From 89996944e98eb69e7b1683e3fce56797688d82c7 Mon Sep 17 00:00:00 2001
From: Ralph Campbell <ralph@ucbvax.Berkeley.EDU>
Date: Thu, 10 Nov 1983 22:12:33 -0800
Subject: [PATCH] date and time created 83/11/10 14:12:33 by ralph

SCCS-vsn: lib/libplot/hp2648/circle.c 4.1
---
 usr/src/lib/libplot/hp2648/circle.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 usr/src/lib/libplot/hp2648/circle.c

diff --git a/usr/src/lib/libplot/hp2648/circle.c b/usr/src/lib/libplot/hp2648/circle.c
new file mode 100644
index 0000000000..702361198d
--- /dev/null
+++ b/usr/src/lib/libplot/hp2648/circle.c
@@ -0,0 +1,27 @@
+#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));
+}
-- 
2.20.1