AUtils.h revision 19da73b940a2648f05628f430068af2c6d1c2951 
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 */
24template<class T>
25inline 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 */
34template<class T>
35inline 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
43template<class T>
44inline static T abs(const T &a) {
45    return a < 0 ? -a : a;
46}
47
48template<class T>
49inline static const T &min(const T &a, const T &b) {
50    return a < b ? a : b;
51}
52
53template<class T>
54inline 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 */
59template<class T>
60inline 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