45 lines
992 B
C
Executable File
45 lines
992 B
C
Executable File
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
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/* All Rights Reserved */
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/* THIS IS UNPUBLISHED PROPRIETARY SOURCE CODE OF AT&T */
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/* The copyright notice above does not evidence any */
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/* actual or intended publication of such source code. */
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#ident "@(#)circle.c 1.1 90/08/19 SMI" /* SVr4.0 1.1 */
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/*
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* Copyright (c) 1980 Regents of the University of California.
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* All rights reserved. The Berkeley software License Agreement
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* specifies the terms and conditions for redistribution.
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*/
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/*
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* Copyright (c) 1983, 1984 1985, 1986, 1987, 1988, Sun Microsystems, Inc.
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* All Rights Reserved.
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*/
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#include "hp2648.h"
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circle (xc,yc,r)
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int xc,yc,r;
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{
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double costheta,sintheta,x,y,xn;
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int xi,yi;
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if(r<1){
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point(xc,yc);
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return;
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}
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sintheta = 1.0/r;
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costheta = pow(1-sintheta*sintheta,0.5);
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xi = x = r;
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yi = y = 0;
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do {
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point(xc+xi,yc+yi);
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xn = x;
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xi = x = x*costheta + y*sintheta;
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yi = y = y*costheta - xn*sintheta;
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} while( ! (yi==0 && xi >= r-1));
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}
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