gradient.getTransform().transform(rt, 0, rt, 0, 1);
trans.transform(rt, 0, rt, 0, 1);
centre = new Vector2f(c[0],c[1]);
Vector2f dis = new Vector2f(rt[0],rt[1]);
radius = dis.distance(centre);
}
/**
* @see org.newdawn.slick.geom.TexCoordGenerator#getCoordFor(float, float)
*/