ian@0: //  Copyright 2011, Ian Hobson.
ian@0: //
ian@0: //  This file is part of gpsynth.
ian@0: //
ian@0: //  gpsynth is free software: you can redistribute it and/or modify
ian@0: //  it under the terms of the GNU General Public License as published by
ian@0: //  the Free Software Foundation, either version 3 of the License, or
ian@0: //  (at your option) any later version.
ian@0: //
ian@0: //  gpsynth is distributed in the hope that it will be useful,
ian@0: //  but WITHOUT ANY WARRANTY; without even the implied warranty of
ian@0: //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
ian@0: //  GNU General Public License for more details.
ian@0: //
ian@0: //  You should have received a copy of the GNU General Public License
ian@0: //  along with gpsynth in the file COPYING. 
ian@0: //  If not, see http://www.gnu.org/licenses/.
ian@0: 
ian@0: #pragma once
ian@0: 
ian@0: #include <cmath>
ian@0: #include <iterator>
ian@0: 
ian@0: namespace dsp {
ian@0:   
ian@0: template<typename OutputIterator>
ian@0: void BlackmanWindow(int size, OutputIterator output) {
ian@0:   typedef typename std::iterator_traits<OutputIterator>::value_type T;
ian@0:   T m1 = (M_PI * 2.0) / (size - 1.0);
ian@0:   T m2 = (M_PI * 4.0) / (size - 1.0);
ian@0:   for (T i = 0; i < size; i++) {
ian@0:     *output++ = 0.42 - 0.5 * std::cos(i * m1) + 0.08 * std::cos(i * m2);
ian@0:   }
ian@0: }
ian@0: 
ian@0: template<typename OutputIterator>
ian@0: void HannWindow(int size, OutputIterator output) {
ian@0:   typedef typename std::iterator_traits<OutputIterator>::value_type T;
ian@0:   T m = (M_PI * 2.0) / (size - 1.0);
ian@0:   for (T i = 0; i < size; i++) {
ian@0:     *output++ = 0.5 - 0.5 * std::cos(i * m);
ian@0:   }
ian@0: }
ian@0: 
ian@0: template<typename OutputIterator>
ian@0: void HammingWindow(int size, OutputIterator output) {
ian@0:   typedef typename std::iterator_traits<OutputIterator>::value_type T;
ian@0:   T m = (M_PI * 2.0) / (size - 1.0);
ian@0:   for (T i = 0; i < size; i++) {
ian@0:     *output++ = 0.54 - 0.46 * std::cos(i * m);
ian@0:   }
ian@0: }
ian@0: 
ian@0: };