ab78c1651c53372eb9005d55520ba323c5929c58
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>
19 #include "libnr/nr-values.h"
20 #include <libnr/nr-coord.h>
21 #include <libnr/nr-i-coord.h>
22 #include <libnr/nr-dim2.h>
23 #include <libnr/nr-point.h>
24 #include <libnr/nr-maybe.h>
25 #include <libnr/nr-point-matrix-ops.h>
27 struct NRMatrix;
28 namespace NR {
29 struct Matrix;
30 }
32 /* NULL rect is infinite */
34 struct NRRect {
35 NR::Coord x0, y0, x1, y1;
36 };
38 inline bool empty(NRRect const &r)
39 {
40 return ( ( r.x0 > r.x1 ) ||
41 ( r.y0 > r.y1 ) );
42 }
44 #define nr_rect_d_set_empty(r) (*(r) = NR_RECT_EMPTY)
45 #define nr_rect_l_set_empty(r) (*(r) = NR_RECT_L_EMPTY)
47 #define nr_rect_d_test_empty(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
48 #define nr_rect_l_test_empty(r) ((r) && NR_RECT_DFLS_TEST_EMPTY(r))
50 #define nr_rect_d_test_intersect(r0,r1) \
51 (!nr_rect_d_test_empty(r0) && !nr_rect_d_test_empty(r1) && \
52 !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
53 #define nr_rect_l_test_intersect(r0,r1) \
54 (!nr_rect_l_test_empty(r0) && !nr_rect_l_test_empty(r1) && \
55 !((r0) && (r1) && !NR_RECT_DFLS_TEST_INTERSECT(r0, r1)))
57 #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))))
59 /* NULL values are OK for r0 and r1, but not for d */
60 NRRect *nr_rect_d_intersect(NRRect *d, NRRect const *r0, NRRect const *r1);
61 NRRectL *nr_rect_l_intersect(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
63 NRRect *nr_rect_d_union(NRRect *d, NRRect const *r0, NRRect const *r1);
64 NRRectL *nr_rect_l_union(NRRectL *d, NRRectL const *r0, NRRectL const *r1);
66 NRRect *nr_rect_union_pt(NRRect *dst, NR::Point const &p);
67 NRRect *nr_rect_d_union_xy(NRRect *d, NR::Coord x, NR::Coord y);
68 NRRectL *nr_rect_l_union_xy(NRRectL *d, NR::ICoord x, NR::ICoord y);
70 NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NR::Matrix const &m);
71 NRRect *nr_rect_d_matrix_transform(NRRect *d, NRRect const *s, NRMatrix const *m);
72 NRRectL *nr_rect_l_enlarge(NRRectL *d, int amount);
74 namespace NR {
76 /** A rectangle is always aligned to the X and Y axis. This means it
77 * can be defined using only 4 coordinates, and determining
78 * intersection is very efficient. The points inside a rectangle are
79 * min[dim] <= _pt[dim] <= max[dim]. Emptiness, however, is defined
80 * as having zero area, meaning an empty rectangle may still contain
81 * points. Infinities are also permitted. */
82 class Rect {
83 public:
84 Rect() : _min(0.0, 0.0), _max(0.0, 0.0) {}
85 Rect(NRRect const &r) : _min(r.x0, r.y0), _max(r.x1, r.y1) {}
86 Rect(Rect const &r) : _min(r._min), _max(r._max) {}
87 Rect(Point const &p0, Point const &p1);
89 Point const &min() const { return _min; }
90 Point const &max() const { return _max; }
92 /** returns the four corners of the rectangle in order
93 * (clockwise if +Y is up, anticlockwise if +Y is down) */
94 Point corner(unsigned i) const;
96 /** returns a vector from min to max. */
97 Point dimensions() const;
99 /** returns the midpoint of this rect. */
100 Point midpoint() const;
102 /** does this rectangle have zero area? */
103 bool isEmpty() const {
104 return isEmpty<X>() || isEmpty<Y>();
105 }
107 bool intersects(Rect const &r) const {
108 return intersects<X>(r) && intersects<Y>(r);
109 }
110 bool contains(Rect const &r) const {
111 return contains<X>(r) && contains<Y>(r);
112 }
113 bool contains(Point const &p) const {
114 return contains<X>(p) && contains<Y>(p);
115 }
117 double area() const {
118 return extent<X>() * extent<Y>();
119 }
121 double maxExtent() const {
122 return MAX(extent<X>(), extent<Y>());
123 }
125 double extent(Dim2 const axis) const {
126 switch (axis) {
127 case X: return extent<X>();
128 case Y: return extent<Y>();
129 default: g_error("invalid axis value %d", (int) axis); return 0;
130 };
131 }
133 double extent(unsigned i) const throw(std::out_of_range) {
134 switch (i) {
135 case 0: return extent<X>();
136 case 1: return extent<Y>();
137 default: throw std::out_of_range("Dimension out of range");
138 };
139 }
141 /**
142 \brief Remove some precision from the Rect
143 \param places The number of decimal places left in the end
145 This function just calls round on the \c _min and \c _max points.
146 */
147 inline void round(int places = 0) {
148 _min.round(places);
149 _max.round(places);
150 return;
151 }
153 /** Translates the rectangle by p. */
154 void offset(Point p);
156 /** Makes this rectangle large enough to include the point p. */
157 void expandTo(Point p);
159 /** Makes this rectangle large enough to include the rectangle r. */
160 void expandTo(Rect const &r);
162 inline void move_left (gdouble by) {
163 _min[NR::X] += by;
164 }
165 inline void move_right (gdouble by) {
166 _max[NR::X] += by;
167 }
168 inline void move_top (gdouble by) {
169 _min[NR::Y] += by;
170 }
171 inline void move_bottom (gdouble by) {
172 _max[NR::Y] += by;
173 }
175 /** Returns the set of points shared by both rectangles. */
176 static Maybe<Rect> intersection(Rect const &a, Rect const &b);
178 /** Returns the smallest rectangle that encloses both rectangles. */
179 static Rect union_bounds(Rect const &a, Rect const &b);
181 /** Scales the rect by s, with origin at 0, 0 */
182 inline Rect operator*(double const s) const {
183 return Rect(s * min(), s * max());
184 }
186 /** Transforms the rect by m. Note that it gives correct results only for scales and translates */
187 inline Rect operator*(Matrix const m) const {
188 return Rect(_min * m, _max * m);
189 }
191 inline bool operator==(Rect const &in_rect) {
192 return ((this->min() == in_rect.min()) && (this->max() == in_rect.max()));
193 }
195 friend inline std::ostream &operator<<(std::ostream &out_file, NR::Rect const &in_rect);
197 private:
199 template <NR::Dim2 axis>
200 double extent() const {
201 return _max[axis] - _min[axis];
202 }
204 template <Dim2 axis>
205 bool isEmpty() const {
206 return !( _min[axis] < _max[axis] );
207 }
209 template <Dim2 axis>
210 bool intersects(Rect const &r) const {
211 return _max[axis] >= r._min[axis] && _min[axis] <= r._max[axis];
212 }
214 template <Dim2 axis>
215 bool contains(Rect const &r) const {
216 return contains(r._min) && contains(r._max);
217 }
219 template <Dim2 axis>
220 bool contains(Point const &p) const {
221 return p[axis] >= _min[axis] && p[axis] <= _max[axis];
222 }
224 Point _min, _max;
226 /* evil, but temporary */
227 friend class Maybe<Rect>;
228 };
230 /** A function to print out the rectange if sent to an output
231 stream. */
232 inline std::ostream
233 &operator<<(std::ostream &out_file, NR::Rect const &in_rect)
234 {
235 out_file << "Rectangle:\n";
236 out_file << "\tMin Point -> " << in_rect.min() << "\n";
237 out_file << "\tMax Point -> " << in_rect.max() << "\n";
239 return out_file;
240 }
242 } /* namespace NR */
245 #endif /* !LIBNR_NR_RECT_H_SEEN */
247 /*
248 Local Variables:
249 mode:c++
250 c-file-style:"stroustrup"
251 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
252 indent-tabs-mode:nil
253 fill-column:99
254 End:
255 */
256 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :