/*
 * Moonlight|3D Copyright (C) 2005 The Moonlight|3D team
 * 
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 * 
 * Created on Jan 5, 2005
 */
package ml.backend.sg;

import ml.math.AxisAlignedBoundingBox;
import ml.math.Matrix3;
import ml.math.Matrix4;
import ml.math.Vector3D;

/**
 * This class implements the root scene graph node type.
 * 
 * @author gregor
 */
public class Root extends TransformableNode {

    /* (non-Javadoc)
     * @see ml.backend.sg.Node#applyMatrix(ml.math.Matrix3)
     */
    @Override
    public void applyMatrix(Matrix3 matrix) {
        for(int i=0;i<children.size();i++) {
            if(children.get(i) instanceof TransformableNode) {
              ((TransformableNode)children.get(i)).applyMatrix(matrix);
            }
        }
    }

    /* (non-Javadoc)
     * @see ml.backend.sg.Node#applyMatrix(ml.math.Matrix4)
     */
    @Override
    public void applyMatrix(Matrix4 matrix) {
        for(int i=0;i<children.size();i++) {
            if(children.get(i) instanceof TransformableNode) {
                ((TransformableNode)children.get(i)).applyMatrix(matrix);
              }
        }
    }

    /* (non-Javadoc)
     * @see ml.backend.sg.Node#getBoundingBox()
     */
    @Override
    public AxisAlignedBoundingBox getBoundingBox() {
        AxisAlignedBoundingBox res=null;
        
        for(int i=1;i<children.size();i++) {
            if(children.get(i) instanceof TransformableNode) {
                if(res==null) {
                    res=((TransformableNode)children.get(i)).getBoundingBox();
                } else {
                    res=res.merge(((TransformableNode)children.get(i)).getBoundingBox());
                }
            }
        }
        
        return res;
    }
    
    /**
     * find the nearest intersection point among the child nodes of this node
     */
    @Override
    public Vector3D getIntersectionPoint(ml.math.Ray ray)
    {
        Vector3D intersection=null;
        double distance=0;
        
        for(int i=0;i<children.size();i++) {
            if(children.get(i) instanceof TransformableNode) {
                TransformableNode child=(TransformableNode)children.get(i);
                if(intersection==null) {
                    intersection=child.getIntersectionPoint(ray);
                    if(intersection!=null) {
                        distance=intersection.sub(ray.start).abs();
                    }
                } else {
                    Vector3D newIntersection=child.getIntersectionPoint(ray);
                    if(distance>newIntersection.sub(ray.start).abs()) {
                        intersection=newIntersection;
                        distance=intersection.sub(ray.start).abs();
                    }
                }
            }
        }
        
        return intersection;
    }

    public boolean isValidAppendixName(String appendix)
    {
        return false;
    }

    public Object getFromAppendix(String appendix)
    {
        return null;
    }

	@Override
	public String getType() {
		return "Root";
	}

}