let h = 10;

let s = 40;

​

let vel;

let player;

let spd = 0.1;

let spd_cap = 0.1;

​

let emitters = [];

​

let bullets = [];

​

let flask = [

  0,0,0,0,0,0,0,0,0,0,

  0,0,0,1,1,1,1,0,0,0,

  0,0,0,0,1,1,0,0,0,0,

  0,0,0,0,1,1,0,0,0,0,

  0,0,1,1,1,1,1,1,0,0,

  0,1,1,1,1,1,1,1,1,0,

  0,1,1,1,1,1,1,1,1,0,

  0,0,1,1,1,1,1,1,0,0,

  0,0,0,1,1,1,1,0,0,0,

  0,0,0,0,0,0,0,0,0,0,

];

​

let keys = {};

​

let hit = {};

​

let lastTime = 0;

​

function setup() {

  createCanvas(400, 400);

  player = createVector(4.5, 1.5);

  vel = createVector(0, 0);

  emitters.push(new Emitter(5, 5, 1, 0.5));

  emitters.push(new Emitter(5, 5, -1, 0.5));

}

​

function draw() {

  background(220);

  const currTime = millis();

  const d = (currTime - lastTime) / 1000;

  lastTime = currTime;

  handleInput(d);

  render();

  update(d);

}

​

function update(d) {

  hit[keyName(player.x | 0, player.y | 0)] = true;

  emitters.forEach(emitter => {

    emitter.update(d);

  });

  bullets = bullets.filter(bullet => bullet.update(d));

}

​

function render() {

  drawTiles();

  drawPlayer();

  emitters.forEach(emitter => {

    emitter.draw();

  });

  bullets.forEach(bullet => {

    bullet.draw();

  });

}

​

function keyName(i, j) {

  return i + ":" + j;

}

​

function idx(i, j) {

  return i + j * w;

}

​

function keyPressed() {

  keys[key] = true;

  // dash

  if(key == " ") {

    spd = spd_cap * 4;

  }

}

​

function keyReleased() {

  delete keys[key]

}

​

function handleInput() {

  let mv = createVector(0, 0);

  if(keys["w"]) mv.y -= 1;

  if(keys["s"]) mv.y += 1;

  if(keys["a"]) mv.x -= 1;

  if(keys["d"]) mv.x += 1;

  mv = mv.normalize();

  // dash

  if(spd - spd_cap > 0.001) {

    spd = (spd - spd_cap) * 0.8 + spd_cap;

  }

  let oldx = player.x;

  let oldy = player.y;

  vel.x = mv.x;

  vel.y = mv.y;

  player.x += vel.x * spd;

  player.y += vel.y * spd;

  if(!validTile(player.x, oldy)) {

    player.x = oldx;

  }

  if(!validTile(oldx, player.y)) {

    player.y = oldy;

  }

  if(!validTile(player.x, player.y)) {

    player.x = oldx;

    player.y = oldy;

  }

}

​

function validTile(i, j) {

  return flask[idx(i | 0, j | 0)] == 1;

}

​

function drawPlayer() {

  fill(200);

  ellipse(player.x * s, player.y * s, s/2, s/2);

}

​

function drawTiles() {

  for(let j = 0; j < h; j ++) {

    for(let i = 0; i < w; i ++) {

      if(keyName(i, j) in hit) {

        fill(200);

      } else if(flask[idx(i, j)] == 1) {

        fill(100);

      } else {

        fill(0);

      }

      rect(i * s, j * s, s, s);

    }

  }

}

​

class Emitter {

  constructor(x, y, rotSpeed, fireSpeed) {

    this.x = x;

    this.y = y;

    this.a = 0;

    this.rotSpeed = rotSpeed;

    this.fireSpeed = fireSpeed;

    this.timer = this.fireSpeed;

  }

  update(d) {

    this.timer += d;

    this.a += this.rotSpeed * d;

    if(this.timer > this.fireSpeed) {

      this.timer = 0;

      const b = new Bullet(this.x, this.y, p5.Vector.fromAngle(this.a));

      bullets.push(b);

    }

  }

  draw() {

    circle(this.x * s, this.y * s, s/2);

  }

}

​

class Bullet {

  constructor(x, y, vel) {

    this.pos = createVector(x, y);

    this.vel = vel;

  }

  update(d) {

    this.pos.add(p5.Vector.mult(this.vel, d));

    return validTile(this.pos.x, this.pos.y);

  }

  draw() {

    circle(this.pos.x * s, this.pos.y * s, s/4);

  }

}

​