Clipping a 2D plot

edit

Dear all,

Best is a small example:

def fC(p):
    return([p[0]/(p[0]+2), (p[1]+1)/(p[0]+2)])

def actOnD(Dom, nbsteps, myz):
    DomainfC = list(map(fC, Dom))
    acolor = Color(0, (20+90*nbsteps)/255, 150/255) 
    ToPlot = polygon(Dom, color = acolor, zorder = myz)
    if nbsteps > 0:
        DomainfC = list(map(fC, Dom))
        ToPlot += actOnD(DomainfC, nbsteps-1, myz+1)
    return(ToPlot)

actOnD( [[0,0], [0,1], [1,1], [1,0]], 3, 1)

And I would like to show only the plot within a smaller square than the unit one. It seems add_conditions works for parametric plot (though I did not find the documentatin for that, only posts). Many thanks for your lights on that!

Best, Olivier