knobs: add experimental rudimentary knobs API

This is intended for modules to expose bindings for floats affecting
rendering output that may be varied at runtime frame-to-frame.

See the comment in knobs.h for more information.

This commit only introduces the concept, no modules utilize it yet.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/rototiller.h b/src/rototiller.h
index e13a29a..e185624 100644
--- a/src/rototiller.h
+++ b/src/rototiller.h
@@ -18,7 +18,7 @@ typedef struct rototiller_module_t {
 	void	(*render_fragment)(void *context, unsigned ticks, unsigned cpu, fb_fragment_t *fragment);
 	void	(*finish_frame)(void *context, unsigned ticks, fb_fragment_t *fragment);
 	int	(*setup)(const settings_t *settings, setting_desc_t **next_setting);
-	knob_t *(*knobs)(void *context);	/* when present, returns NULL-terminated array knobs for the supplied context, not to be freed - likely context-resident. */
+	size_t	(*knobs)(void *context, knob_t **res_knobs);
 	char	*name;
 	char	*description;
 	char	*author;