1 /* Copyright (C) 2013-2016, The Regents of The University of Michigan.
2 All rights reserved.
3 This software was developed in the APRIL Robotics Lab under the
4 direction of Edwin Olson, ebolson@umich.edu. This software may be
5 available under alternative licensing terms; contact the address above.
6 Redistribution and use in source and binary forms, with or without
7 modification, are permitted provided that the following conditions are met:
8 1. Redistributions of source code must retain the above copyright notice, this
9    list of conditions and the following disclaimer.
10 2. Redistributions in binary form must reproduce the above copyright notice,
11    this list of conditions and the following disclaimer in the documentation
12    and/or other materials provided with the distribution.
13 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
14 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
17 ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
20 ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 The views and conclusions contained in the software and documentation are those
24 of the authors and should not be interpreted as representing official policies,
25 either expressed or implied, of the Regents of The University of Michigan.
26 */
27 
28 #pragma once
29 
30 #include <math.h>
31 #include <float.h>
32 #include <stdlib.h>
33 #include <stdint.h>
34 #include <assert.h>
35 #include <string.h> // memcpy
36 
37 #ifdef __cplusplus
38 //extern "C" {
39 #endif
40 
41 #ifndef M_TWOPI
42 # define M_TWOPI       6.2831853071795862319959  /* 2*pi */
43 #endif
44 
45 #ifndef M_PI
46 # define M_PI 3.141592653589793238462643383279502884196
47 #endif
48 
49 #define to_radians(x) ( (x) * (M_PI / 180.0 ))
50 #define to_degrees(x) ( (x) * (180.0 / M_PI ))
51 
52 #ifndef max
53 #define max(A, B) (A < B ? B : A)
54 #endif
55 #ifndef min
56 #define min(A, B) (A < B ? A : B)
57 #endif
58 
59   /* DEPRECATE, threshold meaningless without context.
60 static inline int dequals(double a, double b)
61 {
62     double thresh = 1e-9;
63     return (fabs(a-b) < thresh);
64 }
65   */
66 
dequals_mag(double a,double b,double thresh)67 static inline int dequals_mag(double a, double b, double thresh)
68 {
69     return (fabs(a-b) < thresh);
70 }
71 
isq(int v)72 static inline int isq(int v)
73 {
74     return v*v;
75 }
76 
fsq(float v)77 static inline float fsq(float v)
78 {
79     return v*v;
80 }
81 
sq(double v)82 static inline double sq(double v)
83 {
84     return v*v;
85 }
86 
sgn(double v)87 static inline double sgn(double v)
88 {
89     return (v>=0) ? 1 : -1;
90 }
91 
92 // random number between [0, 1)
randf()93 static inline float randf()
94 {
95     return (float)(rand() / (static_cast<float>(RAND_MAX) + 1.0f));
96 }
97 
98 
signed_randf()99 static inline float signed_randf()
100 {
101     return randf()*2 - 1;
102 }
103 
104 // return a random integer between [0, bound)
irand(int bound)105 static inline int irand(int bound)
106 {
107     int v = (int) (randf()*bound);
108     if (v == bound)
109         return (bound-1);
110     //assert(v >= 0);
111     //assert(v < bound);
112     return v;
113 }
114 
115 /** Map vin to [0, 2*PI) **/
mod2pi_positive(double vin)116 static inline double mod2pi_positive(double vin)
117 {
118     return vin - M_TWOPI * floor(vin / M_TWOPI);
119 }
120 
121 /** Map vin to [-PI, PI) **/
mod2pi(double vin)122 static inline double mod2pi(double vin)
123 {
124     return mod2pi_positive(vin + M_PI) - M_PI;
125 }
126 
127 /** Return vin such that it is within PI degrees of ref **/
mod2pi_ref(double ref,double vin)128 static inline double mod2pi_ref(double ref, double vin)
129 {
130     return ref + mod2pi(vin - ref);
131 }
132 
133 /** Map vin to [0, 360) **/
mod360_positive(double vin)134 static inline double mod360_positive(double vin)
135 {
136     return vin - 360 * floor(vin / 360);
137 }
138 
139 /** Map vin to [-180, 180) **/
mod360(double vin)140 static inline double mod360(double vin)
141 {
142     return mod360_positive(vin + 180) - 180;
143 }
144 
mod_positive(int vin,int mod)145 static inline int mod_positive(int vin, int mod) {
146     return (vin % mod + mod) % mod;
147 }
148 
theta_to_int(double theta,int max)149 static inline int theta_to_int(double theta, int max)
150 {
151     theta = mod2pi_ref(M_PI, theta);
152     int v = (int) (theta / M_TWOPI * max);
153 
154     if (v == max)
155         v = 0;
156 
157     assert (v >= 0 && v < max);
158 
159     return v;
160 }
161 
imin(int a,int b)162 static inline int imin(int a, int b)
163 {
164     return (a < b) ? a : b;
165 }
166 
imax(int a,int b)167 static inline int imax(int a, int b)
168 {
169     return (a > b) ? a : b;
170 }
171 
imin64(int64_t a,int64_t b)172 static inline int64_t imin64(int64_t a, int64_t b)
173 {
174     return (a < b) ? a : b;
175 }
176 
imax64(int64_t a,int64_t b)177 static inline int64_t imax64(int64_t a, int64_t b)
178 {
179     return (a > b) ? a : b;
180 }
181 
iclamp(int v,int minv,int maxv)182 static inline int iclamp(int v, int minv, int maxv)
183 {
184     return imax(minv, imin(v, maxv));
185 }
186 
dclamp(double a,double min,double max)187 static inline double dclamp(double a, double min, double max)
188 {
189     if (a < min)
190         return min;
191     if (a > max)
192         return max;
193     return a;
194 }
195 
fltcmp(float f1,float f2)196 static inline int fltcmp (float f1, float f2)
197 {
198     float epsilon = f1-f2;
199     if (epsilon < 0.0)
200         return -1;
201     else if (epsilon > 0.0)
202         return  1;
203     else
204         return  0;
205 }
206 
dblcmp(double d1,double d2)207 static inline int dblcmp (double d1, double d2)
208 {
209     double epsilon = d1-d2;
210     if (epsilon < 0.0)
211         return -1;
212     else if (epsilon > 0.0)
213         return  1;
214     else
215         return  0;
216 }
217 
double_pos_inf()218 static inline double double_pos_inf() {
219     //https://developer.arm.com/docs/dui0475/g/floating-point-support/sample-double-precision-floating-point-values-for-ieee-754-arithmetic
220     union {double d; int64_t i;} u;
221     u.i = 0x7FF0000000000000;
222     return u.d;
223 }
224 
double_neg_inf()225 static inline double double_neg_inf() {
226     //https://developer.arm.com/docs/dui0475/g/floating-point-support/sample-double-precision-floating-point-values-for-ieee-754-arithmetic
227     union {double d; uint64_t i;} u;
228     u.i = 0xFFF0000000000000;
229     return u.d;
230 }
231 
float_pos_inf()232 static inline float float_pos_inf() {
233     //https://developer.arm.com/docs/dui0475/g/floating-point-support/sample-single-precision-floating-point-values-for-ieee-754-arithmetic
234     union {float f; int32_t i;} u;
235     u.i = 0x7F800000;
236     return u.f;
237 }
238 
float_neg_inf()239 static inline float float_neg_inf() {
240     //https://developer.arm.com/docs/dui0475/g/floating-point-support/sample-single-precision-floating-point-values-for-ieee-754-arithmetic
241     union {float f; uint32_t i;} u;
242     u.i = 0xFF800000;
243     return u.f;
244 }
245 
246 #ifdef __cplusplus
247 //}
248 #endif
249