2 // Copyright 2005-2007 Adobe Systems Incorporated
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
8 #ifndef BOOST_GIL_PACKED_PIXEL_HPP
9 #define BOOST_GIL_PACKED_PIXEL_HPP
11 #include <boost/gil/pixel.hpp>
12 #include <boost/gil/detail/mp11.hpp>
15 #include <type_traits>
17 namespace boost { namespace gil {
19 /// A model of a heterogeneous pixel whose channels are bit ranges.
20 /// For example 16-bit RGB in '565' format.
22 /// \defgroup ColorBaseModelPackedPixel packed_pixel
23 /// \ingroup ColorBaseModel
24 /// \brief A heterogeneous color base whose elements are reference proxies to channels in a pixel. Models ColorBaseValueConcept. This class is used to model packed pixels, such as 16-bit packed RGB.
26 /// \defgroup PixelModelPackedPixel packed_pixel
27 /// \ingroup PixelModel
28 /// \brief A heterogeneous pixel used to represent packed pixels with non-byte-aligned channels. Models PixelValueConcept
32 /// using rgb565_pixel_t = packed_pixel_type<uint16_t, mp11::mp_list-c<unsigned,5,6,5>, rgb_layout_t>::type;
33 /// static_assert(sizeof(rgb565_pixel_t) == 2, "");
35 /// rgb565_pixel_t r565;
36 /// get_color(r565,red_t()) = 31;
37 /// get_color(r565,green_t()) = 63;
38 /// get_color(r565,blue_t()) = 31;
39 /// assert(r565 == rgb565_pixel_t((uint16_t)0xFFFF));
42 /// \ingroup ColorBaseModelPackedPixel PixelModelPackedPixel PixelBasedModel
43 /// \brief Heterogeneous pixel value whose channel references can be constructed from the pixel bitfield and their index. Models ColorBaseValueConcept, PixelValueConcept, PixelBasedConcept
44 /// Typical use for this is a model of a packed pixel (like 565 RGB)
45 /// \tparam BitField Type that holds the bits of the pixel. Typically an integral type, like std::uint16_t.
46 /// \tparam ChannelRefs MP11 list whose elements are packed channels. They must be constructible from BitField. GIL uses packed_channel_reference
47 /// \tparam Layout defining the color space and ordering of the channels. Example value: rgb_layout_t
48 template <typename BitField, typename ChannelRefs, typename Layout>
51 BitField _bitfield{0}; // TODO: Make private
53 using layout_t = Layout;
54 using value_type = packed_pixel<BitField, ChannelRefs, Layout>;
55 using reference = value_type&;
56 using const_reference = value_type const&;
58 static constexpr bool is_mutable =
59 channel_traits<mp11::mp_front<ChannelRefs>>::is_mutable;
61 packed_pixel() = default;
62 explicit packed_pixel(const BitField& bitfield) : _bitfield(bitfield) {}
64 // Construct from another compatible pixel type
65 packed_pixel(const packed_pixel& p) : _bitfield(p._bitfield) {}
67 template <typename Pixel>
68 packed_pixel(Pixel const& p,
69 typename std::enable_if<is_pixel<Pixel>::value>::type* /*dummy*/ = nullptr)
71 check_compatible<Pixel>();
72 static_copy(p, *this);
75 packed_pixel(int chan0, int chan1)
78 static_assert(num_channels<packed_pixel>::value == 2, "");
79 gil::at_c<0>(*this) = chan0; gil::at_c<1>(*this) = chan1;
82 packed_pixel(int chan0, int chan1, int chan2)
85 static_assert(num_channels<packed_pixel>::value == 3, "");
86 gil::at_c<0>(*this) = chan0;
87 gil::at_c<1>(*this) = chan1;
88 gil::at_c<2>(*this) = chan2;
91 packed_pixel(int chan0, int chan1, int chan2, int chan3)
94 static_assert(num_channels<packed_pixel>::value == 4, "");
95 gil::at_c<0>(*this) = chan0;
96 gil::at_c<1>(*this) = chan1;
97 gil::at_c<2>(*this) = chan2;
98 gil::at_c<3>(*this) = chan3;
101 packed_pixel(int chan0, int chan1, int chan2, int chan3, int chan4)
104 static_assert(num_channels<packed_pixel>::value == 5, "");
105 gil::at_c<0>(*this) = chan0;
106 gil::at_c<1>(*this) = chan1;
107 gil::at_c<2>(*this) = chan2;
108 gil::at_c<3>(*this) = chan3;
109 gil::at_c<4>(*this) = chan4;
112 auto operator=(packed_pixel const& p) -> packed_pixel&
114 _bitfield = p._bitfield;
118 template <typename Pixel>
119 auto operator=(Pixel const& p) -> packed_pixel&
121 assign(p, is_pixel<Pixel>());
125 template <typename Pixel>
126 bool operator==(Pixel const& p) const
128 return equal(p, is_pixel<Pixel>());
131 template <typename Pixel>
132 bool operator!=(Pixel const& p) const { return !(*this==p); }
135 template <typename Pixel>
136 static void check_compatible()
138 gil_function_requires<PixelsCompatibleConcept<Pixel, packed_pixel>>();
141 template <typename Pixel>
142 void assign(Pixel const& p, std::true_type)
144 check_compatible<Pixel>();
145 static_copy(p, *this);
148 template <typename Pixel>
149 bool equal(Pixel const& p, std::true_type) const
151 check_compatible<Pixel>();
152 return static_equal(*this, p);
155 // Support for assignment/equality comparison of a channel with a grayscale pixel
156 static void check_gray()
158 static_assert(std::is_same<typename Layout::color_space_t, gray_t>::value, "");
161 template <typename Channel>
162 void assign(Channel const& channel, std::false_type)
165 gil::at_c<0>(*this) = channel;
168 template <typename Channel>
169 bool equal (Channel const& channel, std::false_type) const
172 return gil::at_c<0>(*this) == channel;
176 auto operator=(int channel) -> packed_pixel&
179 gil::at_c<0>(*this) = channel;
183 bool operator==(int channel) const
186 return gil::at_c<0>(*this) == channel;
190 /////////////////////////////
192 /////////////////////////////
194 template <typename BitField, typename ChannelRefs, typename Layout, int K>
195 struct kth_element_type<packed_pixel<BitField, ChannelRefs, Layout>, K>
197 using type = typename channel_traits<mp11::mp_at_c<ChannelRefs, K>>::value_type;
200 template <typename BitField, typename ChannelRefs, typename Layout, int K>
201 struct kth_element_reference_type<packed_pixel<BitField, ChannelRefs, Layout>, K>
203 using type = typename channel_traits<mp11::mp_at_c<ChannelRefs, K>>::reference;
206 template <typename BitField, typename ChannelRefs, typename Layout, int K>
207 struct kth_element_const_reference_type<packed_pixel<BitField, ChannelRefs, Layout>, K>
209 using type = typename channel_traits<mp11::mp_at_c<ChannelRefs, K>>::const_reference;
212 template <int K, typename P, typename C, typename L>
214 auto at_c(packed_pixel<P, C, L>& p)
215 -> typename kth_element_reference_type<packed_pixel<P, C, L>, K>::type
217 return typename kth_element_reference_type
219 packed_pixel<P, C, L>,
221 >::type{&p._bitfield};
224 template <int K, typename P, typename C, typename L>
226 auto at_c(const packed_pixel<P, C, L>& p)
227 -> typename kth_element_const_reference_type<packed_pixel<P, C, L>, K>::type
229 return typename kth_element_const_reference_type
231 packed_pixel<P, C, L>,
232 K>::type{&p._bitfield};
235 /////////////////////////////
237 /////////////////////////////
239 // Metafunction predicate that flags packed_pixel as a model of PixelConcept. Required by PixelConcept
240 template <typename BitField, typename ChannelRefs, typename Layout>
241 struct is_pixel<packed_pixel<BitField, ChannelRefs, Layout>> : std::true_type {};
243 /////////////////////////////
245 /////////////////////////////
247 template <typename P, typename C, typename Layout>
248 struct color_space_type<packed_pixel<P, C, Layout>>
250 using type = typename Layout::color_space_t;
253 template <typename P, typename C, typename Layout>
254 struct channel_mapping_type<packed_pixel<P, C, Layout>>
256 using type = typename Layout::channel_mapping_t;
259 template <typename P, typename C, typename Layout>
260 struct is_planar<packed_pixel<P, C, Layout>> : std::false_type {};
262 ////////////////////////////////////////////////////////////////////////////////
263 /// Support for interleaved iterators over packed pixel
264 ////////////////////////////////////////////////////////////////////////////////
266 /// \defgroup PixelIteratorModelPackedInterleavedPtr Pointer to packed_pixel<P,CR,Layout>
267 /// \ingroup PixelIteratorModel
268 /// \brief Iterators over interleaved pixels.
269 /// The pointer packed_pixel<P,CR,Layout>* is used as an iterator over interleaved pixels of packed format. Models PixelIteratorConcept, HasDynamicXStepTypeConcept, MemoryBasedIteratorConcept
271 template <typename P, typename C, typename L>
272 struct iterator_is_mutable<packed_pixel<P, C, L>*>
273 : std::integral_constant<bool, packed_pixel<P, C, L>::is_mutable>
276 template <typename P, typename C, typename L>
277 struct iterator_is_mutable<const packed_pixel<P, C, L>*> : std::false_type {};
279 }} // namespace boost::gil