refactor(Calorimeter): modernise code with C++23 features and clearer naming

CMakeLists.txt

@@ -10,8 +10,8 @@ project(
     LANGUAGES CXX
 )
 
-# Set C++20 standard
-set(CMAKE_CXX_STANDARD 20)
+# C++23: required by Phlex
+set(CMAKE_CXX_STANDARD 23)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 

subsystems/Calorimeter/include/Calorimeter/CaloBarLayer.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include <string>
+#include <string_view>
 
 class GeoVPhysVol;
 class GeoLogVol;
@@ -20,11 +21,12 @@ enum class BarAxis { AlongX, AlongY };
  * centre-to-centre, centred on the mother origin in the transverse plane,
  * and all placed at @p zCenter_mm along Z (local coordinates).
  */
-class CaloBarLayer {
-   public:
-    static void place(GeoVPhysVol* mother, GeoLogVol* barLog, double pitch_mm, int nBars,
-                      double zCenter_mm, const char* tagPrefix, int layerIndex, BarAxis axis,
-                      const std::string& nameSuffix = "");
-};
+namespace CaloBar {
+
+void placeLayer(GeoVPhysVol* mother, GeoLogVol* barLog, double pitch_mm, int nBars,
+                double zCenter_mm, std::string_view tagPrefix, int layerIndex, BarAxis axis,
+                const std::string& nameSuffix = "");
+
+}  // namespace CaloBar
 
 }  // namespace SHiPGeometry

subsystems/Calorimeter/include/Calorimeter/CaloFibreHPLayer.h

@@ -17,12 +17,13 @@ namespace SHiPGeometry {
  * cylindrical fibres (cladding + core). Fibres run along Y when
  * @p fibresAlongY is true, along X otherwise.
  */
-class CaloFibreHPLayer {
-   public:
-    static void build(GeoVPhysVol* mother, GeoMaterial* aluminiumMat, GeoMaterial* fibreMat,
-                      const std::string& layerTag, double zCenter_mm, int layerIndex,
-                      double casingXY_mm, double casingZ_mm, double fiberDiam_mm,
-                      double fiberCoreDiam_mm, bool fibresAlongY, const std::string& nameSuffix);
-};
+namespace CaloFibreHP {
+
+void buildLayer(GeoVPhysVol* mother, GeoMaterial* aluminiumMat, GeoMaterial* fibreMat,
+                const std::string& layerTag, double zCenter_mm, int layerIndex, double casingXY_mm,
+                double casingZ_mm, double fiberDiam_mm, double fiberCoreDiam_mm, bool fibresAlongY,
+                const std::string& nameSuffix);
+
+}  // namespace CaloFibreHP
 
 }  // namespace SHiPGeometry

subsystems/Calorimeter/include/Calorimeter/CalorimeterConfig.h

@@ -8,6 +8,18 @@
 
 namespace SHiPGeometry {
 
+/// Layer type codes used in the ECAL/HCAL layer sequences.
+enum class LayerCode : int {
+    WidePVT_H = 1,   ///< Wide PVT bar layer, bars along X (H orientation)
+    WidePVT_V = 2,   ///< Wide PVT bar layer, bars along Y (V orientation)
+    ThinPS_H = 3,    ///< Thin PS bar layer, bars along X (H orientation)
+    ThinPS_V = 4,    ///< Thin PS bar layer, bars along Y (V orientation)
+    FibreHPL_Y = 5,  ///< HPL fibre layer, fibres along Y
+    FibreHPL_X = 6,  ///< HPL fibre layer, fibres along X
+    Absorber = 7,    ///< Absorber plate (Lead in ECAL, Iron in HCAL)
+    AirGap = 8,      ///< Air gap (no volume, just advances z cursor)
+};
+
 /**
  * @brief Configuration for the SHiP calorimeter geometry.
  *

subsystems/Calorimeter/include/Calorimeter/CalorimeterFactory.h

@@ -49,7 +49,7 @@ class CalorimeterFactory {
     std::string m_configPath;
 
     /** Place one NX×NY tiled stack of layers inside @p container. */
-    void buildStack(GeoPhysVol* container, const CalorimeterConfig& cfg, int mx, int my,
+    void buildStack(GeoPhysVol* container, const CalorimeterConfig& cfg, int moduleX, int moduleY,
                     double offsetX, double offsetY) const;
 
     // ── Fixed container dimensions (mm) ─────────────────────────────────

subsystems/Calorimeter/src/CaloBarLayer.cpp

@@ -9,29 +9,29 @@
 #include <GeoModelKernel/GeoTransform.h>
 #include <GeoModelKernel/Units.h>
 
+#include <format>
 #include <string>
 
 namespace SHiPGeometry {
 
 using namespace GeoModelKernelUnits;
 
-void CaloBarLayer::place(GeoVPhysVol* mother, GeoLogVol* barLog, double pitch_mm, int nBars,
-                         double zCenter_mm, const char* tagPrefix, int layerIndex, BarAxis axis,
-                         const std::string& nameSuffix) {
+void CaloBar::placeLayer(GeoVPhysVol* mother, GeoLogVol* barLog, double pitch_mm, int nBars,
+                         double zCenter_mm, std::string_view tagPrefix, int layerIndex,
+                         BarAxis axis, const std::string& nameSuffix) {
     const double pitch = pitch_mm * mm;
-    const double s0 = -0.5 * (nBars - 1) * pitch;
+    const double firstBarCenter = -0.5 * (nBars - 1) * pitch;
 
     for (int i = 0; i < nBars; ++i) {
-        const double s = s0 + i * pitch;
+        const double barCenter = firstBarCenter + i * pitch;
 
         double x = 0.0, y = 0.0;
         if (axis == BarAxis::AlongX)
-            x = s;
+            x = barCenter;
         else
-            y = s;
+            y = barCenter;
 
-        const std::string name = std::string(tagPrefix) + "_L" + std::to_string(layerIndex) + "_B" +
-                                 std::to_string(i) + nameSuffix;
+        const auto name = std::format("{}_L{}_B{}{}", tagPrefix, layerIndex, i, nameSuffix);
 
         auto* barPhys = new GeoPhysVol(barLog);
         mother->add(new GeoNameTag(name.c_str()));

subsystems/Calorimeter/src/CaloFibreHPLayer.cpp

@@ -13,14 +13,15 @@
 
 #include <algorithm>
 #include <cmath>
+#include <format>
 #include <stdexcept>
 #include <string>
 
 namespace SHiPGeometry {
 
 using namespace GeoModelKernelUnits;
 
-void CaloFibreHPLayer::build(GeoVPhysVol* mother, GeoMaterial* aluminiumMat, GeoMaterial* fibreMat,
+void CaloFibreHP::buildLayer(GeoVPhysVol* mother, GeoMaterial* aluminiumMat, GeoMaterial* fibreMat,
                              const std::string& layerTag, double zCenter_mm, int layerIndex,
                              double casingXY_mm, double casingZ_mm, double fiberDiam_mm,
                              double fiberCoreDiam_mm, bool fibresAlongY,
@@ -43,7 +44,7 @@ void CaloFibreHPLayer::build(GeoVPhysVol* mother, GeoMaterial* aluminiumMat, Geo
 
     if (rCore <= 0.0 || rCore > rOuter)
         throw std::runtime_error(
-            "CaloFibreHPLayer: invalid core diameter "
+            "CaloFibreHP::buildLayer: invalid core diameter "
             "(must be >0 and <= outer diameter)");
 
     // GeoTube axis is Z; rotate so fibres run along Y or X
@@ -70,25 +71,24 @@ void CaloFibreHPLayer::build(GeoVPhysVol* mother, GeoMaterial* aluminiumMat, Geo
 
     const std::string orient = fibresAlongY ? "V_L" : "H_L";
 
-    for (int s = 0; s < 3; ++s) {
+    for (int sublayer = 0; sublayer < 3; ++sublayer) {
         for (int i = 0; i < nFib; ++i) {
-            const double pack = x0 + i * pitch + dx[s];
-            const double zl = zLocal[s];
+            const double fibrePosition = x0 + i * pitch + dx[sublayer];
+            const double sublayerZ = zLocal[sublayer];
 
-            const std::string baseName = layerTag + "_HPL_" + orient + std::to_string(layerIndex) +
-                                         "_S" + std::to_string(s) + "_F" + std::to_string(i) +
-                                         nameSuffix;
+            const auto baseName = std::format("{}_HPL_{}{}_S{}_F{}{}", layerTag, orient, layerIndex,
+                                              sublayer, i, nameSuffix);
 
             // cladding physical volume; core is a child of it
             auto* cladPhys = new GeoPhysVol(cladLog);
-            cladPhys->add(new GeoNameTag((baseName + "_Core").c_str()));
+            cladPhys->add(new GeoNameTag(std::format("{}_Core", baseName).c_str()));
             cladPhys->add(new GeoPhysVol(coreLog));
 
-            const double xPos = fibresAlongY ? pack : 0.0;
-            const double yPos = fibresAlongY ? 0.0 : pack;
+            const double xPos = fibresAlongY ? fibrePosition : 0.0;
+            const double yPos = fibresAlongY ? 0.0 : fibrePosition;
 
-            casingPhys->add(new GeoNameTag((baseName + "_Clad").c_str()));
-            casingPhys->add(new GeoTransform(GeoTrf::Translate3D(xPos, yPos, zl) * rotAxis));
+            casingPhys->add(new GeoNameTag(std::format("{}_Clad", baseName).c_str()));
+            casingPhys->add(new GeoTransform(GeoTrf::Translate3D(xPos, yPos, sublayerZ) * rotAxis));
             casingPhys->add(cladPhys);
         }
     }