/**

 * @file  scene.h

 * @brief Classes for objects in scene (other than shapes).

 *

 * 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 SCENE_H

#define SCENE_H

#include <vector>

#include <typeinfo>

#include "common.h"

#include "sampler.h"

#include "vector.h"

#include "quaternion.h"

/**

 * A ray

 */

class Ray

{

public:

	Vector o;   ///< Origin

	Vector dir; ///< Normalized direction

	Ray(): o(), dir() {};

	Ray(const Vector &ao, const Vector &adir):

		o(ao), dir(adir) {};

};

#ifndef NO_SIMD

/**

 * Packet of four rays for SIMD accelerated packet tracing.

 */

class RayPacket

{

public:

	VectorPacket o;      ///< Packet of four origins

	VectorPacket dir;    ///< Directions

	VectorPacket invdir; ///< Inverted directions (1/dir)

	RayPacket(): o(), dir() {};

	RayPacket(const VectorPacket &ao, const VectorPacket &adir):

		o(ao), dir(adir), invdir(mOne/adir) {};

	/** Index operator: get ray 'i' */

	Ray operator[](int i) const

	{

		return Ray(

			Vector(o.x[i], o.y[i], o.z[i]),

			Vector(dir.x[i], dir.y[i], dir.z[i]));

	};

};

#endif

/**

 * General camera

 */

class Camera

{

	Vector eye, p, u, v;

	Float F;

public:

	Camera(): eye(0,0,10), p(0,0,-1), u(-1,0,0), v(0,1,0), F(2*tan(PI/8)) {};

	Camera(const Vector &C, const Vector &ap, const Vector &au, const Vector &av):

		eye(C), p(ap), u(au), v(av), F(2*tan(PI/8)) {};

	Camera(const Vector &from, const Vector &lookat, const Vector &up):

		eye(from), F(2*tan(PI/8))

	{

		p = lookat - from; u = cross(up, p);

		p.normalize(); u.normalize();

		v = cross(p, u);

	};

	const Vector &getEye() const { return eye; };

	const Vector &getp() const { return p; };

	const Vector &getu() const { return u; };

	const Vector &getv() const { return v; };

	const Float &getF() const { return F; };

	void setEye(const Vector &aeye) { eye = aeye; };

	void setp(const Vector &ap) { p = ap; };

	void setu(const Vector &au) { u = au; };

	void setv(const Vector &av) { v = av; };

	void setF(const Float &aF) { F = aF; };

	void setAngle(const Float angle) { F = 2*tan(angle/2); };

	void rotate(const Quaternion &q);

	void move(const Float fw, const Float left, const Float up);

	const Ray makeRay(const Sample &samp) const

	{

		Vector dir = normalize(p - (u*samp.x + v*samp.y)*F);

		return Ray(eye, dir);

	};

#ifndef NO_SIMD

	void makeRayPacket(const Sample *samples, RayPacket &rays) const

	{

		mfloat4 m1x,m1y,m1z;

		mfloat4 m2x,m2y,m2z;

		mfloat4 m;

		// m1(xyz) = u * samples[i].x

		m = mset(samples[3].x, samples[2].x, samples[1].x, samples[0].x);

		m1x = mmul(m1x, m);

		m1y = mmul(m1y, m);

		m1z = mmul(m1z, m);

		// m2(xyz) = v * samples[i].y

		m = mset(samples[3].y, samples[2].y, samples[1].y, samples[0].y);

		m2x = mmul(m2x, m);

		m2y = mmul(m2y, m);

		m2z = mmul(m2z, m);

		// m1(xyz) = (m1 + m2) = (u*samples[i].x + v*samples[i].y)

		m1x = madd(m1x, m2x);

		m1y = madd(m1y, m2y);

		m1z = madd(m1z, m2z);

		// m1(xyz) = m1*F = (u*samples[i].x + v*samples[i].y)*F

		m = mset1(F);

		m1x = mmul(m1x, m);

		m1y = mmul(m1y, m);

		m1z = mmul(m1z, m);

		// m1(xyz) = p - m1 = p - (u*samples[i].x + v*samples[i].y)*F = dir

		rays.dir.mx = msub(m2x, m1x);

		rays.dir.my = msub(m2y, m1y);

		rays.dir.mz = msub(m2z, m1z);

		// copy origin

		rays.dir.normalize();

	};

#endif

};

/**

 * light object

 */

class Light

{

public:

	Vector pos;

	Colour colour;

	int cast_shadows;

	Light():

		pos(Vector(0,0,0)), colour(Colour(1,1,1)), cast_shadows(true) {};

	Light(const Vector &position, const Colour &acolour):

		pos(position), colour(acolour), cast_shadows(true) {};

	void castShadows(int cast) { cast_shadows = cast; };

};

/**

 * axis-aligned bounding box

 */

class BBox

{

public:

	Vector L;

	Vector H;

	BBox(): L(), H() {};

	BBox(const Vector &aL, const Vector &aH): L(aL), H(aH) {};

	Float w() const { return H.x-L.x; };

	Float h() const { return H.y-L.y; };

	Float d() const { return H.z-L.z; };

	bool intersect(const Ray &ray, Float &a, Float &b) const;

#ifndef NO_SIMD

	mfloat4 intersect_packet(const RayPacket &rays, mfloat4 &a, mfloat4 &b) const;

#endif

};

#endif