All, I'm looking for a new idea for something I need to do. I typically create a path on a domain [-5,5] as follows, a arbitrary. Then I randomly reflect the path about and axis, a line, or maybe rotate it. The result is that parts of the path may lie outside a bounding window. % define linear function f vardef f(expr x)= a*x*x enddef; % define paths for functions f, g, and h, respectively path P; P:=(-5,f(-5)); for x=-5 step .1 until 5: P:=P--(x,f(x)); endfor; % initialize scale numeric u; 10u=w; % scale and draw graph P:=P scaled u; draw P withcolor blue; % clipping path path cpath; cpath:=(-5,-5)--(5,-5)--(5,5)--(-5,5)--cycle; cpath:=cpath scaled 1u; % clip and save current picture picture pic; clip currentpicture to cpath; pic:=currentpicture; % erase currentpicture currentpicture:=nullpicture; Then I do some stuff I need to do and bring back the path at a later time with: draw pic; This works fine. However, what I need to do is somehow clip the path P to the bounding box, but retain the resulting cutpath in a path variable Q. That is, I need to cut off the parts of the path P that lie outside the bounding box cpath:=(-5,-5)--(5,-5)--(5,5)--(-5,5)--cycle and store the clipped path in the path variable Q. The difficulty is I have no advance knowledge if the path P lies entirely inside the bounding box or if it escapes through one of the sides. Any hints, tips, etc., would be very appreciated. Thanks.