\documentclass{standalone}
\usepackage{luamplib}
\begin{document}
\mplibtextextlabel{enable}
\begin{mplibcode}
input colorbrewer-rgb
vardef pinwheel(expr level, a, b, c, s) = 
    if level = 0:
        fill a--b--c--cycle withcolor s;
        draw a--b--c--cycle withpen pencircle scaled 1/16 withcolor Blues 9 1;
        % path t; t = a--b--9/10[b,c]--cycle;
        % fill t withcolor s;
        % draw t withpen pencircle scaled 1/16 withcolor Greens 9 1;
        % draw point 5/2 of t withpen pencircle scaled 2 withcolor (1/4 + greenpart s, redpart s, bluepart s);
    else:
        save d, e, f, g;
        pair d, e, f, g; 
        d = 2/5[b, c]; e = 4/5[b,c]; f = 1/2[e, a]; g = 1/2[a, b];
        pinwheel(level - 1, e, a, c, Blues 9 4);
        pinwheel(level - 1, f, g, a, Blues 9 3);
        pinwheel(level - 1, f, g, e, Blues 9 2);
        pinwheel(level - 1, d, e, g, Blues 9 5);
        pinwheel(level - 1, d, b, g, Blues 9 6);
    fi
enddef;
beginfig(1);
    numeric a, b; b = 6.4in; 2a = b; 
    pinwheel(5, (0, 0), (b, 0), (0, a), ""); 
    pinwheel(5, (b, a), (0, a), (b, 0), "");
    currentpicture := currentpicture rotated 90;
    % for i=1 upto 1:
    %     draw currentpicture shifted (lrcorner currentpicture - llcorner currentpicture);
    % endfor
endfig;
\end{mplibcode}
\end{document}