v_subtract_vv.java

来自「TeamBots 是一个可移植的多代理机器人仿真器」· Java 代码 · 共 77 行

/*
 * v_Subtract_vv.java
 */

package EDU.gatech.cc.is.clay;

import java.lang.*;
import EDU.gatech.cc.is.util.Vec2;
import EDU.gatech.cc.is.util.Units;

/**
 * Subtract the vector output of two embedded NodeVec2s.
 * <P>
 * For detailed information on how to configure behaviors, see the
 * <A HREF="../clay/docs/index.html">Clay page</A>.
 * <P>
 * <A HREF="../COPYRIGHT.html">Copyright</A>
 * (c)1997, 1998 Tucker Balch
 *
 * @author Tucker Balch
 * @version $Revision: 1.1 $
 */


public class v_Subtract_vv extends NodeVec2
	{
	/**
	Turn debugging on or off.
	*/
	public static final boolean DEBUG = Node.DEBUG;
	private NodeVec2	embedded1;
	private NodeVec2	embedded2;
	private double		sphere = 1.0;
	private double	        safety = 0.0;

	/**
	Instantiate a v_Subtract_vv schema. It will 
	compute im1-im2.
	@param im1 NodeVec2, the embedded node that generates a vector
			to be subtracted from.
	@param im2 NodeVec2, the embedded node that generates a vector
			subtracted from im1.
	*/
	public v_Subtract_vv(NodeVec2 im1, NodeVec2 im2)
		{
		if (DEBUG) System.out.println("v_Subtract_vv: instantiated.");
		embedded1 = im1;
		embedded2 = im2;
		}


	Vec2	last_val = new Vec2();
	long	lasttime = 0;
	/**
	Return a Vec2 representing the difference.
	@param timestamp long, only get new information if timestamp > than last call
                or timestamp == -1.
	@return the vector difference.
	*/
	public Vec2 Value(long timestamp)
		{
                if (DEBUG) System.out.println("v_Subtract_vv: Value()");
 
                if ((timestamp > lasttime)||(timestamp == -1))
                        {
                        /*--- reset the timestamp ---*/
                        if (timestamp > 0) lasttime = timestamp;
 
                        /*--- compute the difference ---*/
                        last_val = embedded1.Value(timestamp);
			last_val.sub(embedded2.Value(timestamp));
                        }

		return (new Vec2(last_val.x, last_val.y));
		}
        }