void clip(picture pic=currentpicture, path g, stroke=false, pen fillrule=currentpen);
Clip the current contents of picture
pic to the region bounded
by the path
g, using fill rule
fillrule (see fillrule).
stroke=true, the clipped portion is the same as the region
that would be drawn with
this case the path
g need not be cyclic. For an illustration of
picture clipping, see the first example in LaTeX usage.