1 /*
2 * This file is part of libsidplayfp, a SID player engine.
3 *
4 * Copyright 2011-2013 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 #include "Filter.h"
24
25 namespace reSIDfp
26 {
27
enable(bool enable)28 void Filter::enable(bool enable)
29 {
30 enabled = enable;
31
32 if (enabled)
33 {
34 writeRES_FILT(filt);
35 }
36 else
37 {
38 filt1 = filt2 = filt3 = filtE = false;
39 }
40 }
41
reset()42 void Filter::reset()
43 {
44 writeFC_LO(0);
45 writeFC_HI(0);
46 writeMODE_VOL(0);
47 writeRES_FILT(0);
48 }
49
writeFC_LO(unsigned char fc_lo)50 void Filter::writeFC_LO(unsigned char fc_lo)
51 {
52 fc = (fc & 0x7f8) | (fc_lo & 0x007);
53 updatedCenterFrequency();
54 }
55
writeFC_HI(unsigned char fc_hi)56 void Filter::writeFC_HI(unsigned char fc_hi)
57 {
58 fc = (fc_hi << 3 & 0x7f8) | (fc & 0x007);
59 updatedCenterFrequency();
60 }
61
writeRES_FILT(unsigned char res_filt)62 void Filter::writeRES_FILT(unsigned char res_filt)
63 {
64 filt = res_filt;
65
66 updateResonance((res_filt >> 4) & 0x0f);
67
68 if (enabled)
69 {
70 filt1 = (filt & 0x01) != 0;
71 filt2 = (filt & 0x02) != 0;
72 filt3 = (filt & 0x04) != 0;
73 filtE = (filt & 0x08) != 0;
74 }
75
76 updatedMixing();
77 }
78
writeMODE_VOL(unsigned char mode_vol)79 void Filter::writeMODE_VOL(unsigned char mode_vol)
80 {
81 vol = mode_vol & 0x0f;
82 lp = (mode_vol & 0x10) != 0;
83 bp = (mode_vol & 0x20) != 0;
84 hp = (mode_vol & 0x40) != 0;
85 voice3off = (mode_vol & 0x80) != 0;
86
87 updatedMixing();
88 }
89
90 } // namespace reSIDfp
91