public void GetSearchDirection(Vec2 result)
{
switch (Count)
{
case 1:
result.Set(m_v1.W).NegateLocal();
return;
case 2:
e12.Set(m_v2.W).SubLocal(m_v1.W);
// use out for a temp variable real quick
result.Set(m_v1.W).NegateLocal();
float sgn = Vec2.Cross(e12, result);
if (sgn > 0f)
{
// Origin is left of e12.
Vec2.CrossToOutUnsafe(1f, e12, result);
return;
}
else
{
// Origin is right of e12.
Vec2.CrossToOutUnsafe(e12, 1f, result);
return;
}
default:
Debug.Assert(false);
result.SetZero();
return;
}
}
/// <summary>
/// Set this to the identity transform.
/// </summary>
public void SetIdentity()
{
P.SetZero();
Q.SetIdentity();
}
/// <summary>
/// this returns pooled objects. don't keep or modify them
/// </summary>
/// <returns></returns>
public void GetClosestPoint(Vec2 result)
{
switch (Count)
{
case 0:
Debug.Assert(false);
result.SetZero();
return;
case 1:
result.Set(m_v1.W);
return;
case 2:
case22.Set(m_v2.W).MulLocal(m_v2.A);
case2.Set(m_v1.W).MulLocal(m_v1.A).AddLocal(case22);
result.Set(case2);
return;
case 3:
result.SetZero();
return;
default:
Debug.Assert(false);
result.SetZero();
return;
}
}
