Incircle test for weighted vertices

Hi, first of all thanks for the great work of bringing the robust predicates to rust ! 👏🏻

I would like to advance the incircle test to work with weighted vertices, i.e. each vertex has an associated weight.
So for a given triangle $a, b, c$ and a vertex $v$ to test, the general test:

$$
incircle(triangle, v) = det
\begin{bmatrix}
a_x & a_y & a_x^2 + a_y^2 & 1 \\
b_x & b_y & b_x^2 + b_y^2 & 1 \\
c_x & c_y & c_x^2 + c_y^2 & 1 \\
v_x & v_y & v_x^2 + v_y^2 & 1 \\
\end{bmatrix} = det
\begin{bmatrix}
a_x - v_x & a_y - v_y & (a_x - v_x)^2 + (a_y - v_y)^2 \\
b_x - v_x & b_y - v_y & (b_x - v_x)^2 + (b_y - v_y)^2 \\
c_x - v_x & c_y - v_y & (c_x - v_x)^2 + (c_y - v_y)^2 \\
\end{bmatrix}
$$

becomes this one (substracting the weights from the sum):

$$
inpowercircle(triangle, v) = det
\begin{bmatrix}
a_x & a_y & a_x^2 + a_y^2 - a_w & 1 \\
b_x & b_y & b_x^2 + b_y^2 - b_w & 1 \\
c_x & c_y & c_x^2 + c_y^2 - c_w & 1 \\
v_x & v_y & v_x^2 + v_y^2 - v_w & 1 \\
\end{bmatrix}
$$

$$
= det \begin{bmatrix}
a_x - v_x & a_y - v_y & (a_x - v_x)^2 + (a_y - v_y)^2 - w_a + w_v \\
b_x - v_x & b_y - v_y & (b_x - v_x)^2 + (b_y - v_y)^2 - w_b + w_v \\
c_x - v_x & c_y - v_y & (c_x - v_x)^2 + (c_y - v_y)^2 - w_c + w_v \\
\end{bmatrix}
$$

My questions is: since the change in the matrix determinant is rather small, one substraction and addition per line, can you estimate how easily this could be incorporated into the algorithm?
I already scanned the code and saw the places for the lifting (lines 589 to 600) in `incircle()`, but I can not really see how this translates into `incircleadapt()`.

Thanks for your help in advance!