How to make a bullet fire from the cannon angle

mozy

Hi! I have made a code for rotating the tank by pressing 'l' and 'r' and a bullet class using vectors and I have no idea how to make the bullet fire from the same angle as the cannon. Here is the code I wrote:

PImage cannon;
PImage bullet;
int x = 250;
int y = 100;
float rota=0;
void setup() {
  size(700, 700);
  background(0);
  cannon = loadImage("cannona.png");
  bullet = loadImage("fireball.png");
  image(cannon, width/2, height/2, 100, 200);
}

void draw() {

}

void keyPressed() {

  switch(key) {
  case 'l':
    background(0);
    pushMatrix();
    imageMode(CENTER);
    translate(x+cannon.width/2, y+cannon.height/2);
    rotate(rota);
    image(cannon, 0, 0, 100, 200);
    translate(x+cannon.width/2, y+cannon.height/2);
    popMatrix();
    rota=rota+0.1;
    break;
  case 'r':
    background(0);
    pushMatrix();
    imageMode(CENTER);
    translate(x+cannon.width/2, y+cannon.height/2);
    rotate(rota);
    image(cannon, 0, 0, 100, 200);
    translate(x+cannon.width/2, y+cannon.height/2);
    popMatrix();
    rota=rota-0.1;
    break;
  }
}

class Bullet {

  PVector pos;
  PVector vel;
  PVector acc;
  float friction = 0.99;
  float speed;

  float direction; 



  Bullet(PVector _pos, float _direction, float _speed) {
    pos = _pos.copy();
    vel = new PVector();
    acc = new PVector();
    direction = _direction;
    speed = _speed;
    this.initVel();
  }

  void update() {

    vel.add(acc);
    vel.mult(friction);
    pos.add(vel);
    acc.mult(0);
  }

  void display() {
    stroke(0, 255, 0);
    strokeWeight(2);
    pushMatrix();
    translate(pos.x, pos.y);
    line(vel.x*0.5, vel.y*0.5, 0, 0);
    popMatrix();
  }


  void initVel() {
    PVector dir = new PVector(cos(direction), sin(direction));
    dir.mult(speed);
    this.applyForce(dir);
  }

  void applyForce(PVector _force) {
    acc.add(_force);
  }

  boolean isDone() {
    return (pos.x < 0 || pos.x > width || pos.y < 0 || pos.y > height);
  }
}

koogs

is this homework? how do you have a Bullet class but not know how to use it?

add more code to your keyPressed() method so that 'f' key (for instance) creates a new bullet.

make this bullet a global variable, call it, say, myBullet.

you'll need to move all the drawing that you do in setup() into draw() and add a call that draws the bullet (myBullet.display())

you'll need to call myBullet.update() to move it, every frame, and call myBullet.isDone() to see if it's still moving.

GoToLoop

https://Forum.Processing.org/two/discussions/tagged?Tag=#bullet,#turret