1 package edu.berkeley.qfat.geom;
2 import javax.media.opengl.*;
3 import javax.media.opengl.glu.*;
5 /** vector in 3-space; immutable */
6 public final class Vec {
7 public final float x, y, z;
8 public Vec(double x, double y, double z) { this((float)x, (float)y, (float)z); }
9 public Vec(float x, float y, float z) { this.x = x; this.y = y; this.z = z; }
10 public Vec(Point p1, Point p2) { this(p2.x-p1.x, p2.y-p1.y, p2.z-p1.z); }
11 public Vec cross(Vec v) { return new Vec(y*v.z-z*v.y, z*v.x-x*v.z, x*v.y-y*v.x); }
12 public Vec plus(Vec v) { return new Vec(x+v.x, y+v.y, z+v.z); }
13 public Point plus(Point p) { return p.plus(this); }
14 public Vec minus(Vec v) { return new Vec(x-v.x, y-v.y, z-v.z); }
15 public Vec norm() { return mag()==0 ? this : div(mag()); }
16 public float mag() { return (float)Math.sqrt(x*x+y*y+z*z); }
17 public float dot(Vec v) { return x*v.x + y*v.y + z*v.z; }
18 public Vec times(float mag) { return new Vec(x*mag, y*mag, z*mag); }
19 public Vec div(float mag) { return new Vec(x/mag, y/mag, z/mag); }
20 public String toString() { return "<"+x+","+y+","+z+">"; }
21 public void glNormal(GL gl) { gl.glNormal3f(x, y, z); }
23 /** fundamental error quadric for the plane with this normal passing through p */
24 public Matrix fundamentalQuadric(Point p) {
26 if (mag() != 1) n = norm();
30 float d = (-a * p.x) + (-b * p.y) + (-c * p.z);
31 return new Matrix(a*a, a*b, a*c, a*d,