I have a cubic Bezier curve which has a width, and I am trying to align another cubic Bezier curve around the outside of it. This is hard to explain in text, so please see the following image:
Clearly, just translating the curve doesn't work (this should be obvious, as the curvature on the outside of the curve is larger than that on the inside).
Is there any way to mathematically find the points which define the blue cubic Bezier curve in the goal image, from the red one? I.e. the input is cubic Bezier control points $p_0, p_1, p_2, p_3$ and a line width $w$, and the output is cubic Bezier control points $p_0', p_1', p_2', p_3'$ which define the second curve. The example given has the curve at right angles but ideally this would work for any 'concave' Bezier curve.
