From 12657167f1f426d33e6f192c99212b6af675ac26 Mon Sep 17 00:00:00 2001
From: AndreaRigoni <andrea.rigoni@igi.cnr.it>
Date: Thu, 19 Mar 2026 10:21:01 +0000
Subject: [PATCH] add detector chamber projection plane representation in vtk

---
 .../testing/vtkDetectorChamberTest.cpp        |  4 +-
 src/Vtk/HEP/Detectors/vtkDetectorChamber.cxx  | 69 +++++++++++++++++++
 src/Vtk/HEP/Detectors/vtkDetectorChamber.h    |  8 +++
 3 files changed, 79 insertions(+), 2 deletions(-)

diff --git a/src/Vtk/HEP/Detectors/testing/vtkDetectorChamberTest.cpp b/src/Vtk/HEP/Detectors/testing/vtkDetectorChamberTest.cpp
index 4f1092b..f3c3563 100644
--- a/src/Vtk/HEP/Detectors/testing/vtkDetectorChamberTest.cpp
+++ b/src/Vtk/HEP/Detectors/testing/vtkDetectorChamberTest.cpp
@@ -43,8 +43,8 @@ BOOST_AUTO_TEST_CASE(vtkDetectorChamberTest) {
 
   // d2.SetSize(Vector3f(1, 1, 1));
   // d2.SetPosition(Vector3f(0, 0, 0));
-  d2.Scale(Vector3f(1000, 2000, 200));
-  d2.Translate(Vector3f(0, 0, 10));
+  d2.Scale(Vector3f(1_m, 2_m, 20_cm));
+  d2.Translate(Vector3f(0, 0, 10_m));
 
 
   Vtk::vtkDetectorChamber v_d1(&d1);
diff --git a/src/Vtk/HEP/Detectors/vtkDetectorChamber.cxx b/src/Vtk/HEP/Detectors/vtkDetectorChamber.cxx
index 52cadcb..af033a6 100644
--- a/src/Vtk/HEP/Detectors/vtkDetectorChamber.cxx
+++ b/src/Vtk/HEP/Detectors/vtkDetectorChamber.cxx
@@ -41,20 +41,89 @@
 #include "Vtk/HEP/Detectors/vtkDetectorChamber.h"
 #include <vtkBoxWidget.h>
 #include <vtkTransformPolyDataFilter.h>
+#include <vtkPlaneSource.h>
+#include <vtkProperty.h>
+#include <vtkNew.h>
 
 namespace uLib {
 namespace Vtk {
 
 vtkDetectorChamber::vtkDetectorChamber(DetectorChamber *content)
     : vtkContainerBox(content) {
+  m_PlaneSource = vtkPlaneSource::New();
+  
+  vtkNew<vtkPolyDataMapper> mapper;
+  mapper->SetInputConnection(m_PlaneSource->GetOutputPort());
+  
+  m_PlaneActor = vtkActor::New();
+  m_PlaneActor->SetMapper(mapper);
+  m_PlaneActor->GetProperty()->SetColor(0.2, 0.8, 0.2); // Light green
+  m_PlaneActor->GetProperty()->SetOpacity(0.3);
+  m_PlaneActor->GetProperty()->SetAmbient(1.0);
+  m_PlaneActor->GetProperty()->SetDiffuse(0.0);
+  
+  this->SetProp(m_PlaneActor);
+  
+  this->contentUpdate();
 }
 
 vtkDetectorChamber::~vtkDetectorChamber() {
+  m_PlaneSource->Delete();
+  m_PlaneActor->Delete();
 }
 
 DetectorChamber *vtkDetectorChamber::GetContent() {
   return static_cast<DetectorChamber *>(m_Content);
 }
 
+void vtkDetectorChamber::contentUpdate() {
+  this->BaseClass::contentUpdate();
+
+  if (!m_Content) return;
+  DetectorChamber *c = this->GetContent();
+  Vector3f size = c->GetSize();
+  HLine3f plane = c->GetProjectionPlane();
+
+  // Normalized local space of the chamber
+  float Lx = plane.origin.x() / size.x();
+  float Ly = plane.origin.y() / size.y();
+  float Lz = plane.origin.z() / size.z();
+  
+  float Dx = plane.direction.x() * size.x();
+  float Dy = plane.direction.y() * size.y();
+  float Dz = plane.direction.z() * size.z();
+
+  Vector3f normal(Dx, Dy, Dz);
+  normal.normalize();
+
+  // Find spans
+  Vector3f v1;
+  if (std::abs(normal.z()) < 0.9) v1 = Vector3f(0,0,1);
+  else v1 = Vector3f(1,0,0);
+  
+  Vector3f p1 = normal.cross(v1).normalized();
+  Vector3f p2 = normal.cross(p1).normalized();
+  
+  // Center the visual representation on the box extents (unit box [0,1]^3)
+  // instead of the plane origin (which might be a corner).
+  Vector3f boxCenter(0.5f, 0.5f, 0.5f);
+  Vector3f planePt(Lx, Ly, Lz);
+  Vector3f visualCenter = boxCenter - (boxCenter - planePt).dot(normal) * normal;
+  
+  float scale = 1.5; // Slightly larger than the diagonal of a face (1.41)
+  
+  m_PlaneSource->SetOrigin(visualCenter.x() - 0.5f*scale*p1.x() - 0.5f*scale*p2.x(),
+                           visualCenter.y() - 0.5f*scale*p1.y() - 0.5f*scale*p2.y(),
+                           visualCenter.z() - 0.5f*scale*p1.z() - 0.5f*scale*p2.z());
+                           
+  m_PlaneSource->SetPoint1(visualCenter.x() + 0.5f*scale*p1.x() - 0.5f*scale*p2.x(),
+                           visualCenter.y() + 0.5f*scale*p1.y() - 0.5f*scale*p2.y(),
+                           visualCenter.z() + 0.5f*scale*p1.z() - 0.5f*scale*p2.z());
+                           
+  m_PlaneSource->SetPoint2(visualCenter.x() - 0.5f*scale*p1.x() + 0.5f*scale*p2.x(),
+                           visualCenter.y() - 0.5f*scale*p1.y() + 0.5f*scale*p2.y(),
+                           visualCenter.z() - 0.5f*scale*p1.z() + 0.5f*scale*p2.z());
+}
+
 } // namespace Vtk
 } // namespace uLib
\ No newline at end of file
diff --git a/src/Vtk/HEP/Detectors/vtkDetectorChamber.h b/src/Vtk/HEP/Detectors/vtkDetectorChamber.h
index 69dae8c..6c2f128 100644
--- a/src/Vtk/HEP/Detectors/vtkDetectorChamber.h
+++ b/src/Vtk/HEP/Detectors/vtkDetectorChamber.h
@@ -39,6 +39,8 @@
 #include <vtkBoxWidget.h>
 #include <vtkTransformPolyDataFilter.h>
 
+class vtkPlaneSource;
+
 namespace uLib {
 namespace Vtk {
 
@@ -53,6 +55,12 @@ public:
   virtual ~vtkDetectorChamber();
 
   Content *GetContent();
+
+  virtual void contentUpdate() override;
+
+protected:
+  vtkActor *m_PlaneActor;
+  vtkPlaneSource *m_PlaneSource;
 };
 
 } // namespace Vtk