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Diffstat (limited to 'include/basebmp/paletteimageaccessor.hxx')
-rw-r--r-- | include/basebmp/paletteimageaccessor.hxx | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/include/basebmp/paletteimageaccessor.hxx b/include/basebmp/paletteimageaccessor.hxx new file mode 100644 index 000000000000..6f0164e64af6 --- /dev/null +++ b/include/basebmp/paletteimageaccessor.hxx @@ -0,0 +1,162 @@ +/* -*- 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_PALETTEIMAGEACCESSOR_HXX +#define INCLUDED_BASEBMP_PALETTEIMAGEACCESSOR_HXX + +#include <basebmp/colortraits.hxx> +#include <basebmp/accessortraits.hxx> + +#include <vigra/numerictraits.hxx> +#include <vigra/metaprogramming.hxx> + +#include <algorithm> +#include <functional> + +namespace basebmp +{ + +/** Access pixel data via palette indirection + + @tpl Accessor + Raw accessor, to be used to actually access the pixel values + + @tpl ColorType + The color value type to use - e.g. the palette is an array of that + type + */ +template< class Accessor, typename ColorType > class PaletteImageAccessor +{ +public: + typedef typename Accessor::value_type data_type; + typedef ColorType value_type; + +#ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS +// making all members public, if no member template friends +private: + template<class A, typename C> friend class PaletteImageAccessor; +#endif + + Accessor maAccessor; + const value_type* mpPalette; + std::size_t mnNumEntries; + +public: + PaletteImageAccessor() : + maAccessor(), + mpPalette(0), + mnNumEntries(0) + {} + + template< class A > explicit + PaletteImageAccessor( PaletteImageAccessor<A,ColorType> const& rSrc ) : + maAccessor( rSrc.maAccessor ), + mpPalette( rSrc.mpPalette ), + mnNumEntries( rSrc.mnNumEntries ) + {} + + PaletteImageAccessor( const value_type* pPalette, + std::size_t numEntries ) : + maAccessor(), + mpPalette(pPalette), + mnNumEntries(numEntries) + {} + + template< class T > PaletteImageAccessor( T accessor, + const value_type* pPalette, + std::size_t numEntries ) : + maAccessor(accessor), + mpPalette(pPalette), + mnNumEntries(numEntries) + {} + + // ------------------------------------------------------- + + Accessor const& getWrappedAccessor() const { return maAccessor; } + Accessor& getWrappedAccessor() { return maAccessor; } + + // ------------------------------------------------------- + + data_type lookup(value_type const& v) const + { + // TODO(P3): use table-based/octree approach here! + const value_type* best_entry; + const value_type* palette_end( mpPalette+mnNumEntries ); + if( (best_entry=std::find( mpPalette, palette_end, v)) != palette_end ) + return best_entry-mpPalette; + + const value_type* curr_entry( mpPalette ); + best_entry = curr_entry; + while( curr_entry != palette_end ) + { + if( ColorTraits<value_type>::distance(*curr_entry, + *best_entry) + > ColorTraits<value_type>::distance(*curr_entry, + v) ) + { + best_entry = curr_entry; + } + + ++curr_entry; + } + + return best_entry-mpPalette; + } + + // ------------------------------------------------------- + + template< class Iterator > + value_type operator()(Iterator const& i) const + { + return mpPalette[ maAccessor(i) ]; + } + + template< class Iterator, class Difference > + value_type operator()(Iterator const& i, Difference const& diff) const + { + return mpPalette[ maAccessor(i,diff) ]; + } + + // ------------------------------------------------------- + + template< typename V, class Iterator > + void set(V const& value, Iterator const& i) const + { + maAccessor.set( + lookup( + vigra::detail::RequiresExplicitCast<value_type>::cast(value) ), + i ); + } + + template< typename V, class Iterator, class Difference > + void set(V const& value, Iterator const& i, Difference const& diff) const + { + maAccessor.set( + lookup( + vigra::detail::RequiresExplicitCast<value_type>::cast(value) ), + i, + diff ); + } +}; + +} // namespace basebmp + +#endif /* INCLUDED_BASEBMP_PALETTEIMAGEACCESSOR_HXX */ + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ |