path: root/client/lib/life.js

/**
 * Game of Life
 * @module lib/life.js;
 */

let w, h, a, b, notes, assign;
function init(z, fn) {
  // really bad
  notes = z;
  assign = fn;
  build();
  setTempo(50);
}
function build() {
  w = notes.length;
  h = notes[0].length;
  a = a || new Array(w);
  b = b || new Array(w);
  for (var i = 0; i < w; i++) {
    a[i] = a[i] || new Array(h);
    b[i] = b[i] || new Array(h);
    for (var j = 0; j < h; j++) {
      a[i][j] = b[i][j] = notes[i][j] && notes[i][j].playing ? 1 : 0;
    }
  }
}
let timeout,
  delay = 1200; // ~120 bpm
function toggle() {
  build();
  if (timeout) {
    clearTimeout(timeout);
    timeout = null;
  } else {
    step();
  }
}
function assign_item(freq, state) {
  b[freq.i][freq.j] = state ? 1 : 0;
}
function setTempo(bpm) {
  console.log("bpm:", bpm);
  delay = 60000 / bpm;
}
function swap() {
  var tmp = a;
  a = b;
  b = tmp;
}
function step() {
  clearTimeout(timeout);
  timeout = setTimeout(step, delay);
  swap();
  let i, j, ni, pi, nj, pj, score, state;
  for (i = 0; i < w; i++) {
    for (j = 0; j < h; j++) {
      ni = i === 0 ? w - 1 : i - 1;
      pi = i === w - 1 ? 0 : i + 1;
      nj = j === 0 ? h - 1 : j - 1;
      pj = j === h - 1 ? 0 : j + 1;
      score =
        a[ni][nj] +
        a[ni][j] +
        a[ni][pj] +
        a[i][nj] +
        a[i][pj] +
        a[pi][nj] +
        a[pi][j] +
        a[pi][pj];
      state = fitness(a[i][j], score);
      b[i][j] = state;
      if (a[i][j] !== state) {
        assign(notes[i][j], state);
      }
    }
  }
}
function fitness(old, score) {
  if (old === 1) {
    if (score === 2 || score === 3) return 1;
  } else {
    if (score === 3) return 1;
  }
  return 0;
}
function isRunning() {
  return !!timeout;
}

export default { init, step, assign_item, toggle, setTempo, isRunning };

///// grid functions

const gliderShape = [
  [0, 0, 0, 0, 0],
  [0, 1, 1, 1, 0],
  [0, 0, 0, 1, 0],
  [0, 0, 1, 0, 0],
  [0, 0, 0, 0, 0],
];
const gliderShapeFlip = gliderShape.map((a) => a.slice(0).reverse());
const gliderShapes = [
  gliderShape,
  gliderShapeFlip,
  gliderShape.slice(0).reverse(),
  gliderShapeFlip.slice(0).reverse(),
];
function glider() {
  const x = Math.floor(Math.random() * ws);
  const y = Math.floor(Math.random() * hs);
  const shape = choice(gliderShapes);
  weave(x, y, shape);
}
function weave(x, y, shape) {
  const xmag = shape.length;
  const ymag = shape[0].length;
  let i, j, px, py;
  for (i = 0; i < xmag; i++) {
    for (j = 0; j < ymag; j++) {
      px = (x + i) % ws;
      py = (y + j) % hs;
      assign(notes[px][py], shape[i][j]);
    }
  }
}
function forEach(f) {
  let i, j, note, s;
  for (i = 0; i < ws; i++) {
    for (j = 0; j < hs; j++) {
      note = notes[i][j];
      s = f(i, j, note.playing);
      assign(note, s);
    }
  }
}
function clone() {
  let i, j;
  let a = [];
  for (i = 0; i < ws; i++) {
    a[i] = [];
    for (j = 0; j < hs; j++) {
      a[i][j] = notes[i][j].playing;
    }
  }
  return a;
}
function move(dx, dy) {
  let a = clone();
  forEach((x, y, state) => {
    x = (x + dx + ws) % ws;
    y = (y + dy + hs) % hs;
    return a[x][y];
  });
}
function clear() {
  forEach(() => {
    return false;
  });
}
function stripex(odd) {
  odd = !!odd;
  forEach((x) => {
    return x % 2 ? odd : !odd;
  });
}
function stripey(odd) {
  odd = !!odd;
  forEach((x, y) => {
    return y % 2 ? odd : !odd;
  });
}
function checker(odd, n) {
  odd = !!odd;
  n = n || 1;
  forEach((x, y) => {
    return Math.floor(x / n) % 2 ^ Math.floor(y / n) % 2 ? odd : !odd;
  });
}
function noise(n) {
  n = n || 0.5;
  n = n * n;
  forEach(() => {
    return Math.random() < n;
  });
}

/////////////////////////

let life_bpm = 50;
window.addEventListener("keydown", keydown, true);
function keydown(e) {
  // console.log(e.keyCode)
  if (e.altKey || e.ctrlKey || e.metaKey) return;
  switch (e.keyCode) {
    case 32: // space
      life.toggle();
      break;
    case 188: // comma
      life_bpm += e.shiftKey ? 1 : 5;
      life.setTempo(life_bpm);
      break;
    case 190: // period
      life_bpm -= e.shiftKey ? 1 : 5;
      life_bpm = Math.max(1, life_bpm);
      life.setTempo(life_bpm);
      break;
    case 37: // left
      move(1, 0);
      break;
    case 38: // up
      move(0, 1);
      break;
    case 39: // right
      move(-1, 0);
      break;
    case 40: // down
      move(0, -1);
      break;
    case 71: // g
      glider();
      break;
    case 83: // s
      swap_instrument();
      break;
    case 67: // c
      clear();
      break;
    case 87: // w
      clear();
      break;
    case 78: // n
      noise(0.5);
      break;
    case 69: // e
      stripex(Math.random() < 0.5);
      break;
    case 82: // r
      stripey(Math.random() < 0.5);
      break;
    case 84: // t
      checker(Math.random() < 0.5, 1);
      break;
    case 89: // y
      checker(Math.random() < 0.5, 2);
      break;
    case 85: // u
      checker(Math.random() < 0.5, 3);
      break;
    case 73: // i
      checker(Math.random() < 0.5, 4);
      break;
    case 79: // o
      checker(Math.random() < 0.5, 5);
      break;
    case 80: // p
      checker(Math.random() < 0.5, 6);
      break;
    case 219: // [
      checker(Math.random() < 0.5, 7);
      break;
    case 221: // ]
      checker(Math.random() < 0.5, 11);
      break;
    case 49: // 1
      noise(0.1);
      break;
    case 50: // 2
      noise(0.2);
      break;
    case 51: // 3
      noise(0.3);
      break;
    case 52: // 4
      noise(0.4);
      break;
    case 53: // 5
      noise(0.5);
      break;
    case 54: // 6
      noise(0.6);
      break;
    case 55: // 7
      noise(0.7);
      break;
    case 56: // 8
      noise(0.8);
      break;
    case 57: // 9
      noise(0.9);
      break;
    case 48: // 0
      noise(1);
      break;
  }
}