til: support multi-pass rendering

Modules can now use the til_module_t.finish_frame() return value
to trigger re-rendering by returning 1, returning 0 finishes the
frame.

A smattering of til_module_t.finish_frame() implementations were
largely mechanically updated to match this change by returning 0,
since nothing actually uses multi-pass rendering yet.

The impetus for this is experimenting with the flow module doing
two passes of threaded rendering per frame.  A first pass to
sample the flow field and update the elements, per-cpu, but
drawing nothing.  Then a second pass to render the elements in a
tiled manner.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/til.h b/src/til.h
index 0d48239..9fb8b5b 100644
--- a/src/til.h
+++ b/src/til.h
@@ -30,7 +30,7 @@ struct til_module_t {
 	void			(*destroy_context)(til_module_context_t *context);	/* destroy gets stream in context, but the render-related functions should always use the passed-in stream so it can potentially change */
 	void			(*prepare_frame)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr, til_frame_plan_t *res_frame_plan);
 	void			(*render_fragment)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, unsigned cpu, til_fb_fragment_t **fragment_ptr);
-	void			(*finish_frame)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr);
+	int			(*finish_frame)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr);
 	int			(*setup)(const til_settings_t *settings, til_setting_t **res_setting, const til_setting_desc_t **res_desc, til_setup_t **res_setup);
 	char			*name;
 	char			*description;