1 | /* |
2 | Copyright 2005-2007 Adobe Systems Incorporated |
3 | |
4 | Use, modification and distribution are subject to the Boost Software License, |
5 | Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at |
6 | http://www.boost.org/LICENSE_1_0.txt). |
7 | |
8 | See http://opensource.adobe.com/gil for most recent version including documentation. |
9 | */ |
10 | /*************************************************************************************************/ |
11 | |
12 | #ifndef GIL_IMAGE_VIEW_H |
13 | #define GIL_IMAGE_VIEW_H |
14 | |
15 | //////////////////////////////////////////////////////////////////////////////////////// |
16 | /// \file |
17 | /// \brief image view class |
18 | /// \author Lubomir Bourdev and Hailin Jin \n |
19 | /// Adobe Systems Incorporated |
20 | /// \date 2005-2007 \n Last updated on February 12, 2007 |
21 | /// |
22 | //////////////////////////////////////////////////////////////////////////////////////// |
23 | |
24 | #include <cstddef> |
25 | #include <iterator> |
26 | #include "gil_config.hpp" |
27 | #include "iterator_from_2d.hpp" |
28 | |
29 | //#ifdef _MSC_VER |
30 | //#pragma warning(push) |
31 | //#pragma warning(disable : 4244) // conversion from 'gil::image<V,Alloc>::coord_t' to 'int', possible loss of data (visual studio compiler doesn't realize that the two types are the same) |
32 | //#endif |
33 | |
34 | namespace boost { namespace gil { |
35 | |
36 | //////////////////////////////////////////////////////////////////////////////////////// |
37 | /// \class image_view |
38 | /// \ingroup ImageViewModel PixelBasedModel |
39 | /// \brief A lightweight object that interprets memory as a 2D array of pixels. Models ImageViewConcept,PixelBasedConcept,HasDynamicXStepTypeConcept,HasDynamicYStepTypeConcept,HasTransposedTypeConcept |
40 | /// |
41 | /// Image view consists of a pixel 2D locator (defining the mechanism for navigating in 2D) |
42 | /// and the image dimensions. |
43 | /// |
44 | /// Image views to images are what ranges are to STL containers. They are lightweight objects, |
45 | /// that don't own the pixels. It is the user's responsibility that the underlying data remains |
46 | /// valid for the lifetime of the image view. |
47 | /// |
48 | /// Similar to iterators and ranges, constness of views does not extend to constness of pixels. |
49 | /// A const \p image_view does not allow changing its location in memory (resizing, moving) but does |
50 | /// not prevent one from changing the pixels. The latter requires an image view whose value_type |
51 | /// is const. |
52 | /// |
53 | /// Images have interfaces consistent with STL 1D random access containers, so they can be used |
54 | /// directly in STL algorithms like: |
55 | /// \code |
56 | /// std::fill(img.begin(), img.end(), red_pixel); |
57 | /// \endcode |
58 | /// |
59 | /// In addition, horizontal, vertical and 2D random access iterators are provided. |
60 | /// |
61 | /// Note also that \p image_view does not require that its element type be a pixel. It could be |
62 | /// instantiated with a locator whose \p value_type models only \p Regular. In this case the image |
63 | /// view models the weaker RandomAccess2DImageViewConcept, and does not model PixelBasedConcept. |
64 | /// Many generic algorithms don't require the elements to be pixels. |
65 | /// |
66 | //////////////////////////////////////////////////////////////////////////////////////// |
67 | template <typename Loc> // Models 2D Pixel Locator |
68 | class image_view { |
69 | public: |
70 | |
71 | // typedefs required by ConstRandomAccessNDImageViewConcept |
72 | static const std::size_t num_dimensions=2; |
73 | typedef typename Loc::value_type value_type; |
74 | typedef typename Loc::reference reference; // result of dereferencing |
75 | typedef typename Loc::coord_t coord_t; // 1D difference type (same for all dimensions) |
76 | typedef coord_t difference_type; // result of operator-(1d_iterator,1d_iterator) |
77 | typedef typename Loc::point_t point_t; |
78 | typedef Loc locator; |
79 | typedef image_view<typename Loc::const_t> const_t; // same as this type, but over const values |
80 | template <std::size_t D> struct axis { |
81 | typedef typename Loc::template axis<D>::coord_t coord_t; // difference_type along each dimension |
82 | typedef typename Loc::template axis<D>::iterator iterator; // 1D iterator type along each dimension |
83 | }; |
84 | typedef iterator_from_2d<Loc> iterator; // 1D iterator type for each pixel left-to-right inside top-to-bottom |
85 | typedef std::reverse_iterator<iterator> reverse_iterator; |
86 | typedef std::size_t size_type; |
87 | |
88 | // typedefs required by ConstRandomAccess2DImageViewConcept |
89 | typedef locator xy_locator; |
90 | typedef typename xy_locator::x_iterator x_iterator; // pixel iterator along a row |
91 | typedef typename xy_locator::y_iterator y_iterator; // pixel iterator along a column |
92 | typedef typename xy_locator::x_coord_t x_coord_t; |
93 | typedef typename xy_locator::y_coord_t y_coord_t; |
94 | |
95 | template <typename Deref> struct add_deref { |
96 | typedef image_view<typename Loc::template add_deref<Deref>::type> type; |
97 | static type make(const image_view<Loc>& iv, const Deref& d) { return type(iv.dimensions(), Loc::template add_deref<Deref>::make(iv.pixels(),d)); } |
98 | }; |
99 | |
100 | image_view() : _dimensions(0,0) {} |
101 | template <typename View> image_view(const View& iv) : _dimensions(iv.dimensions()), _pixels(iv.pixels()) {} |
102 | |
103 | template <typename L2> image_view(const point_t& sz , const L2& loc) : _dimensions(sz), _pixels(loc) {} |
104 | template <typename L2> image_view(coord_t width, coord_t height, const L2& loc) : _dimensions(x_coord_t(width),y_coord_t(height)), _pixels(loc) {} |
105 | |
106 | template <typename View> image_view& operator=(const View& iv) { _pixels=iv.pixels(); _dimensions=iv.dimensions(); return *this; } |
107 | image_view& operator=(const image_view& iv) { _pixels=iv.pixels(); _dimensions=iv.dimensions(); return *this; } |
108 | |
109 | template <typename View> bool operator==(const View& v) const { return pixels()==v.pixels() && dimensions()==v.dimensions(); } |
110 | template <typename View> bool operator!=(const View& v) const { return !(*this==v); } |
111 | |
112 | template <typename L2> friend void swap(image_view<L2>& x, image_view<L2>& y); |
113 | |
114 | const point_t& dimensions() const { return _dimensions; } |
115 | const locator& pixels() const { return _pixels; } |
116 | x_coord_t width() const { return dimensions().x; } |
117 | y_coord_t height() const { return dimensions().y; } |
118 | std::size_t num_channels() const { return gil::num_channels<value_type>::value; } |
119 | bool is_1d_traversable() const { return _pixels.is_1d_traversable(width()); } |
120 | |
121 | //\{@ |
122 | /// \name 1D navigation |
123 | size_type size() const { return width()*height(); } |
124 | iterator begin() const { return iterator(_pixels,_dimensions.x); } |
125 | iterator end() const { return begin()+(difference_type)size(); } // potential performance problem! |
126 | reverse_iterator rbegin() const { return reverse_iterator(end()); } |
127 | reverse_iterator rend() const { return reverse_iterator(begin()); } |
128 | reference operator[](difference_type i) const { return begin()[i]; } // potential performance problem! |
129 | iterator at(difference_type i)const { return begin()+i; } |
130 | iterator at(const point_t& p) const { return begin()+p.y*width()+p.x; } |
131 | iterator at(x_coord_t x, y_coord_t y)const { return begin()+y*width()+x; } |
132 | |
133 | //\}@ |
134 | |
135 | //\{@ |
136 | /// \name 2-D navigation |
137 | reference operator()(const point_t& p) const { return _pixels(p.x,p.y); } |
138 | reference operator()(x_coord_t x, y_coord_t y)const { return _pixels(x,y); } |
139 | template <std::size_t D> typename axis<D>::iterator axis_iterator(const point_t& p) const { return _pixels.axis_iterator<D>(p); } |
140 | xy_locator xy_at(x_coord_t x, y_coord_t y) const { return _pixels+point_t(x_coord_t(x),y_coord_t(y)); } |
141 | locator xy_at(const point_t& p) const { return _pixels+p; } |
142 | //\}@ |
143 | |
144 | //\{@ |
145 | /// \name X navigation |
146 | x_iterator x_at(x_coord_t x, y_coord_t y) const { return _pixels.x_at(x,y); } |
147 | x_iterator x_at(const point_t& p) const { return _pixels.x_at(p); } |
148 | x_iterator row_begin(y_coord_t y) const { return x_at(0,y); } |
149 | x_iterator row_end(y_coord_t y) const { return x_at(width(),y); } |
150 | //\}@ |
151 | |
152 | //\{@ |
153 | /// \name Y navigation |
154 | y_iterator y_at(x_coord_t x, y_coord_t y) const { return xy_at(x,y).y(); } |
155 | y_iterator y_at(const point_t& p) const { return xy_at(p).y(); } |
156 | y_iterator col_begin(x_coord_t x) const { return y_at(x,0); } |
157 | y_iterator col_end(x_coord_t x) const { return y_at(x,height()); } |
158 | //\}@ |
159 | |
160 | private: |
161 | template <typename L2> friend class image_view; |
162 | |
163 | point_t _dimensions; |
164 | xy_locator _pixels; |
165 | }; |
166 | |
167 | template <typename L2> |
168 | inline void swap(image_view<L2>& x, image_view<L2>& y) { |
169 | using std::swap; |
170 | swap(x._dimensions,y._dimensions); |
171 | swap(x._pixels, y._pixels); // TODO: Extend further |
172 | } |
173 | |
174 | ///////////////////////////// |
175 | // PixelBasedConcept |
176 | ///////////////////////////// |
177 | |
178 | template <typename L> |
179 | struct channel_type<image_view<L> > : public channel_type<L> {}; |
180 | |
181 | template <typename L> |
182 | struct color_space_type<image_view<L> > : public color_space_type<L> {}; |
183 | |
184 | template <typename L> |
185 | struct channel_mapping_type<image_view<L> > : public channel_mapping_type<L> {}; |
186 | |
187 | template <typename L> |
188 | struct is_planar<image_view<L> > : public is_planar<L> {}; |
189 | |
190 | ///////////////////////////// |
191 | // HasDynamicXStepTypeConcept |
192 | ///////////////////////////// |
193 | |
194 | template <typename L> |
195 | struct dynamic_x_step_type<image_view<L> > { |
196 | typedef image_view<typename dynamic_x_step_type<L>::type> type; |
197 | }; |
198 | |
199 | ///////////////////////////// |
200 | // HasDynamicYStepTypeConcept |
201 | ///////////////////////////// |
202 | |
203 | template <typename L> |
204 | struct dynamic_y_step_type<image_view<L> > { |
205 | typedef image_view<typename dynamic_y_step_type<L>::type> type; |
206 | }; |
207 | |
208 | ///////////////////////////// |
209 | // HasTransposedTypeConcept |
210 | ///////////////////////////// |
211 | |
212 | template <typename L> |
213 | struct transposed_type<image_view<L> > { |
214 | typedef image_view<typename transposed_type<L>::type> type; |
215 | }; |
216 | |
217 | } } // namespace boost::gil |
218 | |
219 | //#ifdef _MSC_VER |
220 | //#pragma warning(pop) |
221 | //#endif |
222 | |
223 | #endif |
224 | |