35373 support for collimator in DiscusMultipleScatteringCorrection algorithm

Framework/Algorithms/inc/MantidAlgorithms/DiscusMultipleScatteringCorrection.h

@@ -16,9 +16,10 @@
 #include "MantidAlgorithms/SampleCorrections/SparseWorkspace.h"
 #include "MantidGeometry/IComponent.h"
 #include "MantidGeometry/Instrument/SampleEnvironment.h"
+#include "MantidGeometry/Objects/CSGObject.h"
 #include "MantidKernel/PseudoRandomNumberGenerator.h"
-
 #include <boost/container/small_vector.hpp>
+#include <shared_mutex>
 
 namespace Mantid {
 namespace API {
@@ -69,6 +70,15 @@ struct ComponentWorkspaceMapping {
   std::shared_ptr<int> scatterCount = std::make_shared<int>(0);
 };
 
+/** Object for holding collimator parameteres loaded from instrument parameters file
+ */
+struct CollimatorInfo {
+  double m_innerRadius;
+  double m_halfAngularExtent;
+  double m_plateHeight;
+  Kernel::V3D m_axisVec;
+};
+
 /** Calculates a multiple scattering correction
 * Based on Muscat Fortran code provided by Spencer Howells
 
@@ -112,6 +122,9 @@ class MANTID_ALGORITHMS_DLL DiscusMultipleScatteringCorrection : public API::Alg
   API::MatrixWorkspace_sptr integrateWS(const API::MatrixWorkspace_sptr &ws);
   void getXMinMax(const Mantid::API::MatrixWorkspace &ws, double &xmin, double &xmax) const;
   void prepareSampleBeamGeometry(const API::MatrixWorkspace_sptr &inputWS);
+  const std::shared_ptr<Geometry::CSGObject>
+  createCollimatorHexahedronShape(const Kernel::V3D &samplePos, const Mantid::Geometry::DetectorInfo &detectorInfo,
+                                  const size_t &histogramIndex);
 
 private:
   void init() override;
@@ -122,11 +135,15 @@ class MANTID_ALGORITHMS_DLL DiscusMultipleScatteringCorrection : public API::Alg
   std::tuple<std::vector<double>, std::vector<double>>
   simulatePaths(const int nEvents, const int nScatters, Kernel::PseudoRandomNumberGenerator &rng,
                 const ComponentWorkspaceMappings &componentWorkspaces, const double kinc,
-                const std::vector<double> &wValues, const Kernel::V3D &detPos, bool specialSingleScatterCalc);
+                const std::vector<double> &wValues, bool specialSingleScatterCalc,
+                const Mantid::Geometry::DetectorInfo &detectorInfo, const size_t &histogramIndex);
   std::tuple<bool, std::vector<double>> scatter(const int nScatters, Kernel::PseudoRandomNumberGenerator &rng,
                                                 const ComponentWorkspaceMappings &componentWorkspaces,
                                                 const double kinc, const std::vector<double> &wValues,
-                                                const Kernel::V3D &detPos, bool specialSingleScatterCalc);
+                                                bool specialSingleScatterCalc,
+                                                const Mantid::Geometry::DetectorInfo &detectorInfo,
+                                                const size_t &histogramIndex);
+
   Geometry::Track start_point(Kernel::PseudoRandomNumberGenerator &rng);
   Geometry::Track generateInitialTrack(Kernel::PseudoRandomNumberGenerator &rng);
   void inc_xyz(Geometry::Track &track, double vl);
@@ -160,6 +177,12 @@ class MANTID_ALGORITHMS_DLL DiscusMultipleScatteringCorrection : public API::Alg
                                                          const Geometry::IObject *shapeObjectWithScatter);
   void addWorkspaceToDiscus2DData(const Geometry::IObject_const_sptr &shape, const std::string_view &matName,
                                   API::MatrixWorkspace_sptr ws);
+  void loadCollimatorInfo();
+  double getDoubleParamFromIDF(std::string paramName);
+  Kernel::V3D getV3DParamFromIDF(std::string paramName);
+  const std::shared_ptr<Geometry::CSGObject> readFromCollimatorCorridorCache(const std::size_t &histogramIndex);
+  void writeToCollimatorCorridorCache(const std::size_t &histogramIndex,
+                                      const std::shared_ptr<Geometry::CSGObject> &collimatorCorridorCsgObj);
   long long m_callsToInterceptSurface{0};
   long long m_IkCalculations{0};
   std::map<int, int> m_attemptsToGenerateInitialTrack;
@@ -177,6 +200,10 @@ class MANTID_ALGORITHMS_DLL DiscusMultipleScatteringCorrection : public API::Alg
   bool m_NormalizeSQ{};
   Geometry::BoundingBox m_activeRegion;
   std::unique_ptr<IBeamProfile> m_beamProfile;
+  Mantid::Geometry::Instrument_const_sptr m_instrument;
+  std::unique_ptr<CollimatorInfo> m_collimatorInfo;
+  std::map<std::size_t, std::shared_ptr<Geometry::CSGObject>> m_collimatorCorridorCache;
+  mutable std::shared_mutex m_mutexCorridorCache;
 };
 } // namespace Algorithms
 } // namespace Mantid