Function stVec2Qt

src/Sato/stMath.cpp:248–267

}

bool stVec2Qt(Quaternion &q, const Vec &dir, const Vec &vec)
{
    Vec cross;
    bool ret = false;
    PSVECCrossProduct(&dir, &vec, &cross);
    float dot = PSVECDotProduct(&dir, &vec);

    float length = stspeedy_sqrtf(2.0f * (1.0f + dot));

    if (length > 0.0f)
    {
        q.x = cross.x / length;
        q.y = cross.y / length;
        q.z = cross.z / length;
        q.w = 0.5f * length;
        ret = true;
    }

    return ret;
}

// TODO: match it in a way that makes sense
// https://decomp.me/scratch/2u8r1