initial commit, 4.5 stable

thirdparty/embree/kernels/geometry/sphere_intersector.h

@@ -0,0 +1,235 @@
+// Copyright 2009-2021 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 Vec2vf<M> uv() const {
+        return Vec2vf<M>(0.0f, 0.0f);
+      }
+      __forceinline float t(const size_t i) const {
+        return vt[i];
+      }
+      __forceinline vfloat<M> t() const {
+        return vt;
+      }
+      __forceinline Vec3fa Ng(const size_t i) const {
+        return Vec3fa(vNg.x[i], vNg.y[i], vNg.z[i]);
+      }
+      __forceinline Vec3vf<M> Ng() const { 
+        return vNg;
+      }
+
+     public:
+      vfloat<M> vt;
+      Vec3vf<M> vNg;
+    };
+
+    template<>
+    struct SphereIntersectorHitM<1>
+    {
+      __forceinline SphereIntersectorHitM() {}
+
+      __forceinline SphereIntersectorHitM(const float& t, const Vec3f& Ng)
+        : vt(t), vNg(Ng) {}
+
+      __forceinline void finalize() {}
+
+      __forceinline Vec2f uv() const {
+        return Vec2f(0.0f, 0.0f);
+      }
+
+      __forceinline float t() const {
+        return vt;
+      }
+
+      __forceinline Vec3f Ng() const { 
+        return vNg;
+      }
+
+     public:
+      float vt;
+      Vec3f vNg;
+    };
+
+    template<int M>
+    struct SphereIntersector1
+    {
+      typedef CurvePrecalculations1 Precalculations;
+
+      template<typename Ray, 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);
+
+        /* check if there is a first hit */
+#if defined (EMBREE_BACKFACE_CULLING_SPHERES)
+        /* check if there is a first hit */
+        const vbool<M> valid_first = valid_front;
+#else
+        const vbool<M> valid_back  = valid & (ray.tnear() <= t_back ) & (t_back  <= ray.tfar);
+        const vbool<M> valid_first = valid_front | valid_back;
+#endif
+        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);
+
+#if defined (EMBREE_BACKFACE_CULLING_SPHERES)
+        return is_hit_first;
+#else
+        /* 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;
+#endif
+      }
+
+      template<typename Epilog>
+      static __forceinline bool intersect(
+        const vbool<M>& valid_i, Ray& ray, RayQueryContext* 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<M>(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,
+                                          RayQueryContext* 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<M>(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]);
+
+        /* check if there is a first hit */
+#if defined (EMBREE_BACKFACE_CULLING_SPHERES)
+        const vbool<M> valid_first = valid_front;
+#else
+        const vbool<M> valid_back  = valid & (ray.tnear()[k] <= t_back ) & (t_back  <= ray.tfar[k]);
+        const vbool<M> valid_first = valid_front | valid_back;
+#endif
+        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);
+
+#if defined (EMBREE_BACKFACE_CULLING_SPHERES)
+        return is_hit_first;
+#else
+        /* 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;
+#endif
+      }
+    };
+  }  // namespace isa
+}  // namespace embree