Initial commit

engine/core/idGenerator.h

@@ -0,0 +1,76 @@
+//-----------------------------------------------------------------------------
+// Torque Game Engine
+// Copyright (C) GarageGames.com, Inc.
+//-----------------------------------------------------------------------------
+
+#ifndef _IDGENERATOR_H_
+#define _IDGENERATOR_H_
+
+#ifndef _PLATFORM_H_
+#include "platform/platform.h"
+#endif
+#ifndef _TVECTOR_H_
+#include "core/tVector.h"
+#endif
+
+class IdGenerator
+{
+private:
+   U32 mIdBlockBase;
+   U32 mIdRangeSize;
+   Vector<U32> mPool;
+   U32 mNextId;
+
+   void reclaim();
+
+public:
+   IdGenerator(U32 base, U32 numIds)
+   {
+      VECTOR_SET_ASSOCIATION(mPool);
+
+      mIdBlockBase = base;
+      mIdRangeSize = numIds;
+      mNextId = mIdBlockBase;
+   }
+
+   void reset()
+   {
+      mPool.clear();
+      mNextId = mIdBlockBase;
+   }
+
+   U32 alloc()
+   {
+      // fist check the pool:
+      if(!mPool.empty())
+      {
+         U32 id = mPool.last();
+         mPool.pop_back();
+         reclaim();
+         return id;
+      }
+      if(mIdRangeSize && mNextId >= mIdBlockBase + mIdRangeSize)
+         return 0;
+
+      return mNextId++;
+   }
+
+   void free(U32 id)
+   {
+      AssertFatal(id >= mIdBlockBase, "IdGenerator::alloc: invalid id, id does not belong to this IdGenerator.")
+      if(id == mNextId - 1)
+      {
+         mNextId--;
+         reclaim();
+      }
+      else
+         mPool.push_back(id);
+   }
+
+   U32 numIdsUsed()
+   {
+      return mNextId - mIdBlockBase - mPool.size();
+   }
+};
+
+#endif