basebmp/source/intconversion.hxx

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  30
  31 #ifndef INCLUDED_BASEBMP_INTCONVERSION_HXX
  32 #define INCLUDED_BASEBMP_INTCONVERSION_HXX
  33
  34 #include <vigra/rgbvalue.hxx>
  35 #include <functional>
  36
  37 namespace basebmp
  38 {
  39     // metafunctions to retrieve correct POD from/to basebmp::Color
  40     //------------------------------------------------------------------------
  41
  42     /// type-safe conversion from RgbValue to packed int32
  43     template< class RgbVal > struct UInt32FromRgbValue
  44     {
  45         sal_uInt32 operator()( RgbVal const& c ) const
  46         {
  47             return (c[0] << 16) | (c[1] << 8) | c[2];
  48         }
  49     };
  50
  51     /// type-safe conversion from packed int32 to RgbValue
  52     template< class RgbVal > struct RgbValueFromUInt32
  53     {
  54         RgbVal operator()( sal_uInt32 c ) const
  55         {
  56             return RgbVal((c >> 16) & 0xFF,
  57                           (c >> 8) & 0xFF,
  58                           c & 0xFF);
  59         }
  60     };
  61
  62     /// Get converter from given data type to sal_uInt32
  63     template< typename DataType > struct uInt32Converter
  64     {
  65         typedef std::identity<DataType> to;
  66         typedef std::identity<DataType> from;
  67     };
  68     template< unsigned int RedIndex,
  69               unsigned int GreenIndex,
  70               unsigned int BlueIndex > struct uInt32Converter<
  71                   vigra::RGBValue< sal_uInt8,
  72                                    RedIndex,
  73                                    GreenIndex,
  74                                    BlueIndex > >
  75     {
  76         typedef UInt32FromRgbValue<
  77             vigra::RGBValue< sal_uInt8,
  78                              RedIndex,
  79                              GreenIndex,
  80                              BlueIndex > >
  81             to;
  82         typedef RgbValueFromUInt32<
  83             vigra::RGBValue< sal_uInt8,
  84                              RedIndex,
  85                              GreenIndex,
  86                              BlueIndex > >
  87             from;
  88     };
  89 }
  90
  91 #endif /* INCLUDED_BASEBMP_INTCONVERSION_HXX */