c@119: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
c@119: /*
c@119:     Constant-Q library
c@119:     Copyright (c) 2013-2014 Queen Mary, University of London
c@119: 
c@119:     Permission is hereby granted, free of charge, to any person
c@119:     obtaining a copy of this software and associated documentation
c@119:     files (the "Software"), to deal in the Software without
c@119:     restriction, including without limitation the rights to use, copy,
c@119:     modify, merge, publish, distribute, sublicense, and/or sell copies
c@119:     of the Software, and to permit persons to whom the Software is
c@119:     furnished to do so, subject to the following conditions:
c@119: 
c@119:     The above copyright notice and this permission notice shall be
c@119:     included in all copies or substantial portions of the Software.
c@119: 
c@119:     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
c@119:     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
c@119:     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
c@119:     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
c@119:     CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
c@119:     CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
c@119:     WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
c@119: 
c@119:     Except as contained in this notice, the names of the Centre for
c@119:     Digital Music; Queen Mary, University of London; and Chris Cannam
c@119:     shall not be used in advertising or otherwise to promote the sale,
c@119:     use or other dealings in this Software without prior written
c@119:     authorization.
c@119: */
c@119: 
c@119: #include "SincWindow.h"
c@119: 
c@119: #include <cmath>
c@119: 
c@119: void
c@119: SincWindow::init()
c@119: {
c@119:     if (m_length < 1) {
c@119: 	return;
c@119:     } else if (m_length < 2) {
c@119: 	m_window.push_back(1);
c@119: 	return;
c@119:     } else {
c@119: 
c@119: 	int n0 = (m_length % 2 == 0 ? m_length/2 : (m_length - 1)/2);
c@119: 	int n1 = (m_length % 2 == 0 ? m_length/2 : (m_length + 1)/2);
c@119: 	double m = 2 * M_PI / m_p;
c@119: 
c@119: 	for (int i = 0; i < n0; ++i) {
c@119: 	    double x = ((m_length / 2) - i) * m;
c@119: 	    m_window.push_back(sin(x) / x);
c@119: 	}
c@119: 
c@119: 	m_window.push_back(1.0);
c@119: 
c@119: 	for (int i = 1; i < n1; ++i) {
c@119: 	    double x = i * m;
c@119: 	    m_window.push_back(sin(x) / x);
c@119: 	}
c@119:     }
c@119: }
c@119: