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
133
|
/*
* Copyright (C) 2005-2006 Taybin Rutkin <taybin@taybin.com>
* Copyright (C) 2007-2013 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2009 David Robillard <d@drobilla.net>
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef __ardour_logcurve_h__
#define __ardour_logcurve_h__
#include "pbd/fastlog.h"
#include <glibmm/threads.h>
namespace ARDOUR {
class LIBARDOUR_API LogCurve {
public:
LogCurve (float steepness = 0.2, uint32_t len = 0) {
l = len;
S = steepness;
a = log(S);
b = 1.0f / log(1.0f + (1.0f / S));
}
bool operator== (const LogCurve& other) const {
return S == other.S && l == other.l;
}
bool operator!= (const LogCurve& other) const {
return S != other.S || l != other.l;
}
float value (float frac) const {
return (fast_log(frac + S) - a) * b;
}
float value (uint32_t pos) const {
return (fast_log(((float) pos/l) + S) - a) * b;
}
float invert_value (float frac) const {
return (a - fast_log(frac + S)) * b;
}
float invert_value (uint32_t pos) const {
return (a - fast_log(((float) pos/l) + S)) * b;
}
void fill (float *vec, uint32_t veclen, bool invert) const {
float dx = 1.0f/veclen;
float x;
uint32_t i;
if (!invert) {
vec[0] = 0.0;
vec[veclen-1] = 1.0;
for (i = 1, x = 0; i < veclen - 1; x += dx, i++) {
vec[i] = value (x);
}
} else {
vec[0] = 1.0;
vec[veclen-1] = 0.0;
for (i = veclen-2, x = 0.0f; i > 0; x += dx, i--) {
vec[i] = value (x);
}
}
}
float steepness() const { return S; }
uint32_t length() const { return l; }
void set_steepness (float steepness) {
S = steepness;
a = log(S);
b = 1.0f / log(1.0f + (1.0f / S));
}
void set_length (uint32_t len) { l = len; }
mutable Glib::Threads::Mutex lock;
protected:
float a;
float b;
float S;
uint32_t l;
};
class LIBARDOUR_API LogCurveIn : public LogCurve
{
public:
LogCurveIn (float steepness = 0.2, uint32_t len = 0)
: LogCurve (steepness, len) {}
float value (float frac) const {
return (fast_log(frac + S) - a) * b;
}
float value (uint32_t pos) const {
return (fast_log(((float) pos/l) + S) - a) * b;
}
};
class LIBARDOUR_API LogCurveOut : public LogCurve
{
public:
LogCurveOut (float steepness = 0.2, uint32_t len = 0)
: LogCurve (steepness, len) {}
};
} // namespace ARDOUR
#endif /* __ardour_logcurve_h__ */
|
