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/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.util;
import java.util.Random;
/**
* A class that contains utility methods related to numbers.
*
* @hide Pending API council approval
*/
public final class MathUtils {
private static final Random sRandom = new Random();
private static final float DEG_TO_RAD = 3.1415926f / 180.0f;
private static final float RAD_TO_DEG = 180.0f / 3.1415926f;
private MathUtils() {
}
public static float abs(float v) {
return v > 0 ? v : -v;
}
public static int constrain(int amount, int low, int high) {
return amount < low ? low : (amount > high ? high : amount);
}
public static long constrain(long amount, long low, long high) {
return amount < low ? low : (amount > high ? high : amount);
}
public static float constrain(float amount, float low, float high) {
return amount < low ? low : (amount > high ? high : amount);
}
public static float log(float a) {
return (float) Math.log(a);
}
public static float exp(float a) {
return (float) Math.exp(a);
}
public static float pow(float a, float b) {
return (float) Math.pow(a, b);
}
public static float max(float a, float b) {
return a > b ? a : b;
}
public static float max(int a, int b) {
return a > b ? a : b;
}
public static float max(float a, float b, float c) {
return a > b ? (a > c ? a : c) : (b > c ? b : c);
}
public static float max(int a, int b, int c) {
return a > b ? (a > c ? a : c) : (b > c ? b : c);
}
public static float min(float a, float b) {
return a < b ? a : b;
}
public static float min(int a, int b) {
return a < b ? a : b;
}
public static float min(float a, float b, float c) {
return a < b ? (a < c ? a : c) : (b < c ? b : c);
}
public static float min(int a, int b, int c) {
return a < b ? (a < c ? a : c) : (b < c ? b : c);
}
public static float dist(float x1, float y1, float x2, float y2) {
final float x = (x2 - x1);
final float y = (y2 - y1);
return (float) Math.hypot(x, y);
}
public static float dist(float x1, float y1, float z1, float x2, float y2, float z2) {
final float x = (x2 - x1);
final float y = (y2 - y1);
final float z = (z2 - z1);
return (float) Math.sqrt(x * x + y * y + z * z);
}
public static float mag(float a, float b) {
return (float) Math.hypot(a, b);
}
public static float mag(float a, float b, float c) {
return (float) Math.sqrt(a * a + b * b + c * c);
}
public static float sq(float v) {
return v * v;
}
public static float dot(float v1x, float v1y, float v2x, float v2y) {
return v1x * v2x + v1y * v2y;
}
public static float cross(float v1x, float v1y, float v2x, float v2y) {
return v1x * v2y - v1y * v2x;
}
public static float radians(float degrees) {
return degrees * DEG_TO_RAD;
}
public static float degrees(float radians) {
return radians * RAD_TO_DEG;
}
public static float acos(float value) {
return (float) Math.acos(value);
}
public static float asin(float value) {
return (float) Math.asin(value);
}
public static float atan(float value) {
return (float) Math.atan(value);
}
public static float atan2(float a, float b) {
return (float) Math.atan2(a, b);
}
public static float tan(float angle) {
return (float) Math.tan(angle);
}
public static float lerp(float start, float stop, float amount) {
return start + (stop - start) * amount;
}
public static float norm(float start, float stop, float value) {
return (value - start) / (stop - start);
}
public static float map(float minStart, float minStop, float maxStart, float maxStop, float value) {
return maxStart + (maxStart - maxStop) * ((value - minStart) / (minStop - minStart));
}
public static int random(int howbig) {
return (int) (sRandom.nextFloat() * howbig);
}
public static int random(int howsmall, int howbig) {
if (howsmall >= howbig) return howsmall;
return (int) (sRandom.nextFloat() * (howbig - howsmall) + howsmall);
}
public static float random(float howbig) {
return sRandom.nextFloat() * howbig;
}
public static float random(float howsmall, float howbig) {
if (howsmall >= howbig) return howsmall;
return sRandom.nextFloat() * (howbig - howsmall) + howsmall;
}
public static void randomSeed(long seed) {
sRandom.setSeed(seed);
}
}
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