From 2ae1dd82287b9440058f4a11a546c08c979fb612 Mon Sep 17 00:00:00 2001
From: EricMEsch <eric.esch@student.uni-tuebingen.de>
Date: Thu, 5 Dec 2024 18:33:04 +0100
Subject: [PATCH] add distance to nearest surface field to
 GermaniumOutputScheme

---
 include/RMGGermaniumDetector.hh |  1 +
 src/RMGGermaniumDetector.cc     | 33 +++++++++++++++++++++++++++++++--
 src/RMGGermaniumOutputScheme.cc |  3 +++
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/include/RMGGermaniumDetector.hh b/include/RMGGermaniumDetector.hh
index a92be404..689c7cb9 100644
--- a/include/RMGGermaniumDetector.hh
+++ b/include/RMGGermaniumDetector.hh
@@ -48,6 +48,7 @@ class RMGGermaniumDetectorHit : public G4VHit {
     int detector_uid = -1;
     int particle_type = -1;
     float energy_deposition = -1;
+    float distance_to_surface = -1;
     G4ThreeVector global_position;
     double global_time = -1;
 };
diff --git a/src/RMGGermaniumDetector.cc b/src/RMGGermaniumDetector.cc
index f4084fb4..6dd2f8e1 100644
--- a/src/RMGGermaniumDetector.cc
+++ b/src/RMGGermaniumDetector.cc
@@ -19,6 +19,7 @@
 #include <stdexcept>
 #include <string>
 
+#include "G4AffineTransform.hh"
 #include "G4Circle.hh"
 #include "G4HCofThisEvent.hh"
 #include "G4OpticalPhoton.hh"
@@ -89,10 +90,14 @@ bool RMGGermaniumDetector::ProcessHits(G4Step* step, G4TouchableHistory* /*histo
 
   // we're going to use info from the pre-step point
   const auto prestep = step->GetPreStepPoint();
+  const auto position = prestep->GetPosition();
 
   // locate us
-  const auto pv_name = prestep->GetTouchableHandle()->GetVolume()->GetName();
+  const auto pv = prestep->GetTouchableHandle()->GetVolume();
+  const auto pv_name = pv->GetName();
   const auto pv_copynr = prestep->GetTouchableHandle()->GetCopyNumber();
+  const auto lv = pv->GetLogicalVolume();
+  const auto sv = lv->GetSolid();
 
   // check if physical volume is registered as germanium detector
   const auto det_cons = RMGManager::Instance()->GetDetectorConstruction();
@@ -119,9 +124,33 @@ bool RMGGermaniumDetector::ProcessHits(G4Step* step, G4TouchableHistory* /*histo
   hit->detector_uid = det_uid;
   hit->particle_type = step->GetTrack()->GetDefinition()->GetPDGEncoding();
   hit->energy_deposition = step->GetTotalEnergyDeposit();
-  hit->global_position = prestep->GetPosition();
+  hit->global_position = position;
   hit->global_time = prestep->GetGlobalTime();
 
+  // Get distance to surface.
+  // Check distance to surfaces of Mother volume
+  //
+
+  // First transform coordinates into local system
+  G4AffineTransform Tf(pv->GetRotation(), pv->GetTranslation());
+  Tf.Invert();
+  float dist = sv->DistanceToOut(Tf.TransformPoint(position));
+
+  // Also check distance to daughters if there are any. Analogue to G4NormalNavigation.cc
+  int localNoDaughters = lv->GetNoDaughters();
+  // sampleNo has to be signed, so auto typing does not work
+  for (int sampleNo = localNoDaughters - 1; sampleNo >= 0; sampleNo--) {
+    const auto samplePhysical = lv->GetDaughter(sampleNo);
+    G4AffineTransform sampleTf(samplePhysical->GetRotation(), samplePhysical->GetTranslation());
+    sampleTf.Invert();
+    const G4ThreeVector samplePoint = sampleTf.TransformPoint(position);
+    const G4VSolid* sampleSolid = samplePhysical->GetLogicalVolume()->GetSolid();
+    const G4double sampleDist = sampleSolid->DistanceToIn(samplePoint);
+    if (sampleDist < dist) { dist = sampleDist; }
+  }
+
+  hit->distance_to_surface = dist;
+
   // register the hit in the hit collection for the event
   fHitsCollection->insert(hit);
 
diff --git a/src/RMGGermaniumOutputScheme.cc b/src/RMGGermaniumOutputScheme.cc
index 4ea13601..a7fce6bb 100644
--- a/src/RMGGermaniumOutputScheme.cc
+++ b/src/RMGGermaniumOutputScheme.cc
@@ -69,6 +69,7 @@ void RMGGermaniumOutputScheme::AssignOutputNames(G4AnalysisManager* ana_man) {
     CreateNtupleFOrDColumn(ana_man, id, "xloc_in_m", fStoreSinglePrecisionPosition);
     CreateNtupleFOrDColumn(ana_man, id, "yloc_in_m", fStoreSinglePrecisionPosition);
     CreateNtupleFOrDColumn(ana_man, id, "zloc_in_m", fStoreSinglePrecisionPosition);
+    CreateNtupleFOrDColumn(ana_man, id, "SurfaceDist_in_m", fStoreSinglePrecisionPosition);
 
     ana_man->FinishNtuple(id);
   }
@@ -159,6 +160,8 @@ void RMGGermaniumOutputScheme::StoreEvent(const G4Event* event) {
           fStoreSinglePrecisionPosition);
       FillNtupleFOrDColumn(ana_man, ntupleid, col_id++, hit->global_position.getZ() / u::m,
           fStoreSinglePrecisionPosition);
+      FillNtupleFOrDColumn(ana_man, ntupleid, col_id++, hit->distance_to_surface / u::m,
+          fStoreSinglePrecisionPosition);
 
       // NOTE: must be called here for hit-oriented output
       ana_man->AddNtupleRow(ntupleid);