libsidplayfp  2.12.0
ExternalFilter.h
1 /*
2  * This file is part of libsidplayfp, a SID player engine.
3  *
4  * Copyright 2011-2020 Leandro Nini <drfiemost@users.sourceforge.net>
5  * Copyright 2007-2010 Antti Lankila
6  * Copyright 2004 Dag Lem <resid@nimrod.no>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2 of the License, or
11  * (at your option) any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21  */
22 
23 #ifndef EXTERNALFILTER_H
24 #define EXTERNALFILTER_H
25 
26 #include "siddefs-fp.h"
27 
28 namespace reSIDfp
29 {
30 
66 {
67 private:
69  int Vlp;
70 
72  int Vhp;
73 
74  int w0lp_1_s7 = 0;
75 
76  int w0hp_1_s17 = 0;
77 
78 public:
84  int clock(int input);
85 
90 
96  void setClockFrequency(double frequency);
97 
101  void reset();
102 };
103 
104 } // namespace reSIDfp
105 
106 #if RESID_INLINING || defined(EXTERNALFILTER_CPP)
107 
108 namespace reSIDfp
109 {
110 
111 RESID_INLINE
112 int ExternalFilter::clock(int input)
113 {
114  const int Vi = (input<<11) - (1 << (11+15));
115  const int dVlp = (w0lp_1_s7 * (Vi - Vlp) >> 7);
116  const int dVhp = (w0hp_1_s17 * (Vlp - Vhp) >> 17);
117  Vlp += dVlp;
118  Vhp += dVhp;
119  return (Vlp - Vhp) >> 11;
120 }
121 
122 } // namespace reSIDfp
123 
124 #endif
125 
126 #endif
Definition: ExternalFilter.h:66
int clock(int input)
Definition: ExternalFilter.h:112
void reset()
Definition: ExternalFilter.cpp:59
void setClockFrequency(double frequency)
Definition: ExternalFilter.cpp:46
ExternalFilter()
Definition: ExternalFilter.cpp:41