% trebuchet.mp % L. Nobre G. % 2014 %prologues := 1; %outputformat := "png"; %outputformatoptions := "format=rgb antialias=best"; %hppp := 0.25; %vppp := 0.25; beginfig(1); numeric i, s, a, u, h, t; pair pi, pj, pk; u = 9mm; h = 5u; a = 0.039u; s = 5; draw (0,-h) for i=s-90 step s until 90: ..(h*(2*cosd(i),sind(i))) endfor --cycle; draw origin--(2h,0); t = 0; forever: t := incr(t); i := h-0.5*a*t**2; exitif i<-h; pi := (0,i); pj := (h+-+i,0); pk := 2[pi,pj]; if i<0: draw pj withpen pencircle scaled 0.17u; fi; draw pi--pk withcolor 0.5white; endfor; endfig; end.