engines/gig/Filter.h

/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003 by Benno Senoner and Christian Schoenebeck         *
 *                                                                         *
 *   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                                                   *
 ***************************************************************************/

#ifndef __LS_GIG_FILTER_H__
#define __LS_GIG_FILTER_H__

#include "../../common/global.h"

#if DEBUG_HEADERS
# warning Filter.h included
#endif // DEBUG_HEADERS

#include "../common/BiquadFilter.h"

// TODO: Gigasampler's "Turbo Lowpass" and "Bandreject" filters not implemented yet

#include "../../lib/fileloader/libgig/gig.h"

#define LSF_BW 0.9
#define LSF_FB 0.9f

namespace LinuxSampler { namespace gig {

    /**
     * This is a filter similar to the ones from Gigasampler.
     */
    class Filter {
        protected:
            BandpassFilter    BasicBPFilter;
            HighpassFilter    HPFilter;
            BandpassFilter    BPFilter;
            LowpassFilter     LPFilter;
            BiquadFilter*     pFilter;
            bq_t              scale;
            bq_t              resonance;
            bq_t              cutoff;
            ::gig::vcf_type_t Type;
        public:
            bool Enabled;

            inline Filter() {
                // set filter type to 'lowpass' by default
                pFilter = &LPFilter;
                Type    = ::gig::vcf_type_lowpass;
            }

            inline bq_t Cutoff()     { return cutoff; }

            inline bq_t Resonance()  { return resonance; }

            inline void SetType(::gig::vcf_type_t FilterType) {
                switch (FilterType) {
                    case ::gig::vcf_type_highpass:
                        pFilter = &HPFilter;
                        break;
                    case ::gig::vcf_type_bandreject: //TODO: not implemented yet
                        Type = ::gig::vcf_type_bandpass;
                    case ::gig::vcf_type_bandpass:
                        pFilter = &BPFilter;
                        break;
                    case ::gig::vcf_type_lowpassturbo: //TODO: not implemented yet
                    default:
                        Type = ::gig::vcf_type_lowpass;
                    case ::gig::vcf_type_lowpass:
                        pFilter = &LPFilter;

                }
                Type = FilterType;
            }

            inline void SetParameters(bq_t cutoff, bq_t resonance, bq_t fs) {
                BasicBPFilter.SetParameters(cutoff, 0.7, fs);
                switch (Type) {
                    case ::gig::vcf_type_highpass:
                        HPFilter.SetParameters(cutoff, 1.0 - resonance * LSF_BW, fs);
                        break;
                    case ::gig::vcf_type_bandpass:
                        BPFilter.SetParameters(cutoff, 1.0 - resonance * LSF_BW, fs);
                        break;
                    case ::gig::vcf_type_lowpass:
                        LPFilter.SetParameters(cutoff, 1.0 - resonance * LSF_BW, fs);
                        break;
                }
                this->scale     = 1.0f - resonance * 0.7f;
                this->resonance = resonance;
                this->cutoff    = cutoff;
            }

            inline bq_t Apply(const bq_t in) {
                return (Enabled) ? pFilter->Apply(in) * this->scale +
                                  BasicBPFilter.ApplyFB(in, this->resonance * LSF_FB) * this->resonance
                                : in;
            }
    };

}} //namespace LinuxSampler::gig

#endif // __LS_GIG_FILTER_H__
1	/***************************************************************************
2	* *
3	* LinuxSampler - modular, streaming capable sampler *
4	* *
5	* Copyright (C) 2003 by Benno Senoner and Christian Schoenebeck *
6	* *
7	* This program is free software; you can redistribute it and/or modify *
8	* it under the terms of the GNU General Public License as published by *
9	* the Free Software Foundation; either version 2 of the License, or *
10	* (at your option) any later version. *
11	* *
12	* This program is distributed in the hope that it will be useful, *
13	* but WITHOUT ANY WARRANTY; without even the implied warranty of *
14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
15	* GNU General Public License for more details. *
16	* *
17	* You should have received a copy of the GNU General Public License *
18	* along with this program; if not, write to the Free Software *
19	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, *
20	* MA 02111-1307 USA *
21	***************************************************************************/
22
23	#ifndef __LS_GIG_FILTER_H__
24	#define __LS_GIG_FILTER_H__
25
26	#include "../../common/global.h"
27
28	#if DEBUG_HEADERS
29	# warning Filter.h included
30	#endif // DEBUG_HEADERS
31
32	#include "../common/BiquadFilter.h"
33
34	// TODO: Gigasampler's "Turbo Lowpass" and "Bandreject" filters not implemented yet
35
36	#include "../../lib/fileloader/libgig/gig.h"
37
38	#define LSF_BW 0.9
39	#define LSF_FB 0.9f
40
41	namespace LinuxSampler { namespace gig {
42
43	/**
44	* This is a filter similar to the ones from Gigasampler.
45	*/
46	class Filter {
47	protected:
48	BandpassFilter BasicBPFilter;
49	HighpassFilter HPFilter;
50	BandpassFilter BPFilter;
51	LowpassFilter LPFilter;
52	BiquadFilter* pFilter;
53	bq_t scale;
54	bq_t resonance;
55	bq_t cutoff;
56	::gig::vcf_type_t Type;
57	public:
58	bool Enabled;
59
60	inline Filter() {
61	// set filter type to 'lowpass' by default
62	pFilter = &LPFilter;
63	Type = ::gig::vcf_type_lowpass;
64	}
65
66	inline bq_t Cutoff() { return cutoff; }
67
68	inline bq_t Resonance() { return resonance; }
69
70	inline void SetType(::gig::vcf_type_t FilterType) {
71	switch (FilterType) {
72	case ::gig::vcf_type_highpass:
73	pFilter = &HPFilter;
74	break;
75	case ::gig::vcf_type_bandreject: //TODO: not implemented yet
76	Type = ::gig::vcf_type_bandpass;
77	case ::gig::vcf_type_bandpass:
78	pFilter = &BPFilter;
79	break;
80	case ::gig::vcf_type_lowpassturbo: //TODO: not implemented yet
81	default:
82	Type = ::gig::vcf_type_lowpass;
83	case ::gig::vcf_type_lowpass:
84	pFilter = &LPFilter;
85
86	}
87	Type = FilterType;
88	}
89
90	inline void SetParameters(bq_t cutoff, bq_t resonance, bq_t fs) {
91	BasicBPFilter.SetParameters(cutoff, 0.7, fs);
92	switch (Type) {
93	case ::gig::vcf_type_highpass:
94	HPFilter.SetParameters(cutoff, 1.0 - resonance * LSF_BW, fs);
95	break;
96	case ::gig::vcf_type_bandpass:
97	BPFilter.SetParameters(cutoff, 1.0 - resonance * LSF_BW, fs);
98	break;
99	case ::gig::vcf_type_lowpass:
100	LPFilter.SetParameters(cutoff, 1.0 - resonance * LSF_BW, fs);
101	break;
102	}
103	this->scale = 1.0f - resonance * 0.7f;
104	this->resonance = resonance;
105	this->cutoff = cutoff;
106	}
107
108	inline bq_t Apply(const bq_t in) {
109	return (Enabled) ? pFilter->Apply(in) * this->scale +
110	BasicBPFilter.ApplyFB(in, this->resonance * LSF_FB) * this->resonance
111	: in;
112	}
113	};
114
115	}} //namespace LinuxSampler::gig
116
117	#endif // __LS_GIG_FILTER_H__