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
67
68
69
70
71
72
73
74
75
76
77
|
//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.3
// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
//----------------------------------------------------------------------------
// Contact: mcseem@antigrain.com
// mcseemagg@yahoo.com
// http://www.antigrain.com
//----------------------------------------------------------------------------
//
// class bspline
//
//----------------------------------------------------------------------------
#ifndef AGG_BSPLINE_INCLUDED
#define AGG_BSPLINE_INCLUDED
#include "agg_basics.h"
namespace agg
{
//----------------------------------------------------------------bspline
// A very simple class of Bi-cubic Spline interpolation.
// First call init(num, x[], y[]) where num - number of source points,
// x, y - arrays of X and Y values respectively. Here Y must be a function
// of X. It means that all the X-coordinates must be arranged in the ascending
// order.
// Then call get(x) that calculates a value Y for the respective X.
// The class supports extrapolation, i.e. you can call get(x) where x is
// outside the given with init() X-range. Extrapolation is a simple linear
// function.
//
// See Implementation agg_bspline.cpp
//------------------------------------------------------------------------
class bspline
{
public:
~bspline();
bspline();
bspline(int num);
bspline(int num, const double* x, const double* y);
void init(int num);
void add_point(double x, double y);
void prepare();
void init(int num, const double* x, const double* y);
double get(double x) const;
double get_stateful(double x) const;
private:
bspline(const bspline&);
const bspline& operator = (const bspline&);
static void bsearch(int n, const double *x, double x0, int *i);
double extrapolation_left(double x) const;
double extrapolation_right(double x) const;
double interpolation(double x, int i) const;
int m_max;
int m_num;
double* m_x;
double* m_y;
double* m_am;
mutable int m_last_idx;
};
}
#endif
|
