input mpchess

string pgnstr;
pgnstr:="1. e4 e5 2. Bc4 d6 3. Nf3 Bg4 4. Nc3 g6 5. Nxe5 Bxd1 ";
build_chessboards_from_pgn(pgnstr);

beginfig(0);
set_backboard_width(8cm);
init_backboard;
draw backboard;
show_last_move(10);
draw_comment("?","d1");
color_square(0.3[green,black])("c4","c3","e5");
color_square(0.3[red,black])("e8");
draw chessboard_step(10);
draw_arrows(0.3[green,black])("e5|-f7","c3-|d5");
draw_arrows(0.3[red,black])("c4--f7");
endfig;

end.

input geom2d;
% J.-M. Sarlat

labeloffset := 6;
gddU:=1.2cm;

vardef f(expr t) = 2*cos(t)*cos(t)*cos(t) enddef;
vardef g(expr t) = 2*sin(t)*sin(t)*sin(t) enddef;


beginfig(1);
 Repere(8,8,4,4,1.8,1.8);
 Axes; 
 Debut; 
  Graduations; Unites(1);
  drawoptions(withpen pencircle scaled 0.5 withcolor LightSlateGrey);
  trace ((-2,-2)--(-2,2)--(2,2)--(2,-2)--cycle);

  nb  = 80;
  pas = 2*Pi/nb;
  for i=0 upto nb: trace (0,2*sin(i*pas))--(2*cos(i*pas),0); endfor;

  fleche Segment((2,0),(1.2,0)) avecCrayon(1,RoyalBlue);
  fleche Segment((-2,0),(-1.2,0)) avecCrayon(1,RoyalBlue);
  fleche Segment((0,2),(0,1.2)) avecCrayon(1,RoyalBlue);
  fleche Segment((0,-2),(0,-1.2)) avecCrayon(1,RoyalBlue);

  trace Courbe(f,g,0,2*Pi,500) avecCrayon(1.5,DarkOrange);

  pointe Point(0,0);
  pointe Point(2,0);
  pointe Point(0,2);
  pointe Point(0,-2);
  pointe Point(-2,0);

 Fin;
endfig;
end

verbatimtex
%&latex
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[charter]{mathdesign}
\begin{document}
etex

input shadow;

beginfig(2);
  shadowdeg(btex Essai etex scaled 16, (4,-4),black,200);
  draw btex Essai etex scaled 16 withcolor blue withpen pencircle scaled 10pt;
endfig;

input metafun;

vardef shadowrect(expr dessin, vect,couleur) =
  save im,i;
  picture im;
  im := image(
    draw dessin;
    );
  draw im shifted vect withcolor couleur;
enddef;

vardef shadowblur(expr dessin, vect, couleur,pre,blur) =
  save im,i,t;
  picture im;
  im := image(
    draw dessin;
    );
  draw im shifted vect withcolor couleur;
  for i:=pre downto 0:
    for t:= 0 step 10 until 360:
      draw im shifted (vect+blur*i/pre*(sind(t),cosd(t))) withcolor transparent(1,0.5,((0.05,0.05,0.05)+couleur+(i)/pre*white));
    endfor;
  endfor;
enddef;

vardef shadowdeg(expr dessin, vect,couleur,pre) =
  save im,i;
  picture im;
  im := image(
    draw dessin;
    );
  for i:=pre downto 0:    
    draw im shifted ((i/pre)*vect) withcolor transparent(1,(10/(pre)*(pre-i)/pre),couleur);    
  endfor;
enddef;