src/vector.cpp

   1 // Copyright (C) 2006 Erik Dahlberg
   2 //
   3 // This file is part of LSystem3d.
   4 //
   5 // LSystem3D is free software; you can redistribute it and/or
   6 // modify it under the terms of the GNU General Public License
   7 // as published by the Free Software Foundation; either version 2
   8 // of the License, or (at your option) any later version.
   9 //
  10 // LSystem3D is distributed in the hope that it will be useful,
  11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 // GNU General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with LSystem3D; if not, write to the Free Software
  17 // Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18
  19
  20
  21
  22 #include <cmath>
  23
  24 #include "vector.h"
  25
  26
  27
  28 /**
  29  * Constructor
  30  * @param x the x-coordinate
  31  * @param y the y-coordinate
  32  * @param z the z-coordinate
  33  */
  34 Vector::Vector(double x, double y, double z)
  35 {
  36     setXYZ(x, y, z);
  37 }
  38
  39
  40
  41 /**
  42  * Destructor
  43  */
  44 Vector::~Vector()
  45 {
  46 }
  47
  48
  49
  50 /**
  51  * Rotate around another vector
  52  * @param angle rotation angle
  53  * @param vector arbitrary vector to rotate around
  54  */
  55 void Vector::rotate(double angle, Vector vector)
  56 {
  57     double c = cos(angle);
  58     double s = sin(angle);
  59
  60     double x =
  61     _x * (vector._x * vector._x * (1.0 - c) + c) +
  62     _y * (vector._x * vector._y * (1.0 - c) + vector._z * s) +
  63     _z * (vector._x * vector._z * (1.0 - c) - vector._y * s);
  64
  65     double y =
  66     _x * (vector._y * vector._x * (1.0 - c) - vector._z * s) +
  67     _y * (vector._y * vector._y * (1.0 - c) + c) +
  68     _z * (vector._y * vector._z * (1.0 - c) + vector._x * s);
  69
  70     double z =
  71     _x * (vector._z * vector._x * (1.0 - c) + vector._y * s) +
  72     _y * (vector._z * vector._y * (1.0 - c) - vector._x * s) +
  73     _z * (vector._z * vector._z * (1.0 - c) + c);
  74
  75     _x = x;
  76     _y = y;
  77     _z = z;
  78
  79     // TODO: call it from outside?
  80     normalize();
  81 }
  82
  83
  84
  85 /**
  86  * Normalize vector
  87  */
  88 void Vector::normalize()
  89 {
  90     double length = sqrt(_x * _x + _y * _y + _z * _z);
  91
  92     if (length != 0)
  93     {
  94         _x /= length;
  95         _y /= length;
  96         _z /= length;
  97     }
  98 }
  99
 100
 101
 102 /**
 103  * Get scalar product of the vectors
 104  * @param vector arbitrary vector
 105  * @return the scalar product
 106  */
 107 double Vector::getScalarProduct(Vector vector)
 108 {
 109     double scalarProduct = getX() * vector.getX() +
 110                            getY() * vector.getY() +
 111                            getZ() * vector.getZ();
 112
 113     return scalarProduct;
 114 }
 115
 116
 117
 118 /**
 119  * Get cross product of the vectors
 120  * @param vector arbitrary vector
 121  * @return the cross product
 122  */
 123 Vector Vector::getCrossProduct(Vector vector)
 124 {
 125     Vector crossProduct(getY() * vector.getZ() - getZ() * vector.getY(),
 126                         getZ() * vector.getX() - getX() * vector.getZ(),
 127                         getX() * vector.getY() - getY() * vector.getX());
 128
 129     return crossProduct;
 130 }
 131
 132
 133
 134 /**
 135  * Get angle between the vectors
 136  * @param vector the second (normalized) vector
 137  * @return the angle, in degrees
 138  */
 139 double Vector::getAngle(Vector vector)
 140 {
 141     double scalarProduct = getScalarProduct(vector);
 142     double angle = (acos(scalarProduct) / (M_PIl * 2.0)) * 360.0;
 143
 144     return angle;
 145 }