\documentclass{standalone}

\usepackage{tikz}
\usepackage{shapes}

\begin{document}
\begin{tikzpicture}

  \clip(-2,6)--++(12,0)--++(0,12)--++(-12,0);

  \grid{19}{24}{(-6,-1)}
  \foreach\x in {0,...,6}{
    \foreach\y in {0,...,6}{
      \staircase{cyan}{(2*\x-\y,\x+3*\y)}
    }
  }

\end{tikzpicture}
\end{document}