\documentclass{article}\begin{document}\directlua{

function p(h,w,t)

for i=1,h do tex.print("\\centerline{"..("*"):rep(2*i-1).."}")end

for i=1,t do tex.print("\\centerline{"..("*"):rep(w).."}")end

tex.print("\\centerline{Merry Xmas}")

end}\def\P#1,#2,#3{\directlua{p(#1,#2,#3)}}\P30,5,7\end{document} https://bsky.app/profile/dfaria.eu/post/3mansve3ii22k