t1gload.c

Qt/Embedded是一个多平台的C++图形用户界面应用程序框架

/*******************************************************************
 *
 *  t1gload.c                                                   1.0
 *
 *    Type1 Glyph Loader.
 *
 *  Copyright 1996-1999 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 <t1gload.h>
#include <ftdebug.h>
#include <ftstream.h>

#undef  FT_COMPONENT
#define FT_COMPONENT  trace_t1gload

  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_max    /* never remove this one */

  } T1_Operator;

  static const T1_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 */
  };


  /**********************************************************************/
  /**********************************************************************/
  /**********************************************************************/
  /**********                                                   *********/
  /**********                                                   *********/
  /**********           GENERIC CHARSTRINGS PARSING             *********/
  /**********                                                   *********/
  /**********                                                   *********/
  /**********************************************************************/
  /**********************************************************************/
  /**********************************************************************/

/*********************************************************************
 *
 * <Function>
 *    T1_Init_Builder
 *
 * <Description>
 *    Initialise a given glyph builder.
 *
 * <Input>
 *    builder :: glyph builder to initialise
 *    face    :: current face object
 *    size    :: current size object
 *    glyph   :: current glyph object
 *
 *********************************************************************/

  LOCAL_FUNC
  void  T1_Init_Builder( T1_Builder*   builder,
                         T1_Face       face,
                         T1_Size       size,
                         T1_GlyphSlot  glyph )
  {
    builder->path_begun  = 0;
    builder->load_points = 1;

    builder->face   = face;
    builder->glyph  = glyph;
    builder->memory = face->root.memory;

    if (glyph)
    {
      builder->base         = glyph->root.outline;
      builder->max_points   = glyph->max_points;
      builder->max_contours = glyph->max_contours;
    }

    if (size)
    {
      builder->scale_x = size->root.metrics.x_scale;
      builder->scale_y = size->root.metrics.y_scale;
    }

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

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

    builder->base.n_points   = 0;
    builder->base.n_contours = 0;
    builder->current         = builder->base;
  }


/*********************************************************************
 *
 * <Function>
 *    T1_Done_Builder
 *
 * <Description>
 *    Finalise a given glyph builder. Its content can still be
 *    used after the call, but the function saves important information
 *    within the corresponding glyph slot.
 *
 * <Input>
 *    builder :: glyph builder to initialise
 *
 *********************************************************************/

  LOCAL_FUNC
  void T1_Done_Builder( T1_Builder*  builder )
  {
    T1_GlyphSlot  glyph = builder->glyph;

    if (glyph)
    {
      glyph->root.outline = builder->base;
      glyph->max_points   = builder->max_points;
      glyph->max_contours = builder->max_contours;
    }
  }



/*********************************************************************
 *
 * <Function>
 *    T1_Init_Decoder
 *
 * <Description>
 *    Initialise a given Type 1 decoder for parsing
 *
 * <Input>
 *    decoder :: Type 1 decoder to initialise
 *    funcs   :: hinter functions interface
 *
 *********************************************************************/

  EXPORT_FUNC
  void  T1_Init_Decoder( T1_Decoder* decoder )
  {
    decoder->top              = 0;
    decoder->zone             = 0;
    decoder->flex_state       = 0;
    decoder->num_flex_vectors = 0;

    /* Clear loader */
    MEM_Set( &decoder->builder, 0, sizeof(decoder->builder) );
  }


  /* check that there is enough room for "count" more points */
  static
  T1_Error  check_points( T1_Builder*  builder,
                          T1_Int       count )
  {
    FT_Outline*  base    = &builder->base;
    FT_Outline*  outline = &builder->current;

    if (!builder->load_points)
      return T1_Err_Ok;

    count += base->n_points + outline->n_points;
        
    /* realloc points table if necessary */
    if ( count >= builder->max_points )
    {
      T1_Error   error;
      FT_Memory  memory    = builder->memory;
      T1_Int     increment = outline->points - base->points;
      T1_Int     current   = builder->max_points;

      while ( builder->max_points < count )
        builder->max_points += 8;

      if ( REALLOC_ARRAY( base->points, current,
                          builder->max_points, T1_Vector )  ||
  
           REALLOC_ARRAY( base->tags, current,
                          builder->max_points, T1_Byte )    )
      {
        builder->error = error;
        return error;
      }
    
      outline->points = base->points + increment;
      outline->tags  = base->tags  + increment;
    }
    return T1_Err_Ok;
  }


  /* add a new point, do not check room */
  static
  void  add_point( T1_Builder*  builder,
                   FT_Pos       x,
                   FT_Pos       y,
                   FT_Byte      flag )
  {
    FT_Outline*  outline = &builder->current;

    if (builder->load_points)
    {
      FT_Vector*  point   = outline->points + outline->n_points;
      FT_Byte*    control = (FT_Byte*)outline->tags + outline->n_points;
      
      point->x = x;
      point->y = y;
      *control = ( flag ? FT_Curve_Tag_On : FT_Curve_Tag_Cubic );
      
      builder->last = *point;
    }
    
    outline->n_points++;
  }
    

  /* check room for a new on-curve point, then add it */
  static
  T1_Error  add_point1( T1_Builder*  builder,
                        FT_Pos       x,
                        FT_Pos       y )
  {
    T1_Error  error;
    
    error = check_points(builder,1);
    if (!error)
      add_point( builder, x, y, 1 );

    return error;
  }


  /* check room for a new contour, then add it */
  static
  T1_Error  add_contour( T1_Builder*  builder )
  {
    FT_Outline*  base    = &builder->base;
    FT_Outline*  outline = &builder->current;

    if (!builder->load_points)
    {
      outline->n_contours++;
      return T1_Err_Ok;
    }
    
    /* realloc contours array if necessary */
    if ( base->n_contours + outline->n_contours >= builder->max_contours &&
         builder->load_points )
    {
      T1_Error  error;
      FT_Memory memory = builder->memory;
      T1_Int    increment = outline->contours - base->contours;
      T1_Int    current   = builder->max_contours;

      builder->max_contours += 4;

      if ( REALLOC_ARRAY( base->contours,
                          current, builder->max_contours, T1_Short ) )
      {
        builder->error = error;
        return error;
      }
  
      outline->contours = base->contours + increment;
    }

    if (outline->n_contours > 0)
      outline->contours[ outline->n_contours-1 ] = outline->n_points-1;

    outline->n_contours++;
    return T1_Err_Ok;
  }

  /* if a path was begun, add its first on-curve point */
  static
  T1_Error  start_point( T1_Builder*  builder,
                         T1_Pos       x,
                         T1_Pos       y )
  {
    /* test wether we're building a new contour */
    if (!builder->path_begun)
    {
      T1_Error  error;
    
      builder->path_begun = 1;
      error = add_contour( builder );
      if (error) return error;
    }
    return add_point1( builder, x, y );
  }


  /* close the current contour */
  static
  void  close_contour( T1_Builder*  builder )
  {
    FT_Outline*  outline = &builder->current;

    if ( outline->n_contours > 0 )
      outline->contours[outline->n_contours-1] = outline->n_points-1;
  }


/*********************************************************************
 *
 * <Function>
 *    lookup_glyph_by_stdcharcode
 *
 * <Description>
 *    Lookup a given glyph by its StandardEncoding charcode. Used
 *    to implement the SEAC Type 1 operator.
 *
 * <Input>
 *    face     :: current face object         
 *    charcode :: charcode to look for
 *
 * <Return>
 *    glyph index in font face. Returns -1 if the corresponding
 *    glyph wasn't found.
 *
 *********************************************************************/

  static
  T1_Int    lookup_glyph_by_stdcharcode( T1_Face  face,
                                         T1_Int   charcode )
  {
    T1_Int              n;
    const T1_String*    glyph_name;
    PSNames_Interface*  psnames = (PSNames_Interface*)face->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 < face->type1.num_glyphs; n++ )
    {
      T1_String*  name = (T1_String*)face->type1.glyph_names[n];
      
      if ( name && 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  :: current Type 1 decoder
 *    asb      :: accent's side bearing
 *    adx      :: horizontal position of accent
 *    ady      :: vertical position of accent
 *    bchar    :: base character's StandardEncoding charcode
 *    achar    :: accent character's StandardEncoding charcode
 *
 * <Return>
 *    Error code. 0 means success.                               
 *
 *********************************************************************/

  static
  T1_Error  t1operator_seac( T1_Decoder*  decoder,
                             T1_Pos       asb,
                             T1_Pos       adx,
                             T1_Pos       ady,
                             T1_Int       bchar,