From 80f22a9e602c40eca5c7f8a9a7b5b8b291b51bff Mon Sep 17 00:00:00 2001
From: Erwin Coumans <blender@erwincoumans.com>
Date: Wed, 17 Sep 2008 20:02:20 +0000
Subject: added another missing file, btHashMap

---
 extern/bullet2/src/LinearMath/btHashMap.h | 303 ++++++++++++++++++++++++++++++
 1 file changed, 303 insertions(+)
 create mode 100644 extern/bullet2/src/LinearMath/btHashMap.h

(limited to 'extern')

diff --git a/extern/bullet2/src/LinearMath/btHashMap.h b/extern/bullet2/src/LinearMath/btHashMap.h
new file mode 100644
index 00000000000..f883e0e489a
--- /dev/null
+++ b/extern/bullet2/src/LinearMath/btHashMap.h
@@ -0,0 +1,303 @@
+#ifndef BT_HASH_MAP_H
+#define BT_HASH_MAP_H
+
+#include "btAlignedObjectArray.h"
+
+const int BT_HASH_NULL=0xffffffff;
+
+template <class Value>
+class btHashKey
+{
+	int	m_uid;
+public:
+
+	btHashKey(int uid)
+		:m_uid(uid)
+	{
+	}
+
+	int	getUid() const
+	{
+		return m_uid;
+	}
+
+	//to our success
+	SIMD_FORCE_INLINE	unsigned int getHash()const
+	{
+		int key = m_uid;
+		// Thomas Wang's hash
+		key += ~(key << 15);
+		key ^=  (key >> 10);
+		key +=  (key << 3);
+		key ^=  (key >> 6);
+		key += ~(key << 11);
+		key ^=  (key >> 16);
+		return key;
+	}
+
+	btHashKey	getKey(const Value& value) const
+	{
+		return btHashKey(value.getUid());
+	}
+};
+
+
+template <class Value>
+class btHashKeyPtr
+{
+	int	m_uid;
+public:
+
+	btHashKeyPtr(int uid)
+		:m_uid(uid)
+	{
+	}
+
+	int	getUid() const
+	{
+		return m_uid;
+	}
+
+	//to our success
+	SIMD_FORCE_INLINE	unsigned int getHash()const
+	{
+		int key = m_uid;
+		// Thomas Wang's hash
+		key += ~(key << 15);
+		key ^=  (key >> 10);
+		key +=  (key << 3);
+		key ^=  (key >> 6);
+		key += ~(key << 11);
+		key ^=  (key >> 16);
+		return key;
+	}
+
+	btHashKeyPtr	getKey(const Value& value) const
+	{
+		return btHashKeyPtr(value->getUid());
+	}
+};
+
+///The btHashMap template class implements a generic and lightweight hashmap.
+///A basic sample of how to use btHashMap is located in Demos\BasicDemo\main.cpp
+template <class Key, class Value>
+class btHashMap
+{
+
+	btAlignedObjectArray<int>		m_hashTable;
+	btAlignedObjectArray<int>		m_next;
+	btAlignedObjectArray<Value>		m_valueArray;
+
+
+
+	void	growTables(const Key& key)
+	{
+		int newCapacity = m_valueArray.capacity();
+
+		if (m_hashTable.size() < newCapacity)
+		{
+			//grow hashtable and next table
+			int curHashtableSize = m_hashTable.size();
+
+			m_hashTable.resize(newCapacity);
+			m_next.resize(newCapacity);
+
+			int i;
+
+			for (i= 0; i < newCapacity; ++i)
+			{
+				m_hashTable[i] = BT_HASH_NULL;
+			}
+			for (i = 0; i < newCapacity; ++i)
+			{
+				m_next[i] = BT_HASH_NULL;
+			}
+
+			for(i=0;i<curHashtableSize;i++)
+			{
+				const Value& value = m_valueArray[i];
+
+				int	hashValue = key.getKey(value).getHash() & (m_valueArray.capacity()-1);	// New hash value with new mask
+				m_next[i] = m_hashTable[hashValue];
+				m_hashTable[hashValue] = i;
+			}
+
+
+		}
+	}
+
+	public:
+
+	void insert(const Key& key, const Value& value) {
+		int hash = key.getHash() & (m_valueArray.capacity()-1);
+		//don't add it if it is already there
+		if (find(key))
+		{
+			return;
+		}
+		int count = m_valueArray.size();
+		int oldCapacity = m_valueArray.capacity();
+		m_valueArray.push_back(value);
+		int newCapacity = m_valueArray.capacity();
+		if (oldCapacity < newCapacity)
+		{
+			growTables(key);
+			//hash with new capacity
+			hash = key.getHash() & (m_valueArray.capacity()-1);
+		}
+		m_next[count] = m_hashTable[hash];
+		m_hashTable[hash] = count;
+	}
+
+	void remove(const Key& key) {
+
+		int hash = key.getHash() & (m_valueArray.capacity()-1);
+
+		int pairIndex = findIndex(key);
+		
+		if (pairIndex ==BT_HASH_NULL)
+		{
+			return;
+		}
+
+		// Remove the pair from the hash table.
+		int index = m_hashTable[hash];
+		btAssert(index != BT_HASH_NULL);
+
+		int previous = BT_HASH_NULL;
+		while (index != pairIndex)
+		{
+			previous = index;
+			index = m_next[index];
+		}
+
+		if (previous != BT_HASH_NULL)
+		{
+			btAssert(m_next[previous] == pairIndex);
+			m_next[previous] = m_next[pairIndex];
+		}
+		else
+		{
+			m_hashTable[hash] = m_next[pairIndex];
+		}
+
+		// We now move the last pair into spot of the
+		// pair being removed. We need to fix the hash
+		// table indices to support the move.
+
+		int lastPairIndex = m_valueArray.size() - 1;
+
+		// If the removed pair is the last pair, we are done.
+		if (lastPairIndex == pairIndex)
+		{
+			m_valueArray.pop_back();
+			return;
+		}
+
+		// Remove the last pair from the hash table.
+		const Value* lastValue = &m_valueArray[lastPairIndex];
+		int lastHash = key.getKey(*lastValue).getHash() & (m_valueArray.capacity()-1);
+
+		index = m_hashTable[lastHash];
+		btAssert(index != BT_HASH_NULL);
+
+		previous = BT_HASH_NULL;
+		while (index != lastPairIndex)
+		{
+			previous = index;
+			index = m_next[index];
+		}
+
+		if (previous != BT_HASH_NULL)
+		{
+			btAssert(m_next[previous] == lastPairIndex);
+			m_next[previous] = m_next[lastPairIndex];
+		}
+		else
+		{
+			m_hashTable[lastHash] = m_next[lastPairIndex];
+		}
+
+		// Copy the last pair into the remove pair's spot.
+		m_valueArray[pairIndex] = m_valueArray[lastPairIndex];
+
+		// Insert the last pair into the hash table
+		m_next[pairIndex] = m_hashTable[lastHash];
+		m_hashTable[lastHash] = pairIndex;
+
+		m_valueArray.pop_back();
+
+	}
+
+
+	int size() const
+	{
+		return m_valueArray.size();
+	}
+
+	const Value* getAtIndex(int index) const
+	{
+		btAssert(index < m_valueArray.size());
+
+		return &m_valueArray[index];
+	}
+
+	Value* getAtIndex(int index)
+	{
+		btAssert(index < m_valueArray.size());
+
+		return &m_valueArray[index];
+	}
+
+	Value* operator[](const Key& key) {
+		return find(key);
+	}
+
+	const Value*	find(const Key& key) const
+	{
+		int index = findIndex(key);
+		if (index == BT_HASH_NULL)
+		{
+			return NULL;
+		}
+		return &m_valueArray[index];
+	}
+
+	Value*	find(const Key& key)
+	{
+		int index = findIndex(key);
+		if (index == BT_HASH_NULL)
+		{
+			return NULL;
+		}
+		return &m_valueArray[index];
+	}
+
+
+	int	findIndex(const Key& key) const
+	{
+		int hash = key.getHash() & (m_valueArray.capacity()-1);
+
+		if (hash >= m_hashTable.size())
+		{
+			return BT_HASH_NULL;
+		}
+
+		int index = m_hashTable[hash];
+		while ((index != BT_HASH_NULL) && (key.getUid() == key.getKey(m_valueArray[index]).getUid()) == false)
+		{
+			index = m_next[index];
+		}
+		return index;
+	}
+
+	void	clear()
+	{
+		m_hashTable.clear();
+		m_next.clear();
+		m_valueArray.clear();
+	}
+
+};
+
+#endif //BT_HASH_MAP_H
-- 
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