1/*
2 * Copyright (C) 2010 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
17package com.replica.replicaisland;
18
19/** A collection of miscellaneous utility functions. */
20public class Utils {
21    private static final float EPSILON = 0.0001f;
22
23    public final static boolean close(float a, float b) {
24        return close(a, b, EPSILON);
25    }
26
27    public final static boolean close(float a, float b, float epsilon) {
28        return Math.abs(a - b) < epsilon;
29    }
30
31    public final static int sign(float a) {
32        if (a >= 0.0f) {
33            return 1;
34        } else {
35            return -1;
36        }
37    }
38
39    public final static int clamp(int value, int min, int max) {
40        int result = value;
41        if (min == max) {
42            if (value != min) {
43                result = min;
44            }
45        } else if (min < max) {
46            if (value < min) {
47                result = min;
48            } else if (value > max) {
49                result = max;
50            }
51        } else {
52            result = clamp(value, max, min);
53        }
54
55        return result;
56    }
57
58
59    public final static int byteArrayToInt(byte[] b) {
60        if (b.length != 4) {
61            return 0;
62        }
63
64        // Same as DataInputStream's 'readInt' method
65        /*int i = (((b[0] & 0xff) << 24) | ((b[1] & 0xff) << 16) | ((b[2] & 0xff) << 8)
66                | (b[3] & 0xff));*/
67
68        // little endian
69        int i = (((b[3] & 0xff) << 24) | ((b[2] & 0xff) << 16) | ((b[1] & 0xff) << 8)
70                | (b[0] & 0xff));
71
72        return i;
73    }
74
75    public final static float byteArrayToFloat(byte[] b) {
76
77        // intBitsToFloat() converts bits as follows:
78        /*
79        int s = ((i >> 31) == 0) ? 1 : -1;
80        int e = ((i >> 23) & 0xff);
81        int m = (e == 0) ? (i & 0x7fffff) << 1 : (i & 0x7fffff) | 0x800000;
82        */
83
84        return Float.intBitsToFloat(byteArrayToInt(b));
85    }
86
87    public final static float framesToTime(int framesPerSecond, int frameCount) {
88        return (1.0f / framesPerSecond) * frameCount;
89    }
90
91}
92