创建圆顶屋顶(Round)。
roofRound(height, angle)
attr x = roofRound(height, angle)
@StartRule
Lot --> primitiveDisk(16, 4)
extrude(4)
comp(f) { top: Roof | side: Wall }
Roof --> roofRound(30)
color(0.5, 0.25, 0.15)
Wall --> color(0.75, 0.72, 0.68)