[NTG-context] draw & fill

[Taco Hoekwater]

Hi Peter,

>   def draw_vline(expr h,a,b,c)=
>     draw (.5u,.5u)--(.5u,h*u-.5u) withpen pensquare scaled u

That scales the whole draw statement, just like if you had said:

      draw (.5u,.5u)--(.5u,h*u-.5u) scaled u withpen pensquare

So you need to do it like this:

     draw (.5u,.5u)--(.5u,h*u-.5u) withpen (pensquare scaled u)

Cheers, Taco