misc/libfreetype/src/sfnt/ttmtx.c
author nemo
Thu, 04 Apr 2013 08:10:59 -0400
changeset 8848 e9ebd63f8a03
parent 5172 88f2e05288ba
permissions -rw-r--r--
So. Some themes have objects that seem to be large natural extensions of the landscape. Masks allow maintaining that. Lemme know if it doesn't look good. If it doesn't, can still use for ice/bounce/indestructible. Indestructible bunker object for example.

/***************************************************************************/
/*                                                                         */
/*  ttmtx.c                                                                */
/*                                                                         */
/*    Load the metrics tables common to TTF and OTF fonts (body).          */
/*                                                                         */
/*  Copyright 2006-2009, 2011 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 FT_INTERNAL_STREAM_H
#include FT_TRUETYPE_TAGS_H
#include "ttmtx.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_ttmtx


  /*
   *  Unfortunately, we can't enable our memory optimizations if
   *  FT_CONFIG_OPTION_OLD_INTERNALS is defined.  This is because at least
   *  one rogue client (libXfont in the X.Org XServer) is directly accessing
   *  the metrics.
   */

  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_load_hmtx                                                  */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Load the `hmtx' or `vmtx' table into a face object.                */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face     :: A handle to the target face object.                    */
  /*                                                                       */
  /*    stream   :: The input stream.                                      */
  /*                                                                       */
  /*    vertical :: A boolean flag.  If set, load `vmtx'.                  */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
#ifndef FT_CONFIG_OPTION_OLD_INTERNALS

  FT_LOCAL_DEF( FT_Error )
  tt_face_load_hmtx( TT_Face    face,
                     FT_Stream  stream,
                     FT_Bool    vertical )
  {
    FT_Error   error;
    FT_ULong   tag, table_size;
    FT_ULong*  ptable_offset;
    FT_ULong*  ptable_size;


    if ( vertical )
    {
      tag           = TTAG_vmtx;
      ptable_offset = &face->vert_metrics_offset;
      ptable_size   = &face->vert_metrics_size;
    }
    else
    {
      tag           = TTAG_hmtx;
      ptable_offset = &face->horz_metrics_offset;
      ptable_size   = &face->horz_metrics_size;
    }

    error = face->goto_table( face, tag, stream, &table_size );
    if ( error )
      goto Fail;

    *ptable_size   = table_size;
    *ptable_offset = FT_STREAM_POS();

  Fail:
    return error;
  }

#else /* !FT_CONFIG_OPTION_OLD_INTERNALS */

  FT_LOCAL_DEF( FT_Error )
  tt_face_load_hmtx( TT_Face    face,
                     FT_Stream  stream,
                     FT_Bool    vertical )
  {
    FT_Error   error;
    FT_Memory  memory = stream->memory;

    FT_ULong   table_len;
    FT_Long    num_shorts, num_longs, num_shorts_checked;

    TT_LongMetrics*    longs;
    TT_ShortMetrics**  shorts;
    FT_Byte*           p;


    if ( vertical )
    {
      void*   lm = &face->vertical.long_metrics;
      void**  sm = &face->vertical.short_metrics;


      error = face->goto_table( face, TTAG_vmtx, stream, &table_len );
      if ( error )
        goto Fail;

      num_longs = face->vertical.number_Of_VMetrics;
      if ( (FT_ULong)num_longs > table_len / 4 )
        num_longs = (FT_Long)( table_len / 4 );

      face->vertical.number_Of_VMetrics = 0;

      longs  = (TT_LongMetrics*)lm;
      shorts = (TT_ShortMetrics**)sm;
    }
    else
    {
      void*   lm = &face->horizontal.long_metrics;
      void**  sm = &face->horizontal.short_metrics;


      error = face->goto_table( face, TTAG_hmtx, stream, &table_len );
      if ( error )
        goto Fail;

      num_longs = face->horizontal.number_Of_HMetrics;
      if ( (FT_ULong)num_longs > table_len / 4 )
        num_longs = (FT_Long)( table_len / 4 );

      face->horizontal.number_Of_HMetrics = 0;

      longs  = (TT_LongMetrics*)lm;
      shorts = (TT_ShortMetrics**)sm;
    }

    /* never trust derived values */

    num_shorts         = face->max_profile.numGlyphs - num_longs;
    num_shorts_checked = ( table_len - num_longs * 4L ) / 2;

    if ( num_shorts < 0 )
    {
      FT_TRACE0(( "tt_face_load_hmtx:"
                  " %cmtx has more metrics than glyphs.\n",
                  vertical ? 'v' : 'h' ));

      /* Adobe simply ignores this problem.  So we shall do the same. */
#if 0
      error = vertical ? SFNT_Err_Invalid_Vert_Metrics
                       : SFNT_Err_Invalid_Horiz_Metrics;
      goto Exit;
#else
      num_shorts = 0;
#endif
    }

    if ( FT_QNEW_ARRAY( *longs,  num_longs  ) ||
         FT_QNEW_ARRAY( *shorts, num_shorts ) )
      goto Fail;

    if ( FT_FRAME_ENTER( table_len ) )
      goto Fail;

    p = stream->cursor;

    {
      TT_LongMetrics  cur   = *longs;
      TT_LongMetrics  limit = cur + num_longs;


      for ( ; cur < limit; cur++ )
      {
        cur->advance = FT_NEXT_USHORT( p );
        cur->bearing = FT_NEXT_SHORT( p );
      }
    }

    /* do we have an inconsistent number of metric values? */
    {
      TT_ShortMetrics*  cur   = *shorts;
      TT_ShortMetrics*  limit = cur +
                                FT_MIN( num_shorts, num_shorts_checked );


      for ( ; cur < limit; cur++ )
        *cur = FT_NEXT_SHORT( p );

      /* We fill up the missing left side bearings with the     */
      /* last valid value.  Since this will occur for buggy CJK */
      /* fonts usually only, nothing serious will happen.       */
      if ( num_shorts > num_shorts_checked && num_shorts_checked > 0 )
      {
        FT_Short  val = (*shorts)[num_shorts_checked - 1];


        limit = *shorts + num_shorts;
        for ( ; cur < limit; cur++ )
          *cur = val;
      }
    }

    FT_FRAME_EXIT();

    if ( vertical )
      face->vertical.number_Of_VMetrics = (FT_UShort)num_longs;
    else
      face->horizontal.number_Of_HMetrics = (FT_UShort)num_longs;

  Fail:
    return error;
  }

#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_load_hhea                                                  */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Load the `hhea' or 'vhea' table into a face object.                */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face     :: A handle to the target face object.                    */
  /*                                                                       */
  /*    stream   :: The input stream.                                      */
  /*                                                                       */
  /*    vertical :: A boolean flag.  If set, load `vhea'.                  */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  tt_face_load_hhea( TT_Face    face,
                     FT_Stream  stream,
                     FT_Bool    vertical )
  {
    FT_Error        error;
    TT_HoriHeader*  header;

    const FT_Frame_Field  metrics_header_fields[] =
    {
#undef  FT_STRUCTURE
#define FT_STRUCTURE  TT_HoriHeader

      FT_FRAME_START( 36 ),
        FT_FRAME_ULONG ( Version ),
        FT_FRAME_SHORT ( Ascender ),
        FT_FRAME_SHORT ( Descender ),
        FT_FRAME_SHORT ( Line_Gap ),
        FT_FRAME_USHORT( advance_Width_Max ),
        FT_FRAME_SHORT ( min_Left_Side_Bearing ),
        FT_FRAME_SHORT ( min_Right_Side_Bearing ),
        FT_FRAME_SHORT ( xMax_Extent ),
        FT_FRAME_SHORT ( caret_Slope_Rise ),
        FT_FRAME_SHORT ( caret_Slope_Run ),
        FT_FRAME_SHORT ( caret_Offset ),
        FT_FRAME_SHORT ( Reserved[0] ),
        FT_FRAME_SHORT ( Reserved[1] ),
        FT_FRAME_SHORT ( Reserved[2] ),
        FT_FRAME_SHORT ( Reserved[3] ),
        FT_FRAME_SHORT ( metric_Data_Format ),
        FT_FRAME_USHORT( number_Of_HMetrics ),
      FT_FRAME_END
    };


    if ( vertical )
    {
      void  *v = &face->vertical;


      error = face->goto_table( face, TTAG_vhea, stream, 0 );
      if ( error )
        goto Fail;

      header = (TT_HoriHeader*)v;
    }
    else
    {
      error = face->goto_table( face, TTAG_hhea, stream, 0 );
      if ( error )
        goto Fail;

      header = &face->horizontal;
    }

    if ( FT_STREAM_READ_FIELDS( metrics_header_fields, header ) )
      goto Fail;

    FT_TRACE3(( "Ascender:          %5d\n", header->Ascender ));
    FT_TRACE3(( "Descender:         %5d\n", header->Descender ));
    FT_TRACE3(( "number_Of_Metrics: %5u\n", header->number_Of_HMetrics ));

    header->long_metrics  = NULL;
    header->short_metrics = NULL;

  Fail:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    tt_face_get_metrics                                                */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Returns the horizontal or vertical metrics in font units for a     */
  /*    given glyph.  The metrics are the left side bearing (resp. top     */
  /*    side bearing) and advance width (resp. advance height).            */
  /*                                                                       */
  /* <Input>                                                               */
  /*    header  :: A pointer to either the horizontal or vertical metrics  */
  /*               structure.                                              */
  /*                                                                       */
  /*    idx     :: The glyph index.                                        */
  /*                                                                       */
  /* <Output>                                                              */
  /*    bearing :: The bearing, either left side or top side.              */
  /*                                                                       */
  /*    advance :: The advance width resp. advance height.                 */
  /*                                                                       */
#ifndef FT_CONFIG_OPTION_OLD_INTERNALS

  FT_LOCAL_DEF( FT_Error )
  tt_face_get_metrics( TT_Face     face,
                       FT_Bool     vertical,
                       FT_UInt     gindex,
                       FT_Short   *abearing,
                       FT_UShort  *aadvance )
  {
    FT_Error        error;
    FT_Stream       stream = face->root.stream;
    TT_HoriHeader*  header;
    FT_ULong        table_pos, table_size, table_end;
    FT_UShort       k;


    if ( vertical )
    {
      void*  v = &face->vertical;


      header     = (TT_HoriHeader*)v;
      table_pos  = face->vert_metrics_offset;
      table_size = face->vert_metrics_size;
    }
    else
    {
      header     = &face->horizontal;
      table_pos  = face->horz_metrics_offset;
      table_size = face->horz_metrics_size;
    }

    table_end = table_pos + table_size;

    k = header->number_Of_HMetrics;

    if ( k > 0 )
    {
      if ( gindex < (FT_UInt)k )
      {
        table_pos += 4 * gindex;
        if ( table_pos + 4 > table_end )
          goto NoData;

        if ( FT_STREAM_SEEK( table_pos ) ||
             FT_READ_USHORT( *aadvance ) ||
             FT_READ_SHORT( *abearing )  )
          goto NoData;
      }
      else
      {
        table_pos += 4 * ( k - 1 );
        if ( table_pos + 4 > table_end )
          goto NoData;

        if ( FT_STREAM_SEEK( table_pos ) ||
             FT_READ_USHORT( *aadvance ) )
          goto NoData;

        table_pos += 4 + 2 * ( gindex - k );
        if ( table_pos + 2 > table_end )
          *abearing = 0;
        else
        {
          if ( !FT_STREAM_SEEK( table_pos ) )
            (void)FT_READ_SHORT( *abearing );
        }
      }
    }
    else
    {
    NoData:
      *abearing = 0;
      *aadvance = 0;
    }

    return SFNT_Err_Ok;
  }

#else /* !FT_CONFIG_OPTION_OLD_INTERNALS */

  FT_LOCAL_DEF( FT_Error )
  tt_face_get_metrics( TT_Face     face,
                       FT_Bool     vertical,
                       FT_UInt     gindex,
                       FT_Short*   abearing,
                       FT_UShort*  aadvance )
  {
    void*           v = &face->vertical;
    void*           h = &face->horizontal;
    TT_HoriHeader*  header = vertical ? (TT_HoriHeader*)v
                                      : (TT_HoriHeader*)h;
    TT_LongMetrics  longs_m;
    FT_UShort       k = header->number_Of_HMetrics;


    if ( k == 0                                         ||
         !header->long_metrics                          ||
         gindex >= (FT_UInt)face->max_profile.numGlyphs )
    {
      *abearing = *aadvance = 0;
      return SFNT_Err_Ok;
    }

    if ( gindex < (FT_UInt)k )
    {
      longs_m   = (TT_LongMetrics)header->long_metrics + gindex;
      *abearing = longs_m->bearing;
      *aadvance = longs_m->advance;
    }
    else
    {
      *abearing = ((TT_ShortMetrics*)header->short_metrics)[gindex - k];
      *aadvance = ((TT_LongMetrics)header->long_metrics)[k - 1].advance;
    }

    return SFNT_Err_Ok;
  }

#endif /* !FT_CONFIG_OPTION_OLD_INTERNALS */


/* END */