Campbell Barton
8d2cb5bea4
This changes how the BGE classes and Python work together, which hasnt changed since blender went opensource. The main difference is PyObjectPlus - the base class for most game engine classes, no longer inherit from PyObject, and cannot be cast to a PyObject. This has the advantage that the BGE does not have to keep 2 reference counts valid for C++ and Python. Previously C++ classes would never be freed while python held a reference, however this reference could be problematic eg: a GameObject that isnt in a scene anymore should not be used by python, doing so could even crash blender in some cases. Instead PyObjectPlus has a member "PyObject *m_proxy" which is lazily initialized when python needs it. m_proxy reference counts are managed by python, though it should never be freed while the C++ class exists since it holds a reference to avoid making and freeing it all the time. When the C++ class is free'd it sets the m_proxy reference to NULL, If python accesses this variable it will raise a RuntimeError, (check the isValid attribute to see if its valid without raising an error). - This replaces the m_zombie bool and IsZombie() tests added recently. In python return values that used to be.. return value->AddRef(); Are now return value->GetProxy(); or... return value->NewProxy(true); // true means python owns this C++ value which will be deleted when the PyObject is freed
6.4 KiB
6.4 KiB