godot/thirdparty/embree/kernels/geometry/triangle_intersector_moeller.h

404 lines
16 KiB
C++

// Copyright 2009-2020 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "triangle.h"
#include "intersector_epilog.h"
/*! This intersector implements a modified version of the Moeller
* Trumbore intersector from the paper "Fast, Minimum Storage
* Ray-Triangle Intersection". In contrast to the paper we
* precalculate some factors and factor the calculations differently
* to allow precalculating the cross product e1 x e2. The resulting
* algorithm is similar to the fastest one of the paper "Optimizing
* Ray-Triangle Intersection via Automated Search". */
namespace embree
{
namespace isa
{
template<int M>
struct MoellerTrumboreHitM
{
__forceinline MoellerTrumboreHitM() {}
__forceinline MoellerTrumboreHitM(const vbool<M>& valid, const vfloat<M>& U, const vfloat<M>& V, const vfloat<M>& T, const vfloat<M>& absDen, const Vec3vf<M>& Ng)
: U(U), V(V), T(T), absDen(absDen), valid(valid), vNg(Ng) {}
__forceinline void finalize()
{
const vfloat<M> rcpAbsDen = rcp(absDen);
vt = T * rcpAbsDen;
vu = U * rcpAbsDen;
vv = V * rcpAbsDen;
}
__forceinline Vec2f uv (const size_t i) const { return Vec2f(vu[i],vv[i]); }
__forceinline float t (const size_t i) const { return vt[i]; }
__forceinline Vec3fa Ng(const size_t i) const { return Vec3fa(vNg.x[i],vNg.y[i],vNg.z[i]); }
public:
vfloat<M> U;
vfloat<M> V;
vfloat<M> T;
vfloat<M> absDen;
public:
vbool<M> valid;
vfloat<M> vu;
vfloat<M> vv;
vfloat<M> vt;
Vec3vf<M> vNg;
};
template<int M>
struct MoellerTrumboreIntersector1
{
__forceinline MoellerTrumboreIntersector1() {}
__forceinline MoellerTrumboreIntersector1(const Ray& ray, const void* ptr) {}
__forceinline bool intersect(const vbool<M>& valid0,
Ray& ray,
const Vec3vf<M>& tri_v0,
const Vec3vf<M>& tri_e1,
const Vec3vf<M>& tri_e2,
const Vec3vf<M>& tri_Ng,
MoellerTrumboreHitM<M>& hit) const
{
/* calculate denominator */
vbool<M> valid = valid0;
const Vec3vf<M> O = Vec3vf<M>((Vec3fa)ray.org);
const Vec3vf<M> D = Vec3vf<M>((Vec3fa)ray.dir);
const Vec3vf<M> C = Vec3vf<M>(tri_v0) - O;
const Vec3vf<M> R = cross(C,D);
const vfloat<M> den = dot(Vec3vf<M>(tri_Ng),D);
const vfloat<M> absDen = abs(den);
const vfloat<M> sgnDen = signmsk(den);
/* perform edge tests */
const vfloat<M> U = dot(R,Vec3vf<M>(tri_e2)) ^ sgnDen;
const vfloat<M> V = dot(R,Vec3vf<M>(tri_e1)) ^ sgnDen;
/* perform backface culling */
#if defined(EMBREE_BACKFACE_CULLING)
valid &= (den < vfloat<M>(zero)) & (U >= 0.0f) & (V >= 0.0f) & (U+V<=absDen);
#else
valid &= (den != vfloat<M>(zero)) & (U >= 0.0f) & (V >= 0.0f) & (U+V<=absDen);
#endif
if (likely(none(valid))) return false;
/* perform depth test */
const vfloat<M> T = dot(Vec3vf<M>(tri_Ng),C) ^ sgnDen;
valid &= (absDen*vfloat<M>(ray.tnear()) < T) & (T <= absDen*vfloat<M>(ray.tfar));
if (likely(none(valid))) return false;
/* update hit information */
new (&hit) MoellerTrumboreHitM<M>(valid,U,V,T,absDen,tri_Ng);
return true;
}
__forceinline bool intersectEdge(Ray& ray,
const Vec3vf<M>& tri_v0,
const Vec3vf<M>& tri_e1,
const Vec3vf<M>& tri_e2,
MoellerTrumboreHitM<M>& hit) const
{
vbool<M> valid = true;
const Vec3<vfloat<M>> tri_Ng = cross(tri_e2,tri_e1);
return intersect(valid,ray,tri_v0,tri_e1,tri_e2,tri_Ng,hit);
}
__forceinline bool intersect(Ray& ray,
const Vec3vf<M>& v0,
const Vec3vf<M>& v1,
const Vec3vf<M>& v2,
MoellerTrumboreHitM<M>& hit) const
{
const Vec3vf<M> e1 = v0-v1;
const Vec3vf<M> e2 = v2-v0;
return intersectEdge(ray,v0,e1,e2,hit);
}
__forceinline bool intersect(const vbool<M>& valid,
Ray& ray,
const Vec3vf<M>& v0,
const Vec3vf<M>& v1,
const Vec3vf<M>& v2,
MoellerTrumboreHitM<M>& hit) const
{
const Vec3vf<M> e1 = v0-v1;
const Vec3vf<M> e2 = v2-v0;
return intersectEdge(valid,ray,v0,e1,e2,hit);
}
template<typename Epilog>
__forceinline bool intersectEdge(Ray& ray,
const Vec3vf<M>& v0,
const Vec3vf<M>& e1,
const Vec3vf<M>& e2,
const Epilog& epilog) const
{
MoellerTrumboreHitM<M> hit;
if (likely(intersectEdge(ray,v0,e1,e2,hit))) return epilog(hit.valid,hit);
return false;
}
template<typename Epilog>
__forceinline bool intersect(Ray& ray,
const Vec3vf<M>& v0,
const Vec3vf<M>& v1,
const Vec3vf<M>& v2,
const Epilog& epilog) const
{
MoellerTrumboreHitM<M> hit;
if (likely(intersect(ray,v0,v1,v2,hit))) return epilog(hit.valid,hit);
return false;
}
template<typename Epilog>
__forceinline bool intersect(const vbool<M>& valid,
Ray& ray,
const Vec3vf<M>& v0,
const Vec3vf<M>& v1,
const Vec3vf<M>& v2,
const Epilog& epilog) const
{
MoellerTrumboreHitM<M> hit;
if (likely(intersect(valid,ray,v0,v1,v2,hit))) return epilog(hit.valid,hit);
return false;
}
};
template<int K>
struct MoellerTrumboreHitK
{
__forceinline MoellerTrumboreHitK(const vfloat<K>& U, const vfloat<K>& V, const vfloat<K>& T, const vfloat<K>& absDen, const Vec3vf<K>& Ng)
: U(U), V(V), T(T), absDen(absDen), Ng(Ng) {}
__forceinline std::tuple<vfloat<K>,vfloat<K>,vfloat<K>,Vec3vf<K>> operator() () const
{
const vfloat<K> rcpAbsDen = rcp(absDen);
const vfloat<K> t = T * rcpAbsDen;
const vfloat<K> u = U * rcpAbsDen;
const vfloat<K> v = V * rcpAbsDen;
return std::make_tuple(u,v,t,Ng);
}
private:
const vfloat<K> U;
const vfloat<K> V;
const vfloat<K> T;
const vfloat<K> absDen;
const Vec3vf<K> Ng;
};
template<int M, int K>
struct MoellerTrumboreIntersectorK
{
__forceinline MoellerTrumboreIntersectorK(const vbool<K>& valid, const RayK<K>& ray) {}
/*! Intersects K rays with one of M triangles. */
template<typename Epilog>
__forceinline vbool<K> intersectK(const vbool<K>& valid0,
//RayK<K>& ray,
const Vec3vf<K>& ray_org,
const Vec3vf<K>& ray_dir,
const vfloat<K>& ray_tnear,
const vfloat<K>& ray_tfar,
const Vec3vf<K>& tri_v0,
const Vec3vf<K>& tri_e1,
const Vec3vf<K>& tri_e2,
const Vec3vf<K>& tri_Ng,
const Epilog& epilog) const
{
/* calculate denominator */
vbool<K> valid = valid0;
const Vec3vf<K> C = tri_v0 - ray_org;
const Vec3vf<K> R = cross(C,ray_dir);
const vfloat<K> den = dot(tri_Ng,ray_dir);
const vfloat<K> absDen = abs(den);
const vfloat<K> sgnDen = signmsk(den);
/* test against edge p2 p0 */
const vfloat<K> U = dot(tri_e2,R) ^ sgnDen;
valid &= U >= 0.0f;
if (likely(none(valid))) return false;
/* test against edge p0 p1 */
const vfloat<K> V = dot(tri_e1,R) ^ sgnDen;
valid &= V >= 0.0f;
if (likely(none(valid))) return false;
/* test against edge p1 p2 */
const vfloat<K> W = absDen-U-V;
valid &= W >= 0.0f;
if (likely(none(valid))) return false;
/* perform depth test */
const vfloat<K> T = dot(tri_Ng,C) ^ sgnDen;
valid &= (absDen*ray_tnear < T) & (T <= absDen*ray_tfar);
if (unlikely(none(valid))) return false;
/* perform backface culling */
#if defined(EMBREE_BACKFACE_CULLING)
valid &= den < vfloat<K>(zero);
if (unlikely(none(valid))) return false;
#else
valid &= den != vfloat<K>(zero);
if (unlikely(none(valid))) return false;
#endif
/* calculate hit information */
MoellerTrumboreHitK<K> hit(U,V,T,absDen,tri_Ng);
return epilog(valid,hit);
}
/*! Intersects K rays with one of M triangles. */
template<typename Epilog>
__forceinline vbool<K> intersectK(const vbool<K>& valid0,
RayK<K>& ray,
const Vec3vf<K>& tri_v0,
const Vec3vf<K>& tri_v1,
const Vec3vf<K>& tri_v2,
const Epilog& epilog) const
{
const Vec3vf<K> e1 = tri_v0-tri_v1;
const Vec3vf<K> e2 = tri_v2-tri_v0;
const Vec3vf<K> Ng = cross(e2,e1);
return intersectK(valid0,ray.org,ray.dir,ray.tnear(),ray.tfar,tri_v0,e1,e2,Ng,epilog);
}
/*! Intersects K rays with one of M triangles. */
template<typename Epilog>
__forceinline vbool<K> intersectEdgeK(const vbool<K>& valid0,
RayK<K>& ray,
const Vec3vf<K>& tri_v0,
const Vec3vf<K>& tri_e1,
const Vec3vf<K>& tri_e2,
const Epilog& epilog) const
{
const Vec3vf<K> tri_Ng = cross(tri_e2,tri_e1);
return intersectK(valid0,ray.org,ray.dir,ray.tnear(),ray.tfar,tri_v0,tri_e1,tri_e2,tri_Ng,epilog);
}
/*! Intersect k'th ray from ray packet of size K with M triangles. */
__forceinline bool intersectEdge(RayK<K>& ray,
size_t k,
const Vec3vf<M>& tri_v0,
const Vec3vf<M>& tri_e1,
const Vec3vf<M>& tri_e2,
MoellerTrumboreHitM<M>& hit) const
{
/* calculate denominator */
typedef Vec3vf<M> Vec3vfM;
const Vec3vf<M> tri_Ng = cross(tri_e2,tri_e1);
const Vec3vfM O = broadcast<vfloat<M>>(ray.org,k);
const Vec3vfM D = broadcast<vfloat<M>>(ray.dir,k);
const Vec3vfM C = Vec3vfM(tri_v0) - O;
const Vec3vfM R = cross(C,D);
const vfloat<M> den = dot(Vec3vfM(tri_Ng),D);
const vfloat<M> absDen = abs(den);
const vfloat<M> sgnDen = signmsk(den);
/* perform edge tests */
const vfloat<M> U = dot(Vec3vf<M>(tri_e2),R) ^ sgnDen;
const vfloat<M> V = dot(Vec3vf<M>(tri_e1),R) ^ sgnDen;
/* perform backface culling */
#if defined(EMBREE_BACKFACE_CULLING)
vbool<M> valid = (den < vfloat<M>(zero)) & (U >= 0.0f) & (V >= 0.0f) & (U+V<=absDen);
#else
vbool<M> valid = (den != vfloat<M>(zero)) & (U >= 0.0f) & (V >= 0.0f) & (U+V<=absDen);
#endif
if (likely(none(valid))) return false;
/* perform depth test */
const vfloat<M> T = dot(Vec3vf<M>(tri_Ng),C) ^ sgnDen;
valid &= (absDen*vfloat<M>(ray.tnear()[k]) < T) & (T <= absDen*vfloat<M>(ray.tfar[k]));
if (likely(none(valid))) return false;
/* calculate hit information */
new (&hit) MoellerTrumboreHitM<M>(valid,U,V,T,absDen,tri_Ng);
return true;
}
__forceinline bool intersectEdge(RayK<K>& ray,
size_t k,
const BBox<vfloat<M>>& time_range,
const Vec3vf<M>& tri_v0,
const Vec3vf<M>& tri_e1,
const Vec3vf<M>& tri_e2,
MoellerTrumboreHitM<M>& hit) const
{
if (likely(intersect(ray,k,tri_v0,tri_e1,tri_e2,hit)))
{
hit.valid &= time_range.lower <= vfloat<M>(ray.time[k]);
hit.valid &= vfloat<M>(ray.time[k]) < time_range.upper;
return any(hit.valid);
}
return false;
}
template<typename Epilog>
__forceinline bool intersectEdge(RayK<K>& ray,
size_t k,
const Vec3vf<M>& tri_v0,
const Vec3vf<M>& tri_e1,
const Vec3vf<M>& tri_e2,
const Epilog& epilog) const
{
MoellerTrumboreHitM<M> hit;
if (likely(intersectEdge(ray,k,tri_v0,tri_e1,tri_e2,hit))) return epilog(hit.valid,hit);
return false;
}
template<typename Epilog>
__forceinline bool intersectEdge(RayK<K>& ray,
size_t k,
const BBox<vfloat<M>>& time_range,
const Vec3vf<M>& tri_v0,
const Vec3vf<M>& tri_e1,
const Vec3vf<M>& tri_e2,
const Epilog& epilog) const
{
MoellerTrumboreHitM<M> hit;
if (likely(intersectEdge(ray,k,time_range,tri_v0,tri_e1,tri_e2,hit))) return epilog(hit.valid,hit);
return false;
}
template<typename Epilog>
__forceinline bool intersect(RayK<K>& ray,
size_t k,
const Vec3vf<M>& v0,
const Vec3vf<M>& v1,
const Vec3vf<M>& v2,
const Epilog& epilog) const
{
const Vec3vf<M> e1 = v0-v1;
const Vec3vf<M> e2 = v2-v0;
return intersectEdge(ray,k,v0,e1,e2,epilog);
}
template<typename Epilog>
__forceinline bool intersect(RayK<K>& ray,
size_t k,
const BBox<vfloat<M>>& time_range,
const Vec3vf<M>& v0,
const Vec3vf<M>& v1,
const Vec3vf<M>& v2,
const Epilog& epilog) const
{
const Vec3vf<M> e1 = v0-v1;
const Vec3vf<M> e2 = v2-v0;
return intersectEdge(ray,k,time_range,v0,e1,e2,epilog);
}
};
}
}