Chris@126: /* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */
Chris@126: 
Chris@126: /*
Chris@126:     QM DSP library
Chris@126:     Centre for Digital Music, Queen Mary, University of London.
Chris@126:  
Chris@126:     This program is free software; you can redistribute it and/or
Chris@126:     modify it under the terms of the GNU General Public License as
Chris@126:     published by the Free Software Foundation; either version 2 of the
Chris@126:     License, or (at your option) any later version.  See the file
Chris@126:     COPYING included with this distribution for more information.
Chris@126: */
Chris@126: 
Chris@126: #ifndef SINC_WINDOW_H
Chris@126: #define SINC_WINDOW_H
Chris@126: 
Chris@126: #include <vector>
Chris@126: 
Chris@126: class SincWindow
Chris@126: {
Chris@126: public:
Chris@126:     /**
Chris@126:      * Construct a windower of the given length, containing the values
Chris@126:      * of sinc(x) with x=0 in the middle, i.e. at sample (length-1)/2
Chris@126:      * for odd or (length/2)+1 for even length, such that the distance
Chris@126:      * from -pi to pi (the nearest zero crossings either side of the
Chris@126:      * peak) is p samples.
Chris@126:      */
Chris@126:     SincWindow(int length, double p) : m_length(length), m_p(p) { init(); }
Chris@126: 
Chris@126:     int getLength() const {
Chris@126: 	return m_length;
Chris@126:     }
Chris@126: 
Chris@126:     const double *getWindow() const { 
Chris@126: 	return m_window.data();
Chris@126:     }
Chris@126: 
Chris@126:     void cut(double *src) const { 
Chris@126: 	cut(src, src); 
Chris@126:     }
Chris@126: 
Chris@126:     void cut(const double *src, double *dst) const {
Chris@126: 	for (int i = 0; i < m_length; ++i) {
Chris@126: 	    dst[i] = src[i] * m_window[i];
Chris@126: 	}
Chris@126:     }
Chris@126: 
Chris@126: private:
Chris@126:     int m_length;
Chris@126:     double m_p;
Chris@126:     std::vector<double> m_window;
Chris@126: 
Chris@126:     void init();
Chris@126: };
Chris@126: 
Chris@126: #endif