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

223 lines
8.2 KiB
C++

// Copyright 2009-2020 Intel Corporation
// SPDX-License-Identifier: Apache-2.0
#pragma once
#include "../common/ray.h"
namespace embree
{
namespace isa
{
struct Cylinder
{
const Vec3fa p0; //!< start location
const Vec3fa p1; //!< end position
const float rr; //!< squared radius of cylinder
__forceinline Cylinder(const Vec3fa& p0, const Vec3fa& p1, const float r)
: p0(p0), p1(p1), rr(sqr(r)) {}
__forceinline Cylinder(const Vec3fa& p0, const Vec3fa& p1, const float rr, bool)
: p0(p0), p1(p1), rr(rr) {}
__forceinline bool intersect(const Vec3fa& org,
const Vec3fa& dir,
BBox1f& t_o,
float& u0_o, Vec3fa& Ng0_o,
float& u1_o, Vec3fa& Ng1_o) const
{
/* calculate quadratic equation to solve */
const float rl = rcp_length(p1-p0);
const Vec3fa P0 = p0, dP = (p1-p0)*rl;
const Vec3fa O = org-P0, dO = dir;
const float dOdO = dot(dO,dO);
const float OdO = dot(dO,O);
const float OO = dot(O,O);
const float dOz = dot(dP,dO);
const float Oz = dot(dP,O);
const float A = dOdO - sqr(dOz);
const float B = 2.0f * (OdO - dOz*Oz);
const float C = OO - sqr(Oz) - rr;
/* we miss the cylinder if determinant is smaller than zero */
const float D = B*B - 4.0f*A*C;
if (D < 0.0f) {
t_o = BBox1f(pos_inf,neg_inf);
return false;
}
/* special case for rays that are parallel to the cylinder */
const float eps = 16.0f*float(ulp)*max(abs(dOdO),abs(sqr(dOz)));
if (abs(A) < eps)
{
if (C <= 0.0f) {
t_o = BBox1f(neg_inf,pos_inf);
return true;
} else {
t_o = BBox1f(pos_inf,neg_inf);
return false;
}
}
/* standard case for rays that are not parallel to the cylinder */
const float Q = sqrt(D);
const float rcp_2A = rcp(2.0f*A);
const float t0 = (-B-Q)*rcp_2A;
const float t1 = (-B+Q)*rcp_2A;
/* calculates u and Ng for near hit */
{
u0_o = madd(t0,dOz,Oz)*rl;
const Vec3fa Pr = t0*dir;
const Vec3fa Pl = madd(u0_o,p1-p0,p0);
Ng0_o = Pr-Pl;
}
/* calculates u and Ng for far hit */
{
u1_o = madd(t1,dOz,Oz)*rl;
const Vec3fa Pr = t1*dir;
const Vec3fa Pl = madd(u1_o,p1-p0,p0);
Ng1_o = Pr-Pl;
}
t_o.lower = t0;
t_o.upper = t1;
return true;
}
__forceinline bool intersect(const Vec3fa& org_i, const Vec3fa& dir, BBox1f& t_o) const
{
float u0_o; Vec3fa Ng0_o;
float u1_o; Vec3fa Ng1_o;
return intersect(org_i,dir,t_o,u0_o,Ng0_o,u1_o,Ng1_o);
}
static bool verify(const size_t id, const Cylinder& cylinder, const RayHit& ray, bool shouldhit, const float t0, const float t1)
{
float eps = 0.001f;
BBox1f t; bool hit;
hit = cylinder.intersect(ray.org,ray.dir,t);
bool failed = hit != shouldhit;
if (shouldhit) failed |= std::isinf(t0) ? t0 != t.lower : abs(t0-t.lower) > eps;
if (shouldhit) failed |= std::isinf(t1) ? t1 != t.upper : abs(t1-t.upper) > eps;
if (!failed) return true;
embree_cout << "Cylinder test " << id << " failed: cylinder = " << cylinder << ", ray = " << ray << ", hit = " << hit << ", t = " << t << embree_endl;
return false;
}
/* verify cylinder class */
static bool verify()
{
bool passed = true;
const Cylinder cylinder(Vec3fa(0.0f,0.0f,0.0f),Vec3fa(1.0f,0.0f,0.0f),1.0f);
passed &= verify(0,cylinder,RayHit(Vec3fa(-2.0f,1.0f,0.0f),Vec3fa( 0.0f,-1.0f,+0.0f),0.0f,float(inf)),true,0.0f,2.0f);
passed &= verify(1,cylinder,RayHit(Vec3fa(+2.0f,1.0f,0.0f),Vec3fa( 0.0f,-1.0f,+0.0f),0.0f,float(inf)),true,0.0f,2.0f);
passed &= verify(2,cylinder,RayHit(Vec3fa(+2.0f,1.0f,2.0f),Vec3fa( 0.0f,-1.0f,+0.0f),0.0f,float(inf)),false,0.0f,0.0f);
passed &= verify(3,cylinder,RayHit(Vec3fa(+0.0f,0.0f,0.0f),Vec3fa( 1.0f, 0.0f,+0.0f),0.0f,float(inf)),true,neg_inf,pos_inf);
passed &= verify(4,cylinder,RayHit(Vec3fa(+0.0f,0.0f,0.0f),Vec3fa(-1.0f, 0.0f,+0.0f),0.0f,float(inf)),true,neg_inf,pos_inf);
passed &= verify(5,cylinder,RayHit(Vec3fa(+0.0f,2.0f,0.0f),Vec3fa( 1.0f, 0.0f,+0.0f),0.0f,float(inf)),false,pos_inf,neg_inf);
passed &= verify(6,cylinder,RayHit(Vec3fa(+0.0f,2.0f,0.0f),Vec3fa(-1.0f, 0.0f,+0.0f),0.0f,float(inf)),false,pos_inf,neg_inf);
return passed;
}
/*! output operator */
friend __forceinline embree_ostream operator<<(embree_ostream cout, const Cylinder& c) {
return cout << "Cylinder { p0 = " << c.p0 << ", p1 = " << c.p1 << ", r = " << sqrtf(c.rr) << "}";
}
};
template<int N>
struct CylinderN
{
const Vec3vf<N> p0; //!< start location
const Vec3vf<N> p1; //!< end position
const vfloat<N> rr; //!< squared radius of cylinder
__forceinline CylinderN(const Vec3vf<N>& p0, const Vec3vf<N>& p1, const vfloat<N>& r)
: p0(p0), p1(p1), rr(sqr(r)) {}
__forceinline CylinderN(const Vec3vf<N>& p0, const Vec3vf<N>& p1, const vfloat<N>& rr, bool)
: p0(p0), p1(p1), rr(rr) {}
__forceinline vbool<N> intersect(const Vec3fa& org, const Vec3fa& dir,
BBox<vfloat<N>>& t_o,
vfloat<N>& u0_o, Vec3vf<N>& Ng0_o,
vfloat<N>& u1_o, Vec3vf<N>& Ng1_o) const
{
/* calculate quadratic equation to solve */
const vfloat<N> rl = rcp_length(p1-p0);
const Vec3vf<N> P0 = p0, dP = (p1-p0)*rl;
const Vec3vf<N> O = Vec3vf<N>(org)-P0, dO = dir;
const vfloat<N> dOdO = dot(dO,dO);
const vfloat<N> OdO = dot(dO,O);
const vfloat<N> OO = dot(O,O);
const vfloat<N> dOz = dot(dP,dO);
const vfloat<N> Oz = dot(dP,O);
const vfloat<N> A = dOdO - sqr(dOz);
const vfloat<N> B = 2.0f * (OdO - dOz*Oz);
const vfloat<N> C = OO - sqr(Oz) - rr;
/* we miss the cylinder if determinant is smaller than zero */
const vfloat<N> D = B*B - 4.0f*A*C;
vbool<N> valid = D >= 0.0f;
if (none(valid)) {
t_o = BBox<vfloat<N>>(empty);
return valid;
}
/* standard case for rays that are not parallel to the cylinder */
const vfloat<N> Q = sqrt(D);
const vfloat<N> rcp_2A = rcp(2.0f*A);
const vfloat<N> t0 = (-B-Q)*rcp_2A;
const vfloat<N> t1 = (-B+Q)*rcp_2A;
/* calculates u and Ng for near hit */
{
u0_o = madd(t0,dOz,Oz)*rl;
const Vec3vf<N> Pr = t0*Vec3vf<N>(dir);
const Vec3vf<N> Pl = madd(u0_o,p1-p0,p0);
Ng0_o = Pr-Pl;
}
/* calculates u and Ng for far hit */
{
u1_o = madd(t1,dOz,Oz)*rl;
const Vec3vf<N> Pr = t1*Vec3vf<N>(dir);
const Vec3vf<N> Pl = madd(u1_o,p1-p0,p0);
Ng1_o = Pr-Pl;
}
t_o.lower = select(valid, t0, vfloat<N>(pos_inf));
t_o.upper = select(valid, t1, vfloat<N>(neg_inf));
/* special case for rays that are parallel to the cylinder */
const vfloat<N> eps = 16.0f*float(ulp)*max(abs(dOdO),abs(sqr(dOz)));
vbool<N> validt = valid & (abs(A) < eps);
if (unlikely(any(validt)))
{
vbool<N> inside = C <= 0.0f;
t_o.lower = select(validt,select(inside,vfloat<N>(neg_inf),vfloat<N>(pos_inf)),t_o.lower);
t_o.upper = select(validt,select(inside,vfloat<N>(pos_inf),vfloat<N>(neg_inf)),t_o.upper);
valid &= !validt | inside;
}
return valid;
}
__forceinline vbool<N> intersect(const Vec3fa& org_i, const Vec3fa& dir, BBox<vfloat<N>>& t_o) const
{
vfloat<N> u0_o; Vec3vf<N> Ng0_o;
vfloat<N> u1_o; Vec3vf<N> Ng1_o;
return intersect(org_i,dir,t_o,u0_o,Ng0_o,u1_o,Ng1_o);
}
};
}
}