blob: 051372ce6cf0451a6f8d1354c08a22a4bf1cbe94 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
|
#ifndef SEEN_NR_ROTATE_H
#define SEEN_NR_ROTATE_H
/** \file
* Rotation about the origin.
*/
#include <libnr/nr-point.h>
#include <libnr/nr-point-fns.h>
#include <libnr/nr-point-ops.h>
namespace NR {
/** Notionally an NR::Matrix corresponding to rotation about the origin.
Behaves like NR::Matrix for multiplication.
**/
class rotate {
public:
Point vec;
private:
rotate();
public:
explicit rotate(Coord theta);
explicit rotate(Point const &p) : vec(p) {}
explicit rotate(Coord const x, Coord const y) : vec(x, y) {}
bool operator==(rotate const &o) const {
return vec == o.vec;
}
bool operator!=(rotate const &o) const {
return vec != o.vec;
}
inline rotate &operator*=(rotate const &b);
/* Defined in nr-rotate-ops.h. */
rotate inverse() const {
/** \todo
* In the usual case that vec is a unit vector (within rounding error),
* dividing by len_sq is either a noop or numerically harmful.
* Make a unit_rotate class (or the like) that knows its length is 1.
*/
double const len_sq = dot(vec, vec);
return rotate( Point(vec[X], -vec[Y])
/ len_sq );
}
};
} /* namespace NR */
#endif /* !SEEN_NR_ROTATE_H */
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
|
