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
|
#ifndef _KNOBS_H
#define _KNOBS_H
#include <assert.h>
/* A knob exposes a binding for some float in a module's context
* which can be varied at runtime between frames to influence
* the output. There's some overlap with settings, but settings
* are more intended for configuration applied at context
* creation, which won't vary frame-to-frame, but may influence
* the initial value and/or automatic behavior of knobs for
* instance, or even which knobs are available.
*
* At this time knobs will only apply to floats, accompanied by
* some rudimentary bounds.
*
* Integer types would probably be useful, and maybe a precision
* specifier, those can be added in the future as needed, but I'd
* like to keep it simple for now and see what kind of problems
* emerge.
*
* The current expectation is that a module context struct will
* incorporate an array of knobs, replacing loose floats already
* being automatically varied within the module frame-to-frame.
*
* The module will then use the knob_auto_* helpers below to
* access and manipulate the values, instead of directly
* accessing the loose floats as before.
*
* External manipulators of the knobs will use the knob_*
* helpers, instead of the knob_auto_* helpers, to
* access+manipulate the knobs. These helpers are basically just
* to get external and internal manipulators to agree on which
* side owns control via the managed field.
*/
typedef struct knob_t {
const char *name; /* Short API-oriented name */
const char *desc; /* Longer UI-oriented name */
const float min, max; /* Value bounds */
float value; /* Value knob affects */
unsigned managed:1; /* Set when knob control of value is active,
* suppress automagic control of value when set.
*/
} knob_t;
/* helper for modules automating knob controls, use this to
* change values intead of direct manipulation to respect active.
* returns new (or unchanged) value
*/
static inline float knob_auto_set(knob_t *knob, float value)
{
assert(knob);
if (knob->managed)
return knob->value;
return knob->value = value;
}
/* identical to knob_auto_set, except adds to existing value.
*/
static inline float knob_auto_add(knob_t *knob, float value)
{
assert(knob);
return knob_auto_set(knob, knob->value + value);
}
/* identical to knob_auto* variants, except intended for
* external knob-twisters, i.e. the "managed" knob entrypoints.
*/
static inline float knob_set(knob_t *knob, float value)
{
assert(knob);
knob->managed = 1;
return knob->value = value;
}
static inline float knob_add(knob_t *knob, float value)
{
assert(knob);
return knob_set(knob, knob->value + value);
}
#endif
|
