| /************************************************************** |
| * |
| * 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 */ |