vtkPythonUtil.cxx

/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkPythonUtil.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/

// This include allows VTK to build on some platforms with broken Python
// header files.
#include "vtkPythonUtil.h"

#include "vtkSystemIncludes.h"

#include "vtkDataArray.h"
#include "vtkObject.h"
#include "vtkObjectFactory.h"
#include "vtkSmartPointerBase.h"
#include "vtkTimeStamp.h"
#include "vtkWindows.h"

#include <vtksys/ios/sstream>
#include <vtkstd/map>
#include <vtkstd/string>

// Silent warning like
// "dereferencing type-punned pointer will break strict-aliasing rules"
// it happens because this kind of expression: (long *)&ptr
// pragma GCC diagnostic is available since gcc>=4.2
#if defined(__GNUG__) && (__GNUC__>4) || (__GNUC__==4 && __GNUC_MINOR__>=2)
#pragma GCC diagnostic ignored "-Wstrict-aliasing"
#endif

#if defined ( _MSC_VER )
#  define vtkConvertPtrToLong(x) ((long)(PtrToUlong(x)))
#else
#  define vtkConvertPtrToLong(x) ((long)(x))
#endif

// The following macro is used to supress missing initializer
// warnings.  Python documentation says these should not be necessary.
// We define it as a macro in case the length needs to change across
// python versions.
#if   PY_VERSION_HEX >= 0x02060000 // for tp_version_tag
#define VTK_PYTHON_UTIL_SUPRESS_UNINITIALIZED \
  0,0,0,0,0, 0,0,0,0,0, 0,0,0,0,0, 0,0,0,0,0, 0, 0,
#elif   PY_VERSION_HEX >= 0x02030000
#define VTK_PYTHON_UTIL_SUPRESS_UNINITIALIZED \
  0,0,0,0,0, 0,0,0,0,0, 0,0,0,0,0, 0,0,0,0,0, 0,
#elif PY_VERSION_HEX >= 0x02020000
#define VTK_PYTHON_UTIL_SUPRESS_UNINITIALIZED \
  0,0,0,0,0, 0,0,0,0,0, 0,0,0,0,0, 0,0,0,0,0,
#else
#define VTK_PYTHON_UTIL_SUPRESS_UNINITIALIZED
#endif

#if PY_VERSION_HEX < 0x02050000
  typedef int Py_ssize_t;
#endif

//#define VTKPYTHONDEBUG

//--------------------------------------------------------------------
// There are two hash tables associated with the Python wrappers

class vtkPythonUtil
{
public:
  vtkPythonUtil();
  ~vtkPythonUtil();

  vtkstd::map<vtkSmartPointerBase, PyObject*> *ObjectHash;
  vtkstd::map<vtkstd::string, PyObject*> *ClassHash;
  vtkstd::map<vtkstd::string, PyVTKSpecialTypeInfo> *SpecialTypeHash;
};

//--------------------------------------------------------------------
vtkPythonUtil *vtkPythonHash = NULL;

//--------------------------------------------------------------------
vtkPythonUtil::vtkPythonUtil()
{
  this->ObjectHash = new vtkstd::map<vtkSmartPointerBase, PyObject*>;
  this->ClassHash = new vtkstd::map<vtkstd::string, PyObject*>;;
  this->SpecialTypeHash =
    new vtkstd::map<vtkstd::string, PyVTKSpecialTypeInfo>;
}

//--------------------------------------------------------------------
vtkPythonUtil::~vtkPythonUtil()
{
  delete this->ObjectHash;
  delete this->ClassHash;
  delete this->SpecialTypeHash;
}

//--------------------------------------------------------------------
extern "C" void vtkPythonHashDelete()
{
  delete vtkPythonHash;
  vtkPythonHash = 0;
}

//--------------------------------------------------------------------
static PyObject *PyVTKObject_PyString(PyVTKObject *self)
{
  PyObject *func = PyObject_GetAttrString((PyObject *)self, (char*)"__str__");

  if (func)
    {
    PyObject *res = PyEval_CallObject(func, (PyObject *)NULL);
    Py_DECREF(func);
    return res;
    }
  PyErr_Clear();

  vtksys_ios::ostringstream vtkmsg_with_warning_C4701;
  self->vtk_ptr->Print(vtkmsg_with_warning_C4701);
  vtkmsg_with_warning_C4701.put('\0');
  PyObject *res = PyString_FromString(vtkmsg_with_warning_C4701.str().c_str());
  return res;
}

//--------------------------------------------------------------------
static PyObject *PyVTKObject_PyRepr(PyVTKObject *self)
{
  PyObject *func = PyObject_GetAttrString((PyObject *)self, (char*)"__repr__");

  if (func)
    {
    PyObject *res = PyEval_CallObject(func, (PyObject *)NULL);
    Py_DECREF(func);
    return res;
    }
  PyErr_Clear();

  char buf[255];
  sprintf(buf,"<%s.%s %s at %p>",
          PyString_AsString(self->vtk_class->vtk_module),
          PyString_AsString(self->vtk_class->vtk_name),
          self->ob_type->tp_name,self);
  
  return PyString_FromString(buf);
}

//--------------------------------------------------------------------
int PyVTKObject_PySetAttr(PyVTKObject *self, PyObject *attr,
                          PyObject *value)
{
  char *name = PyString_AsString(attr);

  if (name[0] == '_' && name[1] == '_')
    {
    if (strcmp(name, "__dict__") == 0)
      {
      PyErr_SetString(PyExc_RuntimeError,
                      "__dict__ is a read-only attribute");
      return -1;
      }
    if (strcmp(name, "__class__") == 0)
      {
      PyErr_SetString(PyExc_RuntimeError,
                      "__class__ is a read-only attribute");
      return -1;
      }
    }
  
  if (value)
    {
    PyObject *func = self->vtk_class->vtk_setattr;
    if (func)
      {
      PyObject *args = Py_BuildValue((char*)"(OOO)", self, attr, value);
      PyObject *res = PyEval_CallObject(func, args);
      Py_DECREF(args);
      if (res)
        {
        Py_DECREF(res);
        return 0;
        }
      return -1;
      }
    return PyDict_SetItem(self->vtk_dict, attr, value);
    }
  else
    {
    PyObject *func = self->vtk_class->vtk_delattr;
    if (func)
      {
      PyObject *args = Py_BuildValue((char*)"(OO)", self, attr);
      PyObject *res = PyEval_CallObject(func, args);
      Py_DECREF(args);
      if (res)
        {
        Py_DECREF(res);
        return 0;
        }
      return -1;
      }
    int rv = PyDict_DelItem(self->vtk_dict, attr);
    if (rv < 0)
      {
      PyErr_SetString(PyExc_AttributeError,
                      "delete non-existing class attribute");
      }
    return rv;
    }
}

//--------------------------------------------------------------------
static PyObject *PyVTKObject_PyGetAttr(PyVTKObject *self, PyObject *attr)
{
  char *name = PyString_AsString(attr);
  PyVTKClass *pyclass = self->vtk_class;
  PyObject *bases;
  PyObject *value;

  if ((value = PyDict_GetItem(self->vtk_dict, attr)))
    {
    Py_INCREF(value);
    return value;
    }

  if (name[0] == '_')
    {
    if (strcmp(name,"__class__") == 0)
      {
      Py_INCREF(self->vtk_class);
      return (PyObject *)self->vtk_class;
      }
      
    if (strcmp(name,"__this__") == 0)
      {
      char buf[256];
      sprintf(buf,"p_%s", self->vtk_ptr->GetClassName());
      return PyString_FromString(vtkPythonManglePointer(self->vtk_ptr,buf));
      }

    if (strcmp(name,"__doc__") == 0)
      {
      Py_INCREF(pyclass->vtk_doc);
      return pyclass->vtk_doc;
      }

    if (strcmp(name,"__dict__") == 0)
      {
      Py_INCREF(self->vtk_dict);
      return self->vtk_dict;
      }
    }

  while (pyclass != NULL)
    {
    PyMethodDef *meth;

    if (pyclass->vtk_dict == NULL)
      {
      pyclass->vtk_dict = PyDict_New();

      for (meth = pyclass->vtk_methods; meth && meth->ml_name; meth++)
        {
        PyDict_SetItemString(pyclass->vtk_dict,meth->ml_name,
                             PyCFunction_New(meth, (PyObject *)pyclass));
        }
      }

    value = PyDict_GetItem(pyclass->vtk_dict, attr);
    
    if (value)
      {
      if (PyCFunction_Check(value))
        {
        return PyCFunction_New(((PyCFunctionObject *)value)->m_ml,
                               (PyObject *)self);
        }
      else if (PyCallable_Check(value))
        {
        return PyMethod_New(value, (PyObject *)self,
                            (PyObject *)self->vtk_class);
        }
      Py_INCREF(value);
      return value;
      }

    bases = ((PyVTKClass *)pyclass)->vtk_bases;
    pyclass = NULL;
    if (PyTuple_Size(bases))
      {
      pyclass = (PyVTKClass *)PyTuple_GetItem(bases,0);
      }
    }

  // try the __getattr__ attribute if set
  pyclass = self->vtk_class;
  if (pyclass->vtk_getattr)
    {
    PyObject *args = Py_BuildValue((char*)"(OO)", self, attr);
    PyObject *res = PyEval_CallObject(pyclass->vtk_getattr, args);
    Py_DECREF(args);
    return res;
    }

  PyErr_SetString(PyExc_AttributeError, name);
  return NULL;
}

//--------------------------------------------------------------------
static void PyVTKObject_PyDelete(PyVTKObject *self)
{
#if PY_VERSION_HEX >= 0x02010000
  if (self->vtk_weakreflist != NULL)
    {
    PyObject_ClearWeakRefs((PyObject *) self);
    }
#endif

  // A python object owning a VTK object reference is getting
  // destroyed.  Remove the python object's VTK object reference.
  vtkPythonDeleteObjectFromHash((PyObject *)self);

  Py_DECREF((PyObject *)self->vtk_class);
  Py_DECREF(self->vtk_dict);
#if (PY_MAJOR_VERSION >= 2)
  PyObject_Del(self);
#else
  PyMem_DEL(self);
#endif  
}

//--------------------------------------------------------------------
// The following methods and struct define the "buffer" protocol
// for PyVTKObject, so that python can read from a vtkDataArray.
// This is particularly useful for NumPy.

//--------------------------------------------------------------------
static Py_ssize_t
PyVTKObject_AsBuffer_GetSegCount(
  PyObject *pself, Py_ssize_t *lenp)
{
  PyVTKObject *self = (PyVTKObject*)pself;
  vtkDataArray *da = vtkDataArray::SafeDownCast(self->vtk_ptr);
  if (da)
    {
    if (lenp)
      {
      *lenp = da->GetNumberOfTuples()*
        da->GetNumberOfComponents()*
        da->GetDataTypeSize();
      }

    return 1;
    }

  if (lenp)
    {
    *lenp = 0;
    }
  return 0;
}

//--------------------------------------------------------------------
static Py_ssize_t
PyVTKObject_AsBuffer_GetReadBuf(
  PyObject *pself, Py_ssize_t segment, void **ptrptr)
{
  if (segment != 0) 
    {
    PyErr_SetString(PyExc_ValueError,
                    "accessing non-existing array segment");
    return -1;
    }

  PyVTKObject *self = (PyVTKObject*)pself;
  vtkDataArray *da = vtkDataArray::SafeDownCast(self->vtk_ptr);
  if (da)
    {
    *ptrptr = da->GetVoidPointer(0);
    return da->GetNumberOfTuples()*
      da->GetNumberOfComponents()*
      da->GetDataTypeSize();
    }
  return -1;
}

//--------------------------------------------------------------------
static Py_ssize_t
PyVTKObject_AsBuffer_GetWriteBuf(
  PyObject *pself, Py_ssize_t segment, void **ptrptr)
{
  return PyVTKObject_AsBuffer_GetReadBuf(pself, segment, ptrptr);
}

//--------------------------------------------------------------------
static Py_ssize_t
PyVTKObject_AsBuffer_GetCharBuf(PyObject *, Py_ssize_t , const char **)
{
  return -1;
}

//--------------------------------------------------------------------
static PyBufferProcs PyVTKObject_AsBuffer = {
#if PY_VERSION_HEX >= 0x02050000
  (readbufferproc)PyVTKObject_AsBuffer_GetReadBuf,     // bf_getreadbuffer
  (writebufferproc)PyVTKObject_AsBuffer_GetWriteBuf,   // bf_getwritebuffer
  (segcountproc)PyVTKObject_AsBuffer_GetSegCount,      // bf_getsegcount
  (charbufferproc)PyVTKObject_AsBuffer_GetCharBuf,     // bf_getcharbuffer
 #if PY_VERSION_HEX >= 0x02060000
  (getbufferproc)0,                                    // bf_getbuffer
  (releasebufferproc)0                                 // bf_releasebuffer
 #endif
#else
  (getreadbufferproc)PyVTKObject_AsBuffer_GetReadBuf,  // bf_getreadbuffer
  (getwritebufferproc)PyVTKObject_AsBuffer_GetWriteBuf,// bf_getwritebuffer
  (getsegcountproc)PyVTKObject_AsBuffer_GetSegCount,   // bf_getsegcount
  (getcharbufferproc)PyVTKObject_AsBuffer_GetCharBuf,  // bf_getcharbuffer
#endif
};

//--------------------------------------------------------------------
static PyTypeObject PyVTKObjectType = {
  PyObject_HEAD_INIT(&PyType_Type)
  0,
  (char*)"vtkobject",                    // tp_name
  sizeof(PyVTKObject),                   // tp_basicsize
  0,                                     // tp_itemsize
  (destructor)PyVTKObject_PyDelete,      // tp_dealloc
  (printfunc)0,                          // tp_print
  (getattrfunc)0,                        // tp_getattr
  (setattrfunc)0,                        // tp_setattr
  (cmpfunc)0,                            // tp_compare
  (reprfunc)PyVTKObject_PyRepr,          // tp_repr
  0,                                     // tp_as_number 
  0,                                     // tp_as_sequence
  0,                                     // tp_as_mapping
  (hashfunc)0,                           // tp_hash
  (ternaryfunc)0,                        // tp_call
  (reprfunc)PyVTKObject_PyString,        // tp_string
  (getattrofunc)PyVTKObject_PyGetAttr,   // tp_getattro
  (setattrofunc)PyVTKObject_PySetAttr,   // tp_setattro
  &PyVTKObject_AsBuffer,                 // tp_as_buffer
#if PY_VERSION_HEX >= 0x02010000
  Py_TPFLAGS_HAVE_WEAKREFS,              // tp_flags
#else
  0,                                     // tp_flags
#endif 
  (char*)"A VTK object.  Special attributes are:  __class__ (the class that this object belongs to), __dict__ (user-controlled attributes), __doc__ (the docstring for the class), __methods__ (a list of all methods for this object), and __this__ (a string that contains the hexidecimal address of the underlying VTK object)",  // tp_doc
  0,                                     // tp_traverse
  0,                                     // tp_clear
  0,                                     // tp_richcompare
#if PY_VERSION_HEX >= 0x02010000
  offsetof(PyVTKObject, vtk_weakreflist),// tp_weaklistoffset
#else
  0,                                     // tp_weaklistoffset
#endif
  VTK_PYTHON_UTIL_SUPRESS_UNINITIALIZED
};

int PyVTKObject_Check(PyObject *obj)
{
  return (obj->ob_type == &PyVTKObjectType);
}

PyObject *PyVTKObject_New(PyObject *pyvtkclass, vtkObjectBase *ptr)
{
  PyVTKClass *vtkclass = (PyVTKClass *)pyvtkclass;
  bool haveRef = false;
  if (!ptr)
    {
    // Create a new instance of this class since we were not given one.
    if(vtkclass->vtk_new)
      {
      ptr = vtkclass->vtk_new();
      haveRef = true;
      }
    else
      {
      PyErr_SetString(
        PyExc_TypeError,
        (char*)"this is an abstract class and cannot be instantiated");
      return 0;
      }
    }
#if (PY_MAJOR_VERSION >= 2)
  PyVTKObject *self = PyObject_New(PyVTKObject, &PyVTKObjectType);
#else
  PyVTKObject *self = PyObject_NEW(PyVTKObject, &PyVTKObjectType);
#endif  
  self->vtk_ptr = ptr;
  PyObject *cls = NULL;
  vtkstd::map<vtkstd::string, PyObject*>::iterator i =
    vtkPythonHash->ClassHash->find(ptr->GetClassName());
  if (i != vtkPythonHash->ClassHash->end())
    {
    cls = i->second;
    }
  self->vtk_class = (PyVTKClass *)cls;
  
  // If the class was not in the dictionary (i.e. if there is no 'python'
  // level class to support the VTK level class) we fall back to this.
  if (self->vtk_class == NULL || vtkclass->vtk_methods == NULL)
    {
    self->vtk_class = vtkclass;
    }
  
  Py_INCREF(self->vtk_class);
  
  self->vtk_dict = PyDict_New();

#if PY_VERSION_HEX >= 0x02010000
  self->vtk_weakreflist = NULL;
#endif

  // A python object owning a VTK object reference is getting
  // created.  Add the python object's VTK object reference.
  vtkPythonAddObjectToHash((PyObject *)self, ptr);

  // The hash now owns a reference so we can free ours.
  if (haveRef)
    {
    ptr->Delete();
    }

  return (PyObject *)self;
}

//--------------------------------------------------------------------
static PyObject *PyVTKClass_PyString(PyVTKClass *self)
{
  char buf[255];
  sprintf(buf,"%s.%s",
          PyString_AsString(self->vtk_module),
          PyString_AsString(self->vtk_name));

  return PyString_FromString(buf);
}

//--------------------------------------------------------------------
static PyObject *PyVTKClass_PyRepr(PyVTKClass *self)
{
  char buf[255];
  sprintf(buf,"<%s %s.%s at %p>",self->ob_type->tp_name,
          PyString_AsString(self->vtk_module),
          PyString_AsString(self->vtk_name),
          self);
  
  return PyString_FromString(buf);
}

//--------------------------------------------------------------------
static PyObject *PyVTKClass_PyCall(PyVTKClass *self, PyObject *arg,
                                   PyObject *kw)
{
  static PyObject *initstr = 0;

  if (((PyVTKClass *)self)->vtk_dict)
    {
    if (initstr == 0)
      {
      initstr = PyString_FromString("__init__");
      }

    PyObject *initfunc;
    initfunc = PyDict_GetItem(self->vtk_dict, initstr);

    if (initfunc)
      {      
      PyObject *obj = PyVTKObject_New((PyObject *)self,NULL);
      PyObject *cinitfunc = PyVTKObject_PyGetAttr((PyVTKObject *)obj, initstr);
      PyObject *res = PyEval_CallObjectWithKeywords(cinitfunc, arg, kw);
      if (res == NULL)
        {
        Py_DECREF(obj);
        obj = NULL;
        }
      else if (res != Py_None)
        {
        PyErr_SetString(PyExc_TypeError, "__init__() should return None");
        Py_DECREF(obj);
        obj = NULL;
        }
      Py_DECREF(cinitfunc);
      return obj;
      }
    }

  if (kw != NULL)
    {
    PyErr_SetString(PyExc_TypeError,
                    "this function takes no keyword arguments");
    return NULL;
    }
  if (PyArg_ParseTuple(arg,(char*)""))
    {
    return PyVTKObject_New((PyObject *)self, NULL);
    }
  PyErr_Clear();
  if (PyArg_ParseTuple(arg,(char*)"O", &arg))
    {
    return vtkPythonGetObjectFromObject(arg,
                                        PyString_AsString(self->vtk_name));
    }
  PyErr_Clear();
  PyErr_SetString(PyExc_TypeError,
                  "function requires 0 or 1 arguments");

  return NULL;
}

//--------------------------------------------------------------------
static PyObject *PyVTKClass_PyGetAttr(PyVTKClass *self, PyObject *attr)
{
  char *name = PyString_AsString(attr);
  PyVTKClass *pyclass = self;
  PyObject *bases;

  while (pyclass != NULL)
    {
    PyMethodDef *meth;
    PyObject *value;

    if (pyclass->vtk_dict == NULL)
      {
      pyclass->vtk_dict = PyDict_New();

      for (meth = pyclass->vtk_methods; meth && meth->ml_name; meth++)
        {
        PyDict_SetItemString(pyclass->vtk_dict,meth->ml_name,
                             PyCFunction_New(meth, (PyObject *)pyclass));
        }
      }

    value = PyDict_GetItem(pyclass->vtk_dict, attr);
    
    if (value)
      {
      Py_INCREF(value);
      return value;
      }

    bases = pyclass->vtk_bases;
    pyclass = NULL;
    if (PyTuple_Size(bases))
      {
      pyclass = (PyVTKClass *)PyTuple_GetItem(bases,0);
      }
    }

  if (name[0] == '_')
    {
    pyclass = (PyVTKClass *)self;

    if (strcmp(name,"__bases__") == 0)
      {
      Py_INCREF(pyclass->vtk_bases);
      return pyclass->vtk_bases;
      }

    if (strcmp(name,"__name__") == 0)
      {
      Py_INCREF(pyclass->vtk_name);
      return pyclass->vtk_name;
      }

    if (strcmp(name,"__module__") == 0)
      {
      Py_INCREF(pyclass->vtk_module);
      return pyclass->vtk_module;
      }

    if (strcmp(name,"__dict__") == 0 && pyclass->vtk_dict)
      {
      Py_INCREF(pyclass->vtk_dict);
      return pyclass->vtk_dict;
      }
      
    if (strcmp(name,"__doc__") == 0)
      {
      Py_INCREF(pyclass->vtk_doc);
      return pyclass->vtk_doc;
      }
    }

  PyErr_SetString(PyExc_AttributeError, name);
  return NULL;
}

//--------------------------------------------------------------------
static void PyVTKClass_PyDelete(PyVTKClass *self)
{
  Py_XDECREF(self->vtk_bases);
  Py_XDECREF(self->vtk_dict);
  Py_XDECREF(self->vtk_name);

  Py_XDECREF(self->vtk_getattr);
  Py_XDECREF(self->vtk_setattr);
  Py_XDECREF(self->vtk_delattr);

  Py_XDECREF(self->vtk_module);
  Py_XDECREF(self->vtk_doc);
    
#if (PY_MAJOR_VERSION >= 2)
  PyObject_Del(self);
#else
  PyMem_DEL(self);
#endif  
}

//--------------------------------------------------------------------
static PyObject *PyVTKClassMetaType_GetAttr(PyTypeObject *t, char *name)
{
  if (strcmp(name, "__name__") == 0)
    {
    return PyString_FromString(t->tp_name);
    }
  if (strcmp(name, "__doc__") == 0)
    {
    const char *doc = t->tp_doc;
    if (doc != NULL)
      {
      return PyString_FromString(doc);
      }
    Py_INCREF(Py_None);
    return Py_None;
    }
  if (strcmp(name, "__members__") == 0)
    {
    return Py_BuildValue((char*)"[ss]", "__doc__", "__name__");
    }
  PyErr_SetString(PyExc_AttributeError, name);
  return NULL;
}

//--------------------------------------------------------------------
static PyObject *PyVTKClassMetaType_Repr(PyTypeObject *v)
{
  char buf[100];
  sprintf(buf, "<type '%.80s'>", v->tp_name);
  return PyString_FromString(buf);
}

//--------------------------------------------------------------------
static PyObject *PyVTKClass_NewSubclass(PyObject *self, PyObject *args,
                                        PyObject *kw);

//--------------------------------------------------------------------
PyTypeObject PyVTKClassMetaType = {
  PyObject_HEAD_INIT(&PyType_Type)
  0,                        /* Number of items for varobject */
  (char*)"vtkclass type",   /* Name of this type */
  sizeof(PyTypeObject),     /* Basic object size */
  0,                        /* Item size for varobject */
  0,                        /*tp_dealloc*/
  0,                        /*tp_print*/
  (getattrfunc)PyVTKClassMetaType_GetAttr, /*tp_getattr*/
  0,                        /*tp_setattr*/
  0,                        /*tp_compare*/
  (reprfunc)PyVTKClassMetaType_Repr,        /*tp_repr*/
  0,                        /*tp_as_number*/
  0,                        /*tp_as_sequence*/
  0,                        /*tp_as_mapping*/
  0,                        /*tp_hash*/
  (ternaryfunc)PyVTKClass_NewSubclass, /*tp_call*/
  0,                        /*tp_str*/
  0,                        /*tp_xxx1*/
  0,                        /*tp_xxx2*/
  0,                        /*tp_xxx3*/
  0,                        /*tp_xxx4*/
  (char*)"Define the behavior of a particular type of object.",
  0,                        // tp_traverse
  0,                        // tp_clear
  0,                        // tp_richcompare
  0,                        // tp_weaklistoffset
  VTK_PYTHON_UTIL_SUPRESS_UNINITIALIZED
};

//--------------------------------------------------------------------
static PyTypeObject PyVTKClassType = {
  PyObject_HEAD_INIT(&PyVTKClassMetaType)
  0,
  (char*)"vtkclass",                     // tp_name
  sizeof(PyVTKClass),                    // tp_basicsize
  0,                                     // tp_itemsize
  (destructor)PyVTKClass_PyDelete,       // tp_dealloc
  (printfunc)0,                          // tp_print
  (getattrfunc)0,                        // tp_getattr
  (setattrfunc)0,                        // tp_setattr
  (cmpfunc)0,                            // tp_compare
  (reprfunc)PyVTKClass_PyRepr,           // tp_repr
  0,                                     // tp_as_number 
  0,                                     // tp_as_sequence
  0,                                     // tp_as_mapping
  (hashfunc)0,                           // tp_hash
  (ternaryfunc)PyVTKClass_PyCall,        // tp_call
  (reprfunc)PyVTKClass_PyString,         // tp_string
  (getattrofunc)PyVTKClass_PyGetAttr,    // tp_getattro
  (setattrofunc)0,                       // tp_setattro
  0,                                     // tp_as_buffer
  0,                                     // tp_flags
  (char*)"A generator for VTK objects.  Special attributes are: __bases__ (a tuple of base classes), __dict__ (user-defined methods and attributes), __doc__ (the docstring for the class), __name__ (the name of class), __methods__ (methods for this class, not including inherited methods or user-defined methods), and __module__ (module that the class is defined in).", // tp_doc
  0,                                     // tp_traverse
  0,                                     // tp_clear
  0,                                     // tp_richcompare
  0,                                     // tp_weaklistoffset
  VTK_PYTHON_UTIL_SUPRESS_UNINITIALIZED
};

int PyVTKClass_Check(PyObject *obj)
{
  return (obj->ob_type == &PyVTKClassType);
}

//--------------------------------------------------------------------
// Concatenate an array of strings into a single string.  The resulting
// string is allocated via new.  The array of strings must be null-terminated,
// e.g. static char *strings[] = {"string1", "string2", NULL};
static PyObject *vtkBuildDocString(char *docstring[])
{
  PyObject *result;
  char *data;
  int i, j, n;
  int *m;
  int total = 0;

  for (n = 0; docstring[n] != NULL; n++)
    {
    ;
    }

  m = new int[n];

  for (i = 0; i < n; i++)
    {
    m[i] = static_cast<int>(strlen(docstring[i]));
    total += m[i];
    }

  result = PyString_FromStringAndSize(docstring[0], m[0]);
  
  if (n > 1)
    {
    _PyString_Resize(&result, total);
    }

  data = PyString_AsString(result);
  
  j = m[0];
  for (i = 1; i < n; i++)
    {
    strcpy(&data[j], docstring[i]);
    j += m[i];
    }
  
  delete [] m;

  return result;
}

PyObject *PyVTKClass_New(vtknewfunc constructor,
                         PyMethodDef *methods,
                         char *classname, char *modulename, char *docstring[],
                         PyObject *base)
{
  static PyObject *modulestr[10] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }; 
  static int nmodulestr = 10;
  PyObject *moduleobj = 0;
  PyObject *self = NULL;
  int i;

  if (vtkPythonHash)
    {
    vtkstd::map<vtkstd::string, PyObject*>::iterator it =
      vtkPythonHash->ClassHash->find(classname);
    if(it != vtkPythonHash->ClassHash->end())
      {
      self = it->second;
      }
    }
  if (self)
    {
    Py_INCREF(self);
    }
  else
    {
#if (PY_MAJOR_VERSION >= 2)
    PyVTKClass *class_self = PyObject_New(PyVTKClass, &PyVTKClassType);
#else
    PyVTKClass *class_self = PyObject_NEW(PyVTKClass, &PyVTKClassType);
#endif  
    self = (PyObject *)class_self;
    
    if (base)
      {
      class_self->vtk_bases = PyTuple_New(1);
      PyTuple_SET_ITEM(class_self->vtk_bases, 0, base);
      }
    else
      {
      class_self->vtk_bases = PyTuple_New(0);
      }
    class_self->vtk_dict = NULL;
    class_self->vtk_name = PyString_FromString(classname);

    class_self->vtk_getattr = NULL;
    class_self->vtk_setattr = NULL;
    class_self->vtk_delattr = NULL;
    
    class_self->vtk_methods = methods;
    class_self->vtk_new = constructor;
    class_self->vtk_doc = vtkBuildDocString(docstring);

    // intern the module string
    for (i = 0; i < nmodulestr; i++)
      {
      if (modulestr[i] == 0)
        {
        modulestr[i] = PyString_InternFromString(modulename);
        moduleobj = modulestr[i];
        Py_INCREF(moduleobj);
        break;
        }
      else if (strcmp(modulename,PyString_AsString(modulestr[i])) == 0)
        {
        moduleobj = modulestr[i];
        Py_INCREF(moduleobj);
        break;
        }
      }
    if (i == nmodulestr)
      {
      moduleobj = PyString_FromString(modulename);
      }

    class_self->vtk_module = moduleobj;

    vtkPythonAddClassToHash(self,classname);
    }

  return (PyObject *)self;
}

//--------------------------------------------------------------------
static PyObject *PyVTKClass_NewSubclass(PyObject *, PyObject *args,
                                        PyObject *kw)
{
  static const char *kwlist[] = {"name", "bases", "dict", NULL};

  PyVTKClass *newclass;
  char *classname;
  PyObject *globals;
  PyObject *bases;
  PyVTKClass *base;
  PyObject *attributes;

  if ((PyArg_ParseTupleAndKeywords(args, kw, (char*)"sOO", (char**)kwlist, 
                                   &classname, &bases, &attributes)))
    {
    if (!PyTuple_Check(bases) || PyTuple_Size(bases) != 1)
      {
      PyErr_SetString(PyExc_ValueError,
                      "multiple inheritence is not allowed with VTK classes");
      return NULL;
      }

    base = (PyVTKClass *)PyTuple_GetItem(bases,0);
    if (base == 0)
      {
      PyErr_SetString(PyExc_ValueError,"bases must be a tuple");
      return NULL;
      }

    if (!PyVTKClass_Check((PyObject *)base))
      {
      PyErr_SetString(PyExc_ValueError,"base class is not a VTK class");
      return NULL;
      }

    if (!PyDict_Check(attributes))
      {
      PyErr_SetString(PyExc_ValueError,"namespace not provided");
      return NULL;
      }

    if (PyDict_GetItemString(attributes, (char*)"__del__"))
      {
      PyErr_SetString(PyExc_ValueError, "__del__ attribute is not supported");
      return NULL;
      }

#if (PY_MAJOR_VERSION >= 2)
    newclass = PyObject_New(PyVTKClass, &PyVTKClassType);
#else
    newclass = PyObject_NEW(PyVTKClass, &PyVTKClassType);
#endif  

    Py_INCREF(bases);
    Py_INCREF(attributes);

    newclass->vtk_bases = bases;
    newclass->vtk_dict = attributes;
    newclass->vtk_name = PyString_FromString(classname);

    newclass->vtk_getattr = PyDict_GetItemString(attributes, (char*)"__getattr__");
    if (newclass->vtk_getattr == 0)
      {
      newclass->vtk_getattr = base->vtk_getattr;
      }
    Py_XINCREF(newclass->vtk_getattr);
    newclass->vtk_setattr = PyDict_GetItemString(attributes, (char*)"__setattr__");
    if (newclass->vtk_setattr == 0)
      {
      newclass->vtk_setattr = base->vtk_setattr;
      }
    Py_XINCREF(newclass->vtk_setattr);
    newclass->vtk_delattr = PyDict_GetItemString(attributes, (char*)"__delattr__");
    if (newclass->vtk_delattr == 0)
      {
      newclass->vtk_delattr = base->vtk_delattr;
      }
    Py_XINCREF(newclass->vtk_delattr);

    newclass->vtk_methods = NULL;
    newclass->vtk_new = base->vtk_new;
    newclass->vtk_module = NULL;
    newclass->vtk_doc = NULL;

    globals = PyEval_GetGlobals();
    if (globals != NULL)
      {
      PyObject *modname = PyDict_GetItemString(globals, (char*)"__name__");
      if (modname != NULL)
        {
        Py_INCREF(modname);
        newclass->vtk_module = modname;
        }
      }
    if (newclass->vtk_module == NULL)
      {
      newclass->vtk_module = PyString_FromString("__main__");
      }

    newclass->vtk_doc = PyDict_GetItemString(attributes, (char*)"__doc__");
    if (newclass->vtk_doc)
      {
      Py_INCREF(newclass->vtk_doc);
      PyDict_DelItemString(attributes, (char*)"__doc__");
      }
    else
      {
      newclass->vtk_doc = PyString_FromString("");
      }

    return (PyObject *)newclass;    
    }
  return NULL;
}

//--------------------------------------------------------------------
static PyObject *PyVTKSpecialObject_PyString(PyVTKSpecialObject *self)
{
  vtksys_ios::ostringstream os;
  self->vtk_info->print_func(os, self->vtk_ptr);
  const vtksys_stl::string &s = os.str();
  return PyString_FromStringAndSize(s.data(), s.size());
}

//--------------------------------------------------------------------
static PyObject *PyVTKSpecialObject_PyRepr(PyVTKSpecialObject *self)
{
  char buf[255];
  sprintf(buf,"<%s %s at %p>", self->ob_type->tp_name, 
          PyString_AsString(self->vtk_info->classname), self);
  return PyString_FromString(buf);
}

//--------------------------------------------------------------------
static PyObject *PyVTKSpecialObject_PyGetAttr(PyVTKSpecialObject *self,
                                              PyObject *attr)
{
  char *name = PyString_AsString(attr);
  PyMethodDef *meth;

  if (name[0] == '_')
    {
    if (strcmp(name,"__name__") == 0)
      {
      Py_INCREF(self->vtk_info->classname);
      return self->vtk_info->classname;