boost/gil/packed_pixel.hpp
/*
Copyright 2005-2007 Adobe Systems Incorporated
Use, modification and distribution are subject to the Boost Software License,
Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
http://www.boost.org/LICENSE_1_0.txt).
See http://opensource.adobe.com/gil for most recent version including documentation.
*/
/*************************************************************************************************/
#ifndef GIL_PACKED_PIXEL_H
#define GIL_PACKED_PIXEL_H
////////////////////////////////////////////////////////////////////////////////////////
/// \file
/// \brief A model of a heterogeneous pixel whose channels are bit ranges. For example 16-bit RGB in '565' format
/// \author Lubomir Bourdev and Hailin Jin \n
/// Adobe Systems Incorporated
/// \date 2005-2007 \n Last updated on September 28, 2006
///
////////////////////////////////////////////////////////////////////////////////////////
#include <functional>
#include <boost/utility/enable_if.hpp>
#include <boost/mpl/bool.hpp>
#include <boost/mpl/front.hpp>
#include "gil_config.hpp"
#include "pixel.hpp"
namespace boost { namespace gil {
/// \defgroup ColorBaseModelPackedPixel packed_pixel
/// \ingroup ColorBaseModel
/// \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.
/**
\defgroup PixelModelPackedPixel packed_pixel
\ingroup PixelModel
\brief A heterogeneous pixel used to represent packed pixels with non-byte-aligned channels. Models PixelValueConcept
Example:
\code
typedef packed_pixel_type<uint16_t, mpl::vector3_c<unsigned,5,6,5>, rgb_layout_t>::type rgb565_pixel_t;
BOOST_STATIC_ASSERT((sizeof(rgb565_pixel_t)==2));
rgb565_pixel_t r565;
get_color(r565,red_t()) = 31;
get_color(r565,green_t()) = 63;
get_color(r565,blue_t()) = 31;
assert(r565 == rgb565_pixel_t((uint16_t)0xFFFF));
\endcode
*/
/// \ingroup ColorBaseModelPackedPixel PixelModelPackedPixel PixelBasedModel
/// \brief Heterogeneous pixel value whose channel references can be constructed from the pixel bitfield and their index. Models ColorBaseValueConcept, PixelValueConcept, PixelBasedConcept
/// Typical use for this is a model of a packed pixel (like 565 RGB)
template <typename BitField, // A type that holds the bits of the pixel. Typically an integral type, like boost::uint16_t
typename ChannelRefVec, // An MPL vector whose elements are packed channels. They must be constructible from BitField. GIL uses packed_channel_reference
typename Layout> // Layout defining the color space and ordering of the channels. Example value: rgb_layout_t
struct packed_pixel {
BitField _bitfield;
typedef Layout layout_t;
typedef packed_pixel value_type;
typedef value_type& reference;
typedef const value_type& const_reference;
BOOST_STATIC_CONSTANT(bool, is_mutable = channel_traits<typename mpl::front<ChannelRefVec>::type>::is_mutable);
packed_pixel(){}
explicit packed_pixel(const BitField& bitfield) : _bitfield(bitfield) {}
// Construct from another compatible pixel type
packed_pixel(const packed_pixel& p) : _bitfield(p._bitfield) {}
template <typename P> packed_pixel(const P& p, typename enable_if_c<is_pixel<P>::value>::type* d=0) { check_compatible<P>(); static_copy(p,*this); }
packed_pixel(int chan0, int chan1) : _bitfield(0) {
BOOST_STATIC_ASSERT((num_channels<packed_pixel>::value==2));
at_c<0>(*this)=chan0; at_c<1>(*this)=chan1;
}
packed_pixel(int chan0, int chan1, int chan2) : _bitfield(0) {
BOOST_STATIC_ASSERT((num_channels<packed_pixel>::value==3));
at_c<0>(*this)=chan0; at_c<1>(*this)=chan1; at_c<2>(*this)=chan2;
}
packed_pixel(int chan0, int chan1, int chan2, int chan3) : _bitfield(0) {
BOOST_STATIC_ASSERT((num_channels<packed_pixel>::value==4));
at_c<0>(*this)=chan0; at_c<1>(*this)=chan1; at_c<2>(*this)=chan2; at_c<2>(*this)=chan3;
}
packed_pixel(int chan0, int chan1, int chan2, int chan3, int chan4) : _bitfield(0) {
BOOST_STATIC_ASSERT((num_channels<packed_pixel>::value==5));
at_c<0>(*this)=chan0; at_c<1>(*this)=chan1; at_c<2>(*this)=chan2; at_c<2>(*this)=chan3; at_c<3>(*this)=chan4;
}
packed_pixel& operator=(const packed_pixel& p) { _bitfield=p._bitfield; return *this; }
template <typename P> packed_pixel& operator=(const P& p) { assign(p, mpl::bool_<is_pixel<P>::value>()); return *this; }
template <typename P> bool operator==(const P& p) const { return equal(p, mpl::bool_<is_pixel<P>::value>()); }
template <typename P> bool operator!=(const P& p) const { return !(*this==p); }
private:
template <typename Pixel> static void check_compatible() { gil_function_requires<PixelsCompatibleConcept<Pixel,packed_pixel> >(); }
template <typename Pixel> void assign(const Pixel& p, mpl::true_) { check_compatible<Pixel>(); static_copy(p,*this); }
template <typename Pixel> bool equal(const Pixel& p, mpl::true_) const { check_compatible<Pixel>(); return static_equal(*this,p); }
// Support for assignment/equality comparison of a channel with a grayscale pixel
static void check_gray() { BOOST_STATIC_ASSERT((is_same<typename Layout::color_space_t, gray_t>::value)); }
template <typename Channel> void assign(const Channel& chan, mpl::false_) { check_gray(); at_c<0>(*this)=chan; }
template <typename Channel> bool equal (const Channel& chan, mpl::false_) const { check_gray(); return at_c<0>(*this)==chan; }
public:
packed_pixel& operator= (int chan) { check_gray(); at_c<0>(*this)=chan; return *this; }
bool operator==(int chan) const { check_gray(); return at_c<0>(*this)==chan; }
};
/////////////////////////////
// ColorBasedConcept
/////////////////////////////
template <typename BitField, typename ChannelRefVec, typename Layout, int K>
struct kth_element_type<packed_pixel<BitField,ChannelRefVec,Layout>,K> : public mpl::at_c<ChannelRefVec,K> {};
template <typename BitField, typename ChannelRefVec, typename Layout, int K>
struct kth_element_reference_type<packed_pixel<BitField,ChannelRefVec,Layout>,K> : public mpl::at_c<ChannelRefVec,K> {};
template <typename BitField, typename ChannelRefVec, typename Layout, int K>
struct kth_element_const_reference_type<packed_pixel<BitField,ChannelRefVec,Layout>,K> {
typedef typename channel_traits<typename mpl::at_c<ChannelRefVec,K>::type>::const_reference type;
};
template <int K, typename P, typename C, typename L> inline
typename kth_element_reference_type<packed_pixel<P,C,L>, K>::type
at_c(packed_pixel<P,C,L>& p) {
return typename kth_element_reference_type<packed_pixel<P,C,L>, K>::type(&p._bitfield);
}
template <int K, typename P, typename C, typename L> inline
typename kth_element_const_reference_type<packed_pixel<P,C,L>, K>::type
at_c(const packed_pixel<P,C,L>& p) {
return typename kth_element_const_reference_type<packed_pixel<P,C,L>, K>::type(&p._bitfield);
}
/////////////////////////////
// PixelConcept
/////////////////////////////
// Metafunction predicate that flags packed_pixel as a model of PixelConcept. Required by PixelConcept
template <typename BitField, typename ChannelRefVec, typename Layout>
struct is_pixel<packed_pixel<BitField,ChannelRefVec,Layout> > : public mpl::true_{};
/////////////////////////////
// PixelBasedConcept
/////////////////////////////
template <typename P, typename C, typename Layout>
struct color_space_type<packed_pixel<P,C,Layout> > {
typedef typename Layout::color_space_t type;
};
template <typename P, typename C, typename Layout>
struct channel_mapping_type<packed_pixel<P,C,Layout> > {
typedef typename Layout::channel_mapping_t type;
};
template <typename P, typename C, typename Layout>
struct is_planar<packed_pixel<P,C,Layout> > : mpl::false_ {};
////////////////////////////////////////////////////////////////////////////////
///
/// Support for interleaved iterators over packed pixel
///
////////////////////////////////////////////////////////////////////////////////
/// \defgroup PixelIteratorModelPackedInterleavedPtr Pointer to packed_pixel<P,CR,Layout>
/// \ingroup PixelIteratorModel
/// \brief Iterators over interleaved pixels.
/// The pointer packed_pixel<P,CR,Layout>* is used as an iterator over interleaved pixels of packed format. Models PixelIteratorConcept, HasDynamicXStepTypeConcept, MemoryBasedIteratorConcept
template <typename P, typename C, typename L>
struct iterator_is_mutable<packed_pixel<P,C,L>*> : public mpl::bool_<packed_pixel<P,C,L>::is_mutable> {};
template <typename P, typename C, typename L>
struct iterator_is_mutable<const packed_pixel<P,C,L>*> : public mpl::false_ {};
} } // namespace boost::gil
namespace boost {
template <typename P, typename C, typename L>
struct has_trivial_constructor<gil::packed_pixel<P,C,L> > : public has_trivial_constructor<P> {};
}
#endif
