[unix-history] / usr / src / old / vfilters / vplotf / vplotf.c

#ifndef lint
static char sccsid[] = "@(#)vplotf.c	4.3 (Berkeley) %G%";
#endif

/*
 *  Lpd filter to read standard graphics input and produce a plot on the
 *  Varian or Versatec
 */

#include <stdio.h>
#include <vfont.h>
#include <sys/vcmd.h>

#define	mapx(x)	((DevRange*((x)-botx)/del)+centx)
#define	mapy(y)	((DevRange*(del-(y)+boty)/del)-centy)
#define SOLID -1
#define DOTTED 014
#define SHORTDASHED 034
#define DOTDASHED 054
#define LONGDASHED 074

static char *Sid = "@(#)\t5/16/83";

int	linmod = SOLID;
int	done1;
char	chrtab[][16];
char	*obuf;
int	bufsize;
int	lastx;
int	lasty;
int	radius, startx, starty, endx, endy;
double	topx;
double	topy;
double	botx;
double	boty;
int	centx = 0;
int	centy = 0;
double	delx;
double	dely;
double	del;

int	warned = 0;	/* Indicates whether the warning message about
			 * unimplemented routines has been printed */

int	plotmd[] = {VPLOT};
int	prtmd[]  = {VPRINT};
int	varian;			/* 0 for versatec, 1 for varian. */
int	BYTES_PER_LINE;		/* number of bytes per raster line. */
int	PAGE_LINES;		/* number of raster lines per page. */
int	DevRange = 1536;	/* output array size (square) in pixels */
int	DevRange8 = 1536/8;	/* output array size in bytes */
int	lines;			/* number of raster lines printed */
char	zeros[880];		/* one raster line */

char	*name, *host, *acctfile;

/* variables used to print from font file */
int	fontSet = 0;		/* Has the font file been read */
struct	header header;
struct	dispatch dispatch[256];
char	*bits;
char	*fontFile = "/usr/lib/vfont/R.8";

main(argc, argv)
	int argc;
	char *argv[];
{
	register char *cp, *arg;
	register n, again;

	while (--argc) {
		if (**++argv == '-') {
			switch (argv[0][1]) {
			case 'x':
				BYTES_PER_LINE = atoi(&argv[0][2]) / 8;
				if (varian = BYTES_PER_LINE == 264) {
					DevRange = 1536;
					DevRange8 = 1536/8;
				} else {
					DevRange = 2048;
					DevRange8 = 2048/8;
				}
				break;

			case 'y':
				PAGE_LINES = atoi(&argv[0][2]);
				break;

			case 'n':
				argc--;
				name = *++argv;
				break;

			case 'h':
				argc--;
				host = *++argv;
			}
		} else
			acctfile = *argv;
	}

	/* init constants for scaling */
	topx = topy = DevRange;
	botx = boty = 0;
	delx = dely = del = DevRange;
	centx = (DevRange - mapx(topx))/2;
	centy = mapy(topy)/2;

	if ((obuf = (char *) malloc(bufsize = DevRange * DevRange8)) == NULL) {
		fprintf(stderr, "vplotf: ran out of memory\n");
		exit(2);
	}

	do {
		arg = &obuf[bufsize];
		for (cp = obuf; cp < arg; )
			*cp++ = 0;

		again = getpict();

		ioctl(1, VSETSTATE, plotmd);
		n = BYTES_PER_LINE - DevRange8;
		for (cp = obuf; cp < arg; cp += DevRange8) {
			if (write(1, cp, DevRange8) != DevRange8)
				exit(1);
			if (n && write(1, zeros, n) != n)
				exit(1);
			lines++;
		}
		ioctl(1, VSETSTATE, prtmd);
		if (varian)
			write(1, "\f", 2);
		else
			write(1, "\n\n\n\n\n", 6);
	} while (again);

	account(name, host, *argv);
	exit(0);
}

account(who, from, acctfile)
	char *who, *from, *acctfile;
{
	register FILE *a;

	if (who == NULL || acctfile == NULL)
		return;
	if (access(acctfile, 02) || (a = fopen(acctfile, "a")) == NULL)
		return;
	/*
	 * Varian accounting is done by 8.5 inch pages;
	 * Versatec accounting is by the (12 inch) foot.
	 */
	fprintf(a, "t%6.2f\t", (lines / 200.0) / PAGE_LINES);
	if (from != NULL)
		fprintf(a, "%s:", from);
	fprintf(a, "%s\n", who);
	fclose(a);
}

getpict()
{
	register x1, y1;

	for (;;) switch (x1 = getc(stdin)) {

	case '\n':
		continue;

	case 's':
		botx = getinteger(stdin);
		boty = getinteger(stdin);
		topx = getinteger(stdin);
		topy = getinteger(stdin);
		delx = topx-botx;
		dely = topy-boty;
		if (dely/delx > 1536./2048.)
			del = dely;
		else
			del = delx;
		centx = 0;
		centx = (DevRange - mapx(topx))/2;
		centy = 0;
		centy = mapy(topy) / 2;
		continue;

	case 'b':
		x1 = getc(stdin);
		continue;

	case 'l':
		done1 |= 01;
		x1 = mapx(getinteger(stdin));
		y1 = mapy(getinteger(stdin));
		lastx = mapx(getinteger(stdin));
		lasty = mapy(getinteger(stdin));
		line(x1, y1, lastx, lasty);
		continue;

	case 'c':
		x1 = mapx(getinteger(stdin));
		y1 = mapy(getinteger(stdin));
		radius = mapx(getinteger(stdin));
		circle(x1, y1, radius);
		continue;
		
	case 'a':
		x1 = mapx(getinteger(stdin));
		y1 = mapy(getinteger(stdin));
		startx = mapx(getinteger(stdin));
		starty = mapy(getinteger(stdin));
		endx = mapx(getinteger(stdin));
		endy = mapy(getinteger(stdin));
		if (!warned) {
			fprintf(stderr,"Arcs are unimplemented\n");
			warned++;
		}
		continue;

	case 'm':
		lastx = mapx(getinteger(stdin));
		lasty = mapy(getinteger(stdin));
		continue;

	case 't':
		lastx = lastx - 6;
		lasty = lasty + 6;
		done1 |= 01;
		while ((x1 = getc(stdin)) != '\n')
			plotch(x1);
		continue;

	case 'e':
		if (done1)
			return(1);
		continue;

	case 'p':
		done1 |= 01;
		lastx = mapx(getinteger(stdin));
		lasty = mapy(getinteger(stdin));
		point(lastx, lasty);
		point(lastx+1, lasty);
		point(lastx, lasty+1);
		point(lastx+1, lasty+1);
		continue;

	case 'n':
		done1 |= 01;
		x1 = mapx(getinteger(stdin));
		y1 = mapy(getinteger(stdin));
		line(lastx, lasty, x1, y1);
		lastx = x1;
		lasty = y1;
		continue;

	case 'f':
		getinteger(stdin);
		getc(stdin);
		switch (getc(stdin)) {
		case 't':
			linmod = DOTTED;
			break;
		default:
		case 'i':
			linmod = SOLID;
			break;
		case 'g':
			linmod = LONGDASHED;
			break;
		case 'r':
			linmod = SHORTDASHED;
			break;
		case 'd':
			linmod = DOTDASHED;
			break;
		}
		while ((x1 = getc(stdin)) != '\n')
			if (x1 == EOF)
				return(0);
		continue;

	case 'd':
		getinteger(stdin);
		getinteger(stdin);
		getinteger(stdin);
		x1 = getinteger(stdin);
		while (--x1 >= 0)
			getinteger(stdin);
		continue;

	case 0:		/* ignore null characters */
		continue;

	case 255:
	case EOF:
		return(0);

	default:
		fprintf(stderr, "Input format error %c(%o)\n",x1,x1);
		exit(2);
	}
}

plotch(ch)
char ch;
{
	register int i,j,k;
	register char *ptr,c;
	int nbytes;

	if (!fontSet)
		InitFont();	/* Read font if not already read */

	ptr = bits + dispatch[ch].addr;

	for (i = dispatch[ch].up; i > -dispatch[ch].down; --i) {
		nbytes = (dispatch[ch].right + dispatch[ch].left + 7)/8;
		for (j = 0; j < nbytes; j++) {
			c = *ptr++;
			for (k = 7; k >= 0; k--)
				if ((c >> k) & 1)
					point(lastx+7-k+j*8-dispatch[ch].left, lasty-i);
		}
	}
	if (ch != ' ')
		lastx += dispatch[ch].width;
	else
		lastx += dispatch['a'].width;
}

InitFont()
{
	char *s;
	int fonts;
	int i;

	fontSet = 1;
	/* Get the font file */
	s = fontFile;
	if ((fonts = open(s, 0)) == -1) {
		perror(s);
		fprintf(stderr, "Can't get font file");
		exit(2);
	}
	/* Get the header and check magic number */
	if (read(fonts, &header, sizeof(header)) != sizeof(header)) {
		perror(s);
		fprintf(stderr, "Bad read in font file");
		exit(2);
	}
	if (header.magic != 0436) {
		fprintf(stderr,"Bad magic numer in font file");
		exit(2);
	}
	/* Get dispatches */
	if (read(fonts, dispatch, sizeof(dispatch)) != sizeof(dispatch)) {
		perror(s);
		fprintf(stderr, "Bad read in font file");
		exit(2);
	}
	/* Allocate space for bit map and read in bits */
	bits = (char *) malloc(header.size);
	if (read(fonts, bits, header.size) != header.size) {
		perror(s);
		fprintf(stderr,"Can't read bit map in font file");
		exit(2);
	}
	/* Close font file */
	if (close(fonts) != 0) {
		perror(s);
		fprintf(stderr,"Can't close font file");
		exit(2);
	}
}

line(x0, y0, x1, y1)
register x0, y0;
{
	int dx, dy;
	int xinc, yinc;
	register res1;
	int res2;
	int slope;

	xinc = 1;
	yinc = 1;
	if ((dx = x1-x0) < 0) {
		xinc = -1;
		dx = -dx;
	}
	if ((dy = y1-y0) < 0) {
		yinc = -1;
		dy = -dy;
	}
	slope = xinc*yinc;
	res1 = 0;
	res2 = 0;
	if (dx >= dy) while (x0 != x1) {
		if ((x0+slope*y0) & linmod)
			point(x0, y0);
		if (res1 > res2) {
			res2 += dx - res1;
			res1 = 0;
			y0 += yinc;
		}
		res1 += dy;
		x0 += xinc;
	} else while (y0 != y1) {
		if ((x0+slope*y0) & linmod)
		point(x0, y0);
		if (res1 > res2) {
			res2 += dy - res1;
			res1 = 0;
			x0 += xinc;
		}
		res1 += dx;
		y0 += yinc;
	}
	if ((x1+slope*y1) & linmod)
		point(x1, y1);
}

#define labs(a) (a >= 0 ? a : -a)

circle(x,y,c)
{
	register dx, dy;
	long ep;
	int de;

	dx = 0;
	ep = 0;
	for (dy=c; dy>=dx; dy--) {
		for (;;) {
			point(x+dx, y+dy);
			point(x-dx, y+dy);
			point(x+dx, y-dy);
			point(x-dx, y-dy);
			point(x+dy, y+dx);
			point(x-dy, y+dx);
			point(x+dy, y-dx);
			point(x-dy, y-dx);
			ep += 2*dx + 1;
			de = -2*dy + 1;
			dx++;
			if (labs(ep) >= labs(ep+de)) {
				ep += de;
				break;
			}
		}
	}
}

/*
 * Points should be in the range 0 <= x (or y) <= DevRange.
 * The origin is the top left-hand corner with increasing x towards the
 * right and increasing y going down.
 */
point(x, y)
register unsigned x, y;
{
	register unsigned byte;

	if (x < DevRange && y < DevRange) {
		byte = y * DevRange8 + (x >> 3);
		obuf[byte] |= 1 << (7 - (x & 07));
	}
}

getinteger(f)
FILE *f;
{
	register int low, high, result;

	low = getc(f);
	high = getc(f);
	result = ((high << 8) | low);
	if (high > 127)
		result |= ~0xffff;
	return(result);
}
Commit	Line	Data
c936af6c SL	1	#ifndef lint
	2	static char sccsid[] = "@(#)vplotf.c 4.3 (Berkeley) %G%";
	3	#endif
	4
ec143a1b RC	5	/*
	6	* Lpd filter to read standard graphics input and produce a plot on the
	7	* Varian or Versatec
	8	*/
	9
	10	#include <stdio.h>
	11	#include <vfont.h>
	12	#include <sys/vcmd.h>
	13
	14	#define mapx(x) ((DevRange*((x)-botx)/del)+centx)
	15	#define mapy(y) ((DevRange*(del-(y)+boty)/del)-centy)
	16	#define SOLID -1
	17	#define DOTTED 014
	18	#define SHORTDASHED 034
	19	#define DOTDASHED 054
	20	#define LONGDASHED 074
	21
022ef3a0	22	static char *Sid = "@(#)\t5/16/83";
ec143a1b RC	23
	24	int linmod = SOLID;
	25	int done1;
	26	char chrtab[][16];
	27	char *obuf;
	28	int bufsize;
	29	int lastx;
	30	int lasty;
	31	int radius, startx, starty, endx, endy;
	32	double topx;
	33	double topy;
	34	double botx;
	35	double boty;
	36	int centx = 0;
	37	int centy = 0;
	38	double delx;
	39	double dely;
	40	double del;
	41
	42	int warned = 0; /* Indicates whether the warning message about
	43	* unimplemented routines has been printed */
	44
	45	int plotmd[] = {VPLOT};
	46	int prtmd[] = {VPRINT};
022ef3a0 RC	47	int varian; /* 0 for versatec, 1 for varian. */
	48	int BYTES_PER_LINE; /* number of bytes per raster line. */
	49	int PAGE_LINES; /* number of raster lines per page. */
ec143a1b RC	50	int DevRange = 1536; /* output array size (square) in pixels */
ec143a1b RC	51	int DevRange8 = 1536/8; /* output array size in bytes */
ec143a1b RC	52	int lines; /* number of raster lines printed */
	53	char zeros[880]; /* one raster line */
	54
	55	char name, host, *acctfile;
	56
022ef3a0	57	/* variables used to print from font file */
ec143a1b RC	58	int fontSet = 0; /* Has the font file been read */
	59	struct header header;
	60	struct dispatch dispatch[256];
	61	char *bits;
022ef3a0	62	char *fontFile = "/usr/lib/vfont/R.8";
ec143a1b RC	63
	64	main(argc, argv)
	65	int argc;
	66	char *argv[];
	67	{
	68	register char cp, arg;
	69	register n, again;
	70
ec143a1b RC	71	while (--argc) {
	72	if (**++argv == '-') {
	73	switch (argv[0][1]) {
022ef3a0 RC	74	case 'x':
	75	BYTES_PER_LINE = atoi(&argv[0][2]) / 8;
	76	if (varian = BYTES_PER_LINE == 264) {
	77	DevRange = 1536;
	78	DevRange8 = 1536/8;
	79	} else {
	80	DevRange = 2048;
	81	DevRange8 = 2048/8;
	82	}
	83	break;
	84
	85	case 'y':
	86	PAGE_LINES = atoi(&argv[0][2]);
	87	break;
	88
ec143a1b RC	89	case 'n':
	90	argc--;
	91	name = *++argv;
	92	break;
	93
	94	case 'h':
	95	argc--;
	96	host = *++argv;
	97	}
	98	} else
	99	acctfile = *argv;
	100	}
	101
	102	/* init constants for scaling */
	103	topx = topy = DevRange;
	104	botx = boty = 0;
	105	delx = dely = del = DevRange;
	106	centx = (DevRange - mapx(topx))/2;
	107	centy = mapy(topy)/2;
	108
	109	if ((obuf = (char ) malloc(bufsize = DevRange DevRange8)) == NULL) {
	110	fprintf(stderr, "vplotf: ran out of memory\n");
	111	exit(2);
	112	}
	113
	114	do {
	115	arg = &obuf[bufsize];
	116	for (cp = obuf; cp < arg; )
	117	*cp++ = 0;
	118
	119	again = getpict();
	120
	121	ioctl(1, VSETSTATE, plotmd);
022ef3a0	122	n = BYTES_PER_LINE - DevRange8;
ec143a1b RC	123	for (cp = obuf; cp < arg; cp += DevRange8) {
	124	if (write(1, cp, DevRange8) != DevRange8)
	125	exit(1);
	126	if (n && write(1, zeros, n) != n)
	127	exit(1);
	128	lines++;
	129	}
	130	ioctl(1, VSETSTATE, prtmd);
	131	if (varian)
	132	write(1, "\f", 2);
	133	else
	134	write(1, "\n\n\n\n\n", 6);
	135	} while (again);
	136
	137	account(name, host, *argv);
	138	exit(0);
	139	}
	140
	141	account(who, from, acctfile)
	142	char who, from, *acctfile;
	143	{
	144	register FILE *a;
	145
	146	if (who == NULL \|\| acctfile == NULL)
	147	return;
	148	if (access(acctfile, 02) \|\| (a = fopen(acctfile, "a")) == NULL)
	149	return;
	150	/*
	151	* Varian accounting is done by 8.5 inch pages;
	152	* Versatec accounting is by the (12 inch) foot.
	153	*/
022ef3a0	154	fprintf(a, "t%6.2f\t", (lines / 200.0) / PAGE_LINES);
ec143a1b RC	155	if (from != NULL)
	156	fprintf(a, "%s:", from);
	157	fprintf(a, "%s\n", who);
	158	fclose(a);
	159	}
	160
	161	getpict()
	162	{
	163	register x1, y1;
	164
	165	for (;;) switch (x1 = getc(stdin)) {
	166
	167	case '\n':
	168	continue;
	169
	170	case 's':
	171	botx = getinteger(stdin);
	172	boty = getinteger(stdin);
	173	topx = getinteger(stdin);
	174	topy = getinteger(stdin);
	175	delx = topx-botx;
	176	dely = topy-boty;
	177	if (dely/delx > 1536./2048.)
	178	del = dely;
	179	else
	180	del = delx;
	181	centx = 0;
	182	centx = (DevRange - mapx(topx))/2;
	183	centy = 0;
	184	centy = mapy(topy) / 2;
	185	continue;
	186
	187	case 'b':
	188	x1 = getc(stdin);
	189	continue;
	190
	191	case 'l':
	192	done1 \|= 01;
	193	x1 = mapx(getinteger(stdin));
	194	y1 = mapy(getinteger(stdin));
	195	lastx = mapx(getinteger(stdin));
	196	lasty = mapy(getinteger(stdin));
	197	line(x1, y1, lastx, lasty);
	198	continue;
	199
	200	case 'c':
	201	x1 = mapx(getinteger(stdin));
	202	y1 = mapy(getinteger(stdin));
	203	radius = mapx(getinteger(stdin));
	204	circle(x1, y1, radius);
	205	continue;
	206
	207	case 'a':
	208	x1 = mapx(getinteger(stdin));
	209	y1 = mapy(getinteger(stdin));
	210	startx = mapx(getinteger(stdin));
	211	starty = mapy(getinteger(stdin));
	212	endx = mapx(getinteger(stdin));
	213	endy = mapy(getinteger(stdin));
	214	if (!warned) {
	215	fprintf(stderr,"Arcs are unimplemented\n");
	216	warned++;
	217	}
	218	continue;
219
220	case 'm':
221	lastx = mapx(getinteger(stdin));
222	lasty = mapy(getinteger(stdin));
223	continue;
224
225	case 't':
226	lastx = lastx - 6;
227	lasty = lasty + 6;
228	done1 \|= 01;
229	while ((x1 = getc(stdin)) != '\n')
230	plotch(x1);
231	continue;
232
233	case 'e':
234	if (done1)
235	return(1);
236	continue;
237
238	case 'p':
239	done1 \|= 01;
240	lastx = mapx(getinteger(stdin));
241	lasty = mapy(getinteger(stdin));
242	point(lastx, lasty);
243	point(lastx+1, lasty);
244	point(lastx, lasty+1);
245	point(lastx+1, lasty+1);
246	continue;
247
248	case 'n':
249	done1 \|= 01;
250	x1 = mapx(getinteger(stdin));
251	y1 = mapy(getinteger(stdin));
252	line(lastx, lasty, x1, y1);
253	lastx = x1;
254	lasty = y1;
255	continue;
256
257	case 'f':
258	getinteger(stdin);
259	getc(stdin);
260	switch (getc(stdin)) {
261	case 't':
262	linmod = DOTTED;
263	break;
264	default:
265	case 'i':
266	linmod = SOLID;
267	break;
268	case 'g':
269	linmod = LONGDASHED;
270	break;
271	case 'r':
272	linmod = SHORTDASHED;
273	break;
274	case 'd':
275	linmod = DOTDASHED;
276	break;
277	}
278	while ((x1 = getc(stdin)) != '\n')
279	if (x1 == EOF)
280	return(0);
281	continue;
282
283	case 'd':
284	getinteger(stdin);
285	getinteger(stdin);
286	getinteger(stdin);
287	x1 = getinteger(stdin);
288	while (--x1 >= 0)
289	getinteger(stdin);
290	continue;
291
292	case 0: /* ignore null characters */
293	continue;
294
295	case 255:
296	case EOF:
297	return(0);
298
299	default:
300	fprintf(stderr, "Input format error %c(%o)\n",x1,x1);
301	exit(2);
302	}
303	}
304
305	plotch(ch)
306	char ch;
307	{
308	register int i,j,k;
309	register char *ptr,c;
310	int nbytes;
311
312	if (!fontSet)
313	InitFont(); /* Read font if not already read */
314
315	ptr = bits + dispatch[ch].addr;
316
317	for (i = dispatch[ch].up; i > -dispatch[ch].down; --i) {
318	nbytes = (dispatch[ch].right + dispatch[ch].left + 7)/8;
319	for (j = 0; j < nbytes; j++) {
320	c = *ptr++;
321	for (k = 7; k >= 0; k--)
322	if ((c >> k) & 1)
323	point(lastx+7-k+j*8-dispatch[ch].left, lasty-i);
324	}
325	}
326	if (ch != ' ')
327	lastx += dispatch[ch].width;
328	else
329	lastx += dispatch['a'].width;
330	}
331
332	InitFont()
333	{
334	char *s;
335	int fonts;
336	int i;
337
338	fontSet = 1;
339	/* Get the font file */
340	s = fontFile;
341	if ((fonts = open(s, 0)) == -1) {
342	perror(s);
343	fprintf(stderr, "Can't get font file");
344	exit(2);
345	}
346	/* Get the header and check magic number */
347	if (read(fonts, &header, sizeof(header)) != sizeof(header)) {
348	perror(s);
349	fprintf(stderr, "Bad read in font file");
350	exit(2);
351	}
352	if (header.magic != 0436) {
353	fprintf(stderr,"Bad magic numer in font file");
354	exit(2);
355	}
356	/* Get dispatches */
357	if (read(fonts, dispatch, sizeof(dispatch)) != sizeof(dispatch)) {
358	perror(s);
359	fprintf(stderr, "Bad read in font file");
360	exit(2);
361	}
362	/* Allocate space for bit map and read in bits */
363	bits = (char *) malloc(header.size);
364	if (read(fonts, bits, header.size) != header.size) {
365	perror(s);
366	fprintf(stderr,"Can't read bit map in font file");
367	exit(2);
368	}
369	/* Close font file */
370	if (close(fonts) != 0) {
371	perror(s);
372	fprintf(stderr,"Can't close font file");
373	exit(2);
374	}
375	}
376
377	line(x0, y0, x1, y1)
378	register x0, y0;
379	{
380	int dx, dy;
381	int xinc, yinc;
382	register res1;
383	int res2;
384	int slope;
385
386	xinc = 1;
387	yinc = 1;
388	if ((dx = x1-x0) < 0) {
389	xinc = -1;
390	dx = -dx;
391	}
392	if ((dy = y1-y0) < 0) {
393	yinc = -1;
394	dy = -dy;
395	}
396	slope = xinc*yinc;
397	res1 = 0;
398	res2 = 0;
399	if (dx >= dy) while (x0 != x1) {
400	if ((x0+slope*y0) & linmod)
401	point(x0, y0);
402	if (res1 > res2) {
403	res2 += dx - res1;
404	res1 = 0;
405	y0 += yinc;
406	}
407	res1 += dy;
408	x0 += xinc;
409	} else while (y0 != y1) {
410	if ((x0+slope*y0) & linmod)
411	point(x0, y0);
412	if (res1 > res2) {
413	res2 += dy - res1;
414	res1 = 0;
415	x0 += xinc;
416	}
417	res1 += dx;
418	y0 += yinc;
419	}
420	if ((x1+slope*y1) & linmod)
421	point(x1, y1);
422	}
423
424	#define labs(a) (a >= 0 ? a : -a)
425
426	circle(x,y,c)
427	{
428	register dx, dy;
429	long ep;
430	int de;
431
432	dx = 0;
433	ep = 0;
434	for (dy=c; dy>=dx; dy--) {
435	for (;;) {
436	point(x+dx, y+dy);
437	point(x-dx, y+dy);
438	point(x+dx, y-dy);
439	point(x-dx, y-dy);
440	point(x+dy, y+dx);
441	point(x-dy, y+dx);
442	point(x+dy, y-dx);
443	point(x-dy, y-dx);
444	ep += 2*dx + 1;
445	de = -2*dy + 1;
446	dx++;
447	if (labs(ep) >= labs(ep+de)) {
448	ep += de;
449	break;
450	}
451	}
452	}
453	}
454
455	/*
456	* Points should be in the range 0 <= x (or y) <= DevRange.
457	* The origin is the top left-hand corner with increasing x towards the
458	* right and increasing y going down.
459	*/
460	point(x, y)
461	register unsigned x, y;
462	{
463	register unsigned byte;
464
465	if (x < DevRange && y < DevRange) {
466	byte = y * DevRange8 + (x >> 3);
467	obuf[byte] \|= 1 << (7 - (x & 07));
468	}
469	}
470
471	getinteger(f)
472	FILE *f;
473	{
474	register int low, high, result;
475
476	low = getc(f);
477	high = getc(f);
478	result = ((high << 8) \| low);
479	if (high > 127)
480	result \|= ~0xffff;
481	return(result);
482	}