From e70cecef3e012f242dbee080e67e99e8bf4ece2a Mon Sep 17 00:00:00 2001
From: Sverre Briseid <Sverre.Briseid@sintef.no>
Date: Sat, 23 Nov 2024 10:29:52 +0100
Subject: [PATCH] Enabled support for using scrool wheel to zoom.

---
 viewlib/include/GoTools/viewlib/gvView.h |  2 ++
 viewlib/src/gvView.C                     | 18 ++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/viewlib/include/GoTools/viewlib/gvView.h b/viewlib/include/GoTools/viewlib/gvView.h
index 53ee55ca..41e1e5ae 100644
--- a/viewlib/include/GoTools/viewlib/gvView.h
+++ b/viewlib/include/GoTools/viewlib/gvView.h
@@ -199,6 +199,8 @@ public slots:
     /// zoom and rotate the camera.
     virtual void mouseMoveEvent(QMouseEvent* e);
 
+    virtual void wheelEvent(QWheelEvent* e);
+
     virtual bool get3Dpoint(int mousex, int mousey, Vector3D &objpt);
 
     void drawOverlay();
diff --git a/viewlib/src/gvView.C b/viewlib/src/gvView.C
index de795003..ef5d26d9 100644
--- a/viewlib/src/gvView.C
+++ b/viewlib/src/gvView.C
@@ -967,6 +967,24 @@ void gvView::mouseMoveEvent(QMouseEvent* e)
     updateGL();
 }
 
+
+//===========================================================================
+void gvView::wheelEvent(QWheelEvent* e)
+//===========================================================================
+{
+    // Zoom the scene with scroll wheel
+    double dist = 0.0;
+    camera_.getDistance(dist);
+
+    // Get the delta of the wheel, and adjust the zoom factor
+    int delta = -e->angleDelta().y(); // y() is typically used for vertical scrolling
+    double zoomFactor = 1.0 - 0.001 * delta; // Adjust the zoom speed to your preference
+
+    camera_.setDistance(dist * zoomFactor);
+
+    updateGL();
+}
+
 //===========================================================================
 void gvView::focusOnBox()
 //===========================================================================