1 /** @file
2 * @brief Nearest time routines for D2<SBasis> and Piecewise<D2<SBasis>>
3 *//*
4 * Authors:
5 * Marco Cecchetti <mrcekets at gmail.com>
6 *
7 * Copyright 2007-2008 authors
8 *
9 * This library is free software; you can redistribute it and/or
10 * modify it either under the terms of the GNU Lesser General Public
11 * License version 2.1 as published by the Free Software Foundation
12 * (the "LGPL") or, at your option, under the terms of the Mozilla
13 * Public License Version 1.1 (the "MPL"). If you do not alter this
14 * notice, a recipient may use your version of this file under either
15 * the MPL or the LGPL.
16 *
17 * You should have received a copy of the LGPL along with this library
18 * in the file COPYING-LGPL-2.1; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 * You should have received a copy of the MPL along with this library
21 * in the file COPYING-MPL-1.1
22 *
23 * The contents of this file are subject to the Mozilla Public License
24 * Version 1.1 (the "License"); you may not use this file except in
25 * compliance with the License. You may obtain a copy of the License at
26 * http://www.mozilla.org/MPL/
27 *
28 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
29 * OF ANY KIND, either express or implied. See the LGPL or the MPL for
30 * the specific language governing rights and limitations.
31 */
32
33
34 #ifndef LIB2GEOM_SEEN_NEAREST_TIME_H
35 #define LIB2GEOM_SEEN_NEAREST_TIME_H
36
37
38 #include <vector>
39
40 #include <2geom/d2.h>
41 #include <2geom/piecewise.h>
42 #include <2geom/exception.h>
43 #include <2geom/bezier.h>
44
45
46 namespace Geom
47 {
48
49 /*
50 * Given a line L specified by a point A and direction vector v,
51 * return the point on L nearest to p. Note that the returned value
52 * is with respect to the _normalized_ direction of v!
53 */
nearest_time(Point const & p,Point const & A,Point const & v)54 inline double nearest_time(Point const &p, Point const &A, Point const &v)
55 {
56 Point d(p - A);
57 return d[0] * v[0] + d[1] * v[1];
58 }
59
60 Coord nearest_time(Point const &p, D2<Bezier> const &bez, Coord from = 0, Coord to = 1);
61
62 ////////////////////////////////////////////////////////////////////////////////
63 // D2<SBasis> versions
64
65 /*
66 * Return the parameter t of a nearest point on the portion of the curve "c",
67 * related to the interval [from, to], to the point "p".
68 * The needed curve derivative "deriv" is passed as parameter.
69 * The function return the first nearest point to "p" that is found.
70 */
71 double nearest_time(Point const &p,
72 D2<SBasis> const &c, D2<SBasis> const &deriv,
73 double from = 0, double to = 1);
74
75 inline
76 double nearest_time(Point const &p,
77 D2<SBasis> const &c,
78 double from = 0, double to = 1 )
79 {
80 return nearest_time(p, c, Geom::derivative(c), from, to);
81 }
82
83 /*
84 * Return the parameters t of all the nearest times on the portion of
85 * the curve "c", related to the interval [from, to], to the point "p".
86 * The needed curve derivative "dc" is passed as parameter.
87 */
88 std::vector<double>
89 all_nearest_times(Point const& p,
90 D2<SBasis> const& c, D2<SBasis> const& dc,
91 double from = 0, double to = 1 );
92
93 inline
94 std::vector<double>
95 all_nearest_times(Point const &p,
96 D2<SBasis> const &c,
97 double from = 0, double to = 1)
98 {
99 return all_nearest_times(p, c, Geom::derivative(c), from, to);
100 }
101
102
103 ////////////////////////////////////////////////////////////////////////////////
104 // Piecewise< D2<SBasis> > versions
105
106 double nearest_time(Point const &p,
107 Piecewise< D2<SBasis> > const &c,
108 double from, double to);
109
110 inline
nearest_time(Point const & p,Piecewise<D2<SBasis>> const & c)111 double nearest_time(Point const& p, Piecewise< D2<SBasis> > const &c)
112 {
113 return nearest_time(p, c, c.cuts[0], c.cuts[c.size()]);
114 }
115
116
117 std::vector<double>
118 all_nearest_times(Point const &p,
119 Piecewise< D2<SBasis> > const &c,
120 double from, double to);
121
122 inline
123 std::vector<double>
all_nearest_times(Point const & p,Piecewise<D2<SBasis>> const & c)124 all_nearest_times( Point const& p, Piecewise< D2<SBasis> > const& c )
125 {
126 return all_nearest_times(p, c, c.cuts[0], c.cuts[c.size()]);
127 }
128
129 } // end namespace Geom
130
131 #endif // LIB2GEOM_SEEN_NEAREST_TIME_H
132 /*
133 Local Variables:
134 mode:c++
135 c-file-style:"stroustrup"
136 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
137 indent-tabs-mode:nil
138 fill-column:99
139 End:
140 */
141 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
142