/* | |
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://stlab.adobe.com/gil for most recent version including documentation. | |
*/ | |
/*************************************************************************************************/ | |
#ifndef GIL_BIT_ALIGNED_PIXEL_REFERENCE_HPP | |
#define GIL_BIT_ALIGNED_PIXEL_REFERENCE_HPP | |
//////////////////////////////////////////////////////////////////////////////////////// | |
/// \file | |
/// \brief A model of a heterogeneous pixel that is not byte aligned. Examples are bitmap (1-bit pixels) or 6-bit RGB (222) | |
/// \author Lubomir Bourdev and Hailin Jin \n | |
/// Adobe Systems Incorporated | |
/// \date 2005-2007 \n Last updated on September 28, 2006 | |
/// | |
//////////////////////////////////////////////////////////////////////////////////////// | |
#include <functional> | |
#include <boost/mpl/accumulate.hpp> | |
#include <boost/mpl/at.hpp> | |
#include <boost/mpl/bool.hpp> | |
#include <boost/mpl/if.hpp> | |
#include <boost/mpl/plus.hpp> | |
#include <boost/mpl/push_back.hpp> | |
#include <boost/mpl/vector.hpp> | |
#include "gil_config.hpp" | |
#include "pixel.hpp" | |
#include "channel.hpp" | |
namespace boost { namespace gil { | |
///////////////////////////// | |
// bit_range | |
// | |
// Represents a range of bits that can span multiple consecutive bytes. The range has a size fixed at compile time, but the offset is specified at run time. | |
///////////////////////////// | |
template <int RangeSize, bool Mutable> | |
class bit_range { | |
public: | |
typedef typename mpl::if_c<Mutable,unsigned char,const unsigned char>::type byte_t; | |
typedef std::ptrdiff_t difference_type; | |
template <int RS, bool M> friend class bit_range; | |
private: | |
byte_t* _current_byte; // the starting byte of the bit range | |
int _bit_offset; // offset from the beginning of the current byte. 0<=_bit_offset<=7 | |
public: | |
bit_range() : _current_byte(NULL), _bit_offset(0) {} | |
bit_range(byte_t* current_byte, int bit_offset) : _current_byte(current_byte), _bit_offset(bit_offset) { assert(bit_offset>=0 && bit_offset<8); } | |
bit_range(const bit_range& br) : _current_byte(br._current_byte), _bit_offset(br._bit_offset) {} | |
template <bool M> bit_range(const bit_range<RangeSize,M>& br) : _current_byte(br._current_byte), _bit_offset(br._bit_offset) {} | |
bit_range& operator=(const bit_range& br) { _current_byte = br._current_byte; _bit_offset=br._bit_offset; return *this; } | |
bool operator==(const bit_range& br) const { return _current_byte==br._current_byte && _bit_offset==br._bit_offset; } | |
bit_range& operator++() { | |
_current_byte += (_bit_offset+RangeSize) / 8; | |
_bit_offset = (_bit_offset+RangeSize) % 8; | |
return *this; | |
} | |
bit_range& operator--() { bit_advance(-RangeSize); return *this; } | |
void bit_advance(difference_type num_bits) { | |
int new_offset = int(_bit_offset+num_bits); | |
_current_byte += new_offset / 8; | |
_bit_offset = new_offset % 8; | |
if (_bit_offset<0) { | |
_bit_offset+=8; | |
--_current_byte; | |
} | |
} | |
difference_type bit_distance_to(const bit_range& b) const { | |
return (b.current_byte() - current_byte())*8 + b.bit_offset()-bit_offset(); | |
} | |
byte_t* current_byte() const { return _current_byte; } | |
int bit_offset() const { return _bit_offset; } | |
}; | |
/// \defgroup ColorBaseModelNonAlignedPixel bit_aligned_pixel_reference | |
/// \ingroup ColorBaseModel | |
/// \brief A heterogeneous color base representing pixel that may not be byte aligned, i.e. it may correspond to a bit range that does not start/end at a byte boundary. Models ColorBaseConcept. | |
/** | |
\defgroup PixelModelNonAlignedPixel bit_aligned_pixel_reference | |
\ingroup PixelModel | |
\brief A heterogeneous pixel reference used to represent non-byte-aligned pixels. Models PixelConcept | |
Example: | |
\code | |
unsigned char data=0; | |
// A mutable reference to a 6-bit BGR pixel in "123" format (1 bit for red, 2 bits for green, 3 bits for blue) | |
typedef const bit_aligned_pixel_reference<unsigned char, mpl::vector3_c<int,1,2,3>, rgb_layout_t, true> rgb123_ref_t; | |
// create the pixel reference at bit offset 2 | |
// (i.e. red = [2], green = [3,4], blue = [5,6,7] bits) | |
rgb123_ref_t ref(&data, 2); | |
get_color(ref, red_t()) = 1; | |
assert(data == 0x04); | |
get_color(ref, green_t()) = 3; | |
assert(data == 0x1C); | |
get_color(ref, blue_t()) = 7; | |
assert(data == 0xFC); | |
\endcode | |
*/ | |
/// \ingroup ColorBaseModelNonAlignedPixel PixelModelNonAlignedPixel PixelBasedModel | |
/// \brief Heterogeneous pixel reference corresponding to non-byte-aligned bit range. Models ColorBaseConcept, PixelConcept, PixelBasedConcept | |
template <typename BitField, | |
typename ChannelBitSizes, // MPL integral vector defining the number of bits for each channel. For example, for 565RGB, vector_c<int,5,6,5> | |
typename Layout, | |
bool IsMutable> | |
struct bit_aligned_pixel_reference { | |
BOOST_STATIC_CONSTANT(int, bit_size = (mpl::accumulate<ChannelBitSizes, mpl::int_<0>, mpl::plus<mpl::_1, mpl::_2> >::type::value)); | |
typedef boost::gil::bit_range<bit_size,IsMutable> bit_range_t; | |
typedef BitField bitfield_t; | |
typedef typename mpl::if_c<IsMutable,unsigned char*,const unsigned char*>::type data_ptr_t; | |
typedef Layout layout_t; | |
typedef typename packed_pixel_type<bitfield_t,ChannelBitSizes,Layout>::type value_type; | |
typedef const bit_aligned_pixel_reference reference; | |
typedef const bit_aligned_pixel_reference<BitField,ChannelBitSizes,Layout,false> const_reference; | |
BOOST_STATIC_CONSTANT(bool, is_mutable = IsMutable); | |
bit_aligned_pixel_reference(){} | |
bit_aligned_pixel_reference(data_ptr_t data_ptr, int bit_offset) : _bit_range(data_ptr, bit_offset) {} | |
explicit bit_aligned_pixel_reference(const bit_range_t& bit_range) : _bit_range(bit_range) {} | |
template <bool IsMutable2> bit_aligned_pixel_reference(const bit_aligned_pixel_reference<BitField,ChannelBitSizes,Layout,IsMutable2>& p) : _bit_range(p._bit_range) {} | |
// Grayscale references can be constructed from the channel reference | |
explicit bit_aligned_pixel_reference(const typename kth_element_type<bit_aligned_pixel_reference,0>::type channel0) : _bit_range(static_cast<data_ptr_t>(&channel0), channel0.first_bit()) { | |
BOOST_STATIC_ASSERT((num_channels<bit_aligned_pixel_reference>::value==1)); | |
} | |
// Construct from another compatible pixel type | |
bit_aligned_pixel_reference(const bit_aligned_pixel_reference& p) : _bit_range(p._bit_range) {} | |
template <typename BF, typename CR> bit_aligned_pixel_reference(packed_pixel<BF,CR,Layout>& p) : _bit_range(static_cast<data_ptr_t>(&gil::at_c<0>(p)), gil::at_c<0>(p).first_bit()) { | |
check_compatible<packed_pixel<BF,CR,Layout> >(); | |
} | |
const bit_aligned_pixel_reference& operator=(const bit_aligned_pixel_reference& p) const { static_copy(p,*this); return *this; } | |
template <typename P> const bit_aligned_pixel_reference& operator=(const P& p) const { 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); } | |
const bit_aligned_pixel_reference* operator->() const { return this; } | |
const bit_range_t& bit_range() const { return _bit_range; } | |
private: | |
mutable bit_range_t _bit_range; | |
template <typename B, typename C, typename L, bool M> friend struct bit_aligned_pixel_reference; | |
template <typename Pixel> static void check_compatible() { gil_function_requires<PixelsCompatibleConcept<Pixel,bit_aligned_pixel_reference> >(); } | |
template <typename Pixel> void assign(const Pixel& p, mpl::true_) const { 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); } | |
private: | |
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_) const { check_gray(); gil::at_c<0>(*this)=chan; } | |
template <typename Channel> bool equal (const Channel& chan, mpl::false_) const { check_gray(); return gil::at_c<0>(*this)==chan; } | |
}; | |
///////////////////////////// | |
// ColorBasedConcept | |
///////////////////////////// | |
template <typename BitField, typename ChannelBitSizes, typename L, bool IsMutable, int K> | |
struct kth_element_type<bit_aligned_pixel_reference<BitField,ChannelBitSizes,L,IsMutable>, K> { | |
public: | |
typedef const packed_dynamic_channel_reference<BitField, mpl::at_c<ChannelBitSizes,K>::type::value, IsMutable> type; | |
}; | |
template <typename B, typename C, typename L, bool M, int K> | |
struct kth_element_reference_type<bit_aligned_pixel_reference<B,C,L,M>, K> | |
: public kth_element_type<bit_aligned_pixel_reference<B,C,L,M>, K> {}; | |
template <typename B, typename C, typename L, bool M, int K> | |
struct kth_element_const_reference_type<bit_aligned_pixel_reference<B,C,L,M>, K> | |
: public kth_element_type<bit_aligned_pixel_reference<B,C,L,M>, K> {}; | |
namespace detail { | |
// returns sum of IntegralVector[0] ... IntegralVector[K-1] | |
template <typename IntegralVector, int K> | |
struct sum_k : public mpl::plus<sum_k<IntegralVector,K-1>, typename mpl::at_c<IntegralVector,K-1>::type > {}; | |
template <typename IntegralVector> struct sum_k<IntegralVector,0> : public mpl::int_<0> {}; | |
} | |
// at_c required by MutableColorBaseConcept | |
template <int K, typename BitField, typename ChannelBitSizes, typename L, bool Mutable> inline | |
typename kth_element_reference_type<bit_aligned_pixel_reference<BitField,ChannelBitSizes,L,Mutable>,K>::type | |
at_c(const bit_aligned_pixel_reference<BitField,ChannelBitSizes,L,Mutable>& p) { | |
typedef bit_aligned_pixel_reference<BitField,ChannelBitSizes,L,Mutable> pixel_t; | |
typedef typename kth_element_reference_type<pixel_t,K>::type channel_t; | |
typedef typename pixel_t::bit_range_t bit_range_t; | |
bit_range_t bit_range(p.bit_range()); | |
bit_range.bit_advance(detail::sum_k<ChannelBitSizes,K>::value); | |
return channel_t(bit_range.current_byte(), bit_range.bit_offset()); | |
} | |
///////////////////////////// | |
// PixelConcept | |
///////////////////////////// | |
/// Metafunction predicate that flags bit_aligned_pixel_reference as a model of PixelConcept. Required by PixelConcept | |
template <typename B, typename C, typename L, bool M> | |
struct is_pixel<bit_aligned_pixel_reference<B,C,L,M> > : public mpl::true_{}; | |
///////////////////////////// | |
// PixelBasedConcept | |
///////////////////////////// | |
template <typename B, typename C, typename L, bool M> | |
struct color_space_type<bit_aligned_pixel_reference<B,C,L,M> > { | |
typedef typename L::color_space_t type; | |
}; | |
template <typename B, typename C, typename L, bool M> | |
struct channel_mapping_type<bit_aligned_pixel_reference<B,C,L,M> > { | |
typedef typename L::channel_mapping_t type; | |
}; | |
template <typename B, typename C, typename L, bool M> | |
struct is_planar<bit_aligned_pixel_reference<B,C,L,M> > : mpl::false_ {}; | |
///////////////////////////// | |
// pixel_reference_type | |
///////////////////////////// | |
namespace detail { | |
// returns a vector containing K copies of the type T | |
template <unsigned K, typename T> struct k_copies; | |
template <typename T> struct k_copies<0,T> { | |
typedef mpl::vector0<> type; | |
}; | |
template <unsigned K, typename T> struct k_copies : public mpl::push_back<typename k_copies<K-1,T>::type, T> {}; | |
} | |
// Constructs a homogeneous bit_aligned_pixel_reference given a channel reference | |
template <typename BitField, int NumBits, typename Layout> | |
struct pixel_reference_type<const packed_dynamic_channel_reference<BitField,NumBits,false>, Layout, false, false> { | |
private: | |
typedef typename mpl::size<typename Layout::color_space_t>::type size_t; | |
typedef typename detail::k_copies<size_t::value,mpl::integral_c<unsigned,NumBits> >::type channel_bit_sizes_t; | |
public: | |
typedef bit_aligned_pixel_reference<BitField, channel_bit_sizes_t, Layout, false> type; | |
}; | |
// Same but for the mutable case. We cannot combine the mutable and read-only cases because this triggers ambiguity | |
template <typename BitField, int NumBits, typename Layout> | |
struct pixel_reference_type<const packed_dynamic_channel_reference<BitField,NumBits,true>, Layout, false, true> { | |
private: | |
typedef typename mpl::size<typename Layout::color_space_t>::type size_t; | |
typedef typename detail::k_copies<size_t::value,mpl::integral_c<unsigned,NumBits> >::type channel_bit_sizes_t; | |
public: | |
typedef bit_aligned_pixel_reference<BitField, channel_bit_sizes_t, Layout, true> type; | |
}; | |
} } // namespace boost::gil | |
namespace std { | |
// We are forced to define swap inside std namespace because on some platforms (Visual Studio 8) STL calls swap qualified. | |
// swap with 'left bias': | |
// - swap between proxy and anything | |
// - swap between value type and proxy | |
// - swap between proxy and proxy | |
// Having three overloads allows us to swap between different (but compatible) models of PixelConcept | |
template <typename B, typename C, typename L, typename R> inline | |
void swap(const boost::gil::bit_aligned_pixel_reference<B,C,L,true> x, R& y) { | |
boost::gil::swap_proxy<typename boost::gil::bit_aligned_pixel_reference<B,C,L,true>::value_type>(x,y); | |
} | |
template <typename B, typename C, typename L> inline | |
void swap(typename boost::gil::bit_aligned_pixel_reference<B,C,L,true>::value_type& x, const boost::gil::bit_aligned_pixel_reference<B,C,L,true> y) { | |
boost::gil::swap_proxy<typename boost::gil::bit_aligned_pixel_reference<B,C,L,true>::value_type>(x,y); | |
} | |
template <typename B, typename C, typename L> inline | |
void swap(const boost::gil::bit_aligned_pixel_reference<B,C,L,true> x, const boost::gil::bit_aligned_pixel_reference<B,C,L,true> y) { | |
boost::gil::swap_proxy<typename boost::gil::bit_aligned_pixel_reference<B,C,L,true>::value_type>(x,y); | |
} | |
} // namespace std | |
#endif |