/*

 * shapes.cc: 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.

 */

#include "shapes.h"

#include "serialize.h"

bool Sphere::intersect(const Ray &ray, Float &dist) const

{

	Vector V = ray.o - center;

	register Float d = -dot(V, ray.dir);

	register Float Det = d * d - (dot(V,V) - sqr_radius);

	register Float t1,t2;

	if (Det > 0) {

		Det = sqrtf(Det);

		t1 = d - Det;

		t2 = d + Det;

		if (t1 > 0)

		{

			if (t1 < dist)

			{

				dist = t1;

				return true;

			}

		}

		else if (t2 > 0 && t2 < dist)

		{

			dist = t2;

			return true;

		}

	}

	return false;

}

#ifndef NO_SIMD

mfloat4 Sphere::intersect_packet(const RayPacket &rays, mfloat4 &dists) const

{

	VectorPacket V = rays.o - VectorPacket(center);

	mfloat4 d = msub(mZero, dot(V, rays.dir));

	mfloat4 Det = msub(mmul(d, d), msub(dot(V,V), mset1(sqr_radius)));

	mfloat4 t1, t2, mask;

	mask = mcmpgt(Det, mZero);

	if (!mmovemask(mask))

		return mask;

	Det = msqrt(Det);

	t1 = msub(d, Det);

	t2 = madd(d, Det);

	mask = mand(mask, mcmpgt(t2, mZero));

	const mfloat4 cond1 = mand(mcmpgt(t1, mZero), mcmplt(t1, dists));

	const mfloat4 cond2 = mand(mcmple(t1, mZero), mcmplt(t2, dists));

	const mfloat4 newdists = mor(mand(cond1, t1), mand(cond2, t2));

	mask = mand(mask, mor(cond1, cond2));

	dists = mselect(mask, newdists, dists);

	return mask;

}

#endif

/* if there should be CSG sometimes, this may be needed... */

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

{

	//allts = new vector<Float>();

	Vector V = ((Ray)ray).o - center;

	Float Vd = - dot(V, ray.dir);

	Float Det = Vd * Vd - (dot(V,V) - sqr_radius);

	if (Det > 0) {

		Det = sqrtf(Det);

		Float t1 = Vd - Det;

		Float t2 = Vd + Det;

		if (t1 < 0)

		{

			if (t2 > 0)

			{

				// ray from inside of the sphere

				allts.push_back(0.0);

				allts.push_back(t2);

				return true;

			}

			else

				return false;

		}

		else

		{

			allts.push_back(t1);

			allts.push_back(t2);

			return true;

		}

	}

	return false;

}

bool Sphere::intersect_bbox(const BBox &bbox) const

{

	register float dmin = 0;

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

	{

		if (center[i] < bbox.L[i])

			dmin += (center[i] - bbox.L[i])*(center[i] - bbox.L[i]);

		else

		if (center[i] > bbox.H[i])

			dmin += (center[i] - bbox.H[i])*(center[i] - bbox.H[i]);

	}

	if (dmin <= sqr_radius)

		return true;

	return false;

};

BBox Sphere::get_bbox() const

{

	return BBox(center - radius, center + radius);

}

bool Box::intersect(const Ray &ray, Float &dist) const

{

	register Float tnear = -Inf;

	register Float tfar = Inf;

	register Float t1, t2, t;

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

	{

		if (ray.dir[i] == 0) {

			/* ray is parallel to these planes */

			if (ray.o[i] < L[i] || ray.o[i] > H[i])

				return false;

		}

		else

		{

			/* compute the intersection distance of the planes */

			t1 = (L[i] - ray.o[i]) / ray.dir[i];

			t2 = (H[i] - ray.o[i]) / ray.dir[i];

			if (t1 > t2)

			{

				t = t1;

				t1 = t2;

				t2 = t;

			}

			if (t1 > tnear)

				tnear = t1; /* want largest Tnear */

			if (t2 < tfar)

				tfar = t2; /* want smallest Tfar */

			if (tnear > tfar || tfar < 0)

				return false; /* box missed; box is behind ray */

		}

	}

	if (tnear < dist)

	{

		dist = tnear;

		return true;

	}

	return false;

}

#ifndef NO_SIMD

mfloat4 Box::intersect_packet(const RayPacket &rays, mfloat4 &dists) const

{

	mfloat4 origin = rays.o.ma[0];

	mfloat4 invdir = rays.invdir.ma[0];

	mfloat4 t1 = mmul(msub(mset1(L[0]), origin), invdir);

	mfloat4 t2 = mmul(msub(mset1(H[0]), origin), invdir);

	mfloat4 tmin = mmin(t1, t2);

	mfloat4 tmax = mmax(t1, t2);

	origin = rays.o.ma[1];

	invdir = rays.invdir.ma[1];

	t1 = mmul(msub(mset1(L[1]), origin), invdir);

	t2 = mmul(msub(mset1(H[1]), origin), invdir);

	tmin = mmax(mmin(t1, t2), tmin);

	tmax = mmin(mmax(t1, t2), tmax);

	origin = rays.o.ma[2];

	invdir = rays.invdir.ma[2];

	t1 = mmul(msub(mset1(L[2]), origin), invdir);

	t2 = mmul(msub(mset1(H[2]), origin), invdir);

	tmin = mmax(mmin(t1, t2), tmin);

	tmax = mmin(mmax(t1, t2), tmax);

	mfloat4 mask = mand(mand(mcmplt(tmin, tmax), mcmpgt(tmax, mZero)), mcmplt(tmin, dists));

	dists = mselect(mask, tmin, dists);

	return mask;

}

#endif

bool Box::intersect_bbox(const BBox &bbox) const

{

	return (

	H.x > bbox.L.x && L.x < bbox.H.x &&

	H.y > bbox.L.y && L.y < bbox.H.y &&

	H.z > bbox.L.z && L.z < bbox.H.z);

}

const Vector Box::normal(const Vector &P) const

{

	Vector l = P - L;

	Vector h = H - P;

	if (l.x < h.x)

		h.x = -1;

	else

	{

		l.x = h.x;

		h.x = +1;

	}

	if (l.y < h.y)

		h.y = -1;

	else

	{

		l.y = h.y;

		h.y = +1;

	}

	if (l.z < h.z)

		h.z = -1;

	else

	{

		l.z = h.z;

		h.z = +1;

	}

	if (l.x > l.y)

	{

		h.x = 0;

		if (l.y > l.z)

			h.y = 0;

		else

			h.z = 0;

	}

	else

	{

		h.y = 0;

		if (l.x > l.z)

			h.x = 0;

		else

			h.z = 0;

	}

	return h;

}

#ifdef TRI_PLUCKER

inline void Plucker(const Vector &p, const Vector &q, Float* pl)

{

    pl[0] = p.x*q.y - q.x*p.y;

    pl[1] = p.x*q.z - q.x*p.z;

    pl[2] = p.x - q.x;

    pl[3] = p.y*q.z - q.y*p.z;

    pl[4] = p.z - q.z;

    pl[5] = q.y - p.y;

}

inline Float Side(const Float* pla, const Float* plb)

{

    return pla[0]*plb[4] + pla[1]*plb[5] + pla[2]*plb[3] + pla[4]*plb[0] + pla[5]*plb[1] + pla[3]*plb[2];

}

#endif

Triangle::Triangle(Vertex *aA, Vertex *aB, Vertex *aC, Material *amaterial)

	: A(aA), B(aB), C(aC)

{

	material = amaterial;

	const Vector c = B->P - A->P;

	const Vector b = C->P - A->P;

	N = cross(c, b);

	N.normalize();

#ifdef TRI_PLUCKER

	Plucker(B->P,C->P,pla);

	Plucker(C->P,A->P,plb);

	Plucker(A->P,B->P,plc);

#endif

#if defined(TRI_BARI) || defined(TRI_BARI_PRE)

	if (fabsf(N.x) > fabsf(N.y))

	{

		if (fabsf(N.x) > fabsf(N.z))

			k = 0;

		else

			k = 2;

	}

	else

	{

		if (fabsf(N.y) > fabsf(N.z))

			k = 1;

		else

			k = 2;

	}

#endif

#ifdef TRI_BARI_PRE

	int u = (k + 1) % 3;

	int v = (k + 2) % 3;

	Float krec = 1.0f / N[k];

	nu = N[u] * krec;

	nv = N[v] * krec;

	nd = dot(N, A->P) * krec;

	// first line equation

	Float reci = 1.0f / (b[u] * c[v] - b[v] * c[u]);

	bnu = b[u] * reci;

	bnv = -b[v] * reci;

	// second line equation

	cnu = -c[u] * reci;

	cnv = c[v] * reci;

#endif

}

bool Triangle::intersect(const Ray &ray, Float &dist) const

{

#ifdef TRI_PLUCKER

	Float plr[6];

	Plucker(ray.o, ray.o+ray.dir, plr);

	const bool side0 = Side(plr, pla) >= 0.0;

	const bool side1 = Side(plr, plb) >= 0.0;

	if (side0 != side1)

		return false;

	const bool side2 = Side(plr, plc) >= 0.0;

	if (side0 != side2)

		return false;

	const Float t = - dot( (ray.o - A->P), N) / dot(ray.dir,N);

	if(t <= Eps || t >= dist)

		return false;

	dist = t;

	return true;

#endif

#if defined(TRI_BARI) || defined(TRI_BARI_PRE)

	static const int modulo3[5] = {0,1,2,0,1};

	const Vector &O = ray.o;

	const Vector &D = ray.dir;

	register const int u = modulo3[k+1];

	register const int v = modulo3[k+2];

#endif

#ifdef TRI_BARI_PRE

	const Float t = (nd - O[k] - nu * O[u] - nv * O[v]) / (D[k] + nu * D[u] + nv * D[v]);

	if (t >= dist || t < Eps)

		return false;

	const Float hu = O[u] + t * D[u] - A->P[u];

	const Float hv = O[v] + t * D[v] - A->P[v];

	const Float beta = hv * bnu + hu * bnv;

	if (beta < 0.)

		return false;

	const Float gamma = hu * cnv + hv * cnu;

	if (gamma < 0. || beta + gamma > 1.)

		return false;

	dist = t;

	return true;

#endif

#ifdef TRI_BARI

	// original barycentric coordinates based intesection

	// not optimized, just for reference

	const Vector c = B - A;

	const Vector b = C - A;

	// distance test

	const Float t = - dot( (O-A), N) / dot(D,N);

	if (t < Eps || t > dist)

		return false;

	// calc hitpoint

	const Float Hu = O[u] + t * D[u] - A[u];

	const Float Hv = O[v] + t * D[v] - A[v];

	const Float beta = (b[u] * Hv - b[v] * Hu) / (b[u] * c[v] - b[v] * c[u]);

	if (beta < 0)

		return false;

	const Float gamma = (c[v] * Hu - c[u] * Hv) / (b[u] * c[v] - b[v] * c[u]);

	if (gamma < 0)

		return false;

	if (beta+gamma > 1)

		return false;

	dist = t;

	return true;

#endif

}

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

mfloat4 Triangle::intersect_packet(const RayPacket &rays, mfloat4 &dists) const

{

	static const int modulo3[5] = {0,1,2,0,1};

	register const int u = modulo3[k+1];

	register const int v = modulo3[k+2];

	mfloat4 mask;

	const mfloat4 t = mdiv(

		msub(msub(

		msub(mset1(nd), rays.o.ma[k]),

		mmul(mset1(nu), rays.o.ma[u])

		), mmul(mset1(nv), rays.o.ma[v])),

		madd(rays.dir.ma[k],

		madd(mmul(mset1(nu), rays.dir.ma[u]),

		mmul(mset1(nv), rays.dir.ma[v])))

		);

	mask = mand(mcmplt(t, dists), mcmpge(t, mEps));

	if (!mmovemask(mask))

		return mask;

	const mfloat4 hu = msub(madd(rays.o.ma[u],

		mmul(t, rays.dir.ma[u])), mset1(A->P[u]));

	const mfloat4 hv = msub(madd(rays.o.ma[v],

		mmul(t, rays.dir.ma[v])), mset1(A->P[v]));

	const mfloat4 beta = madd(mmul(hv, mset1(bnu)),

		mmul(hu, mset1(bnv)));

	mask = mand(mask, mcmpge(beta, mZero));

	if (!mmovemask(mask))

		return mask;

	const mfloat4 gamma = madd(mmul(hu, mset1(cnv)),

		mmul(hv, mset1(cnu)));

	mask = mand(mask, mand(mcmpge(gamma, mZero),

		mcmple(madd(beta, gamma), mOne)));

	if (!mmovemask(mask))

		return mask;

	dists = mselect(mask, t, dists);

	return mask;

}

#endif

bool Triangle::intersect_bbox(const BBox &bbox) const

{

	const Vector boxcenter = (bbox.L+bbox.H)*0.5;

	const Vector boxhalfsize = (bbox.H-bbox.L)*0.5;

	const Vector v0 = A->P - boxcenter;

	const Vector v1 = B->P - boxcenter;

	const Vector v2 = C->P - boxcenter;

	const Vector e0 = v1-v0;

	const Vector e1 = v2-v1;

	const Vector e2 = v0-v2;

	Float fex = fabsf(e0.x);

	Float fey = fabsf(e0.y);

	Float fez = fabsf(e0.z);

	Float p0,p1,p2,min,max,rad;

	p0 = e0.z*v0.y - e0.y*v0.z;

	p2 = e0.z*v2.y - e0.y*v2.z;

	if(p0<p2) {min=p0; max=p2;} else {min=p2; max=p0;}

	rad = fez * boxhalfsize.y + fey * boxhalfsize.z;

	if(min>rad || max<-rad) return false;

	p0 = -e0.z*v0.x + e0.x*v0.z;

	p2 = -e0.z*v2.x + e0.x*v2.z;

	if(p0<p2) {min=p0; max=p2;} else {min=p2; max=p0;}

	rad = fez * boxhalfsize.x + fex * boxhalfsize.z;

	if(min>rad || max<-rad) return false;

	p1 = e0.y*v1.x - e0.x*v1.y;

	p2 = e0.y*v2.x - e0.x*v2.y;

	if(p2<p1) {min=p2; max=p1;} else {min=p1; max=p2;}

	rad = fey * boxhalfsize.x + fex * boxhalfsize.y;

	if(min>rad || max<-rad) return false;