panda3d/panda/src/pgraph/nodePathCollection_ext.cxx

/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file nodePathCollection_ext.cxx
 * @author rdb
 * @date 2013-12-09
 */

#include "nodePathCollection_ext.h"

#ifdef HAVE_PYTHON

#ifndef CPPPARSER
extern struct Dtool_PyTypedObject Dtool_NodePath;
#ifdef STDFLOAT_DOUBLE
extern struct Dtool_PyTypedObject Dtool_LPoint3d;
#else
extern struct Dtool_PyTypedObject Dtool_LPoint3f;
#endif
#endif

/**
 * This special constructor accepts a Python list of NodePaths.  Since this
 * constructor accepts a generic PyObject *, it should be the last constructor
 * listed in the class record.
 */
void Extension<NodePathCollection>::
__init__(PyObject *self, PyObject *sequence) {
  PyObject *fast = PySequence_Fast(sequence, "NodePathCollection constructor requires a sequence");
  if (fast == nullptr) {
    return;
  }

  Py_ssize_t size = PySequence_Fast_GET_SIZE(fast);
  _this->reserve(size);

  for (int i = 0; i < size; ++i) {
    PyObject *item = PySequence_Fast_GET_ITEM(fast, i);
    if (item == nullptr) {
      return;
    }

    NodePath *path;
    if (!DtoolInstance_GetPointer(item, path, Dtool_NodePath)) {
      // Unable to add item--probably it wasn't of the appropriate type.
      std::ostringstream stream;
      stream << "Element " << i << " in sequence passed to NodePathCollection constructor is not a NodePath";
      std::string str = stream.str();
      PyErr_SetString(PyExc_TypeError, str.c_str());
      Py_DECREF(fast);
      return;
    } else {
      _this->add_path(*path);
    }
  }

  Py_DECREF(fast);
}

/**
 * This special Python method is implement to provide support for the pickle
 * module.
 */
PyObject *Extension<NodePathCollection>::
__reduce__(PyObject *self) const {
  // Here we will return a 4-tuple: (Class, (args), None, iterator), where
  // iterator is an iterator that will yield successive NodePaths.

  // We should return at least a 2-tuple, (Class, (args)): the necessary class
  // object whose constructor we should call (e.g.  this), and the arguments
  // necessary to reconstruct this object.

  PyObject *this_class = (PyObject *)self->ob_type;
  if (this_class == nullptr) {
    return nullptr;
  }

  PyObject *self_iter = PyObject_GetIter(self);
  if (self_iter == nullptr) {
    return nullptr;
  }

  // Since a NodePathCollection is itself an iterator, we can simply pass it
  // as the fourth tuple component.
  return Py_BuildValue("(O()ON)", this_class, Py_None, self_iter);
}

/**
 * Returns the tight bounds as a 2-tuple of LPoint3 objects.  This is a
 * convenience function for Python users, among which the use of
 * calc_tight_bounds may be confusing.  Returns None if calc_tight_bounds
 * returned false.
 */
PyObject *Extension<NodePathCollection>::
get_tight_bounds() const {
  LPoint3 *min_point = new LPoint3;
  LPoint3 *max_point = new LPoint3;

  if (_this->calc_tight_bounds(*min_point, *max_point)) {
#ifdef STDFLOAT_DOUBLE
    PyObject *min_inst = DTool_CreatePyInstance((void*) min_point, Dtool_LPoint3d, true, false);
    PyObject *max_inst = DTool_CreatePyInstance((void*) max_point, Dtool_LPoint3d, true, false);
#else
    PyObject *min_inst = DTool_CreatePyInstance((void*) min_point, Dtool_LPoint3f, true, false);
    PyObject *max_inst = DTool_CreatePyInstance((void*) max_point, Dtool_LPoint3f, true, false);
#endif
    return Py_BuildValue("NN", min_inst, max_inst);
  }
  else {
    return Py_NewRef(Py_None);
  }
}

#endif  // HAVE_PYTHON