Sphere-Klasse Raytracing

//SPHERE.H
#ifndef SPHERE_H
#define SPHERE_H

class RenderObject;

class Sphere : public RenderObject
{
private:
public:
    Sphere(Renderer& newRenderer);
    Sphere(Renderer& newRenderer, Material& newMaterial);
    int testRay(const sf::Vector3f& origin, const sf::Vector3f& direction, sf::Vector3f& hitPosition, sf::Vector2f& UVCoordinates);
    const sf::Vector3f& getNormal(const sf::Vector3f& point);
    const sf::Vector3f& getNormal();
};

#endif //SPHERE_H

//SPHERE.CPP
#include <SFML\Graphics.hpp>
#include <math.h>
#include <C:\Users\Laurin\Documents\Visual Studio 2012\Projects\Raytracing\Raytracing\renderer.h>
#include <C:\Users\Laurin\Documents\Visual Studio 2012\Projects\Raytracing\Raytracing\renderObject.h>
#include <C:\Users\Laurin\Documents\Visual Studio 2012\Projects\Raytracing\Raytracing\util.h>
#include <C:\Users\Laurin\Documents\Visual Studio 2012\Projects\Raytracing\Raytracing\sphere.h>

Sphere::Sphere(Renderer& newRenderer)
    :RenderObject(newRenderer)
{
    renderer.addRenderObject(this);
}

Sphere::Sphere(Renderer& newRenderer, Material& newMaterial)
    :RenderObject(newRenderer, newMaterial)
{
    renderer.addRenderObject(this);
}

int Sphere::testRay(const sf::Vector3f& origin, const sf::Vector3f& direction, sf::Vector3f& hitPosition, sf::Vector2f& UVCoordinates)
{
    float factor = -dot((origin-transform.position), direction);
    sf::Vector3f x = origin + factor * direction;
    float xLength = length(x-transform.position);
    float distance = sqrt((transform.scale.x/2 * transform.scale.x/2) - (xLength * xLength));
    if(factor > distance)
    {
        hitPosition = origin + (factor - distance) * direction;
        sf::Vector2f UVs(0.0f, 0.0f);
        if(material.texture)
        {
            sf::Vector3f yAxis(0.0f, 1.0f, 0.0f);
            sf::Vector3f zAxis(0.0f, 0.0f, -1.0f);
            sf::Vector3f normal = getNormal(hitPosition);
            float phi = acos( -dot( yAxis, normal ));
            UVs.y = phi / 3.14f;

            float theta = (acos( dot( normal, zAxis) / sin( phi ))) / ( 2 * 3.14f);
            if ( dot(cross( yAxis, zAxis), normal ) > 0 )
            {
                UVs.x = theta;
            }
            else
            {
                UVs.x = 1 - theta;
            }
        }
        UVCoordinates = UVs;
        return 1;
    }
    else if(factor + distance > 0)
    {
        hitPosition = origin + (factor + distance) * direction;
        return -1;
    }
    else
    {
        return 0;
    }
}


const sf::Vector3f& Sphere::getNormal(const sf::Vector3f& point)
{
    sf::Vector3f normal = point-transform.position;
    return normalize(normal);
}

const sf::Vector3f& Sphere::getNormal()
{
    return sf::Vector3f(0.0f, 0.0f, 0.0f);
}