AppPartDesignPy.cpp

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/***************************************************************************
 *   Copyright (c) 2008 Jürgen Riegel (juergen.riegel@web.de)              *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
 *                                                                         *
 *   This library is free software; you can redistribute it and/or         *
 *   modify it under the terms of the GNU Library General Public           *
 *   License as published by the Free Software Foundation; either          *
 *   version 2 of the License, or (at your option) any later version.      *
 *                                                                         *
 *   This library  is distributed in the hope that it will be useful,      *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU Library General Public License for more details.                  *
 *                                                                         *
 *   You should have received a copy of the GNU Library General Public     *
 *   License along with this library; see the file COPYING.LIB. If not,    *
 *   write to the Free Software Foundation, Inc., 59 Temple Place,         *
 *   Suite 330, Boston, MA  02111-1307, USA                                *
 *                                                                         *
 ***************************************************************************/


#include "PreCompiled.h"
#ifndef _PreComp_
# include <Python.h>
#endif

#include <Base/GeometryPyCXX.h>
#include <Base/VectorPy.h>
#include <Base/Tools.h>

static PyObject * makeFilletArc(PyObject *self, PyObject *args)
{
    PyObject *pM1;
    PyObject *pP;
    PyObject *pQ;
    PyObject *pN;
    double r2;
    int ccw;
    if (!PyArg_ParseTuple(args, "O!O!O!O!di",
            &(Base::VectorPy::Type), &pM1,
            &(Base::VectorPy::Type), &pP,
            &(Base::VectorPy::Type), &pQ,
            &(Base::VectorPy::Type), &pN,
            &r2, &ccw))
        return NULL;

    Base::Vector3d M1 = Py::Vector(pM1, false).toVector();
    Base::Vector3d P  = Py::Vector(pP,  false).toVector();
    Base::Vector3d Q  = Py::Vector(pQ,  false).toVector();
    Base::Vector3d N  = Py::Vector(pN,  false).toVector();

    Base::Vector3d u = Q - P;
    Base::Vector3d v = P - M1;
    Base::Vector3d b;
    if (ccw)
        b = u % N;
    else
        b = N % u;
    b.Normalize();

    double uu = u * u;
    double uv = u * v;
    double r1 = v.Length();

    // distinguish between internal and external fillets
    r2 *= Base::sgn(uv);

    double cc = 2.0 * r2 * (b * v - r1);
    double d = uv * uv - uu * cc;
    if (d < 0) {
        PyErr_SetString(PyExc_Exception, "Unable to caluclate intersection points");
        return NULL;
    }

    double t;
    double t1 = (-uv + sqrt(d)) / uu;
    double t2 = (-uv - sqrt(d)) / uu;

    if (fabs(t1) < fabs(t2))
        t = t1;
    else
        t = t2;

    Base::Vector3d M2 = P + (u*t) + (b*r2);
    Base::Vector3d S1 = (r2 * M1 + r1 * M2)/(r1+r2);
    Base::Vector3d S2 = M2 - (b*r2);

    Py::Tuple tuple(3);
    tuple.setItem(0, Py::Vector(S1));
    tuple.setItem(1, Py::Vector(S2));
    tuple.setItem(2, Py::Vector(M2));

    return Py::new_reference_to(tuple);
}

/* registration table  */
struct PyMethodDef PartDesign_methods[] = {
    {"makeFilletArc" ,makeFilletArc,METH_VARARGS,
     "makeFilletArc(...) -- Fillet arc."},
    {NULL, NULL}        /* end of table marker */
};