DetectorGroup.cpp

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// Mantid Repository : https://github.com/mantidproject/mantid
//
// Copyright © 2018 ISIS Rutherford Appleton Laboratory UKRI,
//   NScD Oak Ridge National Laboratory, European Spallation Source,
//   Institut Laue - Langevin & CSNS, Institute of High Energy Physics, CAS
// SPDX - License - Identifier: GPL - 3.0 +
#include "MantidGeometry/Instrument/DetectorGroup.h"
#include "MantidGeometry/Instrument/ComponentVisitor.h"
#include "MantidGeometry/Objects/BoundingBox.h"
#include "MantidKernel/Exception.h"
#include "MantidKernel/Logger.h"
#include "MantidKernel/Material.h"
#include "MantidKernel/V2D.h"
 
#include <numeric>
 
namespace Mantid::Geometry {
namespace {
// static logger
Kernel::Logger g_log("DetectorGroup");
} // namespace
 
using Kernel::Quat;
using Kernel::V2D;
using Kernel::V3D;
 
DetectorGroup::DetectorGroup() : IDetector(), m_id(), m_detectors(), group_topology(undef) {}
 
DetectorGroup::DetectorGroup(const std::vector<IDetector_const_sptr> &dets)
    : IDetector(), m_id(), m_detectors(), group_topology(undef) {
  if (dets.empty()) {
    g_log.error("Illegal attempt to create an empty DetectorGroup");
    throw std::invalid_argument("Empty DetectorGroup objects are not allowed");
  }
  std::vector<IDetector_const_sptr>::const_iterator it;
  for (it = dets.begin(); it != dets.end(); ++it) {
    addDetector(*it);
  }
}
 
void DetectorGroup::addDetector(const IDetector_const_sptr &det) {
  // the topology of the group become undefined and needs recalculation if new
  // detector has been added to the group
  group_topology = undef;
 
  // For now at least, the ID is the same as the first detector that is added
  if (m_detectors.empty())
    m_id = det->getID();
 
  m_detectors.insert(DetCollection::value_type(det->getID(), det));
}
 
detid_t DetectorGroup::getID() const { return m_id; }
 
std::size_t DetectorGroup::nDets() const { return m_detectors.size(); }
 
V3D DetectorGroup::getPos() const {
  V3D newPos = std::accumulate(m_detectors.cbegin(), m_detectors.cend(), V3D(),
                               [](const V3D &pos, const auto &detector) { return pos + detector.second->getPos(); });
 
  // We can have very small values (< Tolerance) of each component that should
  // be zero
  if (std::abs(newPos[0]) < Mantid::Kernel::Tolerance)
    newPos[0] = 0.0;
  if (std::abs(newPos[1]) < Mantid::Kernel::Tolerance)
    newPos[1] = 0.0;
  if (std::abs(newPos[2]) < Mantid::Kernel::Tolerance)
    newPos[2] = 0.0;
 
  return newPos /= static_cast<double>(m_detectors.size()); // protection against divide by zero in V3D
}
 
std::optional<Kernel::V2D> DetectorGroup::getSideBySideViewPos() const { return std::nullopt; }
 
double DetectorGroup::getDistance(const IComponent &comp) const {
  double result =
      std::accumulate(m_detectors.cbegin(), m_detectors.cend(), 0.0,
                      [&comp](double sum, const auto &detector) { return sum + detector.second->getDistance(comp); });
  return result / static_cast<double>(m_detectors.size());
}
 
double DetectorGroup::getTwoTheta(const V3D &observer, const V3D &axis) const {
  double result = 0.0;
  DetCollection::const_iterator it;
  for (it = m_detectors.begin(); it != m_detectors.end(); ++it) {
    const V3D sampleDetVec = (*it).second->getPos() - observer;
    result += sampleDetVec.angle(axis);
  }
  return result / static_cast<double>(m_detectors.size());
}
 
/*
Gives the average angle of a group of detectors from the observation point,
relative to the axis given.
Returned values are signed according to the rotation direction relative to the
axis and the instrument up direction.
@param observer : observer (usually sample)
@param axis : scattering axis.
@param instrumentUp : Instrument up direction
@return signed theta
*/
double DetectorGroup::getSignedTwoTheta(const Kernel::V3D &observer, const Kernel::V3D &axis,
                                        const Kernel::V3D &instrumentUp) const {
  double result = 0.0;
  DetCollection::const_iterator it;
  for (it = m_detectors.begin(); it != m_detectors.end(); ++it) {
    const V3D sampleDetVec = it->second->getPos() - observer;
    double angle = sampleDetVec.angle(axis);
 
    V3D cross = axis.cross_prod(sampleDetVec);
    V3D normToSurface = axis.cross_prod(instrumentUp);
    if (normToSurface.scalar_prod(cross) < 0) {
      angle *= -1;
    }
    result += angle;
  }
  return result / static_cast<double>(m_detectors.size());
}
 
double DetectorGroup::getPhi() const {
  V3D avgPos = this->getPos();
  double phi(0.0), dummy1(0.0), dummy2(0.0);
  avgPos.getSpherical(dummy1, dummy2, phi);
  return phi * M_PI / 180.0;
}
 
double DetectorGroup::getPhiOffset(const double &offset) const {
  double avgPos = getPhi();
  return avgPos < 0 ? -(offset + avgPos) : offset - avgPos;
}
 
std::vector<detid_t> DetectorGroup::getDetectorIDs() const {
  std::vector<detid_t> result;
  result.reserve(m_detectors.size());
  DetCollection::const_iterator it;
  for (it = m_detectors.begin(); it != m_detectors.end(); ++it) {
    result.emplace_back((*it).first);
  }
  return result;
}
 
std::vector<IDetector_const_sptr> DetectorGroup::getDetectors() const {
  std::vector<IDetector_const_sptr> result;
  result.reserve(m_detectors.size());
  DetCollection::const_iterator it;
  for (it = m_detectors.begin(); it != m_detectors.end(); ++it) {
    result.emplace_back((*it).second);
  }
  return result;
}
 
double DetectorGroup::solidAngle(const Geometry::SolidAngleParams &params) const {
  double result =
      std::accumulate(m_detectors.cbegin(), m_detectors.cend(), 0.0,
                      [&params](double angle, const auto &det) { return angle + det.second->solidAngle(params); });
  return result;
}
 
bool DetectorGroup::isParametrized() const {
  return std::any_of(m_detectors.cbegin(), m_detectors.cend(),
                     [](const auto &detector) { return detector.second->isParametrized(); });
}
 
bool DetectorGroup::isValid(const V3D &point) const {
  return std::any_of(m_detectors.cbegin(), m_detectors.cend(),
                     [&point](const auto &detector) { return detector.second->isValid(point); });
}
 
bool DetectorGroup::isOnSide(const V3D &point) const {
  return std::any_of(m_detectors.cbegin(), m_detectors.cend(),
                     [&point](const auto &detector) { return detector.second->isOnSide(point); });
}
 
int DetectorGroup::getPointInObject(V3D &point) const {
  DetCollection::const_iterator it;
  it = m_detectors.begin();
  if (it == m_detectors.end())
    return 0;
  return (*m_detectors.begin()).second->getPointInObject(point);
}
 
std::set<std::string> DetectorGroup::getParameterNames(bool recursive) const {
  (void)recursive; // Avoid compiler warning
  return std::set<std::string>();
}
 
std::string DetectorGroup::getParameterAsString(const std::string &pname, bool recursive) const {
  (void)pname;     // Avoid compiler warning
  (void)recursive; // Avoid compiler warning
  return "";
}
 
bool DetectorGroup::getParameterVisible(const std::string &pname, bool recursive) const {
  (void)pname;     // Avoid compiler warning
  (void)recursive; // Avoid compiler warning
  return false;
}
 
void DetectorGroup::getBoundingBox(BoundingBox &boundingBox) const {
  // boundingBox = BoundingBox(); // this change may modify a lot of behaviour
  // -> verify
  for (const auto &detector : m_detectors) {
    BoundingBox memberBox;
    if (!boundingBox.isAxisAligned()) {
      // coordinate system
      const std::vector<V3D> *cs = &(boundingBox.getCoordSystem());
      memberBox.realign(cs);
    }
    detector.second->getBoundingBox(memberBox);
    boundingBox.grow(memberBox);
  }
}
bool DetectorGroup::hasParameter(const std::string &name, bool recursive) const {
  (void)recursive; // Avoid compiler warning
  (void)name;      // Avoid compiler warning
  return false;
}
std::string DetectorGroup::getParameterType(const std::string & /*name*/, bool /*recursive = true*/) const {
  return std::string("");
}
 
std::vector<double> DetectorGroup::getNumberParameter(const std::string & /*pname*/, bool /*recursive*/) const {
  return std::vector<double>(0);
}
 
std::vector<V3D> DetectorGroup::getPositionParameter(const std::string & /*pname*/, bool /*recursive*/) const {
  return std::vector<V3D>(0);
}
 
std::vector<Quat> DetectorGroup::getRotationParameter(const std::string & /*pname*/, bool /*recursive*/) const {
  return std::vector<Quat>(0);
}
 
std::vector<std::string> DetectorGroup::getStringParameter(const std::string & /*pname*/, bool /*recursive*/) const {
  return std::vector<std::string>(0);
}
 
std::vector<int> DetectorGroup::getIntParameter(const std::string & /*pname*/, bool /*recursive*/) const {
  return std::vector<int>(0);
}
 
std::vector<bool> DetectorGroup::getBoolParameter(const std::string & /*pname*/, bool /*recursive*/) const {
  return std::vector<bool>(0);
}
 
det_topology DetectorGroup::getTopology(V3D &center) const {
  if (group_topology == undef) {
    this->calculateGroupTopology();
  }
  center = this->groupCentre;
  return group_topology;
}
void DetectorGroup::calculateGroupTopology() const {
  if (m_detectors.size() == 1) {
    group_topology = rect;
 
    return;
  }
  this->groupCentre = this->getPos();
  if (this->isValid(groupCentre)) {
    group_topology = rect;
  } else {
    // the topology can still be rectangular, but randomisation errors or small
    // gaps between
    // detectors caused central point not to belong to detectors; need more
    // accrurate estinations
    // assuming that distance between detectors can not be bigger then
    // detector's half size
    // get detector's size:
    IDetector_const_sptr spFirstDet = this->m_detectors.begin()->second;
 
    BoundingBox bbox;
    spFirstDet->getBoundingBox(bbox);
    V3D width = bbox.width();
 
    // loop if any near point belongs to group;
    for (int i = 0; i < 6; i++) {
      int ic = int(i) / 2;
      int is = (i % 2 == 0) ? -1 : 1;
      V3D cs = groupCentre;
      cs[ic] += is * width[ic] / 4;
      if (this->isValid(cs)) { // if it is, finish and end
        group_topology = rect;
        break;
      }
    }
    // if not, consider this group to be a ring;
    if (this->group_topology == undef) {
      group_topology = cyl;
    }
  }
}
 
std::string DetectorGroup::getName() const {
  std::string result;
  DetCollection::const_iterator it;
  for (it = m_detectors.begin(); it != m_detectors.end(); ++it) {
    result += (*it).second->getName() + this->getNameSeparator();
  }
  return result;
}
 
std::string DetectorGroup::getFullName() const {
  std::string result;
  DetCollection::const_iterator it;
  for (it = m_detectors.begin(); it != m_detectors.end(); ++it) {
    result += (*it).second->getFullName() + this->getNameSeparator();
  }
  return result;
}
 
const Kernel::Material DetectorGroup::material() const { return Kernel::Material(); }
 
const ParameterMap &DetectorGroup::parameterMap() const {
  throw std::runtime_error("A DetectorGroup cannot have a ParameterMap");
}
 
size_t DetectorGroup::index() const { throw std::runtime_error("A DetectorGroup cannot have an index"); }
 
size_t DetectorGroup::registerContents(class ComponentVisitor & /*component*/) const {
  throw std::runtime_error("DetectorGroup::registerContents. This should not "
                           "be called. DetectorGroups are not part of the "
                           "instrument. On-the-fly only.");
}
 
} // namespace Mantid::Geometry