// GameSize = 10x10
  int gameSize = 100;
  Cell[][] c = new Cell[gameSize][gameSize];
  int fr = 10;
  int frames = 0;

  boolean isDraving = true;

  void setup() {
    size(400, 400);
    frameRate(30);
    noStroke();

    // random cells are alive
    for (int x = 0; x < gameSize; x++) {
      for (int y = 0; y < gameSize; y++) {
        c[x][y] = new Cell();
        if (random(1)< 0.05) {
          c[x][y].alive = true;
        }
      }
    }
  }

  void draw() {
    frames++;
    if (!isDraving) {
      if (frames % fr == 0) {
        for (int x = 0; x < gameSize; x++) {
          for (int y = 0; y < gameSize; y++) {

            // CALCULATE LIVING CELLES
            int lc = 0;
            try { // left upper
              if (c[x-1][y-1].alive == true) lc++;
            }
            catch(Exception e) {
            }

            try { //  upper
              if (c[x][y-1].alive == true) lc++;
            }
            catch(Exception e) {
            }

            try { // right upper
              if (c[x+1][y-1].alive == true) lc++;
            }
            catch(Exception e) {
            }

            try { // left
              if (c[x-1][y].alive == true) lc++;
            }
            catch(Exception e) {
            }

            try { // right
              if (c[x+1][y].alive == true) lc++;
            }
            catch(Exception e) {
            }

            try { // left down
              if (c[x-1][y+1].alive == true) lc++;
            }
            catch(Exception e) {
            }

            try { // down
              if (c[x][y-1].alive == true) lc++;
            }
            catch(Exception e) {
            }

            try { // right down
              if (c[x+1][y+1].alive == true) lc++;
            }
            catch(Exception e) {
            }

            if (lc > 0) println(lc);
            c[x][y].calculate(lc);

            // DRAW CELLES
            if (c[x][y].alive) {
              fill(255);
            } else {
              fill(0);
            }
            rect(width/gameSize*x, height/gameSize*y, width/gameSize, height/gameSize);
          }
          if (keyPressed) isDraving = true;
        }
      }
    } else {

      if (mousePressed) {
        int mx = floor( mouseX /(width/gameSize));
        int my = floor( mouseY /(width/gameSize));

        c[mx][my].alive = true;
      }

      if (keyPressed) isDraving = false;

      for (int x = 0; x < gameSize; x++) {
        for (int y = 0; y < gameSize; y++) {
          // DRAW CELLES
          if (c[x][y].alive) {
            fill(255);
          } else {
            fill(0);
          }
          rect(width/gameSize*x, height/gameSize*y, width/gameSize, height/gameSize);
        }
      }
    }
  }


  class Cell {
    boolean alive;

    void calculate(int lN) {
      if (lN == 3 || lN == 2) {
        // NOTHING ;D
        alive = true;
        //println("ALIVE");
      }
      if (lN < 2) {
        alive = false;
      }
      if (lN > 3) {
        alive = false;
      }
    }
  }