1 // Copyright 2013 Olivier Gillet.
2 //
3 // Author: Olivier Gillet (ol.gillet@gmail.com)
4 //
5 // Permission is hereby granted, free of charge, to any person obtaining a copy
6 // of this software and associated documentation files (the "Software"), to deal
7 // in the Software without restriction, including without limitation the rights
8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 // copies of the Software, and to permit persons to whom the Software is
10 // furnished to do so, subject to the following conditions:
11 //
12 // The above copyright notice and this permission notice shall be included in
13 // all copies or substantial portions of the Software.
14 //
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 // THE SOFTWARE.
22 //
23 // See http://creativecommons.org/licenses/MIT/ for more information.
24 //
25 // -----------------------------------------------------------------------------
26 //
27 // SVF used for the envelope follower filter bank.
28 
29 #ifndef STREAMS_SVF_H_
30 #define STREAMS_SVF_H_
31 
32 #include "stmlib/stmlib.h"
33 
34 namespace streams {
35 
36 class Svf {
37  public:
Svf()38   Svf() { }
~Svf()39   ~Svf() { }
40 
41   void Init();
42 
set_frequency(int16_t frequency)43   void set_frequency(int16_t frequency) {
44     dirty_ = dirty_ || (frequency_ != frequency);
45     frequency_ = frequency;
46   }
47 
set_resonance(int16_t resonance)48   void set_resonance(int16_t resonance) {
49     resonance_ = resonance;
50     dirty_ = true;
51   }
52 
53   void Process(int32_t sample);
lp()54   inline int32_t lp() const { return lp_; }
bp()55   inline int32_t bp() const { return bp_; }
hp()56   inline int32_t hp() const { return hp_; }
57 
58  private:
59   bool dirty_;
60 
61   int16_t frequency_;
62   int16_t resonance_;
63 
64   int32_t f_;
65   int32_t damp_;
66 
67   int32_t lp_;
68   int32_t bp_;
69   int32_t hp_;
70 
71   DISALLOW_COPY_AND_ASSIGN(Svf);
72 };
73 
74 }  // namespace streams
75 
76 #endif  // STREAMS_SVF_H_
77