private XVector3 BisectionSearch(XVector3 origin, XVector3 end, float min, float max)
{
float mid = (min + max) / 2;
XVector3 newEnd = end + mid * XVector3.Normalize(end - origin);
float minDot = float.MaxValue;
for (int i = 0; i < _verts.Length; i++)
{
float dot = XVector3.Dot(XVector3.Normalize(origin - newEnd), XVector3.Normalize(_verts[i] - newEnd));
if (dot < -_Epsilon)
{
return(BisectionSearch(origin, end, mid, max));
}
if (minDot > dot)
{
minDot = dot;
}
}
if (minDot > _Epsilon)
{
return(BisectionSearch(origin, end, min, mid));
}
return(newEnd);
}
private void GetReferencePoint()
{
bool assigned = false;
float min = float.MaxValue;
var ji = XVector3.Normalize(_verts[0] - _verts[1]);
var jk = XVector3.Normalize(_verts[2] - _verts[1]);
var kl = XVector3.Normalize(_verts[3] - _verts[2]);
var il = XVector3.Normalize(_verts[3] - _verts[0]);
var ij = -ji;
var kj = -jk;
var lk = -kl;
var li = -il;
float[] dots = { XVector3.Dot(ij, il), XVector3.Dot(ji, jk),
XVector3.Dot(kj, kl), XVector3.Dot(lk, li) };
for (int n = 0; n < dots.Length; n++)
{
if (dots[n] > -_Epsilon && min > dots[n] && (dots[(n + 3) % dots.Length] > -_Epsilon ||
dots[(n + 1) % dots.Length] > -_Epsilon))
{
assigned = true;
Start = _verts[n];
Corner = _verts[(n + 1) % dots.Length];
min = dots[n];
}
}
if (!assigned)
{
Start = _verts[0];
Corner = _verts[1];
}
}
private int ExponentialSearch(XVector3 origin, XVector3 end, int step = -1)
{
var newEnd = end + Exp(step) * XVector3.Normalize(end - origin);
for (int i = 0; i < _verts.Length; i++)
{
float dot = XVector3.Dot(XVector3.Normalize(origin - newEnd), XVector3.Normalize(_verts[i] - newEnd));
if (dot < 0)
{
return(ExponentialSearch(origin, end, step + 1));
}
}
return(step);
}