/*
* Copyright 2009 by Kevin Day.
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (the "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999-2008 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000-2008 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library 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 Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* http://www.lowagie.com/iText/
*/
package com.lowagie.text.pdf.parser;
/**
* Represents a vector (i.e. a point in space). This class is completely
* unrelated to the {@link java.util.Vector} class in the standard JRE.
* <br><br>
* For many PDF related operations, the z coordinate is specified as 1
* This is to support the coordinate transformation calculations. If it
* helps, just think of all PDF drawing operations as occurring in a single plane
* with z=1.
*/
public class Vector {
/** index of the X coordinate */
public static final int I1 = 0;
/** index of the Y coordinate */
public static final int I2 = 1;
/** index of the Z coordinate */
public static final int I3 = 2;
/** the values inside the vector */
private final float[] vals = new float[]{
0,0,0
};
/**
* Creates a new Vector
* @param x the X coordinate
* @param y the Y coordinate
* @param z the Z coordinate
*/
public Vector(float x, float y, float z) {
vals[I1] = x;
vals[I2] = y;
vals[I3] = z;
}
/**
* Gets the value from a coordinate of the vector
* @param index the index of the value to get (I1, I2 or I3)
* @return
*/
public float get(int index){
return vals[index];
}
/**
* Computes the cross product of this vector and the specified matrix
* @param by the matrix to cross this vector with
* @return the result of the cross product
*/
public Vector cross(Matrix by){
float x = vals[I1]*by.get(Matrix.I11) + vals[I2]*by.get(Matrix.I21) + vals[I3]*by.get(Matrix.I31);
float y = vals[I1]*by.get(Matrix.I12) + vals[I2]*by.get(Matrix.I22) + vals[I3]*by.get(Matrix.I32);
float z = vals[I1]*by.get(Matrix.I13) + vals[I2]*by.get(Matrix.I23) + vals[I3]*by.get(Matrix.I33);
return new Vector(x, y, z);
}
/**
* Computes the difference between this vector and the specified vector
* @param v the vector to subtract from this one
* @return the results of the subtraction
*/
public Vector subtract(Vector v){
float x = vals[I1] - v.vals[I1];
float y = vals[I2] - v.vals[I2];
float z = vals[I3] - v.vals[I3];
return new Vector(x, y, z);
}
/**
* Computes the cross product of this vector and the specified vector
* @param with the vector to cross this vector with
* @return the cross product
*/
public Vector cross(Vector with){
float x = vals[I2]*with.vals[I3] - vals[I3]*with.vals[I2];
float y = vals[I3]*with.vals[I1] - vals[I1]*with.vals[I3];
float z = vals[I1]*with.vals[I2] - vals[I2]*with.vals[I1];
return new Vector(x, y, z);
}
/**
* Computes the dot product of this vector with the specified vector
* @param with the vector to dot product this vector with
* @return the dot product
*/
public float dot(Vector with){
return vals[I1]*with.vals[I1] + vals[I2]*with.vals[I2] + vals[I3]*with.vals[I3];
}
/**
* Computes the length of this vector
*
* <b>Note:</b> If you are working with raw vectors from PDF, be careful -
* the Z axis will generally be set to 1. If you want to compute the
* length of a vector, subtract it from the origin first (this will set
* the Z axis to 0).
*
* For example:
* <code>aVector.subtract(originVector).length();</code>
*
* @return the length of this vector
*/
public float length(){
return (float)Math.sqrt(lengthSquared());
}
/**
* Computes the length squared of this vector.
*
* The square of the length is less expensive to compute, and is often
* useful without taking the square root.
* <br><br>
* <b>Note:</b> See the important note under {@link Vector#length()}
*
* @return the square of the length of the vector
*/
public float lengthSquared(){
return vals[I1]*vals[I1] + vals[I2]*vals[I2] + vals[I3]*vals[I3];
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
return vals[I1]+","+vals[I2]+","+vals[I3];
}
}