c@351: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
c@351: 
c@351: /*
c@351:     QM DSP library
c@351:     Centre for Digital Music, Queen Mary, University of London.
c@351:  
c@351:     This program is free software; you can redistribute it and/or
c@351:     modify it under the terms of the GNU General Public License as
c@351:     published by the Free Software Foundation; either version 2 of the
c@351:     License, or (at your option) any later version.  See the file
c@351:     COPYING included with this distribution for more information.
c@351: */
c@351: 
c@351: #include "SincWindow.h"
c@351: 
c@351: #include <cmath>
c@351: 
c@351: void
c@351: SincWindow::init()
c@351: {
c@351:     if (m_length < 1) {
cannam@483:         return;
c@351:     } else if (m_length < 2) {
cannam@483:         m_window.push_back(1);
cannam@483:         return;
c@351:     } else {
c@351: 
cannam@483:         int n0 = (m_length % 2 == 0 ? m_length/2 : (m_length - 1)/2);
cannam@483:         int n1 = (m_length % 2 == 0 ? m_length/2 : (m_length + 1)/2);
cannam@483:         double m = 2 * M_PI / m_p;
c@351: 
cannam@483:         for (int i = 0; i < n0; ++i) {
cannam@483:             double x = ((m_length / 2) - i) * m;
cannam@483:             m_window.push_back(sin(x) / x);
cannam@483:         }
c@351: 
cannam@483:         m_window.push_back(1.0);
c@351: 
cannam@483:         for (int i = 1; i < n1; ++i) {
cannam@483:             double x = i * m;
cannam@483:             m_window.push_back(sin(x) / x);
cannam@483:         }
c@351:     }
c@351: }
c@351: