/**
 * @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

/**
 * Standard ray tracing 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)) {};

	/** Position + p,u,v constructor */
	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)) {};

	/** Look-at constructor */
	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);
	};

#ifndef NO_SIMD
	void *operator new(size_t size) { return _mm_malloc(size, 16); };
	void operator delete(void *p) { _mm_free(p); };
#endif

	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; };

	/** set "screen plane" size
	 * @param[in] F   height of the screen plane */
	void setF(const Float &aF) { F = aF; };

	/** set camera's angle of view (in radians) */
	void setAngle(const Float angle) { F = 2*tan(angle/2); };

	/** rotate camera using a quaternion */
	void rotate(const Quaternion &q);

	/** translate the camera in its direction
	 * @param[in] fw	size of forward step
	 * @param[in] left	size of left step
	 * @param[in] up	size of up step
	 */
	void move(const Float fw, const Float left, const Float up);

	/** make the ray from screen sample according the camera's parameters */
	const Ray makeRay(const Sample &samp) const
	{
		Vector dir = normalize(p - (u*samp.x + v*samp.y)*F);
		return Ray(eye, dir);
	};

	/** same as makeRay but for ray packet */
#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
		m1x = mshuffle(u.mf4, u.mf4, mShuffle0); // u.x
		m1y = mshuffle(u.mf4, u.mf4, mShuffle1); // u.y
		m1z = mshuffle(u.mf4, u.mf4, mShuffle2); // u.z
		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
		m2x = mshuffle(v.mf4, v.mf4, mShuffle0); // v.x
		m2y = mshuffle(v.mf4, v.mf4, mShuffle1); // v.y
		m2z = mshuffle(v.mf4, v.mf4, mShuffle2); // v.z
		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
		m2x = mshuffle(p.mf4, p.mf4, mShuffle0); // p.x
		m2y = mshuffle(p.mf4, p.mf4, mShuffle1); // p.y
		m2z = mshuffle(p.mf4, p.mf4, mShuffle2); // p.z
		rays.dir.mx = msub(m2x, m1x);
		rays.dir.my = msub(m2y, m1y);
		rays.dir.mz = msub(m2z, m1z);

		// copy origin
		rays.o.mx = mshuffle(eye.mf4, eye.mf4, mShuffle0); // eye.x
		rays.o.my = mshuffle(eye.mf4, eye.mf4, mShuffle1); // eye.y
		rays.o.mz = mshuffle(eye.mf4, eye.mf4, mShuffle2); // eye.z

		rays.dir.normalize();
		rays.invdir = mOne / rays.dir;
	};
#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) {};

	/** allow shadows from this light */
	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; };

	/**
	 * intersect ray with the bounding box
	 * @param[in] ray	the ray
	 * @param[out] a	distance of first intersection
	 * @param[out] b	distance of second intersection
	 * @return true if ray intersects bbox
	 */
	bool intersect(const Ray &ray, Float &a, Float &b) const;

	/** same as intersect() but for ray packets */
#ifndef NO_SIMD
	mfloat4 intersect_packet(const RayPacket &rays, mfloat4 &a, mfloat4 &b) const;
#endif
};

#endif