Edit: /usr/include/boost/gil/virtual_locator.hpp (6288B)
//
// Copyright 2005-2007 Adobe Systems Incorporated
//
// Distributed under 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
//
#ifndef BOOST_GIL_VIRTUAL_LOCATOR_HPP
#define BOOST_GIL_VIRTUAL_LOCATOR_HPP
#include
#include
#include
#include
namespace boost { namespace gil {
/// \ingroup PixelLocatorModel PixelBasedModel
/// \brief A 2D locator over a virtual image
/// Upon dereferencing, invokes a given function object passing it its coordinates.
/// Models:
/// PixelLocatorConcept,
/// HasDynamicXStepTypeConcept,
/// HasDynamicYStepTypeConcept,
/// HasTransposedTypeConcept
///
/// \tparam DerefFn Function object that given a point returns a reference.
/// Models PixelDereferenceAdaptorConcept.
/// \tparam IsTransposed Indicates if locator should navigate in transposed mode.
template
class virtual_2d_locator
: public pixel_2d_locator_base
<
virtual_2d_locator,
position_iterator,
position_iterator
>
{
using this_t = virtual_2d_locator;
public:
using parent_t = pixel_2d_locator_base
<
virtual_2d_locator,
position_iterator,
position_iterator
>;
using const_t = virtual_2d_locator;
using deref_fn_t = DerefFn;
using point_t = typename parent_t::point_t;
using coord_t = typename parent_t::coord_t;
using x_coord_t = typename parent_t::x_coord_t;
using y_coord_t = typename parent_t::y_coord_t;
using x_iterator = typename parent_t::x_iterator;
using y_iterator = typename parent_t::y_iterator;
template
struct add_deref
{
using type = virtual_2d_locator, IsTransposed>;
static type make(this_t const& loc, NewDerefFn const& new_deref_fn)
{
return type(loc.pos(), loc.step(),
deref_compose(new_deref_fn, loc.deref_fn()));
}
};
virtual_2d_locator(
point_t const& p = {0, 0},
point_t const& step = {1, 1},
deref_fn_t const& deref_fn = deref_fn_t())
: y_pos_(p, step, deref_fn)
{}
template
virtual_2d_locator(virtual_2d_locator const &loc, coord_t y_step)
: y_pos_(loc.pos(), point_t(loc.step().x, loc.step().y * y_step), loc.deref_fn())
{}
template
virtual_2d_locator(virtual_2d_locator const& loc, coord_t x_step, coord_t y_step, bool transpose = false)
: y_pos_(loc.pos()
, transpose ?
point_t(loc.step().x * y_step, loc.step().y * x_step) :
point_t(loc.step().x * x_step, loc.step().y * y_step)
, loc.deref_fn())
{
BOOST_ASSERT(transpose == (IsTransposed != TR));
}
template
virtual_2d_locator(virtual_2d_locator const& other) : y_pos_(other.y_pos_) {}
virtual_2d_locator(virtual_2d_locator const& other) : y_pos_(other.y_pos_) {}
virtual_2d_locator& operator=(virtual_2d_locator const& other) = default;
bool operator==(const this_t& p) const { return y_pos_ == p.y_pos_; }
auto x() -> x_iterator&
{
return *gil_reinterpret_cast(this);
}
auto x() const -> x_iterator const&
{
return *gil_reinterpret_cast_c(this);
}
auto y() -> y_iterator& { return y_pos_; }
auto y() const -> y_iterator const& { return y_pos_; }
/// Returns the y distance between two x_iterators given the difference of their x positions
auto y_distance_to(this_t const& it2, x_coord_t) const -> y_coord_t
{
return (it2.pos()[1 - IsTransposed] - pos()[1 - IsTransposed])
/ step()[1 - IsTransposed];
}
/// \todo TODO: is there no gap at the end of each row?
/// i.e. can we use x_iterator to visit every pixel instead of nested loops?
bool is_1d_traversable(x_coord_t) const { return false; }
// Methods specific for virtual 2D locator
auto pos() const -> point_t const& { return y_pos_.pos(); }
auto step() const -> point_t const& { return y_pos_.step(); }
auto deref_fn() const -> deref_fn_t const& { return y_pos_.deref_fn(); }
private:
template
friend class virtual_2d_locator;
y_iterator y_pos_; // current position, the step and the dereference object
};
/////////////////////////////
// PixelBasedConcept
/////////////////////////////
template
struct channel_type>
: channel_type::parent_t>
{
};
template
struct color_space_type>
: color_space_type::parent_t>
{
};
template
struct channel_mapping_type>
: channel_mapping_type::parent_t>
{
};
template
struct is_planar>
: is_planar::parent_t>
{
};
/////////////////////////////
// HasDynamicXStepTypeConcept
/////////////////////////////
template
struct dynamic_x_step_type>
{
using type = virtual_2d_locator;
};
/////////////////////////////
// HasDynamicYStepTypeConcept
/////////////////////////////
template
struct dynamic_y_step_type>
{
using type = virtual_2d_locator;
};
/////////////////////////////
// HasTransposedTypeConcept
/////////////////////////////
template
struct transposed_type>
{
using type = virtual_2d_locator;
};
}} // namespace boost::gil
#endif