org.graphstream.ui.geom.Vector2 Maven / Gradle / Ivy
/*
* This file is part of GraphStream .
*
* GraphStream is a library whose purpose is to handle static or dynamic
* graph, create them from scratch, file or any source and display them.
*
* This program is free software distributed under the terms of two licenses, the
* CeCILL-C license that fits European law, and the GNU Lesser General Public
* License. You can use, modify and/ or redistribute the software under the terms
* of the CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
* URL or under the terms of the GNU LGPL as published by
* the Free Software Foundation, either version 3 of the License, or (at your
* option) 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see
* @author Guilhelm Savin
* @author Richard O. Legendi
* @author Alex Bowen
* @author kitskub
* @author Hicham Brahimi
*/
package org.graphstream.ui.geom;
import java.util.Arrays;
public class Vector2 implements java.io.Serializable {
// Attributes
private static final long serialVersionUID = 8839258036865851454L;
/**
* Sequence of 3 coefficients.
*/
public double data[];
// Constructors
/**
* New zero vector.
*/
public Vector2() {
data = new double[2];
data[0] = 0;
data[1] = 0;
}
/**
* New (x,y) vector.
*/
public Vector2(double x, double y) {
data = new double[2];
data[0] = x;
data[1] = y;
}
/**
* New vector copy of other.
*/
public Vector2(Vector2 other) {
data = new double[2];
copy(other);
}
/**
* New vector copy of point.
*/
public Vector2(Point2 point) {
data = new double[2];
copy(point);
}
public Vector2(Point2 from, Point2 to) {
data = new double[2];
data[0] = to.x - from.x;
data[1] = to.y - from.y;
}
// Predicates
/**
* Are all components to zero?.
*/
public boolean isZero() {
return (data[0] == 0 && data[1] == 0);
}
/**
* Is this equal to other ?
*/
@Override
public boolean equals(Object other) {
Vector2 v;
if (!(other instanceof Vector2)) {
return false;
}
v = (Vector2) other;
return (data[0] == v.data[0] && data[1] == v.data[1]);
}
/**
* Is i the index of a component ?
*
* In other words, is i >= 0 && < than #count() ?
*/
public boolean validComponent(int i) {
return (i >= 0 && i < 2);
}
// Accessors:
/**
* i-th element.
*/
public double at(int i) {
return data[i];
}
public double x() {
return data[0];
}
public double y() {
return data[1];
}
@Override
public Object clone() {
return new Vector2(this);
}
// Accessors
public double dotProduct(double ox, double oy) {
return ((data[0] * ox) + (data[1] * oy));
}
/**
* Dot product of this and other.
*/
public double dotProduct(Vector2 other) {
return ((data[0] * other.data[0]) + (data[1] * other.data[1]));
}
/**
* Cartesian length.
*/
public double length() {
return Math.sqrt((data[0] * data[0]) + (data[1] * data[1]));
}
// Commands
/**
* Assign value to all elements.
*/
public void fill(double value) {
data[0] = data[1] = value;
}
/**
* Explicitly set the i-th component to value.
*/
public void set(int i, double value) {
data[i] = value;
}
/**
* Explicitly set the three components.
*/
public void set(double x, double y) {
data[0] = x;
data[1] = y;
}
/**
* Add each element of other to the corresponding element of this.
*/
public void add(Vector2 other) {
data[0] += other.data[0];
data[1] += other.data[1];
}
/**
* Subtract each element of other to the corresponding element of this.
*/
public void sub(Vector2 other) {
data[0] -= other.data[0];
data[1] -= other.data[1];
}
/**
* Multiply each element of this by the corresponding element of other.
*/
public void mult(Vector2 other) {
data[0] *= other.data[0];
data[1] *= other.data[1];
}
/**
* Add value to each element.
*/
public void scalarAdd(double value) {
data[0] += value;
data[1] += value;
}
/**
* Substract value to each element.
*/
public void scalarSub(double value) {
data[0] -= value;
data[1] -= value;
}
/**
* Multiply each element by value.
*/
public void scalarMult(double value) {
data[0] *= value;
data[1] *= value;
}
/**
* Divide each element by value.
*/
public void scalarDiv(double value) {
data[0] /= value;
data[1] /= value;
}
/**
* Transform this into an unit vector.
*
* @return the vector length.
*/
public double normalize() {
double len = length();
if (len != 0) {
data[0] /= len;
data[1] /= len;
}
return len;
}
// Utility
/**
* Make this a copy of other.
*/
public void copy(Vector2 other) {
data[0] = other.data[0];
data[1] = other.data[1];
}
/**
* Make this a copy of point.
*/
public void copy(Point2 point) {
data[0] = point.x;
data[1] = point.y;
}
// Misc.
@Override
public String toString() {
StringBuffer sb = new StringBuffer("[");
sb.append(data[0]);
sb.append('|');
sb.append(data[1]);
sb.append(']');
return sb.toString();
}
@Override
public int hashCode() {
return data != null ? Arrays.hashCode(data) : 0;
}
}