/***************************************************************************/

/*                                                                         */

/*  ttmtx.c                                                                */

/*                                                                         */

/*    Load the metrics tables common to TTF and OTF fonts (body).          */

/*                                                                         */

/*  Copyright 2006-2017 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

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

#include FT_SERVICE_METRICS_VARIATIONS_H

#endif

#include "ttmtx.h"

#include "sferrors.h"

  /* IMPORTANT: The TT_HoriHeader and TT_VertHeader structures should   */

  /*            be identical except for the names of their fields,      */

  /*            which are different.                                    */

  /*                                                                    */

  /*            This ensures that `tt_face_load_hmtx' is able to read   */

  /*            both the horizontal and vertical headers.               */

  /*************************************************************************/

  /*                                                                       */

  /* 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

  /*************************************************************************/

  /*                                                                       */

  /* <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.                             */

  /*                                                                       */

  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;

  }

  /*************************************************************************/

  /*                                                                       */

  /* <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;

    static 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>                                                         */

  /*    Return the horizontal or vertical metrics in font units for a      */

  /*    given glyph.  The values are the left side bearing (top side       */

  /*    bearing for vertical metrics) and advance width (advance height    */

  /*    for vertical metrics).                                             */

  /*                                                                       */

  /* <Input>                                                               */

  /*    face     :: A pointer to the TrueType face structure.              */

  /*                                                                       */

  /*    vertical :: If set to TRUE, get vertical metrics.                  */

  /*                                                                       */

  /*    gindex   :: The glyph index.                                       */

  /*                                                                       */

  /* <Output>                                                              */

  /*    abearing :: The bearing, either left side or top side.             */

  /*                                                                       */

  /*    aadvance :: The advance width or advance height, depending on      */

  /*                the `vertical' flag.                                   */

  /*                                                                       */

  FT_LOCAL_DEF( void )

  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;

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

    FT_Service_MetricsVariations  var =

      (FT_Service_MetricsVariations)face->var;

#endif

    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;

    }

#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT

    if ( var )

    {

      FT_Face  f = FT_FACE( face );

      FT_Int   a = (FT_Int)*aadvance;

      FT_Int   b = (FT_Int)*abearing;

      if ( vertical )

      {

        if ( var->vadvance_adjust )

          var->vadvance_adjust( f, gindex, &a );

        if ( var->tsb_adjust )

          var->tsb_adjust( f, gindex, &b );

      }

      else

      {

        if ( var->hadvance_adjust )

          var->hadvance_adjust( f, gindex, &a );

        if ( var->lsb_adjust )

          var->lsb_adjust( f, gindex, &b );

      }

      *aadvance = (FT_UShort)a;

      *abearing = (FT_Short)b;

    }

#endif

  }

/* END */