virtualx-engine/thirdparty/embree/kernels/geometry/sphere_intersector.h
2021-01-14 18:02:07 +01:00

183 lines
6.7 KiB
C++

// Copyright 2009-2020 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "../common/ray.h"
#include "../common/scene_points.h"
#include "curve_intersector_precalculations.h"
namespace embree
{
namespace isa
{
template<int M>
struct SphereIntersectorHitM
{
__forceinline SphereIntersectorHitM() {}
__forceinline SphereIntersectorHitM(const vfloat<M>& t, const Vec3vf<M>& Ng)
: vt(t), vNg(Ng) {}
__forceinline void finalize() {}
__forceinline Vec2f uv(const size_t i) const {
return Vec2f(0.0f, 0.0f);
}
__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> vt;
Vec3vf<M> vNg;
};
template<int M>
struct SphereIntersector1
{
typedef CurvePrecalculations1 Precalculations;
template<typename Epilog>
static __forceinline bool intersect(
const vbool<M>& valid_i, Ray& ray,
const Precalculations& pre, const Vec4vf<M>& v0, const Epilog& epilog)
{
vbool<M> valid = valid_i;
const vfloat<M> rd2 = rcp(dot(ray.dir, ray.dir));
const Vec3vf<M> ray_org(ray.org.x, ray.org.y, ray.org.z);
const Vec3vf<M> ray_dir(ray.dir.x, ray.dir.y, ray.dir.z);
const Vec3vf<M> center = v0.xyz();
const vfloat<M> radius = v0.w;
const Vec3vf<M> c0 = center - ray_org;
const vfloat<M> projC0 = dot(c0, ray_dir) * rd2;
const Vec3vf<M> perp = c0 - projC0 * ray_dir;
const vfloat<M> l2 = dot(perp, perp);
const vfloat<M> r2 = radius * radius;
valid &= (l2 <= r2);
if (unlikely(none(valid)))
return false;
const vfloat<M> td = sqrt((r2 - l2) * rd2);
const vfloat<M> t_front = projC0 - td;
const vfloat<M> t_back = projC0 + td;
const vbool<M> valid_front = valid & (ray.tnear() <= t_front) & (t_front <= ray.tfar);
const vbool<M> valid_back = valid & (ray.tnear() <= t_back ) & (t_back <= ray.tfar);
/* check if there is a first hit */
const vbool<M> valid_first = valid_front | valid_back;
if (unlikely(none(valid_first)))
return false;
/* construct first hit */
const vfloat<M> td_front = -td;
const vfloat<M> td_back = +td;
const vfloat<M> t_first = select(valid_front, t_front, t_back);
const Vec3vf<M> Ng_first = select(valid_front, td_front, td_back) * ray_dir - perp;
SphereIntersectorHitM<M> hit(t_first, Ng_first);
/* invoke intersection filter for first hit */
const bool is_hit_first = epilog(valid_first, hit);
/* check for possible second hits before potentially accepted hit */
const vfloat<M> t_second = t_back;
const vbool<M> valid_second = valid_front & valid_back & (t_second <= ray.tfar);
if (unlikely(none(valid_second)))
return is_hit_first;
/* invoke intersection filter for second hit */
const Vec3vf<M> Ng_second = td_back * ray_dir - perp;
hit = SphereIntersectorHitM<M> (t_second, Ng_second);
const bool is_hit_second = epilog(valid_second, hit);
return is_hit_first | is_hit_second;
}
template<typename Epilog>
static __forceinline bool intersect(
const vbool<M>& valid_i, Ray& ray, IntersectContext* context, const Points* geom,
const Precalculations& pre, const Vec4vf<M>& v0i, const Epilog& epilog)
{
const Vec3vf<M> ray_org(ray.org.x, ray.org.y, ray.org.z);
const Vec4vf<M> v0 = enlargeRadiusToMinWidth(context,geom,ray_org,v0i);
return intersect(valid_i,ray,pre,v0,epilog);
}
};
template<int M, int K>
struct SphereIntersectorK
{
typedef CurvePrecalculationsK<K> Precalculations;
template<typename Epilog>
static __forceinline bool intersect(const vbool<M>& valid_i,
RayK<K>& ray, size_t k,
IntersectContext* context,
const Points* geom,
const Precalculations& pre,
const Vec4vf<M>& v0i,
const Epilog& epilog)
{
vbool<M> valid = valid_i;
const Vec3vf<M> ray_org(ray.org.x[k], ray.org.y[k], ray.org.z[k]);
const Vec3vf<M> ray_dir(ray.dir.x[k], ray.dir.y[k], ray.dir.z[k]);
const vfloat<M> rd2 = rcp(dot(ray_dir, ray_dir));
const Vec4vf<M> v0 = enlargeRadiusToMinWidth(context,geom,ray_org,v0i);
const Vec3vf<M> center = v0.xyz();
const vfloat<M> radius = v0.w;
const Vec3vf<M> c0 = center - ray_org;
const vfloat<M> projC0 = dot(c0, ray_dir) * rd2;
const Vec3vf<M> perp = c0 - projC0 * ray_dir;
const vfloat<M> l2 = dot(perp, perp);
const vfloat<M> r2 = radius * radius;
valid &= (l2 <= r2);
if (unlikely(none(valid)))
return false;
const vfloat<M> td = sqrt((r2 - l2) * rd2);
const vfloat<M> t_front = projC0 - td;
const vfloat<M> t_back = projC0 + td;
const vbool<M> valid_front = valid & (ray.tnear()[k] <= t_front) & (t_front <= ray.tfar[k]);
const vbool<M> valid_back = valid & (ray.tnear()[k] <= t_back ) & (t_back <= ray.tfar[k]);
/* check if there is a first hit */
const vbool<M> valid_first = valid_front | valid_back;
if (unlikely(none(valid_first)))
return false;
/* construct first hit */
const vfloat<M> td_front = -td;
const vfloat<M> td_back = +td;
const vfloat<M> t_first = select(valid_front, t_front, t_back);
const Vec3vf<M> Ng_first = select(valid_front, td_front, td_back) * ray_dir - perp;
SphereIntersectorHitM<M> hit(t_first, Ng_first);
/* invoke intersection filter for first hit */
const bool is_hit_first = epilog(valid_first, hit);
/* check for possible second hits before potentially accepted hit */
const vfloat<M> t_second = t_back;
const vbool<M> valid_second = valid_front & valid_back & (t_second <= ray.tfar[k]);
if (unlikely(none(valid_second)))
return is_hit_first;
/* invoke intersection filter for second hit */
const Vec3vf<M> Ng_second = td_back * ray_dir - perp;
hit = SphereIntersectorHitM<M> (t_second, Ng_second);
const bool is_hit_second = epilog(valid_second, hit);
return is_hit_first | is_hit_second;
}
};
} // namespace isa
} // namespace embree