1 /*
2 * Copyright 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #ifndef A_UTILS_H_
18
19 #define A_UTILS_H_
20
21 /* ============================ math templates ============================ */
22
23 /* T must be integer type, den must not be 0 */
24 template<class T>
divRound(const T & nom,const T & den)25 inline static const T divRound(const T &nom, const T &den) {
26 if ((nom >= 0) ^ (den >= 0)) {
27 return (nom - den / 2) / den;
28 } else {
29 return (nom + den / 2) / den;
30 }
31 }
32
33 /* == ceil(nom / den). T must be integer type, den must not be 0 */
34 template<class T>
divUp(const T & nom,const T & den)35 inline static const T divUp(const T &nom, const T &den) {
36 if (den < 0) {
37 return (nom < 0 ? nom + den + 1 : nom) / den;
38 } else {
39 return (nom < 0 ? nom : nom + den - 1) / den;
40 }
41 }
42
43 template<class T>
abs(const T & a)44 inline static T abs(const T &a) {
45 return a < 0 ? -a : a;
46 }
47
48 template<class T>
min(const T & a,const T & b)49 inline static const T &min(const T &a, const T &b) {
50 return a < b ? a : b;
51 }
52
53 template<class T>
max(const T & a,const T & b)54 inline static const T &max(const T &a, const T &b) {
55 return a > b ? a : b;
56 }
57
58 /* T must be integer type, period must be positive */
59 template<class T>
periodicError(const T & val,const T & period)60 inline static T periodicError(const T &val, const T &period) {
61 T err = abs(val) % period;
62 return (err < (period / 2)) ? err : (period - err);
63 }
64
65 #endif // A_UTILS_H_
66