File: autowah.cc

package info (click to toggle)
wah-plugins 0.1.0-4
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, buster, sid
  • size: 164 kB
  • ctags: 164
  • sloc: cpp: 420; makefile: 32
file content (132 lines) | stat: -rw-r--r-- 3,008 bytes parent folder | download | duplicates (4)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
// -----------------------------------------------------------------------
//
//  Copyright (C) 2009-2014 Fons Adriaensen <fons@linuxaudio.org>
//    
//  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., 675 Mass Ave, Cambridge, MA 02139, USA.
//
// -----------------------------------------------------------------------


#include <math.h>
#include <string.h>
#include "autowah.h"


void Ladspa_Autowah::setport (unsigned long port, LADSPA_Data *data)
{
    _port [port] = data;
}


#define G_RES 4.0f
#define F_MIN 300.0f
#define F_RAT 10
#define B_MIN 0.03f
#define B_RAT 4
#define T_MIN 0.05f 
#define T_LOG 2


void Ladspa_Autowah::active (bool act)
{
    if (! act) return;

    _wbase = F_MIN * 6.28f / _fsam;
    _bbase = B_MIN;
    _rfact = 64.0f / (_fsam * T_MIN);
    _z1 = _z2 = 0;
    _s1 = _s2 = 0;
    _gx = _gy = 0;
    _dr = 0;
}


void Ladspa_Autowah::runproc (unsigned long len, bool add)
{
    int   i, k;
    float *inp = _port [A_INP];
    float *out = _port [A_OUT];
    float z1, z2, s1, s2, gx, gy;
    float ds1, ds2, dgx, dgy;
    float gd, rf, md, fr, dr;
    float b, p, t, w, x, y;

    gx = _gx;
    gy = _gy;
    t = _port [C_OPMIX][0];
    _gy = G_RES * t;
    _gx = _gy + 1 - t;
    dgx = (_gx - gx) / len;
    dgy = (_gy - gy) / len;

    gd = 10 * powf (10.0f, 0.05f * _port [C_DRIVE][0]);
    rf = 1.0f - _rfact / powf (10.0f, T_LOG * _port [C_DECAY][0]);
    md = _port [C_RANGE][0];
    fr = _port [C_FREQ][0];

    z1 = _z1;
    z2 = _z2;
    s1 = _s1;
    s2 = _s2;
    dr = _dr;

    while (len)
    {
	k = (len > 80) ? 64 : len;

	p = 0;
	for (i = 0; i < k; i++)
	{
	    x = inp [i];
	    p += x * x;
	}
	p = gd * sqrtf (p / k);

	if (p > dr) dr += 0.1f * (p - dr);
	if (dr > md) dr = md;
	t = dr + fr; 
	dr = dr * rf + 1e-10f;
	w = _wbase  * (1 + (F_RAT - 1) * t * t); 
	b = w * _bbase * (1 + (B_RAT - 1) * t);
        if (w > 0.7f) w = 0.7f;

	_s1 = -cosf (w);
	_s2 = (1 - b) / (1 + b);
	ds1 = (_s1 - s1) / k;
	ds2 = (_s2 - s2) / k;
  
	for (i = 0; i < k; i++)
	{
	    s1 += ds1;
	    s2 += ds2;
            gx += dgx;
            gy += dgy;
            x = inp [i];
            y = x - s2 * z2;
            out [i] = gx * x - gy * (z2 + s2 * y);                           
            y -= s1 * z1;
            z2 = z1 + s1 * y;
            z1 = y + 1e-10f;
	}
	inp += k;
	out += k;
	len -= k;
    }

    _z1 = z1;
    _z2 = z2;
    _dr = dr;
}