From c0c9f04c045e38e1955d098e189216caa8760b8c Mon Sep 17 00:00:00 2001
From: Pasukhin Dmitry <dpasukhi@opencascade.com>
Date: Sun, 9 Mar 2025 00:07:17 +0000
Subject: [PATCH] Visualization - AIS_Shape bounding box re-computation is not
 working properly #422

Fixed issue with bounding box cleaning algorithm that was causing the bounding box to be only increased.
Now the bounding box is increased and decreased to fit the shape.
---
 src/AIS/AIS_Shape.cxx    |  2 ++
 tests/v3d/bugs/bug_gh421 | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 tests/v3d/bugs/bug_gh421

diff --git a/src/AIS/AIS_Shape.cxx b/src/AIS/AIS_Shape.cxx
index c734d11a63..065e01be9c 100644
--- a/src/AIS/AIS_Shape.cxx
+++ b/src/AIS/AIS_Shape.cxx
@@ -735,6 +735,8 @@ const Bnd_Box& AIS_Shape::BoundingBox()
 
   if (myCompBB)
   {
+    // Clear the bounding box to re-compute it.
+    myBB.SetVoid();
     BRepBndLib::Add(myshape, myBB, false);
     myCompBB = Standard_False;
   }
diff --git a/tests/v3d/bugs/bug_gh421 b/tests/v3d/bugs/bug_gh421
new file mode 100644
index 0000000000..183eecbb3a
--- /dev/null
+++ b/tests/v3d/bugs/bug_gh421
@@ -0,0 +1,20 @@
+puts "============"
+puts "Visualization - Bounding box is not decreasing for mode 2 #421"
+puts "============"
+puts ""
+
+pload MODELING VISUALIZATION
+vclear
+
+box b 100 200 300
+vinit View1
+vdisplay b -dispMode 2
+# OK
+box b 10 200 300
+vdisplay b -dispMode 2
+
+vfit
+
+checkcolor 243 2 0 0 0
+
+vdump $::imagedir/${::casename}.png