Fix crash when camera x/y/z scale is set to zero

Resets the scale value to original if the target object is camera. Fix was
done in InspectorControlModel in order to be able to also immediately
update the reset value in inspector window, as opposed to silently
discarding invalid value later in the stack.

Change-Id: I1433c7397efb470e724593d3d85f05372bd31db0
Task-Id: QT3DS-384
Reviewed-by: Miikka Heikkinen <miikka.heikkinen@qt.io>
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/Authoring/Studio/Palettes/Inspector/InspectorControlModel.cpp b/src/Authoring/Studio/Palettes/Inspector/InspectorControlModel.cpp
index f3d6d304..3be1c395 100644
--- a/src/Authoring/Studio/Palettes/Inspector/InspectorControlModel.cpp
+++ b/src/Authoring/Studio/Palettes/Inspector/InspectorControlModel.cpp
@@ -810,6 +810,22 @@ void InspectorControlModel::setPropertyValue(long instance, int handle, const QV
         return;
     }
 
+    // If the user enters 0.0 to any (x, y, z) values of camera scale,
+    // we reset the value back to original, because zero scale factor will crash
+    // camera-specific inverse matrix math. (Additionally, scale of zero for a camera
+    // is generally not useful anyway.) We could silently discard zero values also deeper in the
+    // value setter code, but then the inspector panel value would not be updated as opposed
+    // to both rejecting invalid and resetting the original value here.
+    const auto studio = g_StudioApp.GetCore()->GetDoc()->GetStudioSystem();
+    EStudioObjectType theType = studio->GetClientDataModelBridge()->GetObjectType(instance);
+
+    if (theType == EStudioObjectType::OBJTYPE_CAMERA &&
+            studio->GetPropertySystem()->GetName(handle) == Q3DStudio::CString("scale")) {
+        const QVector3D theFloat3 = qt3dsdm::get<QVector3D>(v);
+        if (theFloat3.x() == 0.0f || theFloat3.y() == 0.0f || theFloat3.z() == 0.0f )
+            v = oldValue;
+    }
+
     if (!commit && m_modifiedProperty.first == 0) {
         m_modifiedProperty.first = instance;
         m_modifiedProperty.second = handle;