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// Copyright 2009-2021 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "node_intersector.h"
namespace embree
{
namespace isa
{
//////////////////////////////////////////////////////////////////////////////////////
// Frustum structure used in hybrid and stream traversal
//////////////////////////////////////////////////////////////////////////////////////
/*
Optimized frustum test. We calculate t=(p-org)/dir in ray/box
intersection. We assume the rays are split by octant, thus
dir intervals are either positive or negative in each
dimension.
Case 1: dir.min >= 0 && dir.max >= 0:
t_min = (p_min - org_max) / dir_max = (p_min - org_max)*rdir_min = p_min*rdir_min - org_max*rdir_min
t_max = (p_max - org_min) / dir_min = (p_max - org_min)*rdir_max = p_max*rdir_max - org_min*rdir_max
Case 2: dir.min < 0 && dir.max < 0:
t_min = (p_max - org_min) / dir_min = (p_max - org_min)*rdir_max = p_max*rdir_max - org_min*rdir_max
t_max = (p_min - org_max) / dir_max = (p_min - org_max)*rdir_min = p_min*rdir_min - org_max*rdir_min
*/
template<bool robust>
struct Frustum;
/* Fast variant */
template<>
struct Frustum<false>
{
__forceinline Frustum() {}
template<int K>
__forceinline void init(const vbool<K>& valid, const Vec3vf<K>& org, const Vec3vf<K>& rdir, const vfloat<K>& ray_tnear, const vfloat<K>& ray_tfar, int N)
{
const Vec3fa reduced_min_org(reduce_min(select(valid, org.x, pos_inf)),
reduce_min(select(valid, org.y, pos_inf)),
reduce_min(select(valid, org.z, pos_inf)));
const Vec3fa reduced_max_org(reduce_max(select(valid, org.x, neg_inf)),
reduce_max(select(valid, org.y, neg_inf)),
reduce_max(select(valid, org.z, neg_inf)));
const Vec3fa reduced_min_rdir(reduce_min(select(valid, rdir.x, pos_inf)),
reduce_min(select(valid, rdir.y, pos_inf)),
reduce_min(select(valid, rdir.z, pos_inf)));
const Vec3fa reduced_max_rdir(reduce_max(select(valid, rdir.x, neg_inf)),
reduce_max(select(valid, rdir.y, neg_inf)),
reduce_max(select(valid, rdir.z, neg_inf)));
const float reduced_min_dist = reduce_min(select(valid, ray_tnear, vfloat<K>(pos_inf)));
const float reduced_max_dist = reduce_max(select(valid, ray_tfar , vfloat<K>(neg_inf)));
init(reduced_min_org, reduced_max_org, reduced_min_rdir, reduced_max_rdir, reduced_min_dist, reduced_max_dist, N);
}
__forceinline void init(const Vec3fa& reduced_min_org,
const Vec3fa& reduced_max_org,
const Vec3fa& reduced_min_rdir,
const Vec3fa& reduced_max_rdir,
float reduced_min_dist,
float reduced_max_dist,
int N)
{
const Vec3ba pos_rdir = ge_mask(reduced_min_rdir, Vec3fa(zero));
min_rdir = select(pos_rdir, reduced_min_rdir, reduced_max_rdir);
max_rdir = select(pos_rdir, reduced_max_rdir, reduced_min_rdir);
min_org_rdir = min_rdir * select(pos_rdir, reduced_max_org, reduced_min_org);
max_org_rdir = max_rdir * select(pos_rdir, reduced_min_org, reduced_max_org);
min_dist = reduced_min_dist;
max_dist = reduced_max_dist;
nf = NearFarPrecalculations(min_rdir, N);
}
template<int K>
__forceinline void updateMaxDist(const vfloat<K>& ray_tfar)
{
max_dist = reduce_max(ray_tfar);
}
NearFarPrecalculations nf;
Vec3fa min_rdir;
Vec3fa max_rdir;
Vec3fa min_org_rdir;
Vec3fa max_org_rdir;
float min_dist;
float max_dist;
};
typedef Frustum<false> FrustumFast;
/* Robust variant */
template<>
struct Frustum<true>
{
__forceinline Frustum() {}
template<int K>
__forceinline void init(const vbool<K>& valid, const Vec3vf<K>& org, const Vec3vf<K>& rdir, const vfloat<K>& ray_tnear, const vfloat<K>& ray_tfar, int N)
{
const Vec3fa reduced_min_org(reduce_min(select(valid, org.x, pos_inf)),
reduce_min(select(valid, org.y, pos_inf)),
reduce_min(select(valid, org.z, pos_inf)));
const Vec3fa reduced_max_org(reduce_max(select(valid, org.x, neg_inf)),
reduce_max(select(valid, org.y, neg_inf)),
reduce_max(select(valid, org.z, neg_inf)));
const Vec3fa reduced_min_rdir(reduce_min(select(valid, rdir.x, pos_inf)),
reduce_min(select(valid, rdir.y, pos_inf)),
reduce_min(select(valid, rdir.z, pos_inf)));
const Vec3fa reduced_max_rdir(reduce_max(select(valid, rdir.x, neg_inf)),
reduce_max(select(valid, rdir.y, neg_inf)),
reduce_max(select(valid, rdir.z, neg_inf)));
const float reduced_min_dist = reduce_min(select(valid, ray_tnear, vfloat<K>(pos_inf)));
const float reduced_max_dist = reduce_max(select(valid, ray_tfar , vfloat<K>(neg_inf)));
init(reduced_min_org, reduced_max_org, reduced_min_rdir, reduced_max_rdir, reduced_min_dist, reduced_max_dist, N);
}
__forceinline void init(const Vec3fa& reduced_min_org,
const Vec3fa& reduced_max_org,
const Vec3fa& reduced_min_rdir,
const Vec3fa& reduced_max_rdir,
float reduced_min_dist,
float reduced_max_dist,
int N)
{
const Vec3ba pos_rdir = ge_mask(reduced_min_rdir, Vec3fa(zero));
min_rdir = select(pos_rdir, reduced_min_rdir, reduced_max_rdir);
max_rdir = select(pos_rdir, reduced_max_rdir, reduced_min_rdir);
min_org = select(pos_rdir, reduced_max_org, reduced_min_org);
max_org = select(pos_rdir, reduced_min_org, reduced_max_org);
min_dist = reduced_min_dist;
max_dist = reduced_max_dist;
nf = NearFarPrecalculations(min_rdir, N);
}
template<int K>
__forceinline void updateMaxDist(const vfloat<K>& ray_tfar)
{
max_dist = reduce_max(ray_tfar);
}
NearFarPrecalculations nf;
Vec3fa min_rdir;
Vec3fa max_rdir;
Vec3fa min_org;
Vec3fa max_org;
float min_dist;
float max_dist;
};
typedef Frustum<true> FrustumRobust;
//////////////////////////////////////////////////////////////////////////////////////
// Fast AABBNode intersection
//////////////////////////////////////////////////////////////////////////////////////
template<int N>
__forceinline size_t intersectNodeFrustum(const typename BVHN<N>::AABBNode* __restrict__ node,
const FrustumFast& frustum, vfloat<N>& dist)
{
const vfloat<N> bminX = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.nearX);
const vfloat<N> bminY = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.nearY);
const vfloat<N> bminZ = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.nearZ);
const vfloat<N> bmaxX = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.farX);
const vfloat<N> bmaxY = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.farY);
const vfloat<N> bmaxZ = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.farZ);
const vfloat<N> fminX = msub(bminX, vfloat<N>(frustum.min_rdir.x), vfloat<N>(frustum.min_org_rdir.x));
const vfloat<N> fminY = msub(bminY, vfloat<N>(frustum.min_rdir.y), vfloat<N>(frustum.min_org_rdir.y));
const vfloat<N> fminZ = msub(bminZ, vfloat<N>(frustum.min_rdir.z), vfloat<N>(frustum.min_org_rdir.z));
const vfloat<N> fmaxX = msub(bmaxX, vfloat<N>(frustum.max_rdir.x), vfloat<N>(frustum.max_org_rdir.x));
const vfloat<N> fmaxY = msub(bmaxY, vfloat<N>(frustum.max_rdir.y), vfloat<N>(frustum.max_org_rdir.y));
const vfloat<N> fmaxZ = msub(bmaxZ, vfloat<N>(frustum.max_rdir.z), vfloat<N>(frustum.max_org_rdir.z));
const vfloat<N> fmin = maxi(fminX, fminY, fminZ, vfloat<N>(frustum.min_dist));
dist = fmin;
const vfloat<N> fmax = mini(fmaxX, fmaxY, fmaxZ, vfloat<N>(frustum.max_dist));
const vbool<N> vmask_node_hit = fmin <= fmax;
size_t m_node = movemask(vmask_node_hit) & (((size_t)1 << N)-1);
return m_node;
}
//////////////////////////////////////////////////////////////////////////////////////
// Robust AABBNode intersection
//////////////////////////////////////////////////////////////////////////////////////
template<int N>
__forceinline size_t intersectNodeFrustum(const typename BVHN<N>::AABBNode* __restrict__ node,
const FrustumRobust& frustum, vfloat<N>& dist)
{
const vfloat<N> bminX = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.nearX);
const vfloat<N> bminY = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.nearY);
const vfloat<N> bminZ = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.nearZ);
const vfloat<N> bmaxX = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.farX);
const vfloat<N> bmaxY = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.farY);
const vfloat<N> bmaxZ = *(const vfloat<N>*)((const char*)&node->lower_x + frustum.nf.farZ);
const vfloat<N> fminX = (bminX - vfloat<N>(frustum.min_org.x)) * vfloat<N>(frustum.min_rdir.x);
const vfloat<N> fminY = (bminY - vfloat<N>(frustum.min_org.y)) * vfloat<N>(frustum.min_rdir.y);
const vfloat<N> fminZ = (bminZ - vfloat<N>(frustum.min_org.z)) * vfloat<N>(frustum.min_rdir.z);
const vfloat<N> fmaxX = (bmaxX - vfloat<N>(frustum.max_org.x)) * vfloat<N>(frustum.max_rdir.x);
const vfloat<N> fmaxY = (bmaxY - vfloat<N>(frustum.max_org.y)) * vfloat<N>(frustum.max_rdir.y);
const vfloat<N> fmaxZ = (bmaxZ - vfloat<N>(frustum.max_org.z)) * vfloat<N>(frustum.max_rdir.z);
const float round_down = 1.0f-2.0f*float(ulp); // FIXME: use per instruction rounding for AVX512
const float round_up = 1.0f+2.0f*float(ulp);
const vfloat<N> fmin = max(fminX, fminY, fminZ, vfloat<N>(frustum.min_dist));
dist = fmin;
const vfloat<N> fmax = min(fmaxX, fmaxY, fmaxZ, vfloat<N>(frustum.max_dist));
const vbool<N> vmask_node_hit = (round_down*fmin <= round_up*fmax);
size_t m_node = movemask(vmask_node_hit) & (((size_t)1 << N)-1);
return m_node;
}
}
}
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