LemonWriter and GraphWriter.
Little bit better documentation.
2 * src/lemon/bezier.h - Part of LEMON, a generic C++ optimization library
4 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport
5 * (Egervary Research Group on Combinatorial Optimization, EGRES).
7 * Permission to use, modify and distribute this software is granted
8 * provided that this copyright notice appears in all copies. For
9 * precise terms see the accompanying LICENSE file.
11 * This software is provided "AS IS" with no warranty of any kind,
12 * express or implied, and with no claim as to its suitability for any
17 #ifndef LEMON_BEZIER_H
18 #define LEMON_BEZIER_H
22 ///\brief Classes to compute with Bezier curves.
24 ///Up to now this file is used internally by \ref graph_to_eps.h
26 ///\author Alpar Juttner
34 typedef xy<double> xy;
36 static xy conv(xy x,xy y,double t) {return (1-t)*x+t*y;}
39 class Bezier1 : public BezierBase
45 Bezier1(xy _p1, xy _p2) :p1(_p1), p2(_p2) {}
47 xy operator()(double t) const
49 // return conv(conv(p1,p2,t),conv(p2,p3,t),t);
52 Bezier1 before(double t) const
54 return Bezier1(p1,conv(p1,p2,t));
57 Bezier1 after(double t) const
59 return Bezier1(conv(p1,p2,t),p2);
61 Bezier1 revert() { return Bezier1(p2,p1);}
62 Bezier1 operator()(double a,double b) { return before(b).after(a/b); }
63 xy grad() { return p2-p1; }
64 xy grad(double t) { return grad(); }
68 class Bezier2 : public BezierBase
74 Bezier2(xy _p1, xy _p2, xy _p3) :p1(_p1), p2(_p2), p3(_p3) {}
75 Bezier2(const Bezier1 &b) : p1(b.p1), p2(conv(b.p1,b.p2,.5)), p3(b.p2) {}
76 xy operator()(double t) const
78 // return conv(conv(p1,p2,t),conv(p2,p3,t),t);
79 return ((1-t)*(1-t))*p1+(2*(1-t)*t)*p2+(t*t)*p3;
81 Bezier2 before(double t) const
85 return Bezier2(p1,q,conv(q,r,t));
88 Bezier2 after(double t) const
92 return Bezier2(conv(q,r,t),r,p3);
94 Bezier2 revert() { return Bezier2(p3,p2,p1);}
95 Bezier2 operator()(double a,double b) { return before(b).after(a/b); }
96 Bezier1 grad() { return Bezier1(2.0*(p2-p1),2.0*(p3-p2)); }
97 xy grad(double t) { return grad()(t); }
100 class Bezier3 : public BezierBase
106 Bezier3(xy _p1, xy _p2, xy _p3, xy _p4) :p1(_p1), p2(_p2), p3(_p3), p4(_p4) {}
107 Bezier3(const Bezier1 &b) : p1(b.p1), p2(conv(b.p1,b.p2,1.0/3.0)),
108 p3(conv(b.p1,b.p2,2.0/3.0)), p4(b.p2) {}
109 Bezier3(const Bezier2 &b) : p1(b.p1), p2(conv(b.p1,b.p2,2.0/3.0)),
110 p3(conv(b.p2,b.p3,1.0/3.0)), p4(b.p3) {}
112 xy operator()(double t) const
114 // return Bezier2(conv(p1,p2,t),conv(p2,p3,t),conv(p3,p4,t))(t);
115 return ((1-t)*(1-t)*(1-t))*p1+(3*t*(1-t)*(1-t))*p2+
116 (3*t*t*(1-t))*p3+(t*t*t)*p4;
118 Bezier3 before(double t) const
126 return Bezier3(p1,p,a,c);
129 Bezier3 after(double t) const
137 return Bezier3(c,b,r,p4);
139 Bezier3 revert() { return Bezier3(p4,p3,p2,p1);}
140 Bezier3 operator()(double a,double b) { return before(b).after(a/b); }
141 Bezier2 grad() { return Bezier2(3.0*(p2-p1),3.0*(p3-p2),3.0*(p4-p3)); }
142 xy grad(double t) { return grad()(t); }
145 } //END OF NAMESPACE LEMON
147 #endif // LEMON_BEZIER_H