Hi.
I am making a really simple program to refresh my knowledge in java (which is obviously needed). When I click the screen, I want a bullet to appear in the center and move towards the point I clicked. Right now, when I click on the left half the bullet will go either straight up or directly left, and if I click the right half then it just stays in the center of the screen.
I have two classes (plus a third main class):
ShooterPanel class

package shooter;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.*;

public class ShooterPanel extends JPanel implements Runnable, MouseListener {

    boolean gameOver;
    int aimFPS = 60;

    int mouseX;
    int mouseY;
    boolean hasShot;
    Thread t = new Thread(this);

    Bullet[] bullets = new Bullet[100];

    public ShooterPanel(){

        addMouseListener(this);
        t.start();

    }

    public void fireShots(){

        if(hasShot){

            for(int i = 0; i < bullets.length; i++){

                if(bullets[i] == null){

                    bullets[i] = new Bullet(200, 200, mouseX, mouseY);
                    double angle = Math.atan2(bullets[i].targetY - bullets[i].posY, bullets[i].targetX - bullets[i].posX);
                    if(angle < 0){
                        angle += 360;
                    }
                    bullets[i].setAim(angle);
                    System.out.println("Created a new bullet object");
                    break;

                }

            }
            hasShot = false;

        }

    }

    public void moveBullets(){

        for(Bullet bullet : bullets){

            if(bullet != null){

                bullet.move();
                System.out.println("New bullet position is [" + bullet.posX + ", " + bullet.posY + "]");

            }

        }

    }

    @Override
    public void paintComponent(Graphics gc){

        super.paintComponent(gc);

        for(Bullet bullet : bullets){

            if(bullet != null){
                gc.setColor(Color.BLACK);
                gc.fillOval(bullet.posX, bullet.posY, 7, 7);
                System.out.println("Drew a bullet");
            }

        }
        gc.setColor(Color.BLACK);
        gc.fillOval(50, 50, 20, 20);
        gc.drawString("Hiya", 80, 80);

    }

    @Override
    public void run(){

        while(!gameOver){

            fireShots();

            moveBullets();

            repaint();

            try{
                Thread.sleep(1000 / aimFPS);
            }catch(InterruptedException ie){
                t.interrupt();
                System.out.println("Couldn't pause thread");
            }

        }

    }

    @Override
    public void mouseClicked(MouseEvent e) {

    }

    @Override
    public void mousePressed(MouseEvent e) {

    }

    @Override
    public void mouseReleased(MouseEvent e) {
        mouseX = e.getX();
        mouseY = e.getY();
        hasShot = true;
        System.out.println("Heard mouse realease at [" + mouseX + ", " + mouseY + "]");
    }

    @Override
    public void mouseEntered(MouseEvent e) {

    }

    @Override
    public void mouseExited(MouseEvent e) {

    }

}

Bullet class

package shooter;

public class Bullet {

    int posX;
    int posY;
    int targetX;
    int targetY;
    double aim;

    public Bullet(int posX, int posY, int targetX, int targetY){

        this.posX = posX;
        this.posY = posY;
        this.targetX = targetX;
        this.targetY = targetY;

    }

    public double getAim(){

        return aim;

    }

    public void setAim(double angle){

        this.aim = angle % (2 * Math.PI);

    }

    public void move(){

        double stepX = Math.cos(getAim());
        double stepY = Math.sin(getAim());
        posX += stepX;
        posY += stepY;

    }

}

28eab7aac59212799405257a808b9fcb
this is a picture of what happens. The bullets are either going straight up or directly left, not even diagonal.

Edited 2 Years Ago by Benny_1

The code does angle calcs using 360 in one place and 2pi in another, so maybe you are mixing or confusing degrees and radians?

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