From 9dade08cf0e56fd9e1ab3368bb2aadf5aea3a5d2 Mon Sep 17 00:00:00 2001
From: Matteo Vicenzi <matteo.vicenzi7@gmail.com>
Date: Thu, 11 Sep 2025 10:29:39 -0400
Subject: [PATCH] delete and recreate GDML file each time

---
 include/DetectorConstruction.hh | 3 ++-
 src/DetectorConstruction.cc     | 9 ++++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/include/DetectorConstruction.hh b/include/DetectorConstruction.hh
index 2a4a2ff..5f8190d 100644
--- a/include/DetectorConstruction.hh
+++ b/include/DetectorConstruction.hh
@@ -8,6 +8,7 @@
 #include <G4AssemblyVolume.hh>
 #include "fields/BabyMINDMagneticField.hh"
 #include <vector>
+#include <string>
 
 class G4LogicalVolume;
 class DetectorConstructionMessenger;
@@ -48,7 +49,7 @@ class DetectorConstruction : public G4VUserDetectorConstruction {
     DetectorConstructionMessenger* messenger;
 
     G4bool m_saveGdml;
-    G4String m_fileGdml;
+    std::string m_fileGdml;
     G4bool fCheckOverlap;
     G4bool m_addFLArE;
     G4bool m_useBabyMIND;
diff --git a/src/DetectorConstruction.cc b/src/DetectorConstruction.cc
index 6d11af7..5cb6427 100644
--- a/src/DetectorConstruction.cc
+++ b/src/DetectorConstruction.cc
@@ -39,7 +39,8 @@
 #include <G4GDMLParser.hh>
 #include <G4SubtractionSolid.hh>
 
-using namespace std;
+#include <filesystem>
+#include <string>
 
 G4ThreadLocal G4UniformMagField* DetectorConstruction::magField = 0;
 G4ThreadLocal G4FieldManager* DetectorConstruction::fieldMgr = 0;
@@ -272,6 +273,12 @@ G4VPhysicalVolume* DetectorConstruction::Construct()
   if (m_saveGdml) {
     G4GDMLParser fParser;
     G4cout << "Exporting geometry to " << m_fileGdml << G4endl;
+
+    if(std::filesystem::exists(m_fileGdml)){
+      G4cout << "  File already exists. Deleting first..." << G4endl;
+      std::filesystem::remove(m_fileGdml);
+    }
+
     fParser.Write(m_fileGdml, worldPV, false);
   }