libobs: Allow filters to specify technique

libobs/obs.h

@@ -954,6 +954,17 @@ EXPORT void obs_source_process_filter_begin(obs_source_t *filter,
 EXPORT void obs_source_process_filter_end(obs_source_t *filter,
 		gs_effect_t *effect, uint32_t width, uint32_t height);
 
+/**
+ * Draws the filter with a specific technique.
+ *
+ * Before calling this function, first call obs_source_process_filter_begin and
+ * then set the effect parameters, and then call this function to finalize the
+ * filter.
+ */
+EXPORT void obs_source_process_filter_tech_end(obs_source_t *filter,
+		gs_effect_t *effect, uint32_t width, uint32_t height,
+		const char *tech_name);
+
 /** Skips the filter if the filter is invalid and cannot be rendered */
 EXPORT void obs_source_skip_video_filter(obs_source_t *filter);