#include <cmath>   //for atan2
#include "point.h"
using namespace std;

//Rotate this point around the X axis.

point& point::xrot(double theta)
{
	if (y != 0.0 || z != 0.0) {	//if this point is not on the X axis,
		const double r = sqrt(y * y + z * z);
		theta += atan2(z, y);
		y = r * cos(theta);
		z = r * sin(theta);
	}
	return *this;
}

//Rotate this point around the Y axis.

point& point::yrot(double theta)
{
	if (z != 0.0 || x != 0.0) {	//if this point is not on the Y axis,
		const double r = sqrt(z * z + x * x);
		theta += atan2(x, z);
		z = r * cos(theta);
		x = r * sin(theta);
	}
	return *this;
}

//Rotate this point around the Z axis.

point& point::zrot(double theta)
{
	if (x != 0.0 || y != 0.0) {	//if this point is not on the Z axis,
		const double r = sqrt(x * x + y * y);
		theta += atan2(y, x);
		x = r * cos(theta);
		y = r * sin(theta);
	}
	return *this;
}