def rot_points(pnts, pb, alfa):
points = []                   <EOL>calfa = math.cos(alfa)<EOL>salfa = math.sin(alfa)<EOL>for p in pnts:<EOL><INDENT>s = p - pb<EOL>r = abs(s)<EOL>if r > <NUM_LIT:0>: s /= r<EOL>np = (s.x * calfa - s.y * salfa, s.y * calfa + s.x * salfa)<EOL>points.append(pb + fitz.Point(np)*r)<EOL><DEDENT>return points<EOL>
Rotate a list of points by an angle alfa (radians) around pivotal point pb.
    Intended for modifying the control points of trigonometric functions.