libobs: Add function to get current transition time

libobs/obs-source-transition.c

@@ -445,6 +445,11 @@ static inline float get_video_time(obs_source_t *transition)
 	return calc_time(transition, ts);
 }
 
+float obs_transition_get_time(obs_source_t *transition)
+{
+	return get_video_time(transition);
+}
+
 static inline gs_texture_t *get_texture(obs_source_t *transition,
 		enum obs_transition_target target)
 {

libobs/obs.h

@@ -1165,6 +1165,8 @@ typedef void (*obs_transition_video_render_callback_t)(void *data,
 		uint32_t cx, uint32_t cy);
 typedef float (*obs_transition_audio_mix_callback_t)(void *data, float t);
 
+EXPORT float obs_transition_get_time(obs_source_t *transition);
+
 EXPORT void obs_transition_video_render(obs_source_t *transition,
 		obs_transition_video_render_callback_t callback);