cffgload.c

source code: Covert TXT to PDF

/***************************************************************************/
/*                                                                         */
/*  cffgload.c                                                             */
/*                                                                         */
/*    OpenType Glyph Loader (body).                                        */
/*                                                                         */
/*  Copyright 1996-2001 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_CALC_H
#include FT_INTERNAL_STREAM_H
#include FT_INTERNAL_SFNT_H
#include FT_OUTLINE_H
#include FT_TRUETYPE_TAGS_H
#include FT_INTERNAL_POSTSCRIPT_HINTS_H

#include "cffobjs.h"
#include "cffload.h"
#include "cffgload.h"

#include "cfferrs.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_cffgload


  typedef enum  CFF_Operator_
  {
    cff_op_unknown = 0,

    cff_op_rmoveto,
    cff_op_hmoveto,
    cff_op_vmoveto,

    cff_op_rlineto,
    cff_op_hlineto,
    cff_op_vlineto,

    cff_op_rrcurveto,
    cff_op_hhcurveto,
    cff_op_hvcurveto,
    cff_op_rcurveline,
    cff_op_rlinecurve,
    cff_op_vhcurveto,
    cff_op_vvcurveto,

    cff_op_flex,
    cff_op_hflex,
    cff_op_hflex1,
    cff_op_flex1,

    cff_op_endchar,

    cff_op_hstem,
    cff_op_vstem,
    cff_op_hstemhm,
    cff_op_vstemhm,

    cff_op_hintmask,
    cff_op_cntrmask,
    cff_op_dotsection,  /* deprecated, acts as no-op */

    cff_op_abs,
    cff_op_add,
    cff_op_sub,
    cff_op_div,
    cff_op_neg,
    cff_op_random,
    cff_op_mul,
    cff_op_sqrt,

    cff_op_blend,

    cff_op_drop,
    cff_op_exch,
    cff_op_index,
    cff_op_roll,
    cff_op_dup,

    cff_op_put,
    cff_op_get,
    cff_op_store,
    cff_op_load,

    cff_op_and,
    cff_op_or,
    cff_op_not,
    cff_op_eq,
    cff_op_ifelse,

    cff_op_callsubr,
    cff_op_callgsubr,
    cff_op_return,

    /* do not remove */
    cff_op_max

  } CFF_Operator;


#define CFF_COUNT_CHECK_WIDTH  0x80
#define CFF_COUNT_EXACT        0x40
#define CFF_COUNT_CLEAR_STACK  0x20


  static const FT_Byte  cff_argument_counts[] =
  {
    0,  /* unknown */

    2 | CFF_COUNT_CHECK_WIDTH | CFF_COUNT_EXACT, /* rmoveto */
    1 | CFF_COUNT_CHECK_WIDTH | CFF_COUNT_EXACT,
    1 | CFF_COUNT_CHECK_WIDTH | CFF_COUNT_EXACT,

    0 | CFF_COUNT_CLEAR_STACK, /* rlineto */
    0 | CFF_COUNT_CLEAR_STACK,
    0 | CFF_COUNT_CLEAR_STACK,

    0 | CFF_COUNT_CLEAR_STACK, /* rrcurveto */
    0 | CFF_COUNT_CLEAR_STACK,
    0 | CFF_COUNT_CLEAR_STACK,
    0 | CFF_COUNT_CLEAR_STACK,
    0 | CFF_COUNT_CLEAR_STACK,
    0 | CFF_COUNT_CLEAR_STACK,
    0 | CFF_COUNT_CLEAR_STACK,

    13, /* flex */
    7,
    9,
    11,

    0 | CFF_COUNT_CHECK_WIDTH, /* endchar */

    2 | CFF_COUNT_CHECK_WIDTH, /* hstem */
    2 | CFF_COUNT_CHECK_WIDTH,
    2 | CFF_COUNT_CHECK_WIDTH,
    2 | CFF_COUNT_CHECK_WIDTH,

    0 | CFF_COUNT_CHECK_WIDTH, /* hintmask */
    0 | CFF_COUNT_CHECK_WIDTH, /* cntrmask */
    0, /* dotsection */

    1, /* abs */
    2,
    2,
    2,
    1,
    0,
    2,
    1,

    1, /* blend */

    1, /* drop */
    2,
    1,
    2,
    1,

    2, /* put */
    1,
    4,
    3,

    2, /* and */
    2,
    1,
    2,
    4,

    1, /* callsubr */
    1,
    0
  };


  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/
  /**********                                                      *********/
  /**********                                                      *********/
  /**********             GENERIC CHARSTRING PARSING               *********/
  /**********                                                      *********/
  /**********                                                      *********/
  /*************************************************************************/
  /*************************************************************************/
  /*************************************************************************/


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    CFF_Builder_Init                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Initializes a given glyph builder.                                 */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    builder :: A pointer to the glyph builder to initialize.           */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face    :: The current face object.                                */
  /*                                                                       */
  /*    size    :: The current size object.                                */
  /*                                                                       */
  /*    glyph   :: The current glyph object.                               */
  /*                                                                       */
  static void
  CFF_Builder_Init( CFF_Builder*   builder,
                    TT_Face        face,
                    CFF_Size       size,
                    CFF_GlyphSlot  glyph,
                    FT_Bool        hinting )
  {
    builder->path_begun  = 0;
    builder->load_points = 1;

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

    if ( glyph )
    {
      FT_GlyphLoader*  loader = glyph->root.internal->loader;


      builder->loader  = loader;
      builder->base    = &loader->base.outline;
      builder->current = &loader->current.outline;
      FT_GlyphLoader_Rewind( loader );

      builder->hints_globals = 0;
      builder->hints_funcs   = 0;
            
      if ( hinting && size )
      {
        builder->hints_globals = size->internal;
        builder->hints_funcs   = glyph->root.internal->glyph_hints;
      }
    }

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


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    CFF_Builder_Done                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Finalizes a given glyph builder.  Its contents can still be used   */
  /*    after the call, but the function saves important information       */
  /*    within the corresponding glyph slot.                               */
  /*                                                                       */
  /* <Input>                                                               */
  /*    builder :: A pointer to the glyph builder to finalize.             */
  /*                                                                       */
  static void
  CFF_Builder_Done( CFF_Builder*  builder )
  {
    CFF_GlyphSlot  glyph = builder->glyph;


    if ( glyph )
      glyph->root.outline = *builder->base;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    cff_compute_bias                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Computes the bias value in dependence of the number of glyph       */
  /*    subroutines.                                                       */
  /*                                                                       */
  /* <Input>                                                               */
  /*    num_subrs :: The number of glyph subroutines.                      */
  /*                                                                       */
  /* <Return>                                                              */
  /*    The bias value.                                                    */
  static FT_Int
  cff_compute_bias( FT_UInt  num_subrs )
  {
    FT_Int  result;


    if ( num_subrs < 1240 )
      result = 107;
    else if ( num_subrs < 33900U )
      result = 1131;
    else
      result = 32768U;

    return result;
  }


  /*************************************************************************/
  /*                                                                       */
  /* <Function>                                                            */
  /*    CFF_Init_Decoder                                                   */
  /*                                                                       */
  /* <Description>                                                         */
  /*    Initializes a given glyph decoder.                                 */
  /*                                                                       */
  /* <InOut>                                                               */
  /*    decoder :: A pointer to the glyph builder to initialize.           */
  /*                                                                       */
  /* <Input>                                                               */
  /*    face    :: The current face object.                                */
  /*                                                                       */
  /*    size    :: The current size object.                                */
  /*                                                                       */
  /*    slot    :: The current glyph object.                               */
  /*                                                                       */
  FT_LOCAL_DEF void
  CFF_Init_Decoder( CFF_Decoder*   decoder,
                    TT_Face        face,
                    CFF_Size       size,
                    CFF_GlyphSlot  slot,
                    FT_Bool        hinting )
  {
    CFF_Font*  cff = (CFF_Font*)face->extra.data;


    /* clear everything */
    MEM_Set( decoder, 0, sizeof ( *decoder ) );

    /* initialize builder */
    CFF_Builder_Init( &decoder->builder, face, size, slot, hinting );

    /* initialize Type2 decoder */
    decoder->num_globals  = cff->num_global_subrs;
    decoder->globals      = cff->global_subrs;
    decoder->globals_bias = cff_compute_bias( decoder->num_globals );
  }


  /* this function is used to select the locals subrs array */
  FT_LOCAL_DEF void
  CFF_Prepare_Decoder( CFF_Decoder*  decoder,
                       FT_UInt       glyph_index )
  {
    CFF_Font*     cff = (CFF_Font*)decoder->builder.face->extra.data;
    CFF_SubFont*  sub = &cff->top_font;


    /* manage CID fonts */
    if ( cff->num_subfonts >= 1 )
    {
      FT_Byte  fd_index = CFF_Get_FD( &cff->fd_select, glyph_index );


      sub = cff->subfonts[fd_index];
    }

    decoder->num_locals    = sub->num_local_subrs;
    decoder->locals        = sub->local_subrs;
    decoder->locals_bias   = cff_compute_bias( decoder->num_locals );

    decoder->glyph_width   = sub->private_dict.default_width;
    decoder->nominal_width = sub->private_dict.nominal_width;
  }


  /* check that there is enough room for `count' more points */
  static FT_Error
  check_points( CFF_Builder*  builder,
                FT_Int        count )
  {
    return FT_GlyphLoader_Check_Points( builder->loader, count, 0 );
  }


  /* add a new point, do not check space */
  static void
  add_point( CFF_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 >> 16;
      point->y = y >> 16;
      *control = (FT_Byte)( flag ? FT_Curve_Tag_On : FT_Curve_Tag_Cubic );

      builder->last = *point;
    }
    outline->n_points++;
  }


  /* check space for a new on-curve point, then add it */
  static FT_Error
  add_point1( CFF_Builder*  builder,
              FT_Pos        x,
              FT_Pos        y )
  {
    FT_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 FT_Error
  add_contour( CFF_Builder*  builder )
  {
    FT_Outline*  outline = builder->current;
    FT_Error     error;