t1decode.c

一个Xpdf应用的例子

          break;

        case op_seac:
          /* return immediately after the processing */
          return t1operator_seac( decoder, top[0], top[1],
                                           top[2], top[3], top[4] );

        case op_sbw:
          FT_TRACE4(( " sbw" ));

          builder->left_bearing.x += top[0];
          builder->left_bearing.y += top[1];
          builder->advance.x       = top[2];
          builder->advance.y       = top[3];

          builder->last.x = x = builder->pos_x + top[0];
          builder->last.y = y = builder->pos_y + top[1];

          /* the `metrics_only' indicates that we only want to compute */
          /* the glyph's metrics (lsb + advance width), not load the   */
          /* rest of it; so exit immediately                           */
          if ( builder->metrics_only )
            return PSaux_Err_Ok;

          break;

        case op_closepath:
          FT_TRACE4(( " closepath" ));

          close_contour( builder );
          builder->path_begun = 0;
          break;

        case op_hlineto:
          FT_TRACE4(( " hlineto" ));

          if ( start_point( builder, x, y ) )
            goto Memory_Error;

          x += top[0];
          goto Add_Line;

        case op_hmoveto:
          FT_TRACE4(( " hmoveto" ));

          x += top[0];
          if ( !decoder->flex_state )
            builder->path_begun = 0;
          break;

        case op_hvcurveto:
          FT_TRACE4(( " hvcurveto" ));

          if ( start_point( builder, x, y ) ||
               check_points( builder, 3 )   )
            goto Memory_Error;

          x += top[0];
          add_point( builder, x, y, 0 );
          x += top[1];
          y += top[2];
          add_point( builder, x, y, 0 );
          y += top[3];
          add_point( builder, x, y, 1 );
          break;

        case op_rlineto:
          FT_TRACE4(( " rlineto" ));

          if ( start_point( builder, x, y ) )
            goto Memory_Error;

          x += top[0];
          y += top[1];

        Add_Line:
          if ( add_point1( builder, x, y ) )
            goto Memory_Error;
          break;

        case op_rmoveto:
          FT_TRACE4(( " rmoveto" ));

          x += top[0];
          y += top[1];
          if ( !decoder->flex_state )
            builder->path_begun = 0;
          break;

        case op_rrcurveto:
          FT_TRACE4(( " rcurveto" ));

          if ( start_point( builder, x, y ) ||
               check_points( builder, 3 )   )
            goto Memory_Error;

          x += top[0];
          y += top[1];
          add_point( builder, x, y, 0 );

          x += top[2];
          y += top[3];
          add_point( builder, x, y, 0 );

          x += top[4];
          y += top[5];
          add_point( builder, x, y, 1 );
          break;

        case op_vhcurveto:
          FT_TRACE4(( " vhcurveto" ));

          if ( start_point( builder, x, y ) ||
               check_points( builder, 3 )   )
            goto Memory_Error;

          y += top[0];
          add_point( builder, x, y, 0 );
          x += top[1];
          y += top[2];
          add_point( builder, x, y, 0 );
          x += top[3];
          add_point( builder, x, y, 1 );
          break;

        case op_vlineto:
          FT_TRACE4(( " vlineto" ));

          if ( start_point( builder, x, y ) )
            goto Memory_Error;

          y += top[0];
          goto Add_Line;

        case op_vmoveto:
          FT_TRACE4(( " vmoveto" ));

          y += top[0];
          if ( !decoder->flex_state )
            builder->path_begun = 0;
          break;

        case op_div:
          FT_TRACE4(( " div" ));

          if ( top[1] )
          {
            *top = top[0] / top[1];
            ++top;
          }
          else
          {
            FT_ERROR(( "T1_Decoder_Parse_CharStrings: division by 0\n" ));
            goto Syntax_Error;
          }
          break;

        case op_callsubr:
          {
            FT_Int  index;


            FT_TRACE4(( " callsubr" ));

            index = top[0];
            if ( index < 0 || index >= (FT_Int)decoder->num_subrs )
            {
              FT_ERROR(( "T1_Decoder_Parse_CharStrings: "
                         "invalid subrs index\n" ));
              goto Syntax_Error;
            }

            if ( zone - decoder->zones >= T1_MAX_SUBRS_CALLS )
            {
              FT_ERROR(( "T1_Decoder_Parse_CharStrings: "
                         "too many nested subrs\n" ));
              goto Syntax_Error;
            }

            zone->cursor = ip;  /* save current instruction pointer */

            zone++;

            /* The Type 1 driver stores subroutines without the seed bytes. */
            /* The CID driver stores subroutines with seed bytes.  This     */
            /* case is taken care of when decoder->subrs_len == 0.          */
            zone->base = decoder->subrs[index];

            if ( decoder->subrs_len )
              zone->limit = zone->base + decoder->subrs_len[index];
            else
            {
              /* We are using subroutines from a CID font.  We must adjust */
              /* for the seed bytes.                                       */
              zone->base  += ( decoder->lenIV >= 0 ? decoder->lenIV : 0 );
              zone->limit  = decoder->subrs[index + 1];
            }

            zone->cursor = zone->base;

            if ( !zone->base )
            {
              FT_ERROR(( "T1_Decoder_Parse_CharStrings: "
                         "invoking empty subrs!\n" ));
              goto Syntax_Error;
            }

            decoder->zone = zone;
            ip            = zone->base;
            limit         = zone->limit;
            break;
          }

        case op_pop:
          FT_TRACE4(( " pop" ));

          /* theoretically, the arguments are already on the stack */
          top++;
          break;

        case op_return:
          FT_TRACE4(( " return" ));

          if ( zone <= decoder->zones )
          {
            FT_ERROR(( "T1_Decoder_Parse_CharStrings: unexpected return\n" ));
            goto Syntax_Error;
          }

          zone--;
          ip            = zone->cursor;
          limit         = zone->limit;
          decoder->zone = zone;
          break;

        case op_dotsection:
          FT_TRACE4(( " dotsection" ));

          break;

        case op_hstem:
          FT_TRACE4(( " hstem" ));
          
          /* record horizontal hint */
          if ( hinter )
          {
            /* top[0] += builder->left_bearing.y; */
            hinter->stem( hinter->hints, 1, top );
          }

          break;

        case op_hstem3:
          FT_TRACE4(( " hstem3" ));

          /* record horizontal counter-controlled hints */
          if ( hinter )
            hinter->stem3( hinter->hints, 1, top );
                           
          break;

        case op_vstem:
          FT_TRACE4(( " vstem" ));

          /* record vertical  hint */
          if ( hinter )
          {
            top[0] += orig_x;
            hinter->stem( hinter->hints, 0, top );
          }

          break;

        case op_vstem3:
          FT_TRACE4(( " vstem3" ));

          /* record vertical counter-controlled hints */
          if ( hinter )
          {
            FT_Pos  dx = orig_x;
            
            top[0] += dx;
            top[2] += dx;
            top[4] += dx;
            hinter->stem3( hinter->hints, 0, top );
          }
          break;

        case op_setcurrentpoint:
          FT_TRACE4(( " setcurrentpoint" ));

          FT_ERROR(( "T1_Decoder_Parse_CharStrings: " ));
          FT_ERROR(( "unexpected `setcurrentpoint'\n" ));
          goto Syntax_Error;

        default:
          FT_ERROR(( "T1_Decoder_Parse_CharStrings: "
                     "unhandled opcode %d\n", op ));
          goto Syntax_Error;
        }

        decoder->top = top;

      } /* general operator processing */

    } /* while ip < limit */

    FT_TRACE4(( "..end..\n\n" ));

    return error;

  Syntax_Error:
    return PSaux_Err_Syntax_Error;

  Stack_Underflow:
    return PSaux_Err_Stack_Underflow;

  Memory_Error:
    return builder->error;
  }


  /* parse a single Type 1 glyph */
  FT_LOCAL_DEF FT_Error
  T1_Decoder_Parse_Glyph( T1_Decoder*  decoder,
                          FT_UInt      glyph )
  {
    return decoder->parse_callback( decoder, glyph );
  }


  /* initialise T1 decoder */
  FT_LOCAL_DEF FT_Error
  T1_Decoder_Init( T1_Decoder*          decoder,
                   FT_Face              face,
                   FT_Size              size,
                   FT_GlyphSlot         slot,
                   FT_Byte**            glyph_names,
                   T1_Blend*            blend,
                   FT_Bool              hinting,
                   T1_Decoder_Callback  parse_callback )
  {
    MEM_Set( decoder, 0, sizeof ( *decoder ) );

    /* retrieve PSNames interface from list of current modules */
    {
      PSNames_Interface*  psnames = 0;


      psnames = (PSNames_Interface*)FT_Get_Module_Interface(
                   FT_FACE_LIBRARY(face), "psnames" );
      if ( !psnames )
      {
        FT_ERROR(( "T1_Decoder_Init: " ));
        FT_ERROR(( "the `psnames' module is not available\n" ));
        return PSaux_Err_Unimplemented_Feature;
      }

      decoder->psnames = psnames;
    }
    T1_Builder_Init( &decoder->builder, face, size, slot, hinting );

    decoder->num_glyphs     = face->num_glyphs;
    decoder->glyph_names    = glyph_names;
    decoder->blend          = blend;
    decoder->parse_callback = parse_callback;

    decoder->funcs       = t1_decoder_funcs;

    return 0;
  }


  /* finalize T1 decoder */
  FT_LOCAL_DEF void
  T1_Decoder_Done( T1_Decoder*  decoder )
  {
    T1_Builder_Done( &decoder->builder );
  }


/* END */