c074b00347c34160ea1bee9e6da0bb5f25128c7e
1 #ifndef LIBNR_NR_RECT_H_SEEN
2 #define LIBNR_NR_RECT_H_SEEN
4 /** \file
5 * Definitions of NRRect and NR::Rect types, and some associated functions \& macros.
6 */
7 /*
8 * Authors:
9 * Lauris Kaplinski <lauris@kaplinski.com>
10 * Nathan Hurst <njh@mail.csse.monash.edu.au>
11 * MenTaLguY <mental@rydia.net>
12 *
13 * This code is in public domain
14 */
17 #include <stdexcept>
18 #include <limits>
20 #include "libnr/nr-values.h"
21 #include <libnr/nr-coord.h>
22 #include <libnr/nr-i-coord.h>
23 #include <libnr/nr-dim2.h>
24 #include <libnr/nr-point.h>
25 #include <boost/optional.hpp>
26 #include <libnr/nr-point-matrix-ops.h>
27 #include <libnr/nr-forward.h>
28 #include <2geom/rect.h>
30 namespace NR {
32 /** A rectangle is always aligned to the X and Y axis. This means it
33 * can be defined using only 4 coordinates, and determining
34 * intersection is very efficient. The points inside a rectangle are
35 * min[dim] <= _pt[dim] <= max[dim]. A rectangle may be empty, in the
36 * sense of having zero area, but it will always contain at least one
37 * point. Infinities are also permitted.
38 */
39 class Rect {
40 public:
41 Rect() : _min(-_inf(), -_inf()), _max(_inf(), _inf()) {}
42 Rect(Point const &p0, Point const &p1);
44 Point const &min() const { return _min; }
45 Point const &max() const { return _max; }
47 /** returns the four corners of the rectangle in order
48 * (clockwise if +Y is up, anticlockwise if +Y is down) */
49 Point corner(unsigned i) const;
51 /** returns a vector from min to max. */
52 Point dimensions() const;
54 /** returns the midpoint of this rect. */
55 Point midpoint() const;
57 Point cornerFarthestFrom(Point const &p) const;
59 /** True iff either width or height is less than \a epsilon. */
60 bool isEmpty(double epsilon=1e-6) const {
61 return isEmpty<X>(epsilon) || isEmpty<Y>(epsilon);
62 }
64 bool intersects(Rect const &r) const {
65 return intersects<X>(r) && intersects<Y>(r);
66 }
67 bool contains(Rect const &r) const {
68 return contains<X>(r) && contains<Y>(r);
69 }
70 bool contains(Point const &p) const {
71 return contains<X>(p) && contains<Y>(p);
72 }
74 double area() const {
75 return extent<X>() * extent<Y>();
76 }
78 double maxExtent() const {
79 return MAX(extent<X>(), extent<Y>());
80 }
82 double extent(Dim2 const axis) const {
83 switch (axis) {
84 case X: return extent<X>();
85 case Y: return extent<Y>();
86 default: g_error("invalid axis value %d", (int) axis); return 0;
87 };
88 }
90 double extent(unsigned i) const throw(std::out_of_range) {
91 switch (i) {
92 case 0: return extent<X>();
93 case 1: return extent<Y>();
94 default: throw std::out_of_range("Dimension out of range");
95 };
96 }
98 /**
99 \brief Remove some precision from the Rect
100 \param places The number of decimal places left in the end
102 This function just calls round on the \c _min and \c _max points.
103 */
104 inline void round(int places = 0) {
105 _min.round(places);
106 _max.round(places);
107 return;
108 }
110 /** Translates the rectangle by p. */
111 void offset(Point p);
113 /** Makes this rectangle large enough to include the point p. */
114 void expandTo(Point p);
116 /** Makes this rectangle large enough to include the rectangle r. */
117 void expandTo(Rect const &r);
119 inline void move_left (gdouble by) {
120 _min[NR::X] += by;
121 }
122 inline void move_right (gdouble by) {
123 _max[NR::X] += by;
124 }
125 inline void move_top (gdouble by) {
126 _min[NR::Y] += by;
127 }
128 inline void move_bottom (gdouble by) {
129 _max[NR::Y] += by;
130 }
132 void growBy (gdouble by);
134 /** Scales the rect by s, with origin at 0, 0 */
135 inline Rect operator*(double const s) const {
136 return Rect(s * min(), s * max());
137 }
139 /** Transforms the rect by m. Note that it gives correct results only for scales and translates */
140 inline Rect operator*(Matrix const m) const {
141 return Rect(_min * m, _max * m);
142 }
144 inline bool operator==(Rect const &in_rect) {
145 return ((this->min() == in_rect.min()) && (this->max() == in_rect.max()));
146 }
148 friend inline std::ostream &operator<<(std::ostream &out_file, NR::Rect const &in_rect);
150 private:
151 // Rect(Nothing) : _min(1, 1), _max(-1, -1) {}
153 static double _inf() {
154 return std::numeric_limits<double>::infinity();
155 }
157 template <NR::Dim2 axis>
158 double extent() const {
159 return _max[axis] - _min[axis];
160 }
162 template <NR::Dim2 axis>
163 bool isEmpty(double epsilon) const {
164 return extent<axis>() < epsilon;
165 }
167 template <Dim2 axis>
168 bool intersects(Rect const &r) const {
169 return _max[axis] >= r._min[axis] && _min[axis] <= r._max[axis];
170 }
172 template <Dim2 axis>
173 bool contains(Rect const &r) const {
174 return contains(r._min) && contains(r._max);
175 }
177 template <Dim2 axis>
178 bool contains(Point const &p) const {
179 return p[axis] >= _min[axis] && p[axis] <= _max[axis];
180 }
182 Point _min, _max;
184 friend boost::optional<Rect> intersection(boost::optional<Rect> const &, boost::optional<Rect> const &);
185 friend Rect union_bounds(Rect const &, Rect const &);
186 };
188 /** Returns the set of points shared by both rectangles. */
189 boost::optional<Rect> intersection(boost::optional<Rect> const & a, boost::optional<Rect> const & b);
191 /** Returns the smallest rectangle that encloses both rectangles. */
192 Rect union_bounds(Rect const &a, Rect const &b);
193 inline Rect union_bounds(boost::optional<Rect> const & a, Rect const &b) {
194 if (a) {
195 return union_bounds(*a, b);
196 } else {
197 return b;
198 }
199 }
200 inline Rect union_bounds(Rect const &a, boost::optional<Rect> const & b) {
201 if (b) {
202 return union_bounds(a, *b);
203 } else {
204 return a;
205 }
206 }
207 inline boost::optional<Rect> union_bounds(boost::optional<Rect> const & a, boost::optional<Rect> const & b)
208 {
209 if (!a) {
210 return b;
211 } else if (!b) {
212 return a;
213 } else {
214 return union_bounds(*a, *b);
215 }
216 }
218 /** A function to print out the rectange if sent to an output
219 stream. */
220 inline std::ostream
221 &operator<<(std::ostream &out_file, NR::Rect const &in_rect)
222 {
223 out_file << "Rectangle:\n";
224 out_file << "\tMin Point -> " << in_rect.min() << "\n";
225 out_file << "\tMax Point -> " << in_rect.max() << "\n";
227 return out_file;
228 }
230 } /* namespace NR */
232 /* legacy rect stuff */
234 /* NULL rect is infinite */
236 struct NRRect {
237 NRRect()
238 : x0(0), y0(0), x1(0), y1(0)
239 {}
240 NRRect(NR::Coord xmin, NR::Coord ymin, NR::Coord xmax, NR::Coord ymax)
241 : x0(xmin), y0(ymin), x1(xmax), y1(ymax)
242 {}
243 explicit NRRect(NR::Rect const &rect);
244 explicit NRRect(boost::optional<NR::Rect> const &rect);
245 operator boost::optional<NR::Rect>() const { return upgrade(); }
246 boost::optional<NR::Rect> upgrade() const;
247 explicit NRRect(Geom::OptRect const &rect);
248 operator Geom::OptRect() const { return upgrade_2geom(); }
249 Geom::OptRect upgrade_2geom() const;
251 NR::Coord x0, y0, x1, y1;
252 };
254 #define nr_rect_d_set_empty(r) (*(r) = NR_RECT_EMPTY)
255 #define nr_rect_l_set_empty(r) (*(r) = NR_RECT_L_EMPTY)
257 /** "Empty" here includes the case of zero width or zero height. */
258 // TODO convert to static overloaded functions (pointer and ref) once performance can be tested:
259 #define nr_rect_d_test_empty_ptr(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
260 #define nr_rect_d_test_empty(r) NR_RECT_DFLS_TEST_EMPTY_REF(r)
262 // TODO convert to static overloaded functions (pointer and ref) once performance can be tested:
263 #define nr_rect_l_test_empty_ptr(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
264 #define nr_rect_l_test_empty(r) NR_RECT_DFLS_TEST_EMPTY_REF(r)
266 #define nr_rect_d_test_intersect(r0,r1) \
267 (!nr_rect_d_test_empty(r0) && !nr_rect_d_test_empty(r1) && \
268 !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
270 // TODO convert to static overloaded functions (pointer and ref) once performance can be tested:
271 #define nr_rect_l_test_intersect_ptr(r0,r1) \
272 (!nr_rect_l_test_empty_ptr(r0) && !nr_rect_l_test_empty_ptr(r1) && \
273 !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
274 #define nr_rect_l_test_intersect(r0,r1) \
275 (!nr_rect_l_test_empty(r0) && !nr_rect_l_test_empty(r1) && \
276 !(!NR_RECT_DFLS_TEST_INTERSECT_REF(r0, r1)))
278 #define nr_rect_d_point_d_test_inside(r,p) ((p) && (!(r) || (!NR_RECT_DF_TEST_EMPTY(r) && NR_RECT_DF_POINT_DF_TEST_INSIDE(r,p))))
279 #define nr_rect_l_point_l_test_inside(r,p) ((p) && (!(r) || (!NR_RECT_DFLS_TEST_EMPTY(r) && NR_RECT_LS_POINT_LS_TEST_INSIDE(r,p))))
280 #define nr_rect_l_test_inside(r,x,y) ((!(r) || (!NR_RECT_DFLS_TEST_EMPTY(r) && NR_RECT_LS_TEST_INSIDE(r,x,y))))
282 // returns minimal rect which covers all of r0 not covered by r1
283 NRRectL *nr_rect_l_subtract(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
285 // returns the area of r
286 NR::ICoord nr_rect_l_area(NRRectL *r);
288 /* NULL values are OK for r0 and r1, but not for d */
289 NRRect *nr_rect_d_intersect(NRRect *d, NRRect const *r0, NRRect const *r1);
290 NRRectL *nr_rect_l_intersect(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
292 NRRect *nr_rect_d_union(NRRect *d, NRRect const *r0, NRRect const *r1);
293 NRRectL *nr_rect_l_union(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
295 NRRect *nr_rect_union_pt(NRRect *dst, NR::Point const &p);
296 NRRect *nr_rect_d_union_xy(NRRect *d, NR::Coord x, NR::Coord y);
297 NRRectL *nr_rect_l_union_xy(NRRectL *d, NR::ICoord x, NR::ICoord y);
299 NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NR::Matrix const &m);
300 NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NR::Matrix const *m);
301 NRRectL *nr_rect_l_enlarge(NRRectL *d, int amount);
304 #endif /* !LIBNR_NR_RECT_H_SEEN */
306 /*
307 Local Variables:
308 mode:c++
309 c-file-style:"stroustrup"
310 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
311 indent-tabs-mode:nil
312 fill-column:99
313 End:
314 */
315 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :