1 /*
2  * Copyright (C) 2016 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 #pragma once
18 
19 #include <algorithm>
20 #include <cmath>
21 
22 namespace android {
23 
24 template<typename T>
saturate(T v)25 static constexpr T saturate(T v) noexcept {
26     return T(std::min(T(1), std::max(T(0), v)));
27 }
28 
29 template<typename T>
clamp(T v,T min,T max)30 static constexpr T clamp(T v, T min, T max) noexcept {
31     return T(std::min(max, std::max(min, v)));
32 }
33 
34 template<typename T>
mix(T x,T y,T a)35 static constexpr T mix(T x, T y, T a) noexcept {
36     return x * (T(1) - a) + y * a;
37 }
38 
39 template<typename T>
lerp(T x,T y,T a)40 static constexpr T lerp(T x, T y, T a) noexcept {
41     return mix(x, y, a);
42 }
43 
44 } // namespace std
45