Line data    Source code

       1             : /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
       2             : /*
       3             :  * This file is part of the LibreOffice project.
       4             :  *
       5             :  * This Source Code Form is subject to the terms of the Mozilla Public
       6             :  * License, v. 2.0. If a copy of the MPL was not distributed with this
       7             :  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
       8             :  *
       9             :  * This file incorporates work covered by the following license notice:
      10             :  *
      11             :  *   Licensed to the Apache Software Foundation (ASF) under one or more
      12             :  *   contributor license agreements. See the NOTICE file distributed
      13             :  *   with this work for additional information regarding copyright
      14             :  *   ownership. The ASF licenses this file to you under the Apache
      15             :  *   License, Version 2.0 (the "License"); you may not use this file
      16             :  *   except in compliance with the License. You may obtain a copy of
      17             :  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
      18             :  */
      19             : 
      20             : #ifndef INCLUDED_BASEBMP_PALETTEIMAGEACCESSOR_HXX
      21             : #define INCLUDED_BASEBMP_PALETTEIMAGEACCESSOR_HXX
      22             : 
      23             : #include <basebmp/colortraits.hxx>
      24             : #include <basebmp/accessortraits.hxx>
      25             : 
      26             : #include <vigra/numerictraits.hxx>
      27             : #include <vigra/metaprogramming.hxx>
      28             : 
      29             : #include <algorithm>
      30             : #include <functional>
      31             : 
      32             : namespace basebmp
      33             : {
      34             : 
      35             : /** Access pixel data via palette indirection
      36             : 
      37             :     @tpl Accessor
      38             :     Raw accessor, to be used to actually access the pixel values
      39             : 
      40             :     @tpl ColorType
      41             :     The color value type to use - e.g. the palette is an array of that
      42             :     type
      43             :  */
      44             : template< class Accessor, typename ColorType > class PaletteImageAccessor
      45             : {
      46             : public:
      47             :     typedef typename Accessor::value_type  data_type;
      48             :     typedef ColorType                      value_type;
      49             : 
      50             : #ifndef BOOST_NO_MEMBER_TEMPLATE_FRIENDS
      51             : // making all members public, if no member template friends
      52             : private:
      53             :     template<class A, typename C> friend class PaletteImageAccessor;
      54             : #endif
      55             : 
      56             :     Accessor          maAccessor;
      57             :     const value_type* mpPalette;
      58             :     std::size_t       mnNumEntries;
      59             : 
      60             : public:
      61             :     PaletteImageAccessor() :
      62             :         maAccessor(),
      63             :         mpPalette(0),
      64             :         mnNumEntries(0)
      65             :     {}
      66             : 
      67             :     template< class A > explicit
      68           0 :     PaletteImageAccessor( PaletteImageAccessor<A,ColorType> const& rSrc ) :
      69             :         maAccessor( rSrc.maAccessor ),
      70             :         mpPalette( rSrc.mpPalette ),
      71           0 :         mnNumEntries( rSrc.mnNumEntries )
      72           0 :     {}
      73             : 
      74           0 :     PaletteImageAccessor( const value_type* pPalette,
      75             :                           std::size_t       numEntries ) :
      76             :         maAccessor(),
      77             :         mpPalette(pPalette),
      78           0 :         mnNumEntries(numEntries)
      79           0 :     {}
      80             : 
      81             :     template< class T > PaletteImageAccessor( T                 accessor,
      82             :                                               const value_type* pPalette,
      83             :                                               std::size_t       numEntries ) :
      84             :         maAccessor(accessor),
      85             :         mpPalette(pPalette),
      86             :         mnNumEntries(numEntries)
      87             :     {}
      88             : 
      89             : 
      90             : 
      91             :     Accessor const& getWrappedAccessor() const { return maAccessor; }
      92             :     Accessor&       getWrappedAccessor() { return maAccessor; }
      93             : 
      94             : 
      95             : 
      96           0 :     data_type lookup(value_type const& v) const
      97             :     {
      98             :         // TODO(P3): use table-based/octree approach here!
      99             :         const value_type* best_entry;
     100           0 :         const value_type* palette_end( mpPalette+mnNumEntries );
     101           0 :         if( (best_entry=std::find( mpPalette, palette_end, v)) != palette_end )
     102           0 :             return best_entry-mpPalette;
     103             : 
     104           0 :         const value_type* curr_entry( mpPalette );
     105           0 :         best_entry = curr_entry;
     106           0 :         while( curr_entry != palette_end )
     107             :         {
     108           0 :             if( ColorTraits<value_type>::distance(*curr_entry,
     109           0 :                                                   *best_entry)
     110             :                 > ColorTraits<value_type>::distance(*curr_entry,
     111           0 :                                                     v) )
     112             :             {
     113           0 :                 best_entry = curr_entry;
     114             :             }
     115             : 
     116           0 :             ++curr_entry;
     117             :         }
     118             : 
     119           0 :         return best_entry-mpPalette;
     120             :     }
     121             : 
     122             : 
     123             : 
     124             :     template< class Iterator >
     125           0 :     value_type operator()(Iterator const& i) const
     126             :     {
     127           0 :         return mpPalette[ maAccessor(i) ];
     128             :     }
     129             : 
     130             :     template< class Iterator, class Difference >
     131             :     value_type operator()(Iterator const& i, Difference const& diff) const
     132             :     {
     133             :         return mpPalette[ maAccessor(i,diff) ];
     134             :     }
     135             : 
     136             : 
     137             : 
     138             :     template< typename V, class Iterator >
     139           0 :     void set(V const& value, Iterator const& i) const
     140             :     {
     141           0 :         maAccessor.set(
     142             :             lookup(
     143           0 :                 vigra::detail::RequiresExplicitCast<value_type>::cast(value) ),
     144             :             i );
     145           0 :     }
     146             : 
     147             :     template< typename V, class Iterator, class Difference >
     148             :     void set(V const& value, Iterator const& i, Difference const& diff) const
     149             :     {
     150             :         maAccessor.set(
     151             :             lookup(
     152             :                 vigra::detail::RequiresExplicitCast<value_type>::cast(value) ),
     153             :             i,
     154             :             diff );
     155             :     }
     156             : };
     157             : 
     158             : } // namespace basebmp
     159             : 
     160             : #endif /* INCLUDED_BASEBMP_PALETTEIMAGEACCESSOR_HXX */
     161             : 
     162             : /* vim:set shiftwidth=4 softtabstop=4 expandtab: */