ini/trakem2/utils/Vector3.java

   1 /**
   2  * FROM : package org.freehep.graphics3d;
   3  *
   4  * Keeps a 3 dimensional vector.
   5  * <p>
   6  * Original ArcBall C code from Ken Shoemake, Graphics Gems IV, 1993.
   7  *
   8  * @author Mark Donszelmann
   9  * @version $Id: Vector3.java,v 1.2 2002/06/12 23:15:15 duns Exp $
  10  */
  11
  12
  13
  14 package ini.trakem2.utils;
  15
  16 public class Vector3 {
  17
  18         public double x, y, z;
  19
  20         /**
  21          * creates vector from x,y,z
  22          */
  23         public Vector3(double x, double y, double z) {
  24                 this.x = x;
  25                 this.y = y;
  26                 this.z = z;
  27         }
  28
  29         /**
  30          * creates null vector
  31          */
  32         public Vector3() {
  33                 this(0,0,0);
  34         }
  35
  36         /**
  37          * creates vector from v
  38          */
  39         public Vector3(Vector3 v) {
  40                 this(v.x, v.y, v.z);
  41         }
  42
  43         /**
  44          * @return string representation of vector
  45          */
  46
  47         /*public String toString() {
  48                 return "["+x+", "+y+", "+z+"]";
  49 }*/
  50
  51         /**
  52          * @return length
  53          */
  54         public double length() {
  55                 return Math.sqrt(x*x + y*y + z*z);
  56         }
  57
  58         /**
  59          * @return normal vector , or null if length is 0
  60          */
  61
  62
  63         public Vector3 normalize(Vector3 r) {
  64                 if (r == null) r = new Vector3();
  65                 double vlen = length();
  66                 if (vlen != 0.0) {
  67                         return r.set(x/vlen, y/vlen, z/vlen);
  68                 }
  69                 return null;
  70         }
  71
  72
  73         /**
  74          * @return vector scaled by s
  75          */
  76         public Vector3 scale(double s, Vector3 r) {
  77                 if (r == null) r = new Vector3();
  78                 return r.set(s*x, s*y, s*z);
  79         }
  80
  81         /**
  82          * @return difference between vector and s
  83          */
  84         /*public Vector3 sub(Vector3 s, Vector3 r) {
  85                 if (r == null) r = new Vector3();
  86                 return r.set(x - s.x, y - s.y, z - s.z);
  87 }*/
  88
  89         /**
  90          * @return sum of vector and v
  91          */
  92         public Vector3 add(Vector3 v, Vector3 r) {
  93                 if (r == null) r = new Vector3();
  94                 return r.set(x + v.x, y + v.y, z + v.z);
  95         }
  96
  97         /**
  98          * @return the negation of vector
  99          */
 100         /*public Vector3 negate(Vector3 r) {
 101                 if (r == null) r = new Vector3();
 102                 return r.set(-x, -y, -z);
 103 }*/
 104
 105         /**
 106          * @return dot product of vector and v
 107          */
 108         /*public double dot(Vector3 v) {
 109                 return x*v.x + y*v.y + z*v.z;
 110         */
 111
 112
 113         /**
 114          * @return cross produc of vector x v
 115          */
 116         /*public Vector3 cross(Vector3 v, Vector3 r) {
 117                 if (r == null) r = new Vector3();
 118                 return r.set(y*v.z-z*v.y, z*v.x-x*v.z, x*v.y-y*v.x);
 119 }*/
 120
 121         /**
 122          * @return half arc between vector and v
 123          */
 124         /*public Vector3 bisect(Vector3 v, Vector3 r) {
 125                 if (r == null) r = new Vector3();
 126                 add(v, r);
 127                 double length = r.length();
 128                 return (length < 1.0e-7) ? r.set(0, 0, 1) : r.scale(1/length, r);
 129 }*/
 130
 131         /**
 132          * @return the vector set to x,y,z
 133          */
 134         public Vector3 set(double x, double y, double z) {
 135                 this.x = x;
 136                 this.y = y;
 137                 this.z = z;
 138                 return this;
 139         }
 140
 141 }  // End of class Vector3