checkcollisionvisitor.java

M3DEA (Mobile 3D Engine API) 手机3D引擎API

/*
 *M3DEA - MOBILE 3D ENGINE API
 *Copyright (C) 2006 Alexandre Watanabe         [e-mail]     
 *		     Diego de Freitas           [e-mail]
 *		     Paulo Rodrigo Priszculnik  [e-mail]
 *		     Rodrigo Arthur Lopes       [e-mail]
 *
 * 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., 59 Temple Place, Suite
 * 330, Boston, MA 02111-1307 USA
 *
 */

package m3dea.physics;

import java.util.Enumeration;
import m3dea.entities.*;
import m3dea.util.BBox;
import m3dea.util.Vector3D;

import javax.microedition.m3g.*;

/**
 * Visitor que faz checagem de colis鉶 entre as entidades da cena
 */
public class CheckCollisionVisitor  extends EntityVisitor
{
    
    /**
     * Cria uma nova inst鈔cia de CheckCollisionVisitor
     */
    public CheckCollisionVisitor()
    {
    }

    /**
     * Recebe um Sprite para fazer a checagem de Colis鉶
     * @param node Sprite para verificar colis鉶
     */
    public void visitMobileEntity(Sprite node)
    {
        if( !node.isCollidable() ) return; 
        Entity entity = null;
        
        Enumeration en = EntityManager.getInstance().getEntities();
        while(en.hasMoreElements())
        {            
            entity = (Entity) en.nextElement();
            
            float[] vec = node.getMoveVector();            
            if(vec[0] == 0 && vec[1] == 0 && vec[2] == 0) continue;
            
            // calcula colisao 1 frame a frente
            BBox box = node.getBoundingBox();            

            box.translate(vec);

            float[] normal = box.checkCollision(entity.getBoundingBox(), vec);
            if( normal != null )
            {
                if(entity instanceof Portal)
                {
                    ((Portal) entity).onEnter(node);
                    //node.setMoveVector( new float[]{0,0,0} );
                }
                // ocorreu colisao
                else if( entity.isCollidable() )
                {
                    float[] resp = Vector3D.mirror(vec, normal);                    
                    float[] bounce = node.getBouncefactor();
                    BBox b = new BBox( box );
                    b.translate( Vector3D.scalarMul(-1, vec) );
                    resp = new float[]{resp[0]*bounce[0],resp[1]*bounce[1],resp[2]*bounce[2]};
                    b.translate( resp );
                    if( b.checkCollision(entity.getBoundingBox(), resp) == null )
                        node.setMoveVector( resp );
                }

                node.onCollision(entity);
            }

            // restaura valores originais do box
            box.translate( Vector3D.scalarMul(-1, vec) );
           
        }
    }    

    /**
     * M閠odo n鉶 utilizado pois entidades est醫icas n鉶 colidem
     * @param node Entity
     */
    public void visitEntity(Entity node){ /* objetos est醫icos n鉶 fazem detec玢o de colis鉶 */ }

    

}