path: root/tests/freetype/src/sfnt/ttsbit0.c

/***************************************************************************/
/*                                                                         */
/*  ttsbit0.c                                                              */
/*                                                                         */
/*    TrueType and OpenType embedded bitmap support (body).                */
/*    This is a heap-optimized version.                                    */
/*                                                                         */
/*  Copyright 2005, 2006, 2007, 2008, 2009 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.                                        */
/*                                                                         */
/***************************************************************************/


/* This file is included by ttsbit.c */


#include <ft2build.h>
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_TRUETYPE_TAGS_H
#include "ttsbit.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_ttsbit


  FT_LOCAL_DEF( FT_Error )
  tt_face_load_eblc( TT_Face    face,
                     FT_Stream  stream )
  {
    FT_Error  error = SFNT_Err_Ok;
    FT_Fixed  version;
    FT_ULong  num_strikes, table_size;
    FT_Byte*  p;
    FT_Byte*  p_limit;
    FT_UInt   count;


    face->sbit_num_strikes = 0;

    /* this table is optional */
    error = face->goto_table( face, TTAG_EBLC, stream, &table_size );
    if ( error )
      error = face->goto_table( face, TTAG_bloc, stream, &table_size );
    if ( error )
      goto Exit;

    if ( table_size < 8 )
    {
      FT_ERROR(( "tt_face_load_sbit_strikes: table too short\n" ));
      error = SFNT_Err_Invalid_File_Format;
      goto Exit;
    }

    if ( FT_FRAME_EXTRACT( table_size, face->sbit_table ) )
      goto Exit;

    face->sbit_table_size = table_size;

    p       = face->sbit_table;
    p_limit = p + table_size;

    version     = FT_NEXT_ULONG( p );
    num_strikes = FT_NEXT_ULONG( p );

    if ( version != 0x00020000UL || num_strikes >= 0x10000UL )
    {
      FT_ERROR(( "tt_face_load_sbit_strikes: invalid table version\n" ));
      error = SFNT_Err_Invalid_File_Format;
      goto Fail;
    }

    /*
     *  Count the number of strikes available in the table.  We are a bit
     *  paranoid there and don't trust the data.
     */
    count = (FT_UInt)num_strikes;
    if ( 8 + 48UL * count > table_size )
      count = (FT_UInt)( ( p_limit - p ) / 48 );

    face->sbit_num_strikes = count;

    FT_TRACE3(( "sbit_num_strikes: %u\n", count ));
  Exit:
    return error;

  Fail:
    FT_FRAME_RELEASE( face->sbit_table );
    face->sbit_table_size = 0;
    goto Exit;
  }


  FT_LOCAL_DEF( void )
  tt_face_free_eblc( TT_Face  face )
  {
    FT_Stream  stream = face->root.stream;


    FT_FRAME_RELEASE( face->sbit_table );
    face->sbit_table_size  = 0;
    face->sbit_num_strikes = 0;
  }


  FT_LOCAL_DEF( FT_Error )
  tt_face_set_sbit_strike( TT_Face          face,
                           FT_Size_Request  req,
                           FT_ULong*        astrike_index )
  {
    return FT_Match_Size( (FT_Face)face, req, 0, astrike_index );
  }


  FT_LOCAL_DEF( FT_Error )
  tt_face_load_strike_metrics( TT_Face           face,
                               FT_ULong          strike_index,
                               FT_Size_Metrics*  metrics )
  {
    FT_Byte*  strike;


    if ( strike_index >= (FT_ULong)face->sbit_num_strikes )
      return SFNT_Err_Invalid_Argument;

    strike = face->sbit_table + 8 + strike_index * 48;

    metrics->x_ppem = (FT_UShort)strike[44];
    metrics->y_ppem = (FT_UShort)strike[45];

    metrics->ascender  = (FT_Char)strike[16] << 6;  /* hori.ascender  */
    metrics->descender = (FT_Char)strike[17] << 6;  /* hori.descender */
    metrics->height    = metrics->ascender - metrics->descender;

    /* XXX: Is this correct? */
    metrics->max_advance = ( (FT_Char)strike[22] + /* min_origin_SB  */
                                      strike[18] + /* max_width      */
                             (FT_Char)strike[23]   /* min_advance_SB */
                                                 ) <<