Panda3D

eggNurbsCurve.I
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1 /**
2 * PANDA 3D SOFTWARE
3 * Copyright (c) Carnegie Mellon University. All rights reserved.
4 *
5 * All use of this software is subject to the terms of the revised BSD
6 * license. You should have received a copy of this license along
7 * with this source code in a file named "LICENSE."
8 *
9 * @file eggNurbsCurve.I
10 * @author drose
11 * @date 2000-02-15
12 */
13
14 /**
15 *
16 */
17 INLINE EggNurbsCurve::
18 EggNurbsCurve(const std::string &name) : EggCurve(name) {
19 _order = 0;
20 }
21
22 /**
23 *
24 */
25 INLINE EggNurbsCurve::
26 EggNurbsCurve(const EggNurbsCurve &copy) :
27 EggCurve(copy),
28 _knots(copy._knots),
29 _order(copy._order)
30 {
31 }
32
33 /**
34 *
35 */
36 INLINE EggNurbsCurve &EggNurbsCurve::
37 operator = (const EggNurbsCurve &copy) {
38 EggCurve::operator = (copy);
39 _knots = copy._knots;
40 _order = copy._order;
41 return *this;
42 }
43
44 /**
45 * Directly changes the order to the indicated value (which must be an integer
46 * in the range 1 <= order <= 4). If possible, it is preferable to use the
47 * setup() method instead of this method, since changing the order directly
48 * may result in an invalid curve.
49 */
50 INLINE void EggNurbsCurve::
51 set_order(int order) {
52 nassertv(order >= 1 && order <= 4);
53 _order = order;
54 }
55
56 /**
57 * Resets the value of the indicated knot as indicated. k must be in the
58 * range 0 <= k < get_num_knots(), and the value must be in the range
59 * get_knot(k - 1) <= value <= get_knot(k + 1).
60 */
61 INLINE void EggNurbsCurve::
62 set_knot(int k, double value) {
63 nassertv(k >= 0 && k < (int)_knots.size());
64 _knots[k] = value;
65 }
66
67 /**
68 * Returns the order of the curve. The order is the degree of the NURBS
69 * equation plus 1; for a typical NURBS, the order is 4. With this
70 * implementation of NURBS, the order must be in the range [1, 4].
71 */
72 INLINE int EggNurbsCurve::
73 get_order() const {
74 return _order;
75 }
76
77 /**
78 * Returns the degree of the curve. For a typical NURBS, the degree is 3.
79 */
80 INLINE int EggNurbsCurve::
81 get_degree() const {
82 return _order - 1;
83 }
84
85 /**
86 * Returns the number of knots.
87 */
88 INLINE int EggNurbsCurve::
89 get_num_knots() const {
90 return _knots.size();
91 }
92
93 /**
94 * Returns the total number of control vertices that *should* be defined for
95 * the curve. This is determined by the number of knots and the order, in
96 * each direction; it does not necessarily reflect the number of vertices that
97 * have actually been added to the curve. (However, if the number of vertices
98 * in the curve are wrong, the curve is invalid.)
99 */
100 INLINE int EggNurbsCurve::
101 get_num_cvs() const {
102 return get_num_knots() - get_order();
103 }
104
105 /**
106 * Returns the nth knot value defined.
107 */
108 INLINE double EggNurbsCurve::
109 get_knot(int k) const {
110 nassertr(k >= 0 && k < (int)_knots.size(), 0.0);
111 return _knots[k];
112 }
EggCurve
A parametric curve of some kind.
Definition: eggCurve.h:24
EggNurbsCurve
A parametric NURBS curve.
Definition: eggNurbsCurve.h:26
EggNurbsCurve::get_degree
get_degree
Returns the degree of the curve.
Definition: eggNurbsCurve.h:56
EggNurbsCurve::get_order
get_order
Returns the order of the curve.
Definition: eggNurbsCurve.h:55
EggNurbsCurve::get_num_knots
get_num_knots
Returns the number of knots.
Definition: eggNurbsCurve.h:51
EggNurbsCurve::get_num_cvs
int get_num_cvs() const
Returns the total number of control vertices that *should* be defined for the curve.
Definition: eggNurbsCurve.I:101
EggNurbsCurve::set_knot
set_knot
Resets the value of the indicated knot as indicated.
Definition: eggNurbsCurve.h:58
EggNurbsCurve::set_order
set_order
Directly changes the order to the indicated value (which must be an integer in the range 1 <= order <...
Definition: eggNurbsCurve.h:55
EggNurbsCurve::get_knot
get_knot
Returns the nth knot value defined.
Definition: eggNurbsCurve.h:51