[unix-history] / usr / src / lib / libplot / hp2648 / circle.c

#ifndef lint
static char sccsid[] = "@(#)circle.c	4.1 (Berkeley) %G%";
#endif

#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));
}
Commit	Line	Data
89996944 RC	1	#ifndef lint
	2	static char sccsid[] = "@(#)circle.c 4.1 (Berkeley) %G%";
	3	#endif
	4
	5	#include "hp2648.h"
	6
	7	circle (xc,yc,r)
	8	int xc,yc,r;
	9	{
	10	double costheta,sintheta,x,y,xn;
	11	int xi,yi;
	12
	13	if(r<1){
	14	point(xc,yc);
	15	return;
	16	}
	17	sintheta = 1.0/r;
	18	costheta = pow(1-sintheta*sintheta,0.5);
	19	xi = x = r;
	20	yi = y = 0;
	21	do {
	22	point(xc+xi,yc+yi);
	23	xn = x;
	24	xi = x = xcostheta + ysintheta;
	25	yi = y = ycostheta - xnsintheta;
	26	} while( ! (yi==0 && xi >= r-1));
	27	}