#if !defined(AFX_IMINDISTANCE_H__029401C5_EC54_41FD_B8C8_5B65BA17BC4F__INCLUDED_)
#define AFX_IMINDISTANCE_H__029401C5_EC54_41FD_B8C8_5B65BA17BC4F__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

#include "mathlib.h"	// Point
#include "tuples.h"	// Pair
#include "ADFCreator_debug_flags.h"

#include <iostream>
using namespace std;

namespace SDF {

	enum PointClass {INTERIOR, EXTERIOR, DONT_KNOW};
	ostream& operator<< (ostream &os, const PointClass &ptclass);

	class SdfValue {

		friend ostream& operator<< (ostream &os, const SdfValue &sdf);

	public:
		double abs_distance;
		Point closest_point;
		Vector gradient;
		PointClass dist_class;

		SdfValue(const double &abs_dist,
			const Point &Pc,
			const Vector &grad,
			const PointClass &klass)
			: abs_distance(abs_dist)
			, closest_point(Pc)
			, gradient(grad)
			, dist_class(klass)
		{
			if(!( this->abs_distance >= 0.0f )) {
				__ERROR__("Someone tried to create an SdfValue with a negative abs_dist: " << this->abs_distance);
				assert(this->abs_distance >= 0.0f);
			}
		}	

		double getSignedDistance() const {
			if(this->dist_class == INTERIOR) {
				return this->abs_distance;
			}
			else if(this->dist_class == EXTERIOR) {
				return -1.0f * this->abs_distance;
			}
			else {
				__ERROR__("Someone tried to read a signed distance field, but the distance class was unknown.");
				assert(false);
				return 0.0f;
			}
		}
	};

	//-----------------------
	//	Implementors should be geometry objects for which
	//	signed distance fields from a given point can be calculated.
	//
	//	An implementor may or may not use the TriMeshSdfAlgo's.
	//	For example, an implementation for a sphere would not need those algorithms.
	//-----------------------
	class ISDF
	{
	public:
		// Make sure this is virtual..pretty important
		virtual SdfValue calc_sdf_from_pt(const Point &from) const = 0;
	};

}
#endif // !defined(AFX_IMINDISTANCE_H__029401C5_EC54_41FD_B8C8_5B65BA17BC4F__INCLUDED_)