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Diffstat (limited to 'basebmp/inc/stridedarrayiterator.hxx')
-rw-r--r-- | basebmp/inc/stridedarrayiterator.hxx | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/basebmp/inc/stridedarrayiterator.hxx b/basebmp/inc/stridedarrayiterator.hxx new file mode 100644 index 000000000000..821d3aa08414 --- /dev/null +++ b/basebmp/inc/stridedarrayiterator.hxx @@ -0,0 +1,108 @@ +/* -*- 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_INC_STRIDEDARRAYITERATOR_HXX +#define INCLUDED_BASEBMP_INC_STRIDEDARRAYITERATOR_HXX + +#include <metafunctions.hxx> + +namespace basebmp +{ + +/** Like vigra::StridedArrayIterator + + Changed semantics re. DirectionSelector<StridedArrayTag>: stride + now counts in <em>raw</em> bytes + + Adapts given ptr, in a way that iterator increments move forward + in strided steps. Stride can, by the way, also be negative + */ +template< typename T > class StridedArrayIterator +{ +public: + typedef typename clone_const<T, unsigned char>::type internal_type; + + /** Create iterator + + @param stride + + Stride in bytes. Given value should better match memory layout + of T, as memory gets reinterpret-casted. + */ + explicit StridedArrayIterator(int stride, T* ptr = 0) : + stride_(stride), + current_(reinterpret_cast<internal_type*>(ptr)) + {} + + /** Copy from other StridedArrayIterator, plus given offset + + @param offset + Offset in bytes + */ + StridedArrayIterator( StridedArrayIterator const& rSrc, + int offset ) : + stride_(rSrc.stride_), + current_(reinterpret_cast<internal_type*>( + reinterpret_cast<T*>(rSrc.current_)+offset)) + {} + + void operator++() {current_ += stride_; } + void operator++(int) {current_ += stride_; } + void operator--() {current_ -= stride_; } + void operator--(int) {current_ -= stride_; } + void operator+=(int dy) {current_ += dy*stride_; } + void operator-=(int dy) {current_ -= dy*stride_; } + + int operator-(StridedArrayIterator const & rhs) const + { return (current_ - rhs.current_) / stride_; } + + bool operator==(StridedArrayIterator const & rhs) const + { return current_ == rhs.current_; } + + bool operator!=(StridedArrayIterator const & rhs) const + { return current_ != rhs.current_; } + + bool operator<(StridedArrayIterator const & rhs) const + { return *this - rhs < 0; } + + bool operator<=(StridedArrayIterator const & rhs) const + { return *this - rhs <= 0; } + + bool operator>(StridedArrayIterator const & rhs) const + { return *this - rhs > 0; } + + bool operator>=(StridedArrayIterator const & rhs) const + { return *this - rhs >= 0; } + + T* operator()() const + { return reinterpret_cast<T*>(current_); } + + T* operator()(int d) const + { return reinterpret_cast<T*>(current_ + d*stride_); } + +private: + int stride_; + internal_type* current_; +}; + +} // namespace basebmp + +#endif /* INCLUDED_BASEBMP_INC_STRIDEDARRAYITERATOR_HXX */ + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |