boost/gil/extension/io/jpeg/detail/supported_types.hpp

   1 //
   2 // Copyright 2007-2008 Christian Henning, Andreas Pokorny, Lubomir Bourdev
   3 //
   4 // Distributed under the Boost Software License, Version 1.0
   5 // See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt
   7 //
   8 #ifndef BOOST_GIL_EXTENSION_IO_JPEG_DETAIL_SUPPORTED_TYPES_HPP
   9 #define BOOST_GIL_EXTENSION_IO_JPEG_DETAIL_SUPPORTED_TYPES_HPP
  10
  11 #include <boost/gil/extension/io/jpeg/tags.hpp>
  12
  13 #include <boost/gil/channel.hpp>
  14 #include <boost/gil/color_base.hpp>
  15
  16 #include <type_traits>
  17
  18 namespace boost { namespace gil { namespace detail {
  19
  20 // Read support
  21
  22 template< jpeg_color_space::type ColorSpace >
  23 struct jpeg_rw_support_base
  24 {
  25     static const jpeg_color_space::type _color_space = ColorSpace;
  26 };
  27
  28 template< typename Channel
  29         , typename ColorSpace
  30         >
  31 struct jpeg_read_support : read_support_false
  32                          , jpeg_rw_support_base< JCS_UNKNOWN > {};
  33
  34 template<>
  35 struct jpeg_read_support<uint8_t
  36                         , rgb_t
  37                         > : read_support_true
  38                           , jpeg_rw_support_base< JCS_RGB > {};
  39
  40 template<>
  41 struct jpeg_read_support<uint8_t
  42                         , cmyk_t
  43                         > : read_support_true
  44                           , jpeg_rw_support_base< JCS_CMYK > {};
  45
  46 template<>
  47 struct jpeg_read_support<uint8_t
  48                         , gray_t
  49                         > : read_support_true
  50                           , jpeg_rw_support_base< JCS_GRAYSCALE > {};
  51
  52 // Write support
  53
  54 template< typename Channel
  55         , typename ColorSpace
  56         >
  57 struct jpeg_write_support : write_support_false
  58                           , jpeg_rw_support_base< JCS_UNKNOWN > {};
  59
  60 template<>
  61 struct jpeg_write_support<uint8_t
  62                          , gray_t
  63                          > : write_support_true
  64                           , jpeg_rw_support_base< JCS_GRAYSCALE > {};
  65
  66 template<>
  67 struct jpeg_write_support<uint8_t
  68                          , rgb_t
  69                          > : write_support_true
  70                           , jpeg_rw_support_base< JCS_RGB > {};
  71
  72 template<>
  73 struct jpeg_write_support<uint8_t
  74                          , cmyk_t
  75                          > : write_support_true
  76                           , jpeg_rw_support_base< JCS_CMYK > {};
  77
  78 } // namespace detail
  79
  80 template<typename Pixel>
  81 struct is_read_supported<Pixel, jpeg_tag>
  82     : std::integral_constant
  83     <
  84         bool,
  85         detail::jpeg_read_support
  86         <
  87             typename channel_type<Pixel>::type,
  88             typename color_space_type<Pixel>::type
  89         >::is_supported
  90     >
  91 {
  92     using parent_t = detail::jpeg_read_support
  93         <
  94             typename channel_type<Pixel>::type,
  95             typename color_space_type<Pixel>::type
  96         >;
  97
  98     static const typename jpeg_color_space::type _color_space = parent_t::_color_space;
  99 };
 100
 101 template<typename Pixel>
 102 struct is_write_supported<Pixel, jpeg_tag>
 103     : std::integral_constant
 104     <
 105         bool,
 106         detail::jpeg_write_support
 107         <
 108             typename channel_type<Pixel>::type,
 109             typename color_space_type<Pixel>::type
 110         >::is_supported
 111     >
 112 {};
 113
 114 } // namespace gil
 115 } // namespace boost
 116
 117 #endif