MathUtil.java

/*******************************************************************************
 * Copyright (c) 2016 Weasis Team and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     Nicolas Roduit - initial API and implementation
 *******************************************************************************/
package org.weasis.core.api.gui.util;

import java.awt.geom.Point2D;

/**
 * The Class MathUtil.
 *
 * @author Nicolas Roduit
 */
public class MathUtil {
    public static final double DOUBLE_EPSILON = 1e-6;
    public static final double FLOAT_EPSILON = 1e-5;

    private MathUtil() {
    }

    public static boolean isEqualToZero(float val) {
        return Math.copySign(val, 1.0) < FLOAT_EPSILON;
    }

    public static boolean isDifferentFromZero(float val) {
        return Math.copySign(val, 1.0) > FLOAT_EPSILON;
    }

    public static boolean isEqual(float a, float b) {
        // Math.copySign is similar to Math.abs(x), but with different NaN semantics
        return Math.copySign(a - b, 1.0) <= FLOAT_EPSILON || (a == b) // infinities equal themselves
            || (Float.isNaN(a) && Float.isNaN(b));
    }

    public static boolean isDifferent(float a, float b) {
        // Math.copySign is similar to Math.abs(x), but with different NaN semantics
        return Math.copySign(a - b, 1.0) >= FLOAT_EPSILON;
    }

    public static boolean isEqualToZero(double val) {
        return Math.copySign(val, 1.0) < DOUBLE_EPSILON;
    }

    public static boolean isDifferentFromZero(double val) {
        return Math.copySign(val, 1.0) > DOUBLE_EPSILON;
    }

    public static boolean isEqual(double a, double b) {
        // Math.copySign is imilar to Math.abs(x), but with different NaN semantics
        return Math.copySign(a - b, 1.0) <= DOUBLE_EPSILON || (a == b) // infinities equal themselves
            || (Double.isNaN(a) && Double.isNaN(b));
    }

    public static boolean isDifferent(double a, double b) {
        // Math.copySign is similar to Math.abs(x), but with different NaN semantics
        return Math.copySign(a - b, 1.0) >= DOUBLE_EPSILON;
    }

    public static double computeDistanceFloat(double x1, double y1, double x2, double y2) {
        return Point2D.distance(x1, y1, x2, y2);
    }

    public static double getOrientation(Point2D p1, Point2D p2) {
        return (p1 != null && p2 != null) ? getOrientation(p1.getX(), p1.getY(), p2.getX(), p2.getY()) : null;
    }

    public static double getOrientation(double x1, double y1, double x2, double y2) {
        // Use arctan2 to handle to handle possible negative values
        double teta = Math.atan2(y1 - y2, x1 - x2);
        double angle = Math.toDegrees(teta); // convert from radians to degrees
        // Return the orientation from 0 to 180 degrees
        if (angle < 0) {
            angle = -angle;
        } else {
            angle = 180 - angle;
        }
        return angle;
    }

    public static double getAzimuth(Point2D p1, Point2D p2) {
        return (p1 != null && p2 != null) ? getAzimuth(p1.getX(), p1.getY(), p2.getX(), p2.getY()) : null;
    }

    public static double getAzimuth(double x1, double y1, double x2, double y2) {
        double angle = Math.toDegrees(Math.atan2(y2 - y1, x2 - x1));
        angle = (angle + 450.0) % 360.0;
        return angle;
    }

    public static float checkMin0(float val) {
        return (val < 0.0f) ? 0.0f : val;
    }

    public static float checkMax(float val, float max) {
        return (val > max) ? max : val;
    }

    public static float checkMinMax(float val, float min, float max) {
        float res = val;
        if (res < min) {
            res = min;
        }
        if (res > max) {
            res = max;
        }
        return res;
    }

    public static int checkMinMax(int val, int min, int max) {
        int res = val;
        if (res < min) {
            res = min;
        }
        if (res > max) {
            res = max;
        }
        return res;
    }
}