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Diffstat (limited to 'include/basebmp/accessorfunctors.hxx')
-rw-r--r-- | include/basebmp/accessorfunctors.hxx | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/include/basebmp/accessorfunctors.hxx b/include/basebmp/accessorfunctors.hxx new file mode 100644 index 000000000000..58550b010512 --- /dev/null +++ b/include/basebmp/accessorfunctors.hxx @@ -0,0 +1,181 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ +/* + * This file is part of the LibreOffice project. + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * This file incorporates work covered by the following license notice: + * + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed + * with this work for additional information regarding copyright + * ownership. The ASF licenses this file to you under the Apache + * License, Version 2.0 (the "License"); you may not use this file + * except in compliance with the License. You may obtain a copy of + * the License at http://www.apache.org/licenses/LICENSE-2.0 . + */ + +#ifndef INCLUDED_BASEBMP_ACCESSORFUNCTORS_HXX +#define INCLUDED_BASEBMP_ACCESSORFUNCTORS_HXX + +#include <osl/diagnose.h> +#include <basebmp/metafunctions.hxx> + +#include <functional> + +namespace basebmp +{ + +// Some common accessor functors +// ------------------------------------------------------------ + + +/// combine two values via XOR +template< typename T > struct XorFunctor : public std::binary_function<T,T,T> +{ + T operator()( T v1, T v2 ) const { return v1 ^ v2; } +}; + +//----------------------------------------------------------------------------- + +/// Base class, passing on the arg types +template< typename T, typename M > struct MaskFunctorBase : + public TernaryFunctorBase<T,M,T,T> {}; + + +/** Let a mask flag decide between two values + + @tpl polarity + Mask polarity. When true, a false in the mask denotes + transparency, i.e. the original value will display. And vice + versa. + */ +template< typename T, + typename M, + bool polarity > struct GenericOutputMaskFunctor : public MaskFunctorBase<T,M> +{ + /// Ternary mask operation - selects v1 for !m == polarity, v2 otherwise + T operator()( T v1, M m, T v2 ) const + { + return !m == polarity ? v1 : v2; + } +}; + +/** Let a mask bit decide between two values (specialization for + integer mask types) + */ +template< typename T, + typename M, + bool polarity > struct IntegerOutputMaskFunctor; +template< typename T, + typename M > struct IntegerOutputMaskFunctor<T,M,true> : public MaskFunctorBase<T,M> +{ + /** Mask v with state of m + + @return v2, if m != 0, v1 otherwise. + */ + T operator()( T v1, M m, T v2 ) const + { + typedef typename make_unsigned<T>::type unsigned_T; + + // mask will be 0, iff m == 0, and 1 otherwise + const T mask( unsigned_cast<T>(m | -m) >> (sizeof(unsigned_T)*8 - 1) ); + return v1*(M)(1-mask) + v2*mask; + } +}; +template< typename T, + typename M > struct IntegerOutputMaskFunctor<T,M,false> : public MaskFunctorBase<T,M> +{ + /** Mask v with state of m + + @return v2, if m != 0, v1 otherwise. + */ + T operator()( T v1, M m, T v2 ) const + { + typedef typename make_unsigned<T>::type unsigned_T; + + // mask will be 0, iff m == 0, and 1 otherwise + const T mask( unsigned_cast<T>(m | -m) >> (sizeof(unsigned_T)*8 - 1) ); + return v1*mask + v2*(M)(1-mask); + } +}; + +/** Let a mask bit decide between two values (specialization for + binary-valued mask types) + */ +template< typename T, typename M, bool polarity > struct FastIntegerOutputMaskFunctor; +template< typename T, typename M > struct FastIntegerOutputMaskFunctor<T,M,true> : + public MaskFunctorBase<T,M> +{ + /// Specialization, only valid if mask can only attain 0 or 1 + T operator()( T v1, M m, T v2 ) const + { + OSL_ASSERT(m<=1); + + return v1*(M)(1-m) + v2*m; + } +}; +template< typename T, typename M > struct FastIntegerOutputMaskFunctor<T,M,false> : + public MaskFunctorBase<T,M> +{ + /// Specialization, only valid if mask can only attain 0 or 1 + T operator()( T v1, M m, T v2 ) const + { + OSL_ASSERT(m<=1); + + return v1*m + v2*(M)(1-m); + } +}; + +//----------------------------------------------------------------------------- + +/** Split a pair value from a JoinImageAccessorAdapter into its + individual values, and pass it on to a ternary functor + + This wrapper is an adaptable binary functor, and can thus be used + with a BinarySetterFunctionAccessorAdapter. Useful e.g. for + out-of-image alpha channel, or a masked image. + + @tpl Functor + An adaptable ternary functor (as can e.g. be passed to the + TernarySetterFunctionAccessorAdapter) + */ +template< typename Functor > struct BinaryFunctorSplittingWrapper : + public std::binary_function<typename Functor::first_argument_type, + std::pair<typename Functor::third_argument_type, + typename Functor::second_argument_type>, + typename Functor::result_type> +{ +#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS +// making all members public, if no member template friends +private: + template<class A> friend struct BinaryFunctorSplittingWrapper; +#endif + Functor maFunctor; + +public: + BinaryFunctorSplittingWrapper() : maFunctor() {} + + template< class A > explicit + BinaryFunctorSplittingWrapper( + BinaryFunctorSplittingWrapper<A> const& src ) : maFunctor(src.maFunctor) {} + + template< class F > explicit + BinaryFunctorSplittingWrapper( F const& func ) : maFunctor(func) {} + + typename Functor::result_type operator()( + typename Functor::first_argument_type v1, + std::pair< typename Functor::third_argument_type, + typename Functor::second_argument_type > const& v2 ) const + { + return maFunctor( v1, v2.second, v2.first ); + } +}; + +} // namespace basebmp + +#endif /* INCLUDED_BASEBMP_ACCESSORFUNCTORS_HXX */ + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |