// Copyright 2009-2021 Intel Corporation // SPDX-License-Identifier: Apache-2.0 #pragma once #include "../common/ray.h" #include "quad_intersector.h" #include "curve_intersector_precalculations.h" #define Bezier1Intersector1 RibbonCurve1Intersector1 #define Bezier1IntersectorK RibbonCurve1IntersectorK namespace embree { namespace isa { template<typename NativeCurve3ff, int M> struct RibbonHit { __forceinline RibbonHit() {} __forceinline RibbonHit(const vbool<M>& valid, const vfloat<M>& U, const vfloat<M>& V, const vfloat<M>& T, const int i, const int N, const NativeCurve3ff& curve3D) : U(U), V(V), T(T), i(i), N(N), curve3D(curve3D), valid(valid) {} __forceinline void finalize() { vu = (vfloat<M>(step)+U+vfloat<M>(float(i)))*(1.0f/float(N)); vv = V; vt = T; } __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 curve3D.eval_du(vu[i]); } __forceinline Vec2vf<M> uv() const { return Vec2vf<M>(vu,vv); } __forceinline vfloat<M> t () const { return vt; } __forceinline Vec3vf<M> Ng() const { return (Vec3vf<M>) curve3D.template veval_du<M>(vu); } public: vfloat<M> U; vfloat<M> V; vfloat<M> T; int i, N; NativeCurve3ff curve3D; public: vbool<M> valid; vfloat<M> vu; vfloat<M> vv; vfloat<M> vt; }; /* calculate squared distance of point p0 to line p1->p2 */ __forceinline std::pair<vfloatx,vfloatx> sqr_point_line_distance(const Vec2vfx& p0, const Vec2vfx& p1, const Vec2vfx& p2) { const vfloatx num = det(p2-p1,p1-p0); const vfloatx den2 = dot(p2-p1,p2-p1); return std::make_pair(num*num,den2); } /* performs culling against a cylinder */ __forceinline vboolx cylinder_culling_test(const Vec2vfx& p0, const Vec2vfx& p1, const Vec2vfx& p2, const vfloatx& r) { const std::pair<vfloatx,vfloatx> d = sqr_point_line_distance(p0,p1,p2); return d.first <= r*r*d.second; } template<typename NativeCurve3ff, typename Epilog> __forceinline bool intersect_ribbon(const Vec3fa& ray_org, const Vec3fa& ray_dir, const float ray_tnear, const float& ray_tfar, const LinearSpace3fa& ray_space, const float& depth_scale, const NativeCurve3ff& curve3D, const int N, const Epilog& epilog) { /* transform control points into ray space */ const NativeCurve3ff curve2D = curve3D.xfm_pr(ray_space,ray_org); float eps = 4.0f*float(ulp)*reduce_max(max(abs(curve2D.v0),abs(curve2D.v1),abs(curve2D.v2),abs(curve2D.v3))); /* evaluate the bezier curve */ bool ishit = false; vboolx valid = vfloatx(step) < vfloatx(float(N)); const Vec4vfx p0 = curve2D.template eval0<VSIZEX>(0,N); const Vec4vfx p1 = curve2D.template eval1<VSIZEX>(0,N); valid &= cylinder_culling_test(zero,Vec2vfx(p0.x,p0.y),Vec2vfx(p1.x,p1.y),max(p0.w,p1.w)); if (any(valid)) { Vec3vfx dp0dt = curve2D.template derivative0<VSIZEX>(0,N); Vec3vfx dp1dt = curve2D.template derivative1<VSIZEX>(0,N); dp0dt = select(reduce_max(abs(dp0dt)) < vfloatx(eps),Vec3vfx(p1-p0),dp0dt); dp1dt = select(reduce_max(abs(dp1dt)) < vfloatx(eps),Vec3vfx(p1-p0),dp1dt); const Vec3vfx n0(dp0dt.y,-dp0dt.x,0.0f); const Vec3vfx n1(dp1dt.y,-dp1dt.x,0.0f); const Vec3vfx nn0 = normalize(n0); const Vec3vfx nn1 = normalize(n1); const Vec3vfx lp0 = madd(p0.w,nn0,Vec3vfx(p0)); const Vec3vfx lp1 = madd(p1.w,nn1,Vec3vfx(p1)); const Vec3vfx up0 = nmadd(p0.w,nn0,Vec3vfx(p0)); const Vec3vfx up1 = nmadd(p1.w,nn1,Vec3vfx(p1)); vfloatx vu,vv,vt; vboolx valid0 = intersect_quad_backface_culling<VSIZEX>(valid,zero,Vec3fa(0,0,1),ray_tnear,ray_tfar,lp0,lp1,up1,up0,vu,vv,vt); if (any(valid0)) { /* ignore self intersections */ if (EMBREE_CURVE_SELF_INTERSECTION_AVOIDANCE_FACTOR != 0.0f) { vfloatx r = lerp(p0.w, p1.w, vu); valid0 &= vt > float(EMBREE_CURVE_SELF_INTERSECTION_AVOIDANCE_FACTOR)*r*depth_scale; } if (any(valid0)) { vv = madd(2.0f,vv,vfloatx(-1.0f)); RibbonHit<NativeCurve3ff,VSIZEX> bhit(valid0,vu,vv,vt,0,N,curve3D); ishit |= epilog(bhit.valid,bhit); } } } if (unlikely(VSIZEX < N)) { /* process SIMD-size many segments per iteration */ for (int i=VSIZEX; i<N; i+=VSIZEX) { /* evaluate the bezier curve */ vboolx valid = vintx(i)+vintx(step) < vintx(N); const Vec4vfx p0 = curve2D.template eval0<VSIZEX>(i,N); const Vec4vfx p1 = curve2D.template eval1<VSIZEX>(i,N); valid &= cylinder_culling_test(zero,Vec2vfx(p0.x,p0.y),Vec2vfx(p1.x,p1.y),max(p0.w,p1.w)); if (none(valid)) continue; Vec3vfx dp0dt = curve2D.template derivative0<VSIZEX>(i,N); Vec3vfx dp1dt = curve2D.template derivative1<VSIZEX>(i,N); dp0dt = select(reduce_max(abs(dp0dt)) < vfloatx(eps),Vec3vfx(p1-p0),dp0dt); dp1dt = select(reduce_max(abs(dp1dt)) < vfloatx(eps),Vec3vfx(p1-p0),dp1dt); const Vec3vfx n0(dp0dt.y,-dp0dt.x,0.0f); const Vec3vfx n1(dp1dt.y,-dp1dt.x,0.0f); const Vec3vfx nn0 = normalize(n0); const Vec3vfx nn1 = normalize(n1); const Vec3vfx lp0 = madd(p0.w,nn0,Vec3vfx(p0)); const Vec3vfx lp1 = madd(p1.w,nn1,Vec3vfx(p1)); const Vec3vfx up0 = nmadd(p0.w,nn0,Vec3vfx(p0)); const Vec3vfx up1 = nmadd(p1.w,nn1,Vec3vfx(p1)); vfloatx vu,vv,vt; vboolx valid0 = intersect_quad_backface_culling<VSIZEX>(valid,zero,Vec3fa(0,0,1),ray_tnear,ray_tfar,lp0,lp1,up1,up0,vu,vv,vt); if (any(valid0)) { /* ignore self intersections */ if (EMBREE_CURVE_SELF_INTERSECTION_AVOIDANCE_FACTOR != 0.0f) { vfloatx r = lerp(p0.w, p1.w, vu); valid0 &= vt > float(EMBREE_CURVE_SELF_INTERSECTION_AVOIDANCE_FACTOR)*r*depth_scale; } if (any(valid0)) { vv = madd(2.0f,vv,vfloatx(-1.0f)); RibbonHit<NativeCurve3ff,VSIZEX> bhit(valid0,vu,vv,vt,i,N,curve3D); ishit |= epilog(bhit.valid,bhit); } } } } return ishit; } template<template<typename Ty> class NativeCurve> struct RibbonCurve1Intersector1 { typedef NativeCurve<Vec3ff> NativeCurve3ff; template<typename Epilog> __forceinline bool intersect(const CurvePrecalculations1& pre, Ray& ray, IntersectContext* context, const CurveGeometry* geom, const unsigned int primID, const Vec3ff& v0, const Vec3ff& v1, const Vec3ff& v2, const Vec3ff& v3, const Epilog& epilog) { const int N = geom->tessellationRate; NativeCurve3ff curve(v0,v1,v2,v3); curve = enlargeRadiusToMinWidth(context,geom,ray.org,curve); return intersect_ribbon<NativeCurve3ff>(ray.org,ray.dir,ray.tnear(),ray.tfar, pre.ray_space,pre.depth_scale, curve,N, epilog); } }; template<template<typename Ty> class NativeCurve, int K> struct RibbonCurve1IntersectorK { typedef NativeCurve<Vec3ff> NativeCurve3ff; template<typename Epilog> __forceinline bool intersect(const CurvePrecalculationsK<K>& pre, RayK<K>& ray, size_t k, IntersectContext* context, const CurveGeometry* geom, const unsigned int primID, const Vec3ff& v0, const Vec3ff& v1, const Vec3ff& v2, const Vec3ff& v3, const Epilog& epilog) { const int N = geom->tessellationRate; const Vec3fa ray_org(ray.org.x[k],ray.org.y[k],ray.org.z[k]); const Vec3fa ray_dir(ray.dir.x[k],ray.dir.y[k],ray.dir.z[k]); NativeCurve3ff curve(v0,v1,v2,v3); curve = enlargeRadiusToMinWidth(context,geom,ray_org,curve); return intersect_ribbon<NativeCurve3ff>(ray_org,ray_dir,ray.tnear()[k],ray.tfar[k], pre.ray_space[k],pre.depth_scale[k], curve,N, epilog); } }; } }