/* $Id: dmp.c,v 1.14 2005/08/24 10:54:02 taco Exp $
   Public domain.  */

/* dmp x
 *
 * This program reads device-independent troff output files,
 * and converts them into a symbolic form understood by MetaPost.  Some
 * of the code was borrowed from DVItoMP.  It understands all the D? graphics
 * functions that dpost does but it ignores `x X' device control functions
 * such as `x X SetColor:...', `x X BeginPath:', and `x X DrawPath:...'.
 *
 * The output file is a sequence of MetaPost picture expressions, one for every
 * page in the input file.  It makes no difference where the input file comes
 * from, but it is intended to process the result of running eqn and troff on
 * the output of MPtoTR.  Such a file contains one page for every btex...etex
 * block in the original input.  This program then creates a corresponding
 * sequence of MetaPost picture expressions for use as an auxiliary input file.
 * Since MetPost expects such files to have the extension .mpx, the output
 * is sometimes called an `mpx' file.
 */

/*  The |banner| string defined here should be changed whenever this program
 *  gets modified.
 */

char *banner = "% Written by DMP, Version 0.992";	/* first line of output */
char *term_banner = "This is DMP, Version 0.992";

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>

#include "dmp.h"

#ifndef NULL
#define NULL ((char*) 0)
#endif

#ifndef PI
#define PI  3.14159265358979323846
#endif

#define FCOUNT	100		/* maximum number of fonts */
#define SHIFTS	100		/* maximum number of characters with special shifts */
#define line_length 79		/* maximum output line length (must be at least 60) */
#define Hprime	307		/* much bigger than max(chars/font,fonts/job) */
#define MAXCHARS 256		/* character codes fall in the range 0..MAXCHARS-1 */
#define LLENGTH 1024		/* one more than maximum line length for troff output */

#define is_specchar(c)	(!gflag && (c)<=2)	/* does charcode c identify a special char? */
#define LWscale	0.03		/* line width for graphics as a fraction of pointsize */
#define YCORR 12.0		/* V coordinate of reference point in (big) points */

char strpool[POOLMAX];		/* text for font names and char names */
int poolsize = 0;		/* chars used so far in strpool */

char *texname[FCOUNT];		/* TeX names (null-terminated strings) */
int font_num[FCOUNT];		/* external font numbers */
float font_design_size[FCOUNT];	/* design size in TeX points */
struct hcell *charcodes[FCOUNT];	/* hash tables for translating char names */
int next_specfnt[FCOUNT];	/* used to link special fonts together */
float charwd[FCOUNT][MAXCHARS];	/* width/ptsize indexed [font num][char code] */
int nfonts;			/* no. of internal font nums (texname indices) */
int shiftchar[SHIFTS];		/* charcode of character to shift, else -1 */
float shifth[SHIFTS], shiftv[SHIFTS];	/* shift vals/fontsize (y is upward) */
int shiftptr = 0;		/* number of entries in shift tables */
int shiftbase[FCOUNT];		/* initial index into shifth,shiftv,shiftchar */
int specfnt = FCOUNT;		/* int. num. of first special font (or FCOUNT) */
int *specf_tail = &specfnt;	/* tail of specfnt list (*specf_tail==FCOUNT) */
FILE *trf;			/* the input file (troff output) */
FILE *mpxf;			/* the output file */
struct hcell *trfonts;		/* hash tab for internal nums of troff fonts */
float unit = 0.0;		/* (big) points per troff unit (0 when unset) */
int h, v;			/* current position in tr. units (v downward) */
float cursize;			/* current type size in (big) points */
int curfont;			/* internal number for current font */
float Xslant;			/* degrees additional slant for all fonts */
float Xheight;			/* yscale fonts to this height if nonzero */
char *dbname = "trfonts.map";	/* file for table of troff & TFM font names */
char *adjname = "trchars.adj";	/* file for character shift amounts */
int lnno = 0;			/* line num. in troff output file (our input) */
float sizescale;		/* groff font size scaling factor */
int gflag = 0;			/* non-zero if using groff fonts */

void
quit(char *msg1, char *msg2, char *msg3)
{
    fprintf(stderr, "DMP abort at troff output line %d:\n%s%s%s\n",
	    lnno, msg1, msg2, msg3);
    exit(1);
}

void
warn(char *msg1, char *msg2, char *msg3)
{
    fprintf(stderr, "DMP warning at troff output line %d:\n%s%s%s\n",
	    lnno, msg1, msg2, msg3);
}

void
add_to_pool(char c)
{
    if (poolsize == POOLMAX) {
	fprintf(stderr, "%s", strpool);
	quit("Need to increase POOLMAX", "", "");
    } else
	strpool[poolsize++] = c;
}




/**************************************************************
			Hash tables
***************************************************************/

typedef struct hcell {
    char *lab;
    int datum;
} Hcell;

#define new_htab   (Hcell*) calloc((unsigned)Hprime, (unsigned)sizeof(Hcell))


int
hash(char *s)
{
    register int r;
    for (r = 0; *s != 0; s++) {
	/* GROFF - in font metrics file the character name may be 8bit
	   groff_font(5): Groff supports eight bit characters;
	   groff_out(5): Note that single characters can have the
	   eighth  bit  set, as can the names of fonts and special
	   characters.
	 */
	r = (r << 1) + *(unsigned char *) s;
	while (r >= Hprime)
	    r -= Hprime;
    }
    return r;
}


/* Find or insert the given string in the hash table and return the address
   of the datum.
*/
Hcell *failure;			/* null unless last hfind failed (used below) */

int *
hfind(char *s, Hcell * htab)
{
    register Hcell *p;
    register int cnt = Hprime;
    failure = (Hcell *) 0;
    p = &htab[hash(s)];
    do {
	if (p->lab == NULL) {
	    failure = p;
	    if (s < &strpool[0] || s >= &strpool[POOLMAX]) {
		p->lab = &strpool[poolsize];
		do
		    add_to_pool(*s);
		while (*s++ != '\0');
	    } else
		p->lab = s;
	    return &p->datum;
	}
	if (strcmp(s, p->lab) == 0)
	    return &p->datum;
	if (p == htab)
	    p = &htab[Hprime - 1];
	else
	    p--;
    } while (--cnt >= 0);
    quit("Need to increase Hprime", "", "");
    return (int *) 0;		/* keep lint happy */
}


/* If the last hfind() failed, undo the insertion and return zero (FALSE).
*/
int
hfound(void)
{
    if (failure == (Hcell *) 0)
	return 1;
    failure->lab = NULL;
    return 0;
}



/**************************************************************
			Scanning Numbers
***************************************************************/

/* The standard functions atoi(), atof(), and sscanf() provide ways of reading
   numbers from strings but they give no indication of how much of the string
   is consumed.  These homemade versions don't parse scientific notation.
*/
char *arg_tail;			/* char after the number just gotten; NULL on failure */


int
get_int(char *s)
{
    register int i, d, neg;
    if (s == NULL)
	goto bad;
    for (neg = 0;; s++)
	if (*s == '-')
	    neg = !neg;
	else if (*s != ' ' && *s != '\t')
	    break;
    if (i = *s - '0', 0 > i || i > 9)
	goto bad;
    while (d = *++s - '0', 0 <= d && d <= 9)
	i = 10 * i + d;
    arg_tail = s;
    return neg ? -i : i;
  bad:arg_tail = NULL;
    return 0;
}

/* GROFF font description files use octal character codes
   groff_font(5): The code can be any integer.  If it starts with
       a 0 it will be interpreted as octal; if it starts with  0x
       or 0X it will be intepreted as hexadecimal.
*/
int
get_int_map(char *s)
{
    register int i;
    if (s == NULL)
	goto bad;
    i = strtol(s, &arg_tail, 0);
    if (s == arg_tail)
	goto bad;
    return i;
  bad:arg_tail = NULL;
    return 0;
}

/* Troff output files contain few if any non-integers, but this program is
   prepared to read floats whenever they seem reasonable; i.e., when the
   number is not being used for character positioning.  (For non-PostScript
   applications h and v are usually in pixels and should be integers.)
*/
float
get_float(char *s)
{
    register int d, neg, digits;
    register float x, y;

    digits = 0;
    if (s != NULL) {
	for (neg = 0;; s++)
	    if (*s == '-')
		neg = !neg;
	    else if (*s != ' ' && *s != '\t')
		break;
	x = 0.0;
	while (d = *s - '0', 0 <= d && d <= 9) {
	    x = 10.0 * x + d;
	    digits++;
	    s++;
	}
	if (*s == '.') {
	    y = 1.0;
	    while (d = *++s - '0', 0 <= d && d <= 9) {
		y /= 10.0;
		x += y * d;
		digits++;
	    }
	}
    }
    if (digits == 0) {
	arg_tail = NULL;
	return 0.0;
    }
    arg_tail = s;
    return neg ? -x : x;
}

/* GROFF font description files have metrics field
   of comma-separated integers. Traditional troff
   have a float in this position. The value is not
   used anyway - thus just skip the value,
   eat all non-space chars.
*/
float
get_float_map(char *s)
{
    if (s != NULL) {
	while (isspace(*s))
	    s++;
	while (!isspace(*s) && *s)
	    s++;
    }
    arg_tail = s;
    return 0;
}

/**************************************************************
		Reading Initialization Files
***************************************************************/

/* Read the database file, reserve internal font numbers and set
   the texname[] entries.  Each line in the database file contains
   <troff-name>\t,PostScript-name>\t<TeX-name>
   or just <troff-name>\t,PostScript-name> if the TeX name matches the
   PostScript name. ("\t" means one or more tabs.)
*/

void
read_fmap(char *dbase)
{
    FILE *fin;
    int c;			/* last character read */
    char *nam;			/* a font name being read */

    nfonts = 0;
    fin = fsearch(dbase, "", DB_TYPE);
    trfonts = new_htab;
    while ((c = getc(fin)) != EOF) {
	if (nfonts == FCOUNT)
	    quit("Need to increase FCOUNT", "", "");
	nam = &strpool[poolsize];
	for (; c != '\t'; c = getc(fin)) {
	    if (c == EOF)
		break;
	    add_to_pool(c);
	}
	add_to_pool(0);
	*hfind(nam, trfonts) = nfonts;
	texname[nfonts] = &strpool[poolsize];
	do {
	    poolsize = texname[nfonts] - strpool;
	    do
		c = getc(fin);
	    while (c == '\t');
	    for (; c != '\t' && c != '\n'; c = getc(fin)) {
		if (c == EOF)
		    break;
		add_to_pool(c);
	    }
	    add_to_pool(0);
	} while (c == '\t');
	font_num[nfonts] = -1;	/* indicate font is not mounted */
	nfonts++;
    }
    fclose(fin);
}


/* Some characters need their coordinates shifted in order to agree with
   troff's view of the world.  Logically, this information belongs in the
   font description files but it actually resides in a PostScript prolog
   that the troff output processor dpost reads.  Since that file is in
   PostScript and subject to change, we read the same information from
   a small auxiliary file that gives shift amounts relative to the font
   size with y upward.
*/
/* GROFF NOTE:
   The PostScript prologue in GNU groff's font directory does not
   contain any character shift information, so the following function
   becomes redundant.  Simply keeping an empty "trchars.adj" file
   around will do fine without requiring any changes to this program.
*/
void
read_char_adj(char *adjfile)
{
    FILE *fin;
    char buf[200];
    int i;

    fin = fsearch(adjfile, "", DB_TYPE);
    for (i = 0; i < nfonts; i++)
	shiftbase[i] = 0;
    while (fgets(buf, 200, fin) != NULL) {
	if (shiftptr == SHIFTS - 1)
	    quit("Need to increase SHIFTS", "", "");
	if (buf[0] != ' ' && buf[0] != '\t') {
	    for (i = 0; buf[i] != '\0'; i++)
		if (buf[i] == '\n')
		    buf[i] = '\0';
	    shiftchar[shiftptr++] = -1;
	    shiftbase[*hfind(buf, trfonts)] = shiftptr;
	    if (!hfound())
		quit(adjfile, " refers to unknown font ", buf);
	} else {
	    shiftchar[shiftptr] = get_int(buf);
	    shifth[shiftptr] = get_float(arg_tail);
	    shiftv[shiftptr] = -get_float(arg_tail);
	    if (arg_tail == NULL)
		quit("Bad shift entry : \"", buf, "\"");
	    shiftptr++;
	}
    }
    shiftchar[shiftptr++] = -1;
    fclose(fin);
}

/* Read the DESC file of the troff device to gather information
   about sizescale and whether running under groff.
*/
void
read_desc(void)
{
    /* Ignore all commands not specially handled. This relieves
       of collecting commands without arguments here and also
       makes the program more robust in case of future DESC
       extensions.
     */
    const char *const k1[] = {
	"res", "hor", "vert", "unitwidth", "paperwidth",
	"paperlength", "biggestfont", "spare2", "encoding",
	NULL
    };
    const char *const g1[] = {
	"family", "paperheight", "postpro", "prepro",
	"print", "image_generator", "broken",
	NULL
    };
    char cmd[200];
    FILE *fp;
    int i, n;

    fp = fsearch("DESC", "", TRFONTS_TYPE);
    while (fscanf(fp, "%199s", cmd) != EOF) {
	if (*cmd == '#') {
	    while ((i = getc(fp)) != EOF && i != '\n');
	    continue;
	}
	if (strcmp(cmd, "fonts") == 0) {
	    if (fscanf(fp, "%d", &n) != 1)
		return;
	    for (i = 0; i < n; i++)
		if (fscanf(fp, "%*s") == EOF)
		    return;
	} else if (strcmp(cmd, "sizes") == 0) {
	    while (fscanf(fp, "%d", &n) == 1 && n != 0);
	} else if (strcmp(cmd, "styles") == 0 ||
		   strcmp(cmd, "papersize") == 0) {
	    gflag++;
	    while ((i = getc(fp)) != EOF && i != '\n');
	} else if (strcmp(cmd, "sizescale") == 0) {
	    if (fscanf(fp, "%d", &n) == 1)
		sizescale = n;
	    gflag++;
	} else if (strcmp(cmd, "charset") == 0) {
	    return;
	} else {
	    for (i = 0; k1[i]; i++)
		if (strcmp(cmd, k1[i]) == 0) {
		    if (fscanf(fp, "%*s") == EOF)
			return;
		    break;
		}
	    if (k1[i] == 0)
		for (i = 0; g1[i]; i++)
		    if (strcmp(cmd, g1[i]) == 0) {
			if (fscanf(fp, "%*s") == EOF)
			    return;
			gflag = 1;
			break;
		    }
	}
    }
}


/**************************************************************
			Reading Font Files
***************************************************************/


/* Read the TFM file for the font with internal number f, updating the
   data structures appropriately.  We get the character widths out of the
   tfm file instead of the troff font description file because they don't
   because the latter source reflects alterations made only by dpost (the
   troff output driver that is bypassed when using MetaPost).
*/
void
read_tfm(int f)
{
    FILE *tf;
    long a = 0;
    int sizes[5];		/* file & header lengths, bc, ec, words in wd table */
    long wd[256];		/* the width table (font size relative, scaled 2^20) */
    int i, j;
    long wtmp;			/* needed to a floating exception on certain machines */

    tf = fsearch(texname[f], ".tfm", TEXFONTS_TYPE);
    for (i = 0; i < 5; i++) {
	sizes[i] = getc(tf);
	sizes[i] = (sizes[i] << 8) | (getc(tf) & 0377);
    }
    if (sizes[1] < 2 || sizes[2] < 0 || sizes[3] < sizes[2] - 1
	|| sizes[3] > 255
	|| sizes[0] < sizes[1] + sizes[3] - sizes[2] + sizes[4] + 7)
	quit("Bad tfm file: ", texname[f], ".tfm");
    for (i = 2 * 5; i < 28; i++)
	(void) getc(tf);
    for (i = 0; i < 4; i++)
	a = (a << 8) | (long) (getc(tf) & 0377);
    font_design_size[f] = ((float) a) / 1048576.0;
    fseek(tf, (long) (28 + 4 * (sizes[1] + sizes[3] - sizes[2])), 0);
    for (i = 0; i < sizes[4]; i++) {
	wd[i] = 0L;
	for (j = 0; j < 4; j++)
	    wd[i] = (wd[i] << 8) | (long) (getc(tf) & 0377);
    }
    fseek(tf, (long) (24 + 4 * sizes[1]), 0);
    for (i = sizes[2]; i <= sizes[3]; i++) {
	wtmp = wd[getc(tf) & 0377];
	charwd[f][i] = ((double) wtmp) / 1048576.0 / unit;
	for (j = 3; --j >= 0;)
	    (void) getc(tf);
    }
    fclose(tf);
}


/* Given one line from the character description file for the font with
   internal number f, save the appropriate data in the charcodes[f] table.
   A return value of zero indicates a syntax error.
*/
/* GROFF NOTE:
   GNU groff uses an extended font description file format documented
   in groff_font(5).  In order to allow parsing of groff's font files,
   this function needs to be rewritten as follows:

   1. The `metrics' field parsed by "get_float(lin);" may include
      a comma-separated list of up to six decimal integers rather
      than just a single floating-point number.

   2. The `charcode' field parsed by "lastcode = get_int(arg_tail);"
      may be given either in decimal, octal, or hexadecimal format.
*/
int
scan_desc_line(int f, char *lin)
{
    static int lastcode;
    char *s;

    s = &strpool[poolsize];
    while (*lin != ' ' && *lin != '\t' && *lin != '\0')
	add_to_pool(*lin++);
    add_to_pool('\0');
    while (*lin == ' ' || *lin == '\t')
	lin++;
    if (*lin == '"') {
	if (lastcode < MAXCHARS)
	    *hfind(s, charcodes[f]) = lastcode;
    } else {
	(void) get_float_map(lin);
	(void) get_int(arg_tail);
	lastcode = get_int_map(arg_tail);
	if (arg_tail == NULL)
	    return 0;
	if (lastcode < MAXCHARS)
	    *hfind(s, charcodes[f]) = lastcode;
    }
    return 1;
}

/* Read the font description file for the font with the given troff name
   and update the data structures.  The result is the internal font number.
*/
int
read_fontdesc(char *nam)
{				/* troff name */
    char buf[200];
    FILE *fin;			/* input file */
    int f;			/* internal font number */

    if (unit == 0.0)
	quit("Resolution is not set soon enough", "", "");
    f = *hfind(nam, trfonts);
    if (!hfound())
	quit("Font was not in map file", "", "");
    fin = fsearch(nam, "", TRFONTS_TYPE);
    for (;;) {
	if (fgets(buf, 200, fin) == NULL)
	    quit("Description file for ", nam, " ends unexpectedly");
	if (strncmp(buf, "special", 7) == 0) {
	    *specf_tail = f;
	    next_specfnt[f] = FCOUNT;
	    specf_tail = &next_specfnt[f];
	} else if (strncmp(buf, "charset", 7) == 0)
	    break;
    }
    charcodes[f] = new_htab;
    while (fgets(buf, 200, fin) != NULL)
	if (scan_desc_line(f, buf) == 0)
	    quit(nam, " has a bad line in its description file: ", buf);
    fclose(fin);
    return f;
}



/**************************************************************
		Low Level Output Routines
***************************************************************/

/* One of the basic output operations is to write a \MP\ string expression for
   a sequence of characters to be typeset.  The main difficulties are that such
   strings can contain arbitrary eight-bit bytes and there is no fixed limit on
   the length of the string that needs to be produced.  In extreme cases this
   can lead to expressions such as
	char7&char15\&char31&"?FWayzz"
	&"zzaF"&char15&char3&char31
	&"Nxzzzzzzzwvtsqo"

   A global variable state keeps track of the output process.
   When state=normal we have begun a quoted string and the next character
   should be a printable character or a closing quote.  When state=special
   the last thing printed was a `char' construction or a closing quote
   and an ampersand should come next.  The starting condition state=initial
   is a lot like state=special, except no ampersand is required.
*/
#define special	0		/* the state after printing a `char' expression */
#define normal	1		/* the state value in a quoted string */
#define initial	2		/* initial state */

int state = initial;
int print_col = 0;		/* there are at most this many characters on the current line */


/* To print a string on the MPX file, initialize print_col, ensure that
   state=initial, and pass the characters one-at-a-time to print_char.
*/
void
print_char(char cc)
{
    int printable;		/* nonzero if it is safe to print c */
    int l;			/* number of chars in c or the `char' expression */
    int c;			/* equal to cc mod 256, but always positive */

    c = cc & 0377;
    printable = isprint(c) && c < 128;	/* avoid high-bit-on Latin-1 chars */
    if (printable)
	l = 1;
    else if (c < 10)
	l = 5;
    else if (c < 100)
	l = 6;
    else
	l = 7;
    if (print_col + l > line_length - 2) {
	if (state == normal) {
	    putc('"', mpxf);
	    state = special;
	}
	putc('\n', mpxf);
	print_col = 0;
    }
    if (state == normal)
	if (printable)
	    putc(c, mpxf);
	else {
	    fprintf(mpxf, "\"&char%d", c);
	    print_col += 2;
    } else {
	if (state == special) {
	    putc('&', mpxf);
	    print_col++;
	}
	if (printable) {
	    fprintf(mpxf, "\"%c", c);
	    print_col++;
	} else
	    fprintf(mpxf, "char%d", c);
    }
    print_col += l;
    state = printable ? normal : special;
}


/* The end_char_string procedure gets the string ended properly and ensures
   that there is room for |l| more characters on the output line.
*/
void
end_char_string(int l)
{
    while (state > special) {
	putc('"', mpxf);
	print_col++;
	state--;
    }
    if (print_col + l > line_length) {
	putc('\n', mpxf);
	print_col = 0;
    }
    state = initial;		/* get ready to print the next string */
}



/**************************************************************
		Page and Character Output
***************************************************************/

char font_used[FCOUNT];		/* nonzero for fonts used on this page */
int fonts_used;			/* nonzero if any font been used on this page */
int graphics_used;		/* nonzero if any graphics seen on this page */
float str_h1, str_v;		/* corrected start pos for current out string */
float str_h2;			/* where the current output string ends */
int str_f;			/* internal font num for cur. output string */
float str_size;			/* point size for this text string */


/* Before using any fonts we need to define a MetaPost macro for typesetting
   character strings.
*/
void
prepare_font_use(void)
{
    int k;

    for (k = 0; k < nfonts; k++)
	font_used[k] = 0;
    fonts_used = 1;
    fprintf(mpxf, "string n[];\n");
    fprintf(mpxf, "vardef s(expr t,m,x,y) =\n");
    fprintf(mpxf,
	    "  addto p also t scaled(m*1.00375) shifted(x,y); enddef;\n");
}


/* Do what is necessary when the font with internal number f is used for the
   first time on a page.
*/
void
first_use(int f)
{
    font_used[f] = 1;
    fprintf(mpxf, "n%d=\"%s\";\n", font_num[f], texname[f]);
}


/* Print any transformations required by the current Xslant and Xheight
   settings.
*/
void
slant_and_ht(void)
{
    int i = 0;

    if (Xslant != 0.0) {
	fprintf(mpxf, " slanted%.5f", Xslant);
	i++;
    }
    if (Xheight != cursize && Xheight != 0.0 && cursize != 0.0) {
	fprintf(mpxf, " yscaled%.4f", Xheight / cursize);
	i++;
    }
    if (i > 0)
	fprintf(mpxf, "\n ");
}


/* We maintain the invariant that str_f is -1 when there is no output string
   under construction.
*/
void
finish_last_char(void)
{
    float m, x, y;		/* font scale, MetaPost coords of reference point */

    if (str_f >= 0) {
	m = str_size / font_design_size[str_f];
	x = str_h1 * unit;
	y = YCORR - str_v * unit;
	if (fabs(x) >= 4096.0 || fabs(y) >= 4096.0 || m >= 4096.0 || m < 0) {
	    warn("text out of range ignored", "", "");
	    end_char_string(67);
	} else
	    end_char_string(47);
	fprintf(mpxf, ")infont n%d", font_num[str_f]);
	slant_and_ht();
	fprintf(mpxf, ",%.5f,%.4f,%.4f);\n", m, x, y);
	str_f = -1;
    }
}


/* Output character number c in the font with internal number f.
*/
void
set_num_char(int f, int c)
{
    float hh, vv;		/* corrected versions of h, v */
    int i;

    hh = h;
    vv = v;
    for (i = shiftbase[f]; shiftchar[i] >= 0; i++)
	if (shiftchar[i] == c) {
	    hh += (cursize / unit) * shifth[i];
	    vv += (cursize / unit) * shiftv[i];
	    break;
	}
    /* if (c==0) quit("attempt to typeset an invalid character","",""); */
    if (hh - str_h2 >= 1.0 || str_h2 - hh >= 1.0 || vv - str_v >= 1.0
	|| str_v - vv >= 1.0 || f != str_f || cursize != str_size) {
	if (str_f >= 0)
	    finish_last_char();
	else if (!fonts_used)
	    prepare_font_use();	/* first font usage on this page */
	if (!font_used[f])
	    first_use(f);	/* first use of font f on this page */
	fprintf(mpxf, "s((");
	print_col = 3;
	str_f = f;
	str_v = vv;
	str_h1 = hh;
	str_size = cursize;
    }
    print_char(c);
    str_h2 = hh + cursize * charwd[f][c];
}

/* Output a string. */
void
set_string(char *cname)
{
    float hh;			/* corrected version of h, current horisontal position */

    if (!*cname)
	return;
    hh = h;
    set_num_char(curfont, *cname);
    hh += cursize * charwd[curfont][*cname];
    while (*++cname) {
	print_char(*cname);
	hh += cursize * charwd[curfont][*cname];
    }
    h = rint(hh);
    finish_last_char();
}

/* The following initialization and clean-up is required.
*/
void
start_picture(void)
{
    fonts_used = graphics_used = 0;
    str_f = -1;
    str_v = 0.0;
    str_h2 = 0.0;
    str_size = 0.0;
    fprintf(mpxf,
	    "begingroup save C,D,p,s,n; picture p; p=nullpicture;\n");
}

void
stop_picture(void)
{
    if (str_f >= 0)
	finish_last_char();
    fprintf(mpxf, "p endgroup\n");
}



/**************************************************************
			Special Characters
***************************************************************/

/* Given the troff name of a special character, this routine finds its
   definition and copies it to the MPX file.  It also finds the name of
   the vardef macro, puts it in the string pool, and index where the
   string starts.  The name should be C.<something>.
*/
char specintro[] = "vardef ";	/* MetaPost name follows this */
#define speci 7			/* length of the above string */

/* TH: A bit of trickery is added here for case-insensitive 
   file systems. This aliasing allows the CHARLIB directory
   to exist on DVDs, for example.
   It is a hack, I know. I've stuck to  names on TeXLive.
*/

#define test_redo_search  	  if ((c=getc(deff))==EOF)  \
		deff = fsearch(cname, "", CHARLIB_TYPE);        \
	    else ungetc(c,deff)


int
copy_spec_char(char *cname)
{
    int k = 0;			/* how much of specintro so far */
    FILE *deff;
    int c, s;
    if (strcmp(cname, "ao") == 0) {
	deff = fsearch("ao.x", "", CHARLIB_TYPE);
	test_redo_search;
    } else if (strcmp(cname, "lh") == 0) {
	deff = fsearch("lh.x", "", CHARLIB_TYPE);
	test_redo_search;
    } else if (strcmp(cname, "~=") == 0) {
	deff = fsearch("twiddle", "", CHARLIB_TYPE);
	test_redo_search;
    } else {
	deff = fsearch(cname, "", CHARLIB_TYPE);
    }
    while (k < speci) {
	if ((c = getc(deff)) == EOF)
	    quit("No vardef in charlib/", cname, "");
	putc(c, mpxf);
	if (c == specintro[k])
	    k++;
	else
	    k = 0;
    }
    s = poolsize;
    while ((c = getc(deff)) != '(') {
	if (c == EOF)
	    quit("vardef in charlib/", cname, " has no arguments");
	putc(c, mpxf);
	add_to_pool(c);
    }
    putc(c, mpxf);
    add_to_pool('\0');
    while ((c = getc(deff)) != EOF)
	putc(c, mpxf);
    return s;
}


/* When given a character name instead of a number, we need to check if
   it is a special character and download the definition if necessary.
   If the character is not in the current font we have to search the special
   fonts.
*/
Hcell *spec_tab = (Hcell *) 0;

void
set_char(char *cname)
{
    int f, c, *flagp;

    if (*cname == ' ' || *cname == '\t')
	return;
    f = curfont;
    c = *hfind(cname, charcodes[f]);
    if (!hfound()) {
	for (f = specfnt; f != FCOUNT; f = next_specfnt[f]) {
	    c = *hfind(cname, charcodes[f]);
	    if (hfound())
		goto out;
	}
	quit("There is no character ", cname, "");
    }
  out:if (!is_specchar(c))
	set_num_char(f, c);
    else {
	if (str_f >= 0)
	    finish_last_char();
	if (!fonts_used)
	    prepare_font_use();
	if (!font_used[f])
	    first_use(f);
	if (spec_tab == (Hcell *) 0)
	    spec_tab = new_htab;
	flagp = hfind(cname, spec_tab);
	if (*flagp == 0)
	    *flagp = copy_spec_char(cname);	/* this won't be zero */
	fprintf(mpxf, "s(%s(n%d)", &strpool[*flagp], font_num[f]);
	slant_and_ht();
	fprintf(mpxf, ",%.5f,%.4f,%.4f);\n",
		cursize / font_design_size[f], h * unit, YCORR - v * unit);
    }
}



/**************************************************************
			Font Definitions
***************************************************************/

/* Mount the font with troff name nam at external font number n and read any
   necessary font files.
*/
void
do_font_def(int n, char *nam)
{
    int f, k;

    f = *hfind(nam, trfonts);
    if (!hfound())
	quit("Font ", nam, " was not in map file");
    if (font_design_size[f] == 0) {
	read_fontdesc(nam);
	read_tfm(f);
    }
    for (k = 0; k < nfonts; k++)
	if (font_num[k] == n)
	    font_num[k] = -1;
    font_num[f] = n;
}



/**************************************************************
		Time on `makepath pencircle'
***************************************************************/

#define Speed	((float) (PI/4.0))

/* Given the control points of a cubic Bernstein polynomial, evaluate
   it at t.
*/
float
Beval(float *xx, float t)
{
    float zz[4];
    register int i, j;
    for (i = 0; i <= 3; i++)
	zz[i] = xx[i];
    for (i = 3; i > 0; i--)
	for (j = 0; j < i; j++)
	    zz[j] += t * (zz[j + 1] - zz[j]);
    return zz[0];
}


/* Find the direction angle at time t on the path `makepath pencircle'.
   The tables below give the Bezier control points for MetaPost's cubic
   approximation to the first octant of a unit circle.
*/
float xx[4] = { 1.0, 1.0, 0.8946431597, 0.7071067812 };
float yy[4] = { 0.0, 0.2652164899, 0.5195704026, 0.7071067812 };

float
circangle(float t)
{
    float ti;

    ti = floor(t);
    t -= ti;
    return (float) atan(Beval(yy, t) / Beval(xx, t)) + ti * Speed;
}


/* Find the spline parameter where `makepath pencircle' comes closest to
   (cos(a)/2,sin(a)/2).
*/
float
circtime(float a)
{
    int i;
    float t;
    t = a / Speed;
    for (i = 2; --i >= 0;)
	t += (a - circangle(t)) / Speed;
    return t;
}



/**************************************************************
			Troff Graphics
***************************************************************/

float gx, gy;			/* current point for graphics (init. (h,YCORR/unit-v) */

void
prepare_graphics(void)
{
    fprintf(mpxf, "vardef D(expr d)expr q =\n");
    fprintf(mpxf,
	    " addto p doublepath q withpen pencircle scaled d; enddef;\n");
    graphics_used = 1;
}


/* This function prints the current position (gx,gy).  Then if it can read dh dv
   from string s, it increments (gx,gy) and prints "--".  By returning the rest
   of the string s or NULL if nothing could be read from s, it provides the
   argument for the next iteration.
*/
char *
do_line(char *s)
{
    float dh, dv;

    fprintf(mpxf, "(%.3f,%.3f)", gx * unit, gy * unit);
    dh = get_float(s);
    dv = get_float(arg_tail);
    if (arg_tail == NULL)
	return NULL;
    gx += dh;
    gy -= dv;
    fprintf(mpxf, "--\n");
    return arg_tail;
}


/* Function spline_seg() reads two pairs of (dh,dv) increments and prints the
   corresponding quadratic B-spline segment, leaving the ending point to be
   printed next time.  The return value is the string with the first (dh,dv)
   pair lopped off.  If only one pair of increments is found, we prepare to
   terminate the iteration by printing last time's ending point and returning
   NULL.
*/
char *
spline_seg(char *s)
{
    float dh1, dv1, dh2, dv2;

    dh1 = get_float(s);
    dv1 = get_float(arg_tail);
    if (arg_tail == NULL)
	quit("Missing spline increments", "", "");
    s = arg_tail;
    fprintf(mpxf, "(%.3f,%.3f)", (gx + .5 * dh1) * unit,
	    (gy - .5 * dv1) * unit);
    gx += dh1;
    gy -= dv1;
    dh2 = get_float(s);
    dv2 = get_float(arg_tail);
    if (arg_tail == NULL)
	return NULL;
    fprintf(mpxf, "..\ncontrols (%.3f,%.3f) and (%.3f,%.3f)..\n",
	    (gx - dh1 / 6.0) * unit, (gy + dv1 / 6.0) * unit,
	    (gx + dh2 / 6.0) * unit, (gy - dv2 / 6.0) * unit);
    return s;
}


/* Draw an ellipse with the given major and minor axes.
*/
void
do_ellipse(float a, float b)
{
    fprintf(mpxf, "makepath(pencircle xscaled %.3f\n yscaled %.3f",
	    a * unit, b * unit);
    fprintf(mpxf, " shifted (%.3f,%.3f));\n", (gx + .5 * a) * unit,
	    gy * unit);
    gx += a;
}


/* Draw a counter-clockwise arc centered at (cx,cy) with initial and final radii
   (ax,ay) and (bx,by) respectively.
*/
void
do_arc(float cx, float cy, float ax, float ay, float bx, float by)
{
    float t1, t2;

    t1 = circtime(atan2(ay, ax));
    t2 = circtime(atan2(by, bx));
    if (t2 < t1)
	t2 += 8.0;
    fprintf(mpxf, "subpath (%.5f,%.5f) of\n", t1, t2);
    fprintf(mpxf,
	    " makepath(pencircle scaled %.3f shifted (%.3f,%.3f));\n",
	    2.0 * sqrt(ax * ax + ay * ay) * unit, cx * unit, cy * unit);
    gx = cx + bx;
    gy = cy + by;
}



/* string s is everything following the initial `D' in a troff graphics command.
*/
void
do_graphic(char *s)
{
    float h1, v1, h2, v2;
    finish_last_char();
    /* GROFF uses Fd to set fill color for solid drawing objects to the
       default, so just ignore that.
     */
    if (s[0] == 'F' && s[1] == 'd')
	return;
    gx = (float) h;
    gy = YCORR / unit - ((float) v);
    if (!graphics_used)
	prepare_graphics();
    fprintf(mpxf, "D(%.4f) ", LWscale * cursize);
    switch (*s++) {
    case 'c':
	h1 = get_float(s);
	if (arg_tail == NULL)
	    quit("Bad argument in ", s - 2, "");
	do_ellipse(h1, h1);
	break;
    case 'e':
	h1 = get_float(s);
	v1 = get_float(arg_tail);
	if (arg_tail == NULL)
	    quit("Bad argument in ", s - 2, "");
	do_ellipse(h1, v1);
	break;
    case 'A':
	fprintf(mpxf, "reverse ");
	/* fall through */
    case 'a':
	h1 = get_float(s);
	v1 = get_float(arg_tail);
	h2 = get_float(arg_tail);
	v2 = get_float(arg_tail);
	if (arg_tail == NULL)
	    quit("Bad argument in ", s - 2, "");
	do_arc(gx + h1, gy - v1, -h1, v1, h2, -v2);
	break;
    case 'l':
    case 'p':
	while (s != NULL)
	    s = do_line(s);
	fprintf(mpxf, ";\n");
	break;
    case 'q':
	do
	    s = spline_seg(s);
	while (s != NULL);
	fprintf(mpxf, ";\n");
	break;
    case '~':
	fprintf(mpxf, "(%.3f,%.3f)--", gx * unit, gy * unit);
	do
	    s = spline_seg(s);
	while (s != NULL);
	fprintf(mpxf, "--(%.3f,%.3f);\n", gx * unit, gy * unit);
	break;
    default:
	quit("Unknown drawing function", s - 2, "");
    }
    h = (int) floor(gx + .5);
    v = (int) floor(YCORR / unit + .5 - gy);
}



/**************************************************************
		Interpreting Troff Output
***************************************************************/

void
change_font(int f)
{
    for (curfont = 0; curfont < nfonts; curfont++)
	if (font_num[curfont] == f)
	    return;
    quit("Bad font setting", "", "");
}


/* String s0 is everything following the initial `x' in a troff device control
   command.  A zero result indicates a stop command.
*/
int
do_x_cmd(char *s0)
{
    float x;
    int n;
    char *s;

    s = s0;
    while (*s == ' ' || *s == '\t')
	s++;
    switch (*s++) {
    case 'r':
	if (unit != 0.0)
	    quit("Attempt to reset resolution", "", "");
	while (*s != ' ' && *s != '\t')
	    s++;
	unit = get_float(s);
	if (unit <= 0.0)
	    quit("Bad resolution: x", s0, "");
	unit = 72.0 / unit;
	break;
    case 'f':
	while (*s != ' ' && *s != '\t')
	    s++;
	n = get_int(s);
	if (arg_tail == NULL)
	    quit("Bad font def: x", s0, "");
	s = arg_tail;
	while (*s == ' ' || *s == '\t')
	    s++;
	do_font_def(n, s);
	break;
    case 's':
	return 0;
    case 'H':
	while (*s != ' ' && *s != '\t')
	    s++;
	Xheight = get_float(s);
	/* GROFF troff output is scaled
	   groff_out(5): The argument to the s command is in scaled
	   points (units of points/n, where n is the argument
	   to the sizescale command  in the DESC file.)  The
	   argument to the x Height command is also in scaled points.
	   sizescale for groff devps is 1000
	 */
	if (sizescale) {
	    if (unit != 0.0)
		Xheight *= unit;	/* ??? */
	    else
		Xheight /= sizescale;
	}
	if (Xheight == cursize)
	    Xheight = 0.0;
	break;
    case 'S':
	while (*s != ' ' && *s != '\t')
	    s++;
	Xslant = get_float(s) * (PI / 180.0);
	x = cos(Xslant);
	if (-1e-4 < x && x < 1e-4)
	    quit("Excessive slant", "", "");
	Xslant = sin(Xslant) / x;
	break;
    default:
	/* do nothing */ ;
    }
    return 1;
}


/* This routine reads commands from the troff output file up to and including
   the next `p' or `x s' command.  It also calls set_num_char() and set_char()
   to generate output when appropriate.  A zero result indicates that there
   are no more pages to do.
*/
/* GROFF NOTE:
   GNU groff uses an extended device-independent output file format
   documented in groff_out(5). In order to allow parsing of groff's
   output files, this function either needs to be extended to support
   the new command codes, or else the use of the "t" and "u" commands
   must be disabled by removing the line "tcommand" from the DESC file
   in the $(prefix)/lib/groff/devps directory.
*/
int
do_page(void)
{
    char buf[LLENGTH];
    char a, *c, *cc;

    h = v = 0;
    while (fgets(buf, LLENGTH, trf) != NULL) {
	for (c = buf; *c != '\n'; c++)
	    if (*c == '\0')
		quit("Need to increase LLENGTH", "", "");
	*c = '\0';
	lnno++;
	c = buf;
	while (*c != '\0') {
	    switch (*c) {
	    case ' ':
	    case '\t':
	    case 'w':
		c++;
		break;
	    case 's':
		cursize = get_float(c + 1);
		/* GROFF troff output is scaled
		   groff_out(5): The argument to the s command is in scaled
		   points (units of points/n, where n is the argument
		   to the sizescale command  in the DESC file.)  The
		   argument to the x Height command is also in scaled
		   points.
		   sizescale for groff devps is 1000
		 */
		if (sizescale) {
		    if (unit != 0.0)
			cursize *= unit;	/* ??? */
		    else
			cursize /= sizescale;
		}
		goto iarg;
	    case 'f':
		change_font(get_int(c + 1));
		goto iarg;
	    case 'c':
		if (c[1] == '\0')
		    quit("Bad c command in troff output", "", "");
		cc = c + 2;
		goto set;
	    case 'C':
		cc = c;
		do
		    cc++;
		while (*cc != ' ' && *cc != '\t' && *cc != '\0');
		goto set;
	    case 'N':
		set_num_char(curfont, get_int(c + 1));
		goto iarg;
	    case 'H':
		h = get_int(c + 1);
		goto iarg;
	    case 'V':
		v = get_int(c + 1);
		goto iarg;
	    case 'h':
		h += get_int(c + 1);
		goto iarg;
	    case 'v':
		v += get_int(c + 1);
		goto iarg;
	    case '0':
	    case '1':
	    case '2':
	    case '3':
	    case '4':
	    case '5':
	    case '6':
	    case '7':
	    case '8':
	    case '9':
		if (c[1] < '0' || c[1] > '9' || c[2] == '\0')
		    quit("Bad nnc command in troff output", "", "");
		h += 10 * (c[0] - '0') + c[1] - '0';
		c++;
		cc = c + 2;
		goto set;
	    case 'p':
		return 1;
	    case 'n':
		(void) get_int(c + 1);
		(void) get_int(arg_tail);
		goto iarg;
	    case 'D':
		do_graphic(c + 1);
		goto eoln;
	    case 'x':
		if (!do_x_cmd(c + 1))
		    return 0;
		goto eoln;
	    case '#':
		goto eoln;
	    case 'F':
		/* GROFF uses this command to report filename */
		goto eoln;
	    case 'm':
		/* GROFF uses this command to control color */
		goto eoln;
	    case 'u':
		/* GROFF uses this command to output a word with additional
		   white space between characters, not implemented
		 */
		quit("Bad command in troff output\n",
		     "change the DESC file for your GROFF PostScript device, ",
		     "remove tcommand");
	    case 't':
		/* GROFF uses this command to output a word */
		cc = c;
		do
		    cc++;
		while (*cc != ' ' && *cc != '\t' && *cc != '\0');
		a = *cc;
		*cc = '\0';
		set_string(++c);
		c = cc;
		*c = a;
		continue;
	    default:
		quit("Bad command in troff output", "", "");
	    }
	    continue;
	  set:a = *cc;
	    *cc = '\0';
	    set_char(++c);
	    c = cc;
	    *c = a;
	    continue;
	  iarg:c = arg_tail;
	}
      eoln:			/* do nothing */ ;
    }
    return 0;
}


/**************************************************************
			Main Program
***************************************************************/

void
usage(char *name, int status)
{
    FILE *f = status == 0 ? stdout : stderr;
    fputs("Usage: dmp [OPTION]... DITROFFFILE [MPXFILE]\n\
  Translate DITROFFFILE to the MetaPost MPXFILE or standard output.\n\
\n\
--help      display this help and exit\n\
--version   output version information and exit\n", f);
    putc('\n', f);
    fputs("Email bug reports to metapost@tug.org.\n", f);
    exit(status);
}


int
main(int argc, char **argv)
{
    int more;

    fsearch_init(argc, argv);
    trf = stdin;
    mpxf = stdout;
    if (argc == 1) {
	fputs("dmp: Need one or two file arguments.\n", stderr);
	fputs("Try `dmp --help' for more information.\n", stderr);
	exit(1);
    } else if (argc > 1 && (strcmp(argv[1], "--help") == 0
			    || strcmp(argv[1], "-help") == 0)) {
	usage(argv[0], 0);
    } else if (argc > 1 && (strcmp(argv[1], "--version") == 0
			    || strcmp(argv[1], "-version") == 0)) {
	fputs(term_banner, stdout);
	fputs("\nThis program is in the public domain.\n\
Primary author of dmp: John Hobby.\n\
Current maintainer: Taco Hoekwater.\n", stdout);
	exit(0);
    }
    if (argc > 3)
	usage(argv[0], 1);
    if (argc > 1) {
	trf = fopen(argv[1], "r");
	if (trf == (FILE *) 0) {
	    fprintf(stderr, "%s: ", argv[0]);
	    perror(argv[1]);
	    exit(1);
	}
	if (argc > 2) {
	    mpxf = fopen(argv[2], "w");
	    if (mpxf == (FILE *) 0) {
		fprintf(stderr, "%s: ", argv[0]);
		perror(argv[2]);
		exit(1);
	    }
	}
    }
    fprintf(mpxf, "%s\n", banner);
    read_desc();
    read_fmap(dbname);
    if (!gflag)
	read_char_adj(adjname);
    if (do_page()) {
	do {
	    h = 0;
	    v = 0;
	    Xslant = Xheight = 0.0;
	    start_picture();
	    more = do_page();
	    stop_picture();
	    fprintf(mpxf, "mpxbreak\n");
	} while (more);
    }
    exit(0);
}