verbatimtex
\documentclass[12pt]{article}

% \usepackage[mathlf,minionint]{MinionPro} \usepackage[T1]{fontenc} \usepackage{textcomp}

\begin{document}
etex

def whiteCircle(expr p, b) =
begingroup
	fill fullcircle scaled b shifted p withcolor white;
	draw fullcircle scaled b shifted p;
endgroup
enddef;

def blackCircle(expr p, b) =
begingroup
	draw p withpen pencircle scaled b;
endgroup
enddef;

vardef TEX primary s =
   write "verbatimtex"                    to "mptextmp.mp";
   write "\documentclass[12pt]{article}"  to "mptextmp.mp";
   %write "\usepackage[T1]{fontenc}"       to "mptextmp.mp";
   %write "\usepackage{amsmath,amssymb}"   to "mptextmp.mp";
   write "\begin{document}"               to "mptextmp.mp";
   write "etex"                           to "mptextmp.mp";
   write "btex "&s&" etex"                to "mptextmp.mp";
   write EOF                              to "mptextmp.mp";
   scantokens "input mptextmp"
enddef;

beginfig(1)
	u := 1.7cm;

	picture hexagon;
	hexagon := nullpicture;

	pair A[], B[];
	numeric n; n:=6;

	for i=0 upto n-1:
		A[i] = u * right rotated (i*360/n);
	endfor;
	A[n] = A[0];

	% Shading of positive triangles.
	addto hexagon contour (0,0) -- A[1] -- A[2] -- cycle withcolor 0.9white;
	addto hexagon contour (0,0) -- A[3] -- A[4] -- cycle withcolor 0.9white;
	addto hexagon contour (0,0) -- A[5] -- A[6] -- cycle withcolor 0.9white;

	for i=0 upto n-1:
		addto hexagon doublepath A[i] -- A[i+1];
	endfor;
	
	addto hexagon doublepath A[0] -- A[3] withcolor 0.7white;
	addto hexagon doublepath A[1] -- A[4] withcolor 0.7white;
	addto hexagon doublepath A[2] -- A[5] withcolor 0.7white;

	addto hexagon contour fullcircle scaled 4bp    shifted A[1] withcolor white;
	addto hexagon doublepath fullcircle scaled 4bp shifted A[1];
	addto hexagon contour fullcircle scaled 4bp    shifted A[3] withcolor white;
	addto hexagon doublepath fullcircle scaled 4bp shifted A[3];
	addto hexagon contour fullcircle scaled 4bp    shifted A[5] withcolor white;
	addto hexagon doublepath fullcircle scaled 4bp shifted A[5];

	addto hexagon doublepath (0,0) withpen pencircle scaled 4bp;
	%addto hexagon doublepath A[0] withpen pencircle scaled 4bp;
	%addto hexagon doublepath A[2] withpen pencircle scaled 4bp;
	%addto hexagon doublepath A[4] withpen pencircle scaled 4bp;
	%addto hexagon also TEX("$\star$");

	pair hexUpRight, hexDown, hexRight, hexDownRight;
	hexUpRight := A[1] + A[0];
	hexDown := A[4] + A[5];
	hexRight := A[0];
	hexDownRight := A[0] + A[5];

	draw hexagon;
	draw hexagon shifted hexDown;
	draw hexagon shifted hexDownRight;

	label(TEX("$\star$"), A[0]);
	label(TEX("$\star$"), A[2]);
	label(TEX("$\star$"), A[4]);

	label(TEX("$\star$"), A[0]) shifted hexDown;
	label(TEX("$\star$"), A[0]) shifted hexDownRight;
	label(TEX("$\star$"), A[4]) shifted hexDown;

	pair triangleTop, triangleLL, triangleLR;
	triangleTop := 1/2[(0, 0), (1/2[A[1], A[2]])];
	triangleLL := 1/2[(0, 0), (1/2[A[3], A[4]])];
	triangleLR := 1/2[(0, 0), (1/2[A[5], A[6]])];

	label.top(btex $r$ etex, triangleTop) shifted A[5];
	label.llft(btex $s$ etex, triangleLL) shifted A[5];
	label.lrt(btex $t$ etex, triangleLR)  shifted A[5];

endfig;



end