diff --git a/src/EcalBarrel_geo.cpp b/src/EcalBarrel_geo.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..4f3862df8775f9daf15ce49a8e7e245a9b524c8f
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+++ b/src/EcalBarrel_geo.cpp
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+//==========================================================================
+// AIDA Detector description implementation
+//--------------------------------------------------------------------------
+// Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
+// All rights reserved.
+//
+// For the licensing terms see $DD4hepINSTALL/LICENSE.
+// For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
+//
+// Author : M.Frank
+//
+//==========================================================================
+//
+// Specialized generic detector constructor
+//
+//==========================================================================
+#include "DD4hep/DetFactoryHelper.h"
+#include "XML/Layering.h"
+
+using namespace std;
+using namespace dd4hep;
+using namespace dd4hep::detail;
+
+static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector sens) {
+ static double tolerance = 0e0;
+ Layering layering (e);
+ xml_det_t x_det = e;
+ Material air = description.air();
+ int det_id = x_det.id();
+ string det_name = x_det.nameStr();
+ xml_comp_t x_staves = x_det.staves();
+ xml_comp_t x_dim = x_det.dimensions();
+ int nsides = x_dim.numsides();
+ double inner_r = x_dim.rmin();
+ double dphi = (2*M_PI/nsides);
+ double hphi = dphi/2;
+ double mod_z = layering.totalThickness();
+ double outer_r = inner_r + mod_z;
+ double totThick = mod_z;
+ double offset = x_det.attr<double>(_Unicode(offset));
+ DetElement sdet (det_name,det_id);
+ Volume motherVol = description.pickMotherVolume(sdet);
+ PolyhedraRegular hedra (nsides,inner_r,inner_r+totThick+tolerance*2e0,x_dim.z());
+ Volume envelope (det_name,hedra,air);
+ PlacedVolume env_phv = motherVol.placeVolume(envelope,Transform3D(Translation3D(0,0,offset)*RotationZ(M_PI/nsides)));
+
+ env_phv.addPhysVolID("system",det_id);
+ env_phv.addPhysVolID("barrel",0);
+ sdet.setPlacement(env_phv);
+
+ DetElement stave_det("stave0",det_id);
+ double dx = 0.0; //mod_z / std::sin(dphi); // dx per layer
+
+ // Compute the top and bottom face measurements.
+ double trd_x2 = (2 * std::tan(hphi) * outer_r - dx)/2 - tolerance;
+ double trd_x1 = (2 * std::tan(hphi) * inner_r + dx)/2 - tolerance;
+ double trd_y1 = x_dim.z()/2 - tolerance;
+ double trd_y2 = trd_y1;
+ double trd_z = mod_z/2 - tolerance;
+
+ // Create the trapezoid for the stave.
+ Trapezoid trd(trd_x1, // Outer side, i.e. the "short" X side.
+ trd_x2, // Inner side, i.e. the "long" X side.
+ trd_y1, // Corresponds to subdetector (or module) Z.
+ trd_y2, //
+ trd_z); // Thickness, in Y for top stave, when rotated.
+
+ Volume mod_vol("stave",trd,air);
+
+ sens.setType("calorimeter");
+ { // ===== buildBarrelStave(description, sens, module_volume) =====
+ // Parameters for computing the layer X dimension:
+ double stave_z = trd_y1;
+ double tan_hphi = std::tan(hphi);
+ double l_dim_x = trd_x1; // Starting X dimension for the layer.
+ double l_pos_z = -(layering.totalThickness() / 2);
+
+ // Loop over the sets of layer elements in the detector.
+ int l_num = 1;
+ for(xml_coll_t li(x_det,_U(layer)); li; ++li) {
+ xml_comp_t x_layer = li;
+ int repeat = x_layer.repeat();
+ // Loop over number of repeats for this layer.
+ for (int j=0; j<repeat; j++) {
+ string l_name = _toString(l_num,"layer%d");
+ double l_thickness = layering.layer(l_num-1)->thickness(); // Layer's thickness.
+
+ Position l_pos(0,0,l_pos_z+l_thickness/2); // Position of the layer.
+ Box l_box(l_dim_x-tolerance,stave_z-tolerance,l_thickness / 2-tolerance);
+ Volume l_vol(l_name,l_box,air);
+ DetElement layer(stave_det, l_name, det_id);
+
+ // Loop over the sublayers or slices for this layer.
+ int s_num = 1;
+ double s_pos_z = -(l_thickness / 2);
+ for(xml_coll_t si(x_layer,_U(slice)); si; ++si) {
+ xml_comp_t x_slice = si;
+ string s_name = _toString(s_num,"slice%d");
+ double s_thick = x_slice.thickness();
+ Box s_box(l_dim_x-tolerance,stave_z-tolerance,s_thick / 2-tolerance);
+ Volume s_vol(s_name,s_box,description.material(x_slice.materialStr()));
+ DetElement slice(layer,s_name,det_id);
+
+ if ( x_slice.isSensitive() ) {
+ s_vol.setSensitiveDetector(sens);
+ }
+ slice.setAttributes(description,s_vol,x_slice.regionStr(),x_slice.limitsStr(),x_slice.visStr());
+
+ // Slice placement.
+ PlacedVolume slice_phv = l_vol.placeVolume(s_vol,Position(0,0,s_pos_z+s_thick/2));
+ slice_phv.addPhysVolID("slice", s_num);
+ slice.setPlacement(slice_phv);
+ // Increment Z position of slice.
+ s_pos_z += s_thick;
+
+ // Increment slice number.
+ ++s_num;
+ }
+
+ // Set region, limitset, and vis of layer.
+ layer.setAttributes(description,l_vol,x_layer.regionStr(),x_layer.limitsStr(),x_layer.visStr());
+
+ PlacedVolume layer_phv = mod_vol.placeVolume(l_vol,l_pos);
+ layer_phv.addPhysVolID("layer", l_num);
+ layer.setPlacement(layer_phv);
+ // Increment to next layer Z position.
+ double xcut = l_thickness * tan_hphi;
+ l_dim_x += xcut;
+ l_pos_z += l_thickness;
+ ++l_num;
+ }
+ }
+ }
+
+ // Set stave visualization.
+ if ( x_staves ) {
+ mod_vol.setVisAttributes(description.visAttributes(x_staves.visStr()));
+ }
+ // Phi start for a stave.
+ double phi = M_PI / nsides;
+ double mod_x_off = dx / 2; // Stave X offset, derived from the dx.
+ double mod_y_off = inner_r + mod_z/2; // Stave Y offset
+
+ // Create nsides staves.
+ for (int i = 0; i < nsides; i++, phi -= dphi) { // i is module number
+ // Compute the stave position
+ double m_pos_x = mod_x_off * std::cos(phi) - mod_y_off * std::sin(phi);
+ double m_pos_y = mod_x_off * std::sin(phi) + mod_y_off * std::cos(phi);
+ Transform3D tr(RotationZYX(0,phi,M_PI*0.5),Translation3D(-m_pos_x,-m_pos_y,0));
+ PlacedVolume pv = envelope.placeVolume(mod_vol,tr);
+ pv.addPhysVolID("system",det_id);
+ pv.addPhysVolID("barrel",0);
+ pv.addPhysVolID("module",i+1);
+ DetElement sd = i==0 ? stave_det : stave_det.clone(_toString(i,"stave%d"));
+ sd.setPlacement(pv);
+ sdet.add(sd);
+ }
+
+ // Set envelope volume attributes.
+ envelope.setAttributes(description,x_det.regionStr(),x_det.limitsStr(),x_det.visStr());
+ return sdet;
+}
+
+DECLARE_DETELEMENT(refdet_EcalBarrel,create_detector)