/*
 * shapes.h: shape classes
 *
 * This file is part of Pyrit Ray Tracer.
 *
 * Copyright 2006, 2007, 2008  Radek Brich
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef SHAPES_H
#define SHAPES_H

#include "common.h"
#include "scene.h"

/*
triangle intersection alghoritm
options are:
TRI_PLUCKER
TRI_BARI
TRI_BARI_PRE
*/
#if !defined(TRI_PLUCKER) && !defined(TRI_BARI) && !defined(TRI_BARI_PRE)
#	define TRI_BARI_PRE
#endif

/**
 * shape
 */
class Shape
{
public:
	Material *material;
	Shape() {};
	virtual ~Shape() {};

	// first intersection point
	virtual bool intersect(const Ray &ray, Float &dist) const = 0;

	// all intersections (only for CSG)
	virtual bool intersect_all(const Ray &ray, Float dist, vector<Float> &allts) const = 0;

	// intersection with AABB
	virtual bool intersect_bbox(const BBox &bbox) const = 0;

	// normal at point P
	virtual const Vector3 normal(const Vector3 &P) const = 0;

	virtual BBox get_bbox() const = 0;

	virtual ostream & dump(ostream &st) const = 0;
};

/**
 * list of shapes
 */
typedef vector<Shape*> ShapeList;

/**
 * sphere shape
 */
class Sphere: public Shape
{
	Vector3 center;
	Float radius;

	Float sqr_radius;
	Float inv_radius;
public:
	Sphere(const Vector3 &acenter, const Float aradius, Material *amaterial):
		center(acenter), radius(aradius),
		sqr_radius(aradius*aradius), inv_radius(1.0f/aradius)
		{ material = amaterial; }
	bool intersect(const Ray &ray, Float &dist) const;
	bool intersect_all(const Ray &ray, Float dist, vector<Float> &allts) const;
	bool intersect_bbox(const BBox &bbox) const;
	const Vector3 normal(const Vector3 &P) const { return (P - center) * inv_radius; };
	BBox get_bbox() const;
	const Vector3 getCenter() const { return center; };
	const Float getRadius() const { return radius; };
	ostream & dump(ostream &st) const;
};

/**
 * box shape
 */
class Box: public Shape
{
	Vector3 L;
	Vector3 H;
public:
	Box(const Vector3 &aL, const Vector3 &aH, Material *amaterial): L(aL), H(aH)
	{
		for (int i = 0; i < 3; i++)
			if (L.cell[i] > H.cell[i])
				swap(L.cell[i], H.cell[i]);
		material = amaterial;
	};
	bool intersect(const Ray &ray, Float &dist) const;
	bool intersect_all(const Ray &ray, Float dist, vector<Float> &allts) const { return false; };
	bool intersect_bbox(const BBox &bbox) const;
	const Vector3 normal(const Vector3 &P) const;
	BBox get_bbox() const { return BBox(L, H); };
	const Vector3 getL() const { return L; };
	const Vector3 getH() const { return H; };
	ostream & dump(ostream &st) const;
};

/**
 * triangle vertex
 */
class Vertex
{
public:
	Vector3 P;
	Vertex(const Vector3 &aP): P(aP) {};
	virtual ostream & dump(ostream &st) const;
};

/**
 * triangle vertex with normal
 */
class NormalVertex: public Vertex
{
public:
	Vector3 N;
	NormalVertex(const NormalVertex *v): Vertex(v->P), N(v->N) {};
	NormalVertex(const Vector3 &aP): Vertex(aP) {};
	NormalVertex(const Vector3 &aP, const Vector3 &aN): Vertex(aP), N(aN) {};
	const Vector3 &getNormal() { return N; };
	void setNormal(const Vector3 &aN) { N = aN; };
	ostream & dump(ostream &st) const;
};

/**
 * triangle shape
 */
class Triangle: public Shape
{
#ifdef TRI_BARI_PRE
	Float nu, nv, nd;
	int k; // dominant axis
	Float bnu, bnv;
	Float cnu, cnv;
#endif
#ifdef TRI_BARI
	int k; // dominant axis
#endif
#ifdef TRI_PLUCKER
	Float pla[6], plb[6], plc[6];
#endif
	Vector3 N;
	const Vector3 smooth_normal(const Vector3 &P) const
	{
#ifdef TRI_BARI_PRE
		const Vector3 &NA = static_cast<NormalVertex*>(A)->N;
		const Vector3 &NB = static_cast<NormalVertex*>(B)->N;
		const Vector3 &NC = static_cast<NormalVertex*>(C)->N;
		static const int modulo3[5] = {0,1,2,0,1};
		register const int ku = modulo3[k+1];
		register const int kv = modulo3[k+2];
		const Float pu = P[ku] - A->P[ku];
		const Float pv = P[kv] - A->P[kv];
		const Float u = pv * bnu + pu * bnv;
		const Float v = pu * cnv + pv * cnu;
		Vector3 n = NA + u * (NB - NA) + v * (NC - NA);
		n.normalize();
		return n;
#else
		return N; // not implemented for other algorithms
#endif
	};
public:
	Vertex *A, *B, *C;

	Triangle() {};
	Triangle(Vertex *aA, Vertex *aB, Vertex *aC, Material *amaterial);
	bool intersect(const Ray &ray, Float &dist) const;
	bool intersect_all(const Ray &ray, Float dist, vector<Float> &allts) const {return false;};
	bool intersect_bbox(const BBox &bbox) const;
	const Vector3 normal(const Vector3 &P) const { return (material->smooth ? smooth_normal(P) : N); };
	const Vector3 getNormal() const { return N; };
	BBox get_bbox() const;
	ostream & dump(ostream &st) const;
};

template <class T> class Array
{
	T *array;
public:
	Array(int n) { array = new T[n]; };
	~Array() { delete[] array; };
	const T &operator[](int i) const { return array[i]; };
};

typedef Array<Vertex> VertexArray;
typedef Array<NormalVertex> NormalVertexArray;
typedef Array<Triangle> TriangleArray;

#endif