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/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
#ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.1 */
/*
* Copyright (c) 1980 Regents of the University of California.
* All rights reserved. The Berkeley software License Agreement
* specifies the terms and conditions for redistribution.
*/
/*
* Copyright (c) 1983, 1984 1985, 1986, 1987, 1988, Sun Microsystems, Inc.
* All Rights Reserved.
*/
#include "hp2648.h"
circle (xc,yc,r)
int xc,yc,r;
{
double costheta,sintheta,x,y,xn;
int xi,yi;
if(r<1){
point(xc,yc);
return;
}
sintheta = 1.0/r;
costheta = pow(1-sintheta*sintheta,0.5);
xi = x = r;
yi = y = 0;
do {
point(xc+xi,yc+yi);
xn = x;
xi = x = x*costheta + y*sintheta;
yi = y = y*costheta - xn*sintheta;
} while( ! (yi==0 && xi >= r-1));
}
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