friend.java

java编程的一些Applets例子。值得深入研究一下。

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// $Id: Friend.java,v 1.3 1996/04/16 20:55:23 greg Exp $

import java.lang.Math;
import java.awt.*;

/*

Strangely enough, a Friend is really one of the enemies that are always
shooting at your ship.  See comments in 'Figure' for more details.

*/

public class Friend extends Figure
{
    static int fs = 8;
    static int shape[][][] =
        {{{0,fs},{fs,0}},{{fs,0},{-fs,0}},{{-fs,0},{0,fs}}};
    Friend() {
	super( shape );
    }

    // Create a Friend which is placed sitting on the given line.
    static Figure onEdge( int sx, int sy, int ex, int ey ) {
	Friend f = new Friend();
	double angle = Math.atan2( sy-ey, sx-ex );
	return f.transform( (sx+ex)/2, (sy+ey)/2, angle );
    }
}