/*
* Copyright (c) 2010 William Bittle http://www.dyn4j.org/
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are permitted
* provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice, this list of conditions
* and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice, this list of conditions
* and the following disclaimer in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of dyn4j nor the names of its contributors may be used to endorse or
* promote products derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.dyn4j.game2d;
/**
* Class used to convert units.
* <p>
* Dyn4j by default uses meters-kilograms-seconds (MKS) units. This class can be used
* to convert to and from MKS.
* @author William Bittle
* @version 1.0.3
* @since 1.0.0
*/
public class UnitConversion {
/** 1 foot = {@value #FOOT_TO_METER} meters */
public static final double FOOT_TO_METER = 0.0254 * 12.0;
/** 1 meter = {@value #METER_TO_FOOT} feet */
public static final double METER_TO_FOOT = 1.0 / FOOT_TO_METER;
/** 1 slug = {@value #SLUG_TO_KILOGRAM} kilograms */
public static final double SLUG_TO_KILOGRAM = 14.5939029;
/** 1 kilogram = {@value #KILOGRAM_TO_SLUG} slugs */
public static final double KILOGRAM_TO_SLUG = 1.0 / SLUG_TO_KILOGRAM;
/** 1 pound-mass = {@value #POUND_TO_KILOGRAM} kilograms */
public static final double POUND_TO_KILOGRAM = 0.45359237;
/** 1 kilogram = {@value #KILOGRAM_TO_POUND} pounds */
public static final double KILOGRAM_TO_POUND = 1.0 / POUND_TO_KILOGRAM;
/** 1 pound-force = {@value #POUND_TO_NEWTON} newtons */
public static final double POUND_TO_NEWTON = 4.448222;
/** 1 newton = {@value #NEWTON_TO_POUND} pound-force */
public static final double NEWTON_TO_POUND = 1.0 / POUND_TO_NEWTON;
/** 1 foot-pound = {@value #FOOT_POUND_TO_NEWTON_METER} newton-meters */
public static final double FOOT_POUND_TO_NEWTON_METER = 0.7375621;
/** 1 newton-meter = {@value #NEWTON_METER_TO_FOOT_POUND} foot-pounds */
public static final double NEWTON_METER_TO_FOOT_POUND = 1.0 / FOOT_POUND_TO_NEWTON_METER;
// FPS (mixture of Gravitational and Engineering approaches) to MKS
// Length Conversions
/**
* Converts feet to meters.
* @param feet the length value in feet
* @return double the length value in meters
*/
public static final double feetToMeters(double feet) {
return feet * FOOT_TO_METER;
}
// Mass Conversions
/**
* Converts slugs to kilograms.
* @param slugs the mass value in slugs
* @return double the mass value in kilograms
*/
public static final double slugsToKilograms(double slugs) {
return slugs * SLUG_TO_KILOGRAM;
}
/**
* Converts pound-mass to kilograms.
* @param pound the mass value in pound-masses
* @return double the mass value in kilograms
*/
public static final double poundsToKilograms(double pound) {
return pound * POUND_TO_KILOGRAM;
}
// Velocity Conversions
/**
* Converts feet per second to meters per second.
* @param feetPerSecond the velocity in feet per second
* @return double the velocity in meters per second
*/
public static final double feetPerSecondToMetersPerSecond(double feetPerSecond) {
return feetPerSecond * METER_TO_FOOT;
}
// Force Conversions
/**
* Converts pound-force to newtons.
* @param pound the force value in pound-force
* @return double the force value in newtons
*/
public static final double poundsToNewtons(double pound) {
return pound * POUND_TO_NEWTON;
}
// Torque Conversions
/**
* Converts foot-pounds to newton-meters.
* @param footPound the torque value in foot-pounds
* @return double the torque value in newton-meters
*/
public static final double footPoundsToNewtonMeters(double footPound) {
return footPound * FOOT_POUND_TO_NEWTON_METER;
}
// MKS to FPS (mixture of Gravitational and Engineering approaches)
// Length Conversions
/**
* Converts meters to feet.
* @param meters the length value in meters
* @return double the length value in feet
*/
public static final double metersToFeet(double meters) {
return meters * METER_TO_FOOT;
}
// Mass Conversions
/**
* Converts kilograms to slugs.
* @param kilograms the mass value in kilograms
* @return double the mass value in slugs
*/
public static final double kilogramsToSlugs(double kilograms) {
return kilograms * KILOGRAM_TO_SLUG;
}
/**
* Converts kilograms to pound-mass.
* @param kilograms the mass value in kilograms
* @return double the mass value in pound-masses
*/
public static final double kilogramsToPounds(double kilograms) {
return kilograms * KILOGRAM_TO_POUND;
}
// Velocity Conversions
/**
* Converts meters per second to feet per second.
* @param metersPerSecond the velocity in meters per second
* @return double the velocity in feet per second
*/
public static final double metersPerSecondToFeetPerSecond(double metersPerSecond) {
return metersPerSecond * FOOT_TO_METER;
}
// Force Conversions
/**
* Converts newtons to pound-force.
* @param newtons the force value in newtons
* @return double the force value in pound-force
*/
public static final double newtonsToPounds(double newtons) {
return newtons * NEWTON_TO_POUND;
}
// Torque Conversions
/**
* Converts newton-meters to foot-pounds.
* @param newtonMeters the torque value in newton-meters
* @return double the torque value in foot-pounds
*/
public static final double newtonMetersToFootPounds(double newtonMeters) {
return newtonMeters * NEWTON_METER_TO_FOOT_POUND;
}
}
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