45 def calcCubicBounds(pt1, pt2, pt3, pt4):  argument
56     (ax, ay), (bx, by), (cx, cy), (dx, dy) = calcCubicParameters(pt1, pt2, pt3, pt4)
66 … = [(ax*t*t*t + bx*t*t + cx * t + dx, ay*t*t*t + by*t*t + cy * t + dy) for t in roots] + [pt1, pt4]
141 def splitCubic(pt1, pt2, pt3, pt4, where, isHorizontal):  argument
156     a, b, c, d = calcCubicParameters(pt1, pt2, pt3, pt4)
161         return [(pt1, pt2, pt3, pt4)]
181 def splitCubicAtT(pt1, pt2, pt3, pt4, *ts):  argument
193     a, b, c, d = calcCubicParameters(pt1, pt2, pt3, pt4)
244         pt1, pt2, pt3, pt4 = calcCubicPoints((a1x, a1y), (b1x, b1y), (c1x, c1y), (d1x, d1y))
245         segments.append((pt1, pt2, pt3, pt4))
341 def calcCubicParameters(pt1, pt2, pt3, pt4):  argument
344     x4, y4 = pt4