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
|
#include <assert.h>
#include "sig.h"
typedef struct ops_lerp_ctxt_t {
sig_t *a, *b, *t;
} ops_lerp_ctxt_t;
static size_t ops_lerp_size(va_list ap)
{
return sizeof(ops_lerp_ctxt_t);
}
/* Supply two sig_t's to be interpolated and another for the t, this sig_t
* takes ownership of them so they'll be freed on destroy when the ops_lerp
* sig_t is freed.
*/
static void ops_lerp_init(void *context, va_list ap)
{
ops_lerp_ctxt_t *ctxt = context;
assert(ctxt);
ctxt->a = va_arg(ap, sig_t *);
ctxt->b = va_arg(ap, sig_t *);
ctxt->t = va_arg(ap, sig_t *);
}
static void ops_lerp_destroy(void *context)
{
ops_lerp_ctxt_t *ctxt = context;
assert(ctxt);
sig_free(ctxt->a);
sig_free(ctxt->b);
sig_free(ctxt->t);
}
static inline float lerp(float a, float b, float t)
{
return (1.f - t) * a + b * t;
}
static float ops_lerp_output(void *context, unsigned ticks_ms)
{
ops_lerp_ctxt_t *ctxt = context;
assert(ctxt);
return lerp(sig_output(ctxt->a, ticks_ms),
sig_output(ctxt->b, ticks_ms),
sig_output(ctxt->t, ticks_ms));
}
sig_ops_t sig_ops_lerp = {
.size = ops_lerp_size,
.init = ops_lerp_init,
.destroy = ops_lerp_destroy,
.output = ops_lerp_output,
};
|
