/* This file is part of the GNU plotutils package.  Copyright (C) 1995,
   1996, 1997, 1998, 1999, 2000, 2005, 2008, Free Software Foundation, Inc.

   The GNU plotutils package is free software.  You may 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.

   The GNU plotutils package 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 the GNU plotutils package; see the file COPYING.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin St., Fifth Floor,
   Boston, MA 02110-1301, USA. */

/* _pl_g_controlify() converts a "label" (i.e. a character string), which may
   contain troff-like escape sequences, into a string of unsigned shorts.
   The possible troff-like escape sequences are listed in g_cntrlify.h.

   This conversion is to facilitate rendering.  _pl_g_controlify() is
   called by alabel(), and the converted label is rendered by
   _alabel_standard(), _alabel_stroke(), or _alabel_device(), depending on
   what sort of font is currently selected.  See g_alabel.c
   (_pl_g_controlify() is called by labelwidth() too).

   If the currently selected font is a font with ISO-Latin-1 encoding, the
   valid escape sequences include escape sequences for the non-ASCII
   ISO-Latin-1 characters.  Also allowed are such escape sequences as \f0,
   \f1, \f2, \f3, \f4, etc., which switch among the various fonts in the
   current typeface:

   	\f1	Switch to font #1, basic
	\f2	Switch to font #2, italic
	\f3	Switch to font #3, bold
	\f4	Switch to font #4, bold italic
	\f0	Switch to font #0, symbol (including Greek characters)
   
   \fP switches to the previously used font (there is a depth-1 stack,
   i.e. only one previous font is remembered, as in troff).

   All typefaces include at least two fonts: fonts #0 and #1.  Some may
   include more than the above five.  Each unsigned short in the converted
   string is really an annotated character: the low byte is the character,
   and the high byte is the font number.

   Besides font annotations, the controlified string may include control
   codes (unsigned shorts with particular bit patterns in their high
   bytes), which are produced by the escape sequences:

        \sp  start superscript
        \ep  end superscript

        \sb  start subscript
        \eb  end subscript

        \mk  mark location
        \rt  return to mark 
	     [useful e.g. for underlining, and filling square roots]

    There are also control codes for horizontal shifts.  \r1, \r2, \r4,
    \r6, \r8, \r^ will produce control codes that will shift right by 1 em,
    1/2 em, 1/4 em, 1/6 em, 1/8 em, 1/12 em, respectively.  \l1, \l2, \l4,
    \l6, \l8, \l^ are similar.

    The string of unsigned shorts, which is returned, is allocated with
    malloc and may be freed later. */

#include "sys-defines.h"
#include "extern.h"
#include "g_control.h"
#include "g_cntrlify.h"
#include "g_jis.h"

/* these two array lengths must agree with values in file g_her_glyph.c */
#define NUM_OCCIDENTAL_HERSHEY_GLYPHS 4400
#define NUM_ORIENTAL_HERSHEY_GLYPHS 5500

unsigned short *
_pl_g_controlify (R___(Plotter *_plotter) const unsigned char *src)
{     
  unsigned short *dest;
  unsigned char c, d;
  unsigned char esc[3];
  int j = 0;			/* index into destination string */
  int raw_fontnum, raw_symbol_fontnum;
  int previous_raw_fontnum;	/* implement depth-1 stack */
  unsigned short fontword, symbol_fontword;
  
  /* note: string length can grow by a factor of 6, because a single
     printable character can be mapped to a sequence of unsigned shorts, of
     length up to 6 (see comment below) */
  dest = (unsigned short *)_pl_xmalloc ((6 * strlen ((char *)src) + 1) * sizeof(unsigned short));
  
  /* Determine initial number of font, as index into low-level table in
     g_fontdb.c, and the initial value for the shifted `font word' which
     we'll OR with each character; also same, for associated symbol font.
     May be updated by \f0, \f1, etc. */
  switch (_plotter->drawstate->font_type)
    {
    case PL_F_POSTSCRIPT:
    default:
      raw_fontnum = _pl_g_ps_typeface_info[_plotter->drawstate->typeface_index].fonts[_plotter->drawstate->font_index];
      raw_symbol_fontnum = _pl_g_ps_typeface_info[_plotter->drawstate->typeface_index].fonts[0];
      break;
    case PL_F_PCL:
      raw_fontnum = _pl_g_pcl_typeface_info[_plotter->drawstate->typeface_index].fonts[_plotter->drawstate->font_index];
      raw_symbol_fontnum = _pl_g_pcl_typeface_info[_plotter->drawstate->typeface_index].fonts[0];
      break;
    case PL_F_STICK:
      raw_fontnum = _pl_g_stick_typeface_info[_plotter->drawstate->typeface_index].fonts[_plotter->drawstate->font_index];
      raw_symbol_fontnum = _pl_g_stick_typeface_info[_plotter->drawstate->typeface_index].fonts[0];
      break;
    case PL_F_HERSHEY:
      raw_fontnum = _pl_g_hershey_typeface_info[_plotter->drawstate->typeface_index].fonts[_plotter->drawstate->font_index];
      raw_symbol_fontnum = _pl_g_hershey_typeface_info[_plotter->drawstate->typeface_index].fonts[0];
      break;
    case PL_F_OTHER:
      /* no real font table in this case; by convention font #1 internally
         means the current device-specific font and #0 is an associated
         symbol font */
      raw_fontnum = 1;
      raw_symbol_fontnum = 0;
      break;
    }
  /* Of the following two words, `fontword' is updated whenever an escape
     sequence like \f0, \f1, \f2 etc. is seen, since raw_fontnum is itself
     updated.  But `symbol_fontword' is fixed */
  fontword = ((unsigned short)raw_fontnum) << FONT_SHIFT;
  symbol_fontword = ((unsigned short)raw_symbol_fontnum) << FONT_SHIFT;

  /* Implement depth-1 stack of fonts, for use by \fP macro */
  previous_raw_fontnum = raw_fontnum;

  while (*src != (unsigned char)'\0')
    {
      /* If EUC, check first for high bit and process two-byte characters
	 separately.  This approach is awkward (we duplicate a lot of code
	 here, which appears elsewhere below). */

      if ((raw_fontnum == PL_HERSHEY_EUC) 
	  && (*src & 0x80) && (*(src + 1) & 0x80))
	{
	  unsigned char jis_row = *src & ~(0x80);
	  unsigned char jis_col = *(src + 1) & ~(0x80);

	  if (GOOD_JIS_INDEX(jis_row, jis_col))
	    {
	      int jis_glyphindex = 256 * jis_row + jis_col;
	  
	      if (jis_glyphindex >= BEGINNING_OF_KANJI)
		/* in Kanji range, so check if we have it */
		{
#ifndef NO_KANJI
		  const struct kanjipair *kanji = _builtin_kanji_glyphs;
		  bool matched = false;
		  
		  while (kanji->jis != 0)
		    {
		      if (jis_glyphindex == kanji->jis)
			{
			  matched = true;
			  break;
			}
		      kanji++;
		    }
		  if (matched)
		    {
		      dest[j++] = RAW_ORIENTAL_HERSHEY_GLYPH | (kanji->nelson);
		      src += 2;
		      continue;	/* back to top of while loop */
		    }
		  else		/* a Kanji we don't have */
		    {
		      /* render as standard `undefined character' glyph */
		      dest[j++] = RAW_HERSHEY_GLYPH | UNDE;
		      src += 2;
		      continue;	/* back to top of while loop */
		    }
#endif /* not NO_KANJI */
		}
	      else
		/* not in Kanji range, so look for it in char table */
		{
		  const struct jis_entry *char_mapping = _builtin_jis_chars;
		  bool matched = false;
		  
		  while (char_mapping->jis != 0)
		    {
		      if (jis_glyphindex == char_mapping->jis)
			{
			  matched = true;
			  break;
			}
		      char_mapping++;
		    }
		  if (matched)
		    /* the entry in the character table maps the JIS
		       character to a character (in 0..255 range) in
		       one of the fonts in the master table in g_fontdb.c */
		    {
		      int fontnum = char_mapping->font;
		      unsigned short charnum = char_mapping->charnum;
		      
		      if (charnum & RAW_HERSHEY_GLYPH)
			/* a raw Hershey glyph, not in any font */
			dest[j++] = RAW_HERSHEY_GLYPH | charnum;
		      else
			/* a character in one of the fonts in g_fontdb.c */
			dest[j++] = (((unsigned short)fontnum) << FONT_SHIFT) | charnum;
		      src += 2;
		      continue; /* back to top of while loop */
		    }
		  else	/* a character we don't have */
		    {
		      /* render as standard `undefined character' glyph */
		      dest[j++] = RAW_HERSHEY_GLYPH | UNDE;
		      src += 2;
		      continue;	/* back to top of while loop */
		    }
		}
	    }
	  else
	    /* JIS index is OOB */
	    {
	      src += 2;
	      continue;		/* back to top of while loop */
	    }
	}

      /* if current font is Hershey, first try to match each ligature
         pattern (no ligatures supported in non-Hershey fonts) */
      if (_plotter->drawstate->font_type == PL_F_HERSHEY)
	{
	  int i;
	  bool matched = false;
	  
	  for (i = 0; i < NUM_LIGATURES; i++) 
	    if ((_ligature_tbl[i].font == raw_fontnum)
		&& (strncmp ((char *)src, _ligature_tbl[i].from, 
			     strlen (_ligature_tbl[i].from)) == 0))
	      {
		matched = true;
		break;
	      }
	  
	  if (matched)
	    {
	      dest[j++] = fontword | (unsigned short)_ligature_tbl[i].byte;
	      src += strlen (_ligature_tbl[i].from);
	      continue;		/* back to top of while loop */
	    }
	}

      c = *(src++);		/* no ligature, so get single new char */
      if (c != (unsigned char)'\\') /* ordinary char, may pass through */
	{
	  /* if current font is an ISO-Latin-1 Hershey font ... */
	  if (_plotter->drawstate->font_type == PL_F_HERSHEY
	      && _pl_g_hershey_font_info[raw_fontnum].iso8859_1)
	    {
	      int i;
	      bool matched = false;

	      /* check if this is a `raised' ISO-Latin-1 character */
	      for (i = 0; i < NUM_RAISED_CHARS; i++) 
		if (c == _raised_char_tbl[i].from)
		  {
		    matched = true;
		    break;
		  }
	      if (matched)	/* it's a raised character */
		{
		  /* map to string of unsigned shorts, length 3 or 6:
		     `begin superscript' control code, [`mark'
		     control code,] replacement char, [`return'
		     control code, underline,] `end superscript' */
		  dest[j++] = 
		    (unsigned short) (CONTROL_CODE | C_BEGIN_SUPERSCRIPT);
		  if (_raised_char_tbl[i].underscored) /* also underline */
		    {
		      dest[j++] = 
			(unsigned short) (CONTROL_CODE | C_PUSH_LOCATION);
		      dest[j++] = 
			fontword | (unsigned short)_raised_char_tbl[i].to;
		      dest[j++] = 
			(unsigned short) (CONTROL_CODE | C_POP_LOCATION);
		      /* select appropriate HersheySymbol font */
		      dest[j++] = 
			symbol_fontword | (unsigned short)VECTOR_SYMBOL_FONT_UNDERSCORE;
		    }
		  else	/* just print raised char, no underline */
		    dest[j++] = 
		      fontword | (unsigned short)_raised_char_tbl[i].to;
		  
		  dest[j++] = 
		    (unsigned short) (CONTROL_CODE | C_END_SUPERSCRIPT);
		  
		  continue; /* back to top of while loop */
		}

	      /* since current font is an ISO-Latin-1 Hershey font, also
                 check if this char should be deligatured */
	      for (i = 0; i < NUM_DELIGATURED_CHARS; i++) 
		if (c == _deligature_char_tbl[i].from)
		  {
		    matched = true;
		    break;
		  }
	      if (matched)
		{
		  if (_deligature_char_tbl[i].except_font != raw_fontnum)
		    {
		      dest[j++] = fontword 
			| (unsigned short)_deligature_char_tbl[i].to[0];
		      dest[j++] = fontword 
			| (unsigned short)_deligature_char_tbl[i].to[1];
		      continue;	/* back to top of while loop */
		    }
		}
	    }
	  
	  /* didn't do anything special, so just pass the character thru */
	  dest[j++] = fontword | (unsigned short)c; 
	  continue;		/* back to top of while loop */
	}
      else			/* character is a backslash */
	{
	  c = *(src++);		/* grab next character */
	  if (c == (unsigned char)'\0')	/* ASCII NUL ? */
	    {
	      dest[j++] = fontword | (unsigned short)'\\';
	      break;		/* string terminated with a backslash */
	    }
	  
 	  if (c == (unsigned char)'\\')
	    {
	      dest[j++] = fontword | (unsigned short)'\\';
	      dest[j++] = fontword | (unsigned short)'\\';
	      continue;		/* saw \\, leave as is */
	    }

	  d = *(src++);
 	  if (d == (unsigned char)'\0')
	    {
	      dest[j++] = fontword | (unsigned short)'\\';
	      dest[j++] = fontword | (unsigned short)c;
	      break;		/* string terminated with \c */
	    }

	  esc[0] = c;
	  esc[1] = d;
	  esc[2] = (unsigned char)'\0';	/* have an escape sequence */
	  
	  /* is this an escape seq. (e.g. \#H0001) for a raw Hershey glyph? */
	  if (_plotter->drawstate->font_type == PL_F_HERSHEY
	      && esc[0] == '#' && esc[1] == 'H'
	      && src[0] >= '0' && src[0] <= '9'
	      && src[1] >= '0' && src[1] <= '9'
	      && src[2] >= '0' && src[2] <= '9'
	      && src[3] >= '0' && src[3] <= '9')
	    {
	      int glyphindex;

	      glyphindex = (src[3] - '0') + 10 * (src[2] - '0')
		+ 100 * (src[1] - '0') + 1000 * (src[0] - '0');
	      if (glyphindex < NUM_OCCIDENTAL_HERSHEY_GLYPHS)
		{
		  dest[j++] = RAW_HERSHEY_GLYPH | glyphindex;
		  src += 4;
		  continue;	/* back to top of while loop */
		}
	    }

#ifndef NO_KANJI
	  /* is this an escape seq. (e.g. \#N0001) for a raw Japanese
             Hershey glyph (Kanji), as numbered in Nelson's dictionary? */
	  if (_plotter->drawstate->font_type == PL_F_HERSHEY
	      && esc[0] == '#' && esc[1] == 'N'
	      && src[0] >= '0' && src[0] <= '9'
	      && src[1] >= '0' && src[1] <= '9'
	      && src[2] >= '0' && src[2] <= '9'
	      && src[3] >= '0' && src[3] <= '9')
	    {
	      int glyphindex;

	      glyphindex = (src[3] - '0') + 10 * (src[2] - '0')
		+ 100 * (src[1] - '0') + 1000 * (src[0] - '0');
	      if (glyphindex < NUM_ORIENTAL_HERSHEY_GLYPHS)
		{
		  dest[j++] = RAW_ORIENTAL_HERSHEY_GLYPH | glyphindex;
		  src += 4;
		  continue;	/* back to top of while loop */
		}
	    }
#endif /* not NO_KANJI */

	  /* is this an escape seq. (e.g. \#J0001) for a raw Japanese
             Hershey glyph (JIS numbering, in hex)? */
	  if (_plotter->drawstate->font_type == PL_F_HERSHEY
	      && esc[0] == '#' && esc[1] == 'J'
	      && ((src[0] >= '0' && src[0] <= '9')
		  || (src[0] >= 'a' && src[0] <= 'f')
		  || (src[0] >= 'A' && src[0] <= 'F'))
	      && ((src[1] >= '0' && src[1] <= '9')
		  || (src[1] >= 'a' && src[1] <= 'f')
		  || (src[1] >= 'A' && src[1] <= 'F'))
	      && ((src[2] >= '0' && src[2] <= '9')
		  || (src[2] >= 'a' && src[2] <= 'f')
		  || (src[2] >= 'A' && src[2] <= 'F'))
	      && ((src[3] >= '0' && src[3] <= '9')
		  || (src[3] >= 'a' && src[3] <= 'f')
		  || (src[3] >= 'A' && src[3] <= 'F')))
	    {
	      int jis_glyphindex;
	      int i, hexnum[4];
	      int jis_row, jis_col;
	      
	      for (i = 0; i < 4; i++)
		if (src[i] >= 'a' && src[i] <= 'f')
		  hexnum[i] = 10 + src[i] - 'a';
		else if (src[i] >= 'A' && src[i] <= 'F')
		  hexnum[i] = 10 + src[i] - 'A';
		else /* a decimal digit */
		  hexnum[i] = src[i] - '0';

	      jis_glyphindex = (hexnum[3] + 16 * hexnum[2]
				+ 256 * hexnum[1] + 4096 * hexnum[0]);
	      jis_row = hexnum[1] + 16 * hexnum[0];
	      jis_col = hexnum[3] + 16 * hexnum[2];

	      if (GOOD_JIS_INDEX(jis_row, jis_col))
		{
		  if (jis_glyphindex >= BEGINNING_OF_KANJI)
		    /* in Kanji range, so check if we have it */
		    {
#ifndef NO_KANJI
		      const struct kanjipair *kanji = _builtin_kanji_glyphs;
		      bool matched = false;
		      
		      while (kanji->jis != 0)
			{
			  if (jis_glyphindex == kanji->jis)
			    {
			      matched = true;
			      break;
			    }
			  kanji++;
			}
		      if (matched)
			{
			  dest[j++] = RAW_ORIENTAL_HERSHEY_GLYPH | (kanji->nelson);
			  src += 4;
			  continue;	/* back to top of while loop */
			}
		      else		/* a Kanji we don't have */
			{
			  /* render as standard `undefined character' glyph */
			  dest[j++] = RAW_HERSHEY_GLYPH | UNDE;
			  src += 4;
			  continue;	/* back to top of while loop */
			}
#endif /* not NO_KANJI */
		    }
		  else
		    /* not in Kanji range, so look for it in char table */
		    {
		      const struct jis_entry *char_mapping = _builtin_jis_chars;
		      bool matched = false;
		      
		      while (char_mapping->jis != 0)
			{
			  if (jis_glyphindex == char_mapping->jis)
			    {
			      matched = true;
			      break;
			    }
			  char_mapping++;
			}
		      if (matched)
			/* the entry in the character table maps the JIS
			   character to a character (in 0..255 range) in
			   one of the fonts in the master table in g_fontdb.c*/
			{
			  int fontnum = char_mapping->font;
			  unsigned short charnum = char_mapping->charnum;
			  
			  if (charnum & RAW_HERSHEY_GLYPH)
			    /* a raw Hershey glyph, not in any font */
			    dest[j++] = RAW_HERSHEY_GLYPH | charnum;
			  else
			    /* a character in one of the fonts in g_fontdb.c */
			    dest[j++] = (((unsigned short)fontnum) << FONT_SHIFT) | charnum;
			  src += 4;
			  continue; /* back to top of while loop */
			}
		      else	/* a character we don't have */
			{
			  /* render as standard `undefined character' glyph */
			  dest[j++] = RAW_HERSHEY_GLYPH | UNDE;
			  src += 4;
			  continue;	/* back to top of while loop */
			}
		    }
		}
	    }

	  {
	    int i;
	    bool matched = false;

	    /* is this an escape seq. for a control code? */
	    for (i = 0; i < NUM_CONTROLS; i++) 
	      if (strcmp ((char *)esc, _control_tbl[i]) == 0)
		{
		  matched = true;
		  break;
		}
	    if (matched)		/* it's a control code */
	      {
		dest[j++] = CONTROL_CODE | i;
		continue;	/* back to top of while loop */
	      }
	  }

	  /* if current font is an ISO-Latin-1 Hershey font, is this an
	     escape sequence for an 8-bit (non-ASCII) char, which due to
	     nonexistence should be deligatured? */
	  if (_plotter->drawstate->font_type == PL_F_HERSHEY
	      && _pl_g_hershey_font_info[raw_fontnum].iso8859_1)
	    {
	      int i;
	      bool matched = false;
	     
	      for (i = 0; i < NUM_DELIGATURED_ESCAPES; i++)
		if (strcmp ((char *)esc, _deligature_escape_tbl[i].from) == 0)
		  {
		    matched = true;
		    break;
		  }
	      if (matched)
		{
		  if (_deligature_escape_tbl[i].except_font != raw_fontnum)
		    {
		      dest[j++] = fontword 
			| (unsigned short)_deligature_escape_tbl[i].to[0];
		      dest[j++] = fontword 
			| (unsigned short)_deligature_escape_tbl[i].to[1];

		      continue;	/* back to top of while loop */
		    }
		}
	    }

	  /* if the current font is an ISO-Latin-1 font (no matter whether
             font is a a Hershey font, a PS or PCL/Stick font, or a
             device-specific font for which we have no table entry), is
             this an escape seq. for an 8-bit (non-ASCII) ISO8859-1 char?  */
	  if ((_plotter->drawstate->font_type == PL_F_POSTSCRIPT
	       && _pl_g_ps_font_info[raw_fontnum].iso8859_1)
	      || (_plotter->drawstate->font_type == PL_F_HERSHEY
		  && _pl_g_hershey_font_info[raw_fontnum].iso8859_1)
	      || (_plotter->drawstate->font_type == PL_F_PCL
		  && _pl_g_pcl_font_info[raw_fontnum].iso8859_1)
	      || (_plotter->drawstate->font_type == PL_F_STICK
		  && _pl_g_stick_font_info[raw_fontnum].iso8859_1)
	      || (_plotter->drawstate->font_type == PL_F_OTHER
		  && _plotter->drawstate->font_is_iso8859_1
		  && raw_fontnum == 1))
	    {
	      int i;
	      bool matched = false;

	      for (i = 0; i < NUM_ISO_ESCAPES; i++) 
		if (strcmp ((char *)esc, _iso_escape_tbl[i].string) == 0)
		  {
		    matched = true;
		    break;
		  }
	      if (matched)	/* it's an 8-bit ISO8859-1 character */
		{
		  /* certain such characters are drawn in the Hershey fonts
                     as superscripts */
		  if (_plotter->drawstate->font_type == PL_F_HERSHEY)
		    {
		      int k;
		      bool matched2 = false;
		      
		      /* check if this is a `raised' ISO-Latin-1 character */
		      for (k = 0; k < NUM_RAISED_CHARS; k++) 
			if (_iso_escape_tbl[i].byte == _raised_char_tbl[k].from)
			  {
			    matched2 = true;
			    break;
			  }
		      if (matched2)	/* it's a raised character */
			{
			  /* map to string of unsigned shorts, length 3 or 6:
			     `begin superscript' control code, [`mark'
			     control code,] replacement char, [`return'
			     control code, underline,] `end superscript' */
			  dest[j++] = 
			    (unsigned short) (CONTROL_CODE | C_BEGIN_SUPERSCRIPT);
			  if (_raised_char_tbl[k].underscored) /* also underline */
			    {
			      dest[j++] = 
				(unsigned short) (CONTROL_CODE | C_PUSH_LOCATION);
			      dest[j++] = 
				fontword | (unsigned short)_raised_char_tbl[k].to;
			      dest[j++] = 
				(unsigned short) (CONTROL_CODE | C_POP_LOCATION);
			      /* select appropriate HersheySymbol font */
			      dest[j++] = 
				symbol_fontword | (unsigned short)VECTOR_SYMBOL_FONT_UNDERSCORE;
			    }
			  else	/* just print raised char, no underline */
			    {
			      dest[j++] = 
				fontword | (unsigned short)_raised_char_tbl[k].to;
			    }

			  dest[j++] = 
			    (unsigned short) (CONTROL_CODE | C_END_SUPERSCRIPT);

			  continue; /* back to top of while loop */
			}
		    }

		  /* won't draw this char as a superscript; just pass thru */
		  dest[j++] = fontword | (unsigned short)(_iso_escape_tbl[i].byte);
		  continue;	/* back to top of while loop */
		}
	    }

	  /* is this an escape seq. for a `special' (non-ISO, non-Symbol)
	     Hershey glyph?  Such glyphs include astronomical signs, and
	     `final s'. */
	  if (_plotter->drawstate->font_type == PL_F_HERSHEY)
	    {
	      int i;
	      bool matched = false;

	      for (i = 0; i < NUM_SPECIAL_ESCAPES; i++) 
		if (strcmp ((char *)esc, _special_escape_tbl[i].string) == 0)
		  {
		    matched = true;
		    break;
		  }
	      if (matched)	/* it's a special character */
		{
		  /* "\s-" is special; yields character in current font */
		  if (_special_escape_tbl[i].byte == FINAL_LOWERCASE_S)
		  dest[j++] = 
		    fontword | (unsigned short)(_special_escape_tbl[i].byte);
		  else
		  /* we select symbol font of typeface, in which we've
		     stored all other special characters */
		    dest[j++] = symbol_fontword | (unsigned short)(_special_escape_tbl[i].byte);
		  continue;	/* back to top of while loop */
		}
	    }

	  {
	    int i;
	    bool matched = false;
	    
	    /* Irrespective of font type, is this an escape seq. for a char
	       in the font's corresponding symbol font? */
	    for (i = 0; i < NUM_SYMBOL_ESCAPES; i++) 
	      if (strcmp (_symbol_escape_tbl[i].string, "NO_ABBREV") != 0
		  && strcmp ((char *)esc, _symbol_escape_tbl[i].string) == 0)
		{
		  matched = true;
		  break;
		}
	    if (matched)	/* it's a character in the symbol font */
	      {
		/* select symbol font by OR'ing in the symbol fontword */
		dest[j++] = symbol_fontword | (unsigned short)(_symbol_escape_tbl[i].byte);
		continue;	/* back to top of while loop */
	      }
	  }

	  /* Gross kludge.  In the non-Hershey fonts we handle the "\rn"
	     control sequence in a painful way.  For a PS font we map it
	     into (1) a left shift, (2) the `radicalex' character in the PS
	     Symbol font, and (3) a right shift.  Shift distances are taken
	     from the bbox of the radicalex char, and are slightly larger
	     than 0.5 em.  For a PCL font it's similar, but the shifts are
	     much smaller.  The reason it's different for PCL is that the
	     PCL radicalex character is different from the PS radicalex
	     character: the overbar is not displaced.  Possibly someone at
	     HP made a mistake while reimplementing the Adobe Symbol font
	     for PCL 5?

	     We don't implement \rn for Stick fonts, because they have
	     no associated symbol font. */
	  if (strcmp ((char *)esc, "rn") == 0)
	    {
	      if (_plotter->drawstate->font_type == PL_F_POSTSCRIPT
		  || _plotter->drawstate->font_type == PL_F_PCL)
		{
		  dest[j++] 
		    = (unsigned short)(CONTROL_CODE | C_LEFT_RADICAL_SHIFT);
		  /* take `radicalex' glyph from PS symbol font */
		  dest[j++] 
		    = symbol_fontword | (unsigned short)RADICALEX; 
		  dest[j++] 
		    = (unsigned short)(CONTROL_CODE | C_RIGHT_RADICAL_SHIFT);

		  continue;	/* back to top of while loop */
		}
	    }

	  /* Attempt to parse as a font-change command, i.e. as one of the
	     macros \f0, \f1, \f2, etc., or \fP.  \fR, \fI, \fB are the
	     same as \f1, \f2, \f3 for troff compatibility. */

	  if (esc[0] == 'f' && ((esc[1] >= '0' && esc[1] <= '9')
				|| esc[1] == 'P' || esc[1] == 'R'
				|| esc[1] == 'I' || esc[1] == 'B'))
	    {
	      /* If a user-specified, device-specific font [e.g. an X font,
		 for which we have no internal table listing the other
		 fonts in its family] is being used, we can't really do
		 font switching, except via \f0, \f1.  These switch to the
		 X symbol font and the current user-specified font,
		 respectively.  (\fP is also supported.) */
	      if (_plotter->drawstate->font_type == PL_F_OTHER
		  && ((esc[1] >= '2' && esc[1] <= '9')
		      || esc[1] == 'I' || esc[1] == 'B'))
		esc[1] = '1'; /* treat as \f1 */
	      
	      /* troff compatibility */
	      if (esc[1] == 'R')
		esc[1] = '1';
	      else if (esc[1] == 'I')
		esc[1] = '2';
	      else if (esc[1] == 'B')
		esc[1] = '3';

	      if (esc[1] == 'P') /* \fP seen, so go back to previous font */
		raw_fontnum = previous_raw_fontnum;
	      else		/* font specified as index into typeface */
		{
		  int new_font_index = esc[1] - '0';

		  /* switch to specified font (OOB tests here now obsolete?) */
		  previous_raw_fontnum = raw_fontnum;
		  switch (_plotter->drawstate->font_type)
		    {
		    case PL_F_HERSHEY:
		      if ((new_font_index >= _pl_g_hershey_typeface_info[_plotter->drawstate->typeface_index].numfonts)
			  || new_font_index < 0)
			new_font_index = 1; /* OOB -> use default font */
		      raw_fontnum = _pl_g_hershey_typeface_info[_plotter->drawstate->typeface_index].fonts[new_font_index];
		      break;
		    case PL_F_PCL:
		      if ((new_font_index >= _pl_g_pcl_typeface_info[_plotter->drawstate->typeface_index].numfonts)
			  || new_font_index < 0)
			new_font_index = 1; /* OOB -> use default font */
		      raw_fontnum = _pl_g_pcl_typeface_info[_plotter->drawstate->typeface_index].fonts[new_font_index];
		      break;
		    case PL_F_STICK:
		      if ((new_font_index >= _pl_g_stick_typeface_info[_plotter->drawstate->typeface_index].numfonts)
			  || new_font_index < 0)
			new_font_index = 1; /* OOB -> use default font */
		      raw_fontnum = _pl_g_stick_typeface_info[_plotter->drawstate->typeface_index].fonts[new_font_index];
		      break;
		    case PL_F_POSTSCRIPT:
		    default:
		      if ((new_font_index >= _pl_g_ps_typeface_info[_plotter->drawstate->typeface_index].numfonts)
			  || new_font_index < 0)
			new_font_index = 1; /* OOB -> use default font */
		      raw_fontnum = _pl_g_ps_typeface_info[_plotter->drawstate->typeface_index].fonts[new_font_index];
		      break;
		    case PL_F_OTHER:
		      if (new_font_index != 0 && new_font_index != 1)
			new_font_index = 1; /* OOB -> use default font */
		      raw_fontnum = new_font_index;
		      break;
		    }
		}

	      fontword = ((unsigned short)raw_fontnum) << FONT_SHIFT;

	      continue;		/* back to top of while loop */
	    }
	  
	  /* couldn't match; unknown escape seq., so pass through unchanged */
	  dest[j++] = fontword | (unsigned short)'\\';
	  dest[j++] = fontword | (unsigned short)c;
	  dest[j++] = fontword | (unsigned short)d;
	}
    }

  dest[j] = (unsigned short)'\0';   /* terminate string */

  return dest;
}

int 
_codestring_len (const unsigned short *codestring)
{
  int i = 0;

  while (*codestring)
    {
      i++;
      codestring++;
    }
  
  return i;
}