/*
 * gleem -- OpenGL Extremely Easy-To-Use Manipulators.
 * Copyright (C) 1998-2003 Kenneth B. Russell (kbrussel@alum.mit.edu)
 * See the file GLEEM-LICENSE.txt in the doc/ directory for licensing terms.
 */

package gleem.linalg;

/** 3-element double-precision vector */

public class Vec3d {
  private double x;
  private double y;
  private double z;

  public Vec3d() {}

  public Vec3d(Vec3d arg) {
    set(arg);
  }

  public Vec3d(double x, double y, double z) {
    set(x, y, z);
  }

  public Vec3d copy() {
    return new Vec3d(this);
  }

  /** Convert to single-precision */
  public Vec3f toFloat() {
    return new Vec3f((float) x, (float) y, (float) z);
  }

  public void set(Vec3d arg) {
    set(arg.x, arg.y, arg.z);
  }

  public void set(double x, double y, double z) {
    this.x = x;
    this.y = y;
    this.z = z;
  }

  /** Sets the ith component, 0 <= i < 3 */
  public void set(int i, double val) {
    switch (i) {
    case 0: x = val; break;
    case 1: y = val; break;
    case 2: z = val; break;
    default: throw new IndexOutOfBoundsException();
    }
  }

  /** Gets the ith component, 0 <= i < 3 */
  public double get(int i) {
    switch (i) {
    case 0: return x;
    case 1: return y;
    case 2: return z;
    default: throw new IndexOutOfBoundsException();
    }
  }

  public double x() { return x; }
  public double y() { return y; }
  public double z() { return z; }

  public void setX(double x) { this.x = x; }
  public void setY(double y) { this.y = y; }
  public void setZ(double z) { this.z = z; }

  public double dot(Vec3d arg) {
    return x * arg.x + y * arg.y + z * arg.z;
  }

  public double length() {
    return Math.sqrt(lengthSquared());
  }

  public double lengthSquared() {
    return this.dot(this);
  }

  public void normalize() {
    double len = length();
    if (len == 0.0) return;
    scale(1.0f / len);
  }

  /** Returns this * val; creates new vector */
  public Vec3d times(double val) {
    Vec3d tmp = new Vec3d(this);
    tmp.scale(val);
    return tmp;
  }

  /** this = this * val */
  public void scale(double val) {
    x *= val;
    y *= val;
    z *= val;
  }

  /** Returns this + arg; creates new vector */
  public Vec3d plus(Vec3d arg) {
    Vec3d tmp = new Vec3d();
    tmp.add(this, arg);
    return tmp;
  }

  /** this = this + b */
  public void add(Vec3d b) {
    add(this, b);
  }

  /** this = a + b */
  public void add(Vec3d a, Vec3d b) {
    x = a.x + b.x;
    y = a.y + b.y;
    z = a.z + b.z;
  }

  /** Returns this + s * arg; creates new vector */
  public Vec3d addScaled(double s, Vec3d arg) {
    Vec3d tmp = new Vec3d();
    tmp.addScaled(this, s, arg);
    return tmp;
  }

  /** this = a + s * b */
  public void addScaled(Vec3d a, double s, Vec3d b) {
    x = a.x + s * b.x;
    y = a.y + s * b.y;
    z = a.z + s * b.z;
  }

  /** Returns this - arg; creates new vector */
  public Vec3d minus(Vec3d arg) {
    Vec3d tmp = new Vec3d();
    tmp.sub(this, arg);
    return tmp;
  }

  /** this = this - b */
  public void sub(Vec3d b) {
    sub(this, b);
  }

  /** this = a - b */
  public void sub(Vec3d a, Vec3d b) {
    x = a.x - b.x;
    y = a.y - b.y;
    z = a.z - b.z;
  }

  /** Returns this cross arg; creates new vector */
  public Vec3d cross(Vec3d arg) {
    Vec3d tmp = new Vec3d();
    tmp.cross(this, arg);
    return tmp;
  }

  /** this = a cross b. NOTE: "this" must be a different vector than
      both a and b. */
  public void cross(Vec3d a, Vec3d b) {
    x = a.y * b.z - a.z * b.y;
    y = a.z * b.x - a.x * b.z;
    z = a.x * b.y - a.y * b.x;
  }

  public String toString() {
    return "(" + x + ", " + y + ", " + z + ")";
  }
}
