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1 /*
2  * Copyright (C) 2007 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 android.util;
18 
19 /**
20  * Math routines similar to those found in {@link java.lang.Math}. On
21  * versions of Android with a JIT, these are significantly slower than
22  * the equivalent {@code Math} functions, which should be used in preference
23  * to these.
24  */
25 public class FloatMath {
26 
27     /** Prevents instantiation. */
FloatMath()28     private FloatMath() {}
29 
30     /**
31      * Returns the float conversion of the most positive (i.e. closest to
32      * positive infinity) integer value which is less than the argument.
33      *
34      * @param value to be converted
35      * @return the floor of value
36      */
floor(float value)37     public static native float floor(float value);
38 
39     /**
40      * Returns the float conversion of the most negative (i.e. closest to
41      * negative infinity) integer value which is greater than the argument.
42      *
43      * @param value to be converted
44      * @return the ceiling of value
45      */
ceil(float value)46     public static native float ceil(float value);
47 
48     /**
49      * Returns the closest float approximation of the sine of the argument.
50      *
51      * @param angle to compute the cosine of, in radians
52      * @return the sine of angle
53      */
sin(float angle)54     public static native float sin(float angle);
55 
56     /**
57      * Returns the closest float approximation of the cosine of the argument.
58      *
59      * @param angle to compute the cosine of, in radians
60      * @return the cosine of angle
61      */
cos(float angle)62     public static native float cos(float angle);
63 
64     /**
65      * Returns the closest float approximation of the square root of the
66      * argument.
67      *
68      * @param value to compute sqrt of
69      * @return the square root of value
70      */
sqrt(float value)71     public static native float sqrt(float value);
72 
73     /**
74      * Returns the closest float approximation of the raising "e" to the power
75      * of the argument.
76      *
77      * @param value to compute the exponential of
78      * @return the exponential of value
79      */
exp(float value)80     public static native float exp(float value);
81 
82     /**
83      * Returns the closest float approximation of the result of raising {@code
84      * x} to the power of {@code y}.
85      *
86      * @param x the base of the operation.
87      * @param y the exponent of the operation.
88      * @return {@code x} to the power of {@code y}.
89      */
pow(float x, float y)90     public static native float pow(float x, float y);
91 
92     /**
93      * Returns {@code sqrt(}<i>{@code x}</i><sup>{@code 2}</sup>{@code +} <i>
94      * {@code y}</i><sup>{@code 2}</sup>{@code )}.
95      *
96      * @param x a float number
97      * @param y a float number
98      * @return the hypotenuse
99      */
hypot(float x, float y)100     public static native float hypot(float x, float y);
101 }
102