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
|
#include <stdlib.h>
#include <string.h>
#include <plibsys.h>
#include "channel.h"
void channel_init(struct channel_t *chan)
{
chan->active = false;
chan->paused = false;
chan->volume = 255;
chan->pan = 0;
chan->sound_mutex = p_mutex_new();
chan->sound.left = NULL;
chan->sound.right = NULL;
chan->pos = 0;
}
void channel_reset(struct channel_t *chan)
{
p_atomic_int_set(&(chan->paused), false);
p_atomic_int_set(&(chan->volume), 255);
p_atomic_int_set(&(chan->pan), 0);
chan->pos = 0;
p_atomic_int_set(&(chan->active), false);
}
void channel_pause(struct channel_t *chan)
{
p_atomic_int_set(&(chan->paused), true);
}
void channel_resume(struct channel_t *chan)
{
p_atomic_int_set(&(chan->paused), false);
}
void channel_set_volume(struct channel_t *chan, float volume)
{
if (volume > 1.0f) volume = 1.0f;
if (volume < 0.0f) volume = 0.0f;
p_atomic_int_set(&(chan->volume), 255*volume);
}
void channel_set_pan(struct channel_t *chan, float pan)
{
if (pan > 1.0f) pan = 1.0f;
if (pan < -1.0f) pan = -1.0f;
p_atomic_int_set(&(chan->pan), 128*pan);
}
void channel_get_next_sample(float *left, float *right, struct channel_t *chan)
{
bool active = p_atomic_int_get(&(chan->active));
bool paused = p_atomic_int_get(&(chan->paused));
if (!active || paused) {
/* skip this channel */
*left = 0;
*right = 0;
return;
}
if (!p_mutex_trylock(chan->sound_mutex)) {
/* can't lock mutex, skip */
*left = 0;
*right = 0;
return;
}
*left = chan->sound.left[chan->pos];
*right = chan->sound.right[chan->pos];
chan->pos += 1;
if (chan->pos >= chan->sound.len) {
channel_reset(chan);
}
p_mutex_unlock(chan->sound_mutex);
}
|
