Game_Of_Life.pde

int virt_w, virt_h;
float scale;

int cells[][];
int cells_buf[][];

int COLS, ROWS;
int RESOLUTION;

long last_frame_time;
long tickout_time;

void settings()
{
  scale = 1.5;
  virt_w = floor(640 * scale);
  virt_h = floor(360 * scale);
  size(virt_w, virt_h);

  last_frame_time = 0;
  tickout_time = 200;

  RESOLUTION = 8;
  COLS = width / RESOLUTION;
  ROWS = height / RESOLUTION;

  cells = new int[COLS][ROWS];
  cells_buf = new int[COLS][ROWS];

  for (int i = 0; i < COLS; ++i) {
    for (int j = 0; j < ROWS; ++j) {
      if (random(1) > 0.65) cells[i][j] = 1;
      else cells[i][j] = 0; 
    }
  }
}

void draw()
{
  Update();
  Render();
}

void Update()
{
  long interval = millis() - last_frame_time;
  if (interval < tickout_time) return;

  for (int i = 0; i < (COLS * ROWS); ++i)
  {
    int count = CountNeighbours(i % COLS, i / COLS);
    println(count);
    if (cells[i % COLS][i / COLS] == 1 && (count < 2 || count > 3)) 
    {cells_buf[i % COLS][i / COLS] = 0;}
    if (cells[i % COLS][i / COLS] == 0 && count == 3)
    {cells_buf[i % COLS][i / COLS] = 1;}
  }

  arrayCopy(cells, cells_buf);
  last_frame_time = millis();
}

void Render()
{
  background(45);

  fill(244);
  for (int i = 0; i < (COLS * ROWS); ++i)
  {
    int x = i % COLS;
    int y = i / COLS;

    if (cells[x][y] == 0) continue;
    square(x * RESOLUTION, y * RESOLUTION, RESOLUTION);
  }
}

// TODO(rawxtl): 
// - Implement rules
// - Implement counting

int CountNeighbours(int x, int y)
{
 int count = 0;
 for (int i = 0; i < 3; ++i) {
   for (int j = 0; j < 3; ++j) {
     int nx = x - i;
     int ny = y - j;
     if (nx < 0 || nx > COLS || ny < 0 || ny > ROWS) continue;
     if (cells[nx][ny] == 1) count += 1;
   }
 } 
 return count > 0 ? count - 1: 0;
}