blob: 837b4a7124b4c6d77a1b8ab518f42c2deb30d881 (
plain)
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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
#include "envelope.h"
Envelope::Envelope(env_settings_t s, int frames)
{
level=0;
t=0;
state=ATTACK;
max=ONE;
nth_frame=frames;
set_ratefactor(1.0);
has_release_phase=(s.release>=0);
if (!has_release_phase)
s.hold=false;
set_attack(s.attack);
set_decay(s.decay);
set_sustain(s.sustain);
set_release(s.release);
set_hold(s.hold);
}
void Envelope::set_ratefactor(double factor)
{
ratefactor=ONE*factor;
set_attack(attack_orig);
set_decay(decay_orig);
set_release(release_orig);
}
void Envelope::set_attack(jack_nframes_t a)
{
attack_orig=a;
attack=(a*ratefactor >>SCALE)/nth_frame;
if (state==ATTACK)
t=attack*level >>SCALE;
}
void Envelope::set_decay(jack_nframes_t d)
{
decay_orig=d;
decay=(d*ratefactor >>SCALE)/nth_frame;
if ((state==DECAY) && (sustain!=ONE))
if (sustain<ONE) //to avoid a div. by zero
t=decay*(ONE-level)/(ONE-sustain);
}
void Envelope::set_sustain(fixed_t s)
{
sustain=s;
sustain_orig=s;
}
void Envelope::set_release(jack_nframes_t r)
{
release_orig=r;
release=(r*ratefactor >>SCALE)/nth_frame;
if (state==RELEASE)
if (sustain>0) //to avoid a div. by zero
t=release*(sustain-level)/sustain;
}
void Envelope::set_hold(bool h)
{
hold=h;
if ((h==false) && (state==HOLD))
{
t=0;
state=RELEASE;
}
}
void Envelope::reattack()
{
state=ATTACK;
t=attack*level >>SCALE;
sustain=sustain_orig;
}
void Envelope::reset()
{
state=ATTACK;
sustain=sustain_orig;
level=0;
t=0;
}
void Envelope::release_key()
{
if (has_release_phase)
if ((state!=RELEASE) && (state!=DONE))
{
t=0;
state=RELEASE;
sustain=level;
}
//if (!has_release_phase) ignore();
}
bool Envelope::still_active()
{
return (state!=DONE);
}
fixed_t Envelope::get_level() //must be called each frame
{
switch (state)
{
case ATTACK:
if (t>=attack)
{
level=max;
state=DECAY;
t=0;
}
else //will only happen, if t < attack. so attack will
{ //always be greater than zero -> no div. by zero
level=max * t / attack ;
}
break;
case DECAY:
if (t>=decay)
{
level=max*sustain >>SCALE;
if (has_release_phase)
if (hold)
state=HOLD;
else
state=RELEASE;
else
state=DONE;
t=0;
}
else //will only happen, if t < decay. so decay will
{ //always be greater than zero -> no div. by zero
level=(ONE - (ONE-sustain)*t/decay)*max >>SCALE;
}
break;
case HOLD:
//does nothing. level must be set properly before entering HOLD state
break;
case RELEASE:
if (t>=release)
{
level=0;
state=DONE;
}
else //will only happen, if t < release. so release will
{ //always be greater than zero -> no div. by zero
level=(sustain - sustain * t/release)*max >>SCALE;
}
break;
case DONE:
//does nothing. level must be set properly before entering DONE state
break;
}
++t;
return level;
}
|
