ur_kin_py.cpp

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/*********************************************************************
 *
 * Python wrapper for UR kinematics
 * Author: Kelsey Hawkins (kphawkins@gatech.edu)
 *
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2013, Georgia Institute of Technology
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#include <boost/numpy.hpp>
#include <boost/scoped_array.hpp>

#include <ur_kinematics/ur_kin.h>

namespace p = boost::python;
namespace np = boost::numpy;

np::ndarray forward_wrapper(np::ndarray const & q_arr) {
  if(q_arr.get_dtype() != np::dtype::get_builtin<double>()) {
    PyErr_SetString(PyExc_TypeError, "Incorrect array data type");
    p::throw_error_already_set();
  }
  if(q_arr.get_nd() != 1) {
    PyErr_SetString(PyExc_TypeError, "Incorrect number of dimensions");
    p::throw_error_already_set();
  }
  if(q_arr.shape(0) != 6) {
    PyErr_SetString(PyExc_TypeError, "Incorrect shape (should be 6)");
    p::throw_error_already_set();
  }
  Py_intptr_t shape[2] = { 4, 4 };
  np::ndarray result = np::zeros(2,shape,np::dtype::get_builtin<double>()); 
  ur_kinematics::forward(reinterpret_cast<double*>(q_arr.get_data()), 
                         reinterpret_cast<double*>(result.get_data()));
  return result;
}

np::ndarray inverse_wrapper(np::ndarray const & array, PyObject * q6_des_py) {
  if(array.get_dtype() != np::dtype::get_builtin<double>()) {
    PyErr_SetString(PyExc_TypeError, "Incorrect array data type");
    p::throw_error_already_set();
  }
  if(array.get_nd() != 2) {
    PyErr_SetString(PyExc_TypeError, "Incorrect number of dimensions");
    p::throw_error_already_set();
  }
  if(array.shape(0) != 4 || array.shape(1) != 4) {
    PyErr_SetString(PyExc_TypeError, "Incorrect shape (should be 4x4)");
    p::throw_error_already_set();
  }
  double* T = reinterpret_cast<double*>(array.get_data());
  double* q_sols = (double*) malloc(8*6*sizeof(double));
  double q6_des = PyFloat_AsDouble(q6_des_py);
  int num_sols = ur_kinematics::inverse(T, q_sols, q6_des);
  q_sols = (double*) realloc(q_sols, num_sols*6*sizeof(double));
  return np::from_data(q_sols, np::dtype::get_builtin<double>() , p::make_tuple(num_sols, 6), p::make_tuple(6*sizeof(double), sizeof(double)), p::object());
}

BOOST_PYTHON_MODULE(ur_kin_py) {
  np::initialize();  // have to put this in any module that uses Boost.NumPy
  p::def("forward", forward_wrapper);
  p::def("inverse", inverse_wrapper);
}