BGE Python API

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

1 files changed, 1 insertions, 2 deletions

diff --git a/source/gameengine/Ketsji/KX_PolygonMaterial.cpp b/source/gameengine/Ketsji/KX_PolygonMaterial.cpp
index 056442f77d9..bf1fbe386e6 100644
--- a/source/gameengine/Ketsji/KX_PolygonMaterial.cpp
+++ b/source/gameengine/Ketsji/KX_PolygonMaterial.cpp
@@ -98,8 +98,7 @@ bool KX_PolygonMaterial::Activate(RAS_IRasterizer* rasty, TCachingInfo& cachingI
 	{
 		PyObject *pyRasty = PyCObject_FromVoidPtr((void*)rasty, NULL);	/* new reference */
 		PyObject *pyCachingInfo = PyCObject_FromVoidPtr((void*) &cachingInfo, NULL); /* new reference */
-		
-		PyObject *ret = PyObject_CallMethod(m_pymaterial, "activate", "(NNO)", pyRasty, pyCachingInfo, (PyObject*) this);
+		PyObject *ret = PyObject_CallMethod(m_pymaterial, "activate", "(NNO)", pyRasty, pyCachingInfo, (PyObject*) this->m_proxy);
 		if (ret)
 		{
 			bool value = PyInt_AsLong(ret);