js-tetris - lines and level

board.js

if (lines > 0) {
  // Calculate points from cleared lines and level.
  
  account.score += this.getLinesClearedPoints(lines, this.level);
  account.lines += lines;
  
  // If we have reached the lines for next level
  if (account.lines >= LINES_PER_LEVEL) {
    
    // Goto next level
    account.level++;
    
    // Remove lines so we start working for the next level
    account.lines -= LINES_PER_LEVEL;
    
    // Increase speed of game.
    time.level = Level[account.level];
  }
}