Shooting in a game

Processing Coding Questions
1

Hello, I am a beginner to programming and I really want this shooting code in my game but I don’t know how to put this code so that my character in my game shoots these bullets please help:

//Objects
Player player = new Player();
//Bullet arraylist
ArrayList<Bullet> bullets;
//Vars to regulate shooting speed
boolean canShoot = true;
float canShootCounter;

int i;

void setup() {
  size(800, 600);
  //standard array setup
  bullets = new ArrayList<Bullet>();
  player = new Player();
}

void draw() {
  player.update();
  background(100);
  //since we are adding and removing objects so often, we need to do the forloop backwards preventing any nullPointer errors
  for (i = bullets.size()-1; i >= 0; i--) {
    //you need a seperate var to get the object from the bullets arraylist then use that variable to call the functions
    Bullet bullet = bullets.get(i);
    bullet.update();
  }
}

class Player {
  PVector location;
  Player() {
    location = new PVector(width/2, height/2);
  } 
  void update() {
    if (mousePressed == true) {
      // this regulates the shooting speed
      if (canShoot == true) {
        bullets.add( new Bullet());
        canShoot = false;
        canShootCounter = 0;
      }
    }
    // this checks if the right amount of time has passed before canShoot can = true again
    if (canShoot == false) {
      canShootCounter ++;
      //if the right amount of time has passed. make canShoot true
      if (canShootCounter == 5)/*change this number to change the duration*/{
        canShoot = true;
      }
    }
  }
}

class Bullet {
  //standard PVector used for the location of the bullet
  PVector location;
  //vars used to check the angle between location and the mouse
  float oldPosX, oldPosY, rotation, speed;
  Bullet() {
    //places the bullet in the middle of the room
    location= new PVector(width/2, height/2);
    //this checks the angle
    oldPosX = mouseX;
    oldPosY = mouseY;
    rotation = atan2(oldPosY - location.y, oldPosX - location.x) / PI * 180;
    //bullet speed
    speed = 10;//change this number to change the speed
  } 
  void update() {
    //move the bullet
    location.x = location.x + cos(rotation/180*PI)*speed;
    location.y = location.y + sin(rotation/180*PI)*speed;
    ellipse(location.x, location.y, 10, 10);

    //removes the bullet from the arrayList if it is off the room
    if (location.x > 0 && location.x < width && location.y > 0 && location.x < height) {
    }
    else {
      bullets.remove(i);
    }
  }
}

This is my game:

ArrayList <Spider> spiders = new ArrayList<Spider>();
PImage bg;
int numSpiders = 10;
boolean [] keys;
Player player;

void setup() {
  size(600, 600);
  frameRate(60);  
  bg = loadImage("grass.jpg");
  player = new Player();
  for (int i = 0; i < numSpiders; i++) {
    spiders.add(new Spider());
    keys = new boolean[128];
  }
}


void draw() { 
  image(bg, 0, 0);  
  move();
  player.drawPlayer();
  for (int i = 0; i < numSpiders; i++) {
    spiders.get(i).drawSpider();
  }
}

  void move() {
    int xDelta = 0;
    int yDelta = 0;

    if (keys['a'])
      xDelta = xDelta - 2;

    if (keys['d'])
      xDelta = xDelta + 2;

    if (keys['s'])
      yDelta = yDelta + 2;

    if (keys['w'])
      yDelta = yDelta - 2;

    player.updatePlayer(xDelta, yDelta);
  }
  void keyPressed() {
  keys[key] = true;
}

void keyReleased() {
  keys[key] = false;
}


class Player {
  float x, y;
  PImage spriteSheet;
  PImage [][] movement;
  boolean inMotion;
  int currentDirection;
  float currentFrame;
  final int UP = 0, LEFT = 1, DOWN = 2, RIGHT = 3;

  Player() {
    inMotion = false;
    currentDirection = 1;
    currentFrame = 0;
    x = width/2;
    y = height/2;

    setupSprites();
  }

  void setupSprites() {
    movement = new PImage[4][9];
    spriteSheet = loadImage("Spritesheet.png");
    for (int i = 0; i < 9; i++) {
      movement[0][i] = spriteSheet.get(16 + 64 * i, 8, 32, 56);
      movement[1][i] = spriteSheet.get(16 + 64 * i, 72, 32, 56);
      movement[2][i] = spriteSheet.get(16 + 64 * i, 136, 32, 56);
      movement[3][i] = spriteSheet.get(16 + 64 * i, 200, 32, 56);
    }
  }

  void drawPlayer() {
    if (inMotion)
      image(movement[currentDirection][1 + int (currentFrame)], x, y);
    else
      image(movement[currentDirection][0], x, y);
  }



  void updatePlayer(int xDelta, int yDelta) {
    currentFrame = (currentFrame + 0.5) % 8;
    inMotion =  true;

    if (xDelta == 0 && yDelta == 0)
      inMotion = false;
    else if (xDelta == -2)
      currentDirection = LEFT;
    else if (xDelta == 2)
      currentDirection = RIGHT;
    else if (yDelta == -2)
      currentDirection = UP;
    else if (yDelta == 2)
      currentDirection = DOWN;

    x = x + xDelta;
    y = y + yDelta;

    if(isPlayerOffScreen(x, y)) {
      x = x - xDelta;
      y = y - yDelta;
    }
  }

  boolean isPlayerOffScreen(float x, float y) {
    if (x < 0 || x > width - 30 ||
      y < 0 || y > height - 56)
      return true;
    return false;
  }
}


class Spider {
  float x, y;
  PVector speed;
  PImage img;
  


  Spider() {
    x = random(50, 450);
    y = random(50, 450);
    speed = new PVector();
    speed.x = random(-1, 1);
    speed.y = random(-1, 1);
    img = loadImage("spider.png");
    
  }


  void drawSpider() {
    moveSpider();
    pushMatrix();
    translate(x + img.width/2, y + img.height/2);
    img.resize(0, 40);
    rotate(speed.heading() + PI/2);
    translate(-img.width/2, -img.height/2); 
    image(img, 0, 0);
    popMatrix();
  }

  void moveSpider() {
    float testMove = random(0, 1);
    if (testMove < 0.10) {
      speed.rotate(random(-0.4, 0.4));
    }

    if (testMove > 0.97) {
      speed.rotate(random(-1, 1));
    }
    x = x + speed.x;
    y = y + speed.y;


    if (isSpiderOffScreen() == true) {
      x = x - speed.x;
      y = y - speed.y;
      speed.rotate(random(-2, 2));
    }
  }

  boolean isSpiderOffScreen() {
    if (x < 30 || x > width - 30 || 
      y < 30 || y > height - 30)
      return true;
    return false;
  }
}```
2

can someone please help me with this issue?

3

It’s really hard to answer general “how do I do this” type questions. You’ll have much better luck if you break your problem down into smaller steps and take those steps on one at a time. For example, can you create a sketch that shows a single hard-coded rectangle that “shoots” circles when you click?

If you get stuck on that, then you can post a MCVE along with a more specific question. Good luck!

You might also read this for some tips on asking questions:

5

hmm maybe maybe not…:pensive:

6

Give your Player an ArrayList<Bullet> bullets;. Then you can make a function void shoot() {}, and void update() {}. Eg.

void shoot() {
  bullets.add(new Bullet(position,atan2(mouseY-y,mouseX-x))); // Add a position and rotation parameter to your Bullet class
}
void update() {
  for(Bullet b : bullets) {
    b.update();
  }
}