​

let fireTimerMS = 0;

const fireTimerMSMax = 100;

​

const bulletSpeed = 500;

​

let currTime = 0, prevTime = 0;

​

let prevMouseX = 0, prevMouseY = 0;

​

let player;

​

function setup() {

  createCanvas(400, 400);

  player = new Player(width/2, height/2);

}

​

function draw() {

  background(50);

  prevTime = currTime;

  currTime = millis();

  const delta = currTime - prevTime;

  player.update(delta);

  player.draw();

  shoot(delta);  

  bullets = bullets.filter(bullet => {

    const dead = bullet.update(delta);

    bullet.draw(delta);

    return !dead;

  });

}

​

function shoot(delta) {

  if(fireTimerMS > 0) {

    fireTimerMS -= delta;

  }

  if(canFire()) {

    fire();

  }

}

​

function canFire() {

  return mouseIsPressed && fireTimerMS <= 0;

}

​

function fire() {

  const vel = player.vel.copy();

  vel.setMag(bulletSpeed);

  bullets.push(new Bullet(player.x, player.y, vel.x, vel.y));

  fireTimerMS = fireTimerMSMax;

}

​

class Bullet {

  constructor(x, y, vx, vy) {

    this.x = x;

    this.y = y;

    this.vx = vx;

    this.vy = vy;

  }

  update(delta) {

    this.x += this.vx * (delta/1000);

    this.y += this.vy * (delta/1000);

    return this.x < 0 || this.x > width || this.y < 0 || this.y > height;

  }

  draw(delta) {

    stroke(0, 255, 255);

    strokeWeight(2);

    line(this.x, this.y, this.x + (this.vx * delta/1000), this.y + (this.vy * delta/1000));

  }

}

​

class Player {

  constructor(x, y) {

    this.x = x;

    this.y = y;

    this.vel = createVector(0, 0);

    this.maxVel = 2;

    this.maxForce = 1;

  }

  update(delta) {

    const desired = createVector(mouseX - this.x, mouseY - this.y);

    desired.setMag(this.maxVel);

    const steering = desired.copy().sub(this.vel);

    if(steering.mag() > this.maxForce) {

      steering.setMag(this.maxForce);

    }

    this.vel = this.vel.add(steering);

    this.x += this.vel.x;

    this.y += this.vel.y;

  }

  draw() {

    stroke(255);

    circle(this.x, this.y, 10);

  }

}

​

​

​

​