t1decode.c

奇趣公司比较新的qt/emd版本

/***************************************************************************/
/*                                                                         */
/*  t1decode.c                                                             */
/*                                                                         */
/*    PostScript Type 1 decoding routines (body).                          */
/*                                                                         */
/*  Copyright 2000-2001, 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 FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_POSTSCRIPT_HINTS_H
#include FT_OUTLINE_H

#include "t1decode.h"
#include "psobjs.h"

#include "psauxerr.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_t1decode


  typedef enum  T1_Operator_
  {
    op_none = 0,
    op_endchar,
    op_hsbw,
    op_seac,
    op_sbw,
    op_closepath,
    op_hlineto,
    op_hmoveto,
    op_hvcurveto,
    op_rlineto,
    op_rmoveto,
    op_rrcurveto,
    op_vhcurveto,
    op_vlineto,
    op_vmoveto,
    op_dotsection,
    op_hstem,
    op_hstem3,
    op_vstem,
    op_vstem3,
    op_div,
    op_callothersubr,
    op_callsubr,
    op_pop,
    op_return,
    op_setcurrentpoint,
    op_unknown15,

    op_max    /* never remove this one */

  } T1_Operator;


  static
  const FT_Int  t1_args_count[op_max] =
  {
    0, /* none */
    0, /* endchar */
    2, /* hsbw */
    5, /* seac */
    4, /* sbw */
    0, /* closepath */
    1, /* hlineto */
    1, /* hmoveto */
    4, /* hvcurveto */
    2, /* rlineto */
    2, /* rmoveto */
    6, /* rrcurveto */
    4, /* vhcurveto */
    1, /* vlineto */
    1, /* vmoveto */
    0, /* dotsection */
    2, /* hstem */
    6, /* hstem3 */
    2, /* vstem */
    6, /* vstem3 */
    2, /* div */
   -1, /* callothersubr */
    1, /* callsubr */
    0, /* pop */
    0, /* return */
    2, /* setcurrentpoint */
    2  /* opcode 15 (undocumented and obsolete) */
  };


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    t1_lookup_glyph_by_stdcharcode                                     */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Looks up a given glyph by its StandardEncoding charcode.  Used to  */
  /*    implement the SEAC Type 1 operator.                                */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face     :: The current face object.                               */
  /*                                                                       */
  /*    charcode :: The character code to look for.                        */
  /*                                                                       */
  /* <Return>                                                              */
  /*    A glyph index in the font face.  Returns -1 if the corresponding   */
  /*    glyph wasn't found.                                                */
  /*                                                                       */
  static FT_Int
  t1_lookup_glyph_by_stdcharcode( T1_Decoder  decoder,
                                  FT_Int      charcode )
  {
    FT_UInt             n;
    const FT_String*    glyph_name;
    FT_Service_PsCMaps  psnames = decoder->psnames;


    /* check range of standard char code */
    if ( charcode < 0 || charcode > 255 )
      return -1;

    glyph_name = psnames->adobe_std_strings(
                   psnames->adobe_std_encoding[charcode]);

    for ( n = 0; n < decoder->num_glyphs; n++ )
    {
      FT_String*  name = (FT_String*)decoder->glyph_names[n];


      if ( name && name[0] == glyph_name[0]  &&
           ft_strcmp( name, glyph_name ) == 0 )
        return n;
    }

    return -1;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    t1operator_seac                                                    */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Implements the `seac' Type 1 operator for a Type 1 decoder.        */
  /*                                                                       */
  /* <Input>                                                               */
  /*    decoder :: The current CID decoder.                                */
  /*                                                                       */
  /*    asb     :: The accent's side bearing.                              */
  /*                                                                       */
  /*    adx     :: The horizontal offset of the accent.                    */
  /*                                                                       */
  /*    ady     :: The vertical offset of the accent.                      */
  /*                                                                       */
  /*    bchar   :: The base character's StandardEncoding charcode.         */
  /*                                                                       */
  /*    achar   :: The accent character's StandardEncoding charcode.       */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  static FT_Error
  t1operator_seac( T1_Decoder  decoder,
                   FT_Pos      asb,
                   FT_Pos      adx,
                   FT_Pos      ady,
                   FT_Int      bchar,
                   FT_Int      achar )
  {
    FT_Error     error;
    FT_Int       bchar_index, achar_index;
#if 0
    FT_Int       n_base_points;
    FT_Outline*  base = decoder->builder.base;
#endif
    FT_Vector    left_bearing, advance;


    /* seac weirdness */
    adx += decoder->builder.left_bearing.x;

    /* `glyph_names' is set to 0 for CID fonts which do not */
    /* include an encoding.  How can we deal with these?    */
    if ( decoder->glyph_names == 0 )
    {
      FT_ERROR(( "t1operator_seac:" ));
      FT_ERROR(( " glyph names table not available in this font!\n" ));
      return PSaux_Err_Syntax_Error;
    }

    bchar_index = t1_lookup_glyph_by_stdcharcode( decoder, bchar );
    achar_index = t1_lookup_glyph_by_stdcharcode( decoder, achar );

    if ( bchar_index < 0 || achar_index < 0 )
    {
      FT_ERROR(( "t1operator_seac:" ));
      FT_ERROR(( " invalid seac character code arguments\n" ));
      return PSaux_Err_Syntax_Error;
    }

    /* if we are trying to load a composite glyph, do not load the */
    /* accent character and return the array of subglyphs.         */
    if ( decoder->builder.no_recurse )
    {
      FT_GlyphSlot    glyph  = (FT_GlyphSlot)decoder->builder.glyph;
      FT_GlyphLoader  loader = glyph->internal->loader;
      FT_SubGlyph     subg;


      /* reallocate subglyph array if necessary */
      error = FT_GlyphLoader_CheckSubGlyphs( loader, 2 );
      if ( error )
        goto Exit;

      subg = loader->current.subglyphs;

      /* subglyph 0 = base character */
      subg->index = bchar_index;
      subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES |
                    FT_SUBGLYPH_FLAG_USE_MY_METRICS;
      subg->arg1  = 0;
      subg->arg2  = 0;
      subg++;

      /* subglyph 1 = accent character */
      subg->index = achar_index;
      subg->flags = FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES;
      subg->arg1  = (FT_Int)( adx - asb );
      subg->arg2  = (FT_Int)ady;

      /* set up remaining glyph fields */
      glyph->num_subglyphs = 2;
      glyph->subglyphs     = loader->base.subglyphs;
      glyph->format        = FT_GLYPH_FORMAT_COMPOSITE;

      loader->current.num_subglyphs = 2;
      goto Exit;
    }

    /* First load `bchar' in builder */
    /* now load the unscaled outline */

    FT_GlyphLoader_Prepare( decoder->builder.loader );  /* prepare loader */

    error = t1_decoder_parse_glyph( decoder, bchar_index );
    if ( error )
      goto Exit;

    /* save the left bearing and width of the base character */
    /* as they will be erased by the next load.              */

    left_bearing = decoder->builder.left_bearing;
    advance      = decoder->builder.advance;

    decoder->builder.left_bearing.x = 0;
    decoder->builder.left_bearing.y = 0;

    decoder->builder.pos_x = adx - asb;
    decoder->builder.pos_y = ady;

    /* Now load `achar' on top of */
    /* the base outline           */
    error = t1_decoder_parse_glyph( decoder, achar_index );
    if ( error )
      goto Exit;

    /* restore the left side bearing and   */
    /* advance width of the base character */

    decoder->builder.left_bearing = left_bearing;
    decoder->builder.advance      = advance;

    decoder->builder.pos_x = 0;
    decoder->builder.pos_y = 0;

  Exit:
    return error;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    t1_decoder_parse_charstrings                                       */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Parses a given Type 1 charstrings program.                         */
  /*                                                                       */
  /* <Input>                                                               */
  /*    decoder         :: The current Type 1 decoder.                     */
  /*                                                                       */
  /*    charstring_base :: The base address of the charstring stream.      */
  /*                                                                       */
  /*    charstring_len  :: The length in bytes of the charstring stream.   */
  /*                                                                       */
  /* <Return>                                                              */
  /*    FreeType error code.  0 means success.                             */
  /*                                                                       */
  FT_LOCAL_DEF( FT_Error )
  t1_decoder_parse_charstrings( T1_Decoder  decoder,
                                FT_Byte*    charstring_base,
                                FT_UInt     charstring_len )
  {
    FT_Error         error;
    T1_Decoder_Zone  zone;
    FT_Byte*         ip;
    FT_Byte*         limit;
    T1_Builder       builder = &decoder->builder;
    FT_Pos           x, y, orig_x, orig_y;
    FT_Int           known_othersubr_result_cnt   = 0;
    FT_Int           unknown_othersubr_result_cnt = 0;

    T1_Hints_Funcs   hinter;


    /* we don't want to touch the source code -- use macro trick */
#define start_point    t1_builder_start_point
#define check_points   t1_builder_check_points
#define add_point      t1_builder_add_point
#define add_point1     t1_builder_add_point1
#define add_contour    t1_builder_add_contour
#define close_contour  t1_builder_close_contour

    /* First of all, initialize the decoder */
    decoder->top  = decoder->stack;
    decoder->zone = decoder->zones;
    zone          = decoder->zones;

    builder->parse_state = T1_Parse_Start;

    hinter = (T1_Hints_Funcs)builder->hints_funcs;

    /* a font that reads BuildCharArray without setting */
    /* its values first is buggy, but ...               */
    FT_ASSERT( ( decoder->len_buildchar == 0 ) ==
               ( decoder->buildchar == NULL ) );

    if ( decoder->len_buildchar > 0 )
      memset( &decoder->buildchar[0],
              0,
              sizeof( decoder->buildchar[0] ) *
                decoder->len_buildchar );

    FT_TRACE4(( "\nStart charstring\n" ));

    zone->base           = charstring_base;
    limit = zone->limit  = charstring_base + charstring_len;
    ip    = zone->cursor = zone->base;

    error = PSaux_Err_Ok;

    x = orig_x = builder->pos_x;
    y = orig_y = builder->pos_y;

    /* begin hints recording session, if any */
    if ( hinter )
      hinter->open( hinter->hints );

    /* now, execute loop */
    while ( ip < limit )
    {
      FT_Long*     top   = decoder->top;
      T1_Operator  op    = op_none;
      FT_Long      value = 0;


      FT_ASSERT( known_othersubr_result_cnt == 0   ||
                 unknown_othersubr_result_cnt == 0 );

      FT_TRACE5(( " (%d)", decoder->top - decoder->stack ));

      /*********************************************************************/
      /*                                                                   */
      /* Decode operator or operand                                        */
      /*                                                                   */
      /*                                                                   */

      /* first of all, decompress operator or value */
      switch ( *ip++ )
      {
      case 1:
        op = op_hstem;
        break;

      case 3:
        op = op_vstem;
        break;
      case 4:
        op = op_vmoveto;
        break;
      case 5:
        op = op_rlineto;
        break;
      case 6:
        op = op_hlineto;
        break;
      case 7:
        op = op_vlineto;
        break;
      case 8:
        op = op_rrcurveto;
        break;
      case 9:
        op = op_closepath;
        break;
      case 10:
        op = op_callsubr;
        break;
      case 11:
        op = op_return;
        break;

      case 13:
        op = op_hsbw;
        break;
      case 14:
        op = op_endchar;
        break;

      case 15:          /* undocumented, obsolete operator */
        op = op_unknown15;
        break;

      case 21:
        op = op_rmoveto;
        break;
      case 22:
        op = op_hmoveto;
        break;

      case 30:
        op = op_vhcurveto;
        break;
      case 31:
        op = op_hvcurveto;
        break;

      case 12:
        if ( ip > limit )
        {
          FT_ERROR(( "t1_decoder_parse_charstrings: "
                     "invalid escape (12+EOF)\n" ));
          goto Syntax_Error;
        }

        switch ( *ip++ )
        {
        case 0:
          op = op_dotsection;
          break;
        case 1:
          op = op_vstem3;
          break;
        case 2:
          op = op_hstem3;
          break;
        case 6:
          op = op_seac;
          break;
        case 7:
          op = op_sbw;
          break;
        case 12:
          op = op_div;
          break;
        case 16:
          op = op_callothersubr;
          break;
        case 17:
          op = op_pop;
          break;
        case 33:
          op = op_setcurrentpoint;
          break;