1 #ifndef SEEN_Geom_TRANSFORMS_H
2 #define SEEN_Geom_TRANSFORMS_H
3 
4 #include "matrix.h"
5 #include <cmath>
6 
7 #ifndef M_PI
8 #define M_PI 3.14159265359;
9 #endif
10 
11 namespace Geom {
12 
13 template <typename T>
14 struct TransformConcept {
15     T t;
16     Matrix m;
17     Point p;
constraintsTransformConcept18     void constraints() {
19         m = t;  //implicit conversion
20         t = t.inverse();
21         p = p * t;
22         t = t * t;
23     }
24 };
25 
26 
27 class Rotate;
28 class Translate {
29   private:
30     Translate();
31     Point vec;
32   public:
Translate(Point const & p)33     explicit Translate(Point const &p) : vec(p) {}
Translate(Coord const x,Coord const y)34     explicit Translate(Coord const x, Coord const y) : vec(x, y) {}
Matrix()35     inline operator Matrix() const { return Matrix(1, 0, 0, 1, vec[X], vec[Y]); }
36 
37     inline Coord operator[](Dim2 const dim) const { return vec[dim]; }
38     inline Coord operator[](unsigned const dim) const { return vec[dim]; }
39     inline bool operator==(Translate const &o) const { return vec == o.vec; }
40     inline bool operator!=(Translate const &o) const { return vec != o.vec; }
41 
inverse()42     inline Translate inverse() const { return Translate(-vec); }
43 
44     friend Point operator*(Point const &v, Translate const &t);
45     inline Translate operator*(Translate const &b) const { return Translate(vec + b.vec); }
46 
47     friend Matrix operator*(Translate const &t, Rotate const &r);
48 };
49 
50 inline Point operator*(Point const &v, Translate const &t) { return v + t.vec; }
51 
52 class Scale {
53   private:
54     Point vec;
55     Scale();
56   public:
Scale(Point const & p)57     explicit Scale(Point const &p) : vec(p) {}
Scale(Coord const x,Coord const y)58     Scale(Coord const x, Coord const y) : vec(x, y) {}
Scale(Coord const s)59     explicit Scale(Coord const s) : vec(s, s) {}
Matrix()60     inline operator Matrix() const { return Matrix(vec[X], 0, 0, vec[Y], 0, 0); }
61 
62     inline Coord operator[](Dim2 const d) const { return vec[d]; }
63     inline Coord operator[](unsigned const d) const { return vec[d]; }
64     //TODO: should we keep these mutators? add them to the other transforms?
65     inline Coord &operator[](Dim2 const d) { return vec[d]; }
66     inline Coord &operator[](unsigned const d) { return vec[d]; }
67     inline bool operator==(Scale const &o) const { return vec == o.vec; }
68     inline bool operator!=(Scale const &o) const { return vec != o.vec; }
69 
inverse()70     inline Scale inverse() const { return Scale(1./vec[0], 1./vec[1]); }
71 
72     friend Point operator*(Point const &v, Translate const &t);
73     inline Scale operator*(Scale const &b) const { return Scale(vec[X]*b[X], vec[Y]*b[Y]); }
74 };
75 
76 inline Point operator*(Point const &p, Scale const &s) { return Point(p[X] * s[X], p[Y] * s[Y]); }
77 
78 /** Notionally an Geom::Matrix corresponding to rotation about the origin.
79     Behaves like Geom::Matrix for multiplication.
80 **/
81 class Rotate {
82   private:
83     Rotate();
84     Point vec;
85   public:
Rotate(Coord theta)86     explicit Rotate(Coord theta) : vec(std::cos(theta), std::sin(theta)) {}
Rotate(Point const & p)87     Rotate(Point const &p) {Point v = p; v.normalize(); vec = v;} //TODO: UGLY!
Rotate(Coord x,Coord y)88     explicit Rotate(Coord x, Coord y) { Rotate(Point(x, y)); }
Matrix()89     inline operator Matrix() const { return Matrix(vec[X], vec[Y], vec[Y], -vec[X], 0, 0); }
90 
91     inline Coord operator[](Dim2 const dim) const { return vec[dim]; }
92     inline Coord operator[](unsigned const dim) const { return vec[dim]; }
93     inline bool operator==(Rotate const &o) const { return vec == o.vec; }
94     inline bool operator!=(Rotate const &o) const { return vec != o.vec; }
95 
inverse()96     Rotate inverse() const { return Rotate( Point(vec[X], -vec[Y]) ); }
from_degrees(Coord deg)97     static Rotate from_degrees(Coord deg) {
98         Coord rad = (deg / 180.0) * M_PI;
99         return Rotate(rad);
100     }
101 
102     friend Point operator*(Point const &v, Rotate const &r);
103     inline Rotate operator*(Rotate const &b) const { return Rotate(vec * b); }
104 };
105 
106 inline Point operator*(Point const &v, Rotate const &r) { return v ^ r.vec; }
107 
108 Matrix operator*(Translate const &t, Scale const &s);
109 Matrix operator*(Translate const &t, Rotate const &r);
110 
111 Matrix operator*(Scale const &s, Translate const &t);
112 Matrix operator*(Scale const &s, Matrix const &m);
113 
114 Matrix operator*(Matrix const &m, Translate const &t);
115 Matrix operator*(Matrix const &m, Scale const &s);
116 Matrix operator*(Matrix const &m, Rotate const &r);
117 Matrix operator*(Matrix const &m1, Matrix const &m2);
118 
119 //TODO: matrix to trans/scale/rotate
120 
121 } /* namespace Geom */
122 
123 
124 #endif /* !SEEN_Geom_TRANSFORMS_H */
125 
126 /*
127   Local Variables:
128   mode:c++
129   c-file-style:"stroustrup"
130   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
131   indent-tabs-mode:nil
132   fill-column:99
133   End:
134 */
135 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :
136