Fawkes API Fawkes Development Version
common.h
1
2/***************************************************************************
3 * common.h - common math helper functions
4 *
5 * Created: Wed Oct 16 21:03:26 2013
6 * Copyright 2013 Bahram Maleki-Fard
7 *
8 ****************************************************************************/
9
10/* This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version. A runtime exception applies to
14 * this software (see LICENSE.GPL_WRE file mentioned below for details).
15 *
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU Library General Public License for more details.
20 *
21 * Read the full text in the LICENSE.GPL_WRE file in the doc directory.
22 */
23
24#ifndef _UTILS_MATH_COMMON_H_
25#define _UTILS_MATH_COMMON_H_
26
27#include <cmath>
28#include <limits>
29
30namespace fawkes {
31
32/** Fast square multiplication.
33 * @param x
34 * @return x^2
35 */
36inline double
37sqr(double x)
38{
39 return (x * x);
40}
41
42/** Fast square multiplication.
43 * @param x
44 * @return x^2
45 */
46inline float
47sqr(float x)
48{
49 return (x * x);
50}
51
52/** Fast square multiplication.
53 * @param x
54 * @return x^2
55 */
56inline int
57sqr(int x)
58{
59 return (x * x);
60}
61
62/** Fast square multiplication.
63 * @param x
64 * @return x^2
65 */
66inline unsigned long
67sqr(unsigned long x)
68{
69 return (x * x);
70}
71
72/** Get distance of two points.
73 * This is particularly useful if not using a more powerful
74 * representation like Eigen.
75 * @param x1 x coordinate of first point
76 * @param y1 y coordinate of first point
77 * @param x2 x coordinate of second point
78 * @param y2 y coordinate of second point
79 * @return distance
80 */
81inline float
82point_dist(float x1, float y1, float x2, float y2)
83{
84 return sqrtf(powf(x1 - x2, 2) + powf(y1 - y2, 2));
85}
86
87/** Check if two points are different with regard to a given threshold.
88 * This is particularly useful if not using a more powerful
89 * representation like Eigen.
90 * @param x1 x coordinate of first point
91 * @param y1 y coordinate of first point
92 * @param x2 x coordinate of second point
93 * @param y2 y coordinate of second point
94 * @param threshold the threshold to compare the distance between the
95 * points to.
96 * @return true if the distance of the two points is greater than or equal
97 * to the given threshold, false otherwise.
98 */
99inline bool
100points_different(float x1, float y1, float x2, float y2, float threshold = 1e-4)
101{
102 return sqrtf(powf(x1 - x2, 2) + powf(y1 - y2, 2)) >= threshold;
103}
104
105} // end namespace fawkes
106
107#endif
Fawkes library namespace.
float point_dist(float x1, float y1, float x2, float y2)
Get distance of two points.
Definition: common.h:82
double sqr(double x)
Fast square multiplication.
Definition: common.h:37
bool points_different(float x1, float y1, float x2, float y2, float threshold=1e-4)
Check if two points are different with regard to a given threshold.
Definition: common.h:100