1 /*
2  * Copyright (c) 2024 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef API_BASE_MATH_SPLINE_H
17 #define API_BASE_MATH_SPLINE_H
18 
19 #include <base/namespace.h>
20 
BASE_BEGIN_NAMESPACE()21 BASE_BEGIN_NAMESPACE()
22 namespace Math {
23 /** @ingroup group_math_spline */
24 /** For hermite interpolation */
25 template<typename T>
26 inline constexpr T Hermite(T const& v1, T const& t1, T const& v2, T const& t2, float s)
27 {
28     const float s2 = s * s;
29     const float s3 = s2 * s;
30     const float s23 = 2.f * s3;
31     const float s32 = 3.f * s2;
32 
33     const float f1 = s23 - s32 + 1.f;
34     const float f2 = -s23 + s32;
35     const float f3 = s3 - 2.f * s2 + s;
36     const float f4 = s3 - s2;
37 
38     return v1 * f1 + v2 * f2 + t1 * f3 + t2 * f4;
39 }
40 } // namespace Math
41 BASE_END_NAMESPACE()
42 
43 #endif // API_BASE_MATH_SPLINE_H
44