/************************************************************** * * 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 * * Unless required by applicable law or agreed to in writing, * software distributed under the License is distributed on an * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY * KIND, either express or implied. See the License for the * specific language governing permissions and limitations * under the License. * *************************************************************/ #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 */