Initial commit

engine/core/bitVectorW.h

@@ -0,0 +1,91 @@
+//-----------------------------------------------------------------------------
+// Torque Game Engine
+// Copyright (C) GarageGames.com, Inc.
+//-----------------------------------------------------------------------------
+
+#ifndef _BITVECTORW_H_
+#define _BITVECTORW_H_
+
+#ifndef _PLATFORM_H_
+#include "platform/platform.h"
+#endif
+
+/// @see BitVector
+class BitVectorW
+{
+      U32   mNumEntries;
+      U32   mBitWidth;
+      U32   mBitMask;
+      U8 *  mDataPtr;
+
+   public:
+      BitVectorW()   {mDataPtr=NULL; setDims(0,0);}
+      ~BitVectorW()  {if(mDataPtr) delete [] mDataPtr;}
+
+      U32   bitWidth() const     {return mBitWidth;}
+      U32   numEntries() const   {return mNumEntries;}
+      U8 *  dataPtr() const      {return mDataPtr;}
+
+      U32   getU17(U32 idx) const;        // get and set for bit widths
+      void  setU17(U32 idx, U32 val);     // of 17 or less
+      U32   numBytes() const;
+      void  setDims(U32 sz, U32 w);
+};
+
+//-------------------------------------------------------------------------------------
+
+inline U32 BitVectorW::numBytes() const
+{
+   if (mNumEntries > 0)
+      return (mBitWidth * mNumEntries) + 32 >> 3;
+   else
+      return 0;
+}
+
+// Alloc the data - note it does work for a bit width of zero (lookups return zero)
+inline void BitVectorW::setDims(U32 size, U32 width)
+{
+   if (mDataPtr)
+      delete [] mDataPtr;
+
+   if (size > 0 && width <= 17)
+   {
+      mBitWidth = width;
+      mNumEntries = size;
+      mBitMask = (1 << width) - 1;
+      U32 dataSize = numBytes();
+      mDataPtr = new U8 [dataSize];
+      dMemset(mDataPtr, 0, dataSize);
+   }
+   else
+   {
+      mDataPtr = NULL;
+      mBitWidth = mBitMask = mNumEntries = 0;
+   }
+}
+
+//-------------------------------------------------------------------------------------
+// For coding ease, the get and set methods might read or write an extra byte or two.
+// If more or less max bit width is ever needed, add or remove the x[] expressions.
+
+inline U32 BitVectorW::getU17(U32 i) const
+{
+   if (mDataPtr) {
+      register U8 *  x = &mDataPtr[(i *= mBitWidth) >> 3];
+      return (U32(*x) + (U32(x[1])<<8) + (U32(x[2])<<16) >> (i&7)) & mBitMask;
+   }
+   return 0;
+}
+
+inline void BitVectorW::setU17(U32 i, U32 value)
+{
+   if (mDataPtr) {
+      register U8 *  x = &mDataPtr[(i *= mBitWidth) >> 3];
+      register U32   mask = mBitMask << (i &= 7);
+      x[0] = (x[0] & (~mask >>  0))  |  ((value <<= i) & (mask >>  0));
+      x[1] = (x[1] & (~mask >>  8))  |  ((value >>  8) & (mask >>  8));
+      x[2] = (x[2] & (~mask >> 16))  |  ((value >> 16) & (mask >> 16));
+   }
+}
+
+#endif //_BITVECTORW_H_