FilterBase.cpp

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/*
-----------------------------------------------------------------------------
This source file is part of VideoTexture library

Copyright (c) 2007 The Zdeno Ash Miklas

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the Free Software
Foundation; either version 2 of the License, or (at your option) any later
version.

This program 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 Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place - Suite 330, Boston, MA 02111-1307, USA, or go to
http://www.gnu.org/copyleft/lesser.txt.
-----------------------------------------------------------------------------
*/

#include "FilterBase.h"

#include <PyObjectPlus.h>
#include <structmember.h>


// FilterBase class implementation

// constructor
FilterBase::FilterBase (void) : m_previous(NULL) {}


// destructor
FilterBase::~FilterBase (void)
{
    // release Python objects, if not released yet
    release();
}


// release python objects
void FilterBase::release (void)
{
    // release previous filter object
    setPrevious(NULL);
}


// set new previous filter
void FilterBase::setPrevious (PyFilter * filt, bool useRefCnt)
{
    // if reference counting has to be used
    if (useRefCnt)
    {
        // reference new filter
        if (filt != NULL) Py_INCREF(filt);
        // release old filter
        Py_XDECREF(m_previous);
    }
    // set new previous filter
    m_previous = filt;
}


// find first filter
FilterBase * FilterBase::findFirst (void)
{
    // find first filter in chain
    FilterBase * frst;
    for (frst = this; frst->m_previous != NULL; frst = frst->m_previous->m_filter) {};
    // set first filter
    return frst;
}



// list offilter types
PyTypeList pyFilterTypes;



// functions for python interface


// object allocation
PyObject * Filter_allocNew (PyTypeObject * type, PyObject * args, PyObject * kwds)
{
    // allocate object
    PyFilter * self = reinterpret_cast<PyFilter*>(type->tp_alloc(type, 0));
    // initialize object structure
    self->m_filter = NULL;
    // return allocated object
    return reinterpret_cast<PyObject*>(self);
}

// object deallocation
void Filter_dealloc (PyFilter * self)
{
    // release object attributes
    if (self->m_filter != NULL)
    {
        self->m_filter->release();
        delete self->m_filter;
        self->m_filter = NULL;
    }
}


// get previous pixel filter object
PyObject * Filter_getPrevious (PyFilter * self, void * closure)
{
    // if filter object is available
    if (self->m_filter != NULL)
    {
        // pixel filter object
        PyObject * filt = reinterpret_cast<PyObject*>(self->m_filter->getPrevious());
        // if filter is present
        if (filt != NULL)
        {
            // return it
            Py_INCREF(filt);
            return filt;
        }
    }
    // otherwise return none
    Py_RETURN_NONE;
}


// set previous pixel filter object
int Filter_setPrevious (PyFilter * self, PyObject * value, void * closure)
{
    // if filter object is available
    if (self->m_filter != NULL)
    {
        // check new value
        if (value == NULL || !pyFilterTypes.in(Py_TYPE(value)))
        {
            // report value error
            PyErr_SetString(PyExc_TypeError, "Invalid type of value");
            return -1;
        }
        // set new value
        self->m_filter->setPrevious(reinterpret_cast<PyFilter*>(value));
    }
    // return success
    return 0;
}