ref: e610ffaf1b7847e82c18a1b9c687cdd7676f86c2
dir: /sys/src/cmd/postscript/postbgi/postbgi.c/
/*
*
* postbgi - BGI (Basic Graphical Instructions) to PostScript translator.
*
* A simple program that translates BGI files into PostScript. Probably only
* useful in Computer Centers that support STARE or PRISM plotters. Most of the
* code was borrowed from the corresponding program that was written for printers
* that understand Impress.
*
* Extending the original program to handle PRISM jobs was not trivial. Graphics
* packages that support PRISM occasionally use BGI commands that I ignored in the
* STARE implementation. Subroutines, color requests, patterns (for filling), and
* filled trapeziods were the most important omissions. All are now implemented,
* and at present only repeats, filled slices, and raster rectangles are missing.
*
* Pattern filling results were not always predictable or even good, unless the
* halftone screen definitions were changed and scaling was adjusted so one pixel
* in user space mapped into an integral number of device space pixels. Doing that
* makes the resulting PostScript output device dependent, but was often necessary.
* I've added two booleans to the PostScript prologue (fixscreen and scaletodevice)
* that control what's done. By default both are false (check postbgi.ps) but can
* be set to true on the command line using the -P option or by hand by changing
* the definitions in the prologue. A command line that would set fixscreen and
* scaletodevice true would look like,
*
* postbgi -P"/fixscreen true" -P"/scaletodevice true" file >file.ps
*
* Several other approaches are available if you want to have your spooler handle
* STARE and PRISM jobs differently. A boolean called prism is defined in the
* prologue (postbgi.ps) and if it's set to true PostScript procedure setup will
* set fixscreen and scaletodevice to true before anything important is done. That
* means the following command line,
*
* postbgi -P"/prism true" file >file.ps
*
* accomplishes the same things as the last example. Two different prologue files,
* one for STARE jobs and the other for PRISM, could be used and the spooler could
* point postbgi to the appropriate one using the -L option. In that case the only
* important difference in the two prologues would be the definition of prism. The
* prologue used for PRISM jobs would have prism set to true, while the STARE
* prologue would have it set to false.
*
* Also included is code that ties lines to device space coordinates. What you get
* is a consistent line thickness, but placement of lines won't be exact. It's a
* trade-off that should be right for most jobs. Everything is implemented in the
* prologue (postbgi.ps) and nothing will be done if the linewidth is zero or if
* the boolean fixlinewidth (again in postbgi.ps) is false. Once again the -P
* option can be used to set fixlinewidth to whatever you choose.
*
* BGI supports color mixing but PostScript doesn't. BGI files that expect to mix
* colors won't print properly. PostScript's fill operator overlays whatever has
* already been put down. Implementing color mixing would have been a terribly
* difficult job - not worth the effort!
*
* The PostScript prologue is copied from *prologue before any of the input files
* are translated. The program expects that the following PostScript procedures
* are defined in that file:
*
* setup
*
* mark ... setup -
*
* Handles special initialization stuff that depends on how the program
* was called. Expects to find a mark followed by key/value pairs on the
* stack. The def operator is applied to each pair up to the mark, then
* the default state is set up.
*
* pagesetup
*
* page pagesetup -
*
* Does whatever is needed to set things up for the next page. Expects
* to find the current page number on the stack.
*
* v
*
* dx1 dy1 ... dxn dyn x y v -
*
* Draws the vector described by the numbers on the stack. The top two
* numbers are the coordinates of the starting point. The rest of the
* numbers are relative displacements from the preceeding point.
*
* pp
*
* x1 y1 ... xn yn string pp -
*
* Prints string, which is always a single character, at the points
* represented by the rest of the numbers on the stack.
*
* R
*
* n deltax deltay x y R -
*
* Creates a rectangular path with its lower left corner at (x, y) and
* sides of length deltax and deltay. The resulting path is stroked if
* n is 0 and filled otherwise.
*
* T
*
* dx3 dy3 dx2 dy2 dx1 dy1 x y T -
*
* Fills a trapezoid starting at (x, y) and having relative displacements
* given by the (dx, dy) pairs.
*
* t
*
* angle x y string t -
*
* Prints string starting at (x, y) using an orientation of angle degrees.
* The PostScript procedure can handle any angle, but BGI files will only
* request 0 or 90 degrees. Text printed at any other orientation will be
* vector generated.
*
* p
*
* x y p -
*
* Called to mark the point (x, y). It fills a small circle, that right
* now has a constant radius. This stuff could probably be much more
* efficient?
*
* l
*
* array l -
*
* Sets the line drawing mode according to the description given in
* array. The arrays that describe the different line styles are declared
* in STYLES (file posttek.h), although it would be better to have them
* defined in the prologue.
*
* c
*
* red green blue c -
*
* Sets the current PostScript RGB color using setrgbcolor. Also used for
* selecting appropriate patterns as colors.
*
* f
*
* bgisize f -
*
* Changes the size of the font that's used to print text. bgisize is a
* grid separation in a 5 by 7 array in which characters are assumed to
* be built.
*
* done
*
* done
*
* Makes sure the last page is printed. Only needed when we're printing
* more than one page on each sheet of paper.
*
* The default line width is zero, which forces lines to be one pixel wide. That
* works well for 'write to black' engines but won't be right for 'write to white'
* engines. The line width can be changed using the -w option, or you can change
* the initialization of linewidth in the prologue. Code in the prologue supports
* the generation of uniform width lines when linewidth is non-zero and boolean
* fixlinewidth is true.
*
* Many default values, like the magnification and orientation, are defined in
* the prologue, which is where they belong. If they're changed (by options), an
* appropriate definition is made after the prologue is added to the output file.
* The -P option passes arbitrary PostScript through to the output file. Among
* other things it can be used to set (or change) values that can't be accessed by
* other options.
*
*/
#include <stdio.h>
#include <sys/types.h>
#include <fcntl.h>
#include <signal.h>
#include <math.h>
#include <ctype.h>
#ifdef plan9
#define isascii(c) ((unsigned char)(c)<=0177)
#endif
#include "comments.h" /* PostScript file structuring comments */
#include "gen.h" /* general purpose definitions */
#include "path.h" /* for the prologue */
#include "ext.h" /* external variable declarations */
#include "postbgi.h" /* a few definitions just used here */
char *optnames = "a:c:f:m:n:o:p:w:x:y:A:C:E:J:L:P:R:DI";
char *prologue = POSTBGI; /* default PostScript prologue */
char *formfile = FORMFILE; /* stuff for multiple pages per sheet */
int formsperpage = 1; /* page images on each piece of paper */
int copies = 1; /* and this many copies of each sheet */
char *styles[] = STYLES; /* descriptions of line styles */
int hpos = 0; /* current horizontal */
int vpos = 0; /* and vertical position */
int bgisize = BGISIZE; /* just the character grid spacing */
int linespace; /* distance between lines of text */
int bgimode; /* character or graph mode */
int in_subr = FALSE; /* currently defining a subroutine */
int in_global = FALSE; /* to save space with subroutine defs */
int subr_id = 0; /* defining this subroutine */
int shpos = 0; /* starting horizontal */
int svpos = 0; /* and vertical positions - subroutines */
Disp displacement[64]; /* dx and dy after a subroutine call */
Fontmap fontmap[] = FONTMAP; /* for translating font names */
char *fontname = "Courier"; /* use this PostScript font */
int page = 0; /* page we're working on */
int printed = 0; /* printed this many pages */
FILE *fp_in = stdin; /* read from this file */
FILE *fp_out = NULL; /* and write stuff here */
FILE *fp_acct = NULL; /* for accounting data */
/*****************************************************************************/
main(agc, agv)
int agc;
char *agv[];
{
/*
*
* A program that converts BGI (Basic Graphical Instructions) files generated by
* packages like GRAFPAC and DISSPLA into PostScript. It does an adequate job but
* is far from perfect. A few things still haven't been implemented (eg. repeats
* and raster rectangles), but what's here should be good enough for most of our
* STARE and PRISM jobs. Color mixing (in PRISM jobs) won't work on PostScript
* printers, and there's no chance I'll implement it!
*
*/
argc = agc; /* global so everyone can use them */
argv = agv;
prog_name = argv[0]; /* just for error messages */
init_signals(); /* set up interrupt handling */
header(); /* PostScript header comments */
options(); /* command line options */
setup(); /* for PostScript */
arguments(); /* followed by each input file */
done(); /* print the last page etc. */
account(); /* job accounting data */
exit(x_stat); /* everything probably went OK */
} /* End of main */
/*****************************************************************************/
init_signals()
{
/*
*
* Make sure we handle interrupts.
*
*/
if ( signal(SIGINT, interrupt) == SIG_IGN ) {
signal(SIGINT, SIG_IGN);
signal(SIGQUIT, SIG_IGN);
signal(SIGHUP, SIG_IGN);
} else {
signal(SIGHUP, interrupt);
signal(SIGQUIT, interrupt);
} /* End else */
signal(SIGTERM, interrupt);
} /* End of init_signals */
/*****************************************************************************/
header()
{
int ch; /* return value from getopt() */
int old_optind = optind; /* for restoring optind - should be 1 */
/*
*
* Scans the option list looking for things, like the prologue file, that we need
* right away but could be changed from the default. Doing things this way is an
* attempt to conform to Adobe's latest file structuring conventions. In particular
* they now say there should be nothing executed in the prologue, and they have
* added two new comments that delimit global initialization calls. Once we know
* where things really are we write out the job header, follow it by the prologue,
* and then add the ENDPROLOG and BEGINSETUP comments.
*
*/
while ( (ch = getopt(argc, argv, optnames)) != EOF )
if ( ch == 'L' )
prologue = optarg;
else if ( ch == '?' )
error(FATAL, "");
optind = old_optind; /* get ready for option scanning */
fprintf(stdout, "%s", CONFORMING);
fprintf(stdout, "%s %s\n", VERSION, PROGRAMVERSION);
fprintf(stdout, "%s %s\n", DOCUMENTFONTS, ATEND);
fprintf(stdout, "%s %s\n", PAGES, ATEND);
fprintf(stdout, "%s", ENDCOMMENTS);
if ( cat(prologue) == FALSE )
error(FATAL, "can't read %s", prologue);
fprintf(stdout, "%s", ENDPROLOG);
fprintf(stdout, "%s", BEGINSETUP);
fprintf(stdout, "mark\n");
} /* End of header */
/*****************************************************************************/
options()
{
int ch; /* option name - from getopt() */
/*
*
* Reads and processes the command line options.
*
*/
while ( (ch = getopt(argc, argv, optnames)) != EOF ) {
switch ( ch ) {
case 'a': /* aspect ratio */
fprintf(stdout, "/aspectratio %s def\n", optarg);
break;
case 'c': /* copies */
copies = atoi(optarg);
fprintf(stdout, "/#copies %s def\n", optarg);
break;
case 'f': /* new font */
fontname = get_font(optarg);
fprintf(stdout, "/font /%s def\n", fontname);
break;
case 'm': /* magnification */
fprintf(stdout, "/magnification %s def\n", optarg);
break;
case 'n': /* forms per page */
formsperpage = atoi(optarg);
fprintf(stdout, "%s %s\n", FORMSPERPAGE, optarg);
fprintf(stdout, "/formsperpage %s def\n", optarg);
break;
case 'o': /* output page list */
out_list(optarg);
break;
case 'p': /* landscape or portrait mode */
if ( *optarg == 'l' )
fprintf(stdout, "/landscape true def\n");
else fprintf(stdout, "/landscape false def\n");
break;
case 'w': /* line width */
fprintf(stdout, "/linewidth %s def\n", optarg);
break;
case 'x': /* shift horizontally */
fprintf(stdout, "/xoffset %s def\n", optarg);
break;
case 'y': /* and vertically on the page */
fprintf(stdout, "/yoffset %s def\n", optarg);
break;
case 'A': /* force job accounting */
case 'J':
if ( (fp_acct = fopen(optarg, "a")) == NULL )
error(FATAL, "can't open accounting file %s", optarg);
break;
case 'C': /* copy file straight to output */
if ( cat(optarg) == FALSE )
error(FATAL, "can't read %s", optarg);
break;
case 'E': /* text font encoding */
fontencoding = optarg;
break;
case 'L': /* Postscript prologue file */
prologue = optarg;
break;
case 'P': /* PostScript pass through */
fprintf(stdout, "%s\n", optarg);
break;
case 'R': /* special global or page level request */
saverequest(optarg);
break;
case 'D': /* debug flag */
debug = ON;
break;
case 'I': /* ignore FATAL errors */
ignore = ON;
break;
case '?': /* don't know the option */
error(FATAL, "");
break;
default: /* don't know what to do for ch */
error(FATAL, "missing case for option %c", ch);
break;
} /* End switch */
} /* End while */
argc -= optind; /* get ready for non-option args */
argv += optind;
} /* End of options */
/*****************************************************************************/
char *get_font(name)
char *name; /* name the user asked for */
{
int i; /* for looking through fontmap[] */
/*
*
* Called from options() to map a user's font name into a legal PostScript name.
* If the lookup fails *name is returned to the caller. That should let you choose
* any PostScript font.
*
*/
for ( i = 0; fontmap[i].name != NULL; i++ )
if ( strcmp(name, fontmap[i].name) == 0 )
return(fontmap[i].val);
return(name);
} /* End of get_font */
/*****************************************************************************/
setup()
{
/*
*
* Handles things that must be done after the options are read but before the
* input files are processed.
*
*/
writerequest(0, stdout); /* global requests eg. manual feed */
setencoding(fontencoding);
fprintf(stdout, "setup\n");
if ( formsperpage > 1 ) {
if ( cat(formfile) == FALSE )
error(FATAL, "can't read %s", formfile);
fprintf(stdout, "%d setupforms\n", formsperpage);
} /* End if */
fprintf(stdout, "%s", ENDSETUP);
} /* End of setup */
/*****************************************************************************/
arguments()
{
/*
*
* Makes sure all the non-option command line options are processed. If we get
* here and there aren't any arguments left, or if '-' is one of the input files
* we'll process stdin.
*
*/
if ( argc < 1 )
conv();
else
while ( argc > 0 ) {
if ( strcmp(*argv, "-") == 0 )
fp_in = stdin;
else if ( (fp_in = fopen(*argv, "r")) == NULL )
error(FATAL, "can't open %s", *argv);
conv();
if ( fp_in != stdin )
fclose(fp_in);
argc--;
argv++;
} /* End while */
} /* End of arguments */
/*****************************************************************************/
done()
{
/*
*
* Finished with the last input file, so mark the end of the pages, make sure the
* last page is printed, and restore the initial environment.
*
*/
fprintf(stdout, "%s", TRAILER);
fprintf(stdout, "done\n");
fprintf(stdout, "%s %s\n", DOCUMENTFONTS, fontname);
fprintf(stdout, "%s %d\n", PAGES, printed);
} /* End of done */
/*****************************************************************************/
account()
{
/*
*
* Writes an accounting record to *fp_acct, provided it's not NULL.
*
*/
if ( fp_acct != NULL )
fprintf(fp_acct, " print %d\n copies %d\n", printed, copies);
} /* End of account */
/*****************************************************************************/
conv()
{
int ch; /* next input character */
/*
*
* Controls the conversion of BGI files into PostScript. Not everything has been
* implemented, but what's been done should be good enough for our purposes.
*
*/
redirect(-1); /* get ready for the first page */
bgimode = 0;
formfeed();
while ( (ch = get_char()) != EOF ) {
switch ( ch ) {
case BRCHAR: /* rotated character mode */
bgimode = ch;
text(90);
break;
case BCHAR: /* graphical character mode */
bgimode = ch;
text(0);
break;
case BGRAPH: /* graphical master mode */
bgimode = ch;
break;
case BSUB: /* subroutine definition */
subr_def();
break;
case BRET: /* end of subroutine */
subr_end();
break;
case BCALL: /* subroutine call */
subr_call();
break;
case BEND: /* end display - page */
formfeed();
break;
case BERASE: /* erase - shouldn't be used */
error(FATAL, "BGI erase opcode obsolete");
break;
case BREP: /* repeat */
error(FATAL, "Repeat not implemented");
repeat();
break;
case BSETX: /* new x coordinate */
hgoto(get_int(0));
break;
case BSETY: /* new y coordinate */
vgoto(get_int(0));
break;
case BSETXY: /* new x and y coordinates */
hgoto(get_int(0));
vgoto(get_int(0));
break;
case BINTEN: /* mark the current point */
fprintf(fp_out, "%d %d p\n", hpos, vpos);
break;
case BVISX: /* visible x */
vector(X_COORD, VISIBLE);
break;
case BINVISX: /* invisible x */
vector(X_COORD, INVISIBLE);
break;
case BVISY: /* visible y */
vector(Y_COORD, VISIBLE);
break;
case BINVISY: /* invisible y */
vector(Y_COORD, INVISIBLE);
break;
case BVEC: /* arbitrary vector */
vector(LONGVECTOR, VISIBLE);
break;
case BSVEC: /* short vector */
vector(SHORTVECTOR, VISIBLE);
break;
case BRECT: /* draw rectangle */
rectangle(OUTLINE);
break;
case BPOINT1: /* point plot 1 */
case BPOINT: /* point plot 2 */
point_plot(ch, get_char());
break;
case BLINE: /* line plot */
line_plot();
break;
case BLTY: /* line type */
fprintf(fp_out, "%s l\n", styles[get_data()]);
break;
case BARC: /* circular arc */
arc(OUTLINE);
break;
case BFARC: /* filled circle */
arc(FILL);
break;
case BFRECT: /* filled rectangle */
rectangle(FILL);
break;
case BRASRECT: /* raster rectangle */
error(FATAL, "Raster Rectangle not implemented");
break;
case BCOL: /* select color */
set_color(get_data());
break;
case BFTRAPH: /* filled trapezoid */
trapezoid();
break;
case BPAT: /* pattern for area filling */
pattern();
break;
case BCSZ: /* change BGI character 'size' */
setsize(get_data());
break;
case BNOISE: /* from bad file format */
break;
default: /* don't recognize the code */
error(FATAL, "bad BGI command %d (0%o)", ch, ch);
break;
} /* End switch */
if ( debug == ON )
fprintf(stderr, "\n");
} /* End while */
formfeed(); /* in case BEND was missing */
} /* End of conv */
/*****************************************************************************/
hgoto(n)
int n; /* new horizontal position */
{
/*
*
* Sets the current BGI horizontal position to n.
*
*/
hpos = n;
} /* End of hgoto */
/*****************************************************************************/
vgoto(n)
int n; /* move to this vertical position */
{
/*
*
* Sets the absolute vertical position to n.
*
*/
vpos = n;
} /* End of vgoto */
/*****************************************************************************/
setsize(n)
int n; /* BGI size - just a grid separation */
{
/*
*
* Called when we're supposed to change the BGI character size to n. The BGI
* size is the grid separation in a 5 by 7 array in which characters are assumed
* to be built.
*
*/
bgisize = n;
linespace = LINESPACE(bgisize);
fprintf(fp_out, "%d f\n", bgisize);
if ( debug == ON )
fprintf(stderr, "BGI size = %d\n", n);
} /* End of setsize */
/*****************************************************************************/
repeat()
{
int count; /* repeat this many times */
int ch; /* next input character */
/*
*
* Haven't implemented repeats, although it wouldn't be difficult. Apparently it's
* not used by any graphics packages that generate BGI.
*
*/
count = get_int(); /* get the repeat count */
while ( (ch = get_char()) != EOF && ch != BENDR ) ;
} /* End of repeat */
/*****************************************************************************/
text(angle)
int angle; /* either 0 or 90 degrees */
{
int ch; /* next character from file *fp_in */
/*
*
* Called from conv() after we've entered one of the graphical character modes.
* Characters are read from the input file and printed until the next mode change
* opcode is found (or until EOF). angle will be 90 for rotated character mode
* and 0 otherwise.
*
*
*/
fprintf(fp_out, "%d %d %d(", angle, hpos, vpos);
while ( (ch = get_char()) != EOF ) {
if ( ch == BGRAPH || ch == BCHAR || ch == BRCHAR ) {
ungetc(ch, fp_in);
position--;
break;
} /* End if */
switch ( ch ) {
case '\012':
vgoto(vpos - linespace);
case '\015':
hgoto(0);
fprintf(fp_out, ")t\n%d %d %d(", angle, hpos, vpos);
break;
case '(':
case ')':
case '\\':
putc('\\', fp_out);
default:
if ( isascii(ch) && isprint(ch) )
putc(ch, fp_out);
else fprintf(fp_out, "\\%.3o", ch & 0377);
break;
} /* End switch */
} /* End while */
fprintf(fp_out, ") t\n");
} /* End of text */
/*****************************************************************************/
formfeed()
{
int ch; /* repeat count for this page */
/*
*
* Does whatever is needed to print the last page and get ready for the next one.
* It's called, from conv(), after a BEND code is processed. I'm ignoring the
* copy count that's expected to follow each page.
*
*/
if ( bgimode == BGRAPH && (ch = get_char()) != EOF && ! (ch & MSB) ) {
ungetc(ch, fp_in);
position--;
} /* End if */
if ( fp_out == stdout ) /* count the last page */
printed++;
fprintf(fp_out, "cleartomark\n");
fprintf(fp_out, "showpage\n");
fprintf(fp_out, "saveobj restore\n");
fprintf(fp_out, "%s %d %d\n", ENDPAGE, page, printed);
while ( (ch = get_char()) == 0 ) ; /* skip any NULL characters */
ungetc(ch, fp_in);
position--;
if ( ungetc(getc(fp_in), fp_in) == EOF )
redirect(-1);
else redirect(++page);
fprintf(fp_out, "%s %d %d\n", PAGE, page, printed+1);
fprintf(fp_out, "/saveobj save def\n");
fprintf(fp_out, "mark\n");
writerequest(printed+1, fp_out);
fprintf(fp_out, "%d pagesetup\n", printed+1);
setsize(bgisize);
hpos = vpos = 0;
} /* End of formfeed */
/*****************************************************************************/
subr_def()
{
/*
*
* Starts a subroutine definition. All subroutines are defined as PostScript
* procedures that begin with the character S and end with the subroutine's id
* (a number between 0 and 63 - I guess). The primary, and perhaps only use of
* subroutines is in special color plots produced by several graphics libraries,
* and even there it's not all that common. I've also chosen not to worry about
* nested subroutine definitions - that would certainly be overkill!
*
* All subroutines set up their own (translated) coordinate system, do their work
* in that system, and restore things when they exit. To make everything work
* properly we save the current point (in shpos and svpos), set our position to
* (0, 0), and restore things at the end of the subroutine definition. That means
* hpos and vpos measure the relative displacement after a subroutine returns, and
* we save those values in the displacement[] array. The displacements are used
* (in subr_call()) to properly adjust our position after each subroutine call,
* and all subroutines are called with the current x and y coordinates on top of
* the stack.
*
*/
if ( in_subr == TRUE ) /* a nested subroutine definition?? */
error(FATAL, "can't handle nested subroutine definitions");
if ( (subr_id = get_data()) == EOF )
error(FATAL, "missing subroutine identifier");
if ( in_global == FALSE ) { /* just used to reduce file size some */
fprintf(fp_out, "cleartomark\n");
fprintf(fp_out, "saveobj restore\n");
fprintf(fp_out, "%s", BEGINGLOBAL);
in_global = TRUE;
} /* End if */
fprintf(fp_out, "/S%d {\n", subr_id);
fprintf(fp_out, "gsave translate\n");
shpos = hpos; /* save our current position */
svpos = vpos;
hgoto(0); /* start at the origin */
vgoto(0);
in_subr = TRUE; /* in a subroutine definition */
} /* End of subr_def */
/*****************************************************************************/
subr_end()
{
int ch; /* for looking at next opcode */
/*
*
* Handles stuff needed at the end of each subroutine. Want to remember the change
* in horizontal and vertical positions for each subroutine so we can adjust our
* position after each call - just in case. The current position was set to (0, 0)
* before we started the subroutine definition, so when we get here hpos and vpos
* are the relative displacements after the subroutine is called. They're saved in
* the displacement[] array and used to adjust the current position when we return
* from a subroutine.
*
*/
if ( in_subr == FALSE ) /* not in a subroutine definition?? */
error(FATAL, "subroutine end without corresponding start");
fprintf(fp_out, "grestore\n");
fprintf(fp_out, "} def\n");
if ( in_global == TRUE && (ch = get_char()) != BSUB ) {
fprintf(fp_out, "%s", ENDGLOBAL);
fprintf(fp_out, "/saveobj save def\n");
fprintf(fp_out, "mark\n");
in_global = FALSE;
} /* End if */
ungetc(ch, fp_in); /* put back the next opcode */
displacement[subr_id].dx = hpos;
displacement[subr_id].dy = vpos;
hgoto(shpos); /* back to where we started */
vgoto(svpos);
in_subr = FALSE; /* done with the definition */
} /* End of subr_end */
/*****************************************************************************/
subr_call()
{
int ch; /* next byte from *fp_in */
int id; /* subroutine id if ch wasn't an opcode */
/*
*
* Handles subroutine calls. Everything that follows the BCALL opcode (up to the
* next opcode) is taken as a subroutine identifier - thus the loop that generates
* the subroutine calls.
*
*/
while ( (ch = get_char()) != EOF && (ch & MSB) ) {
id = ch & DMASK;
fprintf(fp_out, "%d %d S%d\n", hpos, vpos, id);
hgoto(hpos + displacement[id].dx); /* adjust our position */
vgoto(vpos + displacement[id].dy);
} /* End while */
ungetc(ch, fp_in);
} /* End of subr_call */
/*****************************************************************************/
vector(var, mode)
int var; /* coordinate that varies next? */
int mode; /* VISIBLE or INVISIBLE vectors */
{
int ch; /* next character from *fp_in */
int x, y; /* line drawn to this point */
int count = 0; /* number of points so far */
/*
*
* Handles plotting of all types of BGI vectors. If it's a manhattan vector var
* specifies which coordinate will be changed by the next number in the input
* file.
*
*/
x = hpos; /* set up the first point */
y = vpos;
while ( (ch = get_char()) != EOF && ch & MSB ) {
if ( var == X_COORD ) /* next length is change in x */
x += get_int(ch);
else if ( var == Y_COORD ) /* it's the change in y */
y += get_int(ch);
else if ( var == LONGVECTOR ) { /* long vector */
x += get_int(ch);
y += get_int(0);
} else { /* must be a short vector */
x += ((ch & MSBMAG) * ((ch & SGNB) ? -1 : 1));
y += (((ch = get_data()) & MSBMAG) * ((ch & SGNB) ? -1 : 1));
} /* End else */
if ( mode == VISIBLE ) { /* draw the line segment */
fprintf(fp_out, "%d %d\n", hpos - x, vpos - y);
count++;
} /* End if */
hgoto(x); /* adjust the current BGI position */
vgoto(y);
if ( var == X_COORD ) /* vertical length comes next */
var = Y_COORD;
else if ( var == Y_COORD ) /* change horizontal next */
var = X_COORD;
} /* End while */
if ( count > 0 )
fprintf(fp_out, "%d %d v\n", hpos, vpos);
ungetc(ch, fp_in); /* it wasn't part of the vector */
position--;
} /* End of vector */
/*****************************************************************************/
rectangle(mode)
int mode; /* FILL or OUTLINE the rectangle */
{
int deltax; /* displacement for horizontal side */
int deltay; /* same but for vertical sides */
/*
*
* Draws a rectangle and either outlines or fills it, depending on the value of
* mode. Would be clearer, and perhaps better, if {stroke} or {fill} were put on
* the stack instead of 0 or 1. R could then define the path and just do an exec
* to fill or stroke it.
*
*/
deltax = get_int(0); /* get the height and width */
deltay = get_int(0);
if ( mode == OUTLINE )
fprintf(fp_out, "0 %d %d %d %d R\n", deltax, deltay, hpos, vpos);
else fprintf(fp_out, "1 %d %d %d %d R\n", deltax, deltay, hpos, vpos);
} /* End of rectangle */
/*****************************************************************************/
trapezoid()
{
int kind; /* which sides are parallel */
int d[6]; /* true displacements - depends on kind */
/*
*
* Handles filled trapeziods. A data byte of 0101 following the opcode means the
* horizontal sides are parallel, 0102 means the vertical sides are parallel.
* Filling is handled by eofill so we don't need to get things in the right order.
*
*/
kind = get_data();
d[0] = get_int(0);
d[1] = 0;
d[2] = get_int(0);
d[3] = get_int(0);
d[4] = get_int(0);
d[5] = 0;
if ( kind == 2 ) { /* parallel sides are vertical */
d[1] = d[0];
d[0] = 0;
d[5] = d[4];
d[4] = 0;
} /* End if */
fprintf(fp_out, "%d %d %d %d %d %d %d %d T\n", d[4], d[5], d[2], d[3], d[0], d[1], hpos, vpos);
} /* End of trapezoid */
/*****************************************************************************/
point_plot(mode, ch)
int mode; /* plotting mode BPOINT or BPOINT1 */
int ch; /* will be placed at the points */
{
int c; /* next character from input file */
int x, y; /* ch gets put here next */
int deltax; /* x increment for BPOINT1 mode */
/*
*
* The two point plot modes are used to place a character at selected points. The
* difference in the two modes, namely BPOINT and BPOINT1, is the way we get the
* coordinates of the next point. In BPOINT1 the two bytes immediately following
* ch select a constant horizontal change, while both coordinates are given for
* all points in BPOINT mode.
*
*/
if ( mode == BPOINT1 ) { /* first integer is change in x */
deltax = get_int(0);
x = hpos - deltax;
} /* End if */
while ( (c = get_char()) != EOF && (c & MSB) ) {
if ( mode == BPOINT1 ) { /* only read y coordinate */
y = get_int(c);
x += deltax;
} else { /* get new x and y from input file */
x = get_int(c);
y = get_int(0);
} /* End else */
hgoto(x); /* adjust BGI position */
vgoto(y);
fprintf(fp_out, "%d %d\n", hpos, vpos);
} /* End while */
putc('(', fp_out);
switch ( ch ) {
case '(':
case ')':
case '\\':
putc('\\', fp_out);
default:
putc(ch, fp_out);
} /* End switch */
fprintf(fp_out, ")pp\n");
ungetc(c, fp_in); /* it wasn't part of the point plot */
position--;
} /* End of point_plot */
/*****************************************************************************/
line_plot()
{
int c; /* next input character from fp_in */
int deltax; /* change in x coordinate */
int x0, y0; /* starting point for next segment */
int x1, y1; /* endpoint of the line */
int count = 0; /* number of points so far */
/*
*
* Essentially the same format as BPOINT1, except that in this case we connect
* pairs of points by line segments.
*
*/
deltax = get_int(0); /* again the change in x is first */
x1 = hpos; /* so it works first time through */
y1 = get_int(0);
while ( (c = get_char()) != EOF && (c & MSB) ) {
x0 = x1; /* line starts here */
y0 = y1;
x1 += deltax; /* and ends at this point */
y1 = get_int(c);
fprintf(fp_out, "%d %d\n", -deltax, y0 - y1);
count++;
} /* End while */
hgoto(x1); /* adjust current BGI position */
vgoto(y1);
if ( count > 0 )
fprintf(fp_out, "%d %d v\n", hpos, vpos);
ungetc(c, fp_in); /* wasn't part of the line */
position--;
} /* End of line_plot */
/*****************************************************************************/
arc(mode)
int mode; /* FILL or OUTLINE the path */
{
int dx1, dy1; /* displacements for first point */
int dx2, dy2; /* same for the second point */
int radius; /* of the arc */
int angle1, angle2; /* starting and ending angles */
/*
*
* Called whenever we need to draw an arc. I'm ignoring filled slices for now.
*
*/
dx1 = get_int(0); /* displacements relative to center */
dy1 = get_int(0);
dx2 = get_int(0);
dy2 = get_int(0);
radius = get_int(0); /* and the radius */
if ( radius == 0 ) /* nothing to do */
return;
angle1 = (atan2((double) dy1, (double) dx1) * 360) / (2 * PI) + .5;
angle2 = (atan2((double) dy2, (double) dx2) * 360) / (2 * PI) + .5;
fprintf(fp_out, "%d %d %d %d %d arcn stroke\n", hpos, vpos, radius, angle1, angle2);
} /* End of arc */
/*****************************************************************************/
pattern()
{
double red = 0; /* color components */
double green = 0;
double blue = 0;
int kind; /* corse or fine pattern */
int val; /* next color data byte */
int i; /* loop index */
/*
*
* Handles patterns by setting the current color based of the values assigned to
* the next four data bytes. BGI supports two kinds of patterns (fine or coarse)
* but I'm handling each in the same way - for now. In a fine pattern the four
* data bytes assign a color to four individual pixels (upperleft first) while
* in a coarse pattern the four colors are assigned to groups of four pixels,
* for a total of 16. Again the first color goes to the group in the upper left
* corner. The byte immediately following the BPAT opcode selects fine (040) or
* coarse (041) patterns. The PostScript RGB color is assigned by averaging the
* RED, GREEN, and BLUE components assigned to the four pixels (or groups of
* pixels). Acceptable results, but there's no distinction between fine and
* coarse patterns.
*
*/
if ( (kind = get_char()) == EOF )
error(FATAL, "bad pattern command");
for ( i = 0; i < 4; i++ ) {
val = get_data();
red += get_color(val, RED);
green += get_color(val, GREEN);
blue += get_color(val, BLUE);
} /* End for */
fprintf(fp_out, "%g %g %g c\n", red/4, green/4, blue/4);
} /* End of pattern */
/*****************************************************************************/
get_color(val, component)
int val; /* color data byte */
int component; /* RED, GREEN, or BLUE component */
{
int primary; /* color mixing mode - bits 2 to 4 */
int plane; /* primary color plane - bits 5 to 7 */
unsigned rgbcolor; /* PostScript expects an RGB triple */
/*
*
* Picks the requested color component (RED, GREEN, or BLUE) from val and returns
* the result to the caller. BGI works with Cyan, Yellow, and Magenta so the one's
* complement stuff (following the exclusive or'ing) recovers the RED, BLUE, and
* GREEN components that PostScript's setrgbcolor operator needs. The PostScript
* interpreter in the ColorScript 100 has a setcmycolor operator, but it's not
* generally available so I've decided to stick with setrgbcolor.
*
*/
primary = (val >> 3) & 07;
plane = val & 07;
rgbcolor = (~(primary ^ plane)) & 07;
if ( debug == ON )
fprintf(stderr, "val = %o, primary = %o, plane = %o, rgbcolor = %o\n",
val, primary, plane, rgbcolor);
switch ( component ) {
case RED:
return(rgbcolor>>2);
case GREEN:
return(rgbcolor&01);
case BLUE:
return((rgbcolor>>1)&01);
default:
error(FATAL, "unknown color component");
return(0);
} /* End switch */
} /* End of get_color */
/*****************************************************************************/
set_color(val)
int val; /* color data byte */
{
/*
*
* Arranges to have the color set to the value requested in the BGI data byte val.
*
*/
fprintf(fp_out, "%d %d %d c\n", get_color(val, RED), get_color(val, GREEN), get_color(val, BLUE));
} /* End of set_color */
/*****************************************************************************/
get_int(highbyte)
int highbyte; /* already read this byte */
{
int lowbyte; /* this and highbyte make the int */
/*
*
* Figures out the value on the integer (sign magnitude form) that's next in the
* input file. If highbyte is nonzero we'll use it and the next byte to build the
* integer, otherwise two bytes are read from fp_in.
*
*/
if ( highbyte == 0 ) /* need to read the first byte */
highbyte = get_data();
lowbyte = get_data(); /* always need the second byte */
return(highbyte & SGNB ? -MAG(highbyte, lowbyte) : MAG(highbyte, lowbyte));
} /* End of get_int */
/*****************************************************************************/
get_data()
{
int val; /* data value returned to caller */
/*
*
* Called when we expect to find a single data character in the input file. The
* data bit is turned off and the resulting value is returned to the caller.
*
*/
if ( (val = get_char()) == EOF || ! (val & MSB) )
error(FATAL, "missing data value");
return(val & DMASK);
} /* End of get_data */
/*****************************************************************************/
get_char()
{
int ch; /* character we just read */
/*
*
* Reads the next character from file *fp_in and returns the value to the caller.
* This routine isn't really needed, but we may want to deal directly with some
* screwball file formats so I thought it would probably be a good idea to isolate
* all the input in one routine that could be easily changed.
*
*/
if ( (ch = getc(fp_in)) != EOF ) {
position++;
ch &= CHMASK;
} /* End if */
if ( debug == ON )
fprintf(stderr, "%o ", ch);
return(ch);
} /* End of get_char */
/*****************************************************************************/
redirect(pg)
int pg; /* next page we're printing */
{
static FILE *fp_null = NULL; /* if output is turned off */
/*
*
* If we're not supposed to print page pg, fp_out will be directed to /dev/null,
* otherwise output goes to stdout.
*
*/
if ( pg >= 0 && in_olist(pg) == ON )
fp_out = stdout;
else if ( (fp_out = fp_null) == NULL )
fp_out = fp_null = fopen("/dev/null", "w");
} /* End of redirect */
/*****************************************************************************/