/*
* $RCSfile: Vector2f.java,v $
*
* Copyright 1997-2008 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
* $Revision: 1.5 $
* $Date: 2008/02/28 20:18:51 $
* $State: Exp $
*/
package javax.vecmath;
import java.lang.Math;
/**
* A 2-element vector that is represented by single-precision floating point x,y
* coordinates.
*
*/
public class Vector2f extends Tuple2f implements java.io.Serializable {
// Combatible with 1.1
static final long serialVersionUID = -2168194326883512320L;
/**
* Constructs and initializes a Vector2f from the specified xy coordinates.
*
* @param x
* the x coordinate
* @param y
* the y coordinate
*/
public Vector2f(float x, float y) {
super(x, y);
}
/**
* Constructs and initializes a Vector2f from the specified array.
*
* @param v
* the array of length 2 containing xy in order
*/
public Vector2f(float[] v) {
super(v);
}
/**
* Constructs and initializes a Vector2f from the specified Vector2f.
*
* @param v1
* the Vector2f containing the initialization x y data
*/
public Vector2f(Vector2f v1) {
super(v1);
}
/**
* Constructs and initializes a Vector2f from the specified Vector2d.
*
* @param v1
* the Vector2d containing the initialization x y data
*/
public Vector2f(Vector2d v1) {
super(v1);
}
/**
* Constructs and initializes a Vector2f from the specified Tuple2f.
*
* @param t1
* the Tuple2f containing the initialization x y data
*/
public Vector2f(Tuple2f t1) {
super(t1);
}
/**
* Constructs and initializes a Vector2f from the specified Tuple2d.
*
* @param t1
* the Tuple2d containing the initialization x y data
*/
public Vector2f(Tuple2d t1) {
super(t1);
}
/**
* Constructs and initializes a Vector2f to (0,0).
*/
public Vector2f() {
super();
}
/**
* Computes the dot product of the this vector and vector v1.
*
* @param v1
* the other vector
*/
public final float dot(Vector2f v1) {
return (this.x * v1.x + this.y * v1.y);
}
/**
* Returns the length of this vector.
*
* @return the length of this vector
*/
public final float length() {
return (float) Math.sqrt(this.x * this.x + this.y * this.y);
}
/**
* Returns the squared length of this vector.
*
* @return the squared length of this vector
*/
public final float lengthSquared() {
return (this.x * this.x + this.y * this.y);
}
/**
* Sets the value of this vector to the normalization of vector v1.
*
* @param v1
* the un-normalized vector
*/
public final void normalize(Vector2f v1) {
float norm;
norm = (float) (1.0 / Math.sqrt(v1.x * v1.x + v1.y * v1.y));
this.x = v1.x * norm;
this.y = v1.y * norm;
}
/**
* Normalizes this vector in place.
*/
public final void normalize() {
float norm;
norm = (float) (1.0 / Math.sqrt(this.x * this.x + this.y * this.y));
this.x *= norm;
this.y *= norm;
}
public final Vector2f normalized(){
Vector2f a = new Vector2f(this);
a.normalize();
return a;
}
/**
* Returns the angle in radians between this vector and the vector parameter;
* the return value is constrained to the range [0,PI].
*
* @param v1
* the other vector
* @return the angle in radians in the range [0,PI]
*/
public final float angle(Vector2f v1) {
double vDot = this.dot(v1) / (this.length() * v1.length());
if (vDot < -1.0)
vDot = -1.0;
if (vDot > 1.0)
vDot = 1.0;
return ((float) (Math.acos(vDot)));
}
/**
* BDX conveniences:
*/
public final float angle(){
return angle(new Vector2f(1, 0));
}
public final float angleSigned(Vector2f refVec){
Vector2f rot = new Vector2f(-refVec.y, refVec.x);
float d = dot(rot);
if (d < 0)
return -angle(refVec);
return angle(refVec);
}
public final float angleSigned(){
return angleSigned(new Vector2f(1, 0));
}
public final Vector2f rotated(float radians) {
Vector3f to3D = new Vector3f(x, y, 0);
to3D.set(Matrix3f.rotation(new Vector3f(0, 0, 1), radians).mult(to3D));
return new Vector2f(to3D.x, to3D.y);
}
public final void rotate(float radians){
this.set(rotated(radians));
}
public final Vector2f plus(Vector2f b){
Vector2f a = new Vector2f(this);
a.add(b);
return a;
}
public final Vector2f minus(Vector2f b){
Vector2f a = new Vector2f(this);
a.sub(b);
return a;
}
public final void length(float n){
if (length() == 0)
return;
normalize();
scale(n);
}
public final Vector2f negated(){
Vector2f v = new Vector2f(this);
v.negate();
return v;
}
public final Vector2f mul(float n){
Vector2f v = new Vector2f(this);
v.x *= n;
v.y *= n;
return v;
}
public final Vector2f mul(Vector2f b){
Vector2f a = new Vector2f(this);
a.x *= b.x;
a.y *= b.y;
return a;
}
public final Vector2f div(Vector2f b){
Vector2f a = new Vector2f(this);
a.x /= b.x;
a.y /= b.y;
return a;
}
public final Vector2f reflected(Vector2f normal){
return normal.mul(-2 * this.dot(normal)).plus(this);
}
}