/*
* Copyright (c) 2009-2012 jMonkeyEngine
* 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 'jMonkeyEngine' 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 com.jme3.math;
import com.jme3.export.*;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.logging.Logger;
/**
* <code>Vector2f</code> defines a Vector for a two float value vector.
*
* @author Mark Powell
* @author Joshua Slack
*/
public final class Vector2f implements Savable, Cloneable, java.io.Serializable {
static final long serialVersionUID = 1;
private static final Logger logger = Logger.getLogger(Vector2f.class.getName());
public static final Vector2f ZERO = new Vector2f(0f, 0f);
public static final Vector2f UNIT_XY = new Vector2f(1f, 1f);
/**
* the x value of the vector.
*/
public float x;
/**
* the y value of the vector.
*/
public float y;
/**
* Creates a Vector2f with the given initial x and y values.
*
* @param x
* The x value of this Vector2f.
* @param y
* The y value of this Vector2f.
*/
public Vector2f(float x, float y) {
this.x = x;
this.y = y;
}
/**
* Creates a Vector2f with x and y set to 0. Equivalent to Vector2f(0,0).
*/
public Vector2f() {
x = y = 0;
}
/**
* Creates a new Vector2f that contains the passed vector's information
*
* @param vector2f
* The vector to copy
*/
public Vector2f(Vector2f vector2f) {
this.x = vector2f.x;
this.y = vector2f.y;
}
/**
* set the x and y values of the vector
*
* @param x
* the x value of the vector.
* @param y
* the y value of the vector.
* @return this vector
*/
public Vector2f set(float x, float y) {
this.x = x;
this.y = y;
return this;
}
/**
* set the x and y values of the vector from another vector
*
* @param vec
* the vector to copy from
* @return this vector
*/
public Vector2f set(Vector2f vec) {
this.x = vec.x;
this.y = vec.y;
return this;
}
/**
* <code>add</code> adds a provided vector to this vector creating a
* resultant vector which is returned. If the provided vector is null, null
* is returned.
*
* @param vec
* the vector to add to this.
* @return the resultant vector.
*/
public Vector2f add(Vector2f vec) {
if (null == vec) {
logger.warning("Provided vector is null, null returned.");
return null;
}
return new Vector2f(x + vec.x, y + vec.y);
}
/**
* <code>addLocal</code> adds a provided vector to this vector internally,
* and returns a handle to this vector for easy chaining of calls. If the
* provided vector is null, null is returned.
*
* @param vec
* the vector to add to this vector.
* @return this
*/
public Vector2f addLocal(Vector2f vec) {
if (null == vec) {
logger.warning("Provided vector is null, null returned.");
return null;
}
x += vec.x;
y += vec.y;
return this;
}
/**
* <code>addLocal</code> adds the provided values to this vector
* internally, and returns a handle to this vector for easy chaining of
* calls.
*
* @param addX
* value to add to x
* @param addY
* value to add to y
* @return this
*/
public Vector2f addLocal(float addX, float addY) {
x += addX;
y += addY;
return this;
}
/**
* <code>add</code> adds this vector by <code>vec</code> and stores the
* result in <code>result</code>.
*
* @param vec
* The vector to add.
* @param result
* The vector to store the result in.
* @return The result vector, after adding.
*/
public Vector2f add(Vector2f vec, Vector2f result) {
if (null == vec) {
logger.warning("Provided vector is null, null returned.");
return null;
}
if (result == null)
result = new Vector2f();
result.x = x + vec.x;
result.y = y + vec.y;
return result;
}
/**
* <code>dot</code> calculates the dot product of this vector with a
* provided vector. If the provided vector is null, 0 is returned.
*
* @param vec
* the vector to dot with this vector.
* @return the resultant dot product of this vector and a given vector.
*/
public float dot(Vector2f vec) {
if (null == vec) {
logger.warning("Provided vector is null, 0 returned.");
return 0;
}
return x * vec.x + y * vec.y;
}
/**
* <code>cross</code> calculates the cross product of this vector with a
* parameter vector v.
*
* @param v
* the vector to take the cross product of with this.
* @return the cross product vector.
*/
public Vector3f cross(Vector2f v) {
return new Vector3f(0, 0, determinant(v));
}
public float determinant(Vector2f v) {
return (x * v.y) - (y * v.x);
}
/**
* Sets this vector to the interpolation by changeAmnt from this to the
* finalVec this=(1-changeAmnt)*this + changeAmnt * finalVec
*
* @param finalVec
* The final vector to interpolate towards
* @param changeAmnt
* An amount between 0.0 - 1.0 representing a percentage change
* from this towards finalVec
*/
public Vector2f interpolateLocal(Vector2f finalVec, float changeAmnt) {
this.x = (1 - changeAmnt) * this.x + changeAmnt * finalVec.x;
this.y = (1 - changeAmnt) * this.y + changeAmnt * finalVec.y;
return this;
}
/**
* Sets this vector to the interpolation by changeAmnt from beginVec to
* finalVec this=(1-changeAmnt)*beginVec + changeAmnt * finalVec
*
* @param beginVec
* The begining vector (delta=0)
* @param finalVec
* The final vector to interpolate towards (delta=1)
* @param changeAmnt
* An amount between 0.0 - 1.0 representing a precentage change
* from beginVec towards finalVec
*/
public Vector2f interpolateLocal(Vector2f beginVec, Vector2f finalVec,
float changeAmnt) {
this.x = (1 - changeAmnt) * beginVec.x + changeAmnt * finalVec.x;
this.y = (1 - changeAmnt) * beginVec.y + changeAmnt * finalVec.y;
return this;
}
/**
* Check a vector... if it is null or its floats are NaN or infinite, return
* false. Else return true.
*
* @param vector
* the vector to check
* @return true or false as stated above.
*/
public static boolean isValidVector(Vector2f vector) {
if (vector == null) return false;
if (Float.isNaN(vector.x) ||
Float.isNaN(vector.y)) return false;
if (Float.isInfinite(vector.x) ||
Float.isInfinite(vector.y)) return false;
return true;
}
/**
* <code>length</code> calculates the magnitude of this vector.
*
* @return the length or magnitude of the vector.
*/
public float length() {
return FastMath.sqrt(lengthSquared());
}
/**
* <code>lengthSquared</code> calculates the squared value of the
* magnitude of the vector.
*
* @return the magnitude squared of the vector.
*/
public float lengthSquared() {
return x * x + y * y;
}
/**
* <code>distanceSquared</code> calculates the distance squared between
* this vector and vector v.
*
* @param v the second vector to determine the distance squared.
* @return the distance squared between the two vectors.
*/
public float distanceSquared(Vector2f v) {
double dx = x - v.x;
double dy = y - v.y;
return (float) (dx * dx + dy * dy);
}
/**
* <code>distanceSquared</code> calculates the distance squared between
* this vector and vector v.
*
* @param otherX The X coordinate of the v vector
* @param otherY The Y coordinate of the v vector
* @return the distance squared between the two vectors.
*/
public float distanceSquared(float otherX, float otherY) {
double dx = x - otherX;
double dy = y - otherY;
return (float) (dx * dx + dy * dy);
}
/**
* <code>distance</code> calculates the distance between this vector and
* vector v.
*
* @param v the second vector to determine the distance.
* @return the distance between the two vectors.
*/
public float distance(Vector2f v) {
return FastMath.sqrt(distanceSquared(v));
}
/**
* <code>mult</code> multiplies this vector by a scalar. The resultant
* vector is returned.
*
* @param scalar
* the value to multiply this vector by.
* @return the new vector.
*/
public Vector2f mult(float scalar) {
return new Vector2f(x * scalar, y * scalar);
}
/**
* <code>multLocal</code> multiplies this vector by a scalar internally,
* and returns a handle to this vector for easy chaining of calls.
*
* @param scalar
* the value to multiply this vector by.
* @return this
*/
public Vector2f multLocal(float scalar) {
x *= scalar;
y *= scalar;
return this;
}
/**
* <code>multLocal</code> multiplies a provided vector to this vector
* internally, and returns a handle to this vector for easy chaining of
* calls. If the provided vector is null, null is returned.
*
* @param vec
* the vector to mult to this vector.
* @return this
*/
public Vector2f multLocal(Vector2f vec) {
if (null == vec) {
logger.warning("Provided vector is null, null returned.");
return null;
}
x *= vec.x;
y *= vec.y;
return this;
}
/**
* Multiplies this Vector2f's x and y by the scalar and stores the result in
* product. The result is returned for chaining. Similar to
* product=this*scalar;
*
* @param scalar
* The scalar to multiply by.
* @param product
* The vector2f to store the result in.
* @return product, after multiplication.
*/
public Vector2f mult(float scalar, Vector2f product) {
if (null == product) {
product = new Vector2f();
}
product.x = x * scalar;
product.y = y * scalar;
return product;
}
/**
* <code>divide</code> divides the values of this vector by a scalar and
* returns the result. The values of this vector remain untouched.
*
* @param scalar
* the value to divide this vectors attributes by.
* @return the result <code>Vector</code>.
*/
public Vector2f divide(float scalar) {
return new Vector2f(x / scalar, y / scalar);
}
/**
* <code>divideLocal</code> divides this vector by a scalar internally,
* and returns a handle to this vector for easy chaining of calls. Dividing
* by zero will result in an exception.
*
* @param scalar
* the value to divides this vector by.
* @return this
*/
public Vector2f divideLocal(float scalar) {
x /= scalar;
y /= scalar;
return this;
}
/**
* <code>negate</code> returns the negative of this vector. All values are
* negated and set to a new vector.
*
* @return the negated vector.
*/
public Vector2f negate() {
return new Vector2f(-x, -y);
}
/**
* <code>negateLocal</code> negates the internal values of this vector.
*
* @return this.
*/
public Vector2f negateLocal() {
x = -x;
y = -y;
return this;
}
/**
* <code>subtract</code> subtracts the values of a given vector from those
* of this vector creating a new vector object. If the provided vector is
* null, an exception is thrown.
*
* @param vec
* the vector to subtract from this vector.
* @return the result vector.
*/
public Vector2f subtract(Vector2f vec) {
return subtract(vec, null);
}
/**
* <code>subtract</code> subtracts the values of a given vector from those
* of this vector storing the result in the given vector object. If the
* provided vector is null, an exception is thrown.
*
* @param vec
* the vector to subtract from this vector.
* @param store
* the vector to store the result in. It is safe for this to be
* the same as vec. If null, a new vector is created.
* @return the result vector.
*/
public Vector2f subtract(Vector2f vec, Vector2f store) {
if (store == null)
store = new Vector2f();
store.x = x - vec.x;
store.y = y - vec.y;
return store;
}
/**
* <code>subtract</code> subtracts the given x,y values from those of this
* vector creating a new vector object.
*
* @param valX
* value to subtract from x
* @param valY
* value to subtract from y
* @return this
*/
public Vector2f subtract(float valX, float valY) {
return new Vector2f(x - valX, y - valY);
}
/**
* <code>subtractLocal</code> subtracts a provided vector to this vector
* internally, and returns a handle to this vector for easy chaining of
* calls. If the provided vector is null, null is returned.
*
* @param vec
* the vector to subtract
* @return this
*/
public Vector2f subtractLocal(Vector2f vec) {
if (null == vec) {
logger.warning("Provided vector is null, null returned.");
return null;
}
x -= vec.x;
y -= vec.y;
return this;
}
/**
* <code>subtractLocal</code> subtracts the provided values from this
* vector internally, and returns a handle to this vector for easy chaining
* of calls.
*
* @param valX
* value to subtract from x
* @param valY
* value to subtract from y
* @return this
*/
public Vector2f subtractLocal(float valX, float valY) {
x -= valX;
y -= valY;
return this;
}
/**
* <code>normalize</code> returns the unit vector of this vector.
*
* @return unit vector of this vector.
*/
public Vector2f normalize() {
float length = length();
if (length != 0) {
return divide(length);
}
return divide(1);
}
/**
* <code>normalizeLocal</code> makes this vector into a unit vector of
* itself.
*
* @return this.
*/
public Vector2f normalizeLocal() {
float length = length();
if (length != 0) {
return divideLocal(length);
}
return divideLocal(1);
}
/**
* <code>smallestAngleBetween</code> returns (in radians) the minimum
* angle between two vectors. It is assumed that both this vector and the
* given vector are unit vectors (iow, normalized).
*
* @param otherVector
* a unit vector to find the angle against
* @return the angle in radians.
*/
public float smallestAngleBetween(Vector2f otherVector) {
float dotProduct = dot(otherVector);
float angle = FastMath.acos(dotProduct);
return angle;
}
/**
* <code>angleBetween</code> returns (in radians) the angle required to
* rotate a ray represented by this vector to lie colinear to a ray
* described by the given vector. It is assumed that both this vector and
* the given vector are unit vectors (iow, normalized).
*
* @param otherVector
* the "destination" unit vector
* @return the angle in radians.
*/
public float angleBetween(Vector2f otherVector) {
float angle = FastMath.atan2(otherVector.y, otherVector.x)
- FastMath.atan2(y, x);
return angle;
}
public float getX() {
return x;
}
public Vector2f setX(float x) {
this.x = x;
return this;
}
public float getY() {
return y;
}
public Vector2f setY(float y) {
this.y = y;
return this;
}
/**
* <code>getAngle</code> returns (in radians) the angle represented by
* this Vector2f as expressed by a conversion from rectangular coordinates (<code>x</code>, <code>y</code>)
* to polar coordinates (r, <i>theta</i>).
*
* @return the angle in radians. [-pi, pi)
*/
public float getAngle() {
return FastMath.atan2(y, x);
}
/**
* <code>zero</code> resets this vector's data to zero internally.
*/
public Vector2f zero() {
x = y = 0;
return this;
}
/**
* <code>hashCode</code> returns a unique code for this vector object
* based on it's values. If two vectors are logically equivalent, they will
* return the same hash code value.
*
* @return the hash code value of this vector.
*/
public int hashCode() {
int hash = 37;
hash += 37 * hash + Float.floatToIntBits(x);
hash += 37 * hash + Float.floatToIntBits(y);
return hash;
}
@Override
public Vector2f clone() {
try {
return (Vector2f) super.clone();
} catch (CloneNotSupportedException e) {
throw new AssertionError(); // can not happen
}
}
/**
* Saves this Vector2f into the given float[] object.
*
* @param floats
* The float[] to take this Vector2f. If null, a new float[2] is
* created.
* @return The array, with X, Y float values in that order
*/
public float[] toArray(float[] floats) {
if (floats == null) {
floats = new float[2];
}
floats[0] = x;
floats[1] = y;
return floats;
}
/**
* are these two vectors the same? they are is they both have the same x and
* y values.
*
* @param o
* the object to compare for equality
* @return true if they are equal
*/
public boolean equals(Object o) {
if (!(o instanceof Vector2f)) {
return false;
}
if (this == o) {
return true;
}
Vector2f comp = (Vector2f) o;
if (Float.compare(x, comp.x) != 0)
return false;
if (Float.compare(y, comp.y) != 0)
return false;
return true;
}
/**
* <code>toString</code> returns the string representation of this vector
* object. The format of the string is such: com.jme.math.Vector2f
* [X=XX.XXXX, Y=YY.YYYY]
*
* @return the string representation of this vector.
*/
public String toString() {
return "(" + x + ", " + y + ")";
}
/**
* Used with serialization. Not to be called manually.
*
* @param in
* ObjectInput
* @throws IOException
* @throws ClassNotFoundException
* @see java.io.Externalizable
*/
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
x = in.readFloat();
y = in.readFloat();
}
/**
* Used with serialization. Not to be called manually.
*
* @param out
* ObjectOutput
* @throws IOException
* @see java.io.Externalizable
*/
public void writeExternal(ObjectOutput out) throws IOException {
out.writeFloat(x);
out.writeFloat(y);
}
public void write(JmeExporter e) throws IOException {
OutputCapsule capsule = e.getCapsule(this);
capsule.write(x, "x", 0);
capsule.write(y, "y", 0);
}
public void read(JmeImporter e) throws IOException {
InputCapsule capsule = e.getCapsule(this);
x = capsule.readFloat("x", 0);
y = capsule.readFloat("y", 0);
}
public void rotateAroundOrigin(float angle, boolean cw) {
if (cw)
angle = -angle;
float newX = FastMath.cos(angle) * x - FastMath.sin(angle) * y;
float newY = FastMath.sin(angle) * x + FastMath.cos(angle) * y;
x = newX;
y = newY;
}
}