8 #ifndef BOOST_GIL_VIRTUAL_LOCATOR_HPP     9 #define BOOST_GIL_VIRTUAL_LOCATOR_HPP    11 #include <boost/gil/dynamic_step.hpp>    12 #include <boost/gil/position_iterator.hpp>    14 #include <boost/assert.hpp>    15 #include <boost/iterator/iterator_facade.hpp>    17 namespace boost { 
namespace gil {
    31 template <
typename DerefFn, 
bool IsTransposed>
    35             virtual_2d_locator<DerefFn, IsTransposed>,
    36             position_iterator<DerefFn, IsTransposed>,
    37             position_iterator<DerefFn, 1-IsTransposed>
    49     using deref_fn_t = DerefFn;
    51     using coord_t = 
typename parent_t::coord_t;
    52     using x_coord_t = 
typename parent_t::x_coord_t;
    53     using y_coord_t = 
typename parent_t::y_coord_t;
    57     template <
typename NewDerefFn>
    62         static type make(
this_t const& loc, NewDerefFn 
const& new_deref_fn)
    64             return type(loc.pos(), loc.step(),
    70         point_t 
const& p = {0, 0},
    71         point_t 
const& step = {1, 1},
    72         deref_fn_t 
const& deref_fn = deref_fn_t())
    73         : y_pos_(p, step, deref_fn)
    76     template <
typename D, 
bool TR>
    78         : y_pos_(loc.pos(), point_t(loc.step().x, loc.step().y * y_step), loc.deref_fn())
    81     template <
typename D, 
bool TR>
    85             point_t(loc.step().x * y_step, loc.step().y * x_step) :
    86             point_t(loc.step().x * x_step, loc.step().y * y_step)
    89         BOOST_ASSERT(transpose == (IsTransposed != TR));
    92     template <
typename D, 
bool TR>
    98     bool operator==(
const this_t& p)
 const { 
return y_pos_ == p.y_pos_; }
   100     auto x() -> x_iterator&
   102         return *gil_reinterpret_cast<x_iterator*>(
this);
   105     auto x() 
const -> x_iterator 
const&
   107         return *gil_reinterpret_cast_c<x_iterator const*>(
this);
   110     auto y() -> y_iterator& { 
return y_pos_; }
   111     auto y() 
const -> y_iterator 
const& { 
return y_pos_; }
   116         return (it2.pos()[1 - IsTransposed] - pos()[1 - IsTransposed])
   117                 / step()[1 - IsTransposed];
   125     auto pos() const -> 
point_t const& { 
return y_pos_.pos(); }
   126     auto step() const -> point_t const& { 
return y_pos_.step(); }
   127     auto deref_fn() const -> deref_fn_t const& { 
return y_pos_.deref_fn(); }
   130     template <
typename D, 
bool TR>
   131     friend class virtual_2d_locator;
   140 template <
typename D, 
bool TR>
   141 struct channel_type<virtual_2d_locator<D, TR>>
   142     : channel_type<typename virtual_2d_locator<D, TR>::parent_t>
   146 template <
typename D, 
bool TR>
   147 struct color_space_type<virtual_2d_locator<D, TR>>
   148     : color_space_type<typename virtual_2d_locator<D, TR>::parent_t>
   152 template <
typename D, 
bool TR>
   153 struct channel_mapping_type<virtual_2d_locator<D, TR>>
   154     : channel_mapping_type<typename virtual_2d_locator<D, TR>::parent_t>
   158 template <
typename D, 
bool TR>
   159 struct is_planar<virtual_2d_locator<D, TR>>
   160     : is_planar<typename virtual_2d_locator<D, TR>::parent_t>
   168 template <
typename D, 
bool TR>
   169 struct dynamic_x_step_type<virtual_2d_locator<D,TR>>
   171     using type = virtual_2d_locator<D,TR>;
   178 template <
typename D, 
bool TR>
   179 struct dynamic_y_step_type<virtual_2d_locator<D,TR>>
   181     using type = virtual_2d_locator<D,TR>;
   188 template <
typename D, 
bool IsTransposed>
   189 struct transposed_type<virtual_2d_locator<D,IsTransposed>>
   191     using type = virtual_2d_locator<D,1-IsTransposed>;
 base class for models of PixelLocatorConceptPixel locator is similar to a pixel iterator,...
Definition: locator.hpp:109
An iterator that remembers its current X,Y position and invokes a function object with it upon derefe...
Definition: position_iterator.hpp:31
A 2D locator over a virtual image Upon dereferencing, invokes a given function object passing it its ...
Definition: virtual_locator.hpp:32
auto y_distance_to(this_t const &it2, x_coord_t) const -> y_coord_t
Returns the y distance between two x_iterators given the difference of their x positions.
Definition: virtual_locator.hpp:114
bool is_1d_traversable(x_coord_t) const
Definition: virtual_locator.hpp:122
Composes two dereference function objects. Similar to std::unary_compose but needs to pull some alias...
Definition: utilities.hpp:121
2D point both axes of which have the same dimension typeModels: Point2DConcept
Definition: locator.hpp:28