Carry the CPV geometry in double

This removes the gaps between the CPV frame and its active planes and converts the CPV geometry
from float to double.

- The frame and the active planes it touches were placed from two different float sums of the
  same plane, 38 nm apart in twelve pairs, and CPVF and CPVAr were 0.11 nm apart.
- The GeometryParams members and getters, the shape half-lengths and the placement coordinates
  are double; the class version is bumped.
- The twelve near-coincident face pairs in the CPV mother are gone.
- In a PIPE plus CPV geometry, CPV hits under VecGeom navigation go from 0 to 6876, against 7392
  with TGeo.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: sawenzel

Detectors/CPV/simulation/include/CPVSimulation/GeometryParams.h

@@ -40,7 +40,7 @@ class GeometryParams final : public TNamed
     return sGeomParam;
   }
 
-  void GetModuleAngle(int module, float angle[3][2]) const
+  void GetModuleAngle(int module, double angle[3][2]) const
   {
     for (int i = 0; i < 3; i++) {
       for (int ian = 0; ian < 2; ian++) {
@@ -49,9 +49,9 @@ class GeometryParams final : public TNamed
     }
   }
 
-  float GetCPVAngle(Int_t index) const { return mCPVAngle[index - 1]; }
+  double GetCPVAngle(Int_t index) const { return mCPVAngle[index - 1]; }
 
-  void GetModuleCenter(int module, float* pos) const
+  void GetModuleCenter(int module, double* pos) const
   {
     for (int i = 0; i < 3; i++) {
       pos[i] = mModuleCenter[module][i];
@@ -61,18 +61,18 @@ class GeometryParams final : public TNamed
   int GetNModules() const { return mNModules; }
   int GetNumberOfCPVPadsPhi() const { return mNumberOfCPVPadsPhi; }
   int GetNumberOfCPVPadsZ() const { return mNumberOfCPVPadsZ; }
-  float GetCPVPadSizePhi() const { return mCPVPadSizePhi; }
-  float GetCPVPadSizeZ() const { return mCPVPadSizeZ; }
-  float GetCPVBoxSize(int index) const { return mCPVBoxSize[index]; }
-  float GetCPVActiveSize(int index) const { return mCPVActiveSize[index]; }
+  double GetCPVPadSizePhi() const { return mCPVPadSizePhi; }
+  double GetCPVPadSizeZ() const { return mCPVPadSizeZ; }
+  double GetCPVBoxSize(int index) const { return mCPVBoxSize[index]; }
+  double GetCPVActiveSize(int index) const { return mCPVActiveSize[index]; }
   int GetNumberOfCPVChipsPhi() const { return mNumberOfCPVChipsPhi; }
   int GetNumberOfCPVChipsZ() const { return mNumberOfCPVChipsZ; }
-  float GetGassiplexChipSize(int index) const { return mGassiplexChipSize[index]; }
-  float GetCPVGasThickness() const { return mCPVGasThickness; }
-  float GetCPVTextoliteThickness() const { return mCPVTextoliteThickness; }
-  float GetCPVCuNiFoilThickness() const { return mCPVCuNiFoilThickness; }
-  float GetFTPosition(int index) const { return mFTPosition[index]; }
-  float GetCPVFrameSize(int index) const { return mCPVFrameSize[index]; }
+  double GetGassiplexChipSize(int index) const { return mGassiplexChipSize[index]; }
+  double GetCPVGasThickness() const { return mCPVGasThickness; }
+  double GetCPVTextoliteThickness() const { return mCPVTextoliteThickness; }
+  double GetCPVCuNiFoilThickness() const { return mCPVCuNiFoilThickness; }
+  double GetFTPosition(int index) const { return mFTPosition[index]; }
+  double GetCPVFrameSize(int index) const { return mCPVFrameSize[index]; }
 
  private:
   ///
@@ -86,23 +86,23 @@ class GeometryParams final : public TNamed
   int mNModules;                // Number of CPV modules
   int mNumberOfCPVPadsPhi;      // Number of CPV pads in phi
   int mNumberOfCPVPadsZ;        // Number of CPV pads in z
-  float mCPVPadSizePhi;         // CPV pad size in phi
-  float mCPVPadSizeZ;           // CPV pad size in z
-  float mCPVBoxSize[3];         // Outer size of CPV box
-  float mCPVActiveSize[2];      // Active size of CPV box (x,z)
+  double mCPVPadSizePhi;        // CPV pad size in phi
+  double mCPVPadSizeZ;          // CPV pad size in z
+  double mCPVBoxSize[3];        // Outer size of CPV box
+  double mCPVActiveSize[2];     // Active size of CPV box (x,z)
   int mNumberOfCPVChipsPhi;     // Number of CPV Gassiplex chips in phi
   int mNumberOfCPVChipsZ;       // Number of CPV Gassiplex chips in z
-  float mGassiplexChipSize[3];  // Size of a Gassiplex chip (0 - in z, 1 - in phi, 2 - thickness (in ALICE radius))
-  float mCPVGasThickness;       // Thickness of CPV gas volume
-  float mCPVTextoliteThickness; // Thickness of CPV textolite PCB (without moil)
-  float mCPVCuNiFoilThickness;  // Thickness of CPV Copper-Nickel moil of PCB
-  float mFTPosition[4];         // Positions of the 4 PCB vs the CPV box center
-  float mCPVFrameSize[3];       // CPV frame size (0 - in phi, 1 - in z, 2 - thickness (along ALICE radius))
-  float mIPtoCPVSurface;        // Distance from IP to CPV front cover
-  float mModuleAngle[5][3][2];  // Orientation angles of CPV modules
-  float mCPVAngle[5];           // Direction to the center of CPV modules in phi
-  float mModuleCenter[5][3];    // Coordunates of modules centra in ALICE system
-  ClassDefOverride(GeometryParams, 1);
+  double mGassiplexChipSize[3]; // Size of a Gassiplex chip (0 - in z, 1 - in phi, 2 - thickness (in ALICE radius))
+  double mCPVGasThickness;      // Thickness of CPV gas volume
+  double mCPVTextoliteThickness; // Thickness of CPV textolite PCB (without moil)
+  double mCPVCuNiFoilThickness;  // Thickness of CPV Copper-Nickel moil of PCB
+  double mFTPosition[4];         // Positions of the 4 PCB vs the CPV box center
+  double mCPVFrameSize[3];       // CPV frame size (0 - in phi, 1 - in z, 2 - thickness (along ALICE radius))
+  double mIPtoCPVSurface;        // Distance from IP to CPV front cover
+  double mModuleAngle[5][3][2];  // Orientation angles of CPV modules
+  double mCPVAngle[5];           // Direction to the center of CPV modules in phi
+  double mModuleCenter[5][3];    // Coordunates of modules centra in ALICE system
+  ClassDefOverride(GeometryParams, 2);
 };
 } // namespace cpv
 } // namespace o2

Detectors/CPV/simulation/src/Detector.cxx

@@ -358,7 +358,7 @@ void Detector::ConstructGeometry()
   CreateMaterials();
 
   // Create a CPV modules-containers which will be filled with the stuff later.
-  float par[3], x, y, z;
+  double par[3], x, y, z;
 
   // The box containing all CPV filled with air
   par[0] = geomParams->GetCPVBoxSize(0) / 2.0;
@@ -372,11 +372,11 @@ void Detector::ConstructGeometry()
     if (!mActiveModule[iModule]) {
       continue;
     }
-    float angle[3][2] = {0};
+    double angle[3][2] = {0};
     geomParams->GetModuleAngle(iModule, angle);
     Matrix(idrotm[iModule], angle[0][0], angle[0][1], angle[1][0], angle[1][1], angle[2][0], angle[2][1]);
 
-    float pos[3] = {0};
+    double pos[3] = {0};
     geomParams->GetModuleCenter(iModule, pos);
 
     fMC->Gspos("CPV", iModule, "barrel", pos[0], pos[1] + 30., pos[2], idrotm[iModule], "ONLY");
@@ -396,8 +396,8 @@ void Detector::ConstructGeometry()
   fMC->Gspos("CPVC", 1, "CPVG", 0, y, 0, 0, "ONLY");
 
   // Position of the chip inside CPV
-  float xStep = geomParams->GetCPVActiveSize(0) / (geomParams->GetNumberOfCPVChipsPhi() + 1);
-  float zStep = geomParams->GetCPVActiveSize(1) / (geomParams->GetNumberOfCPVChipsZ() + 1);
+  double xStep = geomParams->GetCPVActiveSize(0) / (geomParams->GetNumberOfCPVChipsPhi() + 1);
+  double zStep = geomParams->GetCPVActiveSize(1) / (geomParams->GetNumberOfCPVChipsZ() + 1);
   int copy = 0;
   y = geomParams->GetCPVFrameSize(1) / 2 - geomParams->GetFTPosition(0) +
       geomParams->GetCPVTextoliteThickness() / 2 + geomParams->GetGassiplexChipSize(1) / 2 + 0.1;
@@ -451,10 +451,20 @@ void Detector::ConstructGeometry()
   par[2] = geomParams->GetCPVFrameSize(2) / 2;
   fMC->Gsvolu("CPVF2", "BOX ", getMediumID(ID_AL), par, 3);
 
+  // The frame's inner faces are the edges of the active plane. Deriving them from the box and
+  // frame sizes instead of from the active size left CPVF2 38 nm away from CPVF and CPVAr:
+  // algebraically the same plane, different float sums. TGeo relocates from a point pushed far
+  // past a boundary and never notices; VecGeom answers DistanceToOut = -1 and gives the volume
+  // back to its mother. Place the frame against the halves the active volumes were actually
+  // given, so the faces land on the same double.
+  const double activeHalfX = geomParams->GetCPVActiveSize(0) / 2;
+  const double activeHalfZ = geomParams->GetCPVActiveSize(1) / 2;
+  const double frameHalfX = geomParams->GetCPVFrameSize(0) / 2;
+  const double frameHalfZ = geomParams->GetCPVFrameSize(2) / 2;
   for (int j = 0; j <= 1; j++) {
-    x = TMath::Sign(1, 2 * j - 1) * (geomParams->GetCPVBoxSize(0) - geomParams->GetCPVFrameSize(0)) / 2;
+    x = TMath::Sign(1, 2 * j - 1) * (activeHalfX + frameHalfX);
     fMC->Gspos("CPVF1", j + 1, "CPV", x, 0, 0, 0, "ONLY");
-    z = TMath::Sign(1, 2 * j - 1) * (geomParams->GetCPVBoxSize(2) - geomParams->GetCPVFrameSize(2)) / 2;
+    z = TMath::Sign(1, 2 * j - 1) * (activeHalfZ + frameHalfZ);
     fMC->Gspos("CPVF2", j + 1, "CPV", 0, 0, z, 0, "ONLY");
   }
 
@@ -590,7 +600,7 @@ void Detector::addAlignableVolumes() const
     LOG(debug) << "Got TGeoPNEntry " << alignableEntry;
 
     if (alignableEntry) {
-      Float_t angle = geom->GetCPVAngle(iModule);
+      double angle = geom->GetCPVAngle(iModule);
       TGeoHMatrix* globMatrix = alignableEntry->GetGlobalOrig();
 
       TGeoHMatrix* matTtoL = new TGeoHMatrix;