Function sphereIntersectFunc

tutorials/user_geometry/user_geometry_device.cpp:269–375

}

RTC_SYCL_INDIRECTLY_CALLABLE void sphereIntersectFunc(const RTCIntersectFunctionNArguments* args)
{
  int* valid = args->valid;
  void* ptr  = args->geometryUserPtr;
  Ray *ray = (Ray*)args->rayhit;
  RTCHit* hit = (RTCHit *)&ray->Ng.x;
  unsigned int primID = args->primID;
  
  assert(args->N == 1);
  const Sphere* spheres = (const Sphere*)ptr;
  const Sphere& sphere = spheres[primID];
  
  if (!valid[0]) return;
  valid[0] = 0;

  const Vec3fa v = ray->org-sphere.p;
  const float A = dot(ray->dir,ray->dir);
  const float B = 2.0f*dot(v,ray->dir);
  const float C = dot(v,v) - sqr(sphere.r);
  const float D = B*B - 4.0f*A*C;
  if (D < 0.0f) return;
  const float Q = sqrt(D);
  const float rcpA = rcp(A);
  const float t0 = 0.5f*rcpA*(-B-Q);
  const float t1 = 0.5f*rcpA*(-B+Q);

  RTCHit potentialHit;
  potentialHit.u = 0.0f;
  potentialHit.v = 0.0f;
  copyInstanceIdStack(args->context, potentialHit.instID);
  potentialHit.geomID = sphere.geomID;
  potentialHit.primID = primID;

  if ((ray->tnear() < t0) & (t0 < ray->tfar))
  {
    int imask;
    bool mask = 1;
    {
      imask = mask ? -1 : 0;
    }
    
    const Vec3fa Ng = ray->org+t0*ray->dir-sphere.p;
    potentialHit.Ng_x = Ng.x;
    potentialHit.Ng_y = Ng.y;
    potentialHit.Ng_z = Ng.z;

    RTCFilterFunctionNArguments fargs;
    fargs.valid = (int*)&imask;
    fargs.geometryUserPtr = ptr;
    fargs.context = args->context;
    fargs.ray = (RTCRayN *)args->rayhit;
    fargs.hit = (RTCHitN*)&potentialHit;
    fargs.N = 1;

    const float old_t = ray->tfar;
    ray->tfar = t0;
#if USE_ARGUMENT_CALLBACKS
    contextFilterFunction(&fargs);