Processing: Multiple bullets in top down shooter - processing

Question

I am trying to make a simple top down shooter. When the user presses W, A, S or D a 'bullet' (rectangle) will come out of the 'shooter'. With my code, you can only shoot one bullet per direction until it reaches the end of the screen. Is there a way to make it so they (the user) can shoot multiple bullets in one direction?
Here's my code:
package topdownshooter;
import processing.core.PApplet;
import processing.core.PImage;
public class TopDownShooter extends PApplet {
PImage shooter;
float shooterX = 400;
float shooterY = 300;
float u_bulletSpeed;
float l_bulletSpeed;
float d_bulletSpeed;
float r_bulletSpeed;
boolean shootUp = false;
boolean shootLeft = false;
boolean shootDown = false;
boolean shootRight = false;
public static void main(String[] args) {
PApplet.main("topdownshooter.TopDownShooter");
}
public void setup() {
shooter = loadImage("shooter.png");
}
public void settings() {
size(800, 600);
}
public void keyPressed() {
if(key == 'w') {
shootUp = true;
}
if(key == 'a') {
shootLeft = true;
}
if(key == 's') {
shootDown = true;
}
if(key == 'd') {
shootRight = true;
}
}
public void draw() {
background(206);
imageMode(CENTER);
image(shooter, shooterX, shooterY);
if(shootUp == true) {
rect(shooterX, shooterY-u_bulletSpeed, 5, 5);
u_bulletSpeed += 2;
if(u_bulletSpeed > 300) {
u_bulletSpeed = 0;
shootUp = false;
}
}
if(shootLeft == true) {
rect(shooterX-l_bulletSpeed, shooterY, 5, 5);
l_bulletSpeed += 2;
if(l_bulletSpeed > 400) {
l_bulletSpeed = 0;
shootLeft = false;
}
}
if(shootDown == true) {
rect(shooterX, shooterY+d_bulletSpeed, 5, 5);
d_bulletSpeed += 2;
if(d_bulletSpeed > 300) {
d_bulletSpeed = 0;
shootDown = false;
}
}
if(shootRight == true) {
rect(shooterX+r_bulletSpeed, shooterY, 5, 5);
r_bulletSpeed += 2;
if(r_bulletSpeed > 400) {
r_bulletSpeed = 0;
shootRight = false;
}
}
}
}
The language is processing and I am using the eclipse IDE.
Thanks!

Answer 1

Here's what I would do if I were you. First I'd encapsulate your bullet data into a class, like this:
class Bullet{
float x;
float y;
float xSpeed;
float ySpeed;
// you probably want a constructor here
void drawBullet(){
// bullet drawing code
}
}
Then I'd create an ArrayList that holds Bullet instances:
ArrayList<Bullet> bullets = new ArrayList<Bullet>();
To add a bullet, I'd create a new instance and add it to the ArrayList like this:
bullets.add(new Bullet(bulletX, bulletY));
Then to draw the bullets, I'd iterate over the ArrayList and call the corresponding function:
for(Bullet b : bullets){
b.drawBullet();
}
Shameless self-promotion:
Here is a tutorial on creating classes.
Here is a tutorial on using ArrayLists.