HeadwayGTU.java

package org.opentrafficsim.core.gtu.following;

import org.opentrafficsim.core.gtu.lane.LaneBasedGTU;
import org.opentrafficsim.core.unit.LengthUnit;
import org.opentrafficsim.core.value.vdouble.scalar.DoubleScalar;

/**
 * Storage for a reference to a LaneBasedGTU and a headway.
 * <p>
 * Copyright (c) 2013-2014 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights
 * reserved. <br>
 * BSD-style license. See <a href="http://opentrafficsim.org/node/13">OpenTrafficSim License</a>.
 * <p>
 * @version 11 feb. 2015 <br>
 * @author <a href="http://www.tbm.tudelft.nl/averbraeck">Alexander Verbraeck</a>
 * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
 */
public class HeadwayGTU
{
    /** the other GTU. */
    private final LaneBasedGTU<?> otherGTU;

    /** the distance to the GTU in meters. */
    private final double distanceSI;

    /**
     * Construct a new HeadwayGTU.
     * @param otherGTU the other GTU
     * @param distanceSI the distance to the other GTU in meters; if the other GTU is parallel, use distance Double.NaN
     */
    public HeadwayGTU(final LaneBasedGTU<?> otherGTU, final double distanceSI)
    {
        this.otherGTU = otherGTU;
        this.distanceSI = distanceSI;
    }

    /**
     * @return the other GTU.
     */
    public final LaneBasedGTU<?> getOtherGTU()
    {
        return this.otherGTU;
    }

    /**
     * Retrieve the distance to the other GTU in meters.
     * @return the distance to the other GTU in SI unit for length (meter), the value Double.NaN is used to indicate
     *         that the other GTU is parallel with the reference GTU
     */
    public final double getDistanceSI()
    {
        return this.distanceSI;
    }

    /**
     * Retrieve the strongly typed distance to the other GTU.
     * @return DoubleScalar.Rel&lt;LengthUnit&gt;; the distance to the GTU, return value null indicates that the other
     *         GTU is parallel to the reference GTU
     */
    public final DoubleScalar.Rel<LengthUnit> getDistance()
    {
        if (Double.isNaN(this.distanceSI))
        {
            return null;
        }
        return new DoubleScalar.Rel<LengthUnit>(this.distanceSI, LengthUnit.SI);
    }
    
    /** {@inheritDoc} */
    public final String toString()
    {
        return String.format("Headway %s to %s", getDistance(), this.otherGTU);
    }

}