/// <summary>
/// Adds a contact to the arbiter (threadsafe). No more than four contacts
/// are stored in the contactList. When adding a new contact
/// to the arbiter the existing are checked and the best are kept.
/// </summary>
/// <param name="point1">Point on body1. In world space.</param>
/// <param name="point2">Point on body2. In world space.</param>
/// <param name="normal">The normal pointing to body2.</param>
/// <param name="penetration">The estimated penetration depth.</param>
public Contact AddContact(FPVector point1, FPVector point2, FPVector normal, FP penetration,
ContactSettings contactSettings)
{
FPVector relPos1;
FPVector.Subtract(ref point1, ref body1.position, out relPos1);
int index;
lock (contactList)
{
if (this.contactList.Count == 4)
{
index = SortCachedPoints(ref relPos1, penetration);
ReplaceContact(ref point1, ref point2, ref normal, penetration, index, contactSettings);
return(null);
}
index = GetCacheEntry(ref relPos1, contactSettings.breakThreshold);
if (index >= 0)
{
ReplaceContact(ref point1, ref point2, ref normal, penetration, index, contactSettings);
return(null);
}
else
{
Contact contact = Contact.Pool.GetNew();
contact.Initialize(body1, body2, ref point1, ref point2, ref normal, penetration, true, contactSettings);
contactList.Add(contact);
return(contact);
}
}
}
private void ReplaceContact(ref FPVector point1, ref FPVector point2, ref FPVector n, FP p, int index,
ContactSettings contactSettings)
{
Contact contact = contactList[index];
Debug.Assert(body1 == contact.body1, "Body1 and Body2 not consistent.");
contact.Initialize(body1, body2, ref point1, ref point2, ref n, p, false, contactSettings);
}