pcfread.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/*  pcfread.c

    FreeType font driver for pcf fonts

  Copyright 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 by
  Francesco Zappa Nardelli

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/


#include <ft2build.h>

#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_OBJECTS_H

#include "pcf.h"
#include "pcfdrivr.h"
#include "pcfread.h"

#include "pcferror.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_pcfread


#if defined( FT_DEBUG_LEVEL_TRACE )
  static const char* const  tableNames[] =
  {
    "prop", "accl", "mtrcs", "bmps", "imtrcs",
    "enc", "swidth", "names", "accel"
  };
#endif


  static
  const FT_Frame_Field  pcf_toc_header[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  PCF_TocRec

    FT_FRAME_START( 8 ),
      FT_FRAME_ULONG_LE( version ),
      FT_FRAME_ULONG_LE( count ),
    FT_FRAME_END
  };


  static
  const FT_Frame_Field  pcf_table_header[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  PCF_TableRec

    FT_FRAME_START( 16  ),
      FT_FRAME_ULONG_LE( type ),
      FT_FRAME_ULONG_LE( format ),
      FT_FRAME_ULONG_LE( size ),
      FT_FRAME_ULONG_LE( offset ),
    FT_FRAME_END
  };


  static FT_Error
  pcf_read_TOC( FT_Stream  stream,
                PCF_Face   face )
  {
    FT_Error   error;
    PCF_Toc    toc = &face->toc;
    PCF_Table  tables;

    FT_Memory  memory = FT_FACE(face)->memory;
    FT_UInt    n;


    if ( FT_STREAM_SEEK ( 0 )                          ||
         FT_STREAM_READ_FIELDS ( pcf_toc_header, toc ) )
      return PCF_Err_Cannot_Open_Resource;

    if ( toc->version != PCF_FILE_VERSION                 ||
         toc->count   >  FT_ARRAY_MAX( face->toc.tables ) ||
         toc->count   == 0                                )
      return PCF_Err_Invalid_File_Format;

    if ( FT_NEW_ARRAY( face->toc.tables, toc->count ) )
      return PCF_Err_Out_Of_Memory;

    tables = face->toc.tables;
    for ( n = 0; n < toc->count; n++ )
    {
      if ( FT_STREAM_READ_FIELDS( pcf_table_header, tables ) )
        goto Exit;
      tables++;
    }

    /* Sort tables and check for overlaps.  Because they are almost      */
    /* always ordered already, an in-place bubble sort with simultaneous */
    /* boundary checking seems appropriate.                              */
    tables = face->toc.tables;

    for ( n = 0; n < toc->count - 1; n++ )
    {
      FT_UInt  i, have_change;


      have_change = 0;

      for ( i = 0; i < toc->count - 1 - n; i++ )
      {
        PCF_TableRec  tmp;


        if ( tables[i].offset > tables[i + 1].offset )
        {
          tmp           = tables[i];
          tables[i]     = tables[i + 1];
          tables[i + 1] = tmp;

          have_change = 1;
        }

        if ( ( tables[i].size   > tables[i + 1].offset )                  ||
             ( tables[i].offset > tables[i + 1].offset - tables[i].size ) )
          return PCF_Err_Invalid_Offset;
      }

      if ( !have_change )
        break;
    }

#if defined( FT_DEBUG_LEVEL_TRACE )

    {
      FT_UInt      i, j;
      const char*  name = "?";


      FT_TRACE4(( "pcf_read_TOC:\n" ));

      FT_TRACE4(( "  number of tables: %ld\n", face->toc.count ));

      tables = face->toc.tables;
      for ( i = 0; i < toc->count; i++ )
      {
        for ( j = 0; j < sizeof ( tableNames ) / sizeof ( tableNames[0] );
              j++ )
          if ( tables[i].type == (FT_UInt)( 1 << j ) )
            name = tableNames[j];

        FT_TRACE4(( "  %d: type=%s, format=0x%X, "
                    "size=%ld (0x%lX), offset=%ld (0x%lX)\n",
                    i, name,
                    tables[i].format,
                    tables[i].size, tables[i].size,
                    tables[i].offset, tables[i].offset ));
      }
    }

#endif

    return PCF_Err_Ok;

  Exit:
    FT_FREE( face->toc.tables );
    return error;
  }


#define PCF_METRIC_SIZE  12

  static
  const FT_Frame_Field  pcf_metric_header[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  PCF_MetricRec

    FT_FRAME_START( PCF_METRIC_SIZE ),
      FT_FRAME_SHORT_LE( leftSideBearing ),
      FT_FRAME_SHORT_LE( rightSideBearing ),
      FT_FRAME_SHORT_LE( characterWidth ),
      FT_FRAME_SHORT_LE( ascent ),
      FT_FRAME_SHORT_LE( descent ),
      FT_FRAME_SHORT_LE( attributes ),
    FT_FRAME_END
  };


  static
  const FT_Frame_Field  pcf_metric_msb_header[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  PCF_MetricRec

    FT_FRAME_START( PCF_METRIC_SIZE ),
      FT_FRAME_SHORT( leftSideBearing ),
      FT_FRAME_SHORT( rightSideBearing ),
      FT_FRAME_SHORT( characterWidth ),
      FT_FRAME_SHORT( ascent ),
      FT_FRAME_SHORT( descent ),
      FT_FRAME_SHORT( attributes ),
    FT_FRAME_END
  };


#define PCF_COMPRESSED_METRIC_SIZE  5

  static
  const FT_Frame_Field  pcf_compressed_metric_header[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  PCF_Compressed_MetricRec

    FT_FRAME_START( PCF_COMPRESSED_METRIC_SIZE ),
      FT_FRAME_BYTE( leftSideBearing ),
      FT_FRAME_BYTE( rightSideBearing ),
      FT_FRAME_BYTE( characterWidth ),
      FT_FRAME_BYTE( ascent ),
      FT_FRAME_BYTE( descent ),
    FT_FRAME_END
  };


  static FT_Error
  pcf_get_metric( FT_Stream   stream,
                  FT_ULong    format,
                  PCF_Metric  metric )
  {
    FT_Error  error = PCF_Err_Ok;


    if ( PCF_FORMAT_MATCH( format, PCF_DEFAULT_FORMAT ) )
    {
      const FT_Frame_Field*  fields;


      /* parsing normal metrics */
      fields = PCF_BYTE_ORDER( format ) == MSBFirst
               ? pcf_metric_msb_header
               : pcf_metric_header;

      /* the following sets `error' but doesn't return in case of failure */
      (void)FT_STREAM_READ_FIELDS( fields, metric );
    }
    else
    {
      PCF_Compressed_MetricRec  compr;


      /* parsing compressed metrics */
      if ( FT_STREAM_READ_FIELDS( pcf_compressed_metric_header, &compr ) )
        goto Exit;

      metric->leftSideBearing  = (FT_Short)( compr.leftSideBearing  - 0x80 );
      metric->rightSideBearing = (FT_Short)( compr.rightSideBearing - 0x80 );
      metric->characterWidth   = (FT_Short)( compr.characterWidth   - 0x80 );
      metric->ascent           = (FT_Short)( compr.ascent           - 0x80 );
      metric->descent          = (FT_Short)( compr.descent          - 0x80 );
      metric->attributes       = 0;
    }

  Exit:
    return error;
  }


  static FT_Error
  pcf_seek_to_table_type( FT_Stream  stream,
                          PCF_Table  tables,
                          FT_Int     ntables,
                          FT_ULong   type,
                          FT_ULong  *aformat,
                          FT_ULong  *asize )
  {
    FT_Error  error = PCF_Err_Invalid_File_Format;
    FT_Int    i;


    for ( i = 0; i < ntables; i++ )
      if ( tables[i].type == type )
      {
        if ( stream->pos > tables[i].offset )
        {
          error = PCF_Err_Invalid_Stream_Skip;
          goto Fail;
        }

        if ( FT_STREAM_SKIP( tables[i].offset - stream->pos ) )
        {
          error = PCF_Err_Invalid_Stream_Skip;
          goto Fail;
        }

        *asize   = tables[i].size;
        *aformat = tables[i].format;

        return PCF_Err_Ok;
      }

  Fail:
    *asize = 0;
    return error;
  }


  static FT_Bool
  pcf_has_table_type( PCF_Table  tables,
                      FT_Int     ntables,
                      FT_ULong   type )
  {
    FT_Int  i;


    for ( i = 0; i < ntables; i++ )
      if ( tables[i].type == type )
        return TRUE;

    return FALSE;
  }


#define PCF_PROPERTY_SIZE  9

  static
  const FT_Frame_Field  pcf_property_header[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  PCF_ParsePropertyRec

    FT_FRAME_START( PCF_PROPERTY_SIZE ),
      FT_FRAME_LONG_LE( name ),
      FT_FRAME_BYTE   ( isString ),
      FT_FRAME_LONG_LE( value ),
    FT_FRAME_END
  };


  static
  const FT_Frame_Field  pcf_property_msb_header[] =
  {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  PCF_ParsePropertyRec

    FT_FRAME_START( PCF_PROPERTY_SIZE ),
      FT_FRAME_LONG( name ),
      FT_FRAME_BYTE( isString ),
      FT_FRAME_LONG( value ),
    FT_FRAME_END
  };


  FT_LOCAL_DEF( PCF_Property )
  pcf_find_property( PCF_Face          face,
                     const FT_String*  prop )
  {
    PCF_Property  properties = face->properties;
    FT_Bool       found      = 0;
    int           i;


    for ( i = 0 ; i < face->nprops && !found; i++ )
    {
      if ( !ft_strcmp( properties[i].name, prop ) )
        found = 1;
    }

    if ( found )
      return properties + i - 1;
    else
      return NULL;
  }


  static FT_Error
  pcf_get_properties( FT_Stream  stream,
                      PCF_Face   face )
  {
    PCF_ParseProperty  props      = 0;
    PCF_Property       properties;
    FT_UInt            nprops, i;
    FT_ULong           format, size;
    FT_Error           error;
    FT_Memory          memory     = FT_FACE(face)->memory;
    FT_ULong           string_size;
    FT_String*         strings    = 0;


    error = pcf_seek_to_table_type( stream,
                                    face->toc.tables,
                                    face->toc.count,
                                    PCF_PROPERTIES,
                                    &format,
                                    &size );
    if ( error )
      goto Bail;

    if ( FT_READ_ULONG_LE( format ) )
      goto Bail;

    FT_TRACE4(( "pcf_get_properties:\n" ));