Added powerOfTwo functions

glm/gtx/bit.hpp

@@ -45,3 +45,61 @@
 #if(defined(GLM_MESSAGES))
 #	pragma message("GLM: GLM_GTX_bit extension is deprecated, include GLM_GTC_bitfield and GLM_GTC_integer instead")
 #endif
+
+namespace glm
+{
+	/// @addtogroup gtx_bit
+	/// @{
+
+	/// @see gtx_bit
+	template <typename genIUType>
+	GLM_FUNC_DECL genIUType highestBitValue(genIUType Value);
+
+	/// Find the highest bit set to 1 in a integer variable and return its value.
+	///
+	/// @see gtx_bit
+	template <typename T, precision P, template <typename, precision> class vecType>
+	GLM_FUNC_DECL vecType<T, P> highestBitValue(vecType<T, P> const & value);
+
+	/// Return the power of two number which value is just higher the input value.
+	///
+	/// @see gtx_bit
+	template <typename genIUType>
+	GLM_FUNC_DECL genIUType powerOfTwoAbove(genIUType Value);
+
+	/// Return the power of two number which value is just higher the input value.
+	///
+	/// @see gtx_bit
+	template <typename T, precision P, template <typename, precision> class vecType>
+	GLM_FUNC_DECL vecType<T, P> powerOfTwoAbove(vecType<T, P> const & value);
+
+	/// Return the power of two number which value is just lower the input value.
+	///
+	/// @see gtx_bit
+	template <typename genIUType>
+	GLM_FUNC_DECL genIUType powerOfTwoBelow(genIUType Value);
+
+	/// Return the power of two number which value is just lower the input value.
+	///
+	/// @see gtx_bit
+	template <typename T, precision P, template <typename, precision> class vecType>
+	GLM_FUNC_DECL vecType<T, P> powerOfTwoBelow(vecType<T, P> const & value);
+
+	/// Return the power of two number which value is the closet to the input value.
+	///
+	/// @see gtx_bit
+	template <typename genIUType>
+	GLM_FUNC_DECL genIUType powerOfTwoNearest(genIUType Value);
+
+	/// Return the power of two number which value is the closet to the input value.
+	///
+	/// @see gtx_bit
+	template <typename T, precision P, template <typename, precision> class vecType>
+	GLM_FUNC_DECL vecType<T, P> powerOfTwoNearest(vecType<T, P> const & value);
+
+	/// @}
+} //namespace glm
+
+
+#include "bit.inl"
+

glm/gtx/bit.inl

@@ -0,0 +1,103 @@
+///////////////////////////////////////////////////////////////////////////////////
+/// OpenGL Mathematics (glm.g-truc.net)
+///
+/// Copyright (c) 2005 - 2014 G-Truc Creation (www.g-truc.net)
+/// Permission is hereby granted, free of charge, to any person obtaining a copy
+/// of this software and associated documentation files (the "Software"), to deal
+/// in the Software without restriction, including without limitation the rights
+/// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+/// copies of the Software, and to permit persons to whom the Software is
+/// furnished to do so, subject to the following conditions:
+/// 
+/// The above copyright notice and this permission notice shall be included in
+/// all copies or substantial portions of the Software.
+/// 
+/// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+/// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+/// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+/// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+/// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+/// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+/// THE SOFTWARE.
+///
+/// @ref gtx_bit
+/// @file glm/gtx/bit.inl
+/// @date 2014-11-25 / 2014-11-25
+/// @author Christophe Riccio
+///////////////////////////////////////////////////////////////////////////////////
+
+namespace glm
+{
+	///////////////////
+	// highestBitValue
+
+	template <typename genIUType>
+	GLM_FUNC_QUALIFIER genIUType highestBitValue(genIUType Value)
+	{
+		genIUType tmp = Value;
+		genIUType result = genIUType(0);
+		while(tmp)
+		{
+			result = (tmp & (~tmp + 1)); // grab lowest bit
+			tmp &= ~result; // clear lowest bit
+		}
+		return result;
+	}
+
+	template <typename T, precision P, template <typename, precision> class vecType>
+	GLM_FUNC_QUALIFIER vecType<T, P> highestBitValue(vecType<T, P> const & v)
+	{
+		return detail::functor1<T, T, P, vecType>::call(highestBitValue, v);
+	}
+
+	///////////////////
+	// powerOfTwoAbove
+
+	template <typename genType>
+	GLM_FUNC_QUALIFIER genType powerOfTwoAbove(genType value)
+	{
+		return isPowerOfTwo(value) ? value : highestBitValue(value) << 1;
+	}
+
+	template <typename T, precision P, template <typename, precision> class vecType>
+	GLM_FUNC_QUALIFIER vecType<T, P> powerOfTwoAbove(vecType<T, P> const & v)
+	{
+		return detail::functor1<T, T, P, vecType>::call(powerOfTwoAbove, v);
+	}
+
+	///////////////////
+	// powerOfTwoBelow
+
+	template <typename genType>
+	GLM_FUNC_QUALIFIER genType powerOfTwoBelow(genType value)
+	{
+		return isPowerOfTwo(value) ? value : highestBitValue(value);
+	}
+
+	template <typename T, precision P, template <typename, precision> class vecType>
+	GLM_FUNC_QUALIFIER vecType<T, P> powerOfTwoBelow(vecType<T, P> const & v)
+	{
+		return detail::functor1<T, T, P, vecType>::call(powerOfTwoBelow, v);
+	}
+
+	/////////////////////
+	// powerOfTwoNearest
+
+	template <typename genType>
+	GLM_FUNC_QUALIFIER genType powerOfTwoNearest(genType value)
+	{
+		if(isPowerOfTwo(value))
+			return value;
+
+		genType const prev = highestBitValue(value);
+		genType const next = prev << 1;
+		return (next - value) < (value - prev) ? next : prev;
+	}
+
+	template <typename T, precision P, template <typename, precision> class vecType>
+	GLM_FUNC_QUALIFIER vecType<T, P> powerOfTwoNearest(vecType<T, P> const & v)
+	{
+		return detail::functor1<T, T, P, vecType>::call(powerOfTwoNearest, v);
+	}
+
+}//namespace glm