[求助] 如何得到相邻的C_UDMI？

{
c_face_loop(c,t,n)
{ f= C_FACE(c,t,n);
tf= C_FACE_THREAD(c,t,n);
F_AREA(A,f,tf);
c0= F_C0(f,tf); c1= F_C1(f,tf); t0= THREAD_T0(tf); t1= THREAD_T1(tf); C_CENTROID(xx,c0,t0);
C_CENTROID(y,c1,t1);
}
}