / 2
                 + ( charCode - seg4->startCount )
                 + ( seg4 - cmap4->segments )
                 - segCount;
  
        if ( index1 < cmap4->numGlyphId       &&
             cmap4->glyphIdArray[index1] != 0 )
          result = ( cmap4->glyphIdArray[index1] + seg4->idDelta ) & 0xFFFF;
      }
  
      return result;
    }
  
  
    /*************************************************************************/
    /*                                                                       */
    /* <Function>                                                            */
    /*    code_to_index6                                                     */
    /*                                                                       */
    /* <Description>                                                         */
    /*    Converts the character code into a glyph index.  Uses format 6.    */
    /*                                                                       */
    /* <Input>                                                               */
    /*    charCode :: The wanted character code.                             */
    /*    cmap6    :: A pointer to a cmap table in format 6.                 */
    /*                                                                       */
    /* <Return>                                                              */
    /*    Glyph index into the glyphs array.  0 if the glyph does not exist. */
    /*                                                                       */
    static
    FT_UInt  code_to_index6( TT_CMapTable*  cmap,
                             FT_ULong       charCode )
    {
      TT_CMap6*  cmap6;
      FT_UInt    result = 0;
  
  
      cmap6     = &cmap->c.cmap6;
      result    = 0;
      charCode -= cmap6->firstCode;
  
      if ( charCode < cmap6->entryCount )
        result =  cmap6->glyphIdArray[charCode];
  
      return result;
    }
  
  
  /* END */
  

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