RigidBodyInfoManager.java

package de.fau.cs.mad.fly.game;

import java.util.HashMap;
import java.util.Map;

import com.badlogic.gdx.math.Vector3;
import com.badlogic.gdx.physics.bullet.collision.btCollisionShape;
import com.badlogic.gdx.physics.bullet.dynamics.btRigidBody;
import com.badlogic.gdx.physics.bullet.dynamics.btRigidBody.btRigidBodyConstructionInfo;
import com.badlogic.gdx.utils.Disposable;

/**
 * Manager for the btRigidBodyConstructionInfo.
 * <p>
 * Creates, stores and disposes all used rigid body construction infos.
 * 
 * @author Tobias Zangl
 */
public class RigidBodyInfoManager implements Disposable {
    
    /**
     * Map to save the different rigid body construction infos.
     */
    Map<String, btRigidBodyConstructionInfo> rigidBodyInfoMap;
    
    public RigidBodyInfoManager() {
        rigidBodyInfoMap = new HashMap<String, btRigidBodyConstructionInfo>();
    }
    
    /**
     * Getter for a rigid body construction info.
     * 
     * @param mass
     *            The id of the needed rigid body construction info.
     * @return btRigidBodyConstructionInfo
     */
    public btRigidBodyConstructionInfo getRigidBodyInfo(String infoId) {
        return rigidBodyInfoMap.get(infoId);
    }
    
    /**
     * Creates a new rigid body construction info if its not already created.
     * 
     * @param infoId
     *            The id of the needed rigid body construction info.
     * @param shape
     *            The used shape to calculate the local inertia.
     * @param mass
     *            The mass of the object.
     * @return btRigidBodyConstructionInfo
     */
    public btRigidBodyConstructionInfo createRigidBodyInfo(String infoId, btCollisionShape shape, float mass) {
        btRigidBodyConstructionInfo constructionInfo = rigidBodyInfoMap.get(infoId);
        if (constructionInfo != null) {
            return constructionInfo;
        }
        
        Vector3 localInertia = new Vector3();
        
        if (mass > 0f) {
            shape.calculateLocalInertia(mass, localInertia);
        } else {
            localInertia.set(0.0f, 0.0f, 0.0f);
        }
        constructionInfo = new btRigidBody.btRigidBodyConstructionInfo(mass, null, shape, localInertia);
        
        // Gdx.app.log("RigidBodyInfoManager", "Created rigid body info: " +
        // infoId + " with mass " + mass);
        
        rigidBodyInfoMap.put(infoId, constructionInfo);
        return constructionInfo;
    }
    
    @Override
    public void dispose() {
        for (btRigidBodyConstructionInfo info : rigidBodyInfoMap.values()) {
            info.dispose();
        }
        
        rigidBodyInfoMap.clear();
    }
}