Mesh in polar coordinates

Suppose we have a domain in polar coordinates with boundary r=f(theta). 0<=theta<=2*pi. How to build a mesh in FreeFem++. Can I use movemesh in polar to polar transformation from (r , theta) coordinates to (r’ , theta’) coordinates. This FreeFem++ is far better than MatLab for FEMians. Any suggestion regarding this will be a great help.
Thank you!

Just do like a circle mesh:

func real f(real t){ return 1+0.1*cos(t);}
border bf(t=0,2*pi){ x=f(t)*cos(t);y=f(t)*sin(t}:
mesh Th=buildmesh(bf(30));

What about transformation of mesh from polar (r , theta) to polar (r’ , theta’). How to use movemesh ?

pass trough x,y coordinate