/***************************************************************************/
/*                                                                         */
/*  cidgload.c                                                             */
/*                                                                         */
/*    CID-keyed Type1 Glyph Loader (body).                                 */
/*                                                                         */
/*  Copyright 1996-2001, 2002, 2003, 2004, 2005, 2006 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 "cidload.h"
#include "cidgload.h"
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_OUTLINE_H

#include "ciderrs.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_cidgload


  FT_CALLBACK_DEF( FT_Error )
  cid_load_glyph( T1_Decoder  decoder,
                  FT_UInt     glyph_index )
  {
    CID_Face       face = (CID_Face)decoder->builder.face;
    CID_FaceInfo   cid  = &face->cid;
    FT_Byte*       p;
    FT_UInt        fd_select;
    FT_Stream      stream = face->cid_stream;
    FT_Error       error  = 0;
    FT_Byte*       charstring = 0;
    FT_Memory      memory = face->root.memory;
    FT_ULong       glyph_length = 0;
    PSAux_Service  psaux = (PSAux_Service)face->psaux;


#ifdef FT_CONFIG_OPTION_INCREMENTAL

    /* For incremental fonts get the character data using */
    /* the callback function.                             */
    if ( face->root.internal->incremental_interface )
    {
      FT_Data  glyph_data;


      error = face->root.internal->incremental_interface->funcs->get_glyph_data(
                face->root.internal->incremental_interface->object,
                glyph_index,
                &glyph_data );
      if ( error )
        goto Exit;

      p         = (FT_Byte*)glyph_data.pointer;
      fd_select = (FT_UInt)cid_get_offset( &p, (FT_Byte)cid->fd_bytes );

      if ( glyph_data.length != 0 )
      {
        glyph_length = glyph_data.length - cid->fd_bytes;
        FT_ALLOC( charstring, glyph_length );
        if ( !error )
          ft_memcpy( charstring, glyph_data.pointer + cid->fd_bytes,
                     glyph_length );
      }

      face->root.internal->incremental_interface->funcs->free_glyph_data(
                face->root.internal->incremental_interface->object,
                &glyph_data );

      if ( error )
        goto Exit;
    }

    else

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

    /* For ordinary fonts read the CID font dictionary index */
    /* and charstring offset from the CIDMap.                */
    {
      FT_UInt   entry_len = cid->fd_bytes + cid->gd_bytes;
      FT_ULong  off1;


      if ( FT_STREAM_SEEK( cid->data_offset + cid->cidmap_offset +
                           glyph_index * entry_len )               ||
           FT_FRAME_ENTER( 2 * entry_len )                         )
        goto Exit;

      p            = (FT_Byte*)stream->cursor;
      fd_select    = (FT_UInt) cid_get_offset( &p, (FT_Byte)cid->fd_bytes );
      off1         = (FT_ULong)cid_get_offset( &p, (FT_Byte)cid->gd_bytes );
      p           += cid->fd_bytes;
      glyph_length = cid_get_offset( &p, (FT_Byte)cid->gd_bytes ) - off1;
      FT_FRAME_EXIT();

      if ( glyph_length == 0 )
        goto Exit;
      if ( FT_ALLOC( charstring, glyph_length ) )
        goto Exit;
      if ( FT_STREAM_READ_AT( cid->data_offset + off1,
                              charstring, glyph_length ) )
        goto Exit;
    }

    /* Now set up the subrs array and parse the charstrings. */
    {
      CID_FaceDict  dict;
      CID_Subrs     cid_subrs = face->subrs + fd_select;
      FT_Int        cs_offset;


      /* Set up subrs */
      decoder->num_subrs = cid_subrs->num_subrs;
      decoder->subrs     = cid_subrs->code;
      decoder->subrs_len = 0;

      /* Set up font matrix */
      dict                 = cid->font_dicts + fd_select;

      decoder->font_matrix = dict->font_matrix;
      decoder->font_offset = dict->font_offset;
      decoder->lenIV       = dict->private_dict.lenIV;

      /* Decode the charstring. */

      /* Adjustment for seed bytes. */
      cs_offset = ( decoder->lenIV >= 0 ? decoder->lenIV : 0 );

      /* Decrypt only if lenIV >= 0. */
      if ( decoder->lenIV >= 0 )
        psaux->t1_decrypt( charstring, glyph_length, 4330 );

      error = decoder->funcs.parse_charstrings(
                decoder, charstring + cs_offset,
                (FT_Int)glyph_length - cs_offset  );
    }

    FT_FREE( charstring );

#ifdef FT_CONFIG_OPTION_INCREMENTAL

    /* Incremental fonts can optionally override the metrics. */
    if ( !error                                                              &&
         face->root.internal->incremental_interface                          &&
         face->root.internal->incremental_interface->funcs->get_glyph_metrics )
    {
      FT_Incremental_MetricsRec  metrics;


      metrics.bearing_x = decoder->builder.left_bearing.x;
      metrics.bearing_y = decoder->builder.left_bearing.y;
      metrics.advance   = decoder->builder.advance.x;
      error = face->root.internal->incremental_interface->funcs->get_glyph_metrics(
                face->root.internal->incremental_interface->object,
                glyph_index, FALSE, &metrics );
      decoder->builder.left_bearing.x = metrics.bearing_x;
      decoder->builder.left_bearing.y = metrics.bearing_y;
      decoder->builder.advance.x      = metrics.advance;
      decoder->builder.advance.y      = 0;
    }

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

  Exit:
    return error;
  }


#if 0


  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/
  /**********                                                      *********/
  /**********                                                      *********/
  /**********            COMPUTE THE MAXIMUM ADVANCE WIDTH         *********/
  /**********                                                      *********/
  /**********    The following code is in charge of computing      *********/
  /**********    the maximum advance width of the font.  It        *********/
  /**********    quickly processes each glyph charstring to        *********/
  /**********    extract the value from either a `sbw' or `seac'   *********/
  /**********    operator.                                         *********/
  /**********                                                      *********/
  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/