t1gload.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/***************************************************************************/
/*                                                                         */
/*  t1gload.c                                                              */
/*                                                                         */
/*    Type 1 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 "t1gload.h"
#include FT_INTERNAL_DEBUG_H
#include FT_INTERNAL_STREAM_H
#include FT_OUTLINE_H
#include FT_INTERNAL_POSTSCRIPT_AUX_H

#include "t1errors.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_t1gload


  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/
  /**********                                                      *********/
  /**********            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.                                         *********/
  /**********                                                      *********/
  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/


  FT_LOCAL_DEF( FT_Error )
  T1_Parse_Glyph_And_Get_Char_String( T1_Decoder  decoder,
                                      FT_UInt     glyph_index,
                                      FT_Data*    char_string )
  {
    T1_Face   face  = (T1_Face)decoder->builder.face;
    T1_Font   type1 = &face->type1;
    FT_Error  error = T1_Err_Ok;


    decoder->font_matrix = type1->font_matrix;
    decoder->font_offset = type1->font_offset;

#ifdef FT_CONFIG_OPTION_INCREMENTAL

    /* For incremental fonts get the character data using the */
    /* callback function.                                     */
    if ( face->root.internal->incremental_interface )
      error = face->root.internal->incremental_interface->funcs->get_glyph_data(
                face->root.internal->incremental_interface->object,
                glyph_index, char_string );
    else

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

    /* For ordinary fonts get the character data stored in the face record. */
    {
      char_string->pointer = type1->charstrings[glyph_index];
      char_string->length  = (FT_Int)type1->charstrings_len[glyph_index];
    }

    if ( !error )
      error = decoder->funcs.parse_charstrings(
                decoder, (FT_Byte*)char_string->pointer,
                char_string->length );

#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 */

    return error;
  }


  FT_CALLBACK_DEF( FT_Error )
  T1_Parse_Glyph( T1_Decoder  decoder,
                  FT_UInt     glyph_index )
  {
    FT_Data   glyph_data;
    FT_Error  error = T1_Parse_Glyph_And_Get_Char_String(
                        decoder, glyph_index, &glyph_data );


#ifdef FT_CONFIG_OPTION_INCREMENTAL

    if ( !error )
    {
      T1_Face  face = (T1_Face)decoder->builder.face;


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

#endif /* FT_CONFIG_OPTION_INCREMENTAL */

    return error;
  }


  FT_LOCAL_DEF( FT_Error )
  T1_Compute_Max_Advance( T1_Face  face,
                          FT_Pos*  max_advance )
  {
    FT_Error       error;
    T1_DecoderRec  decoder;
    FT_Int         glyph_index;
    T1_Font        type1 = &face->type1;
    PSAux_Service  psaux = (PSAux_Service)face->psaux;


    FT_ASSERT( ( face->len_buildchar == 0 ) == ( face->buildchar == NULL ) );

    *max_advance = 0;

    /* initialize load decoder */
    error = psaux->t1_decoder_funcs->init( &decoder,
                                           (FT_Face)face,
                                           0, /* size       */
                                           0, /* glyph slot */
                                           (FT_Byte**)type1->glyph_names,
                                           face->blend,
                                           0,
                                           FT_RENDER_MODE_NORMAL,
                                           T1_Parse_Glyph );
    if ( error )
      return error;

    decoder.builder.metrics_only = 1;
    decoder.builder.load_points  = 0;

    decoder.num_subrs     = type1->num_subrs;
    decoder.subrs         = type1->subrs;
    decoder.subrs_len     = type1->subrs_len;

    decoder.buildchar     = face->buildchar;
    decoder.len_buildchar = face->len_buildchar;

    *max_advance = 0;

    /* for each glyph, parse the glyph charstring and extract */
    /* the advance width                                      */
    for ( glyph_index = 0; glyph_index < type1->num_glyphs; glyph_index++ )
    {
      /* now get load the unscaled outline */
      error = T1_Parse_Glyph( &decoder, glyph_index );
      if ( glyph_index == 0 || decoder.builder.advance.x > *max_advance )
        *max_advance = decoder.builder.advance.x;

      /* ignore the error if one occurred - skip to next glyph */
    }

    psaux->t1_decoder_funcs->done( &decoder );

    return T1_Err_Ok;
  }


  FT_LOCAL_DEF( FT_Error )
  T1_Load_Glyph( T1_GlyphSlot  glyph,
                 T1_Size       size,
                 FT_UInt       glyph_index,
                 FT_Int32      load_flags )
  {
    FT_Error                error;
    T1_DecoderRec           decoder;