子弹射击不正确

Question

I've been trying to make a bullet shoot when I click. It partly works, but the thing is that it's moving with the ship instead up directly up (like I want it to go).

I think this may be due to the fact that the x and y coordinates are pointing to the ship is there any way around this? Here is my code:

 package galaga.display.players;

import galaga.display.Game;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;

public class Bullet {
    private  int x;
    private  int y;
    private final int size = 16;
    public boolean hasClicked;
    Rectangle bullet;
    public Bullet() {


        setX(Game.getPlayer1().getX()+Game.getPlayer1().getSize()/3);
        setY(Game.getPlayer1().getY()-Game.getPlayer1().getSize());

    }
    private void setX(int x){
        this.x = x;
    }
    private void setY(int y){
        this.y = y;
    }
    public int getY(){
        return y;
    }
    public int getX(){
        return x;
    }
    public void render(Graphics g){
        if(hasClicked){
            g.setColor(Color.red);
            g.fillOval(x,y, size, size);
        }

    }

    public void update(Game game){

        if(hasClicked){


            y--;

        }

    }
}

Here is my Ship/PLayer Class :

package galaga.display.players;

import galaga.display.Game;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;

public class Players {
    public boolean isUp,isDown,isLeft,isRight;
    private int x, y;
    private int size = 50;
    private BufferedImage image2;
    private Rectangle boundingBox;
    boolean hasCollided = false;
    public Players(int x,int y) {
        setY(y);
        setX(x);
        try {
            image2 = ImageIO.read(new File("C:\\Users\\Anonymous\\Desktop\\SpaceShip.png"));
        } catch (IOException e) {

            e.printStackTrace();
        }
        setBoundingBox(new Rectangle(x,y,size,size));

    }
    private void setY(int y){
        this.y = y;
    }
    private void setX(int x){
        this.x = x;
    }
    public int getX(){
        return x;
    }
    public int getY(){
        return y;
    }
    public int getSize(){
        return size;
    }
    public void render(Graphics g){


        g.setColor(Color.black);
        g.drawImage(image2,x,y,size,size,null);

    }
    public void update(Game game){
        Rectangle rect = game.getRectangle();
        getBoundingBox().setBounds(x, y, size, size);

        if(isUp){
            y--;
        }
        else if (isDown){
            y++;
        }
        else if(isLeft){
            x--;
        }
        else if(isRight){
            x++;
        }

        if (x < 0 || x + size >= rect.width) {
            // change the direction
            x *= -1;
        }
        if (y < 0 || y + size >=rect.height) {
            // change the direction
            y*= -1;
        }



    }
    public Rectangle getBoundingBox() {
        return boundingBox;
    }
    public void setBoundingBox(Rectangle boundingBox) {
        this.boundingBox = boundingBox;
    }

}

Answer 1

Static Variables: As many have stated there are a few issues with the code beyond the bullet not being where you want it to be. First of all your static variables should not be static.

Static variables are not unique to each instance of the object and remain constant across all objects of that class. (IE Every bullet will have the same x y coordinates).

Update Method: Also I have no idea when or how you are calling the update() method, but if you are only calling the update method when a user clicks then your bullet is only going to move when a user clicks... IE they have to pump the bullet up the screen via clicking.

You probably want to call the update method in your main game's update method so that the bullet is updated and redrawn with the game itself.

Lastly your update method should not be creating new bullets, it just needs to update the x and y coordinates of that bullet and redraw it, or in your case, just the y variable.

package galaga.display.players;

import galaga.display.Game;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;

public class Bullet {
    private int x;
    private int y;
    private final int size = 16;
    Rectangle bullet;
    public Bullet() {

        setX(Game.getPlayer1().getX()+Game.getPlayer1().getSize()/3);
        setY(Game.getPlayer1().getY()-Game.getPlayer1().getSize());
    }
    private void setX(int x){
        this.x = x;
    }
    private void setY(int y){
        this.y = y;
    }
    public int getY(){
        return y;
    }
    public int getX(){
        return x;
    }
    public static void render(Graphics g){  // Call this in your main game's paint method

            g.setColor(Color.red);
            g.fillOval(x,y, size, size);
        }
    }

    public static void update(Game game){
     //removed the creating a new bullet from the update.
            y--;
    }
}

Lastly I removed the hasClicked variable. It doesn't make much sense to have a bullet with a hasClicked variable, since the bullet should never care if a user is clicking, that's something the main game should worry about.

Additionally you set hasClicked to true in the constructor, and never modified the value or changed it to false so it will always be true and therefore it's pointless anyhow.