Here you can find the source of cross(int x1, int y1, int x2, int y2)
public static double cross(int x1, int y1, int x2, int y2)
//package com.java2s; /*/*from w w w . ja v a 2 s. com*/ * ..::jDrawingLib::.. * * Copyright (C) Federico Vera 2012 - 2014 <dktcoding [at] gmail> * * 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, either version 3 of the License, or any later * version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program. If not, see <http://www.gnu.org/licenses/>. */ public class Main { public static double cross(int x1, int y1, int x2, int y2) { return (x1 * y2) - (y1 * x2); } }