Phaser.h

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/*
        Phaser.h
        
        Copyright 2002-5 Tim Goetze <tim@quitte.de>
        
        http://quitte.de/dsp/
 
        Standard and fractal-modulated phaser units.
 
*/
/*
        This program is free software; you can redistribute it and/or
        modify it under the terms of the GNU General Public License
        as published by the Free Software Foundation; either version 2
        of the License, or (at your option) any later version.
 
        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.
 
        You should have received a copy of the GNU General Public License
        along with this program; if not, write to the Free Software
        Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
        02111-1307, USA or point your web browser to http://www.gnu.org.
*/
 
#ifndef _PHASER_H_
#define _PHASER_H_
 
#include "dsp/Sine.h"
#include "dsp/Lorenz.h"
#include "dsp/Delay.h"
 
/* all-pass as used by the phaser. */
class PhaserAP
{
        public:
                sample_t a, m;
                
                PhaserAP() 
                { 
                        a = m = 0.; 
                }
 
                void set (double delay)
                {
                        a = (1 - delay) / (1 + delay);
                }
 
                sample_t process (sample_t x)
                {
                        sample_t y = -a * x + m;
                        m = a * y + x;
 
                        return y;
                }
};
 
class PhaserI
: public Plugin
{
        public:
                PhaserAP ap[6];
                DSP::Sine lfo;
 
                sample_t rate;
                sample_t y0;
 
                struct {
                        double bottom, range;
                } delay;
 
                template <sample_func_t>
                        void one_cycle (int frames);
        
                int blocksize, remain;
 
        public:
                static PortInfo port_info [];
 
                void init()
                        {
                                blocksize = 32;
                        }
 
                void activate()
                        {
                                y0 = 0.;
                                remain = 0;
 
                                delay.bottom = 400. / fs;
                                delay.range = 2200. / fs;
 
                                rate = -1; /* force lfo reset in one_cycle() */
                        }
 
                void run (int n)
                        {
                                one_cycle<store_func> (n);
                        }
                
                void run_adding (int n)
                        {
                                one_cycle<adding_func> (n);
                        }
};
 
/* same as above, but filter sweep is controlled by a Lorenz fractal */
 
class PhaserII
: public Plugin
{
        public:
                double fs;
 
                PhaserAP ap[6];
                DSP::Lorenz lorenz;
 
                sample_t rate;
                sample_t y0;
 
                struct {
                        double bottom, range;
                } delay;
 
                template <sample_func_t>
                        void one_cycle (int frames);
        
                int blocksize, remain;
 
        public:
                static PortInfo port_info [];
 
                void init()
                        {
                                blocksize = 32;
                                lorenz.init();
                        }
 
                void activate()
                        {
                                y0 = 0.;
                                remain = 0;
 
                                delay.bottom = 400. / fs;
                                delay.range = 2200. / fs;
 
                                rate = -1; /* force lfo reset in one_cycle() */
                        }
 
                void run (int n)
                        {
                                one_cycle<store_func> (n);
                        }
                
                void run_adding (int n)
                        {
                                one_cycle<adding_func> (n);
                        }
};
 
 
#endif /* _PHASER_H_ */