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
Other small changes...
- KX_Camera and KX_Light didnt have get/setitem access in their PyType definition.
- CList.from_id() error checking for a long was checking for -1 against an unsigned value (own fault)
- CValue::SpecialRelease was incrementing an int for no reason.
- renamed m_attrlist to m_attr_dict since its a PyDict type.
- removed custom getattro/setattro functions for KX_Scene and KX_GameObject, use py_base_getattro, py_base_setattro for all subclasses of PyObjectPlus.
- lowercase windows.h in VideoBase.cpp for cross compiling.
added defines PY_SET_ATTR_FAIL, PY_SET_ATTR_MISSING and PY_SET_ATTR_SUCCESS
This is useful when objects that have user defined attributes (GameObject and Scene)
When calling setattr on the parent, a return value of PY_SET_ATTR_FAIL means the attribute exists but failed to be set, so don't set the custom attribute.
- Make BGE's ListValue types convert to python lists for printing since the CValue GetText() function didnt work well- printing lists as [,,,,,] for scene objects and mesh materials for eg.
- Check attributes are descriptor types before casting.
- py_getattr_dict use the Type dict rather then Method and Attribute array.
Use each types dictionary to store attributes PyAttributeDef's so it uses pythons hash lookup (which it was already doing for methods) rather then doing a string lookup on the array each time.
This also means attributes can be found in the type without having to do a dir() on the instance.
- Initialize python types with PyType_Ready, which adds methods to the type dictionary.
- use Pythons get/setattro (uses a python string for the attribute rather then char*). Using basic C strings seems nice but internally python converts them to python strings and discards them for most functions that accept char arrays.
- Method lookups use the PyTypes dictionary (should be faster then Py_FindMethod)
- Renamed __getattr -> py_base_getattro, _getattr -> py_getattro, __repr -> py_base_repr, py_delattro, py_getattro_self etc.
From here is possible to put all the parent classes methods into each python types dictionary to avoid nested lookups (api has 4 levels of lookups in some places), tested this but its not ready yet.
Simple tests for getting a method within a loop show this to be between 0.5 and 3.2x faster then using Py_FindMethod()
Added the method into the PyType so python knows about the methods (its supposed to work this way).
This means in the future the api can use PyType_Ready() to store the methods in the types dictionary.
Python3 removes Py_FindMethod and we should not be using it anyway since its not that efficient.
Python dir(ob) for game types now includes attributes names,
* Use "__dict__" rather then "__methods__" attribute to be Python 3.0 compatible
* Added _getattr_dict() for getting the method and attribute names from a PyObject, rather then building it in the macro.
* Added place holder *::Attribute array, needed for the _getattr_up macro.
- variables that shadow vers declared earlier
- Py_Fatal print an error to the stderr
- gcc was complaining about the order of initialized vars (for classes)
- const return values for ints and bools didnt do anything.
- braces for ambiguous if statements
Use 'const char *' rather then the C++ 'STR_String' type for the attribute identifier of python attributes.
Each attribute and method access from python was allocating and freeing the string.
A simple test with getting an attribute a loop shows this speeds up attribute lookups a bit over 2x.
scene.getObjectList()[-1] works like a python sequence.
removed some STR_String creation that was only used to do comparisons, in a simple expressions benchmark this made logic use 4% less overall.
* Value clamping to min/max is now supported as an option for integer, float
and string attribute (for string clamping=trim to max length)
* Post check function now take PyAttributeDef parameter so that more
generic function can be written.
* Definition of SCA_ILogicBrick::CheckProperty() function to check that
a string attribute contains a valid property name of the parent game object.
* Definition of enum attribute vi KX_PYATTRIBUTE_ENUM... macros.
Enum are handled just like integer but to be totally paranoid, the sizeof()
of the enum member is check at run time to match integer size.
* More bricks updated to use the framework.
I'm getting this error now:
GPG_Application.cpp: In member function 'void GPG_Application::stopEngine()':
/System/Library/Frameworks/Python.framework/Versions/2.3/include/python2.3/marshal.h:12: error: too many arguments to function 'PyObject* PyMarshal_WriteObjectToString(PyObject*)'
GPG_Application.cpp:720: error: at this point in file
Are we offically not supporint older versions of python now? :)
Kent
* removed macros that were not used much, some misleading.
* removed error string setting calls that overwrote the error set by PyArg_ParseTuple with a less useful one.
* use python macros Py_RETURN_NONE, Py_RETURN_TRUE, Py_RETURN_FALSE
fixed a python related bug with physics contraints
fixed some line-ending problem with blenderbuttons.c
makefile/scons/projectfiles need to add source/gameengine/Ketsji/KX_VehicleWrapper.cpp
