Chris@366: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@366: /*
Chris@366:     Constant-Q library
Chris@366:     Copyright (c) 2013-2014 Queen Mary, University of London
Chris@366: 
Chris@366:     Permission is hereby granted, free of charge, to any person
Chris@366:     obtaining a copy of this software and associated documentation
Chris@366:     files (the "Software"), to deal in the Software without
Chris@366:     restriction, including without limitation the rights to use, copy,
Chris@366:     modify, merge, publish, distribute, sublicense, and/or sell copies
Chris@366:     of the Software, and to permit persons to whom the Software is
Chris@366:     furnished to do so, subject to the following conditions:
Chris@366: 
Chris@366:     The above copyright notice and this permission notice shall be
Chris@366:     included in all copies or substantial portions of the Software.
Chris@366: 
Chris@366:     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
Chris@366:     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
Chris@366:     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
Chris@366:     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
Chris@366:     CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
Chris@366:     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
Chris@366:     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Chris@366: 
Chris@366:     Except as contained in this notice, the names of the Centre for
Chris@366:     Digital Music; Queen Mary, University of London; and Chris Cannam
Chris@366:     shall not be used in advertising or otherwise to promote the sale,
Chris@366:     use or other dealings in this Software without prior written
Chris@366:     authorization.
Chris@366: */
Chris@366: 
Chris@366: #include "SincWindow.h"
Chris@366: 
Chris@366: #include <cmath>
Chris@366: 
Chris@366: void
Chris@366: SincWindow::init()
Chris@366: {
Chris@366:     if (m_length < 1) {
Chris@366: 	return;
Chris@366:     } else if (m_length < 2) {
Chris@366: 	m_window.push_back(1);
Chris@366: 	return;
Chris@366:     } else {
Chris@366: 
Chris@366: 	int n0 = (m_length % 2 == 0 ? m_length/2 : (m_length - 1)/2);
Chris@366: 	int n1 = (m_length % 2 == 0 ? m_length/2 : (m_length + 1)/2);
Chris@366: 	double m = 2 * M_PI / m_p;
Chris@366: 
Chris@366: 	for (int i = 0; i < n0; ++i) {
Chris@366: 	    double x = ((m_length / 2) - i) * m;
Chris@366: 	    m_window.push_back(sin(x) / x);
Chris@366: 	}
Chris@366: 
Chris@366: 	m_window.push_back(1.0);
Chris@366: 
Chris@366: 	for (int i = 1; i < n1; ++i) {
Chris@366: 	    double x = i * m;
Chris@366: 	    m_window.push_back(sin(x) / x);
Chris@366: 	}
Chris@366:     }
Chris@366: }
Chris@366: