[2178] | 1 | /* -*- C++ -*- |
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| 2 | * |
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| 3 | * This file is a part of LEMON, a generic C++ optimization library |
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| 4 | * |
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| 5 | * Copyright (C) 2003-2006 |
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| 6 | * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport |
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| 7 | * (Egervary Research Group on Combinatorial Optimization, EGRES). |
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| 8 | * |
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| 9 | * Permission to use, modify and distribute this software is granted |
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| 10 | * provided that this copyright notice appears in all copies. For |
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| 11 | * precise terms see the accompanying LICENSE file. |
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| 12 | * |
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| 13 | * This software is provided "AS IS" with no warranty of any kind, |
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| 14 | * express or implied, and with no claim as to its suitability for any |
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| 15 | * purpose. |
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| 16 | * |
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| 17 | */ |
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| 18 | |
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| 19 | #ifndef LEMON_BEZIER_H |
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| 20 | #define LEMON_BEZIER_H |
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| 21 | |
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| 22 | ///\ingroup misc |
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| 23 | ///\file |
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| 24 | ///\brief Classes to compute with Bezier curves. |
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| 25 | /// |
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| 26 | ///Up to now this file is used internally by \ref graph_to_eps.h |
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| 27 | /// |
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| 28 | ///\author Alpar Juttner |
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| 29 | |
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| 30 | #include<lemon/xy.h> |
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| 31 | |
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| 32 | namespace lemon { |
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| 33 | |
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| 34 | class BezierBase { |
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| 35 | public: |
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| 36 | typedef xy<double> xy; |
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| 37 | protected: |
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| 38 | static xy conv(xy x,xy y,double t) {return (1-t)*x+t*y;} |
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| 39 | }; |
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| 40 | |
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| 41 | class Bezier1 : public BezierBase |
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| 42 | { |
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| 43 | public: |
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| 44 | xy p1,p2; |
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| 45 | |
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| 46 | Bezier1() {} |
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| 47 | Bezier1(xy _p1, xy _p2) :p1(_p1), p2(_p2) {} |
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| 48 | |
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| 49 | xy operator()(double t) const |
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| 50 | { |
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| 51 | // return conv(conv(p1,p2,t),conv(p2,p3,t),t); |
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| 52 | return conv(p1,p2,t); |
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| 53 | } |
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| 54 | Bezier1 before(double t) const |
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| 55 | { |
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| 56 | return Bezier1(p1,conv(p1,p2,t)); |
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| 57 | } |
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| 58 | |
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| 59 | Bezier1 after(double t) const |
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| 60 | { |
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| 61 | return Bezier1(conv(p1,p2,t),p2); |
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| 62 | } |
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| 63 | |
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| 64 | Bezier1 revert() const { return Bezier1(p2,p1);} |
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| 65 | Bezier1 operator()(double a,double b) const { return before(b).after(a/b); } |
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| 66 | xy grad() const { return p2-p1; } |
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| 67 | xy norm() const { return rot90(p2-p1); } |
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| 68 | xy grad(double) const { return grad(); } |
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| 69 | xy norm(double t) const { return rot90(grad(t)); } |
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| 70 | }; |
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| 71 | |
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| 72 | class Bezier2 : public BezierBase |
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| 73 | { |
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| 74 | public: |
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| 75 | xy p1,p2,p3; |
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| 76 | |
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| 77 | Bezier2() {} |
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| 78 | Bezier2(xy _p1, xy _p2, xy _p3) :p1(_p1), p2(_p2), p3(_p3) {} |
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| 79 | Bezier2(const Bezier1 &b) : p1(b.p1), p2(conv(b.p1,b.p2,.5)), p3(b.p2) {} |
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| 80 | xy operator()(double t) const |
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| 81 | { |
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| 82 | // return conv(conv(p1,p2,t),conv(p2,p3,t),t); |
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| 83 | return ((1-t)*(1-t))*p1+(2*(1-t)*t)*p2+(t*t)*p3; |
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| 84 | } |
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| 85 | Bezier2 before(double t) const |
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| 86 | { |
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| 87 | xy q(conv(p1,p2,t)); |
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| 88 | xy r(conv(p2,p3,t)); |
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| 89 | return Bezier2(p1,q,conv(q,r,t)); |
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| 90 | } |
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| 91 | |
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| 92 | Bezier2 after(double t) const |
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| 93 | { |
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| 94 | xy q(conv(p1,p2,t)); |
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| 95 | xy r(conv(p2,p3,t)); |
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| 96 | return Bezier2(conv(q,r,t),r,p3); |
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| 97 | } |
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| 98 | Bezier2 revert() const { return Bezier2(p3,p2,p1);} |
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| 99 | Bezier2 operator()(double a,double b) const { return before(b).after(a/b); } |
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| 100 | Bezier1 grad() const { return Bezier1(2.0*(p2-p1),2.0*(p3-p2)); } |
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| 101 | Bezier1 norm() const { return Bezier1(2.0*rot90(p2-p1),2.0*rot90(p3-p2)); } |
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| 102 | xy grad(double t) const { return grad()(t); } |
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| 103 | xy norm(double t) const { return rot90(grad(t)); } |
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| 104 | }; |
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| 105 | |
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| 106 | class Bezier3 : public BezierBase |
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| 107 | { |
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| 108 | public: |
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| 109 | xy p1,p2,p3,p4; |
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| 110 | |
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| 111 | Bezier3() {} |
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| 112 | Bezier3(xy _p1, xy _p2, xy _p3, xy _p4) :p1(_p1), p2(_p2), p3(_p3), p4(_p4) {} |
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| 113 | Bezier3(const Bezier1 &b) : p1(b.p1), p2(conv(b.p1,b.p2,1.0/3.0)), |
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| 114 | p3(conv(b.p1,b.p2,2.0/3.0)), p4(b.p2) {} |
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| 115 | Bezier3(const Bezier2 &b) : p1(b.p1), p2(conv(b.p1,b.p2,2.0/3.0)), |
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| 116 | p3(conv(b.p2,b.p3,1.0/3.0)), p4(b.p3) {} |
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| 117 | |
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| 118 | xy operator()(double t) const |
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| 119 | { |
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| 120 | // return Bezier2(conv(p1,p2,t),conv(p2,p3,t),conv(p3,p4,t))(t); |
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| 121 | return ((1-t)*(1-t)*(1-t))*p1+(3*t*(1-t)*(1-t))*p2+ |
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| 122 | (3*t*t*(1-t))*p3+(t*t*t)*p4; |
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| 123 | } |
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| 124 | Bezier3 before(double t) const |
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| 125 | { |
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| 126 | xy p(conv(p1,p2,t)); |
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| 127 | xy q(conv(p2,p3,t)); |
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| 128 | xy r(conv(p3,p4,t)); |
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| 129 | xy a(conv(p,q,t)); |
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| 130 | xy b(conv(q,r,t)); |
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| 131 | xy c(conv(a,b,t)); |
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| 132 | return Bezier3(p1,p,a,c); |
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| 133 | } |
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| 134 | |
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| 135 | Bezier3 after(double t) const |
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| 136 | { |
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| 137 | xy p(conv(p1,p2,t)); |
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| 138 | xy q(conv(p2,p3,t)); |
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| 139 | xy r(conv(p3,p4,t)); |
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| 140 | xy a(conv(p,q,t)); |
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| 141 | xy b(conv(q,r,t)); |
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| 142 | xy c(conv(a,b,t)); |
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| 143 | return Bezier3(c,b,r,p4); |
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| 144 | } |
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| 145 | Bezier3 revert() const { return Bezier3(p4,p3,p2,p1);} |
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| 146 | Bezier3 operator()(double a,double b) const { return before(b).after(a/b); } |
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| 147 | Bezier2 grad() const { return Bezier2(3.0*(p2-p1),3.0*(p3-p2),3.0*(p4-p3)); } |
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| 148 | Bezier2 norm() const { return Bezier2(3.0*rot90(p2-p1), |
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| 149 | 3.0*rot90(p3-p2), |
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| 150 | 3.0*rot90(p4-p3)); } |
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| 151 | xy grad(double t) const { return grad()(t); } |
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| 152 | xy norm(double t) const { return rot90(grad(t)); } |
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| 153 | |
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| 154 | template<class R,class F,class S,class D> |
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| 155 | R recSplit(F &_f,const S &_s,D _d) const |
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| 156 | { |
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| 157 | const xy a=(p1+p2)/2; |
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| 158 | const xy b=(p2+p3)/2; |
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| 159 | const xy c=(p3+p4)/2; |
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| 160 | const xy d=(a+b)/2; |
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| 161 | const xy e=(b+c)/2; |
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| 162 | const xy f=(d+e)/2; |
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| 163 | R f1=_f(Bezier3(p1,a,d,e),_d); |
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| 164 | R f2=_f(Bezier3(e,d,c,p4),_d); |
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| 165 | return _s(f1,f2); |
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| 166 | } |
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| 167 | |
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| 168 | }; |
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| 169 | |
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| 170 | } //END OF NAMESPACE LEMON |
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| 171 | |
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| 172 | #endif // LEMON_BEZIER_H |
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