help I need answers to this too. What I've tried doing is the tile way. since it takes 8 tiles to complete a 'circle' at 1 radius, i did something like:

radius= 10;

r= 0;

offset= 360/(r * 8);

i= i+offset;

if i===360, r+1;

if r===radius, r=0;

posx= sin(i)*r+originx;

posy= cos(i)*r+originy;