[NTG-context] Reset environment between MetaPost graphics?

[Vincent Hennebert]

Hi,

Say I’m writing a document containing many independent MetaPost
figures. I don’t want to bother with enclosing each and every graphics
in a ‘begingroup...endgroup’ with the appropriate ‘save’ statement. But
I don’t want variables from previous graphics to leak into following
ones either.

Like this:

% SOF
\starttext

Text about some topic.

\startMPcode
u=1cm;
draw (-u, u)--origin--(u ,u);
\stopMPcode

Now on to another topic.

\startMPcode
u=2cm; % Triggers an error: Inconsistent equation (off by 28.34645)
draw (-u, u)..origin..(u ,u);
\stopMPcode

\stoptext
% EOF

Is that achievable?

Thanks,
Vincent