roseRingsetCF might be defined something like?
roseRingsetCF=Compile[{{\[Theta], _Real},{r, _Real},{\[Theta]0, _Real},{d, _Real},{n, _Integer},{\[Alpha], _Real}},Module[{t1,t2},(*2 part composite curve*)t1=Sec[2 ArcTan[Cot[n (\[Theta]-\[Theta]0)/2]]/n];
t2=Sec[\[Alpha]] Sqrt[-d^2+r^2+2 d Cos[\[Pi]/n] t1 Sin[\[Theta]]-Cos[\[Pi]/n]^2 t1^2 Sin[\[Theta]]^2];
{(*part1*)roseRing1CF[\[Theta],r,\[Theta]0,d,n,\[Alpha],t1,t2],(*part 2*)roseRing2CF[\[Theta],r,\[Theta]0,d,n,\[Alpha],t1,t2]}]];
Michael