eÿarc.c         —ô¶  0int del 20;
step(d){
	del = d;
}
arc(x,y,x0,y0,x1,y1){
	double pc;
	double sqrt();
	int flg,m,xc,yc,xs,ys,qs,qf;
	float dx,dy,r;
	char use;
	dx = x-x0;
	dy = y-y0;
	r = dx*dx+dy*dy;
	pc = r;
	pc = sqrt(pc);
	flg = pc/4;
	if(flg == 0)step(1);
	else if(flg < del)step(flg);
	xc = xs = x0;
	yc = ys = y0;
	move(xs,ys);
	if(x0 == x1 && y0 == y1)flg=0;
	else flg=1;
	qs = quad(x,y,x0,y0);
	qf = quad(x,y,x1,y1);
	if(abs(x-x1) < abs(y-y1)){
		use = 'x';
		if(qs == 2 || qs ==3)m = -1;
		else m=1;
	}
	else {
		use = 'y';
		if(qs > 2)m= -1;
		else m= 1;
	}
	while(1){
		switch(use){
		case 'x':	
			if(qs == 2 || qs == 3)yc =- del;
			else yc =+ del;
			dy = yc-y;
			pc = r-dy*dy;
			xc = m*sqrt(pc)+x;
			if((x < xs && x >= xc) || ( x > xs && x <= xc) ||
			    (y < ys && y >= yc) || ( y > ys && y <=  yc) )
			{
				if(++qs > 4)qs=1;
				if(qs == 2 || qs == 3)m= -1;
				else m=1;
				flg=1;
			}
			cont(xc,yc);
			xs = xc; 
			ys = yc;
			if(qs == qf && flg == 1)
				switch(qf){
				case 3:
				case 4:	
					if(xs >= x1)return;
					continue;
				case 1:
				case 2:
					if(xs <= x1)return;
				}
			continue;
		case 'y':	
			if(qs > 2)xc =+ del;
			else xc =- del;
			dx = xc-x;
			pc = r-dx*dx;
			yc = m*sqrt(pc)+y;
			if((x < xs && x >= xc) || ( x > xs && x <= xc ) ||
			    (y < ys && y >= yc) || (y > ys && y <= yc) )
			{
				if(++qs > 4)qs=1;
				if(qs > 2)m = -1;
				else m = 1;
				flg=1;
			}
			cont(xc,yc);
			xs = xc; 
			ys = yc;
			if(qs == qf && flg == 1)
				switch(qs){
				case 1:
				case 4:
					if(ys >= y1)return;
					continue;
				case 2:
				case 3:
					if(ys <= y1)return;
				}
		}
	}
}
quad(x,y,xp,yp){
	if(x < xp)
		if(y <= yp)return(1);
		else return(4);
	else if(x > xp)
		if(y < yp)return(2);
		else return(3);
	else if(y < yp)return(2);
	else return(4);
}
abs(a){
	if(a < 0)return(-a);
	return(a);
}
circle.c      —ô¶  ( circle(x,y,r){
	arc(x,y,x+r,y,x+r,y);
}
close.c       —ô¶  i #include <stdio.h>
closevt(){
	putch(037);
	fflush(stdout);
}
closepl(){
	putch(037);
	fflush(stdout);
}
(dot.c         —ô¶  	 dot(){
}
<erase.c       ˜ô¶  À extern int ohiy;
extern int ohix;
extern int oloy;
extern int oextra;
erase(){
	int i;
		putch(033);
		putch(014);
		ohiy= -1;
		ohix = -1;
		oextra = -1;
		oloy = -1;
		sleep(2);
		return;
}
label.c       Àô¶  J#define N 0104
#define E 0101
#define NE 0105
#define S 0110
#define W 0102
#define SW 0112
/*	arrange by incremental plotting that an initial
 *	character such as +, X, *, etc will fall
 *	right on the point, and undo it so that further
 *	labels will fall properly in place
 */
char lbl_mv[] {
	036,040,S,S,S,S,S,S,SW,SW,SW,SW,SW,SW,SW,SW,SW,SW,037,0
};
char lbl_umv[] {
	036,040,N,N,N,N,N,N,NE,NE,NE,NE,NE,NE,NE,NE,NE,NE,037,0
};
label(s)
char *s;
{
	register i,c;
	for(i=0; c=lbl_mv[i]; i++)
		putch(c);
	for(i=0; c=s[i]; i++)
		putch(c);
	for(i=0; c=lbl_umv[i]; i++)
		putch(c);
}
line.c        Âô¶  1 line(x0,y0,x1,y1){
	move(x0,y0);
	cont(x1,y1);
}
vlinemod.c     Àô¶  Ø linemod(s)
char *s;
{
	char c;
	putch(033);
	switch(s[0]){
	case 'l':	
		c = 'd';
		break;
	case 'd':	
		if(s[3] != 'd')c='a';
		else c='b';
		break;
	case 's':
		if(s[5] != '\0')c='c';
		else c='`';
	}
	putch(c);
}
move.c        Âô¶  * move(xi,yi){
	putch(035);
	cont(xi,yi);
}
open.c        Àô¶   openvt ()
{
}
openpl(){
}
point.c       Âô¶  , point(xi,yi){
	move(xi,yi);
	cont(xi,yi);
}
scale.c       Àô¶  extern float scalex;
extern float scaley;
extern int scaleflag;
scale(i,x,y)
char i;
float x,y;
{
	switch(i) {
	default:
		return;
	case 'c':
		x =* 2.54;
		y =* 2.54;
	case 'i':
		x =/ 200;
		y =/ 200;
	case 'u':
		scalex = 1/x;
		scaley = 1/y;
	}
	scaleflag = 1;
}
ispace.c       Àô¶  !extern float botx;
extern float boty;
extern float obotx;
extern float oboty;
extern float scalex;
extern float scaley;
extern int scaleflag;
space(x0,y0,x1,y1){
	botx = 0.;
	boty = 0.;
	obotx = x0;
	oboty = y0;
	if(scaleflag)
		return;
	scalex = 3120./(x1-x0);
	scaley = 3120./(y1-y0);
}
msubr.c        Zù¶  p#include <stdio.h>
float obotx 0.;
float oboty 0.;
float botx 0.;
float boty 0.;
float scalex 1.;
float scaley 1.;
int scaleflag;

int oloy -1;
int ohiy -1;
int ohix -1;
int oextra -1;
cont(x,y){
	int hix,hiy,lox,loy,extra;
	int n;
	x = (x-obotx)*scalex + botx;
	y = (y-oboty)*scaley + boty;
	hix=(x>>7) & 037;
	hiy=(y>>7) & 037;
	lox = (x>>2)&037;
	loy=(y>>2)&037;
	extra=x&03+(y<<2)&014;
	n = (abs(hix-ohix) + abs(hiy-ohiy) + 6) / 12;
	if(hiy != ohiy){
		putch(hiy|040);
		ohiy=hiy;
	}
	if(hix != ohix){
		if(extra != oextra){
			putch(extra|0140);
			oextra=extra;
		}
		putch(loy|0140);
		putch(hix|040);
		ohix=hix;
		oloy=loy;
	}
	else{
		if(extra != oextra){
			putch(extra|0140);
			putch(loy|0140);
			oextra=extra;
			oloy=loy;
		}
		else if(loy != oloy){
			putch(loy|0140);
			oloy=loy;
		}
	}
	putch(lox|0100);
	while(n--)
		putch(0);
}

putch(c){
	putc(c,stdout);
}
box.c         ÏÕ	¶  r box(x0, y0, x1, y1)
{
	move(x0, y0);
	cont(x0, y1);
	cont(x1, y1);
	cont(x1, y0);
	cont(x0, y0);
	move(x1, y1);
}