/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef ThreeDPoint_h_
#define ThreeDPoint_h_

#include <cmath>
#include <algorithm>

namespace mozilla {

namespace dom {

struct ThreeDPoint final
{
  ThreeDPoint()
    : x(0.)
    , y(0.)
    , z(0.)
  {
  }
  ThreeDPoint(double aX, double aY, double aZ)
    : x(aX)
    , y(aY)
    , z(aZ)
  {
  }

  double Magnitude() const
  {
    return sqrt(x * x + y * y + z * z);
  }

  void Normalize()
  {
    // Zero vectors cannot be normalized. For our purpose, normalizing a zero
    // vector results in a zero vector.
    if (IsZero()) {
      return;
    }
    // Normalize with the maximum norm first to avoid overflow and underflow.
    double invMax = 1 / MaxNorm();
    x *= invMax;
    y *= invMax;
    z *= invMax;

    double invDistance = 1 / Magnitude();
    x *= invDistance;
    y *= invDistance;
    z *= invDistance;
  }

  ThreeDPoint CrossProduct(const ThreeDPoint& rhs) const
  {
    return ThreeDPoint(y * rhs.z - z * rhs.y,
                       z * rhs.x - x * rhs.z,
                       x * rhs.y - y * rhs.x);
  }

  double DotProduct(const ThreeDPoint& rhs)
  {
    return x * rhs.x + y * rhs.y + z * rhs.z;
  }

  bool IsZero() const
  {
    return x == 0 && y == 0 && z == 0;
  }

  // For comparing two vectors of close to unit magnitude.
  bool FuzzyEqual(const ThreeDPoint& other);

  double x, y, z;

private:
  double MaxNorm() const
  {
    return std::max(fabs(x), std::max(fabs(y), fabs(z)));
  }
};

ThreeDPoint operator-(const ThreeDPoint& lhs, const ThreeDPoint& rhs);
ThreeDPoint operator*(const ThreeDPoint& lhs, const ThreeDPoint& rhs);
ThreeDPoint operator*(const ThreeDPoint& lhs, const double rhs);
bool operator==(const ThreeDPoint& lhs, const ThreeDPoint& rhs);

} // namespace dom
} // namespace mozilla

#endif

