/* Dvi2ln3 translates a TeX DVI file to an LN03 format file. 

Dvi2ln3 is still being developed. Copyright (c) 1985, 1986 by Digital
Equipment Corporation, Maynard, Massachusetts, USA. Author: Flavio Rose,
...!decwrl!dec-rhea!dec-dvinci!rose. 

Dvi2ln3 is based on the publicly-available program DVItype, written by
David R. Fuchs of Stanford University; and also on earlier DEC programs,
Dvi2lng, Topp and LN03Topp, for the LN01 and LN03 laser printers. This
program is not a DEC product and is not guaranteed to work. 

Dvi2ln3 is written in VAX C. Specific VAX and VMS dependencies have
generally been avoided, however. The reader may find them by searching for
the strings VAX and VMS in this file. 

During development, double square brackets [[ ]] in a comment indicate some
places where the code needs to be improved. 

[[Among the useful things that still need to be done: differentiating
between int and long variables so this can be ported more easily to 16-bit
architectures; testing to see if malloc returns 0; a \special for ROM
fonts.]]

Development history:

Feb. 85:  Did some early work on Dvi2ln3, translating bits and pieces
    	  of Dvi2lng. Concluded, however, that it was better to translate
    	  LN03Topp and Dvi2lng into C first. The reason for this is that code 
    	  which mimics an existing program is easier to write and to test. 

5/15/85:  At this date, the old LN03Topp program has been successfully
    	  translated into C (except for the ability to read files over
    	  DECnet). At this point, did some further cleanup of the Dvi2ln3 
    	  source. 

 6/4/85:  Coding of Dvi2ln3 begins in earnest. Merging bits and
    	  pieces from various places. Chucking chunks and all that
    	  junk from LN03Topp; pass2 is just straightforward translation.

6/22/85:  Cleanup after initial debugging. Ready to distribute.

10/8/85:  Adding \special's to imitate Textset's DVIAPS program.
    	  Corrected bug in parsing of \specials. Version 1.

10/15/85: More changes for specials. Version 2.

11/8/85:  Fixed bug in ln03:defpoint \special. Version 3.

11/15/85: Changed way information about font size is passed back
    	  by add_txf_to_lnf. Add PXL-reading capability. Version 4.

11/21/85: Error handling has been reformed. Still version 4.

12/12/85: Bug correction in handling of plotfile special. Version 5.

1/7/86:	  Clear all fonts from memory at beginning of document. Version 6.

1/16/86:  Fixed bug in dvi2ln3nft.c, nftf was not being closed after use.
    	  Version 7. (Bug found by Mark DeVries.)

3/4/86:	  Support for landscape added -- very easy, if only I had 
    	  known. Fixed bug found by Mark DeVries, error returned
    	  if \special selects device other than LN03. Version 8.

3/28/86:  Conditionalization for Ultrix. #ifndef vms == 
    	  #ifdef ultrix. Still emits 8-bit characters. Should be 
    	  unchanged under VMS. getenv is used to replace 
    	  logicals. Version 9.

4/4/86:   Added support for 7-bit only environments, 
    	  conditionalized on the SEVENBIT symbol. Still version 9.

4/16/86:  Final changes to make compilation under Ultrix 
    	  clean. Still version 9.

*/ 

#ifdef vms
#include stdio
#include ctype
#else
#include <stdio.h>
#include <ctype.h>
#endif

/* Ultrix seems to want this: */

#ifndef vms
char *strchr(), *malloc(), *getenv();
#define SEVENBIT 1
#endif

/* In VMS, we declare all global variables to be globaldef.
This is not really necessary, just an old habit from working
with other VMS languages. It's done with #define's, so it
may easily be undone when porting the program to other
systems. */ 

#ifdef vms
#define GLOBAL globaldef
#define EXTERN globalref
#else
#define GLOBAL 
#define EXTERN extern
#endif


/* Here begins a long list of global variables. */

/* hoff is the horizontal offset in pixels to be added to all dimensions
read in; voff is the corresponding vertical offset. */

GLOBAL int hoff, voff;
GLOBAL FILE *dvifile,*tfmfile,*outfile;

/* Each page in a DVI file is identified by ten longwords, which appear
immediately after each bop (beginning of page) command. Dvi2ln3, like
DVItype, supports certain options that allow one to print only selected
pages. The following variables are used for this purpose. 

Num_pages is a count of how many pages have been passed to the output.
Max_pages is the user-specified maximum number of pages to pass.
How_many_counts denotes the number of identifying longwords to take into
account when searching for the user-specified starting page. The user
specifies the starting page as the first one whose identifying longwords
match certain specified values, stored in start_page. However, identifying
longword i is only required to match the value in start_page[i] if
use_count[i] is nonzero. */ 

GLOBAL long int num_pages,max_pages;
GLOBAL int how_many_counts,use_count[10];
GLOBAL long int start_page[10];

/* When the output file can have no characters with code >
127, the user should employ a dvi2ln3 which is recompiled
with the symbol SEVENBIT defined. Such a dvi2ln3 will run slower
than one which is allowed eight bits, and produce larger
output files. */ 

#ifdef SEVENBIT
GLOBAL int right7; 
#endif

/* FILESPECLEN is the maximum size of a file specification under VMS.
[[Perhaps arrays of fixed size should not be used, but rather malloc should
be employed...]] */ 

#define FILESPECLEN 252

/* landscape says whether we are printing in landscape or portrait. */

GLOBAL char landscape;

/* The main routine deals with the command line arguments, opens the dvi
file, and then calls various other routines to handle the "passes". There
are two passes, each of which involves reading the DVI file from start to
finish; in between, the font load is constructed. */ 

main(argc,argv) 
int argc;
char *argv[];
{
    int status,i,jnam,jext;
    char infnam[FILESPECLEN];

    if (argc < 2) { printf("\n Usage: Dvi2ln3 <filename> <options>");
    	goto exit_label; }

    printf("\n Dvi2ln3 9");

/* [[The following could bomb if argv[1] is longer than FILESPECLEN
characters. Sigh.]] */ 

    strcpy(infnam,argv[1]);

/* The extension of the input file defaults to .dvi. Locate the filename
field within the filespec parameter, set jname to point to beginning, jext
to point to one place after end. [[This code is of course dependent on the
VMS filespec syntax.]] */ 

    find_filename(infnam,&jnam,&jext);
    if (infnam[jext] == '\0') strcat(infnam,".dvi");
    dvifile = fopen(infnam,"r");
    if (dvifile == NULL) { printf("\n Couldn't open dvi file");
    	goto exit_label; }

/* Now decipher the options off the command line. */

#ifdef SEVENBIT
    right7 = 0;
#endif
    max_pages = 1000000000;
    how_many_counts = 0;
    hoff = 300;
    voff = 300;
    landscape = 0;
    for (i=2; i<argc; i++) command_line_options(argv[i]);

/* Now do the passes */

    status = pass1();
    if (status != 0) goto exit_label; 
#ifdef vms
    if (rewind(dvifile) == -1) {
    	printf("\n Couldn't rewind dvi file.");
    	goto exit_label;
    }
#else
    rewind(dvifile);
#endif

    status = open_output_file(infnam,jnam,jext,".ln3");
    if (status != 0) { printf("\n Couldn't open output file");
    	goto exit_label; }

    status = make_font_load();
    if (status != 0) goto exit_label;

    pass2();

    fprintf(outfile,"\033c");
    fclose(dvifile);
    fclose(outfile);

exit_label:
#ifndef vms
    printf("\n");
#endif
    ;
}

/* Find_filename finds the filename part of a filespec
passed in s, returning the index of the first character in
*ns, and the index of the character after the last in *ne.
[[This works under VMS and Unix. MS-DOS still needs work.]]
*/ 

int find_filename(s,ns,ne)
char s[];
int *ns,*ne;
{
    int jnam,jext,j,slen;

    slen = strlen(s);
    jnam = 0;
    for (j = slen-1; j >= 0; j--) {
#ifdef vms
    	if (s[j] == ':' || s[j] == ']' ||
    	    s[j] == '>') {
#else
    	if (s[j] == '/') {
#endif
    	    jnam = j+1;
    	    break;
    	}
    }

    jext = slen;	
    for (j = jnam; j < slen; j++) {
#ifdef vms
    	if (s[j] == '.' || s[j] == ';') {
#else
    	if (s[j] == '.') {
#endif
    	    jext = j;
    	    break;
    	}
    }

    *ns = jnam;
    *ne = jext;
}

/* ERROR HANDLING: Errors should be reported as close to the
source as possible, so that the maximum amount of
information is available to the user to identify the error. 

Errors in the format of DVI or TFM files are not reported
specifically, since there exist programs, DVItype and
TFtoPL, which diagnose errors in such files. This program
accepts some incorrect DVI files, for example, those with a
bad postamble or bad backpointers. [[However, someday we may
rewrite the program to select pages by using these features
of the DVI format, rather than by skipping unwanted pages.]]
*/ 

GLOBAL char *bad_DVI_message = "\nBad DVI file - check it with DVItype"; 

/* Command_line_options reads and processes options off the
string t. At this time, four options are supported. 

The N option sets the maximum number of pages to be printed.
Its syntax is /N=<integer> . 

The H option modifies the default horizontal offset.

The V option modifies the default vertical offset. 

The S option has syntax /S=<pagespec>{.<pagespec>}* where the {}* denotes
repetition, and a <pagespec> is either an integer or * to indicate any
value. An example would be "/S=*.8.3". 

The meaning of the S option is as follows: In a DVI file, pages are
identified by ten longword values which follow each bop (beginning of page)
command. The value of the S option indicates which page to start printing
on. For example, "*.8.3" means start printing at the first page whose
second identifying longword is 8 and third is 3.

The L option says print in landscape.

[[Is a European option needed?]] */

int command_line_options(t)
char *t;
{
    long int i,k;
    char *u;

    while ((t = strchr(t,'/')) != 0) {
	t++;
    	if (toupper(t[0]) == 'N' && t[1] == '=' 
	    	&& (sscanf(&t[2],"%ld",&k) == 1)) 
	    max_pages = k;
    	if (toupper(t[0]) == 'H' && t[1] == '=' 
	    	&& (sscanf(&t[2],"%ld",&k) == 1)) 
	    hoff = k;
    	if (toupper(t[0]) == 'V' && t[1] == '=' 
	    	&& (sscanf(&t[2],"%ld",&k) == 1)) 
	    voff = k;
    	if (toupper(t[0]) == 'L') landscape = 1;
    	else if (toupper(t[0]) == 'S' && t[1] == '=') {
	    t += 2;
	    how_many_counts = 0;
	    for (;;) {
	    	if (t[0] == '*') {
		    use_count[how_many_counts] = 0;
		    how_many_counts++;
		}
		else if (sscanf(t,"%ld",&k) != 0) {
		    use_count[how_many_counts] = 1;
		    start_page[how_many_counts] = k;
		    how_many_counts++;
		} else break;
	    	u = strchr(t,'.');
	    	if (u == 0) break;
    		t = &u[1];
	    }
	}
    } 
}

/* Open_output_file opens one of the output files, using the file pointer
outfile. The name of the output file is obtained by appending the string
ext to the substring of infnam beginning at jnam and ending at jext. 

[[This code contains a VMS dependency. We use creat followed by fdopen to
open the file as a normal VMS file ("rat=cr","rfm=var") rather than a
STREAM_LF file. Beginning with VAX C V2.0, this can be done by just calling
fopen.]] */ 

int open_output_file(infnam,jnam,jext,ext)
char *infnam,*ext;
int jnam,jext;
{
    char outfnam[FILESPECLEN];
    int jj;

    strcpy(outfnam,&infnam[jnam]);
    strcpy(&outfnam[jext-jnam],ext);

#ifdef vms
    jj = creat(outfnam,0,"rat=cr","rfm=var");
#else
    jj = creat(outfnam,0700);
#endif
    if (jj == -1) return(1);
    outfile = fdopen(jj,"w");
    if (outfile == NULL) return(1);

    return(0);
}

/* Bytes are read one by one from the DVI file using getc. We use an
overlay, as suggested in the DVItype documentation, to combine these bytes
into larger integers. [[Note that this technique relies on the fact that
numbers on the VAX are stored with the least significant byte first. The
macros below would have to be changed if the program were to be ported to a
machine architecture for which this is not so.]] 

[[The use of getc is expensive, since getc is a function in VAX C V2.0.
Eventually, one would want to rewrite these macros to work like the old
getc macro.]] */ 

GLOBAL union lc { long int l; unsigned long int ul; char c[4]; 
	    unsigned char uc[4]; } lcx;

#define two_bytes_u lcx.uc[1] = getc(dvifile); \
    lcx.uc[0] = getc(dvifile); lcx.uc[2] = 0; lcx.uc[3] = 0

#define two_bytes_s lcx.c[1] = getc(dvifile); \
    lcx.c[0] = getc(dvifile);  \
    if (lcx.c[1] >= 0) { lcx.uc[2] = 0; lcx.uc[3] = 0 ;} \
    else { lcx.uc[2] = 255; lcx.uc[3] = 255; }

#define three_bytes_u lcx.uc[3] = getc(dvifile); lcx.uc[1] = getc(dvifile); \
    lcx.uc[0] = getc(dvifile); lcx.uc[2] = 0

#define three_bytes_s lcx.c[2] = getc(dvifile); lcx.c[1] = getc(dvifile); \
    lcx.c[0] = getc(dvifile);  \
    lcx.uc[3] = (lcx.c[2] >= 0) ? 0 : 255;

#define four_bytes lcx.c[3] = getc(dvifile); \
    lcx.c[2] = getc(dvifile); lcx.c[1] = getc(dvifile); \
    lcx.c[0] = getc(dvifile); 

/* Knuth's programs like to hardcode fixed maximum sizes for various
things, for example, the maximum number of fonts allowed in a DVI file. In
general, it is preferable to use the C function malloc to allocate storage
as needed. That is what we generally do in this Dvi2ln3, but there are some
residues of the Knuthian approach, like MAXTEXFONTS below. By the way, we
never attempt to return any storage to the system. 

[[Eventually, it would be better to get rid of MAXTEXFONTS and use a linked
list of records instead. There would be no cpu time penalty to using a
linked list, because the function set_curf below does a linear search
through the font array anyway.]]

Txf is a data structure describing a TeX font. */

#define MAXTEXFONTS 100

struct txf { unsigned char chu[256]; int bc, ec; long int space, design_size,
    scaled_size; int nchs; };

GLOBAL struct txf *txfa[MAXTEXFONTS+1];

/* Font_name points to strings containing TeX font names. Those strings are
created with malloc as needed. */ 

GLOBAL char *font_name[MAXTEXFONTS+1]; 

/* Font width information needs to be read from TFM files. TFM is a special
format defined by TeX. Dvi2ln3 stores each width in a longword. DVItype
tries to save space by a two-level width storage method. We just allocate
an array of widths for each font with malloc. 

[[We don't check that font checksums match in Dvi2ln3, because there are a
lot of slightly obsolete TFMs floating around which would result in a
checksum error, but seem to give perfectly reasonable formatted output
nonetheless.]] */ 

GLOBAL long int *font_width[MAXTEXFONTS+1];

/* TeX fonts are referred to by their internal numbers, which go from 0 to
nf-1. The DVI file refers to them by external numbers, hence the array
to_ext used to convert internal numbers to external numbers. Curf is the
internal font number of the current font in the DVI file. */ 

GLOBAL int to_ext[MAXTEXFONTS+1],
    nf,
    curf;

/* In some switch statements, a lot of cases have to be enumerated. We
employ the following Knuthian macro for that purpose: */ 

#define four_cases(_x1) case _x1: case _x1+1: case _x1+2: case _x1+3: 

/* We define a lot of constants corresponding to the DVI operation codes.
These are copied from DVItype. */ 

#define id_byte 2    /* current version of the dvi format */
#define set_char_0 0 /* typeset character 0 and move right */
#define set1 128     /* typeset a character and move right */
#define set_rule 132 /* typeset a rule and move right */
#define put1 133     /* typeset a character */
#define put_rule 137 /* typeset a rule */
#define nop 138      /* no operation */
#define bop 139      /* beginning of page */
#define eop 140      /* ending of page */
#define push 141     /* save the current positions */
#define pop 142      /* restore previous positions */
#define right1 143   /* move right */
#define w0 147       /* move right by |w| */
#define w1 148       /* move right and set |w| */
#define x0 152       /* move right by |x| */
#define x1 153       /* move right and set |x| */
#define down1 157    /* move down */
#define y0 161       /* move down by |y| */
#define y1 162       /* move down and set |y| */
#define z0 166       /* move down by |z| */
#define z1 167       /* move down and set |z| */
#define fnt_num_0 171 /* set current font to 0 */
#define fnt1 235     /* set current font */
#define xxx1 239     /* extension to dvi primitives (\special) */
#define xxx4 242     /* potentially long extension to dvi primitives */
#define fnt_def1 243 /* define the meaning of a font number */
#define pre 247      /* preamble */
#define post 248     /* postamble beginning */
#define post_post 249 /* postamble ending */
#define undefined_command 250

GLOBAL long int mag, num, den;
GLOBAL float conv, unmag_conv;

/* Read_preamble reads the preamble of the dvi file. The comment is thrown
away. The format version number is checked. The magnification, numerator,
and denominator are remembered in the globals mag, num, den. The float
values conv and unmag_conv serve to convert measurements from DVI units to
pixels. */ 

int read_preamble() {
    unsigned int i;
    int j;

    i = getc(dvifile);
    if (i != pre) return(1);
    i = getc(dvifile);
    if (i != id_byte) return(1);
    four_bytes; num = lcx.l;
    if (num <= 0) return(1);
    four_bytes; den = lcx.l;
    if (den <= 0) return(1);
    four_bytes; mag = lcx.l;
    if (mag <= 0) return(1);

    unmag_conv = (num/254000.0) * (300.0/den);
    conv = unmag_conv * (mag/1000.0);

/* Skip over the comment field. */
    
    i = getc(dvifile);
    for (j=0; j<i; j++) getc(dvifile);
    return(0);
}

/* The dvi file format requires us to keep track of various quantities,
among them the horizontal and vertical positions h and v, and four values
referred to simply as x, y, z and w. We also keep pixel-rounded versions
of h and v, called hh and vv. */ 

GLOBAL long h, v, x, y, z, w;
GLOBAL int hh, vv;

/* The following function, copied from DVItype, reads from the DVI file the
first parameter of the current DVI command. In the case of functions whose
first parameter is implicit, such as set_char_0 through set_char_127, the
implicit parameter is returned. */ 

long first_par(o)
int o;
{
    unsigned int i;

    if ((o >= set_char_0) && (o < set_char_0+128))
	return(o-set_char_0);
    if ((o >= fnt_num_0) && (o < fnt_num_0+64))
    	return(o-fnt_num_0);
    switch (o) {
    	case set1:
    	case put1:
    	case fnt1:
    	case xxx1:
    	case fnt_def1:
    	    i = getc(dvifile);
	    return(i);
    	case set1+1:
    	case put1+1:
    	case fnt1+1:
    	case xxx1+1:
    	case fnt_def1+1:
    	    two_bytes_u;
	    return(lcx.ul);
    	case set1+2:
    	case put1+2:
    	case fnt1+2:
    	case xxx1+2:
    	case fnt_def1+2:
    	    three_bytes_u;
	    return(lcx.ul);
    	case right1:
    	case w1:
    	case x1:
    	case down1:
    	case y1:
    	case z1:
	    return(getc(dvifile));
    	case right1+1:
    	case w1+1:
    	case x1+1:
    	case down1+1:
    	case y1+1:
    	case z1+1:
    	    two_bytes_s;
	    return(lcx.l);
    	case right1+2:
    	case w1+2:
    	case x1+2:
    	case down1+2:
    	case y1+2:
    	case z1+2:
    	    three_bytes_s;
	    return(lcx.l);
    	case set_rule:
    	case put_rule:
    	case right1+3:
    	case w1+3:
    	case x1+3:
    	case down1+3:
    	case y1+3:
    	case z1+3:
    	case set1+3:
    	case put1+3:
    	case fnt1+3:
    	case xxx1+3:
    	case fnt_def1+3:
    	    four_bytes;
    	    return(lcx.l);
	case w0:
	    return(w);
	case x0:
	    return(x);
	case y0:
	    return(y);
	case z0:
	    return(z);
	default:
	    return(0);
    }
}

/* Pass1 reads from the DVI file until the last page that has to be
processed, as determined by the page selection data structures. Font
definitions are processed, as are font selections; after the starting page
begins, pass1 records which characters are used from which fonts. Other
commands are ignored in pass1. Return 1 if something goes wrong, e.g. if
the DVI file comes to a premature end. This resembles skip_pages below. */ 

int pass1() {

    unsigned int k;
    long int p;
    int i;
    char startp;
    
    if (read_preamble() != 0) {
    	printf(bad_DVI_message);
    	return(1);
    }

    for (;;) {
	if (feof(dvifile)) {
	    printf(bad_DVI_message);
	    return(1);
	}
	k = getc(dvifile);
	if (k == post) return(0);
	p = first_par(k);
	if (k >= set_char_0 && k < set_char_0+128) k = set1;
	if (k >= fnt_num_0 && k < fnt_num_0+64) k = fnt1;

	switch (k) {
	    case bop:
		startp = 1;
		for (i=0; i<10; i++) {
		    four_bytes;
		    if (i < how_many_counts && use_count[i] &&
			    lcx.l != start_page[i]) startp = 0;
		    }
    		four_bytes;
		if (startp != 0) num_pages = 1;
    		else if (num_pages > 0) {
		    num_pages++;
		    if (num_pages > max_pages) return(0);
		}
    		break;
    	    case set_rule:
    	    case put_rule:
    		four_bytes;
	        break;
	    four_cases(fnt_def1)
	    	i = define_font(p);
	    	if (i != 0) return(1);
	    	break;
	    four_cases(fnt1)
		if (num_pages > 0) set_curf(p);
		break;
            four_cases(set1)
	    four_cases(put1)
	    	if (num_pages > 0)
		    txfa[curf] -> chu[p] = 1;
		break;

/* \special's are currently ignored in pass1, and handled only in pass2.
[[This will change if the putchar special is implemented.]] */ 

	    four_cases(xxx1)
	    	for (; p>0; p--) getc(dvifile);
		break;
            default:
    		break;
	}
    }
/*  return(0); /* Unreachable */
}

/* FONT LOAD BUILDING: The hardest thing Dvi2ln3 has to do is to build an
LN03 font load that contains the glyphs required to print the DVI file. The
following code pertains to that effort. 

LN03 fonts come in two flavors. Left fonts are invoked by character codes
33 to 126. Right fonts are invoked by character codes 161 to 254. Hence: */

#define leftfirst 33
#define rightfirst 161
#define leftlast 126
#define rightlast 254

/* It is believed that there is a maximum of 32 downline-loaded LN03 fonts.
We always deal with these in pairs, using one as a left font, the other as
a right font. Hence we have a maximum of 16 pairs. */ 

#define maxnfonts 16

/* We keep track of the true last character in each LN03 font pair; the
width of each character; and the LN03 name assigned to that pair. */ 

GLOBAL int lastch[maxnfonts];
GLOBAL unsigned char chw[maxnfonts][256];
GLOBAL char fname[maxnfonts][32];

/* Txf is a record structure describing a TeX font. Txfa is an array of txf
records. Txf2lnf describes the mapping between TeX fonts and pairs of LN03
fonts. Because the constructed LN03 font load has just the glyphs that are
needed, we can often cram more than one TeX font into a pair of LN03 fonts.
*/ 

GLOBAL int txf2lnf[MAXTEXFONTS];

/* Maxfontnos reflects the fact that LN03 fonts must be denoted by a number
from 10 to 19 in order to be selected as the LN03's current font. */ 

#define maxfontnos 9

/* The LN03 font-denoting numbers 10-19 have to be allocated among the
fonts. The useno array keeps track of which number a font is using, -1 if
the font currently doesn't have any number. The whouses array says which
font is using a given number. */ 

GLOBAL int useno[maxnfonts],whouses[maxfontnos];

/* After the font load we declare the right and bottom margins we are going 
to use; these are always the maximum allowed values. */

GLOBAL int maxrmar,maxbmar;

/* The global ras_len_added is employed by the font-load-creating code to
communicate how many bytes of raster information it adds to the font load
each time it is called. [[Maybe there should be no EXTERNs in the main code
file, just GLOBALs?]] */ 

EXTERN long ras_len_added;

#define max(x,y) (((x)>(y))?(x):(y))
#define min(x,y) (((x)<(y))?(x):(y))

/* Make_font_load calls on other procedures to generate the LN03 font load.
It writes the opening lines of the output file, too. */ 

int make_font_load() {
    
    int i,j,jj,k,l,fno,maxfno,chsize;
    long int totsize;
    int lnfcnt,txfcnt,the_txf,txf_size,lnfleft;
    int txford[MAXTEXFONTS];
    char cnt[3];

    totsize = 0;
    chsize = 0;
    curf = 0;
    for (i=0; i<maxnfonts; i++) 
    	for (j=0; j<256; j++) chw[i][j] = 0;

    for (jj=0; jj<MAXTEXFONTS; jj++) txf2lnf[jj] = -1;

/* Fill the fname strings with different valid LN03 font names. [[This
initialization could be done statically, but then maxnfonts would be more
hardcoded.]] */ 

    for (i=0; i<maxnfonts; i++) 
        strcpy(fname[i],"U000000002SK00GG0001UZZZZ02F000");
    for (jj=1; jj<maxnfonts; jj++) {
    	sprintf(cnt,"%02d",jj);
    	strncpy(&(fname[jj][5]),cnt,2);
    }

/* The margins are set to values that seem appropriate for American 8 1/2
by 11" paper. It is not clear if this needs to be changed for European A4
paper. Not changing it might deprive Europeans of access to the bottom
1.5cm of their paper. 

It is not clear what the printable area is, or what happens when it is
exceeded. */ 

    if (landscape == 1) {
 	maxrmar = 3300;
 	maxbmar = 2475;    
    } else {
 	maxrmar = 2550;
 	maxbmar = 3300;
    } 

/* In the following, esc[?21 J means print in landscape, esc[?27h means
"advance the carriage by the character width when you set a character",
esc[11h and esc[7 I together mean to interpret all dimensions in escape
sequences as pixel units; esc[?52h means our origin of coordinates is the
upper left edge of the paper; esc[%dt means the "maximum length" of the
paper is maxbmar pixels. */ 

    fprintf(outfile,"\033c");
    if (landscape == 1) fprintf(outfile,"\033[?21 J");
    fprintf(outfile,"\033[?27h\033[11h\033[7 I\033[?52h\033[%dt\n",
    	maxbmar);

    for (i=0; i<maxnfonts; i++) useno[i] = -1;
    for (i=0; i<maxfontnos; i++) whouses[i] = -1;
    maxfno = -1;

/* Write font loading escape sequence onto outf. The ;0y causes all
previously downloaded fonts to be cleared from the LN03's font memory. */ 

    fprintf(outfile,"\033P0;1;0y");

/* Count how many glyphs each font requires. */

    for (fno=0; fno<nf; fno++) {

    	txfa[fno] -> nchs = 0;
    	for(i=0; i<256; i++) 
	    if (txfa[fno] -> chu[i] != 0) txfa[fno] -> nchs++;

	if (txfa[fno] -> nchs > 188)  goto need_empty_slots;
	chsize += txfa[fno] -> nchs;
    }
    printf("\nFont load to contain %d glyphs.",chsize);


/* Now we have to allocate TeX fonts to LN03 font pairs and perform the
actual load. The goal is to use as few LN03 fonts as possible.

I don't know any way to do the allocation optimally, so a first-fit
heuristic is used. 

1. 	Find the largest unassigned TeX font. If none, exit, we're done.
    	Number of glyphs used is the measure of size.

2.	Allocate an LN03 font pair for that TeX font and put the TeX
    	font into it.

3.	Find the largest remaining TeX font that fits in what is left of 
    	that LN03 font pair.

    3.1. if none exists, go to 1.
    3.2. if one exists, put it in the font pair and go back to 3.

The txford array contains the TeX font numbers in the order that they are
assigned. Txfcnt keeps track of how many TeX fonts have been assigned so
far. */ 

    lnfcnt = 0;
    txfcnt = 0;
    for (i=0; i<MAXTEXFONTS; i++) txford[i] = -1;

    while (1) {

/* Find largest unassigned TeX font */

	lnfleft = rightlast-rightfirst+1+leftlast-leftfirst+1;
	txf_size = -1;
	for (j = 0; j < MAXTEXFONTS; j++) {
	    if (txfa[j] != 0 && txf2lnf[j] == -1 
		&& txfa[j] -> nchs > txf_size) {
		txf_size = txfa[j] -> nchs;
		the_txf = j;
	    }
	}
	if (txf_size <= 0)  goto assignment_done;
	if (lnfcnt > maxnfonts)  goto too_complex;
	if (txf_size > lnfleft)  goto need_empty_slots;

/* Now allocate new LN03 font pair and put the current TeX font into it */ 

	txf2lnf[the_txf] = lnfcnt;
	txford[txfcnt] = the_txf;
	txfcnt++;
	k = leftfirst-1;
	for (j = 0; j <= 255; j++) {
	    if (txfa[the_txf] -> chu[j] != 0) {
		k++;
		if (k == leftlast+1)  k = rightfirst;
		lnfleft--;
		txfa[the_txf] -> chu[j] = k; 
	    }
	}
	lastch[lnfcnt] = k;

/* Now try to fill the remaining part of the LN03 font pair using other TeX
fonts */ 

	while (1) {

	    txf_size = -1;
	    for (j = 0; j < MAXTEXFONTS; j++) {
		if (txfa[j] != 0 && txf2lnf[j] == -1
		    && txfa[j] -> nchs > txf_size 
		    && txfa[j] -> nchs <= lnfleft) {
		    txf_size = txfa[j] -> nchs;
		    the_txf = j;
		}	
	    }
	    if (txf_size <= 0)  break;
	    	
	    txf2lnf[the_txf] = lnfcnt;
	    txford[txfcnt] = the_txf;
	    txfcnt++;
	    k = lastch[lnfcnt];
	    for (j=0; j<=255; j++) {
		if (txfa[the_txf] -> chu[j] != 0) {
		    k++;
		    lnfleft--;
		    if (k == leftlast+1) k = rightfirst;
		    txfa[the_txf] -> chu[j] = k; 
		}
	    }
	    lastch[lnfcnt] = k;
	}
	
	lnfcnt++;
    }

assignment_done:

/* At this point, the TeX fonts have been assigned to LN03 font pairs. The
assignment is reflected in the arrays txf2lnf, lastch and txford. It
remains to actually generate the desired font load. This has to be done
carefully, since the function add_txf_to_lnf only supports adding glyphs to
an LN03 font pair in ascending order of character code. */ 

    for (j=0; j<txfcnt; j++) {
	k = txford[j];
	if (j != 0 && txf2lnf[k] != txf2lnf[txford[j-1]])  
	    fprintf(outfile,",\n");
    	add_txf_to_lnf(txf2lnf[k],k);	
    	totsize += ras_len_added;
    }

/* [[At this point we ought to add code that writes a message saying how
much font RAM the load will occupy. But there is no documentation for
determining that! So, we make the following compromise:]] */ 

    printf("\n Approximate size of font load: %ld bytes",totsize);

/* Now output escape sequences to the LN03 that assign the available font
numbers to the first ten font pairs in the load. [[We may want to insert a
few \n's in the following to keep the line from getting too long.]] */ 

    fprintf(outfile,"\n;Dvi2ln3 9 font load\033\\");
    fprintf(outfile,"\033[1;%ds\033[%dt\033[1;%dr",maxrmar,maxbmar,maxbmar);
    for (j=0; j <= min(maxfontnos,lnfcnt-1); j++) {
	useno[j] = j;
	whouses[j] = j;
    	k = fname[j][16];
    	fname[j][16] = '\0';
	fprintf(outfile,"\033P1;1%d}%s\033\\",j,fname[j]);
    	fname[j][16] = k;
    }
    fprintf(outfile,"\033[10m");

    return(0);

too_complex:
    printf("\n Can't construct a font load:");
    printf("\n Dvi file uses too many glyphs from too many different fonts.");
    return(1);

/* [[We need to determine what the real limit is on the number of LN03
fonts, and refine the test to detect if it is being exceeded. Fortunately,
only a very complex DVI file could exceed the limit.]] */ 

need_empty_slots:
    printf("\nFont %s uses > 188 characters. Can't handle that.",
    	font_name[fno]);
    return(1);

/* [[The error message above should be fixed to specify the magnification
of the font also.]] */

}

/* The lines in the LN3 file are limited to lengths of about 100 bytes. We
keep track of how many bytes are written so far in the global lnhp. The
accounting is conservative, so e.g. each integer representing a pixel
position counts as 4 bytes even though it might be shorter. [[One could
easily increase 100 to 200. It is not clear what problems are provoked by
going over, say, 256.]] 

Vpset keeps track of whether the vertical position needs to be output to
the LN03 file before setting any more characters. Hh_old keeps track of the
horizontal position which LN03 thinks it's at. */ 

GLOBAL int ln3p,vpset,hh_old;

#define inc_ln3p(x) ln3p += x; if (ln3p > 100) \
    { ln3p = 0; vpset = 0; hh_old = 30000; }

/* [[In the above macro, hh_old is set to 30000 to mean "a very large
number" (the maximum valid hh for an LN03 is 2550), so as to force the code
below to re-output the true hh. What are the implications of this kludge?
Would it not be more reasonable to have instead an hhset variable?]] */ 

/* A stack of hvxyzw values is kept; the stack pointer is called s.
[[Again, it would be better to make this stack a linked list.]] */ 

#define STACKSIZE 100

GLOBAL long hstack[STACKSIZE], vstack[STACKSIZE], xstack[STACKSIZE], 
    ystack[STACKSIZE], zstack[STACKSIZE], wstack[STACKSIZE];
GLOBAL int hhstack[STACKSIZE], vvstack[STACKSIZE];
GLOBAL int s;

/* DVI files specify distances in units of 2^-16 points. When translating
to a device-specific format, it is necessary to round the DVI distances to
pixel units. This is done by means of the pixel_round macro. 

However, rather than using this macro in the straightforward way, rounding
is often performed by more elaborate techniques, which we call "Stanford
rules" (after John Le Carre's "Moscow rules"). These rules make use of a
parameter MAX_DRIFT, which is roughly the maximum number of pixels that
things are allowed to deviate from straightforward rounding. */ 

#define pixel_round(x) ((int) ((x<0) ? \
    (conv*(x)-0.5) : (conv*(x)+0.5)))
    
#define MAX_DRIFT 2

/* Pass2 reads the dvi file and interprets the commands in it, usually by
calling other routines. The interpretation generally consists of writing
something into the output file, updating the current fonts and positions,
and possibly updating the stack. */ 

int pass2()
{
    int i,j;
    long int p;
    unsigned int k;
    
    if (read_preamble() != 0) {
    	printf(bad_DVI_message);
    	return(1);
    }

    curf = 0;
    ln3p = 0;
    s = 0;
    vpset = 0;
    hh_old = 30000;

/* Skip pages until the desired starting page is reached. A nonzero value
is returned if the starting page is never encountered. */ 

    if (skip_pages() != 0) return(0); 

    for (;;) {
    	if feof(dvifile) { 
            printf(bad_DVI_message);
    	    return(1); }
    	k = getc(dvifile);
    	if (k == post) return(0);
    	if (k >= undefined_command) {
            printf(bad_DVI_message);
	    return(1); }
    	
	p = first_par(k);    

/* If the opcode is an "implicit parameter" opcode, either set_char_n and
fnt_num_n, we change it to an explicit parameter opcode to make the case
jumps more reasonable. */ 

    	if (k >= set_char_0 && k < set_char_0+128) k = set1;
    	if (k >= fnt_num_0 && k < fnt_num_0+64) k = fnt1;

    	j = do_command(k,p);
    	if (j == 2) return(0); /* done with the required number of pages */
    	else if (j == 1) return(1); /* error encountered, stop */

    }
}

GLOBAL long first_counter;

/* Read from the DVI file until the starting page condition is met. Return
1 if something goes wrong, or if the DVI file comes to an end. This 
function is copied quite closely from DVItype. */ 

int skip_pages() {

    unsigned int k;
    int i;
    long p;
    char startp;
    
    for (;;) {
	if (feof(dvifile)) return(1);
	k = getc(dvifile);
	if (k == post) return(1);
	p = first_par(k);
	if (k >= set_char_0 && k < set_char_0+128) k = set1;
	if (k >= fnt_num_0 && k < fnt_num_0+64) k = fnt1;

	switch (k) {
	    case bop:
		startp = 1;
		for (i=0; i<10; i++) {
		    four_bytes;
    		    if (i == 0) first_counter = lcx.l;
		    if (i < how_many_counts && use_count[i] &&
			    lcx.l != start_page[i]) startp = 0;
		    }
    		four_bytes;
		if (startp != 0) { 
		    v = 0; vv = 0; h = 0; hh = 0;
	    	    printf("\n [%ld]",first_counter);
    		    num_pages = 1; return(0); }
    		break;
    	    case set_rule:
    	    case put_rule:
    		four_bytes;
	        break;
	    four_cases(fnt_def1)

/* [[Why are we defining fonts again here? Once, in pass1, ought to have
been enough...]] */ 

	    	i = define_font(p);
	    	if (i != 0) return(1);
	    	break;
	    four_cases(xxx1)
	    	for (; p>0; p--) getc(dvifile);
		break;
            default:
    		break;
	}
    }
/*  return(0); /* Unreachable */
}

/* Do_command performs the DVI command of code k, assuming the "first
parameter" is p. It is assumed that k is not one of set_char0 through
set_char127. */ 

int do_command(k,p)
int k;
long p;
{
    int i,j,l,lnf;

    switch (k) {
	four_cases(fnt_def1)
	    define_font_pass2();
	    break;

/* It is possible that the dvi file sets some glyphs off the page. No error
message is given, since the user will generally see what is happening in
the output (plus, if Dvi2ln3 gives an error message, users will complain
about Dvi2ln3 even though the error is in their TeX file). 

In most cases, dvi2ln3 takes no special action at all, since the LN03 will
clip the glyphs for us. Unfortunately, the LN03 doesn't let us specify
negative horizontal or vertical positions, so we have to clip glyphs at
such positions away ourselves. Also, if one sets at a position below the
bottom margin, the LN03 will eject a page, so glyphs that are set below
that margin also have to be clipped by hand. 

The following code accomplishes that: */ 

	four_cases(put1)
	four_cases(set1)

    	    if (vv+voff > 0 && vv+voff <= maxbmar && hh+hoff > 0) {
		if (!vpset) {
		    fprintf(outfile,"\n\033[%dd",vv+voff);
		    fprintf(outfile,"\033[%d`",hh+hoff);
		    ln3p = 16;
		    vpset = 1;
		    hh_old = hh;
		}
		if (hh_old != hh) {
		    if (hh > hh_old) fprintf(outfile,"\033[%da",hh-hh_old);
		    else fprintf(outfile,"\033[%d`",hh+hoff);
		    ln3p += 7;
		}

#ifndef SEVENBIT
		putc(txfa[curf] -> chu[p],outfile);
#else 
    		if (txfa[curf] -> chu[p] > 127) {
    		    if (right7 == 0) {
			fputs("\033n",outfile);
			inc_ln3p(2);
			right7 = 1;
    		    }
		    putc(txfa[curf] -> chu[p]-128,outfile);
    		} else {
    		    if (right7 == 1) {
    		        putc(15,outfile);
			inc_ln3p(1);
			right7 = 0;			
    		    }
		    putc(txfa[curf] -> chu[p],outfile);
    		}
#endif
		inc_ln3p(1);
    	    }
	    if (k >= put1) {
    	        hh_old = hh+chw[txf2lnf[curf]][txfa[curf] -> chu[p]];
		break;
	    }
	    h += font_width[curf][p];

/* In rounding h to generate the pixel-position hh, Stanford rules (see
above) come into play. We set the new hh (horizontal position in pixels) to
the value obtained by adding the pixel width of the character being set to
the current position. We then correct this value so that it does not exceed
the rounded version of the true position by more than MAX_DRIFT pixels.

Note that if we did not apply Stanford rules here, or equivalently if we
set MAX_DRIFT to zero, many more set-X-position commands would appear in
the output. */

	    hh += chw[txf2lnf[curf]][txfa[curf] -> chu[p]];
    	    hh_old = hh;
	    l = pixel_round(h);
	    if (hh-l > MAX_DRIFT) hh = l+MAX_DRIFT;
	    else if (l-hh > MAX_DRIFT) hh = l-MAX_DRIFT;
	    break;

	four_cases(fnt1)
	    set_curf(p);
	    lnf = txf2lnf[curf];
	    if (useno[lnf] == -1) {
		useno[whouses[maxfontnos]] = -1;
		useno[lnf] = maxfontnos;
		whouses[maxfontnos] = lnf;
		fprintf(outfile,"\033P1;1%d}%16s\033\\",maxfontnos,
    			fname[lnf]);
		inc_ln3p(26);
	    }
	    fprintf(outfile,"\033[1%dm",useno[lnf]);
	    inc_ln3p(5);
	    break;

	case set_rule:
	case put_rule: 

/* When converting rule dimensions to pixel dimensions, we do not follow
Stanford rules. Rather, we just round the true positions to obtain the
pixel positions. This avoids unsightly gaps between rules. [[It should not
cause much of a problem with typical rule applications (ruled tables,
fraction bars)...but perhaps with large delimiters there might be some
difficulty. This needs more thought...]] */ 

	    four_bytes; 
	    if (p >= 0 && lcx.l >= 0) 
		do_rule(pixel_round(h),
			pixel_round(v-p),pixel_round(h+lcx.l),
			pixel_round(v));
	    if (k == set_rule) {
    		h += lcx.l;
		hh = pixel_round(h);
	    }
	    break;

	 case push:
	    s++;
	    if (s == STACKSIZE) {
		printf("\n Stack too deep for Dvi2ln3");
		return(1);
	    }
	    xstack[s] = x;
	    ystack[s] = y;
	    vstack[s] = v;
	    hstack[s] = h;
	    vvstack[s] = vv;
	    hhstack[s] = hh;
	    wstack[s] = w;
	    zstack[s] = z;
	    break;

	case pop:
	    if (s == 0) { 		   
		printf(bad_DVI_message); 
		return(1); 
	    }
    	    if (vv != vvstack[s]) vpset = 0;
	    x = xstack[s]; 
	    y = ystack[s];    
	    v = vstack[s]; 
	    h = hstack[s];    
	    vv = vvstack[s]; 
	    hh = hhstack[s];    
	    w = wstack[s]; 
	    z = zstack[s];
	    s--; 
	    break; 

	four_cases(xxx1)
    	    do_special_pass2(p);
	    break;

	case bop:

/* If we've done the required number of pages, we'll skip the rest of the
DVI file. If not, type the first parameter of bop on the user's terminal
the way TeX does, to give an indication of progress. */ 

    	    if (num_pages == max_pages) return(2);
	    v = 0; vv = 0; h = 0; hh = 0;
    	    vpset = 0; hh_old = 100000;
    	    four_bytes;
	    if (num_pages%12 == 0) printf("\n");
            first_counter = lcx.l;
	    printf(" [%ld]",lcx.l);
            num_pages++;
	    for (i = 0; i<40; i++) getc(dvifile); 
	    break;

	case eop:
	    fprintf(outfile,"\n\f");
	    ln3p = 0;
	    break;

/* Now we have to consider the cases for pure motion. */

	four_cases(right1)
	    set_h(h+p);
	    break;
	four_cases(x1)
	    x = p;
	case x0:
	    set_h(h+x);
	    break;
	four_cases(y1)
	    y = p;
	case y0:
	    set_v(v+y);
	    break;
	four_cases(w1)
	    w = p;
	case w0:
	    set_h(h+w);
	    break;
	four_cases(z1)
	    z = p;
	case z0:
	    set_v(v+z);
	    break;
	four_cases(down1)
	    set_v(v+p);
	    break;

    }	
    return(0);
}

/* Set_curf sets the current font to external number p. Note that the
current font is maintained as an internal font number. */ 

int set_curf(p)
int p;
{
    to_ext[nf] = p;
    curf = 0;
    while (to_ext[curf] != p) { curf++; }    
}

/* Define_font processes a font definition from the DVI file. The TFM file
for the font is read at this point from the directory TEX$FONTS. */ 

int define_font(e)
int e;
{
    int i;
    unsigned char p,n;
    if (e == MAXTEXFONTS) { printf("\n Too many fonts for Dvi2ln3");
    	return(1); }
    txfa[nf] = (struct txf *)malloc(sizeof(struct txf));
    to_ext[nf] = e;
    four_bytes;
    four_bytes;
    txfa[nf] -> scaled_size = lcx.l;
    four_bytes;
    txfa[nf] -> design_size = lcx.l;
    for (i=0; i<256; i++) txfa[nf] -> chu[i] = '\0';
    p = getc(dvifile); n = getc(dvifile);
    font_name[nf] = malloc(p+n+1);
    for (i=0; i<p+n; i++) { font_name[nf][i] = getc(dvifile); }
    font_name[nf][p+n] = '\0';

    if (txfa[nf] -> scaled_size <= 0 || txfa[nf] -> scaled_size >=
    	8*8*8*8*8*8*8*8*8) {
    	printf("\n Font %s has a bad scaled size",font_name[nf]);
    	return(1);
    }
    if (txfa[nf] -> design_size <= 0 || txfa[nf] -> design_size >= 
    	8*8*8*8*8*8*8*8*8) {
    	printf("\n Font %s has a bad design size",font_name[nf]);
    	return(1);
    }

/* We follow DVItype and compute for each font a "space" parameter which is
one-sixth of the scaled design size. This parameter is used in rounding the
horizontal position to pixels according to "Stanford rules." See the
function set_h below. */ 

    txfa[nf] -> space = txfa[nf] -> scaled_size/6;     

    i = read_tfm_file();
    if (i != 0) return(i);
    nf++;
    return(0); 

}

/* TFM files, like the DVI file, are read with getc, foolish as that may
seem. We use the same overlays that are used for merging DVI bytes into
longwords. However, since the TFM file consists of longwords, only
tfm_longword is need. [[This is also VAX dependent. It would not be
possible to use stdio's longword reading function getw here, because the
bytes have to be reversed.]] */ 

#define tfm_longword { lcx.uc[3] = getc(tfmfile); \
    lcx.uc[2] = getc(tfmfile); lcx.uc[1] = getc(tfmfile); \
    lcx.uc[0] = getc(tfmfile); }

/* Read_tfm_file obtains the character widths from the TFM file
corresponding to font nf. */ 

int read_tfm_file() {

    int i,lh,nw;
    int info[256];
    long z,alpha,beta;
    long width[256];

    open_tfm_file();
    if (tfmfile == NULL) {
    	printf("\n Can't open TFM file for font %s",font_name[nf]);
    	return(1); }

/* The TFM format is described in some issue of the TUGBoat (TeX users'
group newsletter), and in the comments to the program TFtoPL. Here we
summarize those aspects of TFM format that are relevant to the task of
extracting the widths of the characters. 

The first 24 bytes of a TFM file contain twelve 16-bit integers that give
the lengths of the various subsequent portions of the file. The ones
relevant to our purposes are LH, length of the header data, BC, the
smallest character code in the font, EC, the largest character code in the
font, and NW, number of words in the width table. So, we read those right
now, and then skip over the remainder, and then over a set of LH longwords
called the "header." */ 

    tfm_longword; 
    lh = 256*lcx.uc[1] + lcx.uc[0];
    tfm_longword;
    txfa[nf] -> bc = 256*lcx.uc[3] + lcx.uc[2];
    txfa[nf] -> ec = 256*lcx.uc[1] + lcx.uc[0];
    tfm_longword;
    nw = 256*lcx.uc[3] + lcx.uc[2];
    if (txfa[nf] -> bc > 255 || txfa[nf] -> ec > 255 ||
    	txfa[nf] -> bc > txfa[nf] -> ec || nw > 256) {
    	printf("\n Bad TFM file for font %s",font_name[nf]);
    	return(1);
    }    	

    for(i=0; i<lh+3; i++) tfm_longword;

/* After the header, there are two arrays in the TFM file that interest us.
The first, INFO, is EC-BC+1 longwords long and contains pointers to the
second, WIDTH, which is NW longwords long. For each character i, the width
of i is WIDTH[INFO[i-BC]]. We read these arrays into memory. */ 

    for(i=0; i<txfa[nf] -> ec-txfa[nf] -> bc+1; i++) {
    	tfm_longword;
    	if (lcx.uc[3] >= nw) {
	    printf("\n Bad TFM file for font %s",font_name[nf]);
	    return(1);
	}	    
    	info[i] = lcx.uc[3];
    }

/* The widths are stored in a rather strange format known as a "fix-word."
A nonnegative width is expressed in "fix-word" format by expressing it in
units of 2^-20 times the design size. A negative width is expressed in
"fix-word" format by expressing its negative in those units, and then
changing the most significant byte to 255. 

One needs to convert these widths into DVI units, multiplying by the scaled
design size according to a certain arcane algorithm. The algorithm is
copied from DVItype, to which we refer the reader for an explanation. */ 

    z = txfa[nf] -> scaled_size;
    alpha = 16*z; beta = 16;
    while (z >= 4*(8*8*8*8*8*8*8)) { z = z/2; beta = beta/2; }
    for(i=0; i<nw; i++) {
    	tfm_longword;
    	width[i] = ( ( (lcx.uc[0]*z)/256 + lcx.uc[1]*z )/256  + 
    		lcx.uc[2]*z)/beta;
    	if (lcx.uc[3] == 255) width[i] -= alpha;
    }

    fclose(tfmfile);

/* Using these two arrays, we now compute the widths of the characters in
the fonts and place them into two malloc'ed arrays, one for the widths in
DVI units, one for the width in pixel units. */ 

    font_width[nf] = (long int *)malloc(4*(txfa[nf] -> ec+1));
    
    for (i=0; i<txfa[nf] -> bc; i++) font_width[nf][i] = 0;
    for (i=txfa[nf] -> bc; i <= txfa[nf] -> ec; i++) 
	font_width[nf][i] = width[info[i-txfa[nf] -> bc]];
    return(0);
}

/* Open_tfm_file finds and opens the tfm file corresponding to a font nf.
The global file variable tfmfile is used to hold the file pointer. [[This
function will not work if the TFM file lies over the net on a VMS V3.x
host, because C file opens do not work in such circumstances. The problem
can be ignored, because eventually there should be very few VMS V3.x hosts
left.]] */ 

int open_tfm_file () {

    int jext,jnam;
    char filespec[FILESPECLEN];

#ifndef vms
    char *texfontdir;
#endif


    find_filename(font_name[nf],&jnam,&jext);
    filespec[0] = '\0';

/* If there is no directory part, fill in using the logical tex$fonts */ 

#ifdef vms
    if (jnam == 0) strcpy(filespec,"tex$fonts:");
#else
    if (jnam == 0) { 
    	texfontdir = getenv("TEX_FONTS");             
	strcpy(filespec,texfontdir);
	strcat(filespec,"/");
    }
#endif
    strcat(filespec,font_name[nf]);

/* if there is no extension, add the extension ".tfm" */

    if (font_name[nf][jext] == '\0') strcat(filespec,".tfm");
    tfmfile = fopen(filespec,"r");

}

/* Define_font_pass2 skips a font definition from the DVI file. */ 

int define_font_pass2()
{
    unsigned char p,n;
    int i;
    four_bytes;
    four_bytes;
    four_bytes;
    p = getc(dvifile); n = getc(dvifile);
    for (i=0; i<p+n; i++) getc(dvifile);
}

/* Do_rule writes into the ln3 file the escape sequence corresponding to a
rule. The rule is silently clipped to fit on the page. */ 

int do_rule(xx0,yy0,xx1,yy1) 
int xx0,yy0,xx1,yy1;
{
    int j;

    xx0 = min(xx0+hoff,maxrmar);
    xx1 = min(xx1+hoff,maxrmar);
    xx0 = max(xx0,0);
    xx1 = max(xx1,0);
    yy0 = min(yy0+voff,maxbmar);
    yy1 = min(yy1+voff,maxbmar);
    yy0 = max(yy0,0);
    yy1 = max(yy1,0);
    if (xx0 > xx1) { j = xx0; xx0 = xx1; xx1 = j; }
    if (yy0 > yy1) { j = yy0; yy0 = yy1; yy1 = j; }
    	    
    if ((yy1 != yy0 && xx1 != xx0)) {
	fprintf(outfile,"\033[1;%d;%d;%d;%d!|",
	    xx0,yy0,yy1-yy0,xx1-xx0);
	inc_ln3p(25);
    }
}

/* Set_v is called to execute vertical-position-altering commands, other
than pops. It modifies v and vv, and outputs the vertical position to the
LN3 file. We don't follow Stanford rules here. They sometimes set the
vertical position in pixels vv to something other than the rounded value of
v. Not following Stanford rules implies, for example, that the relative
vertical positions of an accent and its accentee may differ by one pixel
according to how the baseline of the accentee gets rounded. [[This should
perhaps be fixed.]] */ 

int set_v(v1)
int v1;
{
    int l;

    l = pixel_round(v1);
    v = v1;
    vv = l;
    vpset = 0;
}    

/* Set_h is called whenever a DVI command is encountered that alters the
horizonal position, other than a set_char, set_rule or pop. It sets h to
the new value, and alters hh according to Stanford rules. */ 

int set_h(new_h)
int new_h;   
{
    int l,old_hh;

    old_hh = hh;
    l = pixel_round(new_h);
    if (txfa[curf] == 0 || new_h-h >= txfa[curf] -> space
    	|| new_h-h <= -4*txfa[curf] -> space) hh = l;
    else {
    	hh += pixel_round(new_h-h);
        if (hh-l > MAX_DRIFT) hh = l+MAX_DRIFT;
    	else if (hh-l < -MAX_DRIFT) hh = l-MAX_DRIFT;
    }
    h = new_h;
    return(0);
}