namastejs/src/games/snake/game.js

A spiritual greeting from your JavaScript code. Because every function deserves a 'Namaste 🙏'

const { render } = require("./render");

function randomFood(WIDTH, HEIGHT, snake) {
  let pos;
  do {
    pos = {
      x: Math.floor(Math.random() * WIDTH),
      y: Math.floor(Math.random() * HEIGHT),
    };
  } while (snake.some((p) => p.x === pos.x && p.y === pos.y));
  return pos;
}

function update(state, config) {
  if (state.paused || state.status !== "RUNNING") return;

  const head = { ...state.snake[0] };

  if (state.dir === "UP") head.y--;
  if (state.dir === "DOWN") head.y++;
  if (state.dir === "LEFT") head.x--;
  if (state.dir === "RIGHT") head.x++;

  const hitWall =
    head.x < 0 ||
    head.y < 0 ||
    head.x >= config.WIDTH ||
    head.y >= config.HEIGHT;

  const hitSelf = state.snake.some((p) => p.x === head.x && p.y === head.y);

  if (hitWall || hitSelf) {
    state.status = "GAME_OVER";
    state.collision = { ...head };
    return;
  }

  state.snake.unshift(head);

  if (head.x === state.food.x && head.y === state.food.y) {
    state.score++;
    state.speed = Math.max(config.MIN_SPEED, state.speed - 4);
    state.food = randomFood(config.WIDTH, config.HEIGHT, state.snake);
  } else {
    state.snake.pop();
  }
}

function startGame(state, config) {
  state.food = randomFood(config.WIDTH, config.HEIGHT, state.snake);

  function loop() {
    update(state, config);
    render(state, config);
    setTimeout(loop, state.speed);
  }

  loop();
}

module.exports = { startGame };