keynodelookupaction.java

java 3d game jme 工程开发源代码

/*
 * Copyright (c) 2003-2009 jMonkeyEngine
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors 
 *   may be used to endorse or promote products derived from this software 
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
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 */

package com.jme.input.action;

import com.jme.math.Matrix3f;
import com.jme.math.Vector3f;
import com.jme.scene.Spatial;

/**
 * <code>KeyNodeLookUpAction</code> defines an action to tilt the node towards
 * the worlds positive y-axis. The rotation is along the node's left vector (the
 * first column of it's rotation matrix).
 * 
 * @author Mark Powell
 * @version $Id: KeyNodeLookUpAction.java,v 1.16 2006/09/29 22:30:18 nca Exp $
 */
public class KeyNodeLookUpAction extends KeyInputAction {
    //temporary variables to handle rotation
    private static final Matrix3f incr = new Matrix3f();

    private static final Matrix3f tempMa = new Matrix3f();

    private static final Matrix3f tempMb = new Matrix3f();

    private static final Vector3f tempVa = new Vector3f();
    //the node to manipulate
    private Spatial node;

    /**
     * Constructor instatiates a new <code>KeyNodeLookUpAction</code> object
     * using the supplied node and speed for it's attributes.
     * 
     * @param node
     *            the node that will be affected by this action.
     * @param speed
     *            the speed at which the node can move.
     */
    public KeyNodeLookUpAction(Spatial node, float speed) {
        this.node = node;
        this.speed = speed;
    }

    /**
     * <code>performAction</code> rotates the node towards the world's
     * positive y-axis at a speed of movement speed * time. Where time is the
     * time between frames and 1 corresponds to 1 second.
     * 
     * @see com.jme.input.action.KeyInputAction#performAction(InputActionEvent)
     */
    public void performAction(InputActionEvent evt) {
        node.getLocalRotation().getRotationColumn(0, tempVa);
        tempVa.normalizeLocal();
        incr.fromAngleNormalAxis(-speed * evt.getTime(), tempVa);
        node.getLocalRotation().fromRotationMatrix(
                incr.mult(node.getLocalRotation().toRotationMatrix(tempMa),
                        tempMb));
        node.getLocalRotation().normalize();
    }
}