com.jme3.math.Vector2f Maven / Gradle / Ivy
Show all versions of jme3-core Show documentation
/*
* Copyright (c) 2009-2021 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.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.logging.Logger;
/**
* A vector composed of 2 single-precision components, used to represent
* locations, offsets, directions, and rotations in 2-dimensional space.
*
* Methods with names ending in "Local" modify the current instance. They are
* used to avoid creating garbage.
*
* @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());
/**
* Shared instance of the all-zero vector (0,0). Do not modify!
*/
public static final Vector2f ZERO = new Vector2f(0f, 0f);
/**
* Shared instance of the all-ones vector (1,1). Do not modify!
*/
public static final Vector2f UNIT_XY = new Vector2f(1f, 1f);
/**
* The first (X) component.
*/
public float x;
/**
* The 2nd (Y) component.
*/
public float y;
/**
* Instantiates a vector with specified components.
*
* @param x the desired X component
* @param y the desired Y component
*/
public Vector2f(float x, float y) {
this.x = x;
this.y = y;
}
/**
* Instantiates an all-zero vector (0,0).
*/
public Vector2f() {
x = y = 0;
}
/**
* Instantiates a copy of the argument.
*
* @param vector2f the vector to copy (not null, unaffected)
*/
public Vector2f(Vector2f vector2f) {
this.x = vector2f.x;
this.y = vector2f.y;
}
/**
* Sets both components to specified values.
*
* @param x the desired X component
* @param y the desired Y component
* @return the (modified) current instance (for chaining)
*/
public Vector2f set(float x, float y) {
this.x = x;
this.y = y;
return this;
}
/**
* Copies both components from the argument.
*
* @param vec the Vector2f to copy (not null, unaffected)
* @return the (modified) current instance (for chaining)
*/
public Vector2f set(Vector2f vec) {
this.x = vec.x;
this.y = vec.y;
return this;
}
/**
* Adds the argument and returns the sum as a new instance. If the argument
* is null, null is returned. Either way, the current instance is
* unaffected.
*
* @param vec the vector to add (unaffected) or null for none
* @return a new Vector2f or null
*/
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);
}
/**
* Adds the argument and returns the (modified) current instance. If the
* argument is null, null is returned.
*
* @param vec the vector to add (unaffected unless it's {@code this}) or
* null for none
* @return the (modified) current instance or null
*/
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;
}
/**
* Adds specified amounts to the vector's components and returns the
* (modified) current instance.
*
* @param addX the amount to add to the X component
* @param addY the amount to add to the Y component
* @return the (modified) current instance (for chaining)
*/
public Vector2f addLocal(float addX, float addY) {
x += addX;
y += addY;
return this;
}
/**
* Adds a specified vector and returns the sum in a 3rd vector. If the
* argument is null, null is returned. Either way, the current instance is
* unaffected unless it's {@code result}.
*
* @param vec the vector to add (unaffected unless it's {@code result}) or
* null for none
* @param result storage for the sum, or null for a new Vector2f
* @return the sum (either {@code result} or a new Vector2f)
*/
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;
}
/**
* Returns the dot (or inner) product with the argument. If the argument is
* null, 0 is returned. Either way, the current instance is unaffected.
*
* @param vec the vector to multiply (unaffected) or null for none
* @return the product or 0
*/
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;
}
/**
* Calculates a cross product with the argument and returns the product as a
* new instance. The current instance is unaffected.
*
* @param v the right factor (not null, unaffected)
* @return {@code this} cross {@code v} (a new Vector3f)
*/
public Vector3f cross(Vector2f v) {
return new Vector3f(0, 0, determinant(v));
}
/**
* Returns the Z component of the cross product with the argument. The
* current instance is unaffected.
*
* @param v the right factor (not null, unaffected)
* @return the Z component of {@code this} cross {@code v}
*/
public float determinant(Vector2f v) {
return (x * v.y) - (y * v.x);
}
/**
* Interpolates linearly between the current instance and the specified
* vector, returning the (modified) current instance.
*
*
this = (1 - changeAmount) * this + changeAmount * finalVec
*
* @param finalVec the desired value when changeAmount=1 (not null,
* unaffected unless it's {@code this})
* @param changeAmount the fractional change amount
* @return the (modified) current instance (for chaining)
*/
public Vector2f interpolateLocal(Vector2f finalVec, float changeAmount) {
this.x = (1 - changeAmount) * this.x + changeAmount * finalVec.x;
this.y = (1 - changeAmount) * this.y + changeAmount * finalVec.y;
return this;
}
/**
* Interpolates linearly between the specified beginning and final vectors,
* returning the (modified) current instance.
*
*
this = (1 - changeAmount) * beginVec + changeAmount * finalVec
*
* @param beginVec the desired value when changeAmount=0 (not null,
* unaffected unless it's {@code this})
* @param finalVec the desired value when changeAmount=1 (not null,
* unaffected unless it's {@code this})
* @param changeAmount the fractional change amount
* @return the (modified) current instance (for chaining)
*/
public Vector2f interpolateLocal(Vector2f beginVec, Vector2f finalVec,
float changeAmount) {
this.x = (1 - changeAmount) * beginVec.x + changeAmount * finalVec.x;
this.y = (1 - changeAmount) * beginVec.y + changeAmount * finalVec.y;
return this;
}
/**
* Tests whether the argument is a valid vector, returning false if it's
* null or if any component is NaN or infinite.
*
* @param vector the vector to test (unaffected)
* @return true if non-null and finite, otherwise false
*/
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;
}
/**
* Returns the length (or magnitude). The current instance is unaffected.
*
* @return the root-sum of the squared components (not negative)
*/
public float length() {
return FastMath.sqrt(lengthSquared());
}
/**
* Returns the square of the length. The current instance is unaffected.
*
* @return the sum of the squared components (not negative)
*/
public float lengthSquared() {
return x * x + y * y;
}
/**
* Returns the square of the distance between the current instance and the
* argument. The current instance is unaffected.
*
* @param v the vector to compare (not null, unaffected)
* @return the square of the Euclidean distance (not negative)
*/
public float distanceSquared(Vector2f v) {
double dx = x - v.x;
double dy = y - v.y;
return (float) (dx * dx + dy * dy);
}
/**
* Returns the square of the distance between the current instance and a
* vector with the specified components. The current instance is unaffected.
*
* @param otherX the X component of the vector to compare
* @param otherY the Y component of the vector to compare
* @return the square of the Euclidean distance (not negative)
*/
public float distanceSquared(float otherX, float otherY) {
double dx = x - otherX;
double dy = y - otherY;
return (float) (dx * dx + dy * dy);
}
/**
* Returns the distance between the current instance and the argument. The
* current instance is unaffected.
*
* @param v the vector to compare (not null, unaffected)
* @return the Euclidean distance (not negative)
*/
public float distance(Vector2f v) {
return FastMath.sqrt(distanceSquared(v));
}
/**
* Multiplies with the scalar argument and returns the product as a new
* instance. The current instance is unaffected.
*
* @param scalar the scaling factor
* @return a new {@code Vector2f}
*/
public Vector2f mult(float scalar) {
return new Vector2f(x * scalar, y * scalar);
}
/**
* Multiplies by the scalar argument and returns the (modified) current
* instance.
*
* @param scalar the scaling factor
* @return the (modified) current instance (for chaining)
*/
public Vector2f multLocal(float scalar) {
x *= scalar;
y *= scalar;
return this;
}
/**
* Multiplies component-wise by the argument and returns the (modified)
* current instance. If the argument is null, null is returned.
*
* @param vec the scale vector (unaffected unless it's {@code this}) or
* null for none
* @return the (modified) current instance (for chaining) or null
*/
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 with the specified scalar and stores the product in the
* specified vector. The current instance is unaffected.
*
* @param scalar the scaling factor
* @param product storage for the product, or null for a new Vector2f
* @return either {@code product} or a new Vector2f
*/
public Vector2f mult(float scalar, Vector2f product) {
if (null == product) {
product = new Vector2f();
}
product.x = x * scalar;
product.y = y * scalar;
return product;
}
/**
* Divides by the scalar argument and returns the quotient as a new
* instance. The current instance is unaffected.
*
* @param scalar the divisor
* @return a new {@code Vector2f}
*/
public Vector2f divide(float scalar) {
return new Vector2f(x / scalar, y / scalar);
}
/**
* Divides the vector by the scalar argument and returns the (modified)
* current instance.
*
* @param scalar the divisor
* @return the (modified) current instance (for chaining)
*/
public Vector2f divideLocal(float scalar) {
x /= scalar;
y /= scalar;
return this;
}
/**
* Returns the negative of the vector. The current instance is unaffected.
*
* @return a new Vector2f
*/
public Vector2f negate() {
return new Vector2f(-x, -y);
}
/**
* Negates both components and returns the (modified) current instance.
*
* @return the (modified) current instance (for chaining)
*/
public Vector2f negateLocal() {
x = -x;
y = -y;
return this;
}
/**
* Subtracts the argument and returns the difference as a new instance. The
* current instance is unaffected.
*
* @param vec the vector to subtract (not null, unaffected)
* @return a new Vector2f
*/
public Vector2f subtract(Vector2f vec) {
return subtract(vec, null);
}
/**
* Subtracts the specified vector and returns the difference in a 3rd
* vector. The current instance is unaffected unless it's {@code store}.
*
*
It is safe for {@code vec} and {@code store} to be the same object.
*
* @param vec the vector to subtract (not null, unaffected unless it's
* {@code store})
* @param store storage for the difference, or null for a new Vector2f
* @return either {@code store} or a new Vector2f
*/
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;
}
/**
* Subtracts the specified amounts from the vector's components and returns
* the difference as a new instance. The current instance is unaffected.
*
* @param valX the amount to subtract from the X component
* @param valY the amount to subtract from the Y component
* @return a new Vector2f
*/
public Vector2f subtract(float valX, float valY) {
return new Vector2f(x - valX, y - valY);
}
/**
* Subtracts the argument and returns the (modified) current instance. If
* the argument is null, null is returned.
*
* @param vec the vector to subtract (unaffected unless it's {@code this})
* or null for none
* @return the (modified) current instance or null
*/
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;
}
/**
* Subtracts the specified amounts from the vector's components and returns
* the (modified) current instance.
*
* @param valX the amount to subtract from the X component
* @param valY the amount to subtract from the Y component
* @return the (modified) current instance (for chaining)
*/
public Vector2f subtractLocal(float valX, float valY) {
x -= valX;
y -= valY;
return this;
}
/**
* Normalizes the vector to length=1 and returns the result as a new
* instance. If the vector has length=0, a clone is returned. Either way,
* the current instance is unaffected.
*
* @return a new Vector2f
*/
public Vector2f normalize() {
float length = length();
if (length != 0) {
return divide(length);
}
return divide(1);
}
/**
* Normalizes the vector to length=1 and returns the (modified) current
* instance. If the vector has length=0, it's unchanged.
*
* @return the (modified) current instance (for chaining)
*/
public Vector2f normalizeLocal() {
float length = length();
if (length != 0) {
return divideLocal(length);
}
return divideLocal(1);
}
/**
* Returns the unsigned angle between the current instance and the argument,
* provided both vectors have length=1. If {@code otherVector} is null, Pi/2
* is returned. The current instance is unaffected.
*
* @param otherVector the unit vector to compare (unaffected) or null for
* none
* @return the angle in radians (not negative)
*/
public float smallestAngleBetween(Vector2f otherVector) {
float dotProduct = dot(otherVector);
float angle = FastMath.acos(dotProduct);
return angle;
}
/**
* Returns the signed angle between the current instance and the argument.
* The current instance is unaffected.
*
* @param otherVector the vector to compare (not null, unaffected)
* @return the angle in radians, measured counter-clockwise from {@code
* this} to {@code otherVector} (≥-2*Pi, ≤2*Pi)
*/
public float angleBetween(Vector2f otherVector) {
float angle = FastMath.atan2(otherVector.y, otherVector.x)
- FastMath.atan2(y, x);
return angle;
}
/**
* Returns the X component. The vector is unaffected.
*
* @return the value of the {@link #x} component
*/
public float getX() {
return x;
}
/**
* Sets the X component.
*
* @param x the desired value
* @return the (modified) current instance (for chaining)
*/
public Vector2f setX(float x) {
this.x = x;
return this;
}
/**
* Returns the Y component. The vector is unaffected.
*
* @return the value of the {@link #y} component
*/
public float getY() {
return y;
}
/**
* Sets the Y component.
*
* @param y the desired value
* @return the (modified) current instance (for chaining)
*/
public Vector2f setY(float y) {
this.y = y;
return this;
}
/**
* Returns the angle of the vector in polar coordinates. The current
* instance is unaffected.
*
* @return the polar angle in radians, measured counter-clockwise from the
* +X axis (≥-Pi, ≤Pi)
*/
public float getAngle() {
return FastMath.atan2(y, x);
}
/**
* Sets both components to zero.
*
* @return the (modified) current instance (for chaining)
*/
public Vector2f zero() {
x = y = 0;
return this;
}
/**
* Returns a hash code. If two vectors are logically equivalent, they will
* return the same hash code. The current instance is unaffected.
*
* @return the hash code value
*/
@Override
public int hashCode() {
int hash = 37;
hash += 37 * hash + Float.floatToIntBits(x);
hash += 37 * hash + Float.floatToIntBits(y);
return hash;
}
/**
* Creates a copy. The current instance is unaffected.
*
* @return a new instance, equivalent to the current one
*/
@Override
public Vector2f clone() {
try {
return (Vector2f) super.clone();
} catch (CloneNotSupportedException e) {
throw new AssertionError(); // can not happen
}
}
/**
* Copies the vector to the array argument. The current instance is
* unaffected.
*
* @param floats storage for the components (must have length≥2) or null
* for a new float[2]
* @return an array containing the X and Y components in that order (either
* {@code floats} or a new float[2])
*/
public float[] toArray(float[] floats) {
if (floats == null) {
floats = new float[2];
}
floats[0] = x;
floats[1] = y;
return floats;
}
/**
* Tests for exact equality with the argument, distinguishing -0 from 0. If
* {@code o} is null, false is returned. Either way, the current instance is
* unaffected.
*
* @param o the object to compare (unaffected) or null for none
* @return true if equal, otherwise false
*/
@Override
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;
}
/**
* Tests for approximate equality with the specified vector, using the
* specified tolerance. If {@code other} is null, false is returned. Either
* way, the current instance is unaffected.
*
* @param other the vector to compare (unaffected) or null for none
* @param epsilon the tolerance for each component
* @return true if both components are within tolerance, otherwise false
*/
public boolean isSimilar(Vector2f other, float epsilon) {
if (other == null) {
return false;
}
if (Float.compare(Math.abs(other.x - x), epsilon) > 0) {
return false;
}
if (Float.compare(Math.abs(other.y - y), epsilon) > 0) {
return false;
}
return true;
}
/**
* Returns a string representation of the vector. The current instance is
* unaffected. The format is:
*
*
(XX.XXXX, YY.YYYY)
*
* @return the string representation
*/
@Override
public String toString() {
return "(" + x + ", " + y + ")";
}
/**
* Sets the vector from an {@code ObjectInput} object.
*
*
Used with serialization. Shouldn't be invoked directly by application
* code.
*
* @param in the object to read from (not null)
* @throws IOException if the ObjectInput cannot read a float
* @throws ClassNotFoundException never
* @see java.io.Externalizable
*/
public void readExternal(ObjectInput in) throws IOException,
ClassNotFoundException {
x = in.readFloat();
y = in.readFloat();
}
/**
* Writes the vector to an {@code ObjectOutput} object. The current instance
* is unaffected.
*
*
Used with serialization. Shouldn't be invoked directly by application
* code.
*
* @param out the object to write to (not null)
* @throws IOException if the ObjectOuput cannot write a float
* @see java.io.Externalizable
*/
public void writeExternal(ObjectOutput out) throws IOException {
out.writeFloat(x);
out.writeFloat(y);
}
/**
* Serializes the vector to the specified exporter, for example when saving
* to a J3O file. The current instance is unaffected.
*
* @param e the exporter to use (not null)
* @throws IOException from the exporter
*/
@Override
public void write(JmeExporter e) throws IOException {
OutputCapsule capsule = e.getCapsule(this);
capsule.write(x, "x", 0);
capsule.write(y, "y", 0);
}
/**
* De-serializes the vector from the specified importer, for example
* when loading from a J3O file.
*
* @param importer the importer to use (not null)
* @throws IOException from the importer
*/
@Override
public void read(JmeImporter importer) throws IOException {
InputCapsule capsule = importer.getCapsule(this);
x = capsule.readFloat("x", 0);
y = capsule.readFloat("y", 0);
}
/**
* Rotates the vector around (0,0) by the specified angle.
*
* @param angle the rotation angle (in radians)
* @param cw true to rotate clockwise, false to rotate counter-clockwise
*/
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;
}
}