// Returns existing pair or creates a new one.
/// <summary>
/// Adds the pair using the specified proxy id 1
/// </summary>
/// <param name="proxyId1">The proxy id</param>
/// <param name="proxyId2">The proxy id</param>
/// <returns>The pair</returns>
private Pair AddPair(int proxyId1, int proxyId2)
{
if (proxyId1 > proxyId2)
{
Math.Swap(ref proxyId1, ref proxyId2);
}
int hash = (int)(Hash((uint)proxyId1, (uint)proxyId2) & TableMask);
Pair pair = Find(proxyId1, proxyId2, (uint)hash);
if (pair != null)
{
return(pair);
}
Box2DxDebug.Assert(PairCount < Settings.MaxPairs && FreePair != NullPair);
ushort pairIndex = FreePair;
pair = Pairs[pairIndex];
FreePair = pair.Next;
pair.ProxyId1 = (ushort)proxyId1;
pair.ProxyId2 = (ushort)proxyId2;
pair.Status = 0;
pair.UserData = null;
pair.Next = HashTable[hash];
HashTable[hash] = pairIndex;
++PairCount;
return(pair);
}
// Removes a pair. The pair must exist.
/// <summary>
/// Removes the pair using the specified proxy id 1
/// </summary>
/// <param name="proxyId1">The proxy id</param>
/// <param name="proxyId2">The proxy id</param>
/// <returns>The object</returns>
private object RemovePair(int proxyId1, int proxyId2)
{
Box2DxDebug.Assert(PairCount > 0);
if (proxyId1 > proxyId2)
{
Math.Swap(ref proxyId1, ref proxyId2);
}
int hash = (int)(Hash((uint)proxyId1, (uint)proxyId2) & TableMask);
//uint16* node = &m_hashTable[hash];
ushort node = HashTable[hash];
bool ion = false;
int ni = 0;
while (node != NullPair)
{
if (Equals(Pairs[node], proxyId1, proxyId2))
{
//uint16 index = *node;
//*node = m_pairs[*node].next;
ushort index = node;
node = Pairs[node].Next;
if (ion)
{
Pairs[ni].Next = node;
}
else
{
HashTable[hash] = node;
}
Pair pair = Pairs[index];
object userData = pair.UserData;
// Scrub
pair.Next = FreePair;
pair.ProxyId1 = NullProxy;
pair.ProxyId2 = NullProxy;
pair.UserData = null;
pair.Status = 0;
FreePair = index;
--PairCount;
return(userData);
}
//node = &m_pairs[*node].next;
ni = node;
node = Pairs[ni].Next;
ion = true;
}
Box2DxDebug.Assert(false);
return(null);
}
/// <summary>
/// Finds the proxy id 1
/// </summary>
/// <param name="proxyId1">The proxy id</param>
/// <param name="proxyId2">The proxy id</param>
/// <returns>The pair</returns>
private Pair Find(int proxyId1, int proxyId2)
{
if (proxyId1 > proxyId2)
{
Math.Swap(ref proxyId1, ref proxyId2);
}
uint hash = (uint)(Hash((uint)proxyId1, (uint)proxyId2) & TableMask);
return(Find(proxyId1, proxyId2, hash));
}