ini/trakem2/utils/Vector3D.java

   1 /** Adapted by Albert Cardona from the ArcBall C code in the Graphics Gems IV, 1993. */
   2 package ini.trakem2.utils;
   3
   4 public class Vector3D {
   5
   6         public double x, y, z;
   7
   8         public Vector3D(double x, double y, double z) {
   9                 this.x = x;
  10                 this.y = y;
  11                 this.z = z;
  12         }
  13
  14         public Vector3D() { this(0,0,0); }
  15
  16         public Vector3D(Vector3D v) { this(v.x, v.y, v.z); }
  17
  18         public Object clone() { return new Vector3D(x, y, z); }
  19
  20         public String toString() { return "Vector3D(" + x + ", " + y + ", " + z + ")"; }
  21
  22         public double length() { return Math.sqrt(x*x + y*y + z*z); }
  23
  24         /** Does nothing if the length is zero. */
  25         public void normalize() {
  26                 double vlen = length();
  27                 if (vlen != 0.0) {
  28                         x /= vlen;
  29                         y /= vlen;
  30                         z /= vlen;
  31                 }
  32         }
  33
  34         public void scale(double s) {
  35                 x *= s;
  36                 y *= s;
  37                 z *= s;
  38         }
  39
  40         /** Substracts the given vector to this one. */
  41         public void substract(Vector3D v) {
  42                 x -= v.x;
  43                 y -= v.y;
  44                 z -= v.z;
  45         }
  46
  47         public void add(Vector3D v) {
  48                 x += v.x;
  49                 y += v.y;
  50                 z += v.z;
  51         }
  52
  53         public void negate() {
  54                 x = -x;
  55                 y = -y;
  56                 z = -z;
  57         }
  58
  59         public double dotProduct(Vector3D v) {
  60                 return x*v.x + y*v.y + z*v.z;
  61         }
  62
  63         public Vector3D crossProduct(Vector3D v) {
  64                 return new Vector3D(y*v.z - z*v.y, z*v.x - x*v.z, x*v.y - y*v.x);
  65         }
  66
  67         /** @return half arc between vector and v */
  68         public Vector3D bisect(Vector3D v) {
  69                 Vector3D r = new Vector3D(x + v.x, y + v.y, z + v.z);
  70                 double length = r.length();
  71                 if (length < 1.0e-7) {
  72                         r.set(0, 0, 1);
  73                 } else {
  74                         r.scale(1/length);
  75                 }
  76                 return r;
  77         }
  78
  79         public void set(double x, double y, double z) {
  80                 this.x = x;
  81                 this.y = y;
  82                 this.z = z;
  83         }
  84
  85         public Vector3D rotateAroundAxis(Vector3D axis, double sin, double cos) {
  86                 // obtain a normalized axis first
  87                 Vector3D r = new Vector3D(axis);
  88                 r.normalize();
  89                 return new Vector3D((cos + (1-cos) * r.x * r.x) * x + ((1-cos) * r.x * r.y - r.z * sin) * y + ((1-cos) * r.x * r.z + r.y * sin) * z,
  90                            ((1-cos) * r.x * r.y + r.z * sin) * x + (cos + (1-cos) * r.y * r.y) * y + ((1-cos) * r.y * r.z - r.x * sin) * z,
  91                            ((1-cos) * r.y * r.z - r.y * sin) * x + ((1-cos) * r.y * r.z + r.x * sin) * y + (cos + (1-cos) * r.z * r.z) * z);
  92         }
  93
  94 }