Java Angle Reduce reduceAngle(float theta)

Description

Reduces the given angle into the -PI/4 ...

License

Open Source License

Parameter

Parameter	Description
theta	angle in radians

Return

reduced angle

Declaration

public static final float reduceAngle(float theta) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2012 Andreas H?hmann//from w  ww.  j  ava  2  s. co  m
 *
 * All rights reserved. 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.
 * 
 *******************************************************************************/

public class Main {
    /**
     * PI
     */
    public static final float PI = 3.14159265358979323846f;
    /**
     * PI/2
     */
    public static final float HALF_PI = PI / 2;
    /**
     * PI*2
     */
    public static final float TWO_PI = PI * 2;

    /**
     * Reduces the given angle into the -PI/4 ... PI/4 interval. This method is use by {@link #sin(float)} &
     * {@link #cos(float)}.
     * 
     * @param theta
     *          angle in radians
     * @return reduced angle
     * @see #sin(float)
     * @see #cos(float)
     */
    public static final float reduceAngle(float theta) {
        theta %= TWO_PI;
        if (abs(theta) > PI) {
            theta = theta - TWO_PI;
        }
        if (abs(theta) > HALF_PI) {
            theta = PI - theta;
        }
        return theta;
    }

    /**
     * @param x
     * @return absolute value of x
     */
    public static final double abs(final double x) {
        return x < 0 ? -x : x;
    }

    /**
     * @param x
     * @return absolute value of x
     */
    public static final float abs(final float x) {
        return x < 0 ? -x : x;
    }

    /**
     * @param x
     * @return absolute value of x
     */
    public static final int abs(final int x) {
        final int y = x >> 31;
        return (x ^ y) - y;
    }
}

Related

1. reduceAngle(double theta)
2. reduceAngle(double theta)
3. reduceAngle(float angle)