move body handles in its own template class, for re-use.

src/Bullet3Common/b3ResizablePool.h

@@ -0,0 +1,130 @@
+
+#ifndef B3_RESIZABLE_POOL_H
+#define B3_RESIZABLE_POOL_H
+
+#include "Bullet3Common/b3AlignedObjectArray.h"
+
+template <typename U>
+struct b3PoolBodyHandle : public U
+{
+	BT_DECLARE_ALIGNED_ALLOCATOR();
+
+	int m_nextFreeHandle;
+	void SetNextFree(int next)
+	{
+		m_nextFreeHandle = next;
+	}
+	int	GetNextFree() const
+	{
+		return m_nextFreeHandle;
+	}
+};
+
+template <typename T> 
+class b3ResizablePool
+{
+
+protected:
+	b3AlignedObjectArray<T>	m_bodyHandles;
+	int m_numUsedHandles;						// number of active handles
+	int	m_firstFreeHandle;		// free handles list
+
+public:
+	
+	b3ResizablePool()
+	{
+	}
+	
+	virtual ~b3ResizablePool()
+	{
+	}
+///handle management
+
+	int getNumHandles() const
+	{
+		return m_bodyHandles.size();
+	}
+
+	T* getHandle(int handle)
+	{
+		btAssert(handle>=0);
+		btAssert(handle<m_bodyHandles.size());
+		if ((handle<0) || (handle>=m_bodyHandles.size()))
+		{
+			return 0;
+		}
+		return &m_bodyHandles[handle];
+	}
+	const T* getHandle(int handle) const
+	{
+		return &m_bodyHandles[handle];
+	}
+
+	void increaseHandleCapacity(int extraCapacity)
+	{
+		int curCapacity = m_bodyHandles.size();
+		btAssert(curCapacity == m_numUsedHandles);
+		int newCapacity = curCapacity + extraCapacity;
+		m_bodyHandles.resize(newCapacity);
+
+		{
+			for (int i = curCapacity; i < newCapacity; i++)
+				m_bodyHandles[i].SetNextFree(i + 1);
+
+
+			m_bodyHandles[newCapacity - 1].SetNextFree(-1);
+		}
+		m_firstFreeHandle = curCapacity;
+	}
+	void initHandles()
+	{
+		m_numUsedHandles = 0;
+		m_firstFreeHandle = -1;
+
+		increaseHandleCapacity(1);
+	}
+
+	void exitHandles()
+	{
+		m_bodyHandles.resize(0);
+		m_firstFreeHandle = -1;
+		m_numUsedHandles = 0;
+	}
+
+	int allocHandle()
+	{
+		btAssert(m_firstFreeHandle>=0);
+
+		int handle = m_firstFreeHandle;
+		m_firstFreeHandle = getHandle(handle)->GetNextFree();
+		m_numUsedHandles++;
+
+		if (m_firstFreeHandle<0)
+		{
+			//int curCapacity = m_bodyHandles.size();
+			int additionalCapacity= m_bodyHandles.size();
+			increaseHandleCapacity(additionalCapacity);
+
+
+			getHandle(handle)->SetNextFree(m_firstFreeHandle);
+		}
+
+
+		return handle;
+	}
+
+
+	void freeHandle(int handle)
+	{
+		btAssert(handle >= 0);
+
+		getHandle(handle)->SetNextFree(m_firstFreeHandle);
+		m_firstFreeHandle = handle;
+
+		m_numUsedHandles--;
+	}
+};
+	///end handle management
+	
+	#endif //B3_RESIZABLE_POOL_H
+