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/* -*- 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_PALETTEIMAGEACCESSOR_HXX
#define INCLUDED_BASEBMP_INC_PALETTEIMAGEACCESSOR_HXX
#include <colortraits.hxx>
#include <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_INC_PALETTEIMAGEACCESSOR_HXX */
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
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