/**************************************************************
 * 
 * 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_INTCONVERSION_HXX
#define INCLUDED_BASEBMP_INTCONVERSION_HXX

#include <vigra/rgbvalue.hxx>
#include <functional>

namespace basebmp
{
    // metafunctions to retrieve correct POD from/to basebmp::Color
    //------------------------------------------------------------------------

    /// type-safe conversion from RgbValue to packed int32
    template< class RgbVal > struct UInt32FromRgbValue
    {
        sal_uInt32 operator()( RgbVal const& c ) const
        { 
            return (c[0] << 16) | (c[1] << 8) | c[2];
        }
    };

    /// type-safe conversion from packed int32 to RgbValue
    template< class RgbVal > struct RgbValueFromUInt32
    {
        RgbVal operator()( sal_uInt32 c ) const
        { 
            return RgbVal((c >> 16) & 0xFF,
                          (c >> 8) & 0xFF,
                          c & 0xFF);
        }
    };

    /// Get converter from given data type to sal_uInt32
    template< typename DataType > struct uInt32Converter
    {
        typedef std::identity<DataType> to;
        typedef std::identity<DataType> from;
    };
    template< unsigned int RedIndex, 
              unsigned int GreenIndex, 
              unsigned int BlueIndex > struct uInt32Converter< 
                  vigra::RGBValue< sal_uInt8,
                                   RedIndex,
                                   GreenIndex,
                                   BlueIndex > >
    {
        typedef UInt32FromRgbValue<
            vigra::RGBValue< sal_uInt8,
                             RedIndex,
                             GreenIndex,
                             BlueIndex > >
            to;
        typedef RgbValueFromUInt32<
            vigra::RGBValue< sal_uInt8,
                             RedIndex,
                             GreenIndex,
                             BlueIndex > >
            from;
    };
}

#endif /* INCLUDED_BASEBMP_INTCONVERSION_HXX */