swarm

in AddRing:

int     swcnt;  // number of vertices in swarm polygon
int     swidx;  // index of swarm polygon's current vertex
int     swrad;  // radius of swarm polygon, in pixels

double  theta = (PI * 2) * (double(swidx) / swcnt);     // can be better optimized
Ring.Shift.x += sin(theta) * swrad;
Ring.Shift.y += cos(theta) * swrad;
swidx++;
swidx %= swcnt;         // can be better optimized

NOTE that this feature requires the skew curve fix (see above), otherwise curves will be horribly distorted.