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Null pointer exception

[7 Replies]
- 20-Mar-2013 02:42 PM
- Forum: Core Library Questions
I get a null pointer exception error message and all i am trying to do is apply text to the programe with an int for the player score... However when i call upon the function of the ScoreUp class in draw, i get the error. Seems silly for such a simple thing!!!

Any hep appreciatted, ill just pop the code up....

//Main class

Star [] star = new Star [50];//Declare as a collection/array of stars and the size - 50.
Enemy [] enemy = new Enemy[3];//Declare classes
Planet [] planet = new Planet[6];

ArrayList bulletCollection;

Score score;
User user;

import ddf.minim.*;

Minim minim;
AudioPlayer player;
AudioSample crash;

void setup() {
size(1000, 700, P3D);
smooth();

minim = new Minim(this);
player = minim.loadFile("theme.mp3");
//player.play();
crash = minim.loadSample("crash.mp3");

bulletCollection = new ArrayList();

for (int i = 0; i < 6; i ++) {
    planet [i] = new Planet(random(0, width), random(0, height), 15, 15);
}

for (int i = 0; i < enemy.length; i ++) {
    enemy [i] = new Enemy(1050, random(100, 600), 50, 50);//initialize parameters in here
}

PImage simg = loadImage("ship.jpg");
user = new User(75, 350, simg);

for (int i = 0; i < 50; i ++) {
    star [i] = new Star(random (0, width), random(0, height), 5, 5);
}
}

void draw() {

background(0);
noStroke();

score.displayScore();

for (int i = 0; i < bulletCollection.size() ; i ++) {
     Bullets bullets = (Bullets) bulletCollection.get(i);
     bullets.run();

}

for (int i = 0; i < 50; i ++) {
    star[i].run();//call upon all elements of the array. If i was a 0 itwould call one star
    star[i].move();
    if (star[i].x < 0) {
      star [i] = new Star( width, random(0, height), 5, 5);
    }
}

for (int i = 0; i < enemy.length; i ++) {
    enemy[i].run();
}

for (int i = 0; i < 6; i ++) {
    planet[i].display();
    planet[i].move();
    if (planet[i].x < 0) {
      planet [i] = new Planet(random(1000, 1200), random(0, height), 15, 15);
    }
}

user.run();

}

void keyPressed() {
//println(user.playerSpeedX);
user.move();
}

void mousePressed() {

Bullets bullets = new Bullets(user.imgX + 172, user.imgY + 42, 5, 2);
bulletCollection.add(bullets);
}

void stop()
{
// always close Minim audio classes when you are done with them
player.close();
crash.close();
minim.stop();

super.stop();
}

//Bullet Class

class Bullets {

float x, y, w, h;
float bulletSpeed = 8;
boolean hit = false;
boolean active = true;
int playerScore = 0;

Bullets(float posX, float posY, float Width, float Height) {

    x = posX;
    y = posY;
    w = Width;
    h = Height;
}

void run() {
    display();
    moveBullet();
    collision();

}

void display() {
    fill (255, 255, 44);
    rect(x, y, w, h);
}

void moveBullet() {
    x += bulletSpeed;
    if (x >= width) {
      active = false;
    }
}

void collision() {
    for (int i = 0; i < bulletCollection.size();i++) {
      Bullets bullets = (Bullets) bulletCollection.get(i);
      for (int j = 0; j < enemy.length ; j ++) {
        if (x+w >= enemy[j].x && x <= enemy[j].x + enemy[j].w
          && y+h >= enemy[j].y && y <= enemy[j].y + enemy[j].h && active != false) {
          enemy[j].x = width;
          hit = true;
          bulletCollection. remove(i);
          println(playerScore);
        }
        else {
          hit = false;
        }
      }
    }
}
}

//Enemy Class

class Enemy {

float x, y, w, h;
float Xspeed = -7;
float Yspeed = -5;
float YspeedC = 2;
boolean collide = false;
float collideFall = 8;
float fillCol = 0;

Enemy (float posX, float posY, float Width, float Height) {
    x = posX;
    y = posY;
    w = Width;
    h = Height;
}

void run() {
    show();
    move();
    changeover();
    collide();
    boom();
    reset();
}

void show() {
    fill(255, 255, fillCol);
    rect(x, y, w, h);
}

void move() {
    x += Xspeed;
    y += Yspeed;
}

void changeover() {
    if (y <= 100|| y >= 600) {
      Yspeed = Yspeed *-1;
    }
}

void collide() {
    if (x >= user.imgX && x <= user.imgX + 172
      && y >= user.imgY && y <= user.imgY + 90) {
      Xspeed = 0;
      Yspeed = 0;
      collide = true;
    }
}

void boom() {
    if ((collide)) {
      user.imgY += collideFall;
      //crash.trigger();
    }
    else {
      collide = false;
    }
}

void reset() {
    if (x <= 0) {
      x = width;
      y = random(0,700);
    }
}
}

//planet class

class Planet{

float x,y,w,h;
float planetSpeed = 5;

Planet(float PosX, float PosY, float Width, float Height){
    x = PosX;
    y = PosY;
    w = Width;
    h = Height;

}

void display(){
    fill(random(0,255),random(0,255), random(0,255));
    ellipse(x,y,w,h);
    noStroke();
}

void move(){
    x -= planetSpeed;
}
}

//Score class

class Score {

int playerScore = 0;

void displayScore() {
    fill(255);
    textSize(30);
    text (playerScore, 50, 50);
}
}

//Star Class

class Star {
float x, y, w, h;
float starSpeed = 7;
Star( float posx, float posy, float posw, float posh ) {
    x = posx;
    y = posy;
    w = posw;
    h = posh;
}

void run(){
    display();
}

void display(){
    fill(255);
    ellipse(x,y,w,h);
    strokeWeight(2);
}

void move(){
    x -= starSpeed;

}
}

//User Class

class User {

float x, y, w, h;
float playerSpeedY = 15;
float playerSpeedX = 15;
PImage img;
float imgX = 75;
float imgY = 350;

User (float posX, float posY, PImage img) {
    this.x = posX;
    this.y = posY;
    this.img = img;
}

void run() {
    display();
    bulletTracker();
}

void display() {

    image(img, imgX, imgY);
}

void bulletTracker() {
    fill(255, 255, 0);
    ellipse(imgX + 172, imgY + 45, 10, 10);
}

void move() {
    if (keyCode == UP) {
      imgY -= playerSpeedY;
    }
    else if (keyCode == DOWN) {
      imgY += playerSpeedY;
    }
    else if (keyCode == LEFT) {
      imgX -= playerSpeedX;
    }
    else if (keyCode == RIGHT) {
      imgX += playerSpeedX;
    }
}
}

Many thanks!

Why does my bullet arrayList stop working when the spaceship is moved with void keyPressed????

[11 Replies]
- 12-Mar-2013 01:43 PM
- Forum: Programming Questions
I am new to Processing and was wondering if anyone would be so kind as to help me with this puzzler. The bullets start to fire with the mousePressed option..... however when they do the spaceship will not respond to movements with the left right keys... Any ideas would be appreciatted...

Many thanks..

Star [] star = new Star [50];//Declare as a collection/array of stars and the size - 50.
Enemy [] enemy = new Enemy[3];//Declare classes
Planet [] planet = new Planet[6];

ArrayList bulletCollection;

User user;

import ddf.minim.*;

Minim minim;
AudioPlayer player;
AudioSample crash;

void setup() {
size(1000, 700, P3D);
smooth();

minim = new Minim(this);
player = minim.loadFile("theme.mp3");
player.play();
crash = minim.loadSample("crash.mp3");

bulletCollection = new ArrayList();
//for (int i = 0; i < 20; i ++) {
    //Bullets bullets = new Bullets(200, 200, 40, 40);
    //bulletCollection.add(bullets);
//}

for (int i = 0; i < 6; i ++) {
    planet [i] = new Planet(random(0, width), random(0, height), 15, 15);
}

for (int i = 0; i < 2; i ++) {
    enemy [i] = new Enemy(1050, random(100, 600), 50, 50);//initialize parameters in here
}

PImage simg = loadImage("ship.jpg");
user = new User(75, 350, simg);

for (int i = 0; i < 50; i ++) {
    star [i] = new Star(random (0, width), random(0, height), 5, 5);
}
}

void draw() {

background(0);
noStroke();

for (int i = 0; i < bulletCollection.size() ; i ++) {
    Bullets bullets = (Bullets) bulletCollection.get(i);
    bullets.run();
}

for (int i = 0; i < 50; i ++) {
    star[i].run();//call upon all elements of the array. If i was a 0 itwould call one star
    star[i].move();
    if (star[i].x < 0) {
      star [i] = new Star( width, random(0, height), 5, 5);
    }
}

for (int i = 0; i < 2; i ++) {
    enemy[i].run();
}

for (int i = 0; i < 6; i ++) {
    planet[i].display();
    planet[i].move();
    if (planet[i].x < 0) {
      planet [i] = new Planet(random(1000, 1200), random(0, height), 15, 15);
    }
}

user.run();
}

void keyPressed() {
user.move();
}

void mousePressed() {

Bullets bullets = new Bullets(user.imgX + 172, user.imgY + 42, 5, 2);
bulletCollection.add(bullets);
}

void stop()
{
// always close Minim audio classes when you are done with them
crash.close();
minim.stop();

super.stop();
}

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