content: /**
   * This file is part of Aion-Lightning <aion-lightning.org>.
   *
   *  Aion-Lightning 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
   *  (at your option) any later version.
   *
   *  Aion-Lightning 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 Aion-Lightning.
   *  If not, see <http://www.gnu.org/licenses/>.
   */
  package com.aionemu.gameserver.geoEngine.math;
  
  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 Cloneable {
  
  	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 interpolate(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 interpolate(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 v
  	 *            the second vector to determine the distance squared.
  	 * @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>,&nbsp; <code>y</code>) to polar
  	 * coordinates (r,&nbsp;<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.
  	 */
  	@Override
  	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
  	 */
  	@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;
  	}
  
  	/**
  	 * <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.
  	 */
  	@Override
  	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 Class<? extends Vector2f> getClassTag() {
  		return this.getClass();
  	}
  
  	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;
  	}
  }
  