From dbb5f2493360e22f49f2eb3219f12f96d9784b47 Mon Sep 17 00:00:00 2001
From: AndreaRigoni <andrea.rigoni@igi.cnr.it>
Date: Thu, 19 Mar 2026 14:18:31 +0000
Subject: [PATCH] fix zoom to selected

---
 src/Vtk/vtkViewport.cpp | 70 +++++++++++++++++++++++++----------------
 src/Vtk/vtkViewport.h   |  1 +
 2 files changed, 44 insertions(+), 27 deletions(-)

diff --git a/src/Vtk/vtkViewport.cpp b/src/Vtk/vtkViewport.cpp
index 5e6ab2e..c6a8c2e 100644
--- a/src/Vtk/vtkViewport.cpp
+++ b/src/Vtk/vtkViewport.cpp
@@ -190,38 +190,50 @@ void Viewport::SetupPipeline(vtkRenderWindowInteractor* iren)
     iren->AddObserver(vtkCommand::LeftButtonPressEvent, clickCallback);
 
     // Keyboard events for widget coordinate frame
-    vtkNew<vtkCallbackCommand> keyCallback;
-    keyCallback->SetClientData(this);
-    keyCallback->SetCallback([](vtkObject* caller, unsigned long, void* clientdata, void*){
+    m_KeyCallback = vtkSmartPointer<vtkCallbackCommand>::New();
+    m_KeyCallback->SetClientData(this);
+    m_KeyCallback->SetCallback([](vtkObject* caller, unsigned long, void* clientdata, void*){
         auto* iren = static_cast<vtkRenderWindowInteractor*>(caller);
         auto* self = static_cast<Viewport*>(clientdata);
         
-        if (!self->m_HandlerWidget || !self->m_HandlerWidget->GetEnabled()) return;
-        
         std::string key = iren->GetKeySym();
-        if (key == "l") {
-          self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::LOCAL);
-          std::cout << "Widget Frame: LOCAL" << std::endl;
+        bool handled = false;
+
+        if (self->m_HandlerWidget && self->m_HandlerWidget->GetEnabled()) {
+            if (key == "l") {
+                self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::LOCAL);
+                std::cout << "Widget Frame: LOCAL" << std::endl;
+                handled = true;
+            }
+            else if (key == "g") {
+                self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::GLOBAL);
+                std::cout << "Widget Frame: GLOBAL" << std::endl;
+                handled = true;
+            }
+            else if (key == "c") {
+                self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::CENTER);
+                std::cout << "Widget Frame: CENTER" << std::endl;
+                handled = true;
+            }
+            else if (key == "k") {
+                self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::CENTER_LOCAL);
+                std::cout << "Widget Frame: CENTER_LOCAL" << std::endl;
+                handled = true;
+            }
         }
-        else if (key == "g") {
-          self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::GLOBAL);
-          std::cout << "Widget Frame: GLOBAL" << std::endl;
+
+        if (key == "f") {
+            self->ZoomSelected();
+            handled = true;
         }
-        else if (key == "c") {
-          self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::CENTER);
-          std::cout << "Widget Frame: CENTER" << std::endl;
+
+        if (handled) {
+            self->m_KeyCallback->SetAbortFlag(1);
+            iren->Render();
         }
-        else if (key == "k") {
-          self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::CENTER_LOCAL);
-          std::cout << "Widget Frame: CENTER_LOCAL" << std::endl;
-        }
-        else if (key == "s") {
-          self->ZoomSelected();
-        }
-        
-        iren->Render();
     });
-    iren->AddObserver(vtkCommand::KeyPressEvent, keyCallback);
+    iren->AddObserver(vtkCommand::KeyPressEvent, m_KeyCallback, 1.0);
+    iren->AddObserver(vtkCommand::CharEvent, m_KeyCallback, 1.0);
 }
 
 void Viewport::Reset()
@@ -262,14 +274,18 @@ void Viewport::ZoomSelected()
     
     if (bounds[0] > bounds[1]) return; // Invalid bounds
 
-    // Expand bounds by 1.5 from center
+    // Expand bounds by a factor from center (e.g. 2.0 to have some margin)
     double center[3] = {(bounds[0] + bounds[1]) / 2.0, (bounds[2] + bounds[3]) / 2.0, (bounds[4] + bounds[5]) / 2.0};
     double h_ext[3] =  {(bounds[1] - bounds[0]) / 2.0, (bounds[3] - bounds[2]) / 2.0, (bounds[5] - bounds[4]) / 2.0};
     
+    // Ensure a minimum size to avoid camera issues with flat/point objects
+    double max_h = std::max({h_ext[0], h_ext[1], h_ext[2], 0.1});
+    
     double newBounds[6];
     for (int i=0; i<3; ++i) {
-        newBounds[2*i]   = center[i] - 1.5 * h_ext[i];
-        newBounds[2*i+1] = center[i] + 1.5 * h_ext[i];
+        double current_h = std::max(h_ext[i], max_h * 0.1); 
+        newBounds[2*i]   = center[i] - 2.5 * current_h;
+        newBounds[2*i+1] = center[i] + 2.5 * current_h;
     }
     
     m_Renderer->ResetCamera(newBounds);
diff --git a/src/Vtk/vtkViewport.h b/src/Vtk/vtkViewport.h
index 36d1c18..bb488d4 100644
--- a/src/Vtk/vtkViewport.h
+++ b/src/Vtk/vtkViewport.h
@@ -91,6 +91,7 @@ protected:
     vtkSmartPointer<vtkHandlerWidget>            m_HandlerWidget;
     std::vector<Puppet*>                         m_Puppets;
     vtkSmartPointer<vtkCellPicker>               m_Picker;
+    vtkSmartPointer<vtkCallbackCommand>          m_KeyCallback;
 };
 
 } // namespace Vtk