From 0de2f5c5872ebdc54b5935ef8def02972acdfa2c Mon Sep 17 00:00:00 2001 From: Christophe Riccio Date: Mon, 27 Oct 2014 19:07:23 +0100 Subject: [PATCH] Added powerOfTwo functions --- glm/gtx/bit.hpp | 58 +++++++++++++++++++++++++++ glm/gtx/bit.inl | 103 ++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 161 insertions(+) create mode 100644 glm/gtx/bit.inl diff --git a/glm/gtx/bit.hpp b/glm/gtx/bit.hpp index dbafced9..92138626 100644 --- a/glm/gtx/bit.hpp +++ b/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 + 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 class vecType> + GLM_FUNC_DECL vecType highestBitValue(vecType const & value); + + /// Return the power of two number which value is just higher the input value. + /// + /// @see gtx_bit + template + 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 class vecType> + GLM_FUNC_DECL vecType powerOfTwoAbove(vecType const & value); + + /// Return the power of two number which value is just lower the input value. + /// + /// @see gtx_bit + template + 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 class vecType> + GLM_FUNC_DECL vecType powerOfTwoBelow(vecType const & value); + + /// Return the power of two number which value is the closet to the input value. + /// + /// @see gtx_bit + template + 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 class vecType> + GLM_FUNC_DECL vecType powerOfTwoNearest(vecType const & value); + + /// @} +} //namespace glm + + +#include "bit.inl" + diff --git a/glm/gtx/bit.inl b/glm/gtx/bit.inl new file mode 100644 index 00000000..ccf87db1 --- /dev/null +++ b/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 + 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 class vecType> + GLM_FUNC_QUALIFIER vecType highestBitValue(vecType const & v) + { + return detail::functor1::call(highestBitValue, v); + } + + /////////////////// + // powerOfTwoAbove + + template + GLM_FUNC_QUALIFIER genType powerOfTwoAbove(genType value) + { + return isPowerOfTwo(value) ? value : highestBitValue(value) << 1; + } + + template class vecType> + GLM_FUNC_QUALIFIER vecType powerOfTwoAbove(vecType const & v) + { + return detail::functor1::call(powerOfTwoAbove, v); + } + + /////////////////// + // powerOfTwoBelow + + template + GLM_FUNC_QUALIFIER genType powerOfTwoBelow(genType value) + { + return isPowerOfTwo(value) ? value : highestBitValue(value); + } + + template class vecType> + GLM_FUNC_QUALIFIER vecType powerOfTwoBelow(vecType const & v) + { + return detail::functor1::call(powerOfTwoBelow, v); + } + + ///////////////////// + // powerOfTwoNearest + + template + 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 class vecType> + GLM_FUNC_QUALIFIER vecType powerOfTwoNearest(vecType const & v) + { + return detail::functor1::call(powerOfTwoNearest, v); + } + +}//namespace glm