float2 p1, float2 p2, float2 p3,
                               float2x2 matrix) {
    float m = wangs_formula_max_fdiff_p2(p0, p1, p2, p3, matrix);
    return ceil(log2(max(0.5625 * _precision_ * _precision_ * m, 1.0)) * .25);
}
float wangs_formula_conic_p2(float _precision_, float2 p0, float2 p1, float2 p2, float w) {
    // Translate the bounding box center to the origin.
    float2 C = (min(min(p0, p1), p2) + max(max(p0, p1), p2)) * 0.5;
    p0 -= C;
    p1 -= C;
    p2 -= C;

    // Compute max length.
    float m = sqrt(max(max(dot(p0,p0), dot(p1,p1)), dot(p2,p2)));

    // Compute forward differences.
    float2 dp = fma(float2(-2.0 * w), p1, p0) + p2;
    float dw = abs(fma(-2.0, w, 2.0));

    // Compute numerator and denominator for parametric step size of linearization. Here, the
    // epsilon referenced from the cited paper is 1/precision.
    float rp_minus_1 = max(0.0, fma(m, _precision_, -1.0));
    float numer = length(dp) * _precision_ + rp_minus_1 * dw;
    float denom = 4 * min(w, 1.0);

    return numer/denom;
}
float wangs_formula_conic(float _precision_, float2 p0, float2 p1, float2 p2, float w) {
    float n2 = wangs_formula_conic_p2(_precision_, p0, p1, p2, w);
    return max(ceil(sqrt(n2)), 1.0);
}
float wangs_formula_conic_log2(float _precision_, float2 p0, float2 p1, float2 p2, float w) {
    float n2 = wangs_formula_conic_p2(_precision_, p0, p1, p2, w);
    return ceil(log2(max(n2, 1.0)) * .5);
}