/*
GeoGebra - Dynamic Mathematics for Everyone
http://www.geogebra.org
This file is part of GeoGebra.
This program is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation.
*/
/*
* Area of polygon P[0], ..., P[n]
*
*/
package org.geogebra.common.kernel.algos;
import org.geogebra.common.kernel.Construction;
import org.geogebra.common.kernel.Kernel;
import org.geogebra.common.kernel.arithmetic.MyDouble;
import org.geogebra.common.kernel.commands.Commands;
import org.geogebra.common.kernel.geos.GeoNumberValue;
/**
* Computes Mod[a, b]
*
* @author Markus Hohenwarter
*/
public class AlgoMod extends AlgoTwoNumFunction {
/**
* Creates new mod algo
*
* @param cons
* construction
* @param label
* output label
* @param a
* dividend
* @param b
* divisor
*/
public AlgoMod(Construction cons, String label, GeoNumberValue a,
GeoNumberValue b) {
super(cons, label, a, b);
}
@Override
public Commands getClassName() {
return Commands.Mod;
}
@Override
public final void compute() {
if (input[0].isDefined() && input[1].isDefined()) {
// removed as causes problems with old files
// double mod = Math.round(a.getDouble());
// double bInt = Math.abs(Math.round(b.getDouble()));
double aVal = Kernel.checkInteger(a.getDouble());
double bAbs = Kernel.checkInteger(Math.abs(b.getDouble()));
if (Math.abs(aVal) > MyDouble.LARGEST_INTEGER
|| bAbs > MyDouble.LARGEST_INTEGER) {
num.setUndefined();
return;
}
double mod = aVal % bAbs;
// https://docs.oracle.com/javase/specs/jls/se7/html/jls-15.html#jls-15.17.3
// It follows from this rule that the result of the remainder
// operation can be negative only if the dividend is negative, and
// can be positive only if the dividend is positive.
if (mod < 0) {
mod += bAbs;
}
num.setValue(mod);
} else {
num.setUndefined();
}
}
}