4ae5642ae795015a614ba9ca1346f11386439d66
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 namespace NR {
29 struct Matrix;
31 /** A rectangle is always aligned to the X and Y axis. This means it
32 * can be defined using only 4 coordinates, and determining
33 * intersection is very efficient. The points inside a rectangle are
34 * min[dim] <= _pt[dim] <= max[dim]. Emptiness, however, is defined
35 * as having zero area, meaning an empty rectangle may still contain
36 * points. Infinities are also permitted. */
37 class Rect {
38 public:
39 Rect() : _min(-_inf(), -_inf()), _max(_inf(), _inf()) {}
40 Rect(Point const &p0, Point const &p1);
42 Point const &min() const { return _min; }
43 Point const &max() const { return _max; }
45 /** returns the four corners of the rectangle in order
46 * (clockwise if +Y is up, anticlockwise if +Y is down) */
47 Point corner(unsigned i) const;
49 /** returns a vector from min to max. */
50 Point dimensions() const;
52 /** returns the midpoint of this rect. */
53 Point midpoint() const;
55 /** does this rectangle have zero area? */
56 bool isEmpty() const {
57 return isEmpty<X>() || isEmpty<Y>();
58 }
60 bool intersects(Rect const &r) const {
61 return intersects<X>(r) && intersects<Y>(r);
62 }
63 bool contains(Rect const &r) const {
64 return contains<X>(r) && contains<Y>(r);
65 }
66 bool contains(Point const &p) const {
67 return contains<X>(p) && contains<Y>(p);
68 }
70 double area() const {
71 return extent<X>() * extent<Y>();
72 }
74 double maxExtent() const {
75 return MAX(extent<X>(), extent<Y>());
76 }
78 double extent(Dim2 const axis) const {
79 switch (axis) {
80 case X: return extent<X>();
81 case Y: return extent<Y>();
82 default: g_error("invalid axis value %d", (int) axis); return 0;
83 };
84 }
86 double extent(unsigned i) const throw(std::out_of_range) {
87 switch (i) {
88 case 0: return extent<X>();
89 case 1: return extent<Y>();
90 default: throw std::out_of_range("Dimension out of range");
91 };
92 }
94 /**
95 \brief Remove some precision from the Rect
96 \param places The number of decimal places left in the end
98 This function just calls round on the \c _min and \c _max points.
99 */
100 inline void round(int places = 0) {
101 _min.round(places);
102 _max.round(places);
103 return;
104 }
106 /** Translates the rectangle by p. */
107 void offset(Point p);
109 /** Makes this rectangle large enough to include the point p. */
110 void expandTo(Point p);
112 /** Makes this rectangle large enough to include the rectangle r. */
113 void expandTo(Rect const &r);
115 inline void move_left (gdouble by) {
116 _min[NR::X] += by;
117 }
118 inline void move_right (gdouble by) {
119 _max[NR::X] += by;
120 }
121 inline void move_top (gdouble by) {
122 _min[NR::Y] += by;
123 }
124 inline void move_bottom (gdouble by) {
125 _max[NR::Y] += by;
126 }
128 /** Scales the rect by s, with origin at 0, 0 */
129 inline Rect operator*(double const s) const {
130 return Rect(s * min(), s * max());
131 }
133 /** Transforms the rect by m. Note that it gives correct results only for scales and translates */
134 inline Rect operator*(Matrix const m) const {
135 return Rect(_min * m, _max * m);
136 }
138 inline bool operator==(Rect const &in_rect) {
139 return ((this->min() == in_rect.min()) && (this->max() == in_rect.max()));
140 }
142 friend inline std::ostream &operator<<(std::ostream &out_file, NR::Rect const &in_rect);
144 private:
145 Rect(Nothing) : _min(1, 1), _max(-1, -1) {}
147 static double _inf() {
148 return std::numeric_limits<double>::infinity();
149 }
151 template <NR::Dim2 axis>
152 double extent() const {
153 return _max[axis] - _min[axis];
154 }
156 template <Dim2 axis>
157 bool isEmpty() const {
158 return !( _min[axis] < _max[axis] );
159 }
161 template <Dim2 axis>
162 bool intersects(Rect const &r) const {
163 return _max[axis] >= r._min[axis] && _min[axis] <= r._max[axis];
164 }
166 template <Dim2 axis>
167 bool contains(Rect const &r) const {
168 return contains(r._min) && contains(r._max);
169 }
171 template <Dim2 axis>
172 bool contains(Point const &p) const {
173 return p[axis] >= _min[axis] && p[axis] <= _max[axis];
174 }
176 Point _min, _max;
178 friend class MaybeStorage<Rect>;
179 friend Maybe<Rect> intersection(Maybe<Rect const &>, Maybe<Rect const &>);
180 friend Rect union_bounds(Rect const &, Rect const &);
181 };
183 template <>
184 class MaybeStorage<Rect> {
185 public:
186 MaybeStorage() : _rect(Nothing()) {}
187 MaybeStorage(Rect const &rect) : _rect(rect) {}
189 bool is_nothing() const {
190 return _rect._min[X] > _rect._max[X];
191 }
192 Rect const &value() const { return _rect; }
193 Rect &value() { return _rect; }
195 private:
196 Rect _rect;
197 };
199 /** Returns the set of points shared by both rectangles. */
200 Maybe<Rect> intersection(Maybe<Rect const &> a, Maybe<Rect const &> b);
202 /** Returns the smallest rectangle that encloses both rectangles. */
203 Rect union_bounds(Rect const &a, Rect const &b);
204 inline Rect union_bounds(Maybe<Rect const &> a, Rect const &b) {
205 if (a) {
206 return union_bounds(*a, b);
207 } else {
208 return b;
209 }
210 }
211 inline Rect union_bounds(Rect const &a, Maybe<Rect const &> b) {
212 if (b) {
213 return union_bounds(a, *b);
214 } else {
215 return a;
216 }
217 }
218 inline Maybe<Rect> union_bounds(Maybe<Rect const &> a, Maybe<Rect const &> b)
219 {
220 if (!a) {
221 return b;
222 } else if (!b) {
223 return a;
224 } else {
225 return union_bounds(*a, *b);
226 }
227 }
229 /** A function to print out the rectange if sent to an output
230 stream. */
231 inline std::ostream
232 &operator<<(std::ostream &out_file, NR::Rect const &in_rect)
233 {
234 out_file << "Rectangle:\n";
235 out_file << "\tMin Point -> " << in_rect.min() << "\n";
236 out_file << "\tMax Point -> " << in_rect.max() << "\n";
238 return out_file;
239 }
241 } /* namespace NR */
243 /* legacy rect stuff */
245 struct NRMatrix;
247 /* NULL rect is infinite */
249 struct NRRect {
250 NRRect() {}
251 NRRect(NR::Coord xmin, NR::Coord ymin, NR::Coord xmax, NR::Coord ymax)
252 : x0(xmin), y0(ymin), x1(xmin), y1(ymin)
253 {}
254 explicit NRRect(NR::Rect const &rect);
255 explicit NRRect(NR::Maybe<NR::Rect> const &rect);
256 operator NR::Maybe<NR::Rect>() const { return upgrade(); }
257 NR::Maybe<NR::Rect> upgrade() const;
259 NR::Coord x0, y0, x1, y1;
260 };
262 #define nr_rect_d_set_empty(r) (*(r) = NR_RECT_EMPTY)
263 #define nr_rect_l_set_empty(r) (*(r) = NR_RECT_L_EMPTY)
265 #define nr_rect_d_test_empty(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
266 #define nr_rect_l_test_empty(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
268 #define nr_rect_d_test_intersect(r0,r1) \
269 (!nr_rect_d_test_empty(r0) && !nr_rect_d_test_empty(r1) && \
270 !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
271 #define nr_rect_l_test_intersect(r0,r1) \
272 (!nr_rect_l_test_empty(r0) && !nr_rect_l_test_empty(r1) && \
273 !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
275 #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))))
276 #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))))
277 #define nr_rect_l_test_inside(r,x,y) ((!(r) || (!NR_RECT_DFLS_TEST_EMPTY(r) && NR_RECT_LS_TEST_INSIDE(r,x,y))))
279 // returns minimal rect which covers all of r0 not covered by r1
280 NRRectL *nr_rect_l_subtract(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
282 // returns the area of r
283 NR::ICoord nr_rect_l_area(NRRectL *r);
285 /* NULL values are OK for r0 and r1, but not for d */
286 NRRect *nr_rect_d_intersect(NRRect *d, NRRect const *r0, NRRect const *r1);
287 NRRectL *nr_rect_l_intersect(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
289 NRRect *nr_rect_d_union(NRRect *d, NRRect const *r0, NRRect const *r1);
290 NRRectL *nr_rect_l_union(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
292 NRRect *nr_rect_union_pt(NRRect *dst, NR::Point const &p);
293 NRRect *nr_rect_d_union_xy(NRRect *d, NR::Coord x, NR::Coord y);
294 NRRectL *nr_rect_l_union_xy(NRRectL *d, NR::ICoord x, NR::ICoord y);
296 NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NR::Matrix const &m);
297 NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NRMatrix const *m);
298 NRRectL *nr_rect_l_enlarge(NRRectL *d, int amount);
301 #endif /* !LIBNR_NR_RECT_H_SEEN */
303 /*
304 Local Variables:
305 mode:c++
306 c-file-style:"stroustrup"
307 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
308 indent-tabs-mode:nil
309 fill-column:99
310 End:
311 */
312 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :