add skeleton for trapezoid segmentation

src/TrapezoidSegmentation.cpp

+// Trapezoid Segmentation for GlueX type barrel calorimeter
+// Author: M. Zurek, C. Peng (ANL)
+// Date: 06/25/2021
+
+#include "DD4hep/Factories.h"
+#include "DD4hep/detail/SegmentationsInterna.h"
+#include "DDSegmentation/Segmentation.h"
+
+
+using namespace dd4hep::DDSegmentation;
+
+namespace athena::seg {
+  class TrapezoidGrid: public Segmentation {
+    public:
+      // Default constructor used by derived classes passing the encoding string
+      TrapezoidGrid(const std::string& cellEncoding = "")
+        : Segmentation(cellEncoding)
+      {
+        // define type and description
+        _type = "TrapezoidGrid";
+        _description = "Trapezoid segmentation in the local YZ-plane";
+        registerParameters();
+      }
+
+      // Default constructor used by derived classes passing an existing decoder
+      TrapezoidGrid(const BitFieldCoder* decoder)
+        : Segmentation(decoder)
+      {
+        // define type and description
+        _type = "TrapezoidGrid";
+        _description = "Trapezoid segmentation in the local YZ-plane";
+        registerParameters();
+      }
+
+      // Destructor
+      virtual ~TrapezoidGrid() {}
+
+      void registerParameters()
+      {
+        // @TODO: register all necessary parameters
+        // mandatory
+        registerParameter("grid_size_y", "Cell size in Y", _gridSizeY, 1., SegmentationParameter::LengthUnit);
+        // optional
+        registerIdentifier("identifier_y", "Cell ID identifier for Y", _yId, "y");
+      }
+
+      // override
+      virtual Vector3D position(const CellID& cellID) const
+      {
+        // @TODO
+        /* PolarGridRPhi
+        Vector3D cellPosition;
+        double R =   binToPosition(_decoder->get(cID,_rId),   _gridSizeR,   _offsetR);
+        double phi = binToPosition(_decoder->get(cID,_phiId), _gridSizePhi, _offsetPhi);
+
+        cellPosition.X = R * cos(phi);
+        cellPosition.Y = R * sin(phi);
+
+        return cellPosition;
+        */
+        return Vector3D();
+      }
+
+      // override
+      virtual CellID cellID(const Vector3D& localPosition, const Vector3D& globalPosition, const VolumeID& volumeID) const
+      {
+        // @TODO
+        /* PolarGridRPhi
+        double phi = atan2(localPosition.Y,localPosition.X);
+        double R = sqrt( localPosition.X * localPosition.X + localPosition.Y * localPosition.Y );
+        CellID cID = vID ;
+        _decoder->set(cID,_rId  , positionToBin(R, _gridSizeR, _offsetR));
+        _decoder->set(cID,_phiId, positionToBin(phi, _gridSizePhi, _offsetPhi));
+        */
+        return volumeID;
+      }
+
+      // override
+      virtual std::vector<double> cellDimensions(const CellID& cellID) const
+      {
+        // @TODO
+        /* PolarGridRPhi
+        const double rPhiSize = binToPosition(_decoder->get(cID,_rId), _gridSizeR, _offsetR)*_gridSizePhi;
+        return {_gridSizeR, rPhiSize};
+        */
+        return std::vector<double>{0., 0., 0.};
+      }
+
+
+      // public methods to get member value
+      double gridSizeY() const { return _gridSizeY; }
+      const std::string& fieldNameY() const { return _yId; }
+      // public methods to set member value
+      void setGridSizeY(double cellSize) { _gridSizeY = cellSize; }
+      void setFieldNameY(const std::string& fieldName) { _yId = fieldName; }
+
+    protected:
+      // @TODO: add parameters accordingly
+      double _gridSizeY;
+      std::string _yId;
+
+
+  }; // class TrapezoidGrid
+} // namespace athena::seg
+
+DECLARE_SEGMENTATION(TrapezoidGrid, new dd4hep::SegmentationWrapper<athena::seg::TrapezoidGrid>)
+