play: introduce play_run_slice()HEADmaster

Sometimes a more granular main loop integration is required.
In such situations play_run() taking over is untenable, so this
splits out the body of play_run()'s loop as a separately callable
function.  Existing main loops can use this to run the play main
loop for a single slice.

The impetus for this has been experimenting with escripten
support in SARS, e.g.

emscripten_set_main_loop_arg((void(*)(void *))play_run_slice, play, -1, 1);

1 files changed, 1 insertions, 0 deletions

diff --git a/src/play.h b/src/play.h
index 1d4ec6b..b3c56b5 100644
--- a/src/play.h
+++ b/src/play.h
@@ -57,6 +57,7 @@ typedef struct play_ops_t {
 
 play_t * play_startup(int argc, char *argv[], unsigned flags, const play_ops_t *ops[]);
 int play_shutdown(play_t *play);
+int play_run_slice(play_t *play);
 void play_run(play_t *play);
 
 void play_music_set(play_t *play, unsigned flags, const char *fmt, ...);