worker_labyrinth.js

/* eslint-disable */
// worker_labyrinth.js

let a;
let rows;
let cols;
let finished;
let found;
let slow;
// finished: 1|-1 found: 1|-1 data: a

self.onmessage = (event) => {
  //	receiving: { a: a, rows: rows , cols: cols, slow: slow});
  a = event.data.a;
  rows = event.data.rows;
  cols = event.data.cols;
  slow = parseInt(event.data.slow);

  found = wayout(0, 0);

  if (found == 1) {
    postMessage({
      finished: 1,
      found: 1,
      element: 'green',
      yy: 0,
      xx: 0,
    });
  } else {
    postMessage({
      finished: 1,
      found: -1,
      element: 'green',
      yy: 0,
      xx: 0,
    });
  }
};

let wayout = (x, y) => {
  console.log(`slow= ${slow}${1}`);

  // REKURSIONSABBRUCH; REKURSIONSABBRUCH
  // Abbruch, wenn ausserhalb des Labs

  if (x < 0 || x >= cols) {
    return -1;
  }
  if (y < 0 || y >= rows) {
    return -1;
  }

  // Abbruch, wenn Wand
  if (a[x][y] == 'black' || a[x][y] == 'red' || a[x][y] == 'green') { // Wand
    return -1;
  }
  // Abbruch, wir sind nun am Ziel
  if (x == cols - 1 && y == rows - 1) {
    console.log('AM ZIEL!!!!');
    return 1;
  }

  // markiere momentanen Weg
  a[x][y] = 'green';

  // inform caller to paint a green cell
  postMessage({
    finished: -1,
    found: -1,
    element: 'green',
    yy: y,
    xx: x,
  });
  wait(slow);

  // suche einen Weg durch das Lab
  if (wayout(x, y - 1) == 1) { // top
    // a[x][y-1]= Color.red;
    return 1;
  } else if (wayout(x + 1, y) == 1) { // right
    // a[x+1][y]= Color.green;
    return 1;
  } else if (wayout(x, y + 1) == 1) { // bottom
    // a[x][y+1]= Color.red;
    return 1;
  } else if (wayout(x - 1, y) == 1) { // left
    // a[x-1][y]= Color.red;
    return 1;
  }

  // wenn wir bis hierher kommen gibts keinen weg
  a[x][y] = 'red';
  // inform caller for painting
  postMessage({
    finished: -1,
    found: -1,
    element: 'red',
    yy: y,
    xx: x,
  });
  wait(slow);

  return -1;
}

let wait = (ms) => {
  const start = new Date().getTime();
  let end = start;
  while (end < start + ms) {
    end = new Date().getTime();
  }
}