1 /*
2  * Copyright (C) 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 package com.android.camera.ui.motion;
18 
19 /**
20  * Simple functions that produce values along a curve for any given input and can compute input
21  * times for a given output value.
22  */
23 public interface UnitCurve {
24 
25     /**
26      * Produce a unit value of this curve at time t. The function should always return a valid
27      * return value for any valid t input.
28      *
29      * @param t ratio of time passed from (0..1)
30      * @return the unit value at t.
31      */
valueAt(float t)32     float valueAt(float t);
33 
34     /**
35      * If possible, find a value for t such that valueAt(t) == value or best guess.
36      *
37      * @param value to match to the output of valueAt(t)
38      * @return t where valueAt(t) == value or throw.
39      */
tAt(float value)40     float tAt(float value);
41 }
42