point3d.h

/* This proram is part of Qt examples.
   Copyright 2015-2022 by Chun-Ming Su
   E-Mail: sokunmin@gmail.com
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#ifndef POINT3D_H
#define POINT3D_H

#include "math.h"

#include <qglobal.h>

struct Point3d
{
    float x, y, z;

    Point3d()
        : x(0)
        , y(0)
        , z(0)
    {
    }

    Point3d(float x_, float y_, float z_)
        : x(x_)
        , y(y_)
        , z(z_)
    {
    }

    Point3d operator+(const Point3d &p) const
    {
        return Point3d(*this) += p;
    }

    Point3d operator-(const Point3d &p) const
    {
        return Point3d(*this) -= p;
    }

    Point3d operator*(float f) const
    {
        return Point3d(*this) *= f;
    }


    Point3d &operator+=(const Point3d &p)
    {
        x += p.x;
        y += p.y;
        z += p.z;
        return *this;
    }

    Point3d &operator-=(const Point3d &p)
    {
        x -= p.x;
        y -= p.y;
        z -= p.z;
        return *this;
    }

    Point3d &operator*=(float f)
    {
        x *= f;
        y *= f;
        z *= f;
        return *this;
    }

    Point3d normalize() const
    {
        float r = 1. / sqrt(x * x + y * y + z * z);
        return Point3d(x * r, y * r, z * r);
    }
    float &operator[](unsigned int index) {
        Q_ASSERT(index < 3);
        return (&x)[index];
    }

    const float &operator[](unsigned int index) const {
        Q_ASSERT(index < 3);
        return (&x)[index];
    }
};

inline float dot(const Point3d &a, const Point3d &b)
{
    return a.x * b.x + a.y * b.y + a.z * b.z;
}

inline Point3d cross(const Point3d &a, const Point3d &b)
{
    return Point3d(a.y * b.z - a.z * b.y,
                   a.z * b.x - a.x * b.z,
                   a.x * b.y - a.y * b.x);
}

#endif