//TODO: Having a specialized triangle-triangle pair test would be nice. Even if it didn't use an actual triangle-triangle test, certain assumptions could still make it speedier and more elegant.
//"Closest points between triangles" + persistent manifolding would probably be the best approach (a lot faster than the triangle-convex general case anyway).
public override bool GenerateContactCandidate(out DataStructures.TinyStructList<ContactData> contactList)
{
if (base.GenerateContactCandidate(out contactList))
{
//The triangle-convex pair test has already rejected contacts whose normals would violate the first triangle's sidedness.
//However, since it's a vanilla triangle-convex test, it doesn't know about the sidedness of the other triangle!
var shape = ((TriangleShape)convex);
Vector3 normal;
//Lots of recalculating ab-bc!
Vector3 ab, ac;
Vector3.Subtract(ref shape.vB, ref shape.vA, out ab);
Vector3.Subtract(ref shape.vC, ref shape.vA, out ac);
Vector3.Cross(ref ab, ref ac, out normal);
var sidedness = shape.sidedness;
if (sidedness != TriangleSidedness.DoubleSided)
{
for (int i = contactList.count - 1; i >= 0; i--)
{
ContactData item;
contactList.Get(i, out item);
float dot;
Vector3.Dot(ref item.Normal, ref normal, out dot);
if (sidedness == TriangleSidedness.Clockwise)
{
if (dot < 0)
{
contactList.RemoveAt(i);
}
}
else
{
if (dot > 0)
{
contactList.RemoveAt(i);
}
}
}
}
return contactList.count > 0;
}
return false;
}
