«Оживление» сцены. Движение объектов по сцене

package kz.dsdk.aquarium.models;

import com.badlogic.gdx.math.Vector3;

/**
 * Created by ytzh on 1/18/16.
 */
public class Object {
    Vector3 position;
    Vector3 velosity;

    public Object(Vector3 position, Vector3 velosity){
        this.position = position;
        this.velosity = velosity;
    }

    public Vector3 getPosition() {
        return position;
    }

    public Vector3 getVelosity() {
        return velosity;
    }
}

package kz.dsdk.aquarium.models;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.math.MathUtils;
import com.badlogic.gdx.math.Vector3;
import com.badlogic.gdx.utils.Array;

import kz.dsdk.aquarium.controllers.WorldController;

/**
 * Created by ytzh on 1/18/16.
 */
public class World {
    private Array<Object> objects;


    Texture bgt;
    Texture objt;
    WorldController worldController;
    private int width, height;

    public Array<Object> getObjects() {
        return objects;
    }

    public Texture getBgt() {
        return bgt;
    }

    public Texture getObjt() {
        return objt;
    }

    public World(int width, int height) {
        this.width = width;
        this.height = height;
        this.worldController = new WorldController(this);

        objects = new Array<Object>();
        this.bgt  = new Texture(Gdx.files.internal("sea.jpg"));
        this.objt = new Texture(Gdx.files.internal("ball.png"));
        for(int i = 0; i<60;i++){
            objects.add(new Object(new Vector3( //Координаты
                                                MathUtils.random(0,this.width-objt.getWidth()),
                                                MathUtils.random(0,this.height-objt.getHeight()),0),
                                    new Vector3(//Скорость
                                                MathUtils.random(20,150),
                                                MathUtils.random(20,150),0)));
        }
    }

    public void render(SpriteBatch sb){
        sb.draw(bgt,0,0);
        for(Object obj:objects){
            sb.draw(objt,obj.getPosition().x,obj.getPosition().y);
        }
        worldController.update();
    }

    public void dispose(){
        bgt.dispose();
        objt.dispose();
    }
}

package kz.dsdk.aquarium.controllers;

import com.badlogic.gdx.Gdx;

import kz.dsdk.aquarium.models.*;

/**
 * Created by ytzh on 1/18/16.
 */
public class WorldController {
    private World world;

    public WorldController(World world) {
        this.world = world;
    }

    public void update(){
        for(kz.dsdk.aquarium.models.Object object:world.getObjects()){
            if(object.getPosition().x>=world.getBgt().getWidth()-world.getObjt().getWidth() || object.getPosition().x<= 0 ){
                object.getVelosity().x *= -1;
            }
            if(object.getPosition().y>=world.getBgt().getHeight()-world.getObjt().getHeight() || object.getPosition().y<= 0 ){
                object.getVelosity().y *= -1;
            }
            object.getPosition().add(object.getVelosity().x * Gdx.graphics.getDeltaTime(),object.getVelosity().y*Gdx.graphics.getDeltaTime(),0);
        }
    }
}