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 <libnr/nr-maybe.h>
26 #include <libnr/nr-point-matrix-ops.h>
28 struct NRRect;
29 struct NRRectL;
31 namespace NR {
32 struct Matrix;
34 /** A rectangle is always aligned to the X and Y axis. This means it
35 * can be defined using only 4 coordinates, and determining
36 * intersection is very efficient. The points inside a rectangle are
37 * min[dim] <= _pt[dim] <= max[dim]. A rectangle may be empty, in the
38 * sense of having zero area, but it will always contain at least one
39 * point. Infinities are also permitted.
40 */
41 class Rect {
42 public:
43 Rect() : _min(-_inf(), -_inf()), _max(_inf(), _inf()) {}
44 Rect(Point const &p0, Point const &p1);
45 Rect(NRRect *r);
46 Rect(NRRectL *r);
48 Point const &min() const { return _min; }
49 Point const &max() const { return _max; }
51 /** returns the four corners of the rectangle in order
52 * (clockwise if +Y is up, anticlockwise if +Y is down) */
53 Point corner(unsigned i) const;
55 /** returns a vector from min to max. */
56 Point dimensions() const;
58 /** returns the midpoint of this rect. */
59 Point midpoint() const;
61 bool isEmpty(double epsilon=1e-6) const {
62 return isEmpty<X>(epsilon) || isEmpty<Y>(epsilon);
63 }
65 bool intersects(Rect const &r) const {
66 return intersects<X>(r) && intersects<Y>(r);
67 }
68 bool contains(Rect const &r) const {
69 return contains<X>(r) && contains<Y>(r);
70 }
71 bool contains(Point const &p) const {
72 return contains<X>(p) && contains<Y>(p);
73 }
75 double area() const {
76 return extent<X>() * extent<Y>();
77 }
79 double maxExtent() const {
80 return MAX(extent<X>(), extent<Y>());
81 }
83 double extent(Dim2 const axis) const {
84 switch (axis) {
85 case X: return extent<X>();
86 case Y: return extent<Y>();
87 default: g_error("invalid axis value %d", (int) axis); return 0;
88 };
89 }
91 double extent(unsigned i) const throw(std::out_of_range) {
92 switch (i) {
93 case 0: return extent<X>();
94 case 1: return extent<Y>();
95 default: throw std::out_of_range("Dimension out of range");
96 };
97 }
99 /**
100 \brief Remove some precision from the Rect
101 \param places The number of decimal places left in the end
103 This function just calls round on the \c _min and \c _max points.
104 */
105 inline void round(int places = 0) {
106 _min.round(places);
107 _max.round(places);
108 return;
109 }
111 /** Translates the rectangle by p. */
112 void offset(Point p);
114 /** Makes this rectangle large enough to include the point p. */
115 void expandTo(Point p);
117 /** Makes this rectangle large enough to include the rectangle r. */
118 void expandTo(Rect const &r);
120 inline void move_left (gdouble by) {
121 _min[NR::X] += by;
122 }
123 inline void move_right (gdouble by) {
124 _max[NR::X] += by;
125 }
126 inline void move_top (gdouble by) {
127 _min[NR::Y] += by;
128 }
129 inline void move_bottom (gdouble by) {
130 _max[NR::Y] += by;
131 }
133 void growBy (gdouble by);
135 /** Scales the rect by s, with origin at 0, 0 */
136 inline Rect operator*(double const s) const {
137 return Rect(s * min(), s * max());
138 }
140 /** Transforms the rect by m. Note that it gives correct results only for scales and translates */
141 inline Rect operator*(Matrix const m) const {
142 return Rect(_min * m, _max * m);
143 }
145 inline bool operator==(Rect const &in_rect) {
146 return ((this->min() == in_rect.min()) && (this->max() == in_rect.max()));
147 }
149 friend inline std::ostream &operator<<(std::ostream &out_file, NR::Rect const &in_rect);
151 private:
152 Rect(Nothing) : _min(1, 1), _max(-1, -1) {}
154 static double _inf() {
155 return std::numeric_limits<double>::infinity();
156 }
158 template <NR::Dim2 axis>
159 double extent() const {
160 return _max[axis] - _min[axis];
161 }
163 template <NR::Dim2 axis>
164 bool isEmpty(double epsilon) const {
165 return extent<axis>() < epsilon;
166 }
168 template <Dim2 axis>
169 bool intersects(Rect const &r) const {
170 return _max[axis] >= r._min[axis] && _min[axis] <= r._max[axis];
171 }
173 template <Dim2 axis>
174 bool contains(Rect const &r) const {
175 return contains(r._min) && contains(r._max);
176 }
178 template <Dim2 axis>
179 bool contains(Point const &p) const {
180 return p[axis] >= _min[axis] && p[axis] <= _max[axis];
181 }
183 Point _min, _max;
185 friend class MaybeStorage<Rect>;
186 friend Maybe<Rect> intersection(Maybe<Rect> const &, Maybe<Rect> const &);
187 friend Rect union_bounds(Rect const &, Rect const &);
188 };
190 template <>
191 class MaybeStorage<Rect> {
192 public:
193 MaybeStorage() : _rect(Nothing()) {}
194 MaybeStorage(Rect const &rect) : _rect(rect) {}
196 bool is_nothing() const {
197 return _rect._min[X] > _rect._max[X];
198 }
199 Rect const &value() const { return _rect; }
200 Rect &value() { return _rect; }
202 private:
203 Rect _rect;
204 };
206 /** Returns the set of points shared by both rectangles. */
207 Maybe<Rect> intersection(Maybe<Rect> const & a, Maybe<Rect> const & b);
209 /** Returns the smallest rectangle that encloses both rectangles. */
210 Rect union_bounds(Rect const &a, Rect const &b);
211 inline Rect union_bounds(Maybe<Rect> const & a, Rect const &b) {
212 if (a) {
213 return union_bounds(*a, b);
214 } else {
215 return b;
216 }
217 }
218 inline Rect union_bounds(Rect const &a, Maybe<Rect> const & b) {
219 if (b) {
220 return union_bounds(a, *b);
221 } else {
222 return a;
223 }
224 }
225 inline Maybe<Rect> union_bounds(Maybe<Rect> const & a, Maybe<Rect> const & b)
226 {
227 if (!a) {
228 return b;
229 } else if (!b) {
230 return a;
231 } else {
232 return union_bounds(*a, *b);
233 }
234 }
236 /** A function to print out the rectange if sent to an output
237 stream. */
238 inline std::ostream
239 &operator<<(std::ostream &out_file, NR::Rect const &in_rect)
240 {
241 out_file << "Rectangle:\n";
242 out_file << "\tMin Point -> " << in_rect.min() << "\n";
243 out_file << "\tMax Point -> " << in_rect.max() << "\n";
245 return out_file;
246 }
248 } /* namespace NR */
250 /* legacy rect stuff */
252 struct NRMatrix;
254 /* NULL rect is infinite */
256 struct NRRect {
257 NRRect() {}
258 NRRect(NR::Coord xmin, NR::Coord ymin, NR::Coord xmax, NR::Coord ymax)
259 : x0(xmin), y0(ymin), x1(xmin), y1(ymin)
260 {}
261 explicit NRRect(NR::Rect const &rect);
262 explicit NRRect(NR::Maybe<NR::Rect> const &rect);
263 operator NR::Maybe<NR::Rect>() const { return upgrade(); }
264 NR::Maybe<NR::Rect> upgrade() const;
266 NR::Coord x0, y0, x1, y1;
267 };
269 #define nr_rect_d_set_empty(r) (*(r) = NR_RECT_EMPTY)
270 #define nr_rect_l_set_empty(r) (*(r) = NR_RECT_L_EMPTY)
272 #define nr_rect_d_test_empty(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
273 #define nr_rect_l_test_empty(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
275 #define nr_rect_d_test_intersect(r0,r1) \
276 (!nr_rect_d_test_empty(r0) && !nr_rect_d_test_empty(r1) && \
277 !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
278 #define nr_rect_l_test_intersect(r0,r1) \
279 (!nr_rect_l_test_empty(r0) && !nr_rect_l_test_empty(r1) && \
280 !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
282 #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))))
283 #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))))
284 #define nr_rect_l_test_inside(r,x,y) ((!(r) || (!NR_RECT_DFLS_TEST_EMPTY(r) && NR_RECT_LS_TEST_INSIDE(r,x,y))))
286 // returns minimal rect which covers all of r0 not covered by r1
287 NRRectL *nr_rect_l_subtract(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
289 // returns the area of r
290 NR::ICoord nr_rect_l_area(NRRectL *r);
292 /* NULL values are OK for r0 and r1, but not for d */
293 NRRect *nr_rect_d_intersect(NRRect *d, NRRect const *r0, NRRect const *r1);
294 NRRectL *nr_rect_l_intersect(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
296 NRRect *nr_rect_d_union(NRRect *d, NRRect const *r0, NRRect const *r1);
297 NRRectL *nr_rect_l_union(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
299 NRRect *nr_rect_union_pt(NRRect *dst, NR::Point const &p);
300 NRRect *nr_rect_d_union_xy(NRRect *d, NR::Coord x, NR::Coord y);
301 NRRectL *nr_rect_l_union_xy(NRRectL *d, NR::ICoord x, NR::ICoord y);
303 NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NR::Matrix const &m);
304 NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NRMatrix const *m);
305 NRRectL *nr_rect_l_enlarge(NRRectL *d, int amount);
308 #endif /* !LIBNR_NR_RECT_H_SEEN */
310 /*
311 Local Variables:
312 mode:c++
313 c-file-style:"stroustrup"
314 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
315 indent-tabs-mode:nil
316 fill-column:99
317 End:
318 */
319 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :