Firing bullet from gun's current position to mouse x & y position

Java 2D
#1

Please help I’m kinda lost in my coding.

So I’ve created a bullet class:

package javagame.states;

import org.newdawn.slick.Color;
import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.Image;
import org.newdawn.slick.Input;
import org.newdawn.slick.SlickException;
import org.newdawn.slick.geom.Vector2f;
import org.newdawn.slick.state.StateBasedGame;

public class Bullet {

    private Vector2f pos;
    private Vector2f speed;
    private int lived = 0;

    private boolean aktiv = true;

    private static int MAX_LIFETIME = 2000;

    public Bullet (Vector2f pos, Vector2f speed){
        this.pos = pos;
        this.speed = speed;
    }

    public Bullet(){
        aktiv = false;
    }

    public void update(int t){

        rotation++;

        if(aktiv){
            Vector2f realSpeed = speed.copy();
            realSpeed.scale((t/1000.0f));
            pos.add(realSpeed);

            lived += t;
            if(lived > MAX_LIFETIME) aktiv = false;
        }
    }

    public void init(GameContainer gc, StateBasedGame sbg) throws SlickException{
    }

    public void render(GameContainer gc, Graphics g) throws SlickException {

        if(aktiv){
            g.setColor(Color.red);
            g.fillOval(pos.getX(), pos.getY(), 10, 10);
        }
    }

    public boolean isAktiv(){
        return aktiv;
    }
}

then called the bullet class here in my robot class:

package javagame.states;

import java.util.Iterator;
import java.util.LinkedList;

import org.newdawn.slick.GameContainer;
import org.newdawn.slick.Graphics;
import org.newdawn.slick.Input;
import org.newdawn.slick.SlickException;
import org.newdawn.slick.geom.Vector2f;
import org.newdawn.slick.state.BasicGameState;
import org.newdawn.slick.state.StateBasedGame;

public class Robot2 extends BasicGameState{

    private LinkedList<Bullet> bullets;

    @Override
    public void init(GameContainer gc, StateBasedGame sbg) throws SlickException {
        bullets = new LinkedList<Bullet>();
    }

    @Override
    public void render(GameContainer gc, StateBasedGame sbg, Graphics g) throws SlickException {
        for(Bullet b : bullets){
            b.render(gc, g);
        }       
    }

    @Override
    public void update(GameContainer gc, StateBasedGame sbg, int delta) throws SlickException {
        Iterator<Bullet> i = bullets.iterator();
        while(i.hasNext()){
            Bullet b = i.next();
            if(b.isAktiv()){
                b.update(delta);
            }else{
                i.remove();
            }
        }

        Input input = gc.getInput();
        int mouseX = input.getMouseX();
        int mouseY = input.getMouseY();

        int xDistance = (int) (RobotX() + Robotwidth() / 2 - mouseX); //RobotX is the robot image x position same to RobotY
        int yDistance = (int) (RobotY() + Robotheight() / 2 - mouseY);
        double angleToTurn = Math.toDegrees(Math.atan2(yDistance, xDistance));

            if(mouseX != 0){
            angleToTurn += 270;
            }else{
            if(mouseY != 0)
            angleToTurn += 180;
            }
            robot.setRotation((float) angleToTurn); //robot is an image. didn't included the code here to shorten my codes

                if(gc.getInput().isMousePressed(Input.MOUSE_LEFT_BUTTON)){
            bullets.add(new Bullet(new Vector2f(Sprites.getRobotX(), Sprites.getRobotY()), new Vector2f(mouseX, mouseY)));
        }
    }

    @Override
    public int getID() {
        return States.ROBOT;// has an integer value
    }

}

The robot is rotating perfectly according to mouse’s cursor movement but when I hit the mouse’s left button to fire a bullet, it doesn’t follow the mouse’s cursor location. This is what I’ve got when i run these codes and pressing the left button of my mouse. Please check my sample image.

http://s12.postimg.org/kwsr41p71/Untitled_1.jpg

What I want to achieve is to correct the direction of the bullet according to mouse cursor location.

Any help would be greately much appreciated. Thank you very much.