-
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathadsr.c
More file actions
122 lines (105 loc) · 3.07 KB
/
adsr.c
File metadata and controls
122 lines (105 loc) · 3.07 KB
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
#include "adsr.h"
void adsr_init(AdsrEnvelope *env, float sample_rate) {
env->sample_rate = sample_rate;
env->phase = ADSR_IDLE;
env->level = 0.0f;
env->time_in_phase = 0.0f;
env->gate = 0;
// Default ADSR parameters
env->attack = 0.1f; // 100ms
env->decay = 0.2f; // 200ms
env->sustain = 0.7f; // 70%
env->release = 0.3f; // 300ms
}
void adsr_set_params(AdsrEnvelope *env, float attack, float decay, float sustain, float release) {
env->attack = attack;
env->decay = decay;
env->sustain = sustain;
env->release = release;
}
void adsr_gate_on(AdsrEnvelope *env) {
env->gate = 1;
env->phase = ADSR_ATTACK;
env->time_in_phase = 0.0f;
// If we were in release, continue from current level
if (env->level == 0.0f) {
env->level = 0.0f;
}
}
void adsr_gate_off(AdsrEnvelope *env) {
env->gate = 0;
if (env->phase != ADSR_IDLE) {
env->phase = ADSR_RELEASE;
env->time_in_phase = 0.0f;
}
}
float adsr_process(AdsrEnvelope *env, int frames) {
float target_level = 0.0f;
float time_increment = 1.0f / env->sample_rate;
switch (env->phase) {
case ADSR_IDLE:
env->level = 0.0f;
break;
case ADSR_ATTACK:
target_level = 1.0f;
env->time_in_phase += time_increment * frames;
if (env->attack <= 0.001f) {
env->level = 1.0f;
env->phase = ADSR_DECAY;
env->time_in_phase = 0.0f;
} else if (env->time_in_phase >= env->attack) {
env->level = 1.0f;
env->phase = ADSR_DECAY;
env->time_in_phase = 0.0f;
} else {
env->level = env->time_in_phase / env->attack;
}
break;
case ADSR_DECAY:
target_level = env->sustain;
env->time_in_phase += time_increment * frames;
if (env->decay <= 0.001f) {
env->level = env->sustain;
env->phase = ADSR_SUSTAIN;
env->time_in_phase = 0.0f;
} else if (env->time_in_phase >= env->decay) {
env->level = env->sustain;
env->phase = ADSR_SUSTAIN;
env->time_in_phase = 0.0f;
} else {
float decay_progress = env->time_in_phase / env->decay;
env->level = 1.0f + (env->sustain - 1.0f) * decay_progress;
}
break;
case ADSR_SUSTAIN:
env->level = env->sustain;
if (!env->gate) {
env->phase = ADSR_RELEASE;
env->time_in_phase = 0.0f;
}
break;
case ADSR_RELEASE:
target_level = 0.0f;
env->time_in_phase += time_increment * frames;
if (env->release <= 0.001f) {
env->level = 0.0f;
env->phase = ADSR_IDLE;
env->time_in_phase = 0.0f;
} else if (env->time_in_phase >= env->release) {
env->level = 0.0f;
env->phase = ADSR_IDLE;
env->time_in_phase = 0.0f;
} else {
float release_progress = env->time_in_phase / env->release;
env->level = env->sustain * (1.0f - release_progress);
}
break;
}
return env->level;
}
void adsr_reset(AdsrEnvelope *env) {
env->phase = ADSR_IDLE;
env->level = 0.0f;
env->time_in_phase = 0.0f;
env->gate = 0;
}