#include "Shape.h"
#include <algorithm>                /* sort() */
#include <functional>               /* binary_function */
#include <utility>
using namespace std;

Shape::Shape()
{
    m_transparency = 0.0;
    m_material = new Material(Material::white);
}

Shape::~Shape()
{
}

class IntersectionComparator : public std::binary_function<Shape::Intersection,
                                                           Shape::Intersection,
                                                           bool>
{
    public:
        IntersectionComparator(const Vector & refPoint)
        {
            m_refPoint = refPoint;
        }
        bool operator()(const Shape::Intersection & i1,
                        const Shape::Intersection & i2) const
        {
            return (m_refPoint.dist_to(i1.second)
                        < m_refPoint.dist_to(i2.second));
        }
    protected:
        Vector m_refPoint;
};

Shape::IntersectionList
Shape::IntersectionList::merge(const IntersectionList & other,
                               const Vector & startPoint)
{
    Shape::IntersectionList result;

    for (size_t i = 0, sz = m_intersections.size();
         i < sz;
         i++)
    {
        result.add(m_intersections[i]);
    }
    for (size_t i = 0, sz = other.m_intersections.size();
         i < sz;
         i++)
    {
        result.add(other.m_intersections[i]);
    }

    sort(result.begin(), result.end(), IntersectionComparator(startPoint));

    return result;
}