groff before CVS: release 1.07

[s-roff.git] / troff / node.cc

// -*- C++ -*-
/* Copyright (C) 1989, 1990, 1991, 1992 Free Software Foundation, Inc.
     Written by James Clark (jjc@jclark.com)

This file is part of groff.

groff is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free
Software Foundation; either version 2, or (at your option) any later
version.

groff is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
for more details.

You should have received a copy of the GNU General Public License along
with groff; see the file COPYING.  If not, write to the Free Software
Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */

#include "troff.h"
#include "symbol.h"
#include "dictionary.h"
#include "hvunits.h"
#include "env.h"
#include "request.h"
#include "node.h"
#include "token.h"
#include "charinfo.h"
#include "font.h"
#include "reg.h"

#define STORE_WIDTH 1

symbol HYPHEN_SYMBOL("hy");

// Character used when a hyphen is inserted at a line break.
static charinfo *soft_hyphen_char;

enum constant_space_type { 
  CONSTANT_SPACE_NONE,
  CONSTANT_SPACE_RELATIVE,
  CONSTANT_SPACE_ABSOLUTE
  };

struct special_font_list {
  int n;
  special_font_list *next;
};

special_font_list *global_special_fonts;
static int global_ligature_mode = 1;
static int global_kern_mode = 1;

class track_kerning_function {
  int non_zero;
  units min_size;
  hunits min_amount;
  units max_size;
  hunits max_amount;
public:
  track_kerning_function();
  track_kerning_function(units, hunits, units, hunits);
  int operator==(const track_kerning_function &);
  int operator!=(const track_kerning_function &);
  hunits compute(int point_size);
};

// embolden fontno when this is the current font

struct conditional_bold {
  conditional_bold *next;
  int fontno;
  hunits offset;
  conditional_bold(int, hunits, conditional_bold * = 0);
};

struct tfont;

class font_info {
  tfont *last_tfont;
  int number;
  font_size last_size;
  int last_height;
  int last_slant;
  symbol internal_name;
  symbol external_name;
  font *fm;
  char is_bold;
  hunits bold_offset;
  track_kerning_function track_kern;
  constant_space_type is_constant_spaced;
  units constant_space;
  int last_ligature_mode;
  int last_kern_mode;
  conditional_bold *cond_bold_list;
  void flush();
public:
  special_font_list *sf;
  
  font_info(symbol nm, int n, symbol enm, font *f);
  int contains(charinfo *);
  void set_bold(hunits);
  void unbold();
  void set_conditional_bold(int, hunits);
  void conditional_unbold(int);
  void set_track_kern(track_kerning_function &);
  void set_constant_space(constant_space_type, units = 0);
  int is_named(symbol);
  symbol get_name();
  tfont *get_tfont(font_size, int, int, int);
  hunits get_space_width(font_size, int);
  hunits get_narrow_space_width(font_size);
  hunits get_half_narrow_space_width(font_size);
  int get_bold(hunits *);
  int is_special();
  int is_style();
};

class tfont_spec {
protected:
  symbol name;
  int input_position;
  font *fm;
  font_size size;
  char is_bold;
  char is_constant_spaced;
  int ligature_mode;
  int kern_mode;
  hunits bold_offset;
  hunits track_kern;                    // add this to the width
  hunits constant_space_width;
  int height;
  int slant;
public:
  tfont_spec(symbol nm, int pos, font *, font_size, int, int);
  tfont_spec plain();
  int operator==(const tfont_spec &);
  friend tfont *font_info::get_tfont(font_size fs, int, int, int);
};

class tfont : public tfont_spec {
  static tfont *tfont_list;
  tfont *next;
  tfont *plain_version;
public:
  tfont(tfont_spec &);
  int contains(charinfo *);
  hunits get_width(charinfo *c);
  int get_bold(hunits *);
  int get_constant_space(hunits *);
  hunits get_track_kern();
  tfont *get_plain();
  font_size get_size();
  symbol get_name();
  charinfo *get_lig(charinfo *c1, charinfo *c2);
  int get_kern(charinfo *c1, charinfo *c2, hunits *res);
  int get_input_position();
  int get_character_type(charinfo *);
  int get_height();
  int get_slant();
  vunits get_char_height(charinfo *);
  vunits get_char_depth(charinfo *);
  hunits get_char_skew(charinfo *);
  hunits get_italic_correction(charinfo *);
  hunits get_left_italic_correction(charinfo *);
  hunits get_subscript_correction(charinfo *);
  friend tfont *make_tfont(tfont_spec &);
};

inline int env_definite_font(environment *env)
{
  return env->get_family()->make_definite(env->get_font());
}

static void invalidate_fontno(int n);

/* font_info functions */

static font_info **font_table = 0;
static int font_table_size = 0;

font_info::font_info(symbol nm, int n, symbol enm, font *f)
: internal_name(nm), external_name(enm), fm(f), number(n),
  is_constant_spaced(CONSTANT_SPACE_NONE),
  sf(0), is_bold(0), cond_bold_list(0),
  last_ligature_mode(1), last_kern_mode(1),
  last_tfont(0), last_size(0)
{
}

inline int font_info::contains(charinfo *ci)
{
  return fm != 0 && fm->contains(ci->get_index());
}

inline int font_info::is_special()
{
  return fm != 0 && fm->is_special();
}

inline int font_info::is_style()
{
  return fm == 0;
}

// this is the current_font, fontno is where we found the character,
// presumably a special font

tfont *font_info::get_tfont(font_size fs, int height, int slant, int fontno)
{
  if (last_tfont == 0 || fs != last_size
      || height != last_height || slant != last_slant
      || global_ligature_mode != last_ligature_mode
      || global_kern_mode != last_kern_mode
      || fontno != number) {
        font_info *f = font_table[fontno];
        tfont_spec spec(f->external_name, f->number, f->fm, fs, height, slant);
        for (conditional_bold *p = cond_bold_list; p; p = p->next)
          if (p->fontno == fontno) {
            spec.is_bold = 1;
            spec.bold_offset = p->offset;
            break;
          }
        if (!spec.is_bold && is_bold) {
          spec.is_bold = 1;
          spec.bold_offset = bold_offset;
        }
        spec.track_kern = track_kern.compute(fs.to_scaled_points());
        spec.ligature_mode = global_ligature_mode;
        spec.kern_mode = global_kern_mode;
        switch (is_constant_spaced) {
        case CONSTANT_SPACE_NONE:
          break;
        case CONSTANT_SPACE_ABSOLUTE:
          spec.is_constant_spaced = 1;
          spec.constant_space_width = constant_space;
          break;
        case CONSTANT_SPACE_RELATIVE:
          spec.is_constant_spaced = 1;
          spec.constant_space_width
            = scale(constant_space*fs.to_scaled_points(),
                    units_per_inch,
                    36*72*sizescale);
          break;
        default:
          assert(0);
        }
        if (fontno != number)
          return make_tfont(spec);
        last_tfont = make_tfont(spec);
        last_size = fs;
        last_height = height;
        last_slant = slant;
        last_ligature_mode = global_ligature_mode;
        last_kern_mode = global_kern_mode;
      }
  return last_tfont;
}

int font_info::get_bold(hunits *res)
{
  if (is_bold) {
    *res = bold_offset;
    return 1;
  }
  else
    return 0;
}

void font_info::unbold()
{
  if (is_bold) {
    is_bold = 0;
    flush();
  }
}

void font_info::set_bold(hunits offset)
{
  if (!is_bold || offset != bold_offset) {
    is_bold = 1;
    bold_offset = offset;
    flush();
  }
}

void font_info::set_conditional_bold(int fontno, hunits offset)
{
  for (conditional_bold *p = cond_bold_list; p; p = p->next)
    if (p->fontno == fontno) {
      if (offset != p->offset) {
        p->offset = offset;
        flush();
      }
      return;
    }
  cond_bold_list = new conditional_bold(fontno, offset, cond_bold_list);
}

conditional_bold::conditional_bold(int f, hunits h, conditional_bold *x)
     : fontno(f), offset(h), next(x)
{
}

void font_info::conditional_unbold(int fontno)
{
  for (conditional_bold **p = &cond_bold_list; *p; p = &(*p)->next)
    if ((*p)->fontno == fontno) {
      conditional_bold *tem = *p;
      *p = (*p)->next;
      delete tem;
      flush();
      return;
    }
}
                                 
void font_info::set_constant_space(constant_space_type type, units x)
{
  if (type != is_constant_spaced
      || (type != CONSTANT_SPACE_NONE && x != constant_space)) {
        flush();
        is_constant_spaced = type;
        constant_space = x;
      }
}

void font_info::set_track_kern(track_kerning_function  &tk)
{
  if (track_kern != tk) {
    track_kern = tk;
    flush();
  }
}

void font_info::flush()
{
  last_tfont = 0;
}

int font_info::is_named(symbol s)
{
  return internal_name == s;
}

symbol font_info::get_name()
{
  return internal_name;
}

hunits font_info::get_space_width(font_size fs, int space_size)
{
  if (is_constant_spaced == CONSTANT_SPACE_NONE)
    return scale(hunits(fm->get_space_width(fs.to_scaled_points())),
                        space_size, 12);
  else if (is_constant_spaced == CONSTANT_SPACE_ABSOLUTE)
    return constant_space;
  else
    return scale(constant_space*fs.to_scaled_points(),
                 units_per_inch, 36*72*sizescale);
}

hunits font_info::get_narrow_space_width(font_size fs)
{
  charinfo *ci = get_charinfo(symbol("|"));
  if (fm->contains(ci->get_index()))
    return hunits(fm->get_width(ci->get_index(), fs.to_scaled_points()));
  else
    return hunits(fs.to_units()/6);
}

hunits font_info::get_half_narrow_space_width(font_size fs)
{
  charinfo *ci = get_charinfo(symbol("^"));
  if (fm->contains(ci->get_index()))
    return hunits(fm->get_width(ci->get_index(), fs.to_scaled_points()));
  else
    return hunits(fs.to_units()/12);
}

/* tfont */

tfont_spec::tfont_spec(symbol nm, int n, font *f, 
                       font_size s, int h, int sl)
     : name(nm), input_position(n), fm(f), size(s),
     is_bold(0), is_constant_spaced(0), ligature_mode(1), kern_mode(1),
     height(h), slant(sl)
{
  if (height == size.to_scaled_points())
    height = 0;
}

int tfont_spec::operator==(const tfont_spec &spec)
{
  if (fm == spec.fm 
      && size == spec.size
      && input_position == spec.input_position
      && name == spec.name
      && height == spec.height
      && slant == spec.slant
      && (is_bold 
          ? (spec.is_bold && bold_offset == spec.bold_offset)
          : !spec.is_bold)
      && track_kern == spec.track_kern
      && (is_constant_spaced
          ? (spec.is_constant_spaced 
             && constant_space_width == spec.constant_space_width)
          : !spec.is_constant_spaced)
      && ligature_mode == spec.ligature_mode
      && kern_mode == spec.kern_mode)
    return 1;
  else
    return 0;
}

tfont_spec tfont_spec::plain()
{
  return tfont_spec(name, input_position, fm, size, height, slant);
}

hunits tfont::get_width(charinfo *c)
{
  if (is_constant_spaced)
    return constant_space_width;
  else if (is_bold)
    return (hunits(fm->get_width(c->get_index(), size.to_scaled_points()))
            + track_kern + bold_offset);
  else
    return (hunits(fm->get_width(c->get_index(), size.to_scaled_points())) + track_kern);
}

vunits tfont::get_char_height(charinfo *c)
{
  vunits v = fm->get_height(c->get_index(), size.to_scaled_points());
  if (height != 0 && height != size.to_scaled_points())
    return scale(v, height, size.to_scaled_points());
  else
    return v;
}

vunits tfont::get_char_depth(charinfo *c)
{
  vunits v = fm->get_depth(c->get_index(), size.to_scaled_points());
  if (height != 0 && height != size.to_scaled_points())
    return scale(v, height, size.to_scaled_points());
  else
    return v;
}

hunits tfont::get_char_skew(charinfo *c)
{
  return hunits(fm->get_skew(c->get_index(), size.to_scaled_points(), slant));
}

hunits tfont::get_italic_correction(charinfo *c)
{
  return hunits(fm->get_italic_correction(c->get_index(), size.to_scaled_points()));
}

hunits tfont::get_left_italic_correction(charinfo *c)
{
  return hunits(fm->get_left_italic_correction(c->get_index(),
                                               size.to_scaled_points()));
}

hunits tfont::get_subscript_correction(charinfo *c)
{
  return hunits(fm->get_subscript_correction(c->get_index(),
                                             size.to_scaled_points()));
}

inline int tfont::get_input_position()
{
  return input_position;
}

inline int tfont::contains(charinfo *ci)
{
  return fm->contains(ci->get_index());
}

inline int tfont::get_character_type(charinfo *ci)
{
  return fm->get_character_type(ci->get_index());
}

inline int tfont::get_bold(hunits *res)
{
  if (is_bold) {
    *res = bold_offset;
    return 1;
  }
  else
    return 0;
}

inline int tfont::get_constant_space(hunits *res)
{
  if (is_constant_spaced) {
    *res = constant_space_width;
    return 1;
  }
  else
    return 0;
}

inline hunits tfont::get_track_kern()
{
  return track_kern;
}

inline tfont *tfont::get_plain()
{
  return plain_version;
}

inline font_size tfont::get_size()
{
  return size;
}

inline symbol tfont::get_name()
{
  return name;
}

inline int tfont::get_height()
{
  return height;
}

inline int tfont::get_slant()
{
  return slant;
}

symbol SYMBOL_ff("ff");
symbol SYMBOL_fi("fi");
symbol SYMBOL_fl("fl");
symbol SYMBOL_Fi("Fi");
symbol SYMBOL_Fl("Fl");

charinfo *tfont::get_lig(charinfo *c1, charinfo *c2)
{
  if (ligature_mode == 0)
    return 0;
  charinfo *ci = 0;
  if (c1->get_ascii_code() == 'f') {
    switch (c2->get_ascii_code()) {
    case 'f':
      if (fm->has_ligature(font::LIG_ff))
        ci = get_charinfo(SYMBOL_ff);
      break;
    case 'i':
      if (fm->has_ligature(font::LIG_fi))
        ci = get_charinfo(SYMBOL_fi);
      break;
    case 'l':
      if (fm->has_ligature(font::LIG_fl))
        ci = get_charinfo(SYMBOL_fl);
      break;
    }
  }
  else if (ligature_mode != 2 && c1->nm == SYMBOL_ff) {
    switch (c2->get_ascii_code()) {
    case 'i':
      if (fm->has_ligature(font::LIG_ffi))
        ci = get_charinfo(SYMBOL_Fi);
      break;
    case 'l':
      if (fm->has_ligature(font::LIG_ffl))
        ci = get_charinfo(SYMBOL_Fl);
      break;
    }
  }
  if (ci != 0 && fm->contains(ci->get_index()))
    return ci;
  return 0;
}

inline int tfont::get_kern(charinfo *c1, charinfo *c2, hunits *res)
{
  if (kern_mode == 0)
    return 0;
  else {
    int n = fm->get_kern(c1->get_index(),
                         c2->get_index(),
                         size.to_scaled_points());
    if (n) {
      *res = hunits(n);
      return 1;
    }
    else
      return 0;
  }
}

tfont *make_tfont(tfont_spec &spec)
{
  for (tfont *p = tfont::tfont_list; p; p = p->next)
    if (*p == spec)
      return p;
  return new tfont(spec);
}

tfont *tfont::tfont_list = 0;

tfont::tfont(tfont_spec &spec) : tfont_spec(spec)
{
  next = tfont_list;
  tfont_list = this;
  tfont_spec plain_spec = plain();
  for (tfont *p = tfont_list; p; p = p->next)
    if (*p == plain_spec) {
      plain_version = p;
      break;
    }
  if (!p)
    plain_version = new tfont(plain_spec);
}

/* output_file */

class real_output_file : public output_file {
  int piped;
  int printing;
  virtual void really_transparent_char(unsigned char) = 0;
  virtual void really_print_line(hunits x, vunits y, node *n,
                                 vunits before, vunits after) = 0;
  virtual void really_begin_page(int pageno, vunits page_length) = 0;
  virtual void really_copy_file(hunits x, vunits y, const char *filename);
protected:
  FILE *fp;
public:
  real_output_file();
  ~real_output_file();
  void flush();
  void transparent_char(unsigned char);
  void print_line(hunits x, vunits y, node *n, vunits before, vunits after);
  void begin_page(int pageno, vunits page_length);
  int is_printing();
  void copy_file(hunits x, vunits y, const char *filename);
};

class suppress_output_file : public real_output_file {
public:
  suppress_output_file();
  void really_transparent_char(unsigned char);
  void really_print_line(hunits x, vunits y, node *n, vunits, vunits);
  void really_begin_page(int pageno, vunits page_length);
};

class ascii_output_file : public real_output_file {
public:
  ascii_output_file();
  void really_transparent_char(unsigned char);
  void really_print_line(hunits x, vunits y, node *n, vunits, vunits);
  void really_begin_page(int pageno, vunits page_length);
  void outc(unsigned char c);
  void outs(const char *s);
};

void ascii_output_file::outc(unsigned char c)
{
  fputc(c, fp);
}

void ascii_output_file::outs(const char *s)
{
  fputc('<', fp);
  if (s)
    fputs(s, fp);
  fputc('>', fp);
}

struct hvpair;
      
class troff_output_file : public real_output_file {
  units hpos;
  units vpos;
  units output_vpos;
  units output_hpos;
  int force_motion;
  int current_size;
  int current_slant;
  int current_height;
  tfont *current_tfont;
  int current_font_number;
  symbol *font_position;
  int nfont_positions;
  enum { TBUF_SIZE = 256 };
  char tbuf[TBUF_SIZE];
  int tbuf_len;
  int tbuf_kern;
  void do_motion();
  vunits page_length;
  void put(char c);
  void put(unsigned char c);
  void put(int i);
  void put(const char *s);
  void set_font(tfont *tf);
  void flush_tbuf();
public:
  troff_output_file();
  ~troff_output_file();
  void put_char(charinfo *ci, tfont *tf);
  void put_char_width(charinfo *ci, tfont *tf, hunits w, hunits k);
  void right(hunits);
  void down(vunits);
  void moveto(hunits, vunits);
  void start_special();
  void special_char(unsigned char c);
  void end_special();
  void word_marker();
  void really_transparent_char(unsigned char c);
  void really_print_line(hunits x, vunits y, node *n, vunits before, vunits after);
  void really_begin_page(int pageno, vunits page_length);
  void really_copy_file(hunits x, vunits y, const char *filename);
  void draw(char, hvpair *, int, font_size);
  int get_hpos() { return hpos; }
  int get_vpos() { return vpos; }
};

static void put_string(const char *s, FILE *fp)
{
  for (; *s != '\0'; ++s)
    putc(*s, fp);
}

inline void troff_output_file::put(char c)
{
  putc(c, fp);
}

inline void troff_output_file::put(unsigned char c)
{
  putc(c, fp);
}

inline void troff_output_file::put(const char *s)
{
  put_string(s, fp);
}

inline void troff_output_file::put(int i)
{
  put_string(itoa(i), fp);
}

void troff_output_file::start_special()
{
  flush_tbuf();
  do_motion();
  put("x X ");
}

void troff_output_file::special_char(unsigned char c)
{
  put(c);
  if (c == '\n')
    put('+');
}

void troff_output_file::end_special()
{
  put('\n');
}

inline void troff_output_file::moveto(hunits h, vunits v)
{
  hpos = h.to_units();
  vpos = v.to_units();
}

void troff_output_file::really_print_line(hunits x, vunits y, node *n,
                                          vunits before, vunits after)
{
  moveto(x, y);
  while (n != 0) {
    n->tprint(this);
    n = n->next;
  }
  flush_tbuf();
  // This ensures that transparent throughput will have a more predictable
  // position.
  do_motion();
  force_motion = 1;
  hpos = 0;
  put('n');
  put(before.to_units());
  put(' ');
  put(after.to_units());
  put('\n');
}

inline void troff_output_file::word_marker()
{
  flush_tbuf();
  put('w');
}

inline void troff_output_file::right(hunits n)
{
  hpos += n.to_units();
}

inline void troff_output_file::down(vunits n)
{
  vpos += n.to_units();
}

void troff_output_file::do_motion()
{
  if (force_motion) {
    put('V');
    put(vpos);
    put('\n');
    put('H');
    put(hpos);
    put('\n');
  }
  else {
    if (hpos != output_hpos) {
      units n = hpos - output_hpos;
      if (n > 0 && n < hpos) {
        put('h');
        put(n);
      }
      else {
        put('H');
        put(hpos);
      }
      put('\n');
    }
    if (vpos != output_vpos) {
      units n = vpos - output_vpos;
      if (n > 0 && n < vpos) {
        put('v');
        put(n);
      }
      else {
        put('V');
        put(vpos);
      }
      put('\n');
    }
  }
  output_vpos = vpos;
  output_hpos = hpos;
  force_motion = 0;
}

void troff_output_file::flush_tbuf()
{
  if (tbuf_len == 0)
    return;
  if (tbuf_kern == 0)
    put('t');
  else {
    put('u');
    put(tbuf_kern);
    put(' ');
  }
  for (int i = 0; i < tbuf_len; i++)
    put(tbuf[i]);
  put('\n');
  tbuf_len = 0;
}

void troff_output_file::put_char_width(charinfo *ci, tfont *tf, hunits w,
                                       hunits k)
{
  if (tf != current_tfont) {
    flush_tbuf();
    set_font(tf);
  }
  char c = ci->get_ascii_code();
  int kk = k.to_units();
  if (c == '\0') {
    flush_tbuf();
    do_motion();
    if (ci->numbered()) {
      put('N');
      put(ci->get_number());
    }
    else {
      put('C');
      const char *s = ci->nm.contents();
      if (s[1] == 0) {
        put('\\');
        put(s[0]);
      }
      else
        put(s);
    }
    put('\n');
    hpos += w.to_units() + kk;
  }
  else if (tcommand_flag) {
    if (tbuf_len > 0 && hpos == output_hpos && vpos == output_vpos
        && kk == tbuf_kern
        && tbuf_len < TBUF_SIZE) {
      tbuf[tbuf_len++] = c;
      output_hpos += w.to_units() + kk;
      hpos = output_hpos;
      return;
    }
    flush_tbuf();
    do_motion();
    tbuf[tbuf_len++] = c;
    output_hpos += w.to_units() + kk;
    tbuf_kern = kk;
    hpos = output_hpos;
  }
  else {
    // flush_tbuf();
    int n = hpos - output_hpos;
    if (vpos == output_vpos && n > 0 && n < 100 && !force_motion) {
      put(char(n/10 + '0'));
      put(char(n%10 + '0'));
      put(c);
      output_hpos = hpos;
    }
    else {
      do_motion();
      put('c');
      put(c);
    }
    hpos += w.to_units() + kk;
  }
}

void troff_output_file::put_char(charinfo *ci, tfont *tf)
{
  flush_tbuf();
  if (tf != current_tfont)
    set_font(tf);
  char c = ci->get_ascii_code();
  if (c == '\0') {
    do_motion();
    if (ci->numbered()) {
      put('N');
      put(ci->get_number());
    }
    else {
      put('C');
      const char *s = ci->nm.contents();
      if (s[1] == 0) {
        put('\\');
        put(s[0]);
      }
      else
        put(s);
    }
    put('\n');
  }
  else {
    int n = hpos - output_hpos;
    if (vpos == output_vpos && n > 0 && n < 100) {
      put(char(n/10 + '0'));
      put(char(n%10 + '0'));
      put(c);
      output_hpos = hpos;
    }
    else {
      do_motion();
      put('c');
      put(c);
    }
  }
}

void troff_output_file::set_font(tfont *tf)
{
  if (current_tfont == tf)
    return;
  int n = tf->get_input_position();
  symbol nm = tf->get_name();
  if (n >= nfont_positions || font_position[n] != nm) {
    put("x font ");
    put(n);
    put(' ');
    put(nm.contents());
    put('\n');
    if (n >= nfont_positions) {
      int old_nfont_positions = nfont_positions;
      symbol *old_font_position = font_position;
      nfont_positions *= 3;
      nfont_positions /= 2;
      if (nfont_positions <= n)
        nfont_positions = n + 10;
      font_position = new symbol[nfont_positions];
      memcpy(font_position, old_font_position,
             old_nfont_positions*sizeof(symbol));
      a_delete old_font_position;
    }
    font_position[n] = nm;
  }
  if (current_font_number != n) {
    put('f');
    put(n);
    put('\n');
    current_font_number = n;
  }
  int size = tf->get_size().to_scaled_points();
  if (current_size != size) {
    put('s');
    put(size);
    put('\n');
    current_size = size;
  }
  int slant = tf->get_slant();
  if (current_slant != slant) {
    put("x Slant ");
    put(slant);
    put('\n');
    current_slant = slant;
  }
  int height = tf->get_height();
  if (current_height != height) {
    put("x Height ");
    put(height == 0 ? current_size : height);
    put('\n');
    current_height = height;
  }
  current_tfont = tf;
}

void troff_output_file::draw(char code, hvpair *point, int npoints,
                             font_size fsize)
{
  flush_tbuf();
  do_motion();
  int size = fsize.to_scaled_points();
  if (current_size != size) {
    put('s');
    put(size);
    put('\n');
    current_size = size;
    current_tfont = 0;
  }
  put('D');
  put(code);
  int i;
  if (code == 'c') {
    put(' ');
    put(point[0].h.to_units());
  }
  else
    for (i = 0; i < npoints; i++) {
      put(' ');
      put(point[i].h.to_units());
      put(' ');
      put(point[i].v.to_units());
    }
  for (i = 0; i < npoints; i++)
    output_hpos += point[i].h.to_units();
  hpos = output_hpos;
  if (code != 'e') {
    for (i = 0; i < npoints; i++)
      output_vpos += point[i].v.to_units();
    vpos = output_vpos;
  }
  put('\n');
}

void troff_output_file::really_begin_page(int pageno, vunits pl)
{
  flush_tbuf();
  if (page_length > V0) {
    put('V');
    put(page_length.to_units());
    put('\n');
  }
  page_length = pl;
  current_tfont = 0;
  current_font_number = -1;
  current_size = 0;
  // current_height = 0;
  // current_slant = 0;
  hpos = 0;
  vpos = 0;
  output_hpos = 0;
  output_vpos = 0;
  force_motion = 1;
  for (int i = 0; i < nfont_positions; i++)
    font_position[i] = NULL_SYMBOL;
  put('p');
  put(pageno);
  put('\n');
}

void troff_output_file::really_copy_file(hunits x, vunits y, const char *filename)
{
  moveto(x, y);
  flush_tbuf();
  do_motion();
  errno = 0;
  FILE *ifp = fopen(filename, "r");
  if (ifp == 0)
    error("can't open `%1': %2", filename, strerror(errno));
  else {
    int c;
    while ((c = getc(ifp)) != EOF)
      put(char(c));
    fclose(ifp);
  }
  force_motion = 1;
  current_size = 0;
  current_tfont = 0;
  current_font_number = -1;
  for (int i = 0; i < nfont_positions; i++)
    font_position[i] = NULL_SYMBOL;
}
  
void troff_output_file::really_transparent_char(unsigned char c)
{
  put(c);
}

troff_output_file::~troff_output_file()
{
  flush_tbuf();
  if (page_length > V0) {
    put("x trailer\n");
    put('V');
    put(page_length.to_units());
    put('\n');
  }
  put("x stop\n");
  a_delete font_position;
}

troff_output_file::troff_output_file()
: current_height(0), current_slant(0), tbuf_len(0), nfont_positions(10)
{
  font_position = new symbol[nfont_positions];
  put("x T ");
  put(device);
  put('\n');
  put("x res ");
  put(units_per_inch);
  put(' ');
  put(hresolution);
  put(' ');
  put(vresolution);
  put('\n');
  put("x init\n");
}

/* output_file */

output_file *the_output = 0;

output_file::output_file()
{
}

output_file::~output_file()
{
}

real_output_file::real_output_file()
: printing(0)
{
  if (pipe_command) {
    if ((fp = popen(pipe_command, "w")) != 0) {
      piped = 1;
      return;
    }
    error("pipe open failed: %1", strerror(errno));
  }
  piped = 0;
  fp = stdout;
}

real_output_file::~real_output_file()
{
  if (!fp)
    return;
  // To avoid looping, set fp to 0 before calling fatal().
  if (ferror(fp) || fflush(fp) < 0) {
    fp = 0;
    fatal("error writing output file");
  }
  if (piped) {
    int result = pclose(fp);
    fp = 0;
    if (result < 0)
      fatal("pclose failed");
    if ((result & 0x7f) != 0)
      error("output process `%1' got fatal signal %2",
            pipe_command, result & 0x7f);
    else {
      int exit_status = (result >> 8) & 0xff;
      if (exit_status != 0)
        error("output process `%1' exited with status %2",
              pipe_command, exit_status);
    }
  }
  else if (fclose(fp) < 0) {
    fp = 0;
    fatal("error closing output file");
  }
}

void real_output_file::flush()
{
  if (fflush(fp) < 0)
    fatal("error writing output file");
}

int real_output_file::is_printing()
{
  return printing;
}

void real_output_file::begin_page(int pageno, vunits page_length)
{
  printing = in_output_page_list(pageno);
  if (printing)
    really_begin_page(pageno, page_length);
}

void real_output_file::copy_file(hunits x, vunits y, const char *filename)
{
  if (printing)
    really_copy_file(x, y, filename);
}

void real_output_file::transparent_char(unsigned char c)
{
  if (printing)
    really_transparent_char(c);
}

void real_output_file::print_line(hunits x, vunits y, node *n,
                             vunits before, vunits after)
{
  if (printing)
    really_print_line(x, y, n, before, after);
  delete_node_list(n);
}

void real_output_file::really_copy_file(hunits, vunits, const char *)
{
  // do nothing
}


/* ascii_output_file */

void ascii_output_file::really_transparent_char(unsigned char c)
{
  putc(c, fp);
}

void ascii_output_file::really_print_line(hunits, vunits, node *n, vunits, vunits)
{
  while (n != 0) {
    n->ascii_print(this);
    n = n->next;
  }
  fputc('\n', fp);
}

void ascii_output_file::really_begin_page(int /*pageno*/, vunits /*page_length*/)
{
  fputs("<beginning of page>\n", fp);
}

ascii_output_file::ascii_output_file()
{
}

/* suppress_output_file */

suppress_output_file::suppress_output_file()
{
}

void suppress_output_file::really_print_line(hunits, vunits, node *, vunits, vunits)
{
}

void suppress_output_file::really_begin_page(int, vunits)
{
}

void suppress_output_file::really_transparent_char(unsigned char)
{
}

/* glyphs, ligatures, kerns, discretionary breaks */

class glyph_node : public node {
  static glyph_node *free_list;
protected:
  charinfo *ci;
  tfont *tf;
#ifdef STORE_WIDTH
  hunits wid;
  glyph_node(charinfo *, tfont *, hunits, node * = 0);
#endif
public:
  void *operator new(size_t);
  void operator delete(void *);
  glyph_node(charinfo *, tfont *, node * = 0);
  ~glyph_node() {}
  node *copy();
  node *merge_glyph_node(glyph_node *);
  node *merge_self(node *);
  hunits width();
  node *last_char_node();
  units size();
  void vertical_extent(vunits *, vunits *);
  hunits subscript_correction();
  hunits italic_correction();
  hunits left_italic_correction();
  hunits skew();
  hyphenation_type get_hyphenation_type();
  tfont *get_tfont();
  void tprint(troff_output_file *);
  void zero_width_tprint(troff_output_file *);
  hyphen_list *get_hyphen_list(hyphen_list *ss = 0);
  node *add_self(node *, hyphen_list **);
  int ends_sentence();
  int overlaps_vertically();
  int overlaps_horizontally();
  void ascii_print(ascii_output_file *);
  void asciify(macro *);
  int character_type();
  int same(node *);
  const char *type();
};

glyph_node *glyph_node::free_list = 0;

class ligature_node : public glyph_node {
  node *n1;
  node *n2;
#ifdef STORE_WIDTH
  ligature_node(charinfo *, tfont *, hunits, node *gn1, node *gn2, node *x = 0);
#endif
public:
  void *operator new(size_t);
  void operator delete(void *);
  ligature_node(charinfo *, tfont *, node *gn1, node *gn2, node *x = 0);
  ~ligature_node();
  node *copy();
  node *add_self(node *, hyphen_list **);
  hyphen_list *get_hyphen_list(hyphen_list *ss = 0);
  void ascii_print(ascii_output_file *);
  void asciify(macro *);
  int same(node *);
  const char *type();
};

class kern_pair_node : public node {
  hunits amount;
  node *n1;
  node *n2;
public:
  kern_pair_node(hunits n, node *first, node *second, node *x = 0);
  ~kern_pair_node();
  node *copy();
  node *merge_glyph_node(glyph_node *);
  node *add_self(node *, hyphen_list **);
  hyphen_list *get_hyphen_list(hyphen_list *ss = 0);
  node *add_discretionary_hyphen();
  hunits width();
  node *last_char_node();
  hunits italic_correction();
  hunits subscript_correction();
  void tprint(troff_output_file *);
  hyphenation_type get_hyphenation_type();
  int ends_sentence();
  void ascii_print(ascii_output_file *);
  void asciify(macro *);
  int same(node *);
  const char *type();
};

class dbreak_node : public node {
  node *none;
  node *pre;
  node *post;
public:
  dbreak_node(node *n, node *p, node *x = 0);
  ~dbreak_node();
  node *copy();
  node *merge_glyph_node(glyph_node *);
  node *add_discretionary_hyphen();
  hunits width();
  node *last_char_node();
  hunits italic_correction();
  hunits subscript_correction();
  void tprint(troff_output_file *);
  breakpoint *get_breakpoints(hunits width, int ns, breakpoint *rest = 0,
                              int is_inner = 0);
  int nbreaks();
  int ends_sentence();
  void split(int, node **, node **);
  hyphenation_type get_hyphenation_type();
  void ascii_print(ascii_output_file *);
  void asciify(macro *);
  int same(node *);
  const char *type();
};

void *glyph_node::operator new(size_t n)
{
  assert(n == sizeof(glyph_node));
  if (!free_list) {
    const int BLOCK = 1024;
    free_list = (glyph_node *)new char[sizeof(glyph_node)*BLOCK];
    for (int i = 0; i < BLOCK - 1; i++)
      free_list[i].next = free_list + i + 1;
    free_list[BLOCK-1].next = 0;
  }
  glyph_node *p = free_list;
  free_list = (glyph_node *)(free_list->next);
  p->next = 0;
  return p;
}

void *ligature_node::operator new(size_t n)
{
  return new char[n];
}

void glyph_node::operator delete(void *p)
{
  if (p) {
    ((glyph_node *)p)->next = free_list;
    free_list = (glyph_node *)p;
  }
}

void ligature_node::operator delete(void *p)
{
  delete p;
}

glyph_node::glyph_node(charinfo *c, tfont *t, node *x)
     : ci(c), tf(t), node(x)
{
#ifdef STORE_WIDTH
  wid = tf->get_width(ci);
#endif
}

#ifdef STORE_WIDTH
glyph_node::glyph_node(charinfo *c, tfont *t, hunits w, node *x)
     : ci(c), tf(t), wid(w), node(x)
{
}
#endif

node *glyph_node::copy()
{
#ifdef STORE_WIDTH
  return new glyph_node(ci, tf, wid);
#else
  return new glyph_node(ci, tf);
#endif
}

node *glyph_node::merge_self(node *nd)
{
  return nd->merge_glyph_node(this);
}

int glyph_node::character_type()
{
  return tf->get_character_type(ci);
}

node *glyph_node::add_self(node *n, hyphen_list **p)
{
  assert(ci->get_hyphenation_code() == (*p)->hyphenation_code);
  next = 0;
  node *nn;
  if (n == 0 || (nn = n->merge_glyph_node(this)) == 0) {
    next = n;
    nn = this;
  }
  if ((*p)->hyphen)
    nn = nn->add_discretionary_hyphen();
  hyphen_list *pp = *p;
  *p = (*p)->next;
  delete pp;
  return nn;
}

int glyph_node::overlaps_horizontally()
{
  return ci->overlaps_horizontally();
}

int glyph_node::overlaps_vertically()
{
  return ci->overlaps_vertically();
}

units glyph_node::size()
{
  return tf->get_size().to_units();
}

hyphen_list *glyph_node::get_hyphen_list(hyphen_list *tail)
{
  return new hyphen_list(ci->get_hyphenation_code(), tail);
}


tfont *node::get_tfont()
{
  return 0;
}

tfont *glyph_node::get_tfont()
{
  return tf;
}

node *node::merge_glyph_node(glyph_node * /*gn*/)
{
  return 0;
}

node *glyph_node::merge_glyph_node(glyph_node *gn)
{
  if (tf == gn->tf) {
    charinfo *lig;
    if ((lig = tf->get_lig(ci, gn->ci)) != 0) {
      node *next1 = next;
      next = 0;
      return new ligature_node(lig, tf, this, gn, next1);
    }
    hunits kern;
    if (tf->get_kern(ci, gn->ci, &kern)) {
      node *next1 = next;
      next = 0;
      return new kern_pair_node(kern, this, gn, next1);
    }
  }
  return 0;
}

#ifdef STORE_WIDTH
inline
#endif
hunits glyph_node::width()
{
#ifdef STORE_WIDTH
  return wid;
#else
  return tf->get_width(ci);
#endif
}

node *glyph_node::last_char_node()
{
  return this;
}

void glyph_node::vertical_extent(vunits *min, vunits *max)
{
  *min = -tf->get_char_height(ci);
  *max = tf->get_char_depth(ci);
}

hunits glyph_node::skew()
{
  return tf->get_char_skew(ci);
}

hunits glyph_node::subscript_correction()
{
  return tf->get_subscript_correction(ci);
}

hunits glyph_node::italic_correction()
{
  return tf->get_italic_correction(ci);
}

hunits glyph_node::left_italic_correction()
{
  return tf->get_left_italic_correction(ci);
}

hyphenation_type glyph_node::get_hyphenation_type()
{
  return HYPHEN_MIDDLE;
}

int glyph_node::ends_sentence()
{
  if (ci->ends_sentence())
    return 1;
  else if (ci->transparent())
    return 2;
  else
    return 0;
}

void glyph_node::ascii_print(ascii_output_file *ascii)
{
  unsigned char c = ci->get_ascii_code();
  if (c != 0)
    ascii->outc(c);
  else
    ascii->outs(ci->nm.contents());
}

ligature_node::ligature_node(charinfo *c, tfont *t, 
                             node *gn1, node *gn2, node *x)
     : glyph_node(c, t, x), n1(gn1), n2(gn2)
{
}

#ifdef STORE_WIDTH
ligature_node::ligature_node(charinfo *c, tfont *t, hunits w,
                               node *gn1, node *gn2, node *x)
     : glyph_node(c, t, w, x), n1(gn1), n2(gn2)
{
}
#endif

ligature_node::~ligature_node()
{
  delete n1;
  delete n2;
}

node *ligature_node::copy()
{
#ifdef STORE_WIDTH
  return new ligature_node(ci, tf, wid, n1->copy(), n2->copy());
#else
  return new ligature_node(ci, tf, n1->copy(), n2->copy());
#endif
}

void ligature_node::ascii_print(ascii_output_file *ascii)
{
  n1->ascii_print(ascii);
  n2->ascii_print(ascii);
}

hyphen_list *ligature_node::get_hyphen_list(hyphen_list *tail)
{
  return n1->get_hyphen_list(n2->get_hyphen_list(tail));
}

node *ligature_node::add_self(node *n, hyphen_list **p)
{
  n = n1->add_self(n, p);
  n = n2->add_self(n, p);
  n1 = n2 = 0;
  delete this;
  return n;
}

kern_pair_node::kern_pair_node(hunits n, node *first, node *second, node *x)
     : node(x), n1(first), n2(second), amount(n)
{
}

dbreak_node::dbreak_node(node *n, node *p, node *x) 
     : node(x), none(n), pre(p), post(0)
{
}

node *dbreak_node::merge_glyph_node(glyph_node *gn)
{
  glyph_node *gn2 = (glyph_node *)gn->copy();
  node *new_none = none ? none->merge_glyph_node(gn) : 0;
  node *new_post = post ? post->merge_glyph_node(gn2) : 0;
  if (new_none == 0 && new_post == 0) {
    delete gn2;
    return 0;
  }
  if (new_none != 0)
    none = new_none;
  else {
    gn->next = none;
    none = gn;
  }
  if (new_post != 0)
    post = new_post;
  else {
    gn2->next = post;
    post = gn2;
  }
  return this;
}

node *kern_pair_node::merge_glyph_node(glyph_node *gn)
{
  node *nd = n2->merge_glyph_node(gn);
  if (nd == 0)
    return 0;
  n2 = nd;
  nd = n2->merge_self(n1);
  if (nd) {
    nd->next = next;
    n1 = 0;
    n2 = 0;
    delete this;
    return nd;
  }
  return this;
}


hunits kern_pair_node::italic_correction()
{
  return n2->italic_correction();
}

hunits kern_pair_node::subscript_correction()
{
  return n2->subscript_correction();
}

node *kern_pair_node::add_discretionary_hyphen()
{
  tfont *tf = n2->get_tfont();
  if (tf) {
    if (tf->contains(soft_hyphen_char)) {
      node *next1 = next;
      next = 0;
      node *n = copy();
      glyph_node *gn = new glyph_node(soft_hyphen_char, tf);
      node *nn = n->merge_glyph_node(gn);
      if (nn == 0) {
        gn->next = n;
        nn = gn;
      }
      return new dbreak_node(this, nn, next1);
    }
  }
  return this;
}


kern_pair_node::~kern_pair_node()
{
  if (n1 != 0)
    delete n1;
  if (n2 != 0)
    delete n2;
}

dbreak_node::~dbreak_node()
{
  delete_node_list(pre);
  delete_node_list(post);
  delete_node_list(none);
}

node *kern_pair_node::copy()
{
  return new kern_pair_node(amount, n1->copy(), n2->copy());
}

node *copy_node_list(node *n)
{
  node *p = 0;
  while (n != 0) {
    node *nn = n->copy();
    nn->next = p;
    p = nn;
    n = n->next;
  }
  while (p != 0) {
    node *pp = p->next;
    p->next = n;
    n = p;
    p = pp;
  }
  return n;
}

void delete_node_list(node *n)
{
  while (n != 0) {
    node *tem = n;
    n = n->next;
    delete tem;
  }
}

node *dbreak_node::copy()
{
  dbreak_node *p = new dbreak_node(copy_node_list(none), copy_node_list(pre));
  p->post = copy_node_list(post);
  return p;
}

hyphen_list *node::get_hyphen_list(hyphen_list *tail)
{
  return tail;
}


hyphen_list *kern_pair_node::get_hyphen_list(hyphen_list *tail)
{
  return n1->get_hyphen_list(n2->get_hyphen_list(tail));
}

class hyphen_inhibitor_node : public node {
public:
  hyphen_inhibitor_node(node *nd = 0);
  node *copy();
  int same(node *);
  const char *type();
  hyphenation_type get_hyphenation_type();
};

hyphen_inhibitor_node::hyphen_inhibitor_node(node *nd) : node(nd)
{
}

node *hyphen_inhibitor_node::copy()
{
  return new hyphen_inhibitor_node;
}

int hyphen_inhibitor_node::same(node *)
{
  return 1;
}

const char *hyphen_inhibitor_node::type()
{
  return "hyphen_inhibitor_node";
}

hyphenation_type hyphen_inhibitor_node::get_hyphenation_type()
{
  return HYPHEN_INHIBIT;
}

/* add_discretionary_hyphen methods */

node *dbreak_node::add_discretionary_hyphen()
{
  if (post)
    post = post->add_discretionary_hyphen();
  if (none)
    none = none->add_discretionary_hyphen();
  return this;
}


node *node::add_discretionary_hyphen()
{
  tfont *tf = get_tfont();
  if (!tf)
    return new hyphen_inhibitor_node(this);
  if (tf->contains(soft_hyphen_char)) {
    node *next1 = next;
    next = 0;
    node *n = copy();
    glyph_node *gn = new glyph_node(soft_hyphen_char, tf);
    node *n1 = n->merge_glyph_node(gn);
    if (n1 == 0) {
      gn->next = n;
      n1 = gn;
    }
    return new dbreak_node(this, n1, next1);
  }
  return this;
}


node *node::merge_self(node *)
{
  return 0;
}

node *node::add_self(node *n, hyphen_list ** /*p*/)
{
  next = n;
  return this;
}

node *kern_pair_node::add_self(node *n, hyphen_list **p)
{
  n = n1->add_self(n, p);
  n = n2->add_self(n, p);
  n1 = n2 = 0;
  delete this;
  return n;
}


hunits node::width()
{
  return H0;
}

node *node::last_char_node()
{
  return 0;
}

hunits hmotion_node::width()
{
  return n;
}

units node::size()
{
  return points_to_units(10);
}

hunits kern_pair_node::width()
{
  return n1->width() + n2->width() + amount;
}

node *kern_pair_node::last_char_node()
{
  node *nd = n2->last_char_node();
  if (nd)
    return nd;
  return n1->last_char_node();
}

hunits dbreak_node::width()
{
  hunits x = H0;
  for (node *n = none; n != 0; n = n->next)
    x += n->width();
  return x;
}

node *dbreak_node::last_char_node()
{
  for (node *n = none; n; n = n->next) {
    node *last = n->last_char_node();
    if (last)
      return last;
  }
  return 0;
}

hunits dbreak_node::italic_correction()
{
  return none ? none->italic_correction() : H0;
}

hunits dbreak_node::subscript_correction()
{
  return none ? none->subscript_correction() : H0;
}

class italic_corrected_node : public node {
  node *n;
  hunits x;
public:
  italic_corrected_node(node *, hunits, node * = 0);
  ~italic_corrected_node();
  node *copy();
  void ascii_print(ascii_output_file *);
  void asciify(macro *m);
  hunits width();
  node *last_char_node();
  void vertical_extent(vunits *, vunits *);
  int ends_sentence();
  int overlaps_horizontally();
  int overlaps_vertically();
  int same(node *);
  hyphenation_type get_hyphenation_type();
  tfont *get_tfont();
  hyphen_list *get_hyphen_list(hyphen_list *ss = 0);
  int character_type();
  void tprint(troff_output_file *);
  hunits subscript_correction();
  hunits skew();
  node *add_self(node *, hyphen_list **);
  const char *type();
};

node *node::add_italic_correction(hunits *width)
{
  hunits ic = italic_correction();
  if (ic.is_zero())
    return this;
  else {
    node *next1 = next;
    next = 0;
    *width += ic;
    return new italic_corrected_node(this, ic, next1);
  }
}

italic_corrected_node::italic_corrected_node(node *nn, hunits xx, node *p)
: n(nn), x(xx), node(p)
{
  assert(n != 0);
}

italic_corrected_node::~italic_corrected_node()
{
  delete n;
}

node *italic_corrected_node::copy()
{
  return new italic_corrected_node(n->copy(), x);
}

hunits italic_corrected_node::width()
{
  return n->width() + x;
}

void italic_corrected_node::vertical_extent(vunits *min, vunits *max)
{
  n->vertical_extent(min, max);
}

void italic_corrected_node::tprint(troff_output_file *out)
{
  n->tprint(out);
  out->right(x);
}

hunits italic_corrected_node::skew()
{
  return n->skew() - x/2;
}

hunits italic_corrected_node::subscript_correction()
{
  return n->subscript_correction() - x;
}

void italic_corrected_node::ascii_print(ascii_output_file *out)
{
  n->ascii_print(out);
}

int italic_corrected_node::ends_sentence()
{
  return n->ends_sentence();
}

int italic_corrected_node::overlaps_horizontally()
{
  return n->overlaps_horizontally();
}

int italic_corrected_node::overlaps_vertically()
{
  return n->overlaps_vertically();
}

node *italic_corrected_node::last_char_node()
{
  return n->last_char_node();
}

tfont *italic_corrected_node::get_tfont()
{
  return n->get_tfont();
}

hyphenation_type italic_corrected_node::get_hyphenation_type()
{
  return n->get_hyphenation_type();
}

node *italic_corrected_node::add_self(node *nd, hyphen_list **p)
{
  nd = n->add_self(nd, p);
  hunits not_interested;
  nd = nd->add_italic_correction(&not_interested);
  n = 0;
  delete this;
  return nd;
}

hyphen_list *italic_corrected_node::get_hyphen_list(hyphen_list *tail)
{
  return n->get_hyphen_list(tail);
}

int italic_corrected_node::character_type()
{
  return n->character_type();
}

class break_char_node : public node {
  node *ch;
  char break_code;
public:
  break_char_node(node *, int, node * = 0);
  ~break_char_node();
  node *copy();
  hunits width();
  vunits vertical_width();
  node *last_char_node();
  int character_type();
  int ends_sentence();
  node *add_self(node *, hyphen_list **);
  hyphen_list *get_hyphen_list(hyphen_list *s = 0);
  void tprint(troff_output_file *);
  void zero_width_tprint(troff_output_file *);
  void ascii_print(ascii_output_file *);
  void asciify(macro *m);
  hyphenation_type get_hyphenation_type();
  int overlaps_vertically();
  int overlaps_horizontally();
  units size();
  tfont *get_tfont();
  int same(node *);
  const char *type();
};

break_char_node::break_char_node(node *n, int c, node *x)
: node(x), ch(n), break_code(c)
{
}

break_char_node::~break_char_node()
{
  delete ch;
}

node *break_char_node::copy()
{
  return new break_char_node(ch->copy(), break_code);
}

hunits break_char_node::width()
{
  return ch->width();
}

vunits break_char_node::vertical_width()
{
  return ch->vertical_width();
}

node *break_char_node::last_char_node()
{
  return ch->last_char_node();
}

int break_char_node::character_type()
{
  return ch->character_type();
}

int break_char_node::ends_sentence()
{
  return ch->ends_sentence();
}

node *break_char_node::add_self(node *n, hyphen_list **p)
{
  assert((*p)->hyphenation_code == 0);
  if ((*p)->breakable && (break_code & 1)) {
    n = new space_node(H0, n);
    n->freeze_space();
  }
  next = n;
  n = this;
  if ((*p)->breakable && (break_code & 2)) {
    n = new space_node(H0, n);
    n->freeze_space();
  }
  hyphen_list *pp = *p;
  *p = (*p)->next;
  delete pp;
  return n;
}

hyphen_list *break_char_node::get_hyphen_list(hyphen_list *tail)
{
  return new hyphen_list(0, tail);
}

hyphenation_type break_char_node::get_hyphenation_type()
{
  return HYPHEN_MIDDLE;
}

void break_char_node::ascii_print(ascii_output_file *ascii)
{
  ch->ascii_print(ascii);
}

int break_char_node::overlaps_vertically()
{
  return ch->overlaps_vertically();
}

int break_char_node::overlaps_horizontally()
{
  return ch->overlaps_horizontally();
}

units break_char_node::size()
{
  return ch->size();
}

tfont *break_char_node::get_tfont()
{
  return ch->get_tfont();
}

node *extra_size_node::copy()
{ 
  return new extra_size_node(n); 
}

node *vertical_size_node::copy()
{ 
  return new vertical_size_node(n); 
}

node *hmotion_node::copy()
{ 
  return new hmotion_node(n);
}

node *space_char_hmotion_node::copy()
{
  return new space_char_hmotion_node(n);
}

node *vmotion_node::copy()
{ 
  return new vmotion_node(n);
}
  
node *dummy_node::copy()
{ 
  return new dummy_node;
}

node *transparent_dummy_node::copy()
{ 
  return new transparent_dummy_node;
}

hline_node::~hline_node()
{
  if (n)
    delete n;
}

node *hline_node::copy()
{
  return new hline_node(x, n ? n->copy() : 0);
}

hunits hline_node::width()
{
  return x < H0 ? H0 : x;
}


vline_node::~vline_node()
{
  if (n)
    delete n;
}

node *vline_node::copy()
{
  return new vline_node(x, n ? n->copy() : 0);
}

hunits vline_node::width()
{
  return n == 0 ? H0 : n->width();
}


zero_width_node::zero_width_node(node *nd) : n(nd)
{
}

zero_width_node::~zero_width_node()
{
  delete_node_list(n);
}

node *zero_width_node::copy()
{
  return new zero_width_node(copy_node_list(n));
}

int node_list_character_type(node *p)
{
  int t = 0;
  for (; p; p = p->next)
    t |= p->character_type();
  return t;
}

int zero_width_node::character_type()
{
  return node_list_character_type(n);
}

void node_list_vertical_extent(node *p, vunits *min, vunits *max)
{
  *min = V0;
  *max = V0;
  vunits cur_vpos = V0;
  vunits v1, v2;
  for (; p; p = p->next) {
    p->vertical_extent(&v1, &v2);
    v1 += cur_vpos;
    if (v1 < *min)
      *min = v1;
    v2 += cur_vpos;
    if (v2 > *max)
      *max = v2;
    cur_vpos += p->vertical_width();
  }
}

void zero_width_node::vertical_extent(vunits *min, vunits *max)
{
  node_list_vertical_extent(n, min, max);
}

overstrike_node::overstrike_node() : max_width(H0), list(0)
{
}

overstrike_node::~overstrike_node()
{
  delete_node_list(list);
}

node *overstrike_node::copy()
{
  overstrike_node *on = new overstrike_node;
  for (node *tem = list; tem; tem = tem->next)
    on->overstrike(tem->copy());
  return on;
}

void overstrike_node::overstrike(node *n)
{
  if (n == 0)
    return;
  hunits w = n->width();
  if (w > max_width)
    max_width = w;
  for (node **p = &list; *p; p = &(*p)->next)
    ;
  n->next = 0;
  *p = n;
}

hunits overstrike_node::width()
{
  return max_width;
}

bracket_node::bracket_node() : max_width(H0), list(0)
{
}

bracket_node::~bracket_node()
{
  delete_node_list(list);
}

node *bracket_node::copy()
{
  bracket_node *on = new bracket_node;
  for (node *tem = list; tem; tem = tem->next)
    on->bracket(tem->copy());
  return on;
}


void bracket_node::bracket(node *n)
{
  if (n == 0)
    return;
  hunits w = n->width();
  if (w > max_width)
    max_width = w;
  n->next = list;
  list = n;
}

hunits bracket_node::width()
{
  return max_width;
}

int node::nspaces()
{
  return 0;
}

int node::merge_space(hunits)
{
  return 0;
}

#if 0
space_node *space_node::free_list = 0;

void *space_node::operator new(size_t n)
{
  assert(n == sizeof(space_node));
  if (!free_list) {
    free_list = (space_node *)new char[sizeof(space_node)*BLOCK];
    for (int i = 0; i < BLOCK - 1; i++)
      free_list[i].next = free_list + i + 1;
    free_list[BLOCK-1].next = 0;
  }
  space_node *p = free_list;
  free_list = (space_node *)(free_list->next);
  p->next = 0;
  return p;
}

inline void space_node::operator delete(void *p)
{
  if (p) {
    ((space_node *)p)->next = free_list;
    free_list = (space_node *)p;
  }
}
#endif

space_node::space_node(hunits nn, node *p) : node(p), n(nn), set(0)
{
}

space_node::space_node(hunits nn, int s, node *p) : node(p), n(nn), set(s)
{
}

#if 0
space_node::~space_node()
{
}
#endif

node *space_node::copy()
{
  return new space_node(n, set);
}

int space_node::nspaces()
{
  return set ? 0 : 1;
}

int space_node::merge_space(hunits h)
{
  n += h;
  return 1;
}

hunits space_node::width()
{
  return n;
}

void node::spread_space(int*, hunits*)
{
}

void space_node::spread_space(int *nspaces, hunits *desired_space)
{
  if (!set) {
    assert(*nspaces > 0);
    if (*nspaces == 1) {
      n += *desired_space;
      *desired_space = H0;
    }
    else {
      hunits extra = *desired_space / *nspaces;
      *desired_space -= extra;
      n += extra;
    }
    *nspaces -= 1;
    set = 1;
  }
}

void node::freeze_space()
{
}

void space_node::freeze_space()
{
  set = 1;
}

diverted_space_node::diverted_space_node(vunits d, node *p)
: node(p), n(d)
{
}

node *diverted_space_node::copy()
{
  return new diverted_space_node(n);
}

diverted_copy_file_node::diverted_copy_file_node(symbol s, node *p)
: node(p), filename(s)
{
}

node *diverted_copy_file_node::copy()
{
  return new diverted_copy_file_node(filename);
}

int node::ends_sentence()
{
  return 0;
}

int kern_pair_node::ends_sentence()
{
  switch (n2->ends_sentence()) {
  case 0:
    return 0;
  case 1:
    return 1;
  case 2:
    break;
  default:
    assert(0);
  }
  return n1->ends_sentence();
}

int node_list_ends_sentence(node *n)
{
  for (; n != 0; n = n->next)
    switch (n->ends_sentence()) {
    case 0:
      return 0;
    case 1:
      return 1;
    case 2:
      break;
    default:
      assert(0);
    }
  return 2;
}

    
int dbreak_node::ends_sentence()
{
  return node_list_ends_sentence(none);
}


int node::overlaps_horizontally()
{
  return 0;
}

int node::overlaps_vertically()
{
  return 0;
}

int node::discardable()
{
  return 0;
}

int space_node::discardable()
{
  return set ? 0 : 1;
}


vunits node::vertical_width()
{
  return V0;
}

vunits vline_node::vertical_width()
{
  return x;
}

vunits vmotion_node::vertical_width()
{
  return n;
}

int node::character_type()
{
  return 0;
}

hunits node::subscript_correction()
{
  return H0;
}

hunits node::italic_correction()
{
  return H0;
}

hunits node::left_italic_correction()
{
  return H0;
}

hunits node::skew()
{
  return H0;
}


/* vertical_extent methods */

void node::vertical_extent(vunits *min, vunits *max)
{
  vunits v = vertical_width();
  if (v < V0) {
    *min = v;
    *max = V0;
  }
  else {
    *max = v;
    *min = V0;
  }
}

void vline_node::vertical_extent(vunits *min, vunits *max)
{
  if (n == 0)
    node::vertical_extent(min, max);
  else {
    vunits cmin, cmax;
    n->vertical_extent(&cmin, &cmax);
    vunits h = n->size();
    if (x < V0) {
      if (-x < h) {
        *min = x;
        *max = V0;
      }
      else {
        // we print the first character and then move up, so
        *max = cmax;
        // we print the last character and then move up h
        *min = cmin + h;
        if (*min > V0)
          *min = V0;
        *min += x;
      }
    }
    else {
      if (x < h) {
        *max = x;
        *min = V0;
      }
      else {
        // we move down by h and then print the first character, so
        *min = cmin + h;
        if (*min > V0)
          *min = V0;
        *max = x + cmax;
      }
    }
  }
}

/* ascii_print methods */


static void ascii_print_reverse_node_list(ascii_output_file *ascii, node *n)
{
  if (n == 0)
    return;
  ascii_print_reverse_node_list(ascii, n->next);
  n->ascii_print(ascii);
}

void dbreak_node::ascii_print(ascii_output_file *ascii)
{
  ascii_print_reverse_node_list(ascii, none);
}

void kern_pair_node::ascii_print(ascii_output_file *ascii)
{
  n1->ascii_print(ascii);
  n2->ascii_print(ascii);
}


void node::ascii_print(ascii_output_file *)
{
}

void space_node::ascii_print(ascii_output_file *ascii)
{
  if (!n.is_zero())
    ascii->outc(' ');
}

void hmotion_node::ascii_print(ascii_output_file *ascii)
{
  // this is pretty arbitrary
  if (n >= points_to_units(2))
    ascii->outc(' ');
}

void space_char_hmotion_node::ascii_print(ascii_output_file *ascii)
{
  ascii->outc(' ');
}

/* asciify methods */

void node::asciify(macro *m)
{
  m->append(this);
}
      
void glyph_node::asciify(macro *m)
{
  unsigned char c = ci->get_ascii_code();
  if (c != 0) {
    m->append(c);
    delete this;
  }
  else
    m->append(this);
}

void kern_pair_node::asciify(macro *m)
{
  n1->asciify(m);
  n2->asciify(m);
  n1 = n2 = 0;
  delete this;
}

static void asciify_reverse_node_list(macro *m, node *n)
{
  if (n == 0)
    return;
  asciify_reverse_node_list(m, n->next);
  n->asciify(m);
}

void dbreak_node::asciify(macro *m)
{
  asciify_reverse_node_list(m, none);
  none = 0;
  delete this;
}

void ligature_node::asciify(macro *m)
{
  n1->asciify(m);
  n2->asciify(m);
  n1 = n2 = 0;
  delete this;
}

void break_char_node::asciify(macro *m)
{
  ch->asciify(m);
  ch = 0;
  delete this;
}

void italic_corrected_node::asciify(macro *m)
{
  n->asciify(m);
  n = 0;
  delete this;
}

void left_italic_corrected_node::asciify(macro *m)
{
  if (n) {
    n->asciify(m);
    n = 0;
  }
  delete this;
}

space_char_hmotion_node::space_char_hmotion_node(hunits i, node *next)
: hmotion_node(i, next)
{
}

void space_char_hmotion_node::asciify(macro *m)
{
  m->append(' ');
  delete this;
}

void line_start_node::asciify(macro *)
{
  delete this;
}

void vertical_size_node::asciify(macro *)
{
  delete this;
}

breakpoint *node::get_breakpoints(hunits /*width*/, int /*nspaces*/,
                                  breakpoint *rest, int /*is_inner*/)
{
  return rest;
}

int node::nbreaks()
{
  return 0;
}

breakpoint *space_node::get_breakpoints(hunits width, int ns, breakpoint *rest,
                            int is_inner)
{
  if (next->discardable())
    return rest;
  breakpoint *bp = new breakpoint;
  bp->next = rest;
  bp->width = width;
  bp->nspaces = ns;
  bp->hyphenated = 0;
  if (is_inner) {
    assert(rest != 0);
    bp->index = rest->index + 1;
    bp->nd = rest->nd;
  }
  else {
    bp->nd = this;
    bp->index = 0;
  }
  return bp;
}

int space_node::nbreaks()
{
  if (next->discardable())
    return 0;
  else
    return 1;
}

static breakpoint *node_list_get_breakpoints(node *p, hunits *widthp,
                                             int ns, breakpoint *rest)
{
  if (p != 0) {
    rest = p->get_breakpoints(*widthp, 
                              ns, 
                              node_list_get_breakpoints(p->next, widthp, ns,
                                                        rest),
                              1);
    *widthp += p->width();
  }
  return rest;
}


breakpoint *dbreak_node::get_breakpoints(hunits width, int ns,
                                         breakpoint *rest, int is_inner)
{
  breakpoint *bp = new breakpoint;
  bp->next = rest;
  bp->width = width;
  for (node *tem = pre; tem != 0; tem = tem->next)
    bp->width += tem->width();
  bp->nspaces = ns;
  bp->hyphenated = 1;
  if (is_inner) {
    assert(rest != 0);
    bp->index = rest->index + 1;
    bp->nd = rest->nd;
  }
  else {
    bp->nd = this;
    bp->index = 0;
  }
  return node_list_get_breakpoints(none, &width, ns, bp);
}

int dbreak_node::nbreaks()
{
  int i = 1;
  for (node *tem = none; tem != 0; tem = tem->next)
    i += tem->nbreaks();
  return i;
}

void node::split(int /*where*/, node ** /*prep*/, node ** /*postp*/)
{
  assert(0);
}

void space_node::split(int where, node **pre, node **post)
{
  assert(where == 0);
  *pre = next;
  *post = 0;
  delete this;
}

static void node_list_split(node *p, int *wherep, node **prep, node **postp)
{
  if (p == 0)
    return;
  int nb = p->nbreaks();
  node_list_split(p->next, wherep, prep, postp);
  if (*wherep < 0) {
    p->next = *postp;
    *postp = p;
  }
  else if (*wherep < nb) {
    p->next = *prep;
    p->split(*wherep, prep, postp);
  }
  else {
    p->next = *prep;
    *prep = p;
  }
  *wherep -= nb;
}

void dbreak_node::split(int where, node **prep, node **postp)
{
  assert(where >= 0);
  if (where == 0) {
    *postp = post;
    post = 0;
    if (pre == 0)
      *prep = next;
    else {
      for (node *tem = pre; tem->next != 0; tem = tem->next)
        ;
      tem->next = next;
      *prep = pre;
    }
    pre = 0;
    delete this;
  }
  else {
    *prep = next;
    where -= 1;
    node_list_split(none, &where, prep, postp);
    none = 0;
    delete this;
  }
}
  

hyphenation_type node::get_hyphenation_type()
{
  return HYPHEN_BOUNDARY;
}


hyphenation_type dbreak_node::get_hyphenation_type()
{
  return HYPHEN_INHIBIT;
}

hyphenation_type kern_pair_node::get_hyphenation_type()
{
  return HYPHEN_MIDDLE;
}

hyphenation_type dummy_node::get_hyphenation_type()
{
  return HYPHEN_MIDDLE;
}

hyphenation_type transparent_dummy_node::get_hyphenation_type()
{
  return HYPHEN_MIDDLE;
}

int node::interpret(macro *)
{
  return 0;
}

special_node::special_node(const macro &m)
: mac(m)
{
}

int special_node::same(node *n)
{
  return mac == ((special_node *)n)->mac;
}

const char *special_node::type()
{
  return "special_node";
}

node *special_node::copy()
{
  return new special_node(mac);
}

void special_node::tprint_start(troff_output_file *out)
{
  out->start_special();
}

void special_node::tprint_char(troff_output_file *out, unsigned char c)
{
  out->special_char(c);
}

void special_node::tprint_end(troff_output_file *out)
{
  out->end_special();
}

/* composite_node */

class composite_node : public node {
  charinfo *ci;
  node *n;
  tfont *tf;
public:
  composite_node(node *, charinfo *, tfont *, node * = 0);
  ~composite_node();
  node *copy();
  hunits width();
  node *last_char_node();
  units size();
  void tprint(troff_output_file *);
  hyphenation_type get_hyphenation_type();
  int overlaps_horizontally();
  int overlaps_vertically();
  void ascii_print(ascii_output_file *);
  void asciify(macro *);
  hyphen_list *get_hyphen_list(hyphen_list *tail);
  node *add_self(node *, hyphen_list **);
  tfont *get_tfont();
  int same(node *);
  const char *type();
  void vertical_extent(vunits *, vunits *);
  vunits vertical_width();
};

composite_node::composite_node(node *p, charinfo *c, tfont *t, node *x)
: node(x), n(p), ci(c), tf(t)
{
}

composite_node::~composite_node()
{
  delete_node_list(n);
}

node *composite_node::copy()
{
  return new composite_node(copy_node_list(n), ci, tf);
}

hunits composite_node::width()
{
  hunits x;
  if (tf->get_constant_space(&x))
    return x;
  x = H0;
  for (node *tem = n; tem; tem = tem->next)
    x += tem->width();
  hunits offset;
  if (tf->get_bold(&offset))
    x += offset;
  x += tf->get_track_kern();
  return x;
}

node *composite_node::last_char_node()
{
  return this;
}

vunits composite_node::vertical_width()
{
  vunits v = V0;
  for (node *tem = n; tem; tem = tem->next)
    v += tem->vertical_width();
  return v;
}

units composite_node::size()
{
  return tf->get_size().to_units();
}

hyphenation_type composite_node::get_hyphenation_type()
{
  return HYPHEN_MIDDLE;
}

int composite_node::overlaps_horizontally()
{
  return ci->overlaps_horizontally();
}

int composite_node::overlaps_vertically()
{
  return ci->overlaps_vertically();
}

void composite_node::asciify(macro *m)
{
  unsigned char c = ci->get_ascii_code();
  if (c != 0) {
    m->append(c);
    delete this;
  }
  else
    m->append(this);
}

void composite_node::ascii_print(ascii_output_file *ascii)
{
  unsigned char c = ci->get_ascii_code();
  if (c != 0)
    ascii->outc(c);
  else
    ascii->outs(ci->nm.contents());

}

hyphen_list *composite_node::get_hyphen_list(hyphen_list *tail)
{
  return new hyphen_list(ci->get_hyphenation_code(), tail);

}

node *composite_node::add_self(node *nn, hyphen_list **p)
{
  assert(ci->get_hyphenation_code() == (*p)->hyphenation_code);
  next = nn;
  nn = this;
  if ((*p)->hyphen)
    nn = nn->add_discretionary_hyphen();
  hyphen_list *pp = *p;
  *p = (*p)->next;
  delete pp;
  return nn;
}

tfont *composite_node::get_tfont()
{
  return tf;
}

node *reverse_node_list(node *n)
{
  node *r = 0;
  while (n) {
    node *tem = n;
    n = n->next;
    tem->next = r;
    r = tem;
  }
  return r;
}

void composite_node::vertical_extent(vunits *min, vunits *max)
{
  n = reverse_node_list(n);
  node_list_vertical_extent(n, min, max);
  n = reverse_node_list(n);
}

word_space_node::word_space_node(hunits d, node *x) : space_node(d, x)
{
}

word_space_node::word_space_node(hunits d, int s, node *x)
: space_node(d, s, x)
{
}

node *word_space_node::copy()
{
  return new word_space_node(n, set);
}

void word_space_node::tprint(troff_output_file *out)
{
  out->word_marker();
  space_node::tprint(out);
}

unbreakable_space_node::unbreakable_space_node(hunits d, node *x)
: word_space_node(d, x)
{
}

unbreakable_space_node::unbreakable_space_node(hunits d, int s, node *x)
: word_space_node(d, s, x)
{
}

node *unbreakable_space_node::copy()
{
  return new unbreakable_space_node(n, set);
}

breakpoint *unbreakable_space_node::get_breakpoints(hunits, int,
                                                    breakpoint *rest, int)
{
  return rest;
}

int unbreakable_space_node::nbreaks()
{
  return 0;
}

void unbreakable_space_node::split(int, node **, node **)
{
  assert(0);
}

int unbreakable_space_node::merge_space(hunits)
{
  return 0;
}

hvpair::hvpair()
{
}

draw_node::draw_node(char c, hvpair *p, int np, font_size s)
     : code(c), npoints(np), sz(s)
{
  point = new hvpair[npoints];
  for (int i = 0; i < npoints; i++)
    point[i] = p[i];
}

int draw_node::same(node *n)
{
  draw_node *nd = (draw_node *)n;
  if (code != nd->code || npoints != nd->npoints || sz != nd->sz)
    return 0;
  for (int i = 0; i < npoints; i++)
    if (point[i].h != nd->point[i].h || point[i].v != nd->point[i].v)
      return 0;
  return 1;
}

const char *draw_node::type()
{
  return "draw_node";
}

draw_node::~draw_node()
{
  if (point)
    a_delete point;
}

hunits draw_node::width()
{
  hunits x = H0;
  for (int i = 0; i < npoints; i++)
    x += point[i].h;
  return x;
}

vunits draw_node::vertical_width()
{
  if (code == 'e')
    return V0;
  vunits x = V0;
  for (int i = 0; i < npoints; i++)
    x += point[i].v;
  return x;
}

node *draw_node::copy()
{
  return new draw_node(code, point, npoints, sz);
}

void draw_node::tprint(troff_output_file *out)
{
  out->draw(code, point, npoints, sz);
}
  
/* tprint methods */

void glyph_node::tprint(troff_output_file *out)
{
  tfont *ptf = tf->get_plain();
  if (ptf == tf)
    out->put_char_width(ci, ptf, width(), H0);
  else {
    hunits offset;
    int bold = tf->get_bold(&offset);
    hunits w = ptf->get_width(ci);
    hunits k = H0;
    hunits x;
    int cs = tf->get_constant_space(&x);
    if (cs) {
      x -= w;
      if (bold)
        x -= offset;
      hunits x2 = x/2;
      out->right(x2);
      k = x - x2;
    }
    else
      k = tf->get_track_kern();
    if (bold) {
      out->put_char(ci, ptf);
      out->right(offset);
    }
    out->put_char_width(ci, ptf, w, k);
  }
}

void glyph_node::zero_width_tprint(troff_output_file *out)
{
  tfont *ptf = tf->get_plain();
  hunits offset;
  int bold = tf->get_bold(&offset);
  hunits x;
  int cs = tf->get_constant_space(&x);
  if (cs) {
    x -= ptf->get_width(ci);
    if (bold)
      x -= offset;
    x = x/2;
    out->right(x);
  }
  out->put_char(ci, ptf);
  if (bold) {
    out->right(offset);
    out->put_char(ci, ptf);
    out->right(-offset);
  }
  if (cs)
    out->right(-x);
}

void break_char_node::tprint(troff_output_file *t)
{
  ch->tprint(t);
}

void break_char_node::zero_width_tprint(troff_output_file *t)
{
  ch->zero_width_tprint(t);
}

void hline_node::tprint(troff_output_file *out)
{
  if (x < H0) {
    out->right(x);
    x = -x;
  }
  if (n == 0) {
    out->right(x);
    return;
  }
  hunits w = n->width();
  if (w <= H0) {
    error("horizontal line drawing character must have positive width");
    out->right(x);
    return;
  }
  int i = int(x/w);
  if (i == 0) {
    hunits xx = x - w;
    hunits xx2 = xx/2;
    out->right(xx2);
    n->tprint(out);
    out->right(xx - xx2);
  }
  else {
    hunits rem = x - w*i;
    if (rem > H0)
      if (n->overlaps_horizontally()) {
        n->tprint(out);
        out->right(rem - w);
      }
      else
        out->right(rem);
    while (--i >= 0)
      n->tprint(out);
  }
}

void vline_node::tprint(troff_output_file *out)
{
  if (n == 0) {
    out->down(x);
    return;
  }
  vunits h = n->size();
  int overlaps = n->overlaps_vertically();
  vunits y = x;
  if (y < V0) {
    y = -y;
    int i = y / h;
    vunits rem = y - i*h;
    if (i == 0) {
      out->right(n->width());
      out->down(-rem);
    }
    else {
      while (--i > 0) {
        n->zero_width_tprint(out);
        out->down(-h);
      }
      if (overlaps) {
        n->zero_width_tprint(out);
        out->down(-rem);
        n->tprint(out);
        out->down(-h);
      }
      else {
        n->tprint(out);
        out->down(-h - rem);
      }
    }
  }
  else {
    int i = y / h;
    vunits rem = y - i*h;
    if (i == 0) {
      out->down(rem);
      out->right(n->width());
    }
    else {
      out->down(h);
      if (overlaps)
        n->zero_width_tprint(out);
      out->down(rem);
      while (--i > 0) {
        n->zero_width_tprint(out);
        out->down(h);
      }
      n->tprint(out);
    }
  }
}

void zero_width_node::tprint(troff_output_file *out)
{
  if (!n)
    return;
  if (!n->next) {
    n->zero_width_tprint(out);
    return;
  }
  int hpos = out->get_hpos();
  int vpos = out->get_vpos();
  node *tem = n;
  while (tem) {
    tem->tprint(out);
    tem = tem->next;
  }
  out->moveto(hpos, vpos);
}

void overstrike_node::tprint(troff_output_file *out)
{
  hunits pos = H0;
  for (node *tem = list; tem; tem = tem->next) {
    hunits x = (max_width - tem->width())/2;
    out->right(x - pos);
    pos = x;
    tem->zero_width_tprint(out);
  }
  out->right(max_width - pos);
}

void bracket_node::tprint(troff_output_file *out)
{
  if (list == 0)
    return;
  int npieces = 0;
  for (node *tem = list; tem; tem = tem->next)
    ++npieces;
  vunits h = list->size();
  vunits totalh = h*npieces;
  vunits y = (totalh - h)/2;
  out->down(y);
  for (tem = list; tem; tem = tem->next) {
    tem->zero_width_tprint(out);
    out->down(-h);
  }
  out->right(max_width);
  out->down(totalh - y);
}

void node::tprint(troff_output_file *)
{
}

void node::zero_width_tprint(troff_output_file *out)
{
  int hpos = out->get_hpos();
  int vpos = out->get_vpos();
  tprint(out);
  out->moveto(hpos, vpos);
}

void space_node::tprint(troff_output_file *out)
{
  out->right(n);
}

void hmotion_node::tprint(troff_output_file *out)
{
  out->right(n);
}

void vmotion_node::tprint(troff_output_file *out)
{
  out->down(n);
}

void kern_pair_node::tprint(troff_output_file *out)
{
  n1->tprint(out);
  out->right(amount);
  n2->tprint(out);
}

static void tprint_reverse_node_list(troff_output_file *out, node *n)
{
  if (n == 0)
    return;
  tprint_reverse_node_list(out, n->next);
  n->tprint(out);
}

void dbreak_node::tprint(troff_output_file *out)
{
  tprint_reverse_node_list(out, none);
}

void composite_node::tprint(troff_output_file *out)
{
  hunits bold_offset;
  int is_bold = tf->get_bold(&bold_offset);
  hunits track_kern = tf->get_track_kern();
  hunits constant_space;
  int is_constant_spaced = tf->get_constant_space(&constant_space);
  hunits x = H0;
  if (is_constant_spaced) {
    x = constant_space;
    for (node *tem = n; tem; tem = tem->next)
      x -= tem->width();
    if (is_bold)
      x -= bold_offset;
    hunits x2 = x/2;
    out->right(x2);
    x -= x2;
  }
  if (is_bold) {
    int hpos = out->get_hpos();
    int vpos = out->get_vpos();
    tprint_reverse_node_list(out, n);
    out->moveto(hpos, vpos);
    out->right(bold_offset);
  }
  tprint_reverse_node_list(out, n);
  if (is_constant_spaced)
    out->right(x);
  else
    out->right(track_kern);
}

node *make_composite_node(charinfo *s, environment *env)
{
  int fontno = env_definite_font(env);
  if (fontno < 0) {
    error("no current font");
    return 0;
  }
  assert(fontno < font_table_size && font_table[fontno] != 0);
  node *n = charinfo_to_node_list(s, env);
  font_size fs = env->get_font_size();
  int char_height = env->get_char_height();
  int char_slant = env->get_char_slant();
  tfont *tf = font_table[fontno]->get_tfont(fs, char_height, char_slant,
                                            fontno);
  if (env->is_composite())
    tf = tf->get_plain();
  return new composite_node(n, s, tf);
}

node *make_glyph_node(charinfo *s, environment *env, int no_error_message = 0)
{
  int fontno = env_definite_font(env);
  if (fontno < 0) {
    error("no current font");
    return 0;
  }
  assert(fontno < font_table_size && font_table[fontno] != 0);
  int fn = fontno;
  int found = font_table[fontno]->contains(s);
  if (!found) {
    if (s->numbered()) {
      if (!no_error_message)
        warning(WARN_CHAR, "can't find numbered character %1",
                s->get_number());
      return 0;
    }
    special_font_list *sf = font_table[fontno]->sf;
    while (sf != 0 && !found) {
      fn = sf->n;
      if (font_table[fn])
        found = font_table[fn]->contains(s);
      sf = sf->next;
    }
    if (!found) {
      sf = global_special_fonts;
      while (sf != 0 && !found) {
        fn = sf->n;
        if (font_table[fn])
          found = font_table[fn]->contains(s);
        sf = sf->next;
      }
    }
    if (!found
#if 0   
        && global_special_fonts == 0 && font_table[fontno]->sf == 0
#endif
        ) {
      for (fn = 0; fn < font_table_size; fn++)
        if (font_table[fn] 
            && font_table[fn]->is_special()
            && font_table[fn]->contains(s)) {
              found = 1;
              break;
            }
    }
    if (!found) {
      if (!no_error_message && s->first_time_not_found()) {
        unsigned char input_code = s->get_ascii_code();
        if (input_code != 0) {
          if (csgraph(input_code))
            warning(WARN_CHAR, "can't find character `%1'", input_code);
          else
            warning(WARN_CHAR, "can't find character with input code %1",
                    int(input_code));
        }
        else
          warning(WARN_CHAR, "can't find special character `%1'",
                  s->nm.contents());
      }
      return 0;
    }
  }
  font_size fs = env->get_font_size();
  int char_height = env->get_char_height();
  int char_slant = env->get_char_slant();
  tfont *tf = font_table[fontno]->get_tfont(fs, char_height, char_slant, fn);
  if (env->is_composite())
    tf = tf->get_plain();
  return new glyph_node(s, tf);
}

node *make_node(charinfo *ci, environment *env)
{
  switch (ci->get_special_translation()) {
  case charinfo::TRANSLATE_SPACE:
    return new space_char_hmotion_node(env->get_space_width());
  case charinfo::TRANSLATE_DUMMY:
    return new dummy_node;
  case charinfo::TRANSLATE_HYPHEN_INDICATOR:
    error("translation to \\% ignored in this context");
    break;
  }
  charinfo *tem = ci->get_translation();
  if (tem)
    ci = tem;
  macro *mac = ci->get_macro();
  if (mac)
    return make_composite_node(ci, env);
  else
    return make_glyph_node(ci, env);
}

int character_exists(charinfo *ci, environment *env)
{
  if (ci->get_special_translation() != charinfo::TRANSLATE_NONE)
    return 1;
  charinfo *tem = ci->get_translation();
  if (tem)
    ci = tem;
  if (ci->get_macro())
    return 1;
  node *nd = make_glyph_node(ci, env, 1);
  if (nd) {
    delete nd;
    return 1;
  }
  return 0;
}

node *node::add_char(charinfo *ci, environment *env, hunits *widthp)
{
  node *res;
  switch (ci->get_special_translation()) {
  case charinfo::TRANSLATE_SPACE:
    res = new space_char_hmotion_node(env->get_space_width(), this);
    *widthp += res->width();
    return res;
  case charinfo::TRANSLATE_DUMMY:
    return new dummy_node(this);
  case charinfo::TRANSLATE_HYPHEN_INDICATOR:
    return add_discretionary_hyphen();
  }
  charinfo *tem = ci->get_translation();
  if (tem)
    ci = tem;
  macro *mac = ci->get_macro();
  if (mac) {
    res = make_composite_node(ci, env);
    if (res) {
      res->next = this;
      *widthp += res->width();
    }
    else
      return this;
  }
  else {
    node *gn = make_glyph_node(ci, env);
    if (gn == 0)
      return this;
    else {
      hunits old_width = width();
      node *p = gn->merge_self(this);
      if (p == 0) {
        *widthp += gn->width();
        gn->next = this;
        res = gn;
      }
      else {
        *widthp += p->width() - old_width;
        res = p;
      }
    }
  }
  int break_code = 0;
  if (ci->can_break_before())
    break_code = 1;
  if (ci->can_break_after())
    break_code |= 2;
  if (break_code) {
    node *next1 = res->next;
    res->next = 0;
    res = new break_char_node(res, break_code, next1);
  }
  return res;
}


#ifdef __GNUG__
inline
#endif
int same_node(node *n1, node *n2)
{
  if (n1 != 0) {
    if (n2 != 0)
      return n1->type() == n2->type() && n1->same(n2);
    else
      return 0;
  }
  else
    return n2 == 0;
}

int same_node_list(node *n1, node *n2)
{
  while (n1 && n2) {
    if (n1->type() != n2->type() || !n1->same(n2))
      return 0;
    n1 = n1->next;
    n2 = n2->next;
  }
  return !n1 && !n2;
}

int extra_size_node::same(node *nd)
{
  return n == ((extra_size_node *)nd)->n;
}

const char *extra_size_node::type()
{
  return "extra_size_node";
}

int vertical_size_node::same(node *nd)
{
  return n == ((vertical_size_node *)nd)->n;
}

const char *vertical_size_node::type()
{
  return "vertical_size_node";
}

int hmotion_node::same(node *nd)
{
  return n == ((hmotion_node *)nd)->n;
}

const char *hmotion_node::type()
{
  return "hmotion_node";
}

int space_char_hmotion_node::same(node *nd)
{
  return n == ((space_char_hmotion_node *)nd)->n;
}

const char *space_char_hmotion_node::type()
{
  return "space_char_hmotion_node";
}

int vmotion_node::same(node *nd)
{
  return n == ((vmotion_node *)nd)->n;
}

const char *vmotion_node::type()
{
  return "vmotion_node";
}

int hline_node::same(node *nd)
{
  return x == ((hline_node *)nd)->x && same_node(n, ((hline_node *)nd)->n);
}

const char *hline_node::type()
{
  return "hline_node";
}

int vline_node::same(node *nd)
{
  return x == ((vline_node *)nd)->x && same_node(n, ((vline_node *)nd)->n);
}

const char *vline_node::type()
{
  return "vline_node";
}

int dummy_node::same(node * /*nd*/)
{
  return 1;
}

const char *dummy_node::type()
{
  return "dummy_node";
}

int transparent_dummy_node::same(node * /*nd*/)
{
  return 1;
}

const char *transparent_dummy_node::type()
{
  return "transparent_dummy_node";
}

int transparent_dummy_node::ends_sentence()
{
  return 2;
}

int zero_width_node::same(node *nd)
{
  return same_node_list(n, ((zero_width_node *)nd)->n);
}

const char *zero_width_node::type()
{
  return "zero_width_node";
}

int italic_corrected_node::same(node *nd)
{
  return (x == ((italic_corrected_node *)nd)->x
          && same_node(n, ((italic_corrected_node *)nd)->n));
}

const char *italic_corrected_node::type()
{
  return "italic_corrected_node";
}


left_italic_corrected_node::left_italic_corrected_node(node *x)
: n(0), node(x)
{
}

left_italic_corrected_node::~left_italic_corrected_node()
{
  delete n;
}

node *left_italic_corrected_node::merge_glyph_node(glyph_node *gn)
{
  if (n == 0) {
    hunits lic = gn->left_italic_correction();
    if (!lic.is_zero()) {
      x = lic;
      n = gn;
      return this;
    }
  }
  else {
    node *nd = n->merge_glyph_node(gn);
    if (nd) {
      n = nd;
      x = n->left_italic_correction();
      return this;
    }
  }
  return 0;
}

node *left_italic_corrected_node::copy()
{
  left_italic_corrected_node *nd = new left_italic_corrected_node;
  if (n) {
    nd->n = n->copy();
    nd->x = x;
  }
  return nd;
}

void left_italic_corrected_node::tprint(troff_output_file *out)
{
  if (n) {
    out->right(x);
    n->tprint(out);
  }
}

const char *left_italic_corrected_node::type()
{
  return "left_italic_corrected_node";
}

int left_italic_corrected_node::same(node *nd)
{
  return (x == ((left_italic_corrected_node *)nd)->x
          && same_node(n, ((left_italic_corrected_node *)nd)->n));
}

void left_italic_corrected_node::ascii_print(ascii_output_file *out)
{
  if (n)
    n->ascii_print(out);
}

hunits left_italic_corrected_node::width()
{
  return n ? n->width() + x : H0;
}

void left_italic_corrected_node::vertical_extent(vunits *min, vunits *max)
{
  if (n)
    n->vertical_extent(min, max);
  else
    node::vertical_extent(min, max);
}

hunits left_italic_corrected_node::skew()
{
  return n ? n->skew() + x/2 : H0;
}

hunits left_italic_corrected_node::subscript_correction()
{
  return n ? n->subscript_correction() : H0;
}

hunits left_italic_corrected_node::italic_correction()
{
  return n ? n->italic_correction() : H0;
}

int left_italic_corrected_node::ends_sentence()
{
  return n ? n->ends_sentence() : 0;
}

int left_italic_corrected_node::overlaps_horizontally()
{
  return n ? n->overlaps_horizontally() : 0;
}

int left_italic_corrected_node::overlaps_vertically()
{
  return n ? n->overlaps_vertically() : 0;
}

node *left_italic_corrected_node::last_char_node()
{
  return n ? n->last_char_node() : 0;
}

tfont *left_italic_corrected_node::get_tfont()
{
  return n ? n->get_tfont() : 0;
}

hyphenation_type left_italic_corrected_node::get_hyphenation_type()
{
  if (n)
    return n->get_hyphenation_type();
  else
    return HYPHEN_MIDDLE;
}

hyphen_list *left_italic_corrected_node::get_hyphen_list(hyphen_list *tail)
{
  return n ? n->get_hyphen_list(tail) : tail;
}

node *left_italic_corrected_node::add_self(node *nd, hyphen_list **p)
{
  if (n) {
    nd = new left_italic_corrected_node(nd);
    nd = n->add_self(nd, p);
    n = 0;
    delete this;
  }
  return nd;
}

int left_italic_corrected_node::character_type()
{
  return n ? n->character_type() : 0;
}
 
int overstrike_node::same(node *nd)
{
  return same_node_list(list, ((overstrike_node *)nd)->list);
}

const char *overstrike_node::type()
{
  return "overstrike_node";
}

int bracket_node::same(node *nd)
{
  return same_node_list(list, ((bracket_node *)nd)->list);
}

const char *bracket_node::type()
{
  return "bracket_node";
}

int composite_node::same(node *nd)
{
  return ci == ((composite_node *)nd)->ci
    && same_node_list(n, ((composite_node *)nd)->n);
}

const char *composite_node::type()
{
  return "composite_node";
}

int glyph_node::same(node *nd)
{
  return ci == ((glyph_node *)nd)->ci && tf == ((glyph_node *)nd)->tf;
}

const char *glyph_node::type()
{
  return "glyph_node";
}

int ligature_node::same(node *nd)
{
  return (same_node(n1, ((ligature_node *)nd)->n1) 
          && same_node(n2, ((ligature_node *)nd)->n2)
          && glyph_node::same(nd));
}

const char *ligature_node::type()
{
  return "ligature_node";
}

int kern_pair_node::same(node *nd)
{
  return (amount == ((kern_pair_node *)nd)->amount
          && same_node(n1, ((kern_pair_node *)nd)->n1)
          && same_node(n2, ((kern_pair_node *)nd)->n2));
}

const char *kern_pair_node::type()
{
  return "kern_pair_node";
}

int dbreak_node::same(node *nd)
{
  return (same_node_list(none, ((dbreak_node *)nd)->none)
          && same_node_list(pre, ((dbreak_node *)nd)->pre)
          && same_node_list(post, ((dbreak_node *)nd)->post));
}

const char *dbreak_node::type()
{
  return "dbreak_node";
}

int break_char_node::same(node *nd)
{
  return (break_code == ((break_char_node *)nd)->break_code
          && same_node(ch, ((break_char_node *)nd)->ch));
}

const char *break_char_node::type()
{
  return "break_char_node";
}

int line_start_node::same(node * /*nd*/)
{
  return 1;
}

const char *line_start_node::type()
{
  return "line_start_node";
}

int space_node::same(node *nd)
{
  return n == ((space_node *)nd)->n && set == ((space_node *)nd)->set;
}

const char *space_node::type()
{
  return "space_node";
}

int word_space_node::same(node *nd)
{
  return (n == ((word_space_node *)nd)->n
          && set == ((word_space_node *)nd)->set);
}

const char *word_space_node::type()
{
  return "word_space_node";
}

int unbreakable_space_node::same(node *nd)
{
  return (n == ((unbreakable_space_node *)nd)->n
          && set == ((unbreakable_space_node *)nd)->set);
}

const char *unbreakable_space_node::type()
{
  return "unbreakable_space_node";
}

int diverted_space_node::same(node *nd)
{
  return n == ((diverted_space_node *)nd)->n;
}

const char *diverted_space_node::type()
{
  return "diverted_space_node";
}

int diverted_copy_file_node::same(node *nd)
{
  return filename == ((diverted_copy_file_node *)nd)->filename;
}

const char *diverted_copy_file_node::type()
{
  return "diverted_copy_file_node";
}

// Grow the font_table so that its size is > n.

static void grow_font_table(int n)
{
  assert(n >= font_table_size);
  font_info **old_font_table = font_table;
  int old_font_table_size = font_table_size;
  font_table_size = font_table_size ? (font_table_size*3)/2 : 10;
  if (font_table_size <= n)
    font_table_size = n + 10;
  font_table = new font_info *[font_table_size];
  if (old_font_table_size)
    memcpy(font_table, old_font_table,
           old_font_table_size*sizeof(font_info *));
  a_delete old_font_table;
  for (int i = old_font_table_size; i < font_table_size; i++)
    font_table[i] = 0;
}

dictionary font_translation_dictionary(17);

static symbol get_font_translation(symbol nm)
{
  void *p = font_translation_dictionary.lookup(nm);
  return p ? symbol((char *)p) : nm;
}

dictionary font_dictionary(50);

static int mount_font_no_translate(int n, symbol name, symbol external_name)
{
  assert(n >= 0);
  // We store the address of this char in font_dictionary to indicate
  // that we've previously tried to mount the font and failed.
  static char a_char;
  font *fm = 0;
  void *p = font_dictionary.lookup(external_name);
  if (p == 0) {
    int not_found;
    fm = font::load_font(external_name.contents(), &not_found);
    if (!fm) {
      if (not_found)
        warning(WARN_FONT, "can't find font `%1'", external_name.contents());
      font_dictionary.lookup(external_name, &a_char);
      return 0;
    }
    font_dictionary.lookup(name, fm);
  }
  else if (p == &a_char) {
#if 0
    error("invalid font `%1'", external_name.contents());
#endif
    return 0;
  }
  else
    fm = (font*)p;
  if (n >= font_table_size) {
    if (n - font_table_size > 1000) {
      error("font position too much larger than first unused position");
      return 0;
    }
    grow_font_table(n);
  }
  else if (font_table[n] != 0)
    delete font_table[n];
  font_table[n] = new font_info(name, n, external_name, fm);
  invalidate_fontno(n);
  return 1;
}

int mount_font(int n, symbol name, symbol external_name)
{
  assert(n >= 0);
  name = get_font_translation(name);
  if (external_name.is_null())
    external_name = name;
  else
    external_name = get_font_translation(external_name);
  return mount_font_no_translate(n, name, external_name);
}

void mount_style(int n, symbol name)
{
  assert(n >= 0);
  if (n >= font_table_size) {
    if (n - font_table_size > 1000) {
      error("font position too much larger than first unused position");
      return;
    }
    grow_font_table(n);
  }
  else if (font_table[n] != 0)
    delete font_table[n];
  font_table[n] = new font_info(get_font_translation(name), n, NULL_SYMBOL, 0);
  invalidate_fontno(n);
}

/* global functions */

void font_translate()
{
  symbol from = get_name(1);
  if (!from.is_null()) {
    symbol to = get_name();
    if (to.is_null() || from == to)
      font_translation_dictionary.remove(from);
    else
      font_translation_dictionary.lookup(from, (void *)to.contents());
  }
  skip_line();
}

void font_position()
{
  int n;
  if (get_integer(&n)) {
    if (n < 0)
      error("negative font position");
    else {
      symbol internal_name = get_name(1);
      if (!internal_name.is_null()) {
        symbol external_name = get_long_name(0);
        mount_font(n, internal_name, external_name); // ignore error
      }
    }
  }
  skip_line();
}

font_family::font_family(symbol s)
: nm(s), map_size(10)
{
  map = new int[map_size];
  for (int i = 0; i < map_size; i++)
    map[i] = -1;
}

font_family::~font_family()
{
  a_delete map;
}

int font_family::make_definite(int i)
{
  if (i >= 0) {
    if (i < map_size && map[i] >= 0)
      return map[i];
    else {
      if (i < font_table_size && font_table[i] != 0) {
        if (i >= map_size) {
          int old_map_size = map_size;
          int *old_map = map;
          map_size *= 3;
          map_size /= 2;
          if (i >= map_size)
            map_size = i + 10;
          map = new int[map_size];
          memcpy(map, old_map, old_map_size*sizeof(int));
          a_delete old_map;
          for (int j = old_map_size; j < map_size; j++)
            map[j] = -1;
        }
        if (font_table[i]->is_style()) {
          symbol sty = font_table[i]->get_name();
          symbol f = concat(nm, sty);
          int n;
          // don't use symbol_fontno, because that might return a style
          // and because we don't want to translate the name
          for (n = 0; n < font_table_size; n++)
            if (font_table[n] != 0 && font_table[n]->is_named(f)
                && !font_table[n]->is_style())
              break;
          if (n >= font_table_size) {
            n = next_available_font_position();
            if (!mount_font_no_translate(n, f, f))
              return -1;
          }
          return map[i] = n;
        }
        else
          return map[i] = i;
      }
      else
        return -1;
    }
  }
  else
    return -1;
}

dictionary family_dictionary(5);

font_family *lookup_family(symbol nm)
{
  font_family *f = (font_family *)family_dictionary.lookup(nm);
  if (!f) {
    f = new font_family(nm);
    (void)family_dictionary.lookup(nm, f);
  }
  return f;
} 

static void invalidate_fontno(int n)
{
  assert(n >= 0 && n < font_table_size);
  dictionary_iterator iter(family_dictionary);
  symbol nm;
  font_family *fam;
  while (iter.get(&nm, (void **)&fam)) {
    int map_size = fam->map_size;
    if (n < map_size)
      fam->map[n] = -1;
    for (int i = 0; i < map_size; i++)
      if (fam->map[i] == n)
        fam->map[i] = -1;
  }
}

void style()
{
  int n;
  if (get_integer(&n)) {
    if (n < 0)
      error("negative font position");
    else {
      symbol internal_name = get_name(1);
      if (!internal_name.is_null())
        mount_style(n, internal_name);
    }
  }
  skip_line();
}

static int get_fontno()
{
  int n;
  tok.skip();
  if (tok.delimiter()) {
    symbol s = get_name(1);
    if (!s.is_null()) {
      n = symbol_fontno(s);
      if (n < 0) {
        n = next_available_font_position();
        if (!mount_font(n, s))
          return -1;
      }
      return curenv->get_family()->make_definite(n);
    }
  }
  else if (get_integer(&n)) {
    if (n < 0 || n >= font_table_size || font_table[n] == 0)
      error("bad font number");
    else
      return curenv->get_family()->make_definite(n);
  }
  return -1;
}

static int underline_fontno = 2;

void underline_font()
{
  int n = get_fontno();
  if (n >= 0)
    underline_fontno = n;
  skip_line();
}

int get_underline_fontno()
{
  return underline_fontno;
}
    
static void read_special_fonts(special_font_list **sp)
{
  special_font_list *s = *sp;
  *sp = 0;
  while (s != 0) {
    special_font_list *tem = s;
    s = s->next;
    delete tem;
  }
  special_font_list **p = sp;
  while (has_arg()) {
    int i = get_fontno();
    if (i >= 0) {
      special_font_list *tem = new special_font_list;
      tem->n = i;
      tem->next = 0;
      *p = tem;
      p = &(tem->next);
    }
  }
}

void font_special_request()
{
  int n = get_fontno();
  if (n >= 0)
    read_special_fonts(&font_table[n]->sf); 
  skip_line();
}

  
void special_request()
{
  read_special_fonts(&global_special_fonts);
  skip_line();
}

int next_available_font_position()
{
  for (int i = 1; i < font_table_size && font_table[i] != 0; i++)
    ;
  return i;
}

int symbol_fontno(symbol s)
{
  s = get_font_translation(s);
  for (int i = 0; i < font_table_size; i++)
    if (font_table[i] != 0 && font_table[i]->is_named(s))
      return i;
  return -1;
}

int is_good_fontno(int n)
{
  return n >= 0 && n < font_table_size && font_table[n] != NULL;
}

int get_bold_fontno(int n)
{
  if (n >= 0 && n < font_table_size && font_table[n] != 0) {
    hunits offset;
    if (font_table[n]->get_bold(&offset))
      return offset.to_units() + 1;
    else
      return 0;
  }
  else
    return 0;
}

hunits env_digit_width(environment *env)
{
  node *n = make_glyph_node(charset_table['0'], env);
  if (n) {
    hunits x = n->width();
    delete n;
    return x;
  }
  else
    return H0;
}

hunits env_space_width(environment *env)
{
  int fn = env_definite_font(env);
  font_size fs = env->get_font_size();
  if (fn < 0 || fn >= font_table_size || font_table[fn] == 0)
    return scale(fs.to_units()/3, env->get_space_size(), 12);
  else
    return font_table[fn]->get_space_width(fs, env->get_space_size());
}

hunits env_sentence_space_width(environment *env)
{
  int fn = env_definite_font(env);
  font_size fs = env->get_font_size();
  if (fn < 0 || fn >= font_table_size || font_table[fn] == 0)
    return scale(fs.to_units()/3, env->get_sentence_space_size(), 12);
  else
    return font_table[fn]->get_space_width(fs, env->get_sentence_space_size());
}

hunits env_half_narrow_space_width(environment *env)
{
  int fn = env_definite_font(env);
  font_size fs = env->get_font_size();
  if (fn < 0 || fn >= font_table_size || font_table[fn] == 0)
    return 0;
  else
    return font_table[fn]->get_half_narrow_space_width(fs);
}

hunits env_narrow_space_width(environment *env)
{
  int fn = env_definite_font(env);
  font_size fs = env->get_font_size();
  if (fn < 0 || fn >= font_table_size || font_table[fn] == 0)
    return 0;
  else
    return font_table[fn]->get_narrow_space_width(fs);
}

void bold_font()
{
  int n = get_fontno();
  if (n >= 0) {
    if (has_arg()) {
      if (tok.delimiter()) {
        int f = get_fontno();
        if (f >= 0) {
          units offset;
          if (has_arg() && get_number(&offset, 'u') && offset >= 1)
            font_table[f]->set_conditional_bold(n, hunits(offset - 1));
          else
            font_table[f]->conditional_unbold(n);
        }
      }
      else {
        units offset;
        if (get_number(&offset, 'u') && offset >= 1)
          font_table[n]->set_bold(hunits(offset - 1));
        else
          font_table[n]->unbold();
      }
    }
    else
      font_table[n]->unbold();
  }
  skip_line();
}

track_kerning_function::track_kerning_function() : non_zero(0)
{
}

track_kerning_function::track_kerning_function(int min_s, hunits min_a, 
                                               int max_s, hunits max_a)
     : non_zero(1), 
     min_size(min_s), min_amount(min_a),
     max_size(max_s), max_amount(max_a)
{
}

int track_kerning_function::operator==(const track_kerning_function &tk)
{
  if (non_zero)
    return (tk.non_zero
            && min_size == tk.min_size
            && min_amount == tk.min_amount
            && max_size == tk.max_size
            && max_amount == tk.max_amount);
  else
    return !tk.non_zero;
}

int track_kerning_function::operator!=(const track_kerning_function &tk)
{
  if (non_zero)
    return (!tk.non_zero
            || min_size != tk.min_size
            || min_amount != tk.min_amount
            || max_size != tk.max_size
            || max_amount != tk.max_amount);
  else
    return tk.non_zero;
}

hunits track_kerning_function::compute(int size)
{
  if (non_zero) {
    if (max_size <= min_size)
      return min_amount;
    else if (size <= min_size)
      return min_amount;
    else if (size >= max_size)
      return max_amount;
    else
      return (scale(max_amount, size - min_size, max_size - min_size)
              + scale(min_amount, max_size - size, max_size - min_size));
  }
  else
    return H0;
}

void track_kern()
{
  int n = get_fontno();
  if (n >= 0) {
    int min_s, max_s;
    hunits min_a, max_a;
    if (has_arg()
        && get_number(&min_s, 'z')
        && get_hunits(&min_a, 'p')
        && get_number(&max_s, 'z')
        && get_hunits(&max_a, 'p')) {
      track_kerning_function tk(min_s, min_a, max_s, max_a);
      font_table[n]->set_track_kern(tk);
    }
    else {
      track_kerning_function tk;
      font_table[n]->set_track_kern(tk);
    }
  }
  skip_line();
}

void constant_space()
{
  int n = get_fontno();
  if (n >= 0) {
    int x, y;
    if (!has_arg() || !get_integer(&x))
      font_table[n]->set_constant_space(CONSTANT_SPACE_NONE);
    else {
      if (!has_arg() || !get_number(&y, 'z'))
        font_table[n]->set_constant_space(CONSTANT_SPACE_RELATIVE, x);
      else
        font_table[n]->set_constant_space(CONSTANT_SPACE_ABSOLUTE, 
                                          scale(y*x,
                                                units_per_inch,
                                                36*72*sizescale));
    }
  }
  skip_line();
}

void ligature()
{
  int lig;
  if (has_arg() && get_integer(&lig) && lig >= 0 && lig <= 2)
    global_ligature_mode = lig;
  else
    global_ligature_mode = 1;
  skip_line();
}

void kern_request()
{
  int k;
  if (has_arg() && get_integer(&k))
    global_kern_mode = k != 0;
  else
    global_kern_mode = 1;
  skip_line();
}

void set_soft_hyphen_char()
{
  soft_hyphen_char = get_optional_char();
  if (!soft_hyphen_char)
    soft_hyphen_char = get_charinfo(HYPHEN_SYMBOL);
  skip_line();
}

void init_output()
{
  if (suppress_output_flag)
    the_output = new suppress_output_file;
  else if (ascii_output_flag)
    the_output = new ascii_output_file;
  else
    the_output = new troff_output_file;
}

class next_available_font_position_reg : public reg {
public:
  const char *get_string();
};

const char *next_available_font_position_reg::get_string()
{
  return itoa(next_available_font_position());
}

class printing_reg : public reg {
public:
  const char *get_string();
};

const char *printing_reg::get_string()
{
  if (the_output)
    return the_output->is_printing() ? "1" : "0";
  else
    return "0";
}

void init_node_requests()
{
  init_request("fp", font_position);
  init_request("sty", style);
  init_request("cs", constant_space);
  init_request("bd", bold_font);
  init_request("uf", underline_font);
  init_request("lg", ligature);
  init_request("kern", kern_request);
  init_request("tkf", track_kern);
  init_request("special", special_request);
  init_request("fspecial", font_special_request);
  init_request("ftr", font_translate);
  init_request("shc", set_soft_hyphen_char);
  number_reg_dictionary.define(".fp", new next_available_font_position_reg);
  number_reg_dictionary.define(".kern",
                               new constant_int_reg(&global_kern_mode));
  number_reg_dictionary.define(".lg",
                               new constant_int_reg(&global_ligature_mode));
  number_reg_dictionary.define(".P", new printing_reg);
  soft_hyphen_char = get_charinfo(HYPHEN_SYMBOL);
}