/**

 * @file  shapes.h

 * @brief Shape classes: Box, Sphere, Triangle and helpers

 *

 * 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"

#include "material.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

/**

 * abstract shape class

 */

class Shape

{

public:

	Material *material;

	Shape() {};

	virtual ~Shape() {};

	/**

	 * intersect ray with sphere

	 * @param[in] ray	the ray

	 * @param[in] dist	maximum allowed distance of intersection

	 * @param[out] dist	distance of the intersection if found, unchanged otherwise

	 * @return true if ray intersects the sphere

	 */

	virtual bool intersect(const Ray &ray, Float &dist) const = 0;

	/**

	 * same as intersect, but for ray packets

	 */

#ifndef NO_SIMD

	virtual mfloat4 intersect_packet(const RayPacket &rays, mfloat4 &dists) const

	{

	};

#endif

	/** get all intersections -- not needed nor used currently */

	virtual bool intersect_all(const Ray &ray, Float dist, vector<Float> &allts) const = 0;

	/** test intersection with bounding box */

	virtual bool intersect_bbox(const BBox &bbox) const = 0;

	/** get surface normal at point P */

	virtual const Vector normal(const Vector &P) const = 0;

	/** get bounding box of this shape */

	virtual BBox get_bbox() const = 0;

	/** write textual representation of the shape to stream */

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

};

/**

 * list of shapes

 */

typedef vector<const Shape*> ShapeList;

/**

 * sphere shape

 */

class Sphere: public Shape

{

	Vector center;

	Float radius;

	Float sqr_radius;

	Float inv_radius;

public:

	Sphere(const Vector &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;

#ifndef NO_SIMD

	mfloat4 intersect_packet(const RayPacket &rays, mfloat4 &dists) const;

#endif

	bool intersect_all(const Ray &ray, Float dist, vector<Float> &allts) const;

	bool intersect_bbox(const BBox &bbox) const;

	const Vector normal(const Vector &P) const { return (P - center) * inv_radius; };

	BBox get_bbox() const;

	const Vector getCenter() const { return center; };

	Float getRadius() const { return radius; };

	ostream & dump(ostream &st) const;

};

/**

 * box shape

 */

class Box: public Shape

{

	Vector L;

	Vector H;

public:

	Box(const Vector &aL, const Vector &aH, Material *amaterial): L(aL), H(aH)

	{

		for (int i = 0; i < 3; i++)

			if (L[i] > H[i])

				swap(L[i], H[i]);

		material = amaterial;

	};

	bool intersect(const Ray &ray, Float &dist) const;

#ifndef NO_SIMD

	mfloat4 intersect_packet(const RayPacket &rays, mfloat4 &dists) const;

#endif

	bool intersect_all(const Ray &ray, Float dist, vector<Float> &allts) const { return false; };

	bool intersect_bbox(const BBox &bbox) const;

	const Vector normal(const Vector &P) const;

	BBox get_bbox() const { return BBox(L, H); };

	const Vector getL() const { return L; };

	const Vector getH() const { return H; };

	ostream & dump(ostream &st) const;

};

/**

 * triangle vertex

 */

class Vertex

{

public:

	Vector P;

	Vertex(const Vector &aP): P(aP) {};

	virtual ~Vertex() {};

	virtual ostream & dump(ostream &st) const;

};

/**

 * triangle vertex with normal

 */

class NormalVertex: public Vertex

{

public:

	Vector N;

	NormalVertex(const NormalVertex *v): Vertex(v->P), N(v->N) {};

	NormalVertex(const Vector &aP): Vertex(aP) {};

	NormalVertex(const Vector &aP, const Vector &aN): Vertex(aP), N(aN) {};

	const Vector &getNormal() { return N; };

	void setNormal(const Vector &aN) { N = aN; };

	ostream & dump(ostream &st) const;

};

/**

 * triangle shape

 */

class Triangle: public Shape

{

	Vector N;

#ifdef TRI_BARI_PRE

	Float nu, nv, nd;

	Float bnu, bnv;

	Float cnu, cnv;

	int k; // dominant axis

#endif

#ifdef TRI_BARI

	int k; // dominant axis

#endif

#ifdef TRI_PLUCKER

	Float pla[6], plb[6], plc[6];

#endif

	const Vector smooth_normal(const Vector &P) const

	{

#ifdef TRI_BARI_PRE

		const Vector &NA = static_cast<NormalVertex*>(A)->N;

		const Vector &NB = static_cast<NormalVertex*>(B)->N;

		const Vector &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;

		Vector 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;

#if !defined(NO_SIMD) && defined(TRI_BARI_PRE)

	mfloat4 intersect_packet(const RayPacket &rays, mfloat4 &dists) const;

#endif

	bool intersect_all(const Ray &ray, Float dist, vector<Float> &allts) const {return false;};

	bool intersect_bbox(const BBox &bbox) const;

	const Vector normal(const Vector &P) const { return (material->smooth ? smooth_normal(P) : N); };

	BBox get_bbox() const;

	/** get real normal of the triangle */

	const Vector getNormal() const { return N; };

	ostream & dump(ostream &st) const;

};

/** template for triangle arrays, currently not used */

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