public static float Detect(Quad obstacle, Player player)
{
var tr = FixedTransformation(obstacle);
var q = (tr * Vector4.UnitW).Xyz;
var p = player.GetPosition();
var n = obstacle.GetNormal();
var qp = p - q;
var sgnd = Vector3.Dot(qp, n);
var r = -sgnd * n + p;
var w = (tr * new Vector4(obstacle.GetWidth(), obstacle.GetHeight(), 0f, 1.0f)).Xyz;
var cmpR = new Vector3(FixedClamp(r.X, q.X, w.X), FixedClamp(r.Y, q.Y, w.Y), FixedClamp(r.Z, q.Z, w.Z));
var cmpRP = p - cmpR;
var diff = cmpRP.Length - player.GetRadius();
return(diff);
}
