til: introduce til_module_t.render_proxy() method

Like til_module_t.render_audio(), this hooks into the render path
without triggering the implicit fragment clearing of the usual
render_fragment/prepare_frame/finish_frame methods.

But unlike render_audio(), it receives the full suite of
parameters including the fragment pointer.

The impetus for this is implementing builtins that serve as a
sort of pass-thru or proxy to another module, like the "ref"
builtin (which should probably change to use this instead of its
current render_fragment() hook).  Because sometimes the proxied
module isn't something drawing to the fragment, so the implicit
fragment clearing shouldn't occur.  But if the proxied module
/does/ touch the fragment by implementing one of those methods,
then the proxy module's use of til_module_render() would still
trigger the implicit clear when appropriate.

2 files changed, 3 insertions, 0 deletions

diff --git a/src/til.c b/src/til.c
index 9355f5f..e7de53d 100644
--- a/src/til.c
+++ b/src/til.c
@@ -297,6 +297,8 @@ static void _til_module_render(til_module_context_t *context, til_stream_t *stre
 	 */
 	if (context->module->render_audio)
 		context->module->render_audio(context, stream, ticks);
+	else if (context->module->render_proxy)
+		context->module->render_proxy(context, stream, ticks, fragment_ptr);
 	else
 		module_render_fragment(context, stream, til_threads, n_cpus, ticks, fragment_ptr);
 
diff --git a/src/til.h b/src/til.h
index 0724bf3..08b2173 100644
--- a/src/til.h
+++ b/src/til.h
@@ -31,6 +31,7 @@ struct til_module_t {
 	til_module_context_t *	(*create_context)(const til_module_t *module, til_stream_t *stream, unsigned seed, unsigned ticks, unsigned n_cpus, til_setup_t *setup);
 	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			(*render_audio)(til_module_context_t *context, til_stream_t *stream, unsigned ticks);
+	void			(*render_proxy)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr);
 	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);
 	int			(*finish_frame)(til_module_context_t *context, til_stream_t *stream, unsigned ticks, til_fb_fragment_t **fragment_ptr);