1 /*
2  * Copyright (c) 2023 - 2024 the ThorVG project. All rights reserved.
3 
4  * Permission is hereby granted, free of charge, to any person obtaining a copy
5  * of this software and associated documentation files (the "Software"), to deal
6  * in the Software without restriction, including without limitation the rights
7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8  * copies of the Software, and to permit persons to whom the Software is
9  * furnished to do so, subject to the following conditions:
10 
11  * The above copyright notice and this permission notice shall be included in all
12  * copies or substantial portions of the Software.
13 
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20  * SOFTWARE.
21  */
22 
23 #include "../../lv_conf_internal.h"
24 #if LV_USE_THORVG_INTERNAL
25 
26 #ifndef _TVG_LOTTIE_INTERPOLATOR_H_
27 #define _TVG_LOTTIE_INTERPOLATOR_H_
28 
29 #define SPLINE_TABLE_SIZE 11
30 
31 struct LottieInterpolator
32 {
33     char* key;
34     Point outTangent, inTangent;
35 
36     float progress(float t);
37     void set(const char* key, Point& inTangent, Point& outTangent);
38 
39 private:
40     static constexpr float SAMPLE_STEP_SIZE = 1.0f / float(SPLINE_TABLE_SIZE - 1);
41     float samples[SPLINE_TABLE_SIZE];
42 
43     float getTForX(float aX);
44     float binarySubdivide(float aX, float aA, float aB);
45     float NewtonRaphsonIterate(float aX, float aGuessT);
46 };
47 
48 #endif //_TVG_LOTTIE_INTERPOLATOR_H_
49 
50 #endif /* LV_USE_THORVG_INTERNAL */
51 
52