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BezierCurveT.cc
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49 
50 
51 
52 //=============================================================================
53 //
54 // CLASS BezierCurve - IMPLEMENTATION
55 //
56 //=============================================================================
57 
58 #define ACG_BEZIERCURVE_C
59 
60 //== INCLUDES =================================================================
61 
62 
63 #include "BezierCurveT.hh"
64 
65 
66 //== IMPLEMENTATION ==========================================================
67 
68 
69 namespace ACG {
70 
71 
72 //-----------------------------------------------------------------------------
73 
74 
75 template <class Point>
76 Point
78 operator()(Scalar _t) const
79 {
80  // copy controll points
81  std::vector<Point> b(*this);
82 
83  unsigned int n = b.size()-1, k;
84  Scalar t0(1.0-_t), t1(_t);
85 
86 
87  // de Casteljau
88  unsigned int i, j;
89  for (i=0; i<n; ++i)
90  for (j=0, k=n-i; j<k; ++j)
91  b[j] = t0*b[j] + t1*b[j+1];
92 
93 
94  return b[0];
95 }
96 
97 
98 //-----------------------------------------------------------------------------
99 
100 
101 template <class Point>
102 void
104 subdivide(Scalar _t, Self& _curve0, Self& _curve1) const
105 {
106  // copy controll points
107  std::vector<Point> b(*this);
108 
109  int n = degree();
110  Scalar t0(1.0-_t), t1(_t);
111 
112 
113  _curve0.clear();
114  _curve0.reserve(n+1);
115  _curve1.clear();
116  _curve1.reserve(n+1);
117 
118  std::vector<Point> tmp;
119  tmp.reserve(n+1);
120 
121 
122  // de Casteljau
123  int i, j, k;
124  for (i=0; i<n; ++i)
125  {
126  _curve0.push_back(b[0]);
127  tmp.push_back(b[n-i]);
128 
129  for (j=0, k=n-i; j<k; ++j)
130  b[j] = t0*b[j] + t1*b[j+1];
131  }
132 
133  _curve0.push_back(b[0]);
134  tmp.push_back(b[0]);
135 
136 
137  for (i=n; i>=0; --i)
138  _curve1.push_back(tmp[i]);
139 
140 
141  assert(_curve0.degree() == n);
142  assert(_curve1.degree() == n);
143 }
144 
145 
146 //=============================================================================
147 } // namespace ACG
148 //=============================================================================
unsigned int degree() const
return degree (= size()-1)
Point operator()(Scalar _t) const
evaluate curve at parameter _t using deCasteljau
Definition: BezierCurveT.cc:78
Namespace providing different geometric functions concerning angles.
Definition: DBSCANT.cc:51
void subdivide(Scalar _t, Self &_curve0, Self &_curve1) const